Risedronate prevents early bone loss and increased bone turnover in the first 6 months of luteinizing hormone-releasing hormone-agonist therapy for prostate cancer.

OBJECTIVE

To determine whether increased bone loss and bone turnover during the first 6 months of therapy for prostate cancer with luteinizing hormone-releasing hormone (LHRH)-agonist therapy could be prevented by bisphosphonate therapy with risedronate 35 mg/week, as prostate cancer is commonly treated with LHRH agonists and this often leads to rapid bone loss within the first 6 months of therapy.

PATIENTS AND METHODS

A 6-month randomized, double-blind, placebo-controlled trial was conducted, including 40 men aged ≥ 55 years receiving LHRH-agonist treatment for 6 months for locally advanced prostate cancer. Bone mineral density (BMD) of the lumbar spine, femoral neck, and total hip was measured every 6 months. In addition, bone turnover markers including N-telopeptide, serum C-telopeptide and procollagen peptide, and 25-OH vitamin D and intact parathyroid hormone were measured at baseline and at 6 months.

RESULTS

After 6 months of LHRH-agonist therapy, the control group had a significant decline at the spine and hip BMD sites; however, the risedronate group had no bone loss at the hip and an increase at the lumber spine. Markers of bone turnover were increased significantly in the control group but unchanged in the risedronate group.

CONCLUSIONS

LHRH-agonist treatment for locally advanced prostate cancer produces increased bone turnover and rapid bone loss within the initial 6 months of therapy, and this can be prevented by weekly risedronate treatment.