Androgen deprivation leads to bone loss in men with prostate cancer

Men starting on androgen deprivation therapy (ADT) for prostate cancer have a loss in bone mineral density (BMD) that may be as much as 10 times that of controls, researchers report in the December issue of the Journal of Clinical Endocrinology and Metabolism.

Dr. Susan L. Greenspan of the University of Pittsburgh and colleagues note that although bone loss is associated with ADT, little is known about when this may occur.To investigate further, the researchers studied 152 men with prostate cancer and healthy controls. In all, 30 of the patients had had acute treatment, having received ADT for less than 6 months, 50 had received it for 6 months or more and the remaining 72 were not receiving ADT.At 12 months, depending on the site of measurement, BMD loss ranged from 1 to 4% in men receiving acute ADT. In particular, the loss in BMD at the total radius was 3.3% in acute patients compared to just 2% in chronic ADT patients.No significant reduction in BMD was seen in patients not receiving ADT or controls. Overall, the researchers conclude that compared to such subjects, those initiating ADT have a 5- to 10- fold increase in bone density at multiple skeletal sites.Patients on acute ADT also had a 10.4% increase in body fat and a 3.5% reduction in total body lean mass. Such changes were not seen in the other subjects, including those on chronic ADT.Because the rate of bone loss “is maximal in the first year after androgen suppression is initiated,” the researchers suggest that “antiresorptive therapy may be most effective if prescribed during this period.”Recent studies, they add, suggest that roloxifene and zoledronic acid may be helpful in this regard. Oral biphosphonates may also be of use, but require further investigation.(Source: J Clin Endocrinol Metab 2005;90:6410-6417: Reuters Health: Oncolink: December 2005.)