Preferential preservation of bone mineralisation by LHRH agonists in the treatment of metastatic prostate cancer.

Abstract

Histomorphometric measurements of tumour-free bone have been undertaken in a closely matched group of patients with metastatic prostate cancer treated either by subcapsular orchidectomy (SCO) or luteinising hormone-releasing hormone (LHRH) agonists. Age, fasting morning urine hydroxyproline/creatinine ratios, alkaline and acid phosphatase levels and elapsed time after hormonal manipulation were similar in those receiving SCO (n = 8) as compared to LHRH therapy (n = 8). Results indicated that osteoid surface and mineralisation rate were significantly reduced in the SCO group (p less than 0.05); other indices were also lower in the SCO patients but failed to reach statistical significance. These changes, possibly due to increased adrenal cortical stimulation secondary to elevated gonadotrophin levels following orchidectomy suggest that medical castration by gonadotrophin inhibition may avoid unnecessary morbidity due to treatment-induced bone dysfunction.