Yesterday, researchers stated that women who use post-menopausal combination (estrogen-progestin) replacement therapy have about twice the risk of contracting and dying from aggressive breast cancers than those who pass up the treatment. The results were published in this week’s edition of the Chicago-based JAMA, Journal of the American Medical Association, a highly respected medical weekly known for its peer-reviewed original findings and informed editorial opinion (JAMA. 2010;304(15):1684-1692). A companion study of estrogen alone did not show same results.
Previous studies had suggested that tumors fueled by hormone therapy were less aggressive and easier to treat. The analysis reported today examined the charts of more than 16,600 women aged 50 to 79 taking part in the U.S.-funded Women’s Health Initiative. This is the first analysis to connect the hormone replacement therapy, which has been marketed in several forms, including tablets, implants, skin gels and patches, to increased mortality from breast tumors.
When scientists linked estrogen replacement therapy (Premarin) to the risk of endometrial cancer in the 1970s, Wyeth, the drug’s manufacturer, added another artificial hormone to reduce the uterine cancer risk of taking estrogen alone. The new drug was marketed as Prempro. Pfizer took over Wyeth last year, to become the world’s largest pharmaceutical company. Premarin and Prempro delivered $260 million for Pfizer in the second quarter of 2010.
“As opposed to the prevailing thought of two years ago, that cancers associated with estrogen plus progesterone would be favorable and not much of a problem, we are actually showing they are associated with an increased risk of death from breast cancer,” Dr. Rowan Chlebowski of the Los Angeles Biomedical Research Institute, who led the study, said in a telephone interview with Reuters.
The Wall Street Journal cited Judi Chervenak, an associate clinical professor of obstetrics-gynecology and women’s health at Montefiore Medical Center in New York, as saying that she advises women first to see if lifestyle changes, such as limiting caffeine, exercising, and deep-breathing or yoga can help them with the transition to menopause, rather than hormone therapy.
Last year The Lancet, Britain’s premier medical journal, reported that HRT pills also raise the risk of dying from lung cancer. About the two findings, Bloomberg News quoted lead investigator Chlebowski as saying, “You really don’t want to be taking a medication that increases the two leading causes of cancer death in women, unless you really have to.”