Drop in breast cancer rate linked to decline in HRT use

Today's New England Journal of Medicine reports an 8.6 percent decline in U.S. breast cancer rates between 2001 and 2004, and connects that drop to fewer women using hormone replacement therapy to counter the symptoms of menopause.

NEJM's analysis of National Cancer Institute registries showed a sharp decline in 2003—after HRT use was linked to breast cancer risk—followed by a leveling off in 2004. The effect was particularly robust for post-menopausal women with estrogen-receptor-positive breast tumors (cancers that grow in response to estrogen).

And while some researchers argue that it's premature to attribute the decline to HRT (stopping HRT may have slowed the growth of some tumors, but they could show up in later years, for example), it's clearly been enough evidence to convince many women to say no thanks.

Hormones play an important role in the development of breast cancer, whether from HRT or hormone-disrupting chemicals (atrazine, bisphenol A, dibutyl phthalate, dioxin, organochlorine pesticides, polycyclic aromatic hydrocarbons and others). Elimination of this one hormone source meant 30,000 fewer women received a diagnosis of breast cancer over the course of the 2-year NEJM study; now imagine how many more women could be spared if we eliminate these other exposure sources.

(Read more coverage of today's HRT story from the Associated Press and the Los Angeles Times.)