Breast Cancer Drug Femara Beats Tamoxifen
Better Survival Rates After Surgery and Menopause, Says Drugmaker
How the Drugs Work continued...
More than 8,000 women in 27 countries participated in the study. All had undergone breast cancer surgery and were postmenopausal. Their breast cancer was treated early; it hadn't spread beyond the breast and lymph nodes.
The women's tumors were dependent on the hormone estrogen to grow. About two-thirds of breast cancers are fueled by estrogen, says the ACS.
Typically, women take tamoxifen for about five years. About 500,000 U.S. women take tamoxifen and 80,000 join their ranks each year.
The women were studied for 26 months, on average. They were assigned to different treatment plans to see which treatment plan worked best to reduce the risk of the recurrence of breast cancer.
One group took tamoxifen or Femara for five years. Another group of women took tamoxifen for two years, followed by three years on Femara. A third group of women got the opposite approach - two years of Femara followed by three of tamoxifen.
The results showed that compared with tamoxifen, Femara cut the risk of recurrence of breast cancer by 19%.
Femara significantly increased survival free of breast cancer, especially reducing the risk of the spread of breast cancer to distant parts of the body.
Women taking Femara were more likely to have bone fractures. Higher cholesterol was also more common with Femara, though the effect was "usually mild," says Novartis. Heart attack and stroke were rare with both drugs but occurred slightly more often with Femara, says Novartis. Femara should not be taken during pregnancy.
Tamoxifen also had side effects including clotting, vaginal bleeding, and changes in the womb's lining (the endometrium).