Effects of zoledronate (Z) on bone mineral density (BMD) among African Americans (AA) with advanced prostate cancer, without skeletal metastases, receiving androgen ablation therapy

Abstract

16031 Background: Bone health is a particular concern for patients undergoing androgen ablation for treatment of prostate cancer, as it has been known to cause bone loss. These issues are especially important in AA, who present with higher rates of advanced disease and are more likely to choose androgen ablation therapy than white patients. Bisphosophonates, such as Zoledronate (Z), are often used by cancer patients who experience bone metastases. We evaluated the effects of Ca/Vitamin D ± Z on skeletal related events and BMD on AA and white prostate cancer patients undergoing androgen ablation therapy. Methods: Prostate cancer patients receiving at least 3 months of androgen ablation were eligible. Exclusion criteria: Use of bisphosphonates in last 12 months, abnormal liver/kidney function, or prior bone disease. 42 patients were randomized, 51% of which are AA. Patients on the Z arm received 4 mg IV infusion of Z q 3 months over one year. Bone densities were evaluated at baseline and 13 months. Results: Interim analysis is available for patients who have completed the study as of Jan 2008. Three patients were taken off the study (one due to secondary cancer, two due to patient withdrawal). One patient withdrew due to jaw pain; follow up did not identify osteonecrosis. Two patients had lesions that may have been bone metastases; follow up testing was inconclusive. Patients treated with Z had higher BMD scores than control group patients. AA patients treated with Z also showed increased BMD values at 13 months. Conclusions: Z appears to have a positive effect on BMD in AA men with prostate cancer, an effect potentially more beneficial than previously reported for white men with prostate cancer. AA men with prostate cancer receiving long term androgen ablation should be considered for Z therapy to improve bone health. % Change in BMD All Control (C) All w/Z AA (C) AA w/Z Non AA (C) Non AA w/Z Lumbar Spine 0.75* 4.29* 2.53 3.76 -1.53* 5.08* Hip -2.39* 0.96* -1.19 0.77 -3.96* 1.26* Femur -0.90** 3.51* -1.77** 6.13* 0.23 -0.40 * = p value <.05, ** = .05–1.0 Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Amgen, Novartis Oncology, sanofi-aventis