"Several large randomized clinical trials have shown that patients with high-risk disease may live longer if they have long-term androgen deprivation in addition to radiation therapy," said the study's lead author, Fox Chase radiation oncologist Shelly B. Hayes, M.D. Features of high-risk disease include a Gleason score of 8 to 10, stage T3 to T4 cancer and/or a PSA level greater than 30.
"The purpose of our study was to determine if certain patients with less aggressive disease might be treated inadequately with radiation alone and would benefit from the addition of hormone therapy," Hayes said. "It turns out that radiation dose is the critical factor and additional treatment is unnecessary."
The researchers analyzed treatment and outcomes of 496 men treated with three-dimensional conformal radiation therapy during the 10-year period between 1991 and 2001. The group that did best included patients with Gleason scores of 2 to 6 who received doses equal to or greater than 72 Gy or patients with a Gleason score of 7 who received doses equal to or greater than 76 Gy. (A Gy or "gray" dose is a measure of the radiation absorbed by the targeted organ.)
In contrast, patients with the worst treatment outcomes were those with a Gleason score of 7 who received less than 76 Gy and those with a PSA level greater than 10 who received less than 72 Gy of radiation.
The Fox Chase researchers concluded that patients with intermediate-risk prostate cancer do not need long-term androgen deprivation if they receive high-dose radiation--greater than 76 Gy. Along with Hayes, study authors included statistician Alexandra L. Hanlon, Ph.D., radiation oncologist Eric M. Horwitz, M.D., radiation oncology chairman Alan Pollack, M.D., Ph.D., urologic oncologist Robert G. Uzzo, M.D., and radiation oncologist Steven J. Feigenberg, M.D.
Fox Chase Cancer Center was founded in 1904 in Philadelphia as the nation's first cancer hospital. In 1974, Fox Chase became one of the first institutions designated as a National Cancer Institute Comprehensive Cancer Center. Fox Chase conducts basic, clinical, population and translational research; programs of prevention, detection and treatment of cancer; and community outreach. For more information about Fox Chase activities, visit the Center's web site at www.fccc.edu or call 1-888-FOX CHASE.