Androgen deprivation therapy for prostate cancer results in significant loss of bone density

Objectives. Advanced prostate cancer is a frequently diagnosed condition in the aging male population, and many men will ultimately be treated with an drogen deprivation therapy (ADT). Long-term consequences of ADT on bone min eral density (BMD) have not been systematically studied. We performed a pil ot study to test the hypothesis that ADT in patients with prostate cancer r esults in the measurable loss of BMD. Methods. A cross-sectional study of 32 men with prostate cancer who were ab out to begin ADT or who had been receiving ADT for more than 1 year was con ducted. BMD was measured by single and dual energy x-ray absorptiometry in the lumbar spine, hip, and forearm. Linear regression analysis was used to estimate the time necessary to develop significant BMD loss in the spine, h ip, and forearm regions. Results. Five (63%) of 8 men who had not received ADT and 21 (88%) of 24 me n who had received ADT for more than 1 year fulfilled the BMD criteria for osteopenia or osteoporosis at one or more sites. When BMD was compared at e ach site, men who received ADT for more than 1 year had significantly lower BMD in the lumbar spine than men who had not started treatment (P <0.05). On the basis of regression analysis, an estimated 48 months of ADT would be necessary to develop BMD criteria for osteopenia in the lumbar spine for a man with average BMD at the initiation of therapy. Conclusions. Pre-existing osteopenia and osteoporosis were common in men wi th prostate cancer before initiating ADT. Both ADT and the duration of ADT were significantly associated with the loss of BMD in men with prostate can cer.