The Effect of Bisphosphonates on Bone Mineral Density in Metastatic Prostate Cancer Patients Who Are Treated with Anti-Androgen Drugs and Radiotherapy

Curr Urol. 2014 Oct;7(4):181-4. doi: 10.1159/000365672. Epub 2014 Aug 20.

Abstract

Objective: To evaluate the potential effect of bisphosphonates on bone mineral density (BMD) in patients who are treated with anti-androgen drugs and radiotherapy for metastatic prostate cancer.

Materials and methods: The data of 31 patients with metastatic prostate cancer who were treated with anti-androgen drugs and radiotherapy during a 1-year period were retrospectively reviewed. Patients were divided in 2 groups, in which 17 patients in group 1 were treated with zoledronic acid (4 mg/month, intravenous) and 14 patients in group 2 who did not receive zoledronic acid. BMD was measured before the treatment and at the end of the 1st year by dual energy X-ray absorptiometry. Statistical analyses were performed with the T test.

Results: Mean age of the patients was 71.42 ± 6.7(range 59-85) years. A significant increase was noted for pelvic bone, femoral neck, and lumbar vertebrae t scores when pretreatment and 1st year measurements were compared in group 1 (p < 0.05). In group 2 a significant decrease was noted for pelvic bone and femoral neck t scores at the end of the 1st year (p < 0.05). A significant increase was noted for pelvic bone and femoral neck follow-up in BMD values at the end of the 1st year compared to initial measurements in group 1. A significant decrease was noted for lumbar vertebrae follow-up in BMD values at the end of the 1st year when compared to initial values in group 2.

Conclusion: Zoledronic acid significantly increases BMD and delays unfavorable outcomes for bones in men who are treated with anti-androgen drugs and radiotherapy for metastatic prostate cancer.

Keywords: Bisphosphonate therapy; Metastatic prostate cancer; Osteoporosis; Radiotherapy.