Oral bisphosphonates fail to prevent bone loss from androgen deprivation therapy in men with prostate cancer

14643 Background: Androgen deprivation therapy (ADT) is a widely administered treatment for prostate cancer. However, ADT is associated with accelerated bone loss, osteoporosis, and fractures (Shahinian, NEJM 2005; 352:154). According to Smith et al, annual bone loss on ADT approaches 9% (Smith, NEJM 2001;345:948), using QCT densitometry, a highly sensitive test for the detection of osteoporosis in men. Intravenous bisphosphonates (pamidronate, zolendronate) have been shown to prevent ADT-related bone loss in randomized phase III trials. We performed a retrospective analysis to determine if oral bisphosphonates effectively prevent bone loss in men receiving ADT. Methods: Twenty two men, ages 60–80, were placed on alendronate or risendronate at the initiation of ADT. Baseline and follow-up bone mineral densitometry (BMD) studies were performed with QCT densitometry. Repeat BMD was performed 12- 27 months (mean = 17mo) after the baseline BMD. Percentage change in bone density was annualized. Within each tre...