Effect on bone mineral density in surgical versus medical castration for metastatic prostate cancer.

Abstract

This pilot study aimed to objectively assess the osteoporotic effect caused by androgen deprivation therapy (ADT) in patients with prostate cancer and compare this effect in surgical versus medical castration, specifically with luteinizing hormone-releasing hormone (LHRH) antagonists. The study included 60 patients with metastatic prostate adenocarcinoma treated with either bilateral orchidectomy (group I) or LHRH antagonist (Degarelix) injection (group II). The patients had a baseline bone mineral density (BMD) assessment before the start of ADT using dual energy X-ray absorptiometry (DEXA) scan and then follow-up assessment after 6 months. BMD was measured at the spine (lumbar vertebrae L2-L4), femur (total), and forearm (one-third radius). Group I included 33 patients and group II 27 patients. Both the groups showed significant reduction in BMD at the spine and femur after 6 months, whereas the forearm did not show a significant reduction. Spine BMD showed 5.9%±2.6% and 4.7%±2.6% reduction whereas the femur BMD showed 6%±7.4% and 6%±4.7% reduction in the orchiectomy and the Degarelix groups, respectively. There was no statistically significant difference between the groups at the 3 measured sites. Both surgical castration and LHRH antagonists were associated with significant accelerated osteoporotic effect at the spine and femur after 6 months without difference between both the methods. Assessment of osteoporotic risk together with preventive or management measures should be started early during ADT.