标题：Breast cancer risk in relation to ambient concentrations of nitrogen dioxide and particulate matter: results of a population-based case-control study corrected for potential selection bias (the CECILE study)
摘要：Background There is only scant evidence that air pollution increases the risk of breast cancer. Objectives We investigated this relationship for three air pollutants: nitrogen dioxide (NO 2 ) and particulate matter with an aerodynamical diameter below 10 µm (PM 10 ) and 2.5 µm (PM 2.5 ). Methods We conducted a population-based case-control study on breast cancer in two French départements , including 1,229 women diagnosed with breast cancer in 2005–2007 and 1,316 control women frequency-matched on age. Concentrations of NO 2 , PM 10 and PM 2.5 at participants’ addresses occupied during the last 10 years were assessed using a chemistry transport model. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using multivariable logistic regression models where each woman was assigned a weight depending on her probability of selection into the study. Results The OR for breast cancer per 10-µg/m 3 increase in NO 2 was 1.11 (95% CI, 0.98, 1.26), and 1.41 (95% CI 1.07, 1.86) in the highest exposure quintile (Q5), compared to the first. The ORs per 10-µg/m 3 NO 2 did not markedly differ between pre- (OR 1.09, 95% CI 0.89, 1.35)) and post-menopausal women (OR 1.14, 95% CI 0.97, 1.33)), but the OR was substantially higher for hormone-receptor positive (ER /PR ) breast tumor subtypes (OR 1.15, 95% CI 1.00, 1.31) than for ER–/PR– tumors (OR 0.95, 95% CI 0.72, 1.26). Breast cancer risk was not associated with either PM 10 (OR per 1 µg/m 3 1.01, 95% CI, 0.96, 1.06) or PM 2.5 (OR per 1 µg/m 3 1.02, 95% CI 0.95, 1.08), regardless of the menopausal status or of the breast tumor subtype. Discussion Our study provides evidence that NO 2 exposure, a marker of traffic-related air pollutants, may be associated with an increased risk of breast cancer, particularly ER /PR tumors.
关键词：Air pollution ; Breast cancer ; Menopausal status ; Breast cancer subtypes ; Case-control study
