A phase II trial was just completed at the University of Western Australia to investigate changes in bone mineral density (BMD) and osteoporosis in men on intermittent androgen-suppression therapy (IAST) over a period of three years.
This trial, conducted at the Faculty of Medicine, University of Western Australia, Crawley, Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, WA, Australia was a Phase II individual cohort study of 72 men with prostate cancer without metastatic bone disease. Enrollment for the trial was between 1999 and 2002.
All the men had 9 months flutamide (250 mg, three times daily) and leuprolide (22.5 mg, 3-monthly depot) after which, men ceased therapy providing that their PSA levels were < 4 ng/mL. AST re-commenced when the PSA level exceeded the pretreatment level or was >20 ng/mL. BMD for hip and spine was the primary endpoint; assessed at baseline; completion of initial treatment period; and at 1 and 2 years after initial treatment (POST period).
Osteoporosis increased from 7% at baseline to 10% at 3 years. The BMD declined after 9 months treatment, at -1.9% and -3.3% at hip and spine, respectively (P < 0.001). Subsequent BMD decline in the POST period was attenuated; at 1 years and 2 years later, hip -0.6% (not significant), and -0.8% (P < 0.014), and spine +1.0% and +0.2% (not significant). The BMD change in those remaining 'off' therapy for 2 years (n = 20) was strongly associated with the level of testosterone recovery; a peak testosterone level of < 5 nmol/L associated with a greater then normal physiological loss. Testosterone recovery was less likely in the older men.The attenuation of spine and hip BMD decline after 3-year IAST compared with those reported for continuous AST appears to be due to testosterone driven BMD recovery in the POST period. Failure of testosterone recovery was associated with worse final BMD. By reducing the potential risk for adverse bone complications, intermittent therapy may become an important consideration when the therapeutic ratio is narrow.These results were intuitive, but the scientific confirmation of them is important. What does it mean? These results are another indicator that you should consider intermittent hormone therapy, not only will you feel better, but you will slow down the eventual loss of BMD providing you experience testosterone recovery.BJU Int. 2009 Mar 5. Epub ahead of print. doi:10.1111/j.1464-410X.2009.08458.xJoel T Nowak MA, MSW
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