SEATTLE, Jan. 26 (UPI) -- Women who suffer through hot flashes and other menopausal symptoms may have much lower risk of the most common forms of breast cancer, U.S. researchers say.
Senior author Dr. Christopher I. Li, a breast cancer epidemiologist in the Hutchinson Center's Public Health Sciences Division in Seattle, and colleagues say hormones such as estrogen and progesterone play an important role in the development of most breast cancers, and reductions in these hormones can impact the frequency and severity of menopausal symptoms.
"In particular we found that women who experienced more intense hot flushes -- the kind that woke them up at night -- had a particularly low risk of breast cancer," Li says in a statement.
The researchers interviewed 1,437 postmenopausal Seattle-area women, 988 of whom had been previously diagnosed with breast cancer and 449 of whom had not to serve as the control group, about perimenopausal and menopausal symptoms ranging from hot flashes, night sweats and insomnia to vaginal dryness, irregular or heavy menstrual bleeding, depression and anxiety.
The study, scheduled to be published in the February print issue of Cancer Epidemiology Biomarkers and Prevention, found a 40 percent to 60 percent reduction in the risk of invasive ductal and invasive lobular carcinoma -- the two most common types of breast cancer -- among women who experienced hot flashes and other symptoms even after factoring for obesity and hormone replacement therapy, both known to increase breast cancer risk.
