Prostate cancer of the bone

ARLINGTON, VA. -- Estradiol pre vents bone loss in prostate cancer patients taking luteinizing hormone-releasing hormone analogues, Dr. Pam Taxel reported at the Clinical Research 2001 meeting.

LHRH therapy is no longer reserved for men with metastatic prostate cancer. LHRH therapy is being given to men whose prostate-specific antigen levels begin to rise after surgery and to men with locally advanced disease, said Dr. Taxel of the University of Connecticut, Farmington.

LHRH decreases estradiol and testosterone levels and promotes bone loss. Men on LHRH agents such as leuprolide and goserelin for only 6 months have a 2% loss of bone density at the hip, compared with the 0.5% decrease seen in that time frame in normal, healthy men of the same age.

Dr. Taxel and her associates measured bone turnover in 18 prostate cancer patients who had taken LHRH for 1-2 years. The subjects' mean age was 70 years.

Eight were randomly assigned to receive oral estradiol and 10 to receive placebo. Both groups had similar prostate-specific antigen levels and body mass indexes.

After 6 weeks of treatment, levels of estradiol and estrone were restored to normal male values in the treated group only. Two markers of bone resorption, which had been elevated in all subjects at the start of the study, dropped 36% in the treated group but not in the placebo group.

This effect is nearly identical to that achieved in postmenopausal women taking estrogen therapy, Dr. Taxel said at the meeting, sponsored by the American Federation for Medical Research

The treatment was well tolerated, with minimal side effects. It had the additional benefit of decreasing the number of hot flashes these patients experienced.

"In men on long-term LHRH therapy, replacement of estradiol to the normal physiologic male range decreases bone turnover. Estradiol therapy thus prevents bone loss in men taking hormonal suppression for prostate cancer," she said.