Menopausal symptoms may point to lower breast cancer risk

Women who experience menopausal symptoms such as hot flushes may have a lower risk of breast cancer, especially if the symptoms are severe, a new study from the Fred Hutchinson Cancer Research Center, Seattle, Washington, suggests.

Investigators interviewed 1,437 postmenopausal women, 988 of whom had been diagnosed with breast cancer and 449 of whom had not (the controls). They asked about perimenopausal and early menopausal symptoms such as intensity and frequency of hot flushes, night sweats, insomnia, vaginal dryness, irregular and heavy periods, anxiety, and depression.

The study concluded that women who have hot flushes and other symptoms may have about a 50% lower risk of developing the 2 most common forms of breast cancer-invasive ductal and invasive lobular carcinoma-than postmenopausal women who have never experienced such symptoms. The 40% to 60% lower risk of invasive ductal and invasive lobular carcinoma among women who experienced menopausal symptoms was unaffected by other risk factors for breast cancer, such as obesity and hormone replacement therapy.

“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,” says lead author Christopher I. Li, MD. Women who had severe hot flushes were at lower risk than women who had symptoms other than hot flushes with awakening and women who had hot flushes without perspiration. Risk tended to decrease as the number of symptoms increased but didn’t seem to be affected by the type of symptom.

The authors caution that because their study is the first to examine the association between symptoms and cancer risk, their results require confirmation. Their research was published online January 6 by Cancer Epidemiology Biomarkers and Prevention.