Prostate cancer is the most common malignancy in men, with 15 to 25 percent of cases classified as high-risk, but researchers have shown that men with locally advanced or high-risk prostate cancer who receive combined radiation and hormone therapy live longer and are less likely to die from their disease, according to a study published online on Nov. 2 in The Lancet.
Padraig R. Warde, FRCPC, MB, deputy head of the radiation medicine program at Princess Margaret Hospital Cancer Program, University Health Network in Toronto, and colleagues wanted to study the effect of combined radiotherapy (RT) and androgen deprivation therapy (ADT) compared with using ADT alone.
"The study shows combining radiation and hormone therapy improves overall survival by 23 percent and disease-specific survival by 43 percent, compared with treating with hormone therapy alone,” Warde said in a statement. "Based on these results, we believe adding radiation to the treatment plan should become part of the standard therapy."
The study involved 1,205 patients enrolled between 1995 and 2005, with 602 randomized to receive ADT only and 603 to receive ADT and RT. Median follow-up time was six years.
At the time of analysis, 320 patients had died, 175 in the ADT-only group and 145 in the combined ADT and RT group. Among those in the hormone-only group, 26 percent died from their prostate cancer compared with 10 percent in the group that received hormone therapy and radiation.
Serious long-term genitourinary or gastrointestinal toxicity from RT was uncommon, and low numbers of serious adverse events were recorded in each group.
"Our findings suggest that the benefits of the combination of ADT and RT should be discussed with all patients considering a curative treatment approach," wrote the authors.
Warde added that the benefits of combined therapy could be even greater now given recent advancements in the development of targeted radiation techniques
In an accompanying comment, Matthew R. Cooperberg, MD, MPH, of the department of urology at the University of California, San Francisco, said the study had provided the strongest evidence yet that hormone therapy alone is not enough. "However, the crucial question—whether the optimum initial strategy should include radiation combined with androgen deprivation therapy, or surgery followed by selective radiation on the basis of pathological findings and early biochemical outcomes—is still open,” he said, adding the answer will come with more randomized trials.