Bone mineral density changes on androgen deprivation therapy for prostate cancer and response to antiresorptive therapy

Androgen deprivation therapy improves survival of patients with prostate cancer and leads to hypogonadal state. Gonadal hormones are essential for skeletal integrity and hypogonadism constitutes a major risk factor for osteoporosis. To examine the bone loss secondary to androgen deprivation therapy, we reviewed the bone mineral density ( BMD) studies of 152 patients with prostate cancer with mean duration of androgen deprivation therapy of 58 months. Among them 55 subjects had follow-up BMD measurement at 12-15 months with 39 of them on antiresorptive therapy. Osteoporosis was noted at least at one site in 92 (60.5%), among which 74 (48.7%) had changes at hip with the more prominent changes at ward's triangle, 18 (11.8%) at other sites. Osteopenia was present in 37 (24%) and only 17 (11%) were normal. The duration of antiandrogen therapy did not correlate with the degree of bone loss. Significant in improvement in the BMD is noted at 12-15 month follow-up on antiresorptive therapy. We conclude that men treated with androgen deprivation therapy are at risk for bone loss and should have BMD measured at the time of initiation of androgen deprivation therapy and periodically.