QuotePublished: December 26, 2006
When researchers reported recently that a precipitous drop in breast cancer rates might be explained by a corresponding decrease in the use of hormones for menopause, women reacted with shock, anger and, in some cases, profound relief that they had never taken the drugs.
But many also had questions. How certain were scientists that the hormones were responsible? How could stopping hormones have such an immediate and pronounced effect? And how much did scientists really know about the biology of breast cancer and hormones?

The data seemed clear enough. In 2003, after climbing for almost seven decades, the breast cancer rate fell for the first time in the United States, and it fell sharply. Over all, the incidence of newly diagnosed breast cancer dropped 7 percent, and it dropped 15 percent among women with cancers whose growth is fueled by estrogen.