Androgen-deprivation therapy (ADT) decreases bone mineral density (BMD) and increases fracture risk in patients with prostate carcinoma. The authors investigated the effectiveness of a single infusion of zoledronic acid initiated subsequent to ADT on BMD with hormone-naive prostate carcinoma.
Forty men received either a single infusion of zoledronic acid (4 mg intravenously on Day 1) or no infusion during ADT. BMD of the proximal femur and posteroanterior lumbar spine was measured by dual-energy x-ray absorptiometry and urinary N-telopeptide (u-NTx) at 6 and 12 months.
At baseline, the overall BMDs demonstrated no significant difference in lumbar spine and hip regions. At 6months, mean (±standard error) BMD of the posteroanterior lumbar spine decreased 4.6% ± 1.0% in control patients and increased 5.1% ± 1.2% in patients receiving zoledronic acid, a significant difference (P = .0002). At 12 months, the change in BMD between the 2 groups was statistically significantly different at the lumbar region (P = .0004), indicating that zoledronate preserved BMD. For u-NTx, bone turnover was statistically significantly decreased in the zoledronate group compared with controls at 6 months (P < .0001), but returned to pretreatment levels at 12 months in the zoledronate group.
Bone loss begins at 6 months with ADT. A single infusion of zoledronic acid in patients receiving ADT reduces bone mineral loss and maintains BMD at least at 12 months during ADT. Further study is needed to determine the best dosing schedule to prevent ADT-induced bone loss in men with hormone-naive prostate carcinoma. Cancer 2009. © 2009 American Cancer Society.