Risedronate prevents persistent bone loss in prostate cancer patients treated with androgen deprivation therapy: results of a 2-year follow-up study.

Androgen deprivation therapy (ADT) for prostate cancer (PCa) causes bone loss. Although we reported previously that risedronate significantly recovers bone mineral density (BMD) for up to 12 months, there have been no reports with longer follow-up periods to date. This study extended our earlier series extending the follow-up period to 24 months. Eligible patients had histologically confirmed PCa without lumbar spine metastasis and underwent ADT. Lumbar spine BMD, urinary deoxypyridinoline (uDPD) and serum bone alkaline phosphatase were measured at 6, 12 and 24 months. Among the total of 96 patients, we analyzed 26 and 18 patients in risedronate administration and control groups, respectively. BMD relative to the young adult mean ratio, uDPD and serum bone alkaline phosphatase of the risedronate administration group recovered significantly after 24 months compared with the control group (P<0.0001, P=0.0001, and P<0.0001, respectively). Transient blurred vision, malaise and vertigo were observed in 1 patient each among the 46 patients treated with risedronate within 28 days after first administration. Oral administration of risedronate is safe and effective for the recovery of ADT-induced bone loss in PCa patients even at 24 months after commencement of treatment.