Phototherapy has lasting benefit in low-risk prostate cancer

 

SAN FRANCISCO – In men with low-risk prostate cancer, vascular-targeted phototherapy (VTP) led to a significant reduction in subsequent conversions to radiation therapy or prostatectomy, compared with patients who underwent active surveillance. The latest results come at 4 years of follow-up, and confirm a reduction of risk seen in the original study at 2 years post treatment.

The new analysis was presented by Inderbir Gill, MD, in a late-breaking abstract session at the annual meeting of the American Urological Association.

About half of men with low-risk prostate cancer start out with active surveillance, but 25%-60% of them will go on to radical therapy (RT) within the next 5-10 years. Put another way, about 70% of men with low-risk prostate cancer will undergo RT within a decade. This protocol is generally effective, but it comes at a cost: Sixty-six percent of men undergoing radiotherapy and 82% of men undergoing prostatectomy experience incontinence, and 4% and 20%, respectively, experience erectile dysfunction at 2 years.

That adds up to an unmet clinical need: Patients with low-risk prostate cancer would be well served by an alternative therapy that cuts the risk of RT. VTP, along with alternatives cryoablation and high-intensity ultrasound, were developed to meet that need.

The original, phase 3 trial enrolled 413 men at 47 centers in Europe. Participants could have one cancer core that was free of Gleason patterns 4 or 5 as long as its length was between 3 and 5 mm. The study also included men with two or three positive cores, as long as the length was less than 5 mm, but they were excluded if they had Gleason patterns of 4 or 5.The participants were randomized to active surveillance or VTP, which consisted of 4 mg/kg padeliporfin delivered intravenously. Optical fibers inserted into the prostate to target the treatment zone were activated by laser light.

In the VTP group, 185 men completed 24 months of follow-up, as did 174 in the active surveillance group. Overall, 69% of the participants achieved follow-up at 3 years, and 64% at 4 years. At 2 years, 6% of men in the VTP group went on to undergo RT, compared with 29% in the surveillance group (P less than .0001). There were no significant differences between the two groups with respect to incontinence or erectile dysfunction.

In the extension study, similar patterns were seen at 3 and 4 years. At 4 years, 53% of men in the active surveillance group had converted to RT, compared with 24% in the treatment group (hazard ratio, 0.31; 95% confidence interval, 0.21-0.45). The absolute difference in risk for conversion to RT between the two groups was 3% at year 1, 26% at year 2, 30% at year 3, and 29% at year 4.

 

“It’s more of the same. Essentially there was about a 25% reduction in risk of conversion to radical treatment, and that benefit is maintained,” said Dr. Gill, professor and chair of urology at the University of Southern California, Los Angeles.

As expected, survival rates were similar at 4 years. In both groups, 99% were metastasis free, and cancer-specific survival was 100% in both. Overall survival was 98% in the VTP group, and 99% in the active surveillance group.

Currently, in very-low-risk patients, active surveillance is recommended and generally accepted. But many low-risk patients choose RT, putting them at risk for impotency and incontinence. “With this treatment, if you can maintain a 25% reduction in crossover treatment, then more men with low-risk prostate cancer are going to be spared radical treatment than if you were just doing active surveillance. And if you don’t get radical therapy, then your long-term quality of life is better,” said Dr. Gill.

VTP does lead to a small increase in risk of impotency and in incontinence in the short term, but patients tend to recover, and by 2 years, there is no significant difference between the groups.

Cryoablation and high-intensity focused ultrasound are also available. Those are effective, but they seem to have a higher profile of incontinence, impotency, and urethral injury, although they haven’t been directly compared to VTP, so comparing their side effect profiles “is literally comparing apples to oranges,” Dr. Gill said.

 

SAN FRANCISCO – In men with low-risk prostate cancer, vascular-targeted phototherapy (VTP) led to a significant reduction in subsequent conversions to radiation therapy or prostatectomy, compared with patients who underwent active surveillance. The latest results come at 4 years of follow-up, and confirm a reduction of risk seen in the original study at 2 years post treatment.

The new analysis was presented by Inderbir Gill, MD, in a late-breaking abstract session at the annual meeting of the American Urological Association.

About half of men with low-risk prostate cancer start out with active surveillance, but 25%-60% of them will go on to radical therapy (RT) within the next 5-10 years. Put another way, about 70% of men with low-risk prostate cancer will undergo RT within a decade. This protocol is generally effective, but it comes at a cost: Sixty-six percent of men undergoing radiotherapy and 82% of men undergoing prostatectomy experience incontinence, and 4% and 20%, respectively, experience erectile dysfunction at 2 years.

That adds up to an unmet clinical need: Patients with low-risk prostate cancer would be well served by an alternative therapy that cuts the risk of RT. VTP, along with alternatives cryoablation and high-intensity ultrasound, were developed to meet that need.

The original, phase 3 trial enrolled 413 men at 47 centers in Europe. Participants could have one cancer core that was free of Gleason patterns 4 or 5 as long as its length was between 3 and 5 mm. The study also included men with two or three positive cores, as long as the length was less than 5 mm, but they were excluded if they had Gleason patterns of 4 or 5.The participants were randomized to active surveillance or VTP, which consisted of 4 mg/kg padeliporfin delivered intravenously. Optical fibers inserted into the prostate to target the treatment zone were activated by laser light.

In the VTP group, 185 men completed 24 months of follow-up, as did 174 in the active surveillance group. Overall, 69% of the participants achieved follow-up at 3 years, and 64% at 4 years. At 2 years, 6% of men in the VTP group went on to undergo RT, compared with 29% in the surveillance group (P less than .0001). There were no significant differences between the two groups with respect to incontinence or erectile dysfunction.

In the extension study, similar patterns were seen at 3 and 4 years. At 4 years, 53% of men in the active surveillance group had converted to RT, compared with 24% in the treatment group (hazard ratio, 0.31; 95% confidence interval, 0.21-0.45). The absolute difference in risk for conversion to RT between the two groups was 3% at year 1, 26% at year 2, 30% at year 3, and 29% at year 4.

 

“It’s more of the same. Essentially there was about a 25% reduction in risk of conversion to radical treatment, and that benefit is maintained,” said Dr. Gill, professor and chair of urology at the University of Southern California, Los Angeles.

As expected, survival rates were similar at 4 years. In both groups, 99% were metastasis free, and cancer-specific survival was 100% in both. Overall survival was 98% in the VTP group, and 99% in the active surveillance group.

Currently, in very-low-risk patients, active surveillance is recommended and generally accepted. But many low-risk patients choose RT, putting them at risk for impotency and incontinence. “With this treatment, if you can maintain a 25% reduction in crossover treatment, then more men with low-risk prostate cancer are going to be spared radical treatment than if you were just doing active surveillance. And if you don’t get radical therapy, then your long-term quality of life is better,” said Dr. Gill.

VTP does lead to a small increase in risk of impotency and in incontinence in the short term, but patients tend to recover, and by 2 years, there is no significant difference between the groups.

Cryoablation and high-intensity focused ultrasound are also available. Those are effective, but they seem to have a higher profile of incontinence, impotency, and urethral injury, although they haven’t been directly compared to VTP, so comparing their side effect profiles “is literally comparing apples to oranges,” Dr. Gill said.

 

SAN FRANCISCO – In men with low-risk prostate cancer, vascular-targeted phototherapy (VTP) led to a significant reduction in subsequent conversions to radiation therapy or prostatectomy, compared with patients who underwent active surveillance. The latest results come at 4 years of follow-up, and confirm a reduction of risk seen in the original study at 2 years post treatment.

The new analysis was presented by Inderbir Gill, MD, in a late-breaking abstract session at the annual meeting of the American Urological Association.

About half of men with low-risk prostate cancer start out with active surveillance, but 25%-60% of them will go on to radical therapy (RT) within the next 5-10 years. Put another way, about 70% of men with low-risk prostate cancer will undergo RT within a decade. This protocol is generally effective, but it comes at a cost: Sixty-six percent of men undergoing radiotherapy and 82% of men undergoing prostatectomy experience incontinence, and 4% and 20%, respectively, experience erectile dysfunction at 2 years.

That adds up to an unmet clinical need: Patients with low-risk prostate cancer would be well served by an alternative therapy that cuts the risk of RT. VTP, along with alternatives cryoablation and high-intensity ultrasound, were developed to meet that need.

The original, phase 3 trial enrolled 413 men at 47 centers in Europe. Participants could have one cancer core that was free of Gleason patterns 4 or 5 as long as its length was between 3 and 5 mm. The study also included men with two or three positive cores, as long as the length was less than 5 mm, but they were excluded if they had Gleason patterns of 4 or 5.The participants were randomized to active surveillance or VTP, which consisted of 4 mg/kg padeliporfin delivered intravenously. Optical fibers inserted into the prostate to target the treatment zone were activated by laser light.

In the VTP group, 185 men completed 24 months of follow-up, as did 174 in the active surveillance group. Overall, 69% of the participants achieved follow-up at 3 years, and 64% at 4 years. At 2 years, 6% of men in the VTP group went on to undergo RT, compared with 29% in the surveillance group (P less than .0001). There were no significant differences between the two groups with respect to incontinence or erectile dysfunction.

In the extension study, similar patterns were seen at 3 and 4 years. At 4 years, 53% of men in the active surveillance group had converted to RT, compared with 24% in the treatment group (hazard ratio, 0.31; 95% confidence interval, 0.21-0.45). The absolute difference in risk for conversion to RT between the two groups was 3% at year 1, 26% at year 2, 30% at year 3, and 29% at year 4.

 

“It’s more of the same. Essentially there was about a 25% reduction in risk of conversion to radical treatment, and that benefit is maintained,” said Dr. Gill, professor and chair of urology at the University of Southern California, Los Angeles.

As expected, survival rates were similar at 4 years. In both groups, 99% were metastasis free, and cancer-specific survival was 100% in both. Overall survival was 98% in the VTP group, and 99% in the active surveillance group.

Currently, in very-low-risk patients, active surveillance is recommended and generally accepted. But many low-risk patients choose RT, putting them at risk for impotency and incontinence. “With this treatment, if you can maintain a 25% reduction in crossover treatment, then more men with low-risk prostate cancer are going to be spared radical treatment than if you were just doing active surveillance. And if you don’t get radical therapy, then your long-term quality of life is better,” said Dr. Gill.

VTP does lead to a small increase in risk of impotency and in incontinence in the short term, but patients tend to recover, and by 2 years, there is no significant difference between the groups.

Cryoablation and high-intensity focused ultrasound are also available. Those are effective, but they seem to have a higher profile of incontinence, impotency, and urethral injury, although they haven’t been directly compared to VTP, so comparing their side effect profiles “is literally comparing apples to oranges,” Dr. Gill said.