Prostate cancer therapy linked to bone loss

Bone mineral density, a measure of bone thickness, decreases during the first 2 years of androgen deprivation therapy in men with prostate cancer, according to a report in The Journal of Urology.

Androgen hormones, such as testosterone, stimulate prostate tissue and can accelerate the growth of any prostate cancer. Androgen deprivation, with drugs or surgery, can reduce this stimulation.

Bone density measurement before beginning androgen deprivation therapy is important, because about 20 to 30 percent of these patients will have osteoporosis, a bone-thinning disease, Dr. Juan Morote told Reuters Health. He pointed out that it's important "to know the health of bone in prostate cancer patients in order to prevent bone fractures, which are a bad prognostic factor of survival."

Morote and colleagues from Vall d'Hebron Hospital, Autonoma University School of Medicine, Barcelona, Spain evaluated the dynamics of bone mineral density in the spine and hip over a 2-year period in 62 men with prostate cancer.

Men receiving androgen deprivation therapy experienced bone mineral density losses ranging from 2.29 to 5.55 percent after 12 months, the authors report, whereas bone mineral density did not change significantly in men not on androgen suppression. At 24 months, however, there was evidence that the bone loss had slowed down.

The area that best reflected the androgen deprivation-induced bone loss was in a region of the hip called Ward's triangle, the researchers note.

"Many physicians have used simple forearm (bone) scans, which can be quickly and easily obtained in their office," Dr. Jeffrey M. Holzbeierlein from University of Kansas Medical Center, Kansas City, notes in a related editorial. "This report suggests that this may not accurately reflect the greatest extent of bone loss, which may lead to a delay in appropriate treatment."

SOURCE: The Journal of Urology, May 2006.