Regular aspirin use and breast cancer risk in US Black Women
Cette étude de cohorte incluant 59 000 participantes afro-américaines évalue l'effet protecteur de l'aspirine et du paracétamol sur le risque de cancer du sein
Background Epidemiologic studies have yet to provide consistent evidence to support a protective effect of aspirin and other non-steroidal anti-inflammatory drugs (NSAID) on the incidence of breast cancer. Objective We evaluated the relations of current use of aspirin, non-aspirin NSAIDs, and acetaminophen with breast cancer incidence in the Black Women’s Health Study. Methods Biennial follow-up of 59,000 study participants began in 1995. During 558,600 person-years of follow-up through 2007, 1,275 breast cancer cases were identified. Using Cox proportional hazards regression, we estimated incidence rate ratios (IRR) and 95% confidence intervals (CI) for associations of current and former use of aspirin, other NSAIDs, and acetaminophen with incident breast cancer. Results After adjustment for age, education, body mass index at age 18, physical activity, female hormone use, current smoking, and other NSAID use, the IRRs were 0.79 (95% CI = 0.66, 0.95) for current aspirin use and 0.68 (95% CI = 0.50, 0.92) for ≥5 years of aspirin use. Similar associations were observed for acetaminophen use. Conclusions Both aspirin and acetaminophen use were inversely associated with breast cancer incidence in the present study. Reasons for the association with acetaminophen use are unclear, given that acetaminophen has very weak anti-inflammatory effects.