New Study Reaffirms HRT Link to Breast Cancer Rate Decline

Mar. 23 -- TUESDAY, July 24 (HealthDay News) -- Scientists have once again linked a drop in breast cancer rates from 2003 to 2004 to a parallel decrease in women's use of hormone therapy beginning in 2002.

The decline in breast cancer rates persisted even though mammography screening rates remained stable, said researchers at Kaiser Permanente, reporting in the August issue of the Journal of the National Cancer Institute.

"The message is pretty straightforward," said study lead author Dr. Andrew Glass, senior investigator at the Kaiser Permanente Center for Health Research in Portland, Ore. "If you need to take hormone therapy to block menopausal symptoms, do it for the shortest duration and the lowest dose."

"We now have a second observation that when we discontinue or decrease hormone therapy, we have a very significant drop in breast cancer incidence," added Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System in Baton Rouge, La. "This is another piece of information that I think women should use in determining whether or not they want to take hormone therapy. To me, it shows that combination therapy [estrogen plus progestin] does increase the incidence of breast cancer. Women need to take this into consideration."

Last December, a different set of researchers reported a precipitous drop in the incidence of breast cancer in 2003 and suggested that the downward trend was the result of millions of women discontinuing use of hormone replacement therapy.

The decline in the number of U.S. women taking hormone replacement therapy came after publication of the results of the landmark Women's Health Initiative (WHI) trial in 2002. That study, involving 16,608 participants, was halted after researchers found elevated health risks among HRT users, most notably for breast cancer and stroke.

Since then, a debate has continued over the utility and safety of hormone therapy, with health officials advising women to take HRT only when needed and for as short a period as possible.