Lung and upper aero-digestive tract cancers and exposure to PM2.5 in the ICARE study (France)

Abstract

BACKGROUND AND AIM: Fine particulate matter (PM2.5) was classified as carcinogenic by the International Agency for Research on Cancer, especially for lung cancer. Nevertheless, it is not known whether the association with lung cancer differs by histological subtype. Little is known on the association with upper aero-digestive tract (UADT) cancers. Our aim was to study association between exposure to PM2.5 and lung and UADT cancers and their different subtypes and sub-sites. METHODS: We conducted a population-based case-control study in 10 French departments in 2001-2007, including 2,684 lung cancer cases, 1,985 UADT cancer cases and 3,481 controls frequency-matched on age and study area. Concentration of PM2.5 at the participants’ address during the 10 years before recruitment was assessed using a chemistry transport model. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using multiple logistic regression models adjusted for the relevant confounders. Analyses were conducted separately for the different histological lung cancer subtypes, and UADT sub-sites. RESULTS:The OR per 1 µg/m3 increase in PM2.5 for lung cancer was 1.03 (95% CI, 1.00, 1.07). Odds ratio was 1.24 (95% CI, 0.95, 1.62) in the highest exposure quintile, compared to the first. The ORs per 1 µg/m3 were slightly higher for squamous cell carcinoma (783 cases, OR 1.04 (95% CI, 1.01, 1.07)) and small cell carcinoma (374 cases, OR 1.04; 95% CI, 1.00, 1.07), than for adenocarcinoma (1017 cases, OR 1.02; 95% CI, 0.99, 1.05)). The OR per 1 µg/m3 increase in PM2.5 of the UADT cancer was 0.99 (95% CI, 0.95, 1.03), and no difference by UADT sub-site emerged in our data. CONCLUSIONS:The effect of PM2.5 on lung cancer risk may differ by histological subtype. No association with UADT cancer was observed. KEYWORDS: Cancer, Lung, Upper aero-digestive tract, Air pollution, Particulate matter, Case-control