Androgen deprivation therapy associated with weakening of cortical and trabecular bone

Hamilton ES. J Clin Endocrinol Metab. 2010;doi:10.1210/jc.2010-0902.

Researchers used a new type of virtual bone biopsy to determine that men with prostate cancer had reduced bone density after 12 months of treatment with androgen deprivation therapy.

Researchers enrolled 26 men who were scheduled to begin 12 months of androgen deprivation therapy (ADT) for nonmetastatic prostate cancer. Patients were evaluated at baseline, 6 months and 12 months using the new technique of high-resolution peripheral quantitative CT. This virtual bone biopsy allows in vivo assessment of trabecular architecture and volumetric bone mineral density at the distal tibia and radius.

At 12 months, total volumetric BMD at the distal radius decreased by 5.2 ± 5.4% because of a 3.4 ± 3.1% decline in cortical density.

Researchers found that total trabecular density did not change, but they observed a decline in inner trabecular density of 2 ± 7.5%. The cortical area decreased (–11.5 ± 8.8%), as did cortical thickness. The trabecular area increased by 1.7 ± 1.8%.

At the distal tibia, total volumetric BMD decreased by 4.2 ± 2.7% because of a decrease in cortical density (–3.9 ± 3.3%) and inner trabecular density (–1.6 ± 2.5%). No change in total trabecular density was observed.

Cortical area decreased (–12.5 ± 7.4%), as did cortical thickness. The trabecular area increased by 1.4 ± 7.3%.

“ADT for the treatment of prostate cancer is associated with structural decay of cortical and trabecular bone. Bone loss in this group may be more strongly associated with testosterone than [estradiol] deficiency,” the researchers concluded. “Men on ADT for prostate cancer are at increased risk of fractures, and assessment of bone microarchitecture by high-resolution peripheral quantitative computed tomography is likely to be a useful tool to assist fracture prediction in this group.”

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