[Clinical significance of risedronate for patients with prostate cancer receiving androgen deprivation therapy].

Purpose: Androgen deprivation therapy (ADT) in patients with prostate cancer is associated with bone loss. We investigated the effectiveness of risedronate about a decreasing bone mineral density in patients with prostate cancer on ADT.

Material And Method: A prospective study was conducted in Kitasato University Hospital from April 2004 to October 2006. A total of 69 men with prostate cancer were assigned to receive either oral risedronate or none during ADT (hormone naïve). The treatment group was 58 men and taking 2.5 mg risedronate per day. The control group was 11 men. At baseline, we assessed BMD (bone mineral density) by DEXA and urinary NTX, and measured for these changes every 6 months.

Result: At baseline, each BMDs had no significant difference at the lumber and total hip. At the first 6-month stage, the change in BMD percentage between the 2 groups was statistically significantly different at lumber (p = 0.002) and total hip (p = 0.038). At the 12-month stage, the change in the BMD percentage between the 2 groups was statistically significantly different at the lumber (p = 0.038). And each difference made out that the risedronate group was preserving BMD. In urinary NTX, bone turn over was statistically significantly decreased with the risedronate group compared with the control group at the 12-month stage (p = 0.017).

Conclusion: We assure the beginning of bone loss at an early date (6 months) with ADT. Daily oral risedronate in patients with receiving ADT reduces bone mineral loss and maintain BMD.