PM2.5 and black carbon levels associated with increased mortality in lung cancer patients

Lung cancer is the leading cause of cancer mortality in the United States. Over recent years, lung cancer incidence among never-smokers has been rising. Additionally, heterogeneity in treatment responses among patients with lung cancer have not been fully elucidated. Outdoor air pollution (OAP) is a known lung carcinogen, but little is known about the effects of OAP on lung cancer survival and prognosis. Therefore, this study aimed to assess the association between OAP exposure and lung cancer survival. A retrospective cohort study was conducted by gathering patient and clinical data from a cohort of 8,793 non-small cell lung cancer (NSCLC) patients from the Montefiore Einstein Comprehensive Cancer Center (MECCC) in the Bronx, NY. Environmental exposure to OAP was estimated based on the patients' geo-coded addresses. Pollutants were estimated by combining Aerosol Optical Depth retrievals from different instruments with the GEOS-Chem chemical transport model. The data were calibrated to regional ground-based observations using a geographically weighted regression. Quantitative analyses were performed using Kaplan-Meier curves and Cox proportional hazard models. Stepwise regression model selection for confounding variables, including smoking, sex, age, histology, stage, treatment (transplant, surgery, chemotherapy, radiation), and other pollutants (NH 4 , organic matter, SO 4 ) was used. Exposure to >9ug/m 3 of PM2.5 and >median levels of Black Carbon at the time of diagnosis were associated with an 8% and 6% decrease in overall lung cancer survival, respectively (p<0.0001). PM2.5 was associated with decreased lung cancer survival by 5-9% in all sex, smoking, and histology groups (p<0.0001). Black Carbon was associated with a 4-9% decrease in lung cancer survival in male (p=0.01), female (p<0.0001), never (p=0.05) or ever (p<0.0001) smoker, and Adenocarcinoma (p<0.0001) subgroups. Consistent with previous studies, we observed an association between PM2.5 exposure and decreased lung cancer survival. Black Carbon, not tested in previous studies, was also associated with decreased lung cancer survival. Future research is needed to explore the relationship(s) between additional geospatially correlated exposures, OAP, and lung cancer survival.