Association of Wildfire Exposure While Recovering From Lung Cancer Surgery With Overall Survival

Abstract

With a changing climate, wildfire activity in the US has increased dramatically, presenting multifaceted and compounding health hazards. Individuals discharged from the hospital following surgical resection of non-small cell lung cancer (NSCLC) are potentially at higher risk from wildfires' health hazards. To assess the association between wildfire exposure and postoperative long-term overall survival among patients with lung cancer in the US. In this cohort study, individuals who underwent curative-intent NSCLC resection between January 1, 2004, and December 31, 2019, were selected from the National Cancer Database. Daily wildfire information was aggregated at the zip code level from the National Aeronautics and Space Administration Fire Information for Resource Management System. The data analysis was performed between July 19, 2022, and April 14, 2023. An active wildfire detected at the zip code of residence between 0 and 3, 4 and 6, or 7 and 12 months after NSCLC surgery. Overall survival was defined as the interval between age at hospital discharge and age at death, last contact, or study end, whichever came first. Cox proportional hazards were used for estimating hazard ratios (HRs) adjusted for sex, region, metropolitan category, health insurance type, comorbidities, tumor size, lymph node involvement, era, and facility type. A total of 466 912 individuals included in the study (249 303 female and [53.4] and 217 609 male [46.6%]; mean [SD] age at diagnosis, 67.3 [9.9] years), with 48 582 (10.4%) first exposed to a wildfire between 0 and 3 months, 48 328 (10.6%) between 4 and 6 months, and 71 735 (15.3%) between 7 and 12 months following NSCLC surgery. Individuals exposed to a wildfire within 3 months (adjusted HR [AHR], 1.43; 95% CI, 1.41-1.45), between 4 and 6 months (AHR, 1.39; 95% CI, 1.37-1.41), and between 7 and 12 months (AHR, 1.17; 95% CI, 1.15-1.19) after discharge from the hospital following stage I to III NSCLC resection had worse overall survival than unexposed individuals. In this cohort study, wildfire exposure was associated with worse overall survival following NSCLC surgical resection, suggesting that patients with lung cancer are at greater risk from the health hazards of wildfires and need to be prioritized in climate adaptation efforts.