Women who have experienced hot flushes appear to have a 50 percent lower risk of developing the most common forms of breast cancer, according to a recent study by researchers at Fred Hutchinson Cancer Research Center.
The protective effect, reported in the journal Cancer Epidemiology Biomarkers and Prevention, appears to increase along with the number 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," said researcher Christopher I. Li.
Li and colleagues suspected a link between menopause misery and decreased breast cancer risk because hormones such as estrogen and progesterone play an important role in the development of most breast cancers, and reductions in these hormones caused by gradual cessation of ovarian function can impact the frequency and severity of menopausal symptoms.
Menopausal symptoms occur as hormone levels fluctuate and drop, so Li hypothesized that women who experienced symptoms such as hot flushes and night sweats - particularly frequent and severe symptoms - might have a lower risk of breast cancer due to decreased estrogen levels.
Li found a 40 - 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 flushes and other symptoms. Interestingly, the association between such symptoms and decreased cancer risk did not change even after Li accounted for other factors known to boost breast cancer risk, such as obesity and use of hormone replacement therapy.
"While menopausal symptoms can certainly have a negative impact on quality of life, our study suggests that there may be a silver lining if the reduction in breast cancer risk is confirmed in future studies," Li said. "If these findings are confirmed, they have the potential to improve our understanding of the causes of breast cancer."
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Source: Fred Hutchinson Cancer Research Center