Estrogen Patch Helpful in Prostate Cancer

NEW YORK (Reuters Health) - Men with advanced prostate cancer are prone to develop dangerous blood clots, but treatment with an estrogen patch may reduce this risk, UK researchers report

The patch is also a helpful anti-tumor agent, since prostate cancer is driven by male hormones, the team reports in the Journal of Urology.

"In summary," senior investigator Dr. Paul D. Abel told Reuters Health, "our data show that transdermal estrogen reduces activation of (blood clotting) factors and so may actually protect against thrombosis."

However, he added, "This hypothesis is exciting, but will require further research in larger numbers of patients."

Abel, of Imperial College, London, and colleagues previously established that delivering estrogen via a skin patch led to a tumor response and had "negligible cardiovascular toxicity."

To investigate further, they studied 20 patients with newly diagnosed, advanced prostate cancer. The tendency of their blood to coagulate was assessed before and after 12 months of treatment with estrogen patches.

Levels of coagulation factors were increased in some patients, but to a much lower extent than previously seen in patients given equivalent doses of oral estrogens, Abel's team found.

In an accompanying editorial, Dr. Larry Goldenberg of the University of British Columbia, Vancouver, points out that that estrogen patches also protect against osteoporosis -- another hazard for prostate cancer patients -- making the findings reported by Abel's group "compelling" and deserving of further study.

SOURCE: Journal of Urology, August 2005.