Can younger postmenopausal women with low-risk BC skip radiation?

SAN ANTONIO — Women 65-70 years old are often offered the option of skipping radiation after lumpectomy for hormone receptor–positive early-stage breast cancer and moving straight to endocrine therapy.

The recurrence rate with and without radiation is well known so women can be counseled accurately about their options. For some, the 10% risk of recurrence at 10 years without radiation seems reasonable, for others it does not.

Omitting radiation for older postmenopausal women is “very reasonable to offer so long as they are willing to accept the risk,” said Reshma Jagsi, MD, chief of radiation oncology at Emory University, Atlanta.

The option, however, isn’t generally offered to postmenopausal women younger than 65 years old because their risk from skipping adjuvant radiation isn’t known, but that’s about to change.

Several teams are investigating the issue, including one led by Dr. Jagsi, who presented her and her colleagues’ latest results at the San Antonio Breast Cancer Symposium.

In the single-arm IDEA [Individualized Decisions for Endocrine therapy Alone] study, 200 women 50-69 years old with pT1N0 unifocal hormone receptor–positive, HER2-negative invasive breast cancer agreed to the approach when it was offered to them following lumpectomy with sentinel lymph node biopsy. The mean tumor size was 10 mm with margins of at least 2 mm.

The women were at low risk for recurrence, with recurrence risk scores no higher than 18 points on the Oncotype DX 21-gene assay; the mean score was 11 points.

Radiation would have been the usual next step after lumpectomy, but instead the patients went directly to endocrine therapy for 5 years, with adherence above 80%.

At 5 years, the results are “promising,” Dr. Jagsi said at the meeting. Overall and breast cancer–specific survival were both 100%, and the recurrence rate was just 1%, with two recurrences before the 5-year point. The women were a mean of 62 years old.

A similar single-arm trial, LUMINA, recently reported comparable results.

Dr. Jagsi called the findings of the studies “reassuring,” but cautioned that it will be a while before younger postmenopausal women can be offered radiation-free treatment like their older peers.

Even though the results suggest “that this might well be a really good idea,” longer follow-up and randomized data are needed “before we change the standard of care,” she said.

Of concern, for instance, is that there were six additional recurrences in the IDEA study past the 5-year mark, for a total of three recurrences among the 60 women 50-59 years old (5%) and five among the 140 women 60-69 years old (3.6%). Five of the recurrent cases were adherent to endocrine therapy.

Also, so few women in IDEA have passed the 5-year mark that “we can’t [conclude] anything” about long-term relapse risks, Dr. Jagsi said. Besides that, skipping radiation for such women at this point is “not reasonable,” Dr. Jagsi added.

Carlos Arteaga, MD, director of the UT Southwestern Simmons Cancer Center, Dallas, agreed.

“I think we have to wait. We have randomized studies that will test this in a formal way. Be that as it may, this provides the basis for a conversation physicians can have with patients because this could be an option” at some point, said Dr. Arteaga, who moderated Dr. Jagsi’s presentation.

“This is a big step in trying not to do too much for patients who don’t need it,” Virginia Kaklamani, MD, leader of the breast cancer program at UT Health San Antonio, said in an interview.

IDEA was published in the Journal of Clinical Oncology to coincide with Dr. Jagsi’s presentation.

The study was funded by the Susan G. Komen Breast Cancer Foundation and the University of Michigan Rogel Cancer Center. Dr. Jagsi has stock in Equity Quotient and research support form Genentech. Disclosure information for Arteaga was not available. Dr. Kaklamani has extensive industry ties, including being a speaker for Pfizer, Genentech, Novartis, and AstraZeneca.

SAN ANTONIO — Women 65-70 years old are often offered the option of skipping radiation after lumpectomy for hormone receptor–positive early-stage breast cancer and moving straight to endocrine therapy.

The recurrence rate with and without radiation is well known so women can be counseled accurately about their options. For some, the 10% risk of recurrence at 10 years without radiation seems reasonable, for others it does not.

Omitting radiation for older postmenopausal women is “very reasonable to offer so long as they are willing to accept the risk,” said Reshma Jagsi, MD, chief of radiation oncology at Emory University, Atlanta.

The option, however, isn’t generally offered to postmenopausal women younger than 65 years old because their risk from skipping adjuvant radiation isn’t known, but that’s about to change.

Several teams are investigating the issue, including one led by Dr. Jagsi, who presented her and her colleagues’ latest results at the San Antonio Breast Cancer Symposium.

In the single-arm IDEA [Individualized Decisions for Endocrine therapy Alone] study, 200 women 50-69 years old with pT1N0 unifocal hormone receptor–positive, HER2-negative invasive breast cancer agreed to the approach when it was offered to them following lumpectomy with sentinel lymph node biopsy. The mean tumor size was 10 mm with margins of at least 2 mm.

The women were at low risk for recurrence, with recurrence risk scores no higher than 18 points on the Oncotype DX 21-gene assay; the mean score was 11 points.

Radiation would have been the usual next step after lumpectomy, but instead the patients went directly to endocrine therapy for 5 years, with adherence above 80%.

At 5 years, the results are “promising,” Dr. Jagsi said at the meeting. Overall and breast cancer–specific survival were both 100%, and the recurrence rate was just 1%, with two recurrences before the 5-year point. The women were a mean of 62 years old.

A similar single-arm trial, LUMINA, recently reported comparable results.

Dr. Jagsi called the findings of the studies “reassuring,” but cautioned that it will be a while before younger postmenopausal women can be offered radiation-free treatment like their older peers.

Even though the results suggest “that this might well be a really good idea,” longer follow-up and randomized data are needed “before we change the standard of care,” she said.

Of concern, for instance, is that there were six additional recurrences in the IDEA study past the 5-year mark, for a total of three recurrences among the 60 women 50-59 years old (5%) and five among the 140 women 60-69 years old (3.6%). Five of the recurrent cases were adherent to endocrine therapy.

Also, so few women in IDEA have passed the 5-year mark that “we can’t [conclude] anything” about long-term relapse risks, Dr. Jagsi said. Besides that, skipping radiation for such women at this point is “not reasonable,” Dr. Jagsi added.

Carlos Arteaga, MD, director of the UT Southwestern Simmons Cancer Center, Dallas, agreed.

“I think we have to wait. We have randomized studies that will test this in a formal way. Be that as it may, this provides the basis for a conversation physicians can have with patients because this could be an option” at some point, said Dr. Arteaga, who moderated Dr. Jagsi’s presentation.

“This is a big step in trying not to do too much for patients who don’t need it,” Virginia Kaklamani, MD, leader of the breast cancer program at UT Health San Antonio, said in an interview.

IDEA was published in the Journal of Clinical Oncology to coincide with Dr. Jagsi’s presentation.

The study was funded by the Susan G. Komen Breast Cancer Foundation and the University of Michigan Rogel Cancer Center. Dr. Jagsi has stock in Equity Quotient and research support form Genentech. Disclosure information for Arteaga was not available. Dr. Kaklamani has extensive industry ties, including being a speaker for Pfizer, Genentech, Novartis, and AstraZeneca.

SAN ANTONIO — Women 65-70 years old are often offered the option of skipping radiation after lumpectomy for hormone receptor–positive early-stage breast cancer and moving straight to endocrine therapy.

The recurrence rate with and without radiation is well known so women can be counseled accurately about their options. For some, the 10% risk of recurrence at 10 years without radiation seems reasonable, for others it does not.

Omitting radiation for older postmenopausal women is “very reasonable to offer so long as they are willing to accept the risk,” said Reshma Jagsi, MD, chief of radiation oncology at Emory University, Atlanta.

The option, however, isn’t generally offered to postmenopausal women younger than 65 years old because their risk from skipping adjuvant radiation isn’t known, but that’s about to change.

Several teams are investigating the issue, including one led by Dr. Jagsi, who presented her and her colleagues’ latest results at the San Antonio Breast Cancer Symposium.

In the single-arm IDEA [Individualized Decisions for Endocrine therapy Alone] study, 200 women 50-69 years old with pT1N0 unifocal hormone receptor–positive, HER2-negative invasive breast cancer agreed to the approach when it was offered to them following lumpectomy with sentinel lymph node biopsy. The mean tumor size was 10 mm with margins of at least 2 mm.

The women were at low risk for recurrence, with recurrence risk scores no higher than 18 points on the Oncotype DX 21-gene assay; the mean score was 11 points.

Radiation would have been the usual next step after lumpectomy, but instead the patients went directly to endocrine therapy for 5 years, with adherence above 80%.

At 5 years, the results are “promising,” Dr. Jagsi said at the meeting. Overall and breast cancer–specific survival were both 100%, and the recurrence rate was just 1%, with two recurrences before the 5-year point. The women were a mean of 62 years old.

A similar single-arm trial, LUMINA, recently reported comparable results.

Dr. Jagsi called the findings of the studies “reassuring,” but cautioned that it will be a while before younger postmenopausal women can be offered radiation-free treatment like their older peers.

Even though the results suggest “that this might well be a really good idea,” longer follow-up and randomized data are needed “before we change the standard of care,” she said.

Of concern, for instance, is that there were six additional recurrences in the IDEA study past the 5-year mark, for a total of three recurrences among the 60 women 50-59 years old (5%) and five among the 140 women 60-69 years old (3.6%). Five of the recurrent cases were adherent to endocrine therapy.

Also, so few women in IDEA have passed the 5-year mark that “we can’t [conclude] anything” about long-term relapse risks, Dr. Jagsi said. Besides that, skipping radiation for such women at this point is “not reasonable,” Dr. Jagsi added.

Carlos Arteaga, MD, director of the UT Southwestern Simmons Cancer Center, Dallas, agreed.

“I think we have to wait. We have randomized studies that will test this in a formal way. Be that as it may, this provides the basis for a conversation physicians can have with patients because this could be an option” at some point, said Dr. Arteaga, who moderated Dr. Jagsi’s presentation.

“This is a big step in trying not to do too much for patients who don’t need it,” Virginia Kaklamani, MD, leader of the breast cancer program at UT Health San Antonio, said in an interview.

IDEA was published in the Journal of Clinical Oncology to coincide with Dr. Jagsi’s presentation.

The study was funded by the Susan G. Komen Breast Cancer Foundation and the University of Michigan Rogel Cancer Center. Dr. Jagsi has stock in Equity Quotient and research support form Genentech. Disclosure information for Arteaga was not available. Dr. Kaklamani has extensive industry ties, including being a speaker for Pfizer, Genentech, Novartis, and AstraZeneca.