Ambient fine particulate matter and breast cancer incidence in a large prospective US cohort
Menée aux Etats-Unis auprès de 196 905 femmes, cette étude analyse l'association entre des estimations à 5 et 10 ans de l'exposition aux polluants atmosphériques (PM2,5) et le risque de cancer du sein (15 870 cas)
Fine particulate matter (PM2.5) has been inconsistently associated with breast cancer incidence, however few studies have considered historic exposure when levels were higher.Outdoor residential PM2.5 concentrations were estimated using a nationwide spatiotemporal model for women in the NIH-AARP Diet and Health Study, a prospective cohort located in 6 states (California, Florida, Louisiana, New Jersey, North Carolina, and Pennsylvania) and 2 metropolitan areas (Atlanta, Georgia, and Detroit, Michigan) and enrolled in 1995-1996 (N = 196,905). Annual average PM2.5 concentrations were estimated for a 5-year historical period 10 years prior to enrollment (1980-1984). We used Cox regression to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the association between a 10 µg/m3 increase in PM2.5 and breast cancer incidence overall and by estrogen receptor (ER) status and catchment area.With follow-up through 2017, 15,870 breast cancer cases were identified. A 10ug/m3 increase in PM2.5 was significantly associated with overall breast cancer incidence (HR = 1.08, CI: 1.02-1.13). The association was evident for ER + (HR = 1.10, 95% CI : 1.04-1.17), but not ER- tumors (HR = 0.97, CI: 0.84-1.13; p-heterogeneity = 0.3). Overall breast cancer HRs were >1 across the catchment areas; ranging from a HR = 1.26 (CI: 0.96-1.64) for North Carolina to a HR = 1.04 (CI: 0.68-1.57) for Louisiana (p-heterogeneity = 0.9).In this large U.S. cohort with historical air pollutant exposure estimates, PM2.5 was associated with risk of ER+ breast cancer. State-specific estimates were imprecise but suggest that future work should consider region-specific associations and the potential contribution of PM2.5 chemical constituency in modifying the observed association.