Prostate cancer patients treated with either radiation or surgery who use hormone therapy for longer than six months do not survive any longer than patients who use the treatment for a shorter amount of time, according to a study presented November 5, 2006, at the American Society for Therapeutic Radiology and Oncology’s 48th Annual Meeting in Philadelphia.
“Many patients with high risk prostate cancer are treated with two or more years of hormone therapy based on studies performed over a decade ago,” said Cliff Robinson, M.D., lead author of the study and a radiation oncologist at Cleveland Clinic in Cleveland, Ohio. “Our study’s findings suggest that treating current patients with shorter-term hormone therapy may not only be equally effective, but also improve their quality of life, due to a lesser degree of treatment side effects.”
The authors also found that patients receiving longer than six months of hormone therapy were twice as likely to die as patients who use the treatment for a shorter amount of time. “The reasons why patients receiving longer term hormone therapy may do worse are unclear,” said Dr. Robinson, who also cautions, “A number of factors could complicate the issue, and this area needs further investigation before any conclusions can be drawn.”
Androgen deprivation therapy is a hormone therapy used to treat prostate cancer by lowering the level of male hormones (androgens) to shrink or slow down the growth of prostate cancer. It has been shown to dramatically slow advanced prostate cancer that has already spread to the lymph nodes or the bone, and improves survival when combined with radiation therapy in advanced prostate cancer that has not already spread.
Several side effects are common to androgen deprivation therapy and are a direct result of decreased androgen levels. Side effects vary significantly depending on the amount and length of time the hormone therapy is given. Potential side effects include reduced sexual desire, impotence, hot flashes, weakening of the bones, breast tenderness or breast growth, as well as other conditions.
The study reviewed 579 patients who were treated at the Cleveland Clinic with high risk prostate cancer from 1996 to 2003. These patients were divided into three groups – one that received no androgen deprivation therapy, one that had received six months or less of androgen deprivation therapy, and one that received more than six months of treatment – to determine if longer use of hormone therapy stopped cancer from growing and lengthened survival.