Society of Surgical Oncology (SSO): Annual Cancer Symposium

SAN ANTONIO – Lymphovascular invasion, not sentinel lymph node status, was strongly associated with recurrence and death from Merkel cell carcinoma in a series of 153 patients with clinically localized disease.

Patients without lymphatic vascular invasion (LVI) of their primary tumors did not develop recurrence or die, said Dr. Ryan Fields of the department of surgery at Memorial Sloan-Kettering Cancer Center, New York.

Although sentinel lymph node (SLN) status was not associated with recurrence or death from Merkel cell carcinoma (MCC), patients with a positive SLN were more likely to receive subsequent treatment including complete lymph node dissection, nodal radiation therapy, and/or chemotherapy.

Dr. Fields suggested that one explanation for the surprising lack of association with SLN status may be the additional treatment received by SLN-positive patients was so effective as to interrupt the metastatic cascade and prevent recurrence or death from MCC.

During a discussion of the study, Dr. Kelly McMasters, professor and chair of surgery at the University of Louisville in Kentucky, expressed doubt that adjuvant therapy was so effective as to skew the results and asked whether clinicians should biopsy their next MCC patient or whether this may simply lead them to overtreat their patients.

Dr. Fields acknowledged that the results are puzzling and said that all patients with MCC continue to be offered SLN biopsy at Memorial Sloan-Kettering, where the study was performed. He added that surgeons there are also trying to capture information on LVI to determine in which patients LVI could be used in lieu of SLN biopsy as a prognostic marker.

There is no universally accepted staging system for MCC, a rare cutaneous cancer that has a propensity for lymphatic spread. SLN biopsy has been used in an effort to provide more accurate staging and to guide subsequent treatment, although most studies have been small and did not look at outcome at the time of SLN status, he explained.

A previous analysis of 251 MCC patients treated from 1970 to 2002 at Memorial Sloan-Kettering reported that disease stage was the only independent predictor of survival and that stage-specific survival was decreased in patients with node-positive disease (J. Clin. Oncol. 2005;23:2300-9).

In the current analysis from 1996 to 2010, a total of 153 patients with stage I or II MCC underwent SLN biopsy, of which 45 (29%) were positive and 108 (71%) were negative.

The primary tumor was 2 cm or less (clinical stage I) in 122 patients and more than 2 cm (clinical stage II) in 31 patients. LVI was present in the primary tumor in 75 patients, absent in 69, and unknown in 9.

A positive SLN biopsy was significantly associated with stage II vs. stage I tumors (45% vs. 25%, P = .02), and with LVI vs. LVI absence (55% vs. 4%, P less than .01). Notably, 26% of positive SLNs occurred in tumors 1 cm or less, observed Dr. Fields.

After a median follow-up of 41 months, 16 nodal or distant recurrences occurred, 11 patients died of MCC, and 27 patients died of other causes.

"This highlights the fact that overall survival, which has been used quite a bit as an end point in Merkel cell cancers, is a poor end point measure in this population," Dr. Fields said.

Importantly, there were no nodal recurrences in SLN-positive patients who went on to receive adjuvant nodal radiation therapy after completion lymph node dissection or therapeutic radiotherapy alone.

Only two of the 32 SLN-positive patients (6%) who received no adjuvant chemotherapy developed a distant recurrence, suggesting that unproven adjuvant chemotherapy would be unlikely to benefit this patient population, Dr. Fields said.

Among the 108 patients with a negative SLN, 99 received no further treatment. Of these, 8% experienced a recurrence, which corresponds to a 15% false-negative rate for the SLNB procedure in MCC, he said.

When patients were stratified by tumor characteristics, there was no significant association between SLN-positive and SLN-negative patients in nodal/distant recurrence (P = .86) or death from MCC (P = .89). The association was significantly between stage II and stage I tumors for death (P =.05), but not for recurrence (P = .26).

In contrast, the presence of LVI was significantly associated with both nodal/distant recurrence and death from MCC (both P less than .001), Dr. Fields said. The 2-year confidence intervals of recurrence or death from MCC for LVI-positive patients were 30% and 15%, respectively.

Dr. Fields and his coauthors reported no study support or relevant conflicts of interest.

SAN ANTONIO – Lymphovascular invasion, not sentinel lymph node status, was strongly associated with recurrence and death from Merkel cell carcinoma in a series of 153 patients with clinically localized disease.

Patients without lymphatic vascular invasion (LVI) of their primary tumors did not develop recurrence or die, said Dr. Ryan Fields of the department of surgery at Memorial Sloan-Kettering Cancer Center, New York.

Although sentinel lymph node (SLN) status was not associated with recurrence or death from Merkel cell carcinoma (MCC), patients with a positive SLN were more likely to receive subsequent treatment including complete lymph node dissection, nodal radiation therapy, and/or chemotherapy.

Dr. Fields suggested that one explanation for the surprising lack of association with SLN status may be the additional treatment received by SLN-positive patients was so effective as to interrupt the metastatic cascade and prevent recurrence or death from MCC.

During a discussion of the study, Dr. Kelly McMasters, professor and chair of surgery at the University of Louisville in Kentucky, expressed doubt that adjuvant therapy was so effective as to skew the results and asked whether clinicians should biopsy their next MCC patient or whether this may simply lead them to overtreat their patients.

Dr. Fields acknowledged that the results are puzzling and said that all patients with MCC continue to be offered SLN biopsy at Memorial Sloan-Kettering, where the study was performed. He added that surgeons there are also trying to capture information on LVI to determine in which patients LVI could be used in lieu of SLN biopsy as a prognostic marker.

There is no universally accepted staging system for MCC, a rare cutaneous cancer that has a propensity for lymphatic spread. SLN biopsy has been used in an effort to provide more accurate staging and to guide subsequent treatment, although most studies have been small and did not look at outcome at the time of SLN status, he explained.

A previous analysis of 251 MCC patients treated from 1970 to 2002 at Memorial Sloan-Kettering reported that disease stage was the only independent predictor of survival and that stage-specific survival was decreased in patients with node-positive disease (J. Clin. Oncol. 2005;23:2300-9).

In the current analysis from 1996 to 2010, a total of 153 patients with stage I or II MCC underwent SLN biopsy, of which 45 (29%) were positive and 108 (71%) were negative.

The primary tumor was 2 cm or less (clinical stage I) in 122 patients and more than 2 cm (clinical stage II) in 31 patients. LVI was present in the primary tumor in 75 patients, absent in 69, and unknown in 9.

A positive SLN biopsy was significantly associated with stage II vs. stage I tumors (45% vs. 25%, P = .02), and with LVI vs. LVI absence (55% vs. 4%, P less than .01). Notably, 26% of positive SLNs occurred in tumors 1 cm or less, observed Dr. Fields.

After a median follow-up of 41 months, 16 nodal or distant recurrences occurred, 11 patients died of MCC, and 27 patients died of other causes.

"This highlights the fact that overall survival, which has been used quite a bit as an end point in Merkel cell cancers, is a poor end point measure in this population," Dr. Fields said.

Importantly, there were no nodal recurrences in SLN-positive patients who went on to receive adjuvant nodal radiation therapy after completion lymph node dissection or therapeutic radiotherapy alone.

Only two of the 32 SLN-positive patients (6%) who received no adjuvant chemotherapy developed a distant recurrence, suggesting that unproven adjuvant chemotherapy would be unlikely to benefit this patient population, Dr. Fields said.

Among the 108 patients with a negative SLN, 99 received no further treatment. Of these, 8% experienced a recurrence, which corresponds to a 15% false-negative rate for the SLNB procedure in MCC, he said.

When patients were stratified by tumor characteristics, there was no significant association between SLN-positive and SLN-negative patients in nodal/distant recurrence (P = .86) or death from MCC (P = .89). The association was significantly between stage II and stage I tumors for death (P =.05), but not for recurrence (P = .26).

In contrast, the presence of LVI was significantly associated with both nodal/distant recurrence and death from MCC (both P less than .001), Dr. Fields said. The 2-year confidence intervals of recurrence or death from MCC for LVI-positive patients were 30% and 15%, respectively.

Dr. Fields and his coauthors reported no study support or relevant conflicts of interest.

SAN ANTONIO – Lymphovascular invasion, not sentinel lymph node status, was strongly associated with recurrence and death from Merkel cell carcinoma in a series of 153 patients with clinically localized disease.

Patients without lymphatic vascular invasion (LVI) of their primary tumors did not develop recurrence or die, said Dr. Ryan Fields of the department of surgery at Memorial Sloan-Kettering Cancer Center, New York.

Although sentinel lymph node (SLN) status was not associated with recurrence or death from Merkel cell carcinoma (MCC), patients with a positive SLN were more likely to receive subsequent treatment including complete lymph node dissection, nodal radiation therapy, and/or chemotherapy.

Dr. Fields suggested that one explanation for the surprising lack of association with SLN status may be the additional treatment received by SLN-positive patients was so effective as to interrupt the metastatic cascade and prevent recurrence or death from MCC.

During a discussion of the study, Dr. Kelly McMasters, professor and chair of surgery at the University of Louisville in Kentucky, expressed doubt that adjuvant therapy was so effective as to skew the results and asked whether clinicians should biopsy their next MCC patient or whether this may simply lead them to overtreat their patients.

Dr. Fields acknowledged that the results are puzzling and said that all patients with MCC continue to be offered SLN biopsy at Memorial Sloan-Kettering, where the study was performed. He added that surgeons there are also trying to capture information on LVI to determine in which patients LVI could be used in lieu of SLN biopsy as a prognostic marker.

There is no universally accepted staging system for MCC, a rare cutaneous cancer that has a propensity for lymphatic spread. SLN biopsy has been used in an effort to provide more accurate staging and to guide subsequent treatment, although most studies have been small and did not look at outcome at the time of SLN status, he explained.

A previous analysis of 251 MCC patients treated from 1970 to 2002 at Memorial Sloan-Kettering reported that disease stage was the only independent predictor of survival and that stage-specific survival was decreased in patients with node-positive disease (J. Clin. Oncol. 2005;23:2300-9).

In the current analysis from 1996 to 2010, a total of 153 patients with stage I or II MCC underwent SLN biopsy, of which 45 (29%) were positive and 108 (71%) were negative.

The primary tumor was 2 cm or less (clinical stage I) in 122 patients and more than 2 cm (clinical stage II) in 31 patients. LVI was present in the primary tumor in 75 patients, absent in 69, and unknown in 9.

A positive SLN biopsy was significantly associated with stage II vs. stage I tumors (45% vs. 25%, P = .02), and with LVI vs. LVI absence (55% vs. 4%, P less than .01). Notably, 26% of positive SLNs occurred in tumors 1 cm or less, observed Dr. Fields.

After a median follow-up of 41 months, 16 nodal or distant recurrences occurred, 11 patients died of MCC, and 27 patients died of other causes.

"This highlights the fact that overall survival, which has been used quite a bit as an end point in Merkel cell cancers, is a poor end point measure in this population," Dr. Fields said.

Importantly, there were no nodal recurrences in SLN-positive patients who went on to receive adjuvant nodal radiation therapy after completion lymph node dissection or therapeutic radiotherapy alone.

Only two of the 32 SLN-positive patients (6%) who received no adjuvant chemotherapy developed a distant recurrence, suggesting that unproven adjuvant chemotherapy would be unlikely to benefit this patient population, Dr. Fields said.

Among the 108 patients with a negative SLN, 99 received no further treatment. Of these, 8% experienced a recurrence, which corresponds to a 15% false-negative rate for the SLNB procedure in MCC, he said.

When patients were stratified by tumor characteristics, there was no significant association between SLN-positive and SLN-negative patients in nodal/distant recurrence (P = .86) or death from MCC (P = .89). The association was significantly between stage II and stage I tumors for death (P =.05), but not for recurrence (P = .26).

In contrast, the presence of LVI was significantly associated with both nodal/distant recurrence and death from MCC (both P less than .001), Dr. Fields said. The 2-year confidence intervals of recurrence or death from MCC for LVI-positive patients were 30% and 15%, respectively.

Dr. Fields and his coauthors reported no study support or relevant conflicts of interest.

SAN ANTONIO – Lymphovascular invasion, not sentinel lymph node status, was strongly associated with recurrence and death from Merkel cell carcinoma in a series of 153 patients with clinically localized disease.

Patients without lymphatic vascular invasion (LVI) of their primary tumors did not develop recurrence or die, said Dr. Ryan Fields of the department of surgery at Memorial Sloan-Kettering Cancer Center, New York.

Although sentinel lymph node (SLN) status was not associated with recurrence or death from Merkel cell carcinoma (MCC), patients with a positive SLN were more likely to receive subsequent treatment including complete lymph node dissection, nodal radiation therapy, and/or chemotherapy.

Dr. Fields suggested that one explanation for the surprising lack of association with SLN status may be the additional treatment received by SLN-positive patients was so effective as to interrupt the metastatic cascade and prevent recurrence or death from MCC.

During a discussion of the study, Dr. Kelly McMasters, professor and chair of surgery at the University of Louisville in Kentucky, expressed doubt that adjuvant therapy was so effective as to skew the results and asked whether clinicians should biopsy their next MCC patient or whether this may simply lead them to overtreat their patients.

Dr. Fields acknowledged that the results are puzzling and said that all patients with MCC continue to be offered SLN biopsy at Memorial Sloan-Kettering, where the study was performed. He added that surgeons there are also trying to capture information on LVI to determine in which patients LVI could be used in lieu of SLN biopsy as a prognostic marker.

There is no universally accepted staging system for MCC, a rare cutaneous cancer that has a propensity for lymphatic spread. SLN biopsy has been used in an effort to provide more accurate staging and to guide subsequent treatment, although most studies have been small and did not look at outcome at the time of SLN status, he explained.

A previous analysis of 251 MCC patients treated from 1970 to 2002 at Memorial Sloan-Kettering reported that disease stage was the only independent predictor of survival and that stage-specific survival was decreased in patients with node-positive disease (J. Clin. Oncol. 2005;23:2300-9).

In the current analysis from 1996 to 2010, a total of 153 patients with stage I or II MCC underwent SLN biopsy, of which 45 (29%) were positive and 108 (71%) were negative.

The primary tumor was 2 cm or less (clinical stage I) in 122 patients and more than 2 cm (clinical stage II) in 31 patients. LVI was present in the primary tumor in 75 patients, absent in 69, and unknown in 9.

A positive SLN biopsy was significantly associated with stage II vs. stage I tumors (45% vs. 25%, P = .02), and with LVI vs. LVI absence (55% vs. 4%, P less than .01). Notably, 26% of positive SLNs occurred in tumors 1 cm or less, observed Dr. Fields.

After a median follow-up of 41 months, 16 nodal or distant recurrences occurred, 11 patients died of MCC, and 27 patients died of other causes.

"This highlights the fact that overall survival, which has been used quite a bit as an end point in Merkel cell cancers, is a poor end point measure in this population," Dr. Fields said.

Importantly, there were no nodal recurrences in SLN-positive patients who went on to receive adjuvant nodal radiation therapy after completion lymph node dissection or therapeutic radiotherapy alone.

Only two of the 32 SLN-positive patients (6%) who received no adjuvant chemotherapy developed a distant recurrence, suggesting that unproven adjuvant chemotherapy would be unlikely to benefit this patient population, Dr. Fields said.

Among the 108 patients with a negative SLN, 99 received no further treatment. Of these, 8% experienced a recurrence, which corresponds to a 15% false-negative rate for the SLNB procedure in MCC, he said.

When patients were stratified by tumor characteristics, there was no significant association between SLN-positive and SLN-negative patients in nodal/distant recurrence (P = .86) or death from MCC (P = .89). The association was significantly between stage II and stage I tumors for death (P =.05), but not for recurrence (P = .26).

In contrast, the presence of LVI was significantly associated with both nodal/distant recurrence and death from MCC (both P less than .001), Dr. Fields said. The 2-year confidence intervals of recurrence or death from MCC for LVI-positive patients were 30% and 15%, respectively.

Dr. Fields and his coauthors reported no study support or relevant conflicts of interest.

SAN ANTONIO – Lymphovascular invasion, not sentinel lymph node status, was strongly associated with recurrence and death from Merkel cell carcinoma in a series of 153 patients with clinically localized disease.

Patients without lymphatic vascular invasion (LVI) of their primary tumors did not develop recurrence or die, said Dr. Ryan Fields of the department of surgery at Memorial Sloan-Kettering Cancer Center, New York.

Although sentinel lymph node (SLN) status was not associated with recurrence or death from Merkel cell carcinoma (MCC), patients with a positive SLN were more likely to receive subsequent treatment including complete lymph node dissection, nodal radiation therapy, and/or chemotherapy.

Dr. Fields suggested that one explanation for the surprising lack of association with SLN status may be the additional treatment received by SLN-positive patients was so effective as to interrupt the metastatic cascade and prevent recurrence or death from MCC.

During a discussion of the study, Dr. Kelly McMasters, professor and chair of surgery at the University of Louisville in Kentucky, expressed doubt that adjuvant therapy was so effective as to skew the results and asked whether clinicians should biopsy their next MCC patient or whether this may simply lead them to overtreat their patients.

Dr. Fields acknowledged that the results are puzzling and said that all patients with MCC continue to be offered SLN biopsy at Memorial Sloan-Kettering, where the study was performed. He added that surgeons there are also trying to capture information on LVI to determine in which patients LVI could be used in lieu of SLN biopsy as a prognostic marker.

There is no universally accepted staging system for MCC, a rare cutaneous cancer that has a propensity for lymphatic spread. SLN biopsy has been used in an effort to provide more accurate staging and to guide subsequent treatment, although most studies have been small and did not look at outcome at the time of SLN status, he explained.

A previous analysis of 251 MCC patients treated from 1970 to 2002 at Memorial Sloan-Kettering reported that disease stage was the only independent predictor of survival and that stage-specific survival was decreased in patients with node-positive disease (J. Clin. Oncol. 2005;23:2300-9).

In the current analysis from 1996 to 2010, a total of 153 patients with stage I or II MCC underwent SLN biopsy, of which 45 (29%) were positive and 108 (71%) were negative.

The primary tumor was 2 cm or less (clinical stage I) in 122 patients and more than 2 cm (clinical stage II) in 31 patients. LVI was present in the primary tumor in 75 patients, absent in 69, and unknown in 9.

A positive SLN biopsy was significantly associated with stage II vs. stage I tumors (45% vs. 25%, P = .02), and with LVI vs. LVI absence (55% vs. 4%, P less than .01). Notably, 26% of positive SLNs occurred in tumors 1 cm or less, observed Dr. Fields.

After a median follow-up of 41 months, 16 nodal or distant recurrences occurred, 11 patients died of MCC, and 27 patients died of other causes.

"This highlights the fact that overall survival, which has been used quite a bit as an end point in Merkel cell cancers, is a poor end point measure in this population," Dr. Fields said.

Importantly, there were no nodal recurrences in SLN-positive patients who went on to receive adjuvant nodal radiation therapy after completion lymph node dissection or therapeutic radiotherapy alone.

Only two of the 32 SLN-positive patients (6%) who received no adjuvant chemotherapy developed a distant recurrence, suggesting that unproven adjuvant chemotherapy would be unlikely to benefit this patient population, Dr. Fields said.

Among the 108 patients with a negative SLN, 99 received no further treatment. Of these, 8% experienced a recurrence, which corresponds to a 15% false-negative rate for the SLNB procedure in MCC, he said.

When patients were stratified by tumor characteristics, there was no significant association between SLN-positive and SLN-negative patients in nodal/distant recurrence (P = .86) or death from MCC (P = .89). The association was significantly between stage II and stage I tumors for death (P =.05), but not for recurrence (P = .26).

In contrast, the presence of LVI was significantly associated with both nodal/distant recurrence and death from MCC (both P less than .001), Dr. Fields said. The 2-year confidence intervals of recurrence or death from MCC for LVI-positive patients were 30% and 15%, respectively.

Dr. Fields and his coauthors reported no study support or relevant conflicts of interest.

SAN ANTONIO – Lymphovascular invasion, not sentinel lymph node status, was strongly associated with recurrence and death from Merkel cell carcinoma in a series of 153 patients with clinically localized disease.

Patients without lymphatic vascular invasion (LVI) of their primary tumors did not develop recurrence or die, said Dr. Ryan Fields of the department of surgery at Memorial Sloan-Kettering Cancer Center, New York.

Although sentinel lymph node (SLN) status was not associated with recurrence or death from Merkel cell carcinoma (MCC), patients with a positive SLN were more likely to receive subsequent treatment including complete lymph node dissection, nodal radiation therapy, and/or chemotherapy.

Dr. Fields suggested that one explanation for the surprising lack of association with SLN status may be the additional treatment received by SLN-positive patients was so effective as to interrupt the metastatic cascade and prevent recurrence or death from MCC.

During a discussion of the study, Dr. Kelly McMasters, professor and chair of surgery at the University of Louisville in Kentucky, expressed doubt that adjuvant therapy was so effective as to skew the results and asked whether clinicians should biopsy their next MCC patient or whether this may simply lead them to overtreat their patients.

Dr. Fields acknowledged that the results are puzzling and said that all patients with MCC continue to be offered SLN biopsy at Memorial Sloan-Kettering, where the study was performed. He added that surgeons there are also trying to capture information on LVI to determine in which patients LVI could be used in lieu of SLN biopsy as a prognostic marker.

There is no universally accepted staging system for MCC, a rare cutaneous cancer that has a propensity for lymphatic spread. SLN biopsy has been used in an effort to provide more accurate staging and to guide subsequent treatment, although most studies have been small and did not look at outcome at the time of SLN status, he explained.

A previous analysis of 251 MCC patients treated from 1970 to 2002 at Memorial Sloan-Kettering reported that disease stage was the only independent predictor of survival and that stage-specific survival was decreased in patients with node-positive disease (J. Clin. Oncol. 2005;23:2300-9).

In the current analysis from 1996 to 2010, a total of 153 patients with stage I or II MCC underwent SLN biopsy, of which 45 (29%) were positive and 108 (71%) were negative.

The primary tumor was 2 cm or less (clinical stage I) in 122 patients and more than 2 cm (clinical stage II) in 31 patients. LVI was present in the primary tumor in 75 patients, absent in 69, and unknown in 9.

A positive SLN biopsy was significantly associated with stage II vs. stage I tumors (45% vs. 25%, P = .02), and with LVI vs. LVI absence (55% vs. 4%, P less than .01). Notably, 26% of positive SLNs occurred in tumors 1 cm or less, observed Dr. Fields.

After a median follow-up of 41 months, 16 nodal or distant recurrences occurred, 11 patients died of MCC, and 27 patients died of other causes.

"This highlights the fact that overall survival, which has been used quite a bit as an end point in Merkel cell cancers, is a poor end point measure in this population," Dr. Fields said.

Importantly, there were no nodal recurrences in SLN-positive patients who went on to receive adjuvant nodal radiation therapy after completion lymph node dissection or therapeutic radiotherapy alone.

Only two of the 32 SLN-positive patients (6%) who received no adjuvant chemotherapy developed a distant recurrence, suggesting that unproven adjuvant chemotherapy would be unlikely to benefit this patient population, Dr. Fields said.

Among the 108 patients with a negative SLN, 99 received no further treatment. Of these, 8% experienced a recurrence, which corresponds to a 15% false-negative rate for the SLNB procedure in MCC, he said.

When patients were stratified by tumor characteristics, there was no significant association between SLN-positive and SLN-negative patients in nodal/distant recurrence (P = .86) or death from MCC (P = .89). The association was significantly between stage II and stage I tumors for death (P =.05), but not for recurrence (P = .26).

In contrast, the presence of LVI was significantly associated with both nodal/distant recurrence and death from MCC (both P less than .001), Dr. Fields said. The 2-year confidence intervals of recurrence or death from MCC for LVI-positive patients were 30% and 15%, respectively.

Dr. Fields and his coauthors reported no study support or relevant conflicts of interest.

SAN ANTONIO – Lymphovascular invasion, not sentinel lymph node status, was strongly associated with recurrence and death from Merkel cell carcinoma in a series of 153 patients with clinically localized disease.

Patients without lymphatic vascular invasion (LVI) of their primary tumors did not develop recurrence or die, said Dr. Ryan Fields of the department of surgery at Memorial Sloan-Kettering Cancer Center, New York.

Although sentinel lymph node (SLN) status was not associated with recurrence or death from Merkel cell carcinoma (MCC), patients with a positive SLN were more likely to receive subsequent treatment including complete lymph node dissection, nodal radiation therapy, and/or chemotherapy.

Dr. Fields suggested that one explanation for the surprising lack of association with SLN status may be the additional treatment received by SLN-positive patients was so effective as to interrupt the metastatic cascade and prevent recurrence or death from MCC.

During a discussion of the study, Dr. Kelly McMasters, professor and chair of surgery at the University of Louisville in Kentucky, expressed doubt that adjuvant therapy was so effective as to skew the results and asked whether clinicians should biopsy their next MCC patient or whether this may simply lead them to over treat their patients.

Dr. Fields acknowledged that the results are puzzling and said that all patients with MCC continue to be offered SLN biopsy at Memorial Sloan-Kettering, where the study was performed. He added that surgeons there are also trying to capture information on LVI to determine in which patients LVI could be used in lieu of SLN biopsy as a prognostic marker.

There is no universally accepted staging system for MCC, a rare cutaneous cancer that has a propensity for lymphatic spread. SLN biopsy has been used in an effort to provide more accurate staging and to guide subsequent treatment, although most studies have been small and did not look at outcome at the time of SLN status, he explained.

A previous analysis of 251 MCC patients treated from 1970 to 2002 at Memorial Sloan-Kettering reported that disease stage was the only independent predictor of survival and that stage-specific survival was decreased in patients with node-positive disease (J. Clin. Oncol. 2005;23:2300-9).

In the current analysis from 1996 to 2010, a total of 153 patients with stage I or II MCC underwent SLN biopsy, of which 45 (29%) were positive and 108 (71%) were negative.

The primary tumor was 2 cm or less (clinical stage I) in 122 patients and more than 2 cm (clinical stage II) in 31 patients. LVI was present in the primary tumor in 75 patients, absent in 69, and unknown in 9.

A positive SLN biopsy was significantly associated with stage II vs. stage I tumors (45% vs. 25%, P = .02), and with LVI vs. LVI absence (55% vs. 4%, P less than .01). Notably, 26% of positive SLNs occurred in tumors 1 cm or less, observed Dr. Fields.

After a median follow-up of 41 months, 16 nodal or distant recurrences occurred, 11 patients died of MCC, and 27 patients died of other causes.

"This highlights the fact that overall survival, which has been used quite a bit as an end point in Merkel cell cancers, is a poor end point measure in this population," Dr. Fields said.

Importantly, there were no nodal recurrences in SLN-positive patients who went on to receive adjuvant nodal radiation therapy after completion lymph node dissection or therapeutic radiotherapy alone.

Only two of the 32 SLN-positive patients (6%) who received no adjuvant chemotherapy developed a distant recurrence, suggesting that unproven adjuvant chemotherapy would be unlikely to benefit this patient population, Dr. Fields said.

Among the 108 patients with a negative SLN, 99 received no further treatment. Of these, 8% experienced a recurrence, which corresponds to a 15% false-negative rate for the SLNB procedure in MCC, he said.

When patients were stratified by tumor characteristics, there was no significant association between SLN-positive and SLN-negative patients in nodal/distant recurrence (P = .86) or death from MCC (P = .89). The association was significantly between stage II and stage I tumors for death (P =.05), but not for recurrence (P = .26).

In contrast, the presence of LVI was significantly associated with both nodal/distant recurrence and death from MCC (both P less than .001), Dr. Fields said. The 2-year confidence intervals of recurrence or death from MCC for LVI-positive patients were 30% and 15%, respectively.

Dr. Fields and his coauthors reported no study support or relevant conflicts of interest.

SAN ANTONIO – Lymphovascular invasion, not sentinel lymph node status, was strongly associated with recurrence and death from Merkel cell carcinoma in a series of 153 patients with clinically localized disease.

Patients without lymphatic vascular invasion (LVI) of their primary tumors did not develop recurrence or die, said Dr. Ryan Fields of the department of surgery at Memorial Sloan-Kettering Cancer Center, New York.

Although sentinel lymph node (SLN) status was not associated with recurrence or death from Merkel cell carcinoma (MCC), patients with a positive SLN were more likely to receive subsequent treatment including complete lymph node dissection, nodal radiation therapy, and/or chemotherapy.

Dr. Fields suggested that one explanation for the surprising lack of association with SLN status may be the additional treatment received by SLN-positive patients was so effective as to interrupt the metastatic cascade and prevent recurrence or death from MCC.

During a discussion of the study, Dr. Kelly McMasters, professor and chair of surgery at the University of Louisville in Kentucky, expressed doubt that adjuvant therapy was so effective as to skew the results and asked whether clinicians should biopsy their next MCC patient or whether this may simply lead them to over treat their patients.

Dr. Fields acknowledged that the results are puzzling and said that all patients with MCC continue to be offered SLN biopsy at Memorial Sloan-Kettering, where the study was performed. He added that surgeons there are also trying to capture information on LVI to determine in which patients LVI could be used in lieu of SLN biopsy as a prognostic marker.

There is no universally accepted staging system for MCC, a rare cutaneous cancer that has a propensity for lymphatic spread. SLN biopsy has been used in an effort to provide more accurate staging and to guide subsequent treatment, although most studies have been small and did not look at outcome at the time of SLN status, he explained.

A previous analysis of 251 MCC patients treated from 1970 to 2002 at Memorial Sloan-Kettering reported that disease stage was the only independent predictor of survival and that stage-specific survival was decreased in patients with node-positive disease (J. Clin. Oncol. 2005;23:2300-9).

In the current analysis from 1996 to 2010, a total of 153 patients with stage I or II MCC underwent SLN biopsy, of which 45 (29%) were positive and 108 (71%) were negative.

The primary tumor was 2 cm or less (clinical stage I) in 122 patients and more than 2 cm (clinical stage II) in 31 patients. LVI was present in the primary tumor in 75 patients, absent in 69, and unknown in 9.

A positive SLN biopsy was significantly associated with stage II vs. stage I tumors (45% vs. 25%, P = .02), and with LVI vs. LVI absence (55% vs. 4%, P less than .01). Notably, 26% of positive SLNs occurred in tumors 1 cm or less, observed Dr. Fields.

After a median follow-up of 41 months, 16 nodal or distant recurrences occurred, 11 patients died of MCC, and 27 patients died of other causes.

"This highlights the fact that overall survival, which has been used quite a bit as an end point in Merkel cell cancers, is a poor end point measure in this population," Dr. Fields said.

Importantly, there were no nodal recurrences in SLN-positive patients who went on to receive adjuvant nodal radiation therapy after completion lymph node dissection or therapeutic radiotherapy alone.

Only two of the 32 SLN-positive patients (6%) who received no adjuvant chemotherapy developed a distant recurrence, suggesting that unproven adjuvant chemotherapy would be unlikely to benefit this patient population, Dr. Fields said.

Among the 108 patients with a negative SLN, 99 received no further treatment. Of these, 8% experienced a recurrence, which corresponds to a 15% false-negative rate for the SLNB procedure in MCC, he said.

When patients were stratified by tumor characteristics, there was no significant association between SLN-positive and SLN-negative patients in nodal/distant recurrence (P = .86) or death from MCC (P = .89). The association was significantly between stage II and stage I tumors for death (P =.05), but not for recurrence (P = .26).

In contrast, the presence of LVI was significantly associated with both nodal/distant recurrence and death from MCC (both P less than .001), Dr. Fields said. The 2-year confidence intervals of recurrence or death from MCC for LVI-positive patients were 30% and 15%, respectively.

Dr. Fields and his coauthors reported no study support or relevant conflicts of interest.

SAN ANTONIO – Lymphovascular invasion, not sentinel lymph node status, was strongly associated with recurrence and death from Merkel cell carcinoma in a series of 153 patients with clinically localized disease.

Patients without lymphatic vascular invasion (LVI) of their primary tumors did not develop recurrence or die, said Dr. Ryan Fields of the department of surgery at Memorial Sloan-Kettering Cancer Center, New York.

Although sentinel lymph node (SLN) status was not associated with recurrence or death from Merkel cell carcinoma (MCC), patients with a positive SLN were more likely to receive subsequent treatment including complete lymph node dissection, nodal radiation therapy, and/or chemotherapy.

Dr. Fields suggested that one explanation for the surprising lack of association with SLN status may be the additional treatment received by SLN-positive patients was so effective as to interrupt the metastatic cascade and prevent recurrence or death from MCC.

During a discussion of the study, Dr. Kelly McMasters, professor and chair of surgery at the University of Louisville in Kentucky, expressed doubt that adjuvant therapy was so effective as to skew the results and asked whether clinicians should biopsy their next MCC patient or whether this may simply lead them to over treat their patients.

Dr. Fields acknowledged that the results are puzzling and said that all patients with MCC continue to be offered SLN biopsy at Memorial Sloan-Kettering, where the study was performed. He added that surgeons there are also trying to capture information on LVI to determine in which patients LVI could be used in lieu of SLN biopsy as a prognostic marker.

There is no universally accepted staging system for MCC, a rare cutaneous cancer that has a propensity for lymphatic spread. SLN biopsy has been used in an effort to provide more accurate staging and to guide subsequent treatment, although most studies have been small and did not look at outcome at the time of SLN status, he explained.

A previous analysis of 251 MCC patients treated from 1970 to 2002 at Memorial Sloan-Kettering reported that disease stage was the only independent predictor of survival and that stage-specific survival was decreased in patients with node-positive disease (J. Clin. Oncol. 2005;23:2300-9).

In the current analysis from 1996 to 2010, a total of 153 patients with stage I or II MCC underwent SLN biopsy, of which 45 (29%) were positive and 108 (71%) were negative.

The primary tumor was 2 cm or less (clinical stage I) in 122 patients and more than 2 cm (clinical stage II) in 31 patients. LVI was present in the primary tumor in 75 patients, absent in 69, and unknown in 9.

A positive SLN biopsy was significantly associated with stage II vs. stage I tumors (45% vs. 25%, P = .02), and with LVI vs. LVI absence (55% vs. 4%, P less than .01). Notably, 26% of positive SLNs occurred in tumors 1 cm or less, observed Dr. Fields.

After a median follow-up of 41 months, 16 nodal or distant recurrences occurred, 11 patients died of MCC, and 27 patients died of other causes.

"This highlights the fact that overall survival, which has been used quite a bit as an end point in Merkel cell cancers, is a poor end point measure in this population," Dr. Fields said.

Importantly, there were no nodal recurrences in SLN-positive patients who went on to receive adjuvant nodal radiation therapy after completion lymph node dissection or therapeutic radiotherapy alone.

Only two of the 32 SLN-positive patients (6%) who received no adjuvant chemotherapy developed a distant recurrence, suggesting that unproven adjuvant chemotherapy would be unlikely to benefit this patient population, Dr. Fields said.

Among the 108 patients with a negative SLN, 99 received no further treatment. Of these, 8% experienced a recurrence, which corresponds to a 15% false-negative rate for the SLNB procedure in MCC, he said.

When patients were stratified by tumor characteristics, there was no significant association between SLN-positive and SLN-negative patients in nodal/distant recurrence (P = .86) or death from MCC (P = .89). The association was significantly between stage II and stage I tumors for death (P =.05), but not for recurrence (P = .26).

In contrast, the presence of LVI was significantly associated with both nodal/distant recurrence and death from MCC (both P less than .001), Dr. Fields said. The 2-year confidence intervals of recurrence or death from MCC for LVI-positive patients were 30% and 15%, respectively.

Dr. Fields and his coauthors reported no study support or relevant conflicts of interest.

SAN ANTONIO – Patients with thin melanomas and positive deep margins on initial biopsy had the same incidence of sentinel lymph node metastasis as those with thicker melanomas, according to the results of a retrospective analysis of 260 patients with melanoma.

At least one positive sentinel lymph node was detected in 6 of 73 patients (8%) with a melanoma Breslow thickness of less than 0.8 mm and positive deep margins vs. 17 of 187 patients (9%) with a melanoma Breslow thickness of 0.8-2.0 mm, regardless of margin status (P = .82).

Immunohistochemistry was the most common method of identifying positive sentinel nodes in both the thin and thick melanoma groups (5 cases vs. 10 cases, respectively), Dr. Victor Koshenkov said at a symposium sponsored by the Society of Surgical Oncology.

The decision to perform sentinel node biopsy is largely driven by tumor thickness. When the initial biopsy of a thin melanoma shows positive deep margins, many clinicians will treat these cases as potentially thicker melanomas and perform sentinel lymph node (SLN) biopsy. There are few data on the impact of positive deep margins on surgical decision making, prognosis, and outcome, even though positive deep margins are the most common cause of incompletely measured or indeterminate tumor thickness, said Dr. Koshenkov of the department of surgery at Atlantic Health Memorial Hospital in Morristown, N.J.

He presented data from a retrospective analysis of 260 adult patients who underwent wide excision plus SLN biopsy for cutaneous melanoma from January 2004 to May 2010.

Demographics were not statistically different between the two groups, except for tumor site and Clark’s level, he said. In 53% of patients in the thicker melanoma group, the extremities were the primary tumor site vs. 38% in the thin melanoma group (P = .042), while 40% had Clark’s level IV-V vs. 22% in the thin melanoma group (P less than .001).

Multivariate regression analysis revealed that only female gender (P = .046; odds ratio, 2.68) and Clark’s level IV-V (P = .024; OR, 3.54) were significantly associated with an increased risk of positive SLNs. Belonging to the thin melanoma group versus the thicker melanoma group was not significant (P = .66; OR, 1.29) Dr. Koshenkov said.

The presence of residual disease approached, but did not reach, statistical significance (P = .062; OR, 2.60). Residual disease was found in about 20% of both groups. Only 4 of the 73 patients (5.5%) with positive SLNs in the thin melanoma group required further reexcision with wide margins.

Only 1 of the 23 sentinel node–positive patients went on to have additional positive nodes on completion of lymph node dissection, he said.

"Patients with thin melanomas and positive deep margins on initial biopsy have an incidence of SLN metastasis statistically no different than patients with thicker melanomas," Dr. Koshenkov concluded. "Thus, we believe that thin melanomas with positive deep margins should be treated with wide excision and a sentinel lymph node biopsy. Of course, these findings should be tested and verified in larger, multi-institutional databases."

During a discussion of the study, the audience questioned the ability to make almost a practice-changing conclusion based on the small number of patients and the low incidence of positive SLNs in the thicker melanoma group. Dr. Koshenkov replied that the reason the rate of sentinel node positivity was lower than predicted in this group was that a larger proportion of patients had melanomas 0.8-1 mm in depth, rather than 1-2 mm in depth.

Another attendee remarked that before concluding that every patient with a positive deep margin on initial biopsy needs to undergo SLN biopsy, it is important to know how many patients with positive sentinel nodes had a positive deep margin as their only indication or whether factors such as mitotic rate or ulceration played a role. Dr. Koshenkov said mitotic rate was not analyzed because it was not regularly included in the pathology report at the time of the review, and that ulceration and Clark's level IV were factored into the multivariate analysis.

The authors said they had no relevant financial disclosures.

SAN ANTONIO – Patients with thin melanomas and positive deep margins on initial biopsy had the same incidence of sentinel lymph node metastasis as those with thicker melanomas, according to the results of a retrospective analysis of 260 patients with melanoma.

At least one positive sentinel lymph node was detected in 6 of 73 patients (8%) with a melanoma Breslow thickness of less than 0.8 mm and positive deep margins vs. 17 of 187 patients (9%) with a melanoma Breslow thickness of 0.8-2.0 mm, regardless of margin status (P = .82).

Immunohistochemistry was the most common method of identifying positive sentinel nodes in both the thin and thick melanoma groups (5 cases vs. 10 cases, respectively), Dr. Victor Koshenkov said at a symposium sponsored by the Society of Surgical Oncology.

The decision to perform sentinel node biopsy is largely driven by tumor thickness. When the initial biopsy of a thin melanoma shows positive deep margins, many clinicians will treat these cases as potentially thicker melanomas and perform sentinel lymph node (SLN) biopsy. There are few data on the impact of positive deep margins on surgical decision making, prognosis, and outcome, even though positive deep margins are the most common cause of incompletely measured or indeterminate tumor thickness, said Dr. Koshenkov of the department of surgery at Atlantic Health Memorial Hospital in Morristown, N.J.

He presented data from a retrospective analysis of 260 adult patients who underwent wide excision plus SLN biopsy for cutaneous melanoma from January 2004 to May 2010.

Demographics were not statistically different between the two groups, except for tumor site and Clark’s level, he said. In 53% of patients in the thicker melanoma group, the extremities were the primary tumor site vs. 38% in the thin melanoma group (P = .042), while 40% had Clark’s level IV-V vs. 22% in the thin melanoma group (P less than .001).

Multivariate regression analysis revealed that only female gender (P = .046; odds ratio, 2.68) and Clark’s level IV-V (P = .024; OR, 3.54) were significantly associated with an increased risk of positive SLNs. Belonging to the thin melanoma group versus the thicker melanoma group was not significant (P = .66; OR, 1.29) Dr. Koshenkov said.

The presence of residual disease approached, but did not reach, statistical significance (P = .062; OR, 2.60). Residual disease was found in about 20% of both groups. Only 4 of the 73 patients (5.5%) with positive SLNs in the thin melanoma group required further reexcision with wide margins.

Only 1 of the 23 sentinel node–positive patients went on to have additional positive nodes on completion of lymph node dissection, he said.

"Patients with thin melanomas and positive deep margins on initial biopsy have an incidence of SLN metastasis statistically no different than patients with thicker melanomas," Dr. Koshenkov concluded. "Thus, we believe that thin melanomas with positive deep margins should be treated with wide excision and a sentinel lymph node biopsy. Of course, these findings should be tested and verified in larger, multi-institutional databases."

During a discussion of the study, the audience questioned the ability to make almost a practice-changing conclusion based on the small number of patients and the low incidence of positive SLNs in the thicker melanoma group. Dr. Koshenkov replied that the reason the rate of sentinel node positivity was lower than predicted in this group was that a larger proportion of patients had melanomas 0.8-1 mm in depth, rather than 1-2 mm in depth.

Another attendee remarked that before concluding that every patient with a positive deep margin on initial biopsy needs to undergo SLN biopsy, it is important to know how many patients with positive sentinel nodes had a positive deep margin as their only indication or whether factors such as mitotic rate or ulceration played a role. Dr. Koshenkov said mitotic rate was not analyzed because it was not regularly included in the pathology report at the time of the review, and that ulceration and Clark's level IV were factored into the multivariate analysis.

The authors said they had no relevant financial disclosures.

SAN ANTONIO – Patients with thin melanomas and positive deep margins on initial biopsy had the same incidence of sentinel lymph node metastasis as those with thicker melanomas, according to the results of a retrospective analysis of 260 patients with melanoma.

At least one positive sentinel lymph node was detected in 6 of 73 patients (8%) with a melanoma Breslow thickness of less than 0.8 mm and positive deep margins vs. 17 of 187 patients (9%) with a melanoma Breslow thickness of 0.8-2.0 mm, regardless of margin status (P = .82).

Immunohistochemistry was the most common method of identifying positive sentinel nodes in both the thin and thick melanoma groups (5 cases vs. 10 cases, respectively), Dr. Victor Koshenkov said at a symposium sponsored by the Society of Surgical Oncology.

The decision to perform sentinel node biopsy is largely driven by tumor thickness. When the initial biopsy of a thin melanoma shows positive deep margins, many clinicians will treat these cases as potentially thicker melanomas and perform sentinel lymph node (SLN) biopsy. There are few data on the impact of positive deep margins on surgical decision making, prognosis, and outcome, even though positive deep margins are the most common cause of incompletely measured or indeterminate tumor thickness, said Dr. Koshenkov of the department of surgery at Atlantic Health Memorial Hospital in Morristown, N.J.

He presented data from a retrospective analysis of 260 adult patients who underwent wide excision plus SLN biopsy for cutaneous melanoma from January 2004 to May 2010.

Demographics were not statistically different between the two groups, except for tumor site and Clark’s level, he said. In 53% of patients in the thicker melanoma group, the extremities were the primary tumor site vs. 38% in the thin melanoma group (P = .042), while 40% had Clark’s level IV-V vs. 22% in the thin melanoma group (P less than .001).

Multivariate regression analysis revealed that only female gender (P = .046; odds ratio, 2.68) and Clark’s level IV-V (P = .024; OR, 3.54) were significantly associated with an increased risk of positive SLNs. Belonging to the thin melanoma group versus the thicker melanoma group was not significant (P = .66; OR, 1.29) Dr. Koshenkov said.

The presence of residual disease approached, but did not reach, statistical significance (P = .062; OR, 2.60). Residual disease was found in about 20% of both groups. Only 4 of the 73 patients (5.5%) with positive SLNs in the thin melanoma group required further reexcision with wide margins.

Only 1 of the 23 sentinel node–positive patients went on to have additional positive nodes on completion of lymph node dissection, he said.

"Patients with thin melanomas and positive deep margins on initial biopsy have an incidence of SLN metastasis statistically no different than patients with thicker melanomas," Dr. Koshenkov concluded. "Thus, we believe that thin melanomas with positive deep margins should be treated with wide excision and a sentinel lymph node biopsy. Of course, these findings should be tested and verified in larger, multi-institutional databases."

During a discussion of the study, the audience questioned the ability to make almost a practice-changing conclusion based on the small number of patients and the low incidence of positive SLNs in the thicker melanoma group. Dr. Koshenkov replied that the reason the rate of sentinel node positivity was lower than predicted in this group was that a larger proportion of patients had melanomas 0.8-1 mm in depth, rather than 1-2 mm in depth.

Another attendee remarked that before concluding that every patient with a positive deep margin on initial biopsy needs to undergo SLN biopsy, it is important to know how many patients with positive sentinel nodes had a positive deep margin as their only indication or whether factors such as mitotic rate or ulceration played a role. Dr. Koshenkov said mitotic rate was not analyzed because it was not regularly included in the pathology report at the time of the review, and that ulceration and Clark's level IV were factored into the multivariate analysis.

The authors said they had no relevant financial disclosures.

SAN ANTONIO – Patients with thin melanomas and positive deep margins on initial biopsy had the same incidence of sentinel lymph node metastasis as those with thicker melanomas, according to the results of a retrospective analysis of 260 patients with melanoma.

At least one positive sentinel lymph node was detected in 6 of 73 patients (8%) with a melanoma Breslow thickness of less than 0.8 mm and positive deep margins vs. 17 of 187 patients (9%) with a melanoma Breslow thickness of 0.8-2.0 mm, regardless of margin status (P = .82).

Immunohistochemistry was the most common method of identifying positive sentinel nodes in both the thin and thick melanoma groups (5 cases vs. 10 cases, respectively), Dr. Victor Koshenkov said at a symposium sponsored by the Society of Surgical Oncology.

The decision to perform sentinel node biopsy is largely driven by tumor thickness. When the initial biopsy of a thin melanoma shows positive deep margins, many clinicians will treat these cases as potentially thicker melanomas and perform sentinel lymph node (SLN) biopsy. There are few data on the impact of positive deep margins on surgical decision making, prognosis, and outcome, even though positive deep margins are the most common cause of incompletely measured or indeterminate tumor thickness, said Dr. Koshenkov of the department of surgery at Atlantic Health Memorial Hospital in Morristown, N.J.

He presented data from a retrospective analysis of 260 adult patients who underwent wide excision plus SLN biopsy for cutaneous melanoma from January 2004 to May 2010.

Demographics were not statistically different between the two groups, except for tumor site and Clark’s level, he said. In 53% of patients in the thicker melanoma group, the extremities were the primary tumor site vs. 38% in the thin melanoma group (P = .042), while 40% had Clark’s level IV-V vs. 22% in the thin melanoma group (P less than .001).

Multivariate regression analysis revealed that only female gender (P = .046; odds ratio, 2.68) and Clark’s level IV-V (P = .024; OR, 3.54) were significantly associated with an increased risk of positive SLNs. Belonging to the thin melanoma group versus the thicker melanoma group was not significant (P = .66; OR, 1.29) Dr. Koshenkov said.

The presence of residual disease approached, but did not reach, statistical significance (P = .062; OR, 2.60). Residual disease was found in about 20% of both groups. Only 4 of the 73 patients (5.5%) with positive SLNs in the thin melanoma group required further reexcision with wide margins.

Only 1 of the 23 sentinel node–positive patients went on to have additional positive nodes on completion of lymph node dissection, he said.

"Patients with thin melanomas and positive deep margins on initial biopsy have an incidence of SLN metastasis statistically no different than patients with thicker melanomas," Dr. Koshenkov concluded. "Thus, we believe that thin melanomas with positive deep margins should be treated with wide excision and a sentinel lymph node biopsy. Of course, these findings should be tested and verified in larger, multi-institutional databases."

During a discussion of the study, the audience questioned the ability to make almost a practice-changing conclusion based on the small number of patients and the low incidence of positive SLNs in the thicker melanoma group. Dr. Koshenkov replied that the reason the rate of sentinel node positivity was lower than predicted in this group was that a larger proportion of patients had melanomas 0.8-1 mm in depth, rather than 1-2 mm in depth.

Another attendee remarked that before concluding that every patient with a positive deep margin on initial biopsy needs to undergo SLN biopsy, it is important to know how many patients with positive sentinel nodes had a positive deep margin as their only indication or whether factors such as mitotic rate or ulceration played a role. Dr. Koshenkov said mitotic rate was not analyzed because it was not regularly included in the pathology report at the time of the review, and that ulceration and Clark’s level IV were factored into the multivariate analysis.

The authors said they had no relevant financial disclosures.

SAN ANTONIO – Patients with thin melanomas and positive deep margins on initial biopsy had the same incidence of sentinel lymph node metastasis as those with thicker melanomas, according to the results of a retrospective analysis of 260 patients with melanoma.

At least one positive sentinel lymph node was detected in 6 of 73 patients (8%) with a melanoma Breslow thickness of less than 0.8 mm and positive deep margins vs. 17 of 187 patients (9%) with a melanoma Breslow thickness of 0.8-2.0 mm, regardless of margin status (P = .82).

Immunohistochemistry was the most common method of identifying positive sentinel nodes in both the thin and thick melanoma groups (5 cases vs. 10 cases, respectively), Dr. Victor Koshenkov said at a symposium sponsored by the Society of Surgical Oncology.

The decision to perform sentinel node biopsy is largely driven by tumor thickness. When the initial biopsy of a thin melanoma shows positive deep margins, many clinicians will treat these cases as potentially thicker melanomas and perform sentinel lymph node (SLN) biopsy. There are few data on the impact of positive deep margins on surgical decision making, prognosis, and outcome, even though positive deep margins are the most common cause of incompletely measured or indeterminate tumor thickness, said Dr. Koshenkov of the department of surgery at Atlantic Health Memorial Hospital in Morristown, N.J.

He presented data from a retrospective analysis of 260 adult patients who underwent wide excision plus SLN biopsy for cutaneous melanoma from January 2004 to May 2010.

Demographics were not statistically different between the two groups, except for tumor site and Clark’s level, he said. In 53% of patients in the thicker melanoma group, the extremities were the primary tumor site vs. 38% in the thin melanoma group (P = .042), while 40% had Clark’s level IV-V vs. 22% in the thin melanoma group (P less than .001).

Multivariate regression analysis revealed that only female gender (P = .046; odds ratio, 2.68) and Clark’s level IV-V (P = .024; OR, 3.54) were significantly associated with an increased risk of positive SLNs. Belonging to the thin melanoma group versus the thicker melanoma group was not significant (P = .66; OR, 1.29) Dr. Koshenkov said.

The presence of residual disease approached, but did not reach, statistical significance (P = .062; OR, 2.60). Residual disease was found in about 20% of both groups. Only 4 of the 73 patients (5.5%) with positive SLNs in the thin melanoma group required further reexcision with wide margins.

Only 1 of the 23 sentinel node–positive patients went on to have additional positive nodes on completion of lymph node dissection, he said.

"Patients with thin melanomas and positive deep margins on initial biopsy have an incidence of SLN metastasis statistically no different than patients with thicker melanomas," Dr. Koshenkov concluded. "Thus, we believe that thin melanomas with positive deep margins should be treated with wide excision and a sentinel lymph node biopsy. Of course, these findings should be tested and verified in larger, multi-institutional databases."

During a discussion of the study, the audience questioned the ability to make almost a practice-changing conclusion based on the small number of patients and the low incidence of positive SLNs in the thicker melanoma group. Dr. Koshenkov replied that the reason the rate of sentinel node positivity was lower than predicted in this group was that a larger proportion of patients had melanomas 0.8-1 mm in depth, rather than 1-2 mm in depth.

Another attendee remarked that before concluding that every patient with a positive deep margin on initial biopsy needs to undergo SLN biopsy, it is important to know how many patients with positive sentinel nodes had a positive deep margin as their only indication or whether factors such as mitotic rate or ulceration played a role. Dr. Koshenkov said mitotic rate was not analyzed because it was not regularly included in the pathology report at the time of the review, and that ulceration and Clark’s level IV were factored into the multivariate analysis.

The authors said they had no relevant financial disclosures.

SAN ANTONIO – Patients with thin melanomas and positive deep margins on initial biopsy had the same incidence of sentinel lymph node metastasis as those with thicker melanomas, according to the results of a retrospective analysis of 260 patients with melanoma.

At least one positive sentinel lymph node was detected in 6 of 73 patients (8%) with a melanoma Breslow thickness of less than 0.8 mm and positive deep margins vs. 17 of 187 patients (9%) with a melanoma Breslow thickness of 0.8-2.0 mm, regardless of margin status (P = .82).

Immunohistochemistry was the most common method of identifying positive sentinel nodes in both the thin and thick melanoma groups (5 cases vs. 10 cases, respectively), Dr. Victor Koshenkov said at a symposium sponsored by the Society of Surgical Oncology.

The decision to perform sentinel node biopsy is largely driven by tumor thickness. When the initial biopsy of a thin melanoma shows positive deep margins, many clinicians will treat these cases as potentially thicker melanomas and perform sentinel lymph node (SLN) biopsy. There are few data on the impact of positive deep margins on surgical decision making, prognosis, and outcome, even though positive deep margins are the most common cause of incompletely measured or indeterminate tumor thickness, said Dr. Koshenkov of the department of surgery at Atlantic Health Memorial Hospital in Morristown, N.J.

He presented data from a retrospective analysis of 260 adult patients who underwent wide excision plus SLN biopsy for cutaneous melanoma from January 2004 to May 2010.

Demographics were not statistically different between the two groups, except for tumor site and Clark’s level, he said. In 53% of patients in the thicker melanoma group, the extremities were the primary tumor site vs. 38% in the thin melanoma group (P = .042), while 40% had Clark’s level IV-V vs. 22% in the thin melanoma group (P less than .001).

Multivariate regression analysis revealed that only female gender (P = .046; odds ratio, 2.68) and Clark’s level IV-V (P = .024; OR, 3.54) were significantly associated with an increased risk of positive SLNs. Belonging to the thin melanoma group versus the thicker melanoma group was not significant (P = .66; OR, 1.29) Dr. Koshenkov said.

The presence of residual disease approached, but did not reach, statistical significance (P = .062; OR, 2.60). Residual disease was found in about 20% of both groups. Only 4 of the 73 patients (5.5%) with positive SLNs in the thin melanoma group required further reexcision with wide margins.

Only 1 of the 23 sentinel node–positive patients went on to have additional positive nodes on completion of lymph node dissection, he said.

"Patients with thin melanomas and positive deep margins on initial biopsy have an incidence of SLN metastasis statistically no different than patients with thicker melanomas," Dr. Koshenkov concluded. "Thus, we believe that thin melanomas with positive deep margins should be treated with wide excision and a sentinel lymph node biopsy. Of course, these findings should be tested and verified in larger, multi-institutional databases."

During a discussion of the study, the audience questioned the ability to make almost a practice-changing conclusion based on the small number of patients and the low incidence of positive SLNs in the thicker melanoma group. Dr. Koshenkov replied that the reason the rate of sentinel node positivity was lower than predicted in this group was that a larger proportion of patients had melanomas 0.8-1 mm in depth, rather than 1-2 mm in depth.

Another attendee remarked that before concluding that every patient with a positive deep margin on initial biopsy needs to undergo SLN biopsy, it is important to know how many patients with positive sentinel nodes had a positive deep margin as their only indication or whether factors such as mitotic rate or ulceration played a role. Dr. Koshenkov said mitotic rate was not analyzed because it was not regularly included in the pathology report at the time of the review, and that ulceration and Clark’s level IV were factored into the multivariate analysis.

The authors said they had no relevant financial disclosures.

SAN ANTONIO – Young, healthy patients with early-stage colon cancer are more likely to be overtreated, whereas older, uninsured patients with higher-risk disease tend to be undertreated, according to an analysis of 236,964 cases.

"Although adherence [to stage-specific treatment guidelines] has increased over the past 5 years, significant variability still exists," Dr. Ryaz B. Chagpar said during a plenary session at a symposium sponsored by the Society of Surgical Oncology.

Treatment guideline adherence has been proposed as a potential measure of the quality of cancer care. Colon cancer guideline adherence is a potentially attractive quality measure since consensus on treatment standards exists among several agencies including the National Comprehensive Cancer Network (NCCN), the American Society for Clinical Oncology, and the National Quality Forum, he said. However, nationwide assessment of current stage-specific colon cancer treatment practices is lacking.

Using the National Cancer Data Base, Dr. Chagpar and his colleagues in the department of surgical oncology at MD Anderson Cancer Center in Houston, identified all patients diagnosed with colon cancer from 2003 to 2007. The database captures about 70% of all annual cancer diagnoses within the United States from more than 1,430 hospitals, and is a joint program of the American College of Surgeons Commission on Cancer and the American Cancer Society.

After excluding hospitals that were only diagnostic, the researchers identified 236,964 patients. The patients were then restaged from pathological variables according to the American Joint Committee on Cancer 6th edition staging manual, and grouped according to whether their treatment was adherent with NCCN guidelines. Of note, stage II disease was stratified into low- and high-risk disease based on the guidelines, with the latter defined as patients with T4 lesions, those with less than a 12-node lymphadenectomy, and tumors categorized as at least grade 3 or resected with positive margins.

Adherence for stage I and low-risk stage II colon cancer was defined as surgical resection. Nonadherence included the recommendation of adjuvant chemotherapy, independent of whether the treatment was actually received (overtreatment), or no adequate surgical resection (undertreatment), Dr. Chagpar said.

For stage II high-risk disease, adherence was defined as the consideration of adjuvant chemotherapy following surgical resection. Overtreatment included the addition of radiation to chemotherapy and undertreatment was surgical resection alone.

Adherence for stage III disease was defined as that for stage II high-risk disease. The only difference for stage IV adherence was the recommendation of chemotherapy, independent of whether surgical resection was performed, he explained.

Patients with stage I colon cancer were significantly more likely to receive guideline-based treatment, at 95.5%, compared with 74% for low-risk stage II, just 27% for high-risk stage II, 64.5% for stage III, and 68% for stage IV (P value less than .0005).

The researchers then performed hierarchical regression modeling that controlled for heterogeneity at both the hospital level and patient level to determine factors associated with adherence.

Interestingly, for stage I and low-risk stage II disease, increasing age as well as increasing Charlson-Deyo Comorbidity Index was associated with a greater likelihood of receiving adherent treatment, whereas for higher-risk disease, older patients as well as those with a greater number of comorbidities were less likely to receive guideline-based treatment, Dr. Chagpar said.

Also, a later year of diagnosis (2007 vs. 2003) was associated with greater likelihood of receiving guideline-based treatment regardless of disease stage. The same was true for having private insurance, with the exception of low-risk stage II disease.

Nonadherence for stage I and low-risk patients was largely attributable to overtreatment in the form of recommendations for adjuvant chemotherapy, particularly in young, healthy patients and those with private insurance, Dr. Chagpar said.

Nonadherence for high-risk stage II, stage III, and stage IV disease was primarily due to undertreatment, particularly for older, uninsured patients and those with a number of preexisting comorbidities.

"Given that guideline-based care, however, does not necessarily translate into improved survival and patient-reported outcomes, the impact of nonadherence on the quality of cancer care needs to be further elucidated," he concluded.

Limitations of the study include variability in the level of evidence used to construct NCCN guidelines; a lack of pathological staging data for 15% of patients; and a lack of data on some factors used to characterize high-risk stage II disease, such as lymphatic vascular invasion and obstruction. In addition, systemic therapy is often underreported in cancer registries, the authors said.

The authors reported no conflicts of interest.

SAN ANTONIO – Young, healthy patients with early-stage colon cancer are more likely to be overtreated, whereas older, uninsured patients with higher-risk disease tend to be undertreated, according to an analysis of 236,964 cases.

"Although adherence [to stage-specific treatment guidelines] has increased over the past 5 years, significant variability still exists," Dr. Ryaz B. Chagpar said during a plenary session at a symposium sponsored by the Society of Surgical Oncology.

Treatment guideline adherence has been proposed as a potential measure of the quality of cancer care. Colon cancer guideline adherence is a potentially attractive quality measure since consensus on treatment standards exists among several agencies including the National Comprehensive Cancer Network (NCCN), the American Society for Clinical Oncology, and the National Quality Forum, he said. However, nationwide assessment of current stage-specific colon cancer treatment practices is lacking.

Using the National Cancer Data Base, Dr. Chagpar and his colleagues in the department of surgical oncology at MD Anderson Cancer Center in Houston, identified all patients diagnosed with colon cancer from 2003 to 2007. The database captures about 70% of all annual cancer diagnoses within the United States from more than 1,430 hospitals, and is a joint program of the American College of Surgeons Commission on Cancer and the American Cancer Society.

After excluding hospitals that were only diagnostic, the researchers identified 236,964 patients. The patients were then restaged from pathological variables according to the American Joint Committee on Cancer 6th edition staging manual, and grouped according to whether their treatment was adherent with NCCN guidelines. Of note, stage II disease was stratified into low- and high-risk disease based on the guidelines, with the latter defined as patients with T4 lesions, those with less than a 12-node lymphadenectomy, and tumors categorized as at least grade 3 or resected with positive margins.

Adherence for stage I and low-risk stage II colon cancer was defined as surgical resection. Nonadherence included the recommendation of adjuvant chemotherapy, independent of whether the treatment was actually received (overtreatment), or no adequate surgical resection (undertreatment), Dr. Chagpar said.

For stage II high-risk disease, adherence was defined as the consideration of adjuvant chemotherapy following surgical resection. Overtreatment included the addition of radiation to chemotherapy and undertreatment was surgical resection alone.

Adherence for stage III disease was defined as that for stage II high-risk disease. The only difference for stage IV adherence was the recommendation of chemotherapy, independent of whether surgical resection was performed, he explained.

Patients with stage I colon cancer were significantly more likely to receive guideline-based treatment, at 95.5%, compared with 74% for low-risk stage II, just 27% for high-risk stage II, 64.5% for stage III, and 68% for stage IV (P value less than .0005).

The researchers then performed hierarchical regression modeling that controlled for heterogeneity at both the hospital level and patient level to determine factors associated with adherence.

Interestingly, for stage I and low-risk stage II disease, increasing age as well as increasing Charlson-Deyo Comorbidity Index was associated with a greater likelihood of receiving adherent treatment, whereas for higher-risk disease, older patients as well as those with a greater number of comorbidities were less likely to receive guideline-based treatment, Dr. Chagpar said.

Also, a later year of diagnosis (2007 vs. 2003) was associated with greater likelihood of receiving guideline-based treatment regardless of disease stage. The same was true for having private insurance, with the exception of low-risk stage II disease.

Nonadherence for stage I and low-risk patients was largely attributable to overtreatment in the form of recommendations for adjuvant chemotherapy, particularly in young, healthy patients and those with private insurance, Dr. Chagpar said.

Nonadherence for high-risk stage II, stage III, and stage IV disease was primarily due to undertreatment, particularly for older, uninsured patients and those with a number of preexisting comorbidities.

"Given that guideline-based care, however, does not necessarily translate into improved survival and patient-reported outcomes, the impact of nonadherence on the quality of cancer care needs to be further elucidated," he concluded.

Limitations of the study include variability in the level of evidence used to construct NCCN guidelines; a lack of pathological staging data for 15% of patients; and a lack of data on some factors used to characterize high-risk stage II disease, such as lymphatic vascular invasion and obstruction. In addition, systemic therapy is often underreported in cancer registries, the authors said.

The authors reported no conflicts of interest.

SAN ANTONIO – Young, healthy patients with early-stage colon cancer are more likely to be overtreated, whereas older, uninsured patients with higher-risk disease tend to be undertreated, according to an analysis of 236,964 cases.

"Although adherence [to stage-specific treatment guidelines] has increased over the past 5 years, significant variability still exists," Dr. Ryaz B. Chagpar said during a plenary session at a symposium sponsored by the Society of Surgical Oncology.

Treatment guideline adherence has been proposed as a potential measure of the quality of cancer care. Colon cancer guideline adherence is a potentially attractive quality measure since consensus on treatment standards exists among several agencies including the National Comprehensive Cancer Network (NCCN), the American Society for Clinical Oncology, and the National Quality Forum, he said. However, nationwide assessment of current stage-specific colon cancer treatment practices is lacking.

Using the National Cancer Data Base, Dr. Chagpar and his colleagues in the department of surgical oncology at MD Anderson Cancer Center in Houston, identified all patients diagnosed with colon cancer from 2003 to 2007. The database captures about 70% of all annual cancer diagnoses within the United States from more than 1,430 hospitals, and is a joint program of the American College of Surgeons Commission on Cancer and the American Cancer Society.

After excluding hospitals that were only diagnostic, the researchers identified 236,964 patients. The patients were then restaged from pathological variables according to the American Joint Committee on Cancer 6th edition staging manual, and grouped according to whether their treatment was adherent with NCCN guidelines. Of note, stage II disease was stratified into low- and high-risk disease based on the guidelines, with the latter defined as patients with T4 lesions, those with less than a 12-node lymphadenectomy, and tumors categorized as at least grade 3 or resected with positive margins.

Adherence for stage I and low-risk stage II colon cancer was defined as surgical resection. Nonadherence included the recommendation of adjuvant chemotherapy, independent of whether the treatment was actually received (overtreatment), or no adequate surgical resection (undertreatment), Dr. Chagpar said.

For stage II high-risk disease, adherence was defined as the consideration of adjuvant chemotherapy following surgical resection. Overtreatment included the addition of radiation to chemotherapy and undertreatment was surgical resection alone.

Adherence for stage III disease was defined as that for stage II high-risk disease. The only difference for stage IV adherence was the recommendation of chemotherapy, independent of whether surgical resection was performed, he explained.

Patients with stage I colon cancer were significantly more likely to receive guideline-based treatment, at 95.5%, compared with 74% for low-risk stage II, just 27% for high-risk stage II, 64.5% for stage III, and 68% for stage IV (P value less than .0005).

The researchers then performed hierarchical regression modeling that controlled for heterogeneity at both the hospital level and patient level to determine factors associated with adherence.

Interestingly, for stage I and low-risk stage II disease, increasing age as well as increasing Charlson-Deyo Comorbidity Index was associated with a greater likelihood of receiving adherent treatment, whereas for higher-risk disease, older patients as well as those with a greater number of comorbidities were less likely to receive guideline-based treatment, Dr. Chagpar said.

Also, a later year of diagnosis (2007 vs. 2003) was associated with greater likelihood of receiving guideline-based treatment regardless of disease stage. The same was true for having private insurance, with the exception of low-risk stage II disease.

Nonadherence for stage I and low-risk patients was largely attributable to overtreatment in the form of recommendations for adjuvant chemotherapy, particularly in young, healthy patients and those with private insurance, Dr. Chagpar said.

Nonadherence for high-risk stage II, stage III, and stage IV disease was primarily due to undertreatment, particularly for older, uninsured patients and those with a number of preexisting comorbidities.

"Given that guideline-based care, however, does not necessarily translate into improved survival and patient-reported outcomes, the impact of nonadherence on the quality of cancer care needs to be further elucidated," he concluded.

Limitations of the study include variability in the level of evidence used to construct NCCN guidelines; a lack of pathological staging data for 15% of patients; and a lack of data on some factors used to characterize high-risk stage II disease, such as lymphatic vascular invasion and obstruction. In addition, systemic therapy is often underreported in cancer registries, the authors said.

The authors reported no conflicts of interest.

SAN ANTONIO – In a large but nonrandomized group of patients with primary melanoma, sentinel node biopsy significantly prolonged disease-free survival, but offered no prolongation of distant metastases free- or melanoma-specific survival.

Researchers at the Melanoma Institute Australia in North Sydney evaluated survival among 5,567 patients who from 1992 to 2008 underwent wide local excision with or without sentinel node biopsy (SNB) for a primary melanoma that was at least 1 mm thick, Clark level IV or V, or had ulceration. Median follow-up was 3.5 years.

Among the 2,803 patients who underwent SNB, 390 had a positive sentinel node (14%), followed by early complete lymph node dissection. Of the 2,413 patients with a negative sentinel node, 88 experienced regional lymph node recurrence (3.6%) and underwent delayed total lymph node dissection. This resulted in a false-negative rate for SNB of 18.4%, Mr. Stijn van der Ploeg, M.Sc., reported.

Among the 2,765 patients who underwent wide local excision with nodal observation using ultrasound, 378 experienced regional lymph node recurrence (13.7%) and underwent delayed total lymph node dissection.

In univariate analysis, patients who underwent SNB had significantly improved disease-free survival and regional lymph node metastases-free survival (both P value less than .001), but no prolongation in distant metastases-free survival (P = .85) or melanoma-specific survival (P = .49), said Mr. van der Ploeg, now a doctoral student at Erasmus Medical Center in Rotterdam, The Netherlands.

When patients were stratified by tumor thickness, melanoma-specific survival significantly improved in SNB patients with tumors 1.2 mm to 3.5 mm thick (P = .01).

Mr. van der Ploeg pointed out that there were significant differences between the two groups. The SNB group had younger patients, more nodular melanomas, and more distant recurrence as the first site of recurrence, while the observation group had thinner primary tumors, more tumors located in the head and neck, and more nodal recurrences as the first site of recurrence.

After adjusting for these and other differences – including gender, age, histological subtype, mitotic rate, Clark level, and ulceration – the researchers observed no significant benefit for SNB vs. observation for melanoma-specific survival among patients in all thickness subgroups analyzed, he said.

Finally, in univariate analysis, early complete lymph node dissection failed to significantly improve distant metastases-free survival or melanoma-specific survival among SNB-positive patients of all thickness subgroups. There was a trend toward improved distant metastases free-survival favoring early vs. late dissection among patients with intermediate-thickness melanoma (P = .060).

"Our study suggests that patients with intermediate-thickness melanomas 1.2 [mm] to 3.5 [mm] are most likely to have therapeutic benefit from undergoing sentinel node biopsy," Mr. van der Ploeg concluded.

He added that the final results of the Multicenter Selective Lymphadenectomy Trial-1 (MSLT-1) are awaited with great interest, to better define melanoma patient subgroups most likely to obtain a survival benefit from SNB.

Interim analyses from MSLT-1 have confirmed that disease-free and distant disease-free survival are improved with SNB among patients with intermediate-thickness melanomas, but the long-running trial has failed to show a definitive overall survival advantage for the procedure.

During a discussion of the Australian study, audience members asked what techniques were used for SNB, remarking that the false-negative rate of 18% is well above the 4% rate reached by many groups today. Mr. van der Ploeg said the false-negative rate has fallen over time with more experience to 15%, and that surgeons use blue dye, but not the 10% rule during lymph node mapping.

The authors reported no disclosures.

SAN ANTONIO – In a large but nonrandomized group of patients with primary melanoma, sentinel node biopsy significantly prolonged disease-free survival, but offered no prolongation of distant metastases free- or melanoma-specific survival.

Researchers at the Melanoma Institute Australia in North Sydney evaluated survival among 5,567 patients who from 1992 to 2008 underwent wide local excision with or without sentinel node biopsy (SNB) for a primary melanoma that was at least 1 mm thick, Clark level IV or V, or had ulceration. Median follow-up was 3.5 years.

Among the 2,803 patients who underwent SNB, 390 had a positive sentinel node (14%), followed by early complete lymph node dissection. Of the 2,413 patients with a negative sentinel node, 88 experienced regional lymph node recurrence (3.6%) and underwent delayed total lymph node dissection. This resulted in a false-negative rate for SNB of 18.4%, Mr. Stijn van der Ploeg, M.Sc., reported.

Among the 2,765 patients who underwent wide local excision with nodal observation using ultrasound, 378 experienced regional lymph node recurrence (13.7%) and underwent delayed total lymph node dissection.

In univariate analysis, patients who underwent SNB had significantly improved disease-free survival and regional lymph node metastases-free survival (both P value less than .001), but no prolongation in distant metastases-free survival (P = .85) or melanoma-specific survival (P = .49), said Mr. van der Ploeg, now a doctoral student at Erasmus Medical Center in Rotterdam, The Netherlands.

When patients were stratified by tumor thickness, melanoma-specific survival significantly improved in SNB patients with tumors 1.2 mm to 3.5 mm thick (P = .01).

Mr. van der Ploeg pointed out that there were significant differences between the two groups. The SNB group had younger patients, more nodular melanomas, and more distant recurrence as the first site of recurrence, while the observation group had thinner primary tumors, more tumors located in the head and neck, and more nodal recurrences as the first site of recurrence.

After adjusting for these and other differences – including gender, age, histological subtype, mitotic rate, Clark level, and ulceration – the researchers observed no significant benefit for SNB vs. observation for melanoma-specific survival among patients in all thickness subgroups analyzed, he said.

Finally, in univariate analysis, early complete lymph node dissection failed to significantly improve distant metastases-free survival or melanoma-specific survival among SNB-positive patients of all thickness subgroups. There was a trend toward improved distant metastases free-survival favoring early vs. late dissection among patients with intermediate-thickness melanoma (P = .060).

"Our study suggests that patients with intermediate-thickness melanomas 1.2 [mm] to 3.5 [mm] are most likely to have therapeutic benefit from undergoing sentinel node biopsy," Mr. van der Ploeg concluded.

He added that the final results of the Multicenter Selective Lymphadenectomy Trial-1 (MSLT-1) are awaited with great interest, to better define melanoma patient subgroups most likely to obtain a survival benefit from SNB.

Interim analyses from MSLT-1 have confirmed that disease-free and distant disease-free survival are improved with SNB among patients with intermediate-thickness melanomas, but the long-running trial has failed to show a definitive overall survival advantage for the procedure.

During a discussion of the Australian study, audience members asked what techniques were used for SNB, remarking that the false-negative rate of 18% is well above the 4% rate reached by many groups today. Mr. van der Ploeg said the false-negative rate has fallen over time with more experience to 15%, and that surgeons use blue dye, but not the 10% rule during lymph node mapping.

The authors reported no disclosures.

SAN ANTONIO – In a large but nonrandomized group of patients with primary melanoma, sentinel node biopsy significantly prolonged disease-free survival, but offered no prolongation of distant metastases free- or melanoma-specific survival.

Researchers at the Melanoma Institute Australia in North Sydney evaluated survival among 5,567 patients who from 1992 to 2008 underwent wide local excision with or without sentinel node biopsy (SNB) for a primary melanoma that was at least 1 mm thick, Clark level IV or V, or had ulceration. Median follow-up was 3.5 years.

Among the 2,803 patients who underwent SNB, 390 had a positive sentinel node (14%), followed by early complete lymph node dissection. Of the 2,413 patients with a negative sentinel node, 88 experienced regional lymph node recurrence (3.6%) and underwent delayed total lymph node dissection. This resulted in a false-negative rate for SNB of 18.4%, Mr. Stijn van der Ploeg, M.Sc., reported.

Among the 2,765 patients who underwent wide local excision with nodal observation using ultrasound, 378 experienced regional lymph node recurrence (13.7%) and underwent delayed total lymph node dissection.

In univariate analysis, patients who underwent SNB had significantly improved disease-free survival and regional lymph node metastases-free survival (both P value less than .001), but no prolongation in distant metastases-free survival (P = .85) or melanoma-specific survival (P = .49), said Mr. van der Ploeg, now a doctoral student at Erasmus Medical Center in Rotterdam, The Netherlands.

When patients were stratified by tumor thickness, melanoma-specific survival significantly improved in SNB patients with tumors 1.2 mm to 3.5 mm thick (P = .01).

Mr. van der Ploeg pointed out that there were significant differences between the two groups. The SNB group had younger patients, more nodular melanomas, and more distant recurrence as the first site of recurrence, while the observation group had thinner primary tumors, more tumors located in the head and neck, and more nodal recurrences as the first site of recurrence.

After adjusting for these and other differences – including gender, age, histological subtype, mitotic rate, Clark level, and ulceration – the researchers observed no significant benefit for SNB vs. observation for melanoma-specific survival among patients in all thickness subgroups analyzed, he said.

Finally, in univariate analysis, early complete lymph node dissection failed to significantly improve distant metastases-free survival or melanoma-specific survival among SNB-positive patients of all thickness subgroups. There was a trend toward improved distant metastases free-survival favoring early vs. late dissection among patients with intermediate-thickness melanoma (P = .060).

"Our study suggests that patients with intermediate-thickness melanomas 1.2 [mm] to 3.5 [mm] are most likely to have therapeutic benefit from undergoing sentinel node biopsy," Mr. van der Ploeg concluded.

He added that the final results of the Multicenter Selective Lymphadenectomy Trial-1 (MSLT-1) are awaited with great interest, to better define melanoma patient subgroups most likely to obtain a survival benefit from SNB.

Interim analyses from MSLT-1 have confirmed that disease-free and distant disease-free survival are improved with SNB among patients with intermediate-thickness melanomas, but the long-running trial has failed to show a definitive overall survival advantage for the procedure.

During a discussion of the Australian study, audience members asked what techniques were used for SNB, remarking that the false-negative rate of 18% is well above the 4% rate reached by many groups today. Mr. van der Ploeg said the false-negative rate has fallen over time with more experience to 15%, and that surgeons use blue dye, but not the 10% rule during lymph node mapping.

The authors reported no disclosures.

SAN ANTONIO – In a large but nonrandomized group of patients with primary melanoma, sentinel node biopsy significantly prolonged disease-free survival, but offered no prolongation of distant metastases free- or melanoma-specific survival.

Researchers at the Melanoma Institute Australia in North Sydney evaluated survival among 5,567 patients who from 1992 to 2008 underwent wide local excision with or without sentinel node biopsy (SNB) for a primary melanoma that was at least 1 mm thick, Clark level IV or V, or had ulceration. Median follow-up was 3.5 years.

Among the 2,803 patients who underwent SNB, 390 had a positive sentinel node (14%), followed by early complete lymph node dissection. Of the 2,413 patients with a negative sentinel node, 88 experienced regional lymph node recurrence (3.6%) and underwent delayed total lymph node dissection. This resulted in a false-negative rate for SNB of 18.4%, Mr. Stijn van der Ploeg, M.Sc., reported.

Among the 2,765 patients who underwent wide local excision with nodal observation using ultrasound, 378 experienced regional lymph node recurrence (13.7%) and underwent delayed total lymph node dissection.

In univariate analysis, patients who underwent SNB had significantly improved disease-free survival and regional lymph node metastases-free survival (both P value less than .001), but no prolongation in distant metastases-free survival (P = .85) or melanoma-specific survival (P = .49), said Mr. van der Ploeg, now a doctoral student at Erasmus Medical Center in Rotterdam, The Netherlands.

When patients were stratified by tumor thickness, melanoma-specific survival significantly improved in SNB patients with tumors 1.2 mm to 3.5 mm thick (P = .01).

Mr. van der Ploeg pointed out that there were significant differences between the two groups. The SNB group had younger patients, more nodular melanomas, and more distant recurrence as the first site of recurrence, while the observation group had thinner primary tumors, more tumors located in the head and neck, and more nodal recurrences as the first site of recurrence.

After adjusting for these and other differences – including gender, age, histological subtype, mitotic rate, Clark level, and ulceration – the researchers observed no significant benefit for SNB vs. observation for melanoma-specific survival among patients in all thickness subgroups analyzed, he said.

Finally, in univariate analysis, early complete lymph node dissection failed to significantly improve distant metastases-free survival or melanoma-specific survival among SNB-positive patients of all thickness subgroups. There was a trend toward improved distant metastases free-survival favoring early vs. late dissection among patients with intermediate-thickness melanoma (P = .060).

"Our study suggests that patients with intermediate-thickness melanomas 1.2 [mm] to 3.5 [mm] are most likely to have therapeutic benefit from undergoing sentinel node biopsy," Mr. van der Ploeg concluded.

He added that the final results of the Multicenter Selective Lymphadenectomy Trial-1 (MSLT-1) are awaited with great interest, to better define melanoma patient subgroups most likely to obtain a survival benefit from SNB.

Interim analyses from MSLT-1 have confirmed that disease-free and distant disease-free survival are improved with SNB among patients with intermediate-thickness melanomas, but the long-running trial has failed to show a definitive overall survival advantage for the procedure.

During a discussion of the Australian study, audience members asked what techniques were used for SNB, remarking that the false-negative rate of 18% is well above the 4% rate reached by many groups today. Mr. van der Ploeg said the false-negative rate has fallen over time with more experience to 15%, and that surgeons use blue dye, but not the 10% rule during lymph node mapping.

The authors reported no disclosures.

SAN ANTONIO – In a large but nonrandomized group of patients with primary melanoma, sentinel node biopsy significantly prolonged disease-free survival, but offered no prolongation of distant metastases free- or melanoma-specific survival.

Researchers at the Melanoma Institute Australia in North Sydney evaluated survival among 5,567 patients who from 1992 to 2008 underwent wide local excision with or without sentinel node biopsy (SNB) for a primary melanoma that was at least 1 mm thick, Clark level IV or V, or had ulceration. Median follow-up was 3.5 years.

Among the 2,803 patients who underwent SNB, 390 had a positive sentinel node (14%), followed by early complete lymph node dissection. Of the 2,413 patients with a negative sentinel node, 88 experienced regional lymph node recurrence (3.6%) and underwent delayed total lymph node dissection. This resulted in a false-negative rate for SNB of 18.4%, Mr. Stijn van der Ploeg, M.Sc., reported.

Among the 2,765 patients who underwent wide local excision with nodal observation using ultrasound, 378 experienced regional lymph node recurrence (13.7%) and underwent delayed total lymph node dissection.

In univariate analysis, patients who underwent SNB had significantly improved disease-free survival and regional lymph node metastases-free survival (both P value less than .001), but no prolongation in distant metastases-free survival (P = .85) or melanoma-specific survival (P = .49), said Mr. van der Ploeg, now a doctoral student at Erasmus Medical Center in Rotterdam, The Netherlands.

When patients were stratified by tumor thickness, melanoma-specific survival significantly improved in SNB patients with tumors 1.2 mm to 3.5 mm thick (P = .01).

Mr. van der Ploeg pointed out that there were significant differences between the two groups. The SNB group had younger patients, more nodular melanomas, and more distant recurrence as the first site of recurrence, while the observation group had thinner primary tumors, more tumors located in the head and neck, and more nodal recurrences as the first site of recurrence.

After adjusting for these and other differences – including gender, age, histological subtype, mitotic rate, Clark level, and ulceration – the researchers observed no significant benefit for SNB vs. observation for melanoma-specific survival among patients in all thickness subgroups analyzed, he said.

Finally, in univariate analysis, early complete lymph node dissection failed to significantly improve distant metastases-free survival or melanoma-specific survival among SNB-positive patients of all thickness subgroups. There was a trend toward improved distant metastases free-survival favoring early vs. late dissection among patients with intermediate-thickness melanoma (P = .060).

"Our study suggests that patients with intermediate-thickness melanomas 1.2 [mm] to 3.5 [mm] are most likely to have therapeutic benefit from undergoing sentinel node biopsy," Mr. van der Ploeg concluded.

He added that the final results of the Multicenter Selective Lymphadenectomy Trial-1 (MSLT-1) are awaited with great interest, to better define melanoma patient subgroups most likely to obtain a survival benefit from SNB.

Interim analyses from MSLT-1 have confirmed that disease-free and distant disease-free survival are improved with SNB among patients with intermediate-thickness melanomas, but the long-running trial has failed to show a definitive overall survival advantage for the procedure.

During a discussion of the Australian study, audience members asked what techniques were used for SNB, remarking that the false-negative rate of 18% is well above the 4% rate reached by many groups today. Mr. van der Ploeg said the false-negative rate has fallen over time with more experience to 15%, and that surgeons use blue dye, but not the 10% rule during lymph node mapping.

The authors reported no disclosures.

SAN ANTONIO – In a large but nonrandomized group of patients with primary melanoma, sentinel node biopsy significantly prolonged disease-free survival, but offered no prolongation of distant metastases free- or melanoma-specific survival.

Researchers at the Melanoma Institute Australia in North Sydney evaluated survival among 5,567 patients who from 1992 to 2008 underwent wide local excision with or without sentinel node biopsy (SNB) for a primary melanoma that was at least 1 mm thick, Clark level IV or V, or had ulceration. Median follow-up was 3.5 years.

Among the 2,803 patients who underwent SNB, 390 had a positive sentinel node (14%), followed by early complete lymph node dissection. Of the 2,413 patients with a negative sentinel node, 88 experienced regional lymph node recurrence (3.6%) and underwent delayed total lymph node dissection. This resulted in a false-negative rate for SNB of 18.4%, Mr. Stijn van der Ploeg, M.Sc., reported.

Among the 2,765 patients who underwent wide local excision with nodal observation using ultrasound, 378 experienced regional lymph node recurrence (13.7%) and underwent delayed total lymph node dissection.

In univariate analysis, patients who underwent SNB had significantly improved disease-free survival and regional lymph node metastases-free survival (both P value less than .001), but no prolongation in distant metastases-free survival (P = .85) or melanoma-specific survival (P = .49), said Mr. van der Ploeg, now a doctoral student at Erasmus Medical Center in Rotterdam, The Netherlands.

When patients were stratified by tumor thickness, melanoma-specific survival significantly improved in SNB patients with tumors 1.2 mm to 3.5 mm thick (P = .01).

Mr. van der Ploeg pointed out that there were significant differences between the two groups. The SNB group had younger patients, more nodular melanomas, and more distant recurrence as the first site of recurrence, while the observation group had thinner primary tumors, more tumors located in the head and neck, and more nodal recurrences as the first site of recurrence.

After adjusting for these and other differences – including gender, age, histological subtype, mitotic rate, Clark level, and ulceration – the researchers observed no significant benefit for SNB vs. observation for melanoma-specific survival among patients in all thickness subgroups analyzed, he said.

Finally, in univariate analysis, early complete lymph node dissection failed to significantly improve distant metastases-free survival or melanoma-specific survival among SNB-positive patients of all thickness subgroups. There was a trend toward improved distant metastases free-survival favoring early vs. late dissection among patients with intermediate-thickness melanoma (P = .060).

"Our study suggests that patients with intermediate-thickness melanomas 1.2 [mm] to 3.5 [mm] are most likely to have therapeutic benefit from undergoing sentinel node biopsy," Mr. van der Ploeg concluded.

He added that the final results of the Multicenter Selective Lymphadenectomy Trial-1 (MSLT-1) are awaited with great interest, to better define melanoma patient subgroups most likely to obtain a survival benefit from SNB.

Interim analyses from MSLT-1 have confirmed that disease-free and distant disease-free survival are improved with SNB among patients with intermediate-thickness melanomas, but the long-running trial has failed to show a definitive overall survival advantage for the procedure.

During a discussion of the Australian study, audience members asked what techniques were used for SNB, remarking that the false-negative rate of 18% is well above the 4% rate reached by many groups today. Mr. van der Ploeg said the false-negative rate has fallen over time with more experience to 15%, and that surgeons use blue dye, but not the 10% rule during lymph node mapping.

The authors reported no disclosures.

SAN ANTONIO – In a large but nonrandomized group of patients with primary melanoma, sentinel node biopsy significantly prolonged disease-free survival, but offered no prolongation of distant metastases free- or melanoma-specific survival.

Researchers at the Melanoma Institute Australia in North Sydney evaluated survival among 5,567 patients who from 1992 to 2008 underwent wide local excision with or without sentinel node biopsy (SNB) for a primary melanoma that was at least 1 mm thick, Clark level IV or V, or had ulceration. Median follow-up was 3.5 years.

Among the 2,803 patients who underwent SNB, 390 had a positive sentinel node (14%), followed by early complete lymph node dissection. Of the 2,413 patients with a negative sentinel node, 88 experienced regional lymph node recurrence (3.6%) and underwent delayed total lymph node dissection. This resulted in a false-negative rate for SNB of 18.4%, Mr. Stijn van der Ploeg, M.Sc., reported.

Among the 2,765 patients who underwent wide local excision with nodal observation using ultrasound, 378 experienced regional lymph node recurrence (13.7%) and underwent delayed total lymph node dissection.

In univariate analysis, patients who underwent SNB had significantly improved disease-free survival and regional lymph node metastases-free survival (both P value less than .001), but no prolongation in distant metastases-free survival (P = .85) or melanoma-specific survival (P = .49), said Mr. van der Ploeg, now a doctoral student at Erasmus Medical Center in Rotterdam, The Netherlands.

When patients were stratified by tumor thickness, melanoma-specific survival significantly improved in SNB patients with tumors 1.2 mm to 3.5 mm thick (P = .01).

Mr. van der Ploeg pointed out that there were significant differences between the two groups. The SNB group had younger patients, more nodular melanomas, and more distant recurrence as the first site of recurrence, while the observation group had thinner primary tumors, more tumors located in the head and neck, and more nodal recurrences as the first site of recurrence.

After adjusting for these and other differences – including gender, age, histological subtype, mitotic rate, Clark level, and ulceration – the researchers observed no significant benefit for SNB vs. observation for melanoma-specific survival among patients in all thickness subgroups analyzed, he said.

Finally, in univariate analysis, early complete lymph node dissection failed to significantly improve distant metastases-free survival or melanoma-specific survival among SNB-positive patients of all thickness subgroups. There was a trend toward improved distant metastases free-survival favoring early vs. late dissection among patients with intermediate-thickness melanoma (P = .060).

"Our study suggests that patients with intermediate-thickness melanomas 1.2 [mm] to 3.5 [mm] are most likely to have therapeutic benefit from undergoing sentinel node biopsy," Mr. van der Ploeg concluded.

He added that the final results of the Multicenter Selective Lymphadenectomy Trial-1 (MSLT-1) are awaited with great interest, to better define melanoma patient subgroups most likely to obtain a survival benefit from SNB.

Interim analyses from MSLT-1 have confirmed that disease-free and distant disease-free survival are improved with SNB among patients with intermediate-thickness melanomas, but the long-running trial has failed to show a definitive overall survival advantage for the procedure.

During a discussion of the Australian study, audience members asked what techniques were used for SNB, remarking that the false-negative rate of 18% is well above the 4% rate reached by many groups today. Mr. van der Ploeg said the false-negative rate has fallen over time with more experience to 15%, and that surgeons use blue dye, but not the 10% rule during lymph node mapping.

The authors reported no disclosures.

SAN ANTONIO – In a large but nonrandomized group of patients with primary melanoma, sentinel node biopsy significantly prolonged disease-free survival, but offered no prolongation of distant metastases free- or melanoma-specific survival.

Researchers at the Melanoma Institute Australia in North Sydney evaluated survival among 5,567 patients who from 1992 to 2008 underwent wide local excision with or without sentinel node biopsy (SNB) for a primary melanoma that was at least 1 mm thick, Clark level IV or V, or had ulceration. Median follow-up was 3.5 years.

Among the 2,803 patients who underwent SNB, 390 had a positive sentinel node (14%), followed by early complete lymph node dissection. Of the 2,413 patients with a negative sentinel node, 88 experienced regional lymph node recurrence (3.6%) and underwent delayed total lymph node dissection. This resulted in a false-negative rate for SNB of 18.4%, Mr. Stijn van der Ploeg, M.Sc., reported.

Among the 2,765 patients who underwent wide local excision with nodal observation using ultrasound, 378 experienced regional lymph node recurrence (13.7%) and underwent delayed total lymph node dissection.

In univariate analysis, patients who underwent SNB had significantly improved disease-free survival and regional lymph node metastases-free survival (both P value less than .001), but no prolongation in distant metastases-free survival (P = .85) or melanoma-specific survival (P = .49), said Mr. van der Ploeg, now a doctoral student at Erasmus Medical Center in Rotterdam, The Netherlands.

When patients were stratified by tumor thickness, melanoma-specific survival significantly improved in SNB patients with tumors 1.2 mm to 3.5 mm thick (P = .01).

Mr. van der Ploeg pointed out that there were significant differences between the two groups. The SNB group had younger patients, more nodular melanomas, and more distant recurrence as the first site of recurrence, while the observation group had thinner primary tumors, more tumors located in the head and neck, and more nodal recurrences as the first site of recurrence.

After adjusting for these and other differences – including gender, age, histological subtype, mitotic rate, Clark level, and ulceration – the researchers observed no significant benefit for SNB vs. observation for melanoma-specific survival among patients in all thickness subgroups analyzed, he said.

Finally, in univariate analysis, early complete lymph node dissection failed to significantly improve distant metastases-free survival or melanoma-specific survival among SNB-positive patients of all thickness subgroups. There was a trend toward improved distant metastases free-survival favoring early vs. late dissection among patients with intermediate-thickness melanoma (P = .060).

"Our study suggests that patients with intermediate-thickness melanomas 1.2 [mm] to 3.5 [mm] are most likely to have therapeutic benefit from undergoing sentinel node biopsy," Mr. van der Ploeg concluded.

He added that the final results of the Multicenter Selective Lymphadenectomy Trial-1 (MSLT-1) are awaited with great interest, to better define melanoma patient subgroups most likely to obtain a survival benefit from SNB.

Interim analyses from MSLT-1 have confirmed that disease-free and distant disease-free survival are improved with SNB among patients with intermediate-thickness melanomas, but the long-running trial has failed to show a definitive overall survival advantage for the procedure.

During a discussion of the Australian study, audience members asked what techniques were used for SNB, remarking that the false-negative rate of 18% is well above the 4% rate reached by many groups today. Mr. van der Ploeg said the false-negative rate has fallen over time with more experience to 15%, and that surgeons use blue dye, but not the 10% rule during lymph node mapping.

The authors reported no disclosures.

SAN ANTONIO – In a large but nonrandomized group of patients with primary melanoma, sentinel node biopsy significantly prolonged disease-free survival, but offered no prolongation of distant metastases free- or melanoma-specific survival.

Researchers at the Melanoma Institute Australia in North Sydney evaluated survival among 5,567 patients who from 1992 to 2008 underwent wide local excision with or without sentinel node biopsy (SNB) for a primary melanoma that was at least 1 mm thick, Clark level IV or V, or had ulceration. Median follow-up was 3.5 years.

Among the 2,803 patients who underwent SNB, 390 had a positive sentinel node (14%), followed by early complete lymph node dissection. Of the 2,413 patients with a negative sentinel node, 88 experienced regional lymph node recurrence (3.6%) and underwent delayed total lymph node dissection. This resulted in a false-negative rate for SNB of 18.4%, Mr. Stijn van der Ploeg, M.Sc., reported.

Among the 2,765 patients who underwent wide local excision with nodal observation using ultrasound, 378 experienced regional lymph node recurrence (13.7%) and underwent delayed total lymph node dissection.

In univariate analysis, patients who underwent SNB had significantly improved disease-free survival and regional lymph node metastases-free survival (both P value less than .001), but no prolongation in distant metastases-free survival (P = .85) or melanoma-specific survival (P = .49), said Mr. van der Ploeg, now a doctoral student at Erasmus Medical Center in Rotterdam, The Netherlands.

When patients were stratified by tumor thickness, melanoma-specific survival significantly improved in SNB patients with tumors 1.2 mm to 3.5 mm thick (P = .01).

Mr. van der Ploeg pointed out that there were significant differences between the two groups. The SNB group had younger patients, more nodular melanomas, and more distant recurrence as the first site of recurrence, while the observation group had thinner primary tumors, more tumors located in the head and neck, and more nodal recurrences as the first site of recurrence.

After adjusting for these and other differences – including gender, age, histological subtype, mitotic rate, Clark level, and ulceration – the researchers observed no significant benefit for SNB vs. observation for melanoma-specific survival among patients in all thickness subgroups analyzed, he said.

Finally, in univariate analysis, early complete lymph node dissection failed to significantly improve distant metastases-free survival or melanoma-specific survival among SNB-positive patients of all thickness subgroups. There was a trend toward improved distant metastases free-survival favoring early vs. late dissection among patients with intermediate-thickness melanoma (P = .060).

"Our study suggests that patients with intermediate-thickness melanomas 1.2 [mm] to 3.5 [mm] are most likely to have therapeutic benefit from undergoing sentinel node biopsy," Mr. van der Ploeg concluded.

He added that the final results of the Multicenter Selective Lymphadenectomy Trial-1 (MSLT-1) are awaited with great interest, to better define melanoma patient subgroups most likely to obtain a survival benefit from SNB.

Interim analyses from MSLT-1 have confirmed that disease-free and distant disease-free survival are improved with SNB among patients with intermediate-thickness melanomas, but the long-running trial has failed to show a definitive overall survival advantage for the procedure.

During a discussion of the Australian study, audience members asked what techniques were used for SNB, remarking that the false-negative rate of 18% is well above the 4% rate reached by many groups today. Mr. van der Ploeg said the false-negative rate has fallen over time with more experience to 15%, and that surgeons use blue dye, but not the 10% rule during lymph node mapping.

The authors reported no disclosures.