A new federal study has found that women who take estrogen and progestin after menopause increase their chances of getting breast cancer and also face a small increased risk of dying from this disease. The Women’s Health Initiative study, which involved 16,000 women who were followed for 11 years, found “that women who took the hormones were just as likely as those who did not to develop more difficult-to-treat tumors and were more commonly found with tumors that had begun to spread,” Washington Post reporter Rob Stein wrote. Dr. Rowan Chlebowski of the Los Angeles Biomedical Research Institute (who was the lead author of the Women’s Health Initiative Study) believes “hormones, especially progestin, stimulate the blood supply that feeds small tumors and causes them to grow – a process called angiogenesis,” the Los Angeles Times reported.
However, additional research is needed. The Los Angeles Times article pointed to a study published in 2009 that found that hormone therapy users did develop breast cancer at a young age than nonusers. However, the cancers were not as dangerous and survival rates were higher in hormone users.
Interestingly, breast cancer diagnoses dropped significantly after women stopped taking hormones based on earlier findings linking hormone therapy and breast cancer. “In 2002, more than 110 million prescriptions for hormones were filled; by 2009, the number had dropped to about 40 million, according to IMS Health, which tracks prescription drug sales,” Stein reported. “Breast cancer diagnoses subsequently started to drop. That appeared to help explain one of the biggest mysteries about breast cancer – why the number of cases rose steadily for decades: Hormone use probably played a key role, along with better detection by mammography and other factors.”
The latest findings from the Women’s Health Initiative study should be another cautionary signal to women who are considering taking hormones and to the doctors who are prescribing them. Earlier research has found that women taking hormones were more likely to die from lung cancer, as reported by the Los Angeles Times. Other studies have indicated that taking hormones can increase a women’s risk of ovarian and endometrial cancer, but could lower her risk of colorectal cancer.
Experts who were interviewed for the Washington Post story urged women and their doctors to give careful consideration to hormone replacement therapy. “Let’s not throw the baby out with the bath water. Hormonal symptoms can really be life-changing for many women – changing their ability to concentrate, their mood, their personality,” said Hugh Taylor, chief of reproductive endocrinology at Yale University, as reported in the Washington Post. “It can be really horrendous. Just because there is a very small risk associated with a therapy doesn’t necessarily mean we completely abandon it.” The experts recommend the lowest dosage for the shortest period of time for women who need the assistance of hormones.
Published On: October 25, 2010