Treatment with a combination of hormone therapy and radiation therapy (RT) improves overall and disease-specific survival in men with locally advanced prostate cancer compared with hormone therapy alone, according to interim results of a study presented at the 52nd Annual Meeting of the American Society for Radiation Oncology.
The study is “practice-changing,” according to lead investigator Malcolm Mason, MD, of Cardiff University, Cardiff, Wales, United Kingdom. “It shows that the standard treatment for these [high-risk prostate cancer] patients should now be hormone therapy plus radiation.”
From 1995 to 2005, 1205 men with locally advanced prostate cancer were randomly selected to receive androgen-deprivation therapy (ADT) alone or a combination of ADT and external beam RT. Median follow-up was 6 years.
Interim results of the study show that the addition of RT to ADT significantly reduced the risk of death among these patients. A total of 140 patients have died of prostate cancer and/or treatment, 89 on ADT and 51 on ADT plus RT. The 10-year cumulative disease-specific death rates were an estimated 15% with ADT plus RT versus 23% with ADT alone. There was no significant difference in late treatment toxicity with combination therapy. Longer follow-up is ongoing.
“If the figures from the interim analysis are similar to the final analysis, we would expect a 43% reduction in the chances of death from prostate cancer in men with this regimen,” said Mason. “This would translate into a reduction in the chances of deaths from prostate cancer in many thousands of men worldwide.”