Treatment with a gonadotropin-releasing hormone agonist decreases bone mineral density and increases the risk of fracture in men with prostate cancer. We conducted a controlled study of the prevention of osteoporosis in men undergoing treatment with a gonadotropin-releasing hormone agonist.

In a 48-week, open-label study, we randomly assigned 47 men with advanced or recurrent prostate cancer and no bone metastases to receive either leuprolide alone or leuprolide and pamidronate (60 mg intravenously every 12 weeks). Bone mineral density of the lumbar spine and the proximal femur was measured by dual-energy x-ray absorptiometry. Trabecular bone mineral density of the lumbar spine was measured by quantitative computed tomography. Forty-one men completed the study.

In men treated with leuprolide alone, the mean (±SE) bone mineral density decreased by 3.3±0.7 percent in the lumbar spine, 2.1±0.6 percent in the trochanter, and 1.8±0.4 percent in the total hip, and the mean trabecular bone mineral density of the lumbar spine decreased by 8.5±1.8 percent (P<0.001 for each comparison with the base-line value). In contrast, the mean bone mineral density did not change significantly at any skeletal site in men treated with both leuprolide and pamidronate. There were significant differences between the two groups in the mean changes in bone mineral density at 48 weeks in the lumbar spine (P<0.001), trochanter (P=0.003), total hip (P=0.005), and trabecular bone of the lumbar spine (P=0.02).

Pamidronate prevents bone loss in the hip and lumbar spine in men receiving treatment for prostate cancer with a gonadotropin-releasing hormone agonist.