Analgesics lowered risk for breast, ovarian cancers in postmenopause

Regular use of aspirin or other analgesics may decrease estrogen levels in postmenopausal women and contribute to a decreased risk for breast or ovarian cancers, study findings suggested.

Researchers assessed the association between aspirin, non-aspirin nonsteroidal anti-inflammatory drugs, and acetaminophen use and sex steroid hormone concentrations among 740 postmenopausal women. All were included in the Nurses’ Health Study. Between 1989 and 1990, the mean age of the cohort was 61.5 years. Women were, on average, slightly overweight and moderately physically active.

Regular use of aspirin — more than once per week — was more common (32%) among the women compared with regular use of acetaminophen (17.3%) or non-aspirin NSAIDs (19.1%) during 1990.

The researchers reported no association between days of use per month and hormone levels in 1990 (P<.09 for all). However, they observed significant inverse trends between the estimated number of aspirin used per month during 1988 and concentrations of estrone (P=.04) and estrone sulfate (P=.03).

Women who used NSAIDs at least 15 days per month had lower levels of estradiol vs. those who did not use NSAIDs (P=.03), according to analyses of total NSAID use in 1990.

Moreover, the frequency of analgesic use in 1990 was inversely associated with concentrations of estradiol (P=.001), free estradiol (P=.01), estrone sulfate (P=.03) and estradiol to testosterone ratio (P=.04) during 1990.

Given previous findings indicating an inverse association between analgesic use and risk for breast or ovarian cancers, researchers called for additional studies “to confirm this association and to determine whether the decrease in estrogen concentrations due to analgesic use translates to a lower risk for breast or ovarian cancer.”

Gates MA. Cancer Epidemiol Biomarkers Prev. 2010;19:1033–1041.