A Hitherto Unknown Advantage of Having Hot Flashes

Some women experience severe symptoms of menopause (cessation of menstrual periods) with severe symptoms, including hot flashes, while others go through menopause without any symptoms.  The difference appears to be associated with the level of estrogen – the lower the estrogen level in the body, the worse the symptoms.  That’s why hormone replacement therapy (HRT) is so successful in suppressing the symptoms.   But now a study has demonstrated an association between menopausal symptoms and breast cancer risk.  It’s published in the ‘online first’ version of Cancer Epidemiology Biomarkers & Prevention.    

Fred Hutchinson Cancer Research Center scientists interviewed 1,437 postmenopausal women in the Seattle area.  There were 988 of them who had been diagnosed with breast cancer and 449 who had not.  The women were asked about symptoms as they approached and entered menopause – intensity and frequency of hot flashes, night sweats, insomnia, vaginal dryness, irregular or heavy periods, anxiety, and depression.  The risks of different histological types of breast cancer were then calculated for different degrees of menopausal symptoms.

Analyses showed that, compared to the women who hadn’t experienced symptoms of menopause, women who had hot flashes and other symptoms had a 40% to 60% lower risk of developing the two most common forms of breast cancer – invasive ductal carcinoma and invasive lobular carcinoma.  This association was unchanged when adjustments were made for other known risk factors, such as obesity or the use of HRT.

This result might have been expected, based on the relationship between estrogen levels and both menopause symptoms and breast cancer.  However, it provides women who suffer severe menopausal symptoms with some solace – they’re less likely to have breast cancer than those without such symptoms.  And researchers into the causes of breast cancer have some additional confirmatory evidence for one mechanism.