Osteoporosis in men treated with androgen deprivation therapy for prostate cancer.

PURPOSE We surveyed the growing literature on osteoporosis secondary to androgen deprivation therapy and provide suggestions regarding its identification and treatment. MATERIALS AND METHODS We reviewed pertinent studies of male osteoporosis, osteoporotic fracture incidence or bone mineral density loss as a possible side effect of prostate cancer treatment and potential therapies for this side effect. RESULTS Hypogonadism is a well-known cause of secondary osteoporosis in men. There is evidence of decreased bone mineral density with all types of androgen deprivation therapy, presumably due to its anti-testosterone effect. Bone mineral density loss is 3% to 5% yearly in the first few years of androgen deprivation therapy with an increase in osteoporotic fracture incidence. There are little data on potential treatments, although bisphosphonates and intermittent androgen deprivation therapy may have salutary effects. CONCLUSIONS Osteoporosis is an important and debilitating side effect of androgen deprivation therapy, although precise estimates of its incidence, degree and cost are not completely elucidated. Until more data are available, it is prudent for all men beginning androgen deprivation therapy to receive calcium and vitamin D, and maintain a moderate exercise regimen. Baseline and at least 1 followup bone density measurement seem appropriate with bisphosphonate treatment a possibility in those in whom osteoporosis develops. More research is needed to explore the effect of bisphosphonates, calcium and vitamin D supplementation, exercise, calcitonin, selective estrogen re-uptake inhibitors, estrogens and intermittent androgen deprivation therapy on the course of androgen deprivation therapy induced osteoporosis. The osteoporotic fracture incidence and bone mineral density should be regularly incorporated into studies involving the hormonal treatment of prostate cancer.