Title: Long-term PM2.5 exposure before diagnosis is associated with worse outcome in breast cancer.

Authors: Prada, Diddier; Baccarelli, Andrea A; Terry, Mary Beth; Valdéz, Leonora; Cabrera, Paula; Just, Allan; Kloog, Itai; Caro, Haydee; García-Cuellar, Claudia; Sánchez-Pérez, Yesennia; Cruz, Rodrigo; Diaz-Chávez, Jose; Cortés, Carlo; Pérez, Delia; Meneses-García, Abelardo; Cantú-de-León, David; Herrera, Luis A; Bargalló, Enrique

Published In Breast Cancer Res Treat, (2021 Jul)

Abstract: PURPOSE: Increasingly epidemiological evidence supports that environmental factors are associated with breast cancer (BC) outcomes after a BC diagnosis. Although evidence suggests that air pollution exposure is associated with higher mortality in women with BC, studies investigating potential mechanisms have been lacking. METHODS: We evaluated women with BC (N = 151) attended at the National Cancer Institute-Mexico from 2012 to 2015. We calculated 1-year average exposures to particulate matter < 2.5 μm (PM2.5) at home address before diagnosis. We used linear and logistic regression models to determine the associations between PM2.5 exposure and BC aggressiveness (tumor size, molecular phenotype). RESULTS: Average annual PM2.5 exposure of this population was 23.0 μg/m3 [standard deviation (SD)]: 1.90 μg/m3]. PM2.5 levels were positively correlated with tumor size at diagnosis (r = 0.22; p = 0.007). Multivariable linear models had a similar inference [risk ratio (RR): 1.32; 95% confidence interval (95% CI): 1.04, 1.674]. We did not observe differences in this association by age or menopause status. Further, women with triple-negative BC (TNBC) had significantly higher PM2.5 levels compared with other phenotypes (p = 0.015). Multivariable-adjusted logistic regression models assessing the association between PM2.5 and tumor size had a similar inference (RR 1.41; 95% CI 1.05, 1.89) overall for all ages and also for women who were ≤ 50 years old at diagnosis (RR 1.63; 95% CI 1.036, 2.57). CONCLUSIONS: Our findings suggest a significant association between long-term PM2.5 exposure and BC aggressiveness based on tumor size and phenotype, as well as a worse outcome.

PubMed ID: 33683522

MeSH Terms: Air Pollutants*/adverse effects; Air Pollutants*/analysis; Air Pollution*/adverse effects; Air Pollution*/analysis; Breast Neoplasms*/diagnosis; Breast Neoplasms*/epidemiology; Environmental Exposure/adverse effects; Environmental Exposure/analysis; Female; Humans; Mexico; Middle Aged; Particulate Matter/adverse effects; Particulate Matter/analysis