Long Term Hormone Therapy
Men with prostate cancer who do not have a high risk of recurrence or disease progression do not need to have long-term hormone therapy in addition to external-beam radiation therapy if they receive high radiation doses. That is the finding of a Fox Chase Cancer Center study presented today at the 46th Annual Meeting of the American Society for Therapeutic Radiology and Oncology in Atlanta, Ga.
"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.