Long-term Exposure to Testosterone Therapy and the Risk of High Grade Prostate Cancer.

ABSTRACT

PURPOSE: To our knowledge no population based studies have been done to examine whether long-term exposure to testosterone therapy is associated with an increased risk of high grade prostate cancer. We examined whether exposure to testosterone during a 5-year period was associated with an increased risk of high grade prostate cancer and whether this risk increased in a dose-response fashion with the cumulative number of testosterone injections. MATERIALS AND METHODS: Using SEER (Surveillance, Epidemiology and End Results)-Medicare linked data we identified 52,579 men diagnosed with incident prostate cancer between January 1, 2001 and December 31, 2006 who had a minimum of 5 years continuous enrollment in Medicare before the cancer diagnosis. We excluded patients diagnosed at death or after autopsy, those enrolled in a health maintenance organization in the 60 months before diagnosis and those with unknown tumor grade or tumor stage. In the 5 years before diagnosis 574 men had a history of testosterone use and 51,945 did not. RESULTS: On logistic regression adjusting for demographic and clinical characteristics exposure to testosterone therapy was not associated with an increased risk of high grade prostate cancer (OR 0.84, 95% CI 0.67-1.05) or receipt of primary androgen deprivation therapy following diagnosis (OR 0.97, 95% CI 0.74-1.30). In addition the risk of high grade disease did not increase according to the total number of testosterone injections (OR 1.00, 95% CI 0.98-1.01). CONCLUSIONS: Our finding that testosterone therapy was not associated with an increased risk of high grade prostate cancer may provide important information regarding the risk-benefit assessment for men with testosterone deficiency considering treatment.