The largest study examining the benefits of long-term use of hormone therapy after radiation treatment for prostate cancer shows men with aggressive locally advanced disease live longer if hormones are used for an additional 24 months. Research also showed other significant benefits for those with less aggressive cancers who receive hormones. The study results were presented today at the 48th Annual Meeting of the American Society for Therapeutic Radiology and Oncology in Philadelphia.
The study, sponsored by the Radiation Therapy Oncology Group (RTOG 92-02), reports more than 10 years of data involving the use of androgen deprivation after radiation therapy in a phase III, multi-center study led by Gerald E. Hanks, M.D., who served as chairman of radiation oncology at Fox Chase Cancer Center from 1985 to 2001. (Hanks is a 2006 ASTRO Fellow).
The study included 1,554 men with locally advanced prostate cancer. Everyone received approximately four months of hormone therapy (goserelin and flutamide) before and during their radiation treatments. After radiation treatment, the patients were randomized into two groups: to receive additional hormones (24 months of goserelin) or to receive no further hormone therapy. Patients received conventional external beam radiation. Median follow-up was more than 10 years for both groups.
"At 10 years, the men receiving an additional 24 months of hormones showed significant benefit over those not taking additional hormone therapy," said Hanks. The survival benefit was not present for the overall group, but became apparent when subgroups were analyzed, explained Hanks.
The study showed a benefit in the following areas: disease-free survival (13.2 percent vs. 22.5 percent), disease-specific survival (83.9 percent vs. 88.7 percent), local progression (22.2 percent vs. 12.3 percent), distant metastasis (22.8 percent vs. 14.8 percent), and biochemical failure (68.0 percent vs. 51.9 percent).
Hanks added, "All men with aggressive cancer (Gleason score of 8 to 10) who received hormone therapy showed a survival benefit of 31.9 versus 45.0 percent as well as other significant endpoints."