New Breast Cancer Drug May Beat Tamoxifen

SAN ANTONIO -- Doctors say a newer class of drugs is showing better results in preventing the return of breast cancer than the more traditional drug, tamoxifen.

British researchers the drug, Arimidex, should now be the first-choice of treatment for most women who have had the disease. A five-year international study suggests it might be able to prevent 70 to 80 percent of the most common type of tumors that occur in women after menopause.

The older drug, Tamoxifen, works by blunting the effects of estrogen, a hormone that promotes the growth of about three-fourths of the tumors that occur in postmenopausal women. Arimidex, known generically as anastrozole, prevents the production of estrogen in the first place.

The new drug also showed fewer side effects, although bone fractures and joint pain were more common than among women given tamoxifen.

The study was funed by Arimidex's maker, AstraZeneca PLC, and involved nearly 2,000 American women and an additional 7,300 from 20 other countries. The findings are published in online by the journal The Lancet and were presented Wednesday at the San Antonio Breast Cancer Symposium.

The Lancet
San Antonio Breast Cancer Symposium