Providing radiation therapy to men with rising prostate-specific antigen (PSA) levels following radical prostatectomy improves survival, a new study suggests.
Link: Radiation for Recurrent Prostate Cancer Appears to Improve Survival
Presenting at the 2008 Genitourinary Cancers Symposium in San Francisco, California, researchers showed that salvage radiotherapy reduced the risk of dying from prostate cancer by more that 60%. Investigators observed the greatest benefit in men with rapidly rising PSA levels, and found that the advantages of therapy appeared to persist even when administered up to 2 years after levels began to rise.
"These findings are the first to support the effectiveness of salvage radiotherapy for improving survival in men with recurrent prostate cancer," lead author Bruce Trock, MD, from Johns Hopkins University School of Medicine in Baltimore, Maryland, told reporters.
"If validated, these results suggest that, for high-risk prostate cancer, radiotherapy should be given promptly when there is evidence of recurrence after radical prostatectomy, as early salvage radiotherapy may improve overall survival." But, he emphasized, this is a retrospective analysis and will require further study.
During an interview with Medscape Oncology, press-conference moderator Howard Sandler, MD, from the University of Michigan Health System in Ann Arbor, said he agreed that more work is needed.
"But I like this study," he noted. "There has been some skepticism among urologists that radiation therapy works and I think there has also been some hesitation to admit the primary treatment failed," he said. "This study shows that men who got salvage radiation lived longer. This should encourage urologists to promptly refer patients to a radiation oncologist."
Recurrence Should Prompt Immediate Radiotherapy, Study Suggests
In the current analysis, researchers compared prostate-cancer-specific survival among men with biochemical recurrence. Of these patients, 160 received salvage radiotherapy alone, 78 received radiation plus hormonal therapy, and 397 had no radiation or hormonal therapy.
After 10 years, 86% of men in the salvage radiotherapy group and 82% of men in the radiation with hormonal therapy group had not died from prostate cancer. The number for men who received no salvage therapy was lower, at 62%. Dr. Trock and his team report that these results did not change after taking into account individual patient characteristics associated with prognosis.
"Early salvage treatment was critical," report the researchers. "Salvage radiotherapy improved prostate-cancer-specific survival only if given up to 2 years after biochemical recurrence."
The benefit of salvage radiotherapy was particularly strong in men with aggressive disease whose PSA levels doubled in less than 6 months. Radiation reduced the risk for prostate cancer death in these patients by 86%.
The researchers found that therapy did not significantly reduce the risk for death among men whose PSA levels doubled in 6 months or more. They suggest this could be because these patients had less aggressive disease and may have done well even without radiation.
Dr. Sandler applauded the researchers. "It is a relatively robust finding that strongly supports the use of radiotherapy in this setting," he said. "But," he added, "this was a restrospective design and patients were not randomly assigned and there is potential for some unknown bias."
Dr. Trock told reporters that despite this new evidence that salvage radiotherapy improves survival, confirmation is needed in other comparable groups of men and ultimately, a randomized clinical trial is required.
The researchers report having financial ties to Oncomethylome Sciences, Johnson & Johnson, and Veridex LLC.
Source: Medscape Medical News
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