Wildfires Up Risk for Patients with NSCLC

Data indicate that exposure to wildfires reduces overall survival (OS) rates of patients recovering from lung cancer surgery (JAMA Oncol 2023 Jul 27 [Epub ahead of print]). This phenomenon is present across the United States, especially in places where residential areas and vegetation comingle, known as the wildland–urban interface (WUI).

“The physical, psychological, and socioeconomic consequences posed by exposure to wildfires have a measurable impact on the survival of patients recovering from non–small cell lung cancer [NSCLC] surgery,” says study author Leticia Nogueira, PhD, MPH, of the American Cancer Society. Air pollution, contaminated soil and water, disruptions in care, and stress related to the fear for personal safety and the possible need to flee all weigh on patients.

“Furthermore, we used historical data for our analysis, meaning this is not theoretical. These hazards are here, will continue to grow with climate change, and threaten the health of people across the nation,” she adds.

Among the 466,912 patients in the study who had surgery for NSCLC between 2004 and 2019, those exposed to wildfire within 12 months of sur­gery experienced shorter OS. The sooner a patient was exposed to wildfire following discharge, the higher their chances of death. Patients exposed between 0–3 months, 4–6 months, and 7–12 months after surgery had a 43%, 39%, and 17% increased chance of dying, respectively, compared with patients not exposed to wildfire. Although the findings were statistically significant, even after controlling for sex, cancer stage, comorbidities, health insurance coverage, and geographic region, the study did not record relocation following surgery, duration of exposure, and smoking history.

The researchers note that although Western states more frequently experience large fires, people residing in the Southeast were found to be more frequently exposed to wildfires due to fires in nearby WUIs. They hypothesize that negative effects from exposure could be exacerbated by the region's lower income, as residents may have limited options to prevent or cope with exposure, such as buying air purifiers and masks or temporarily relocating.

Overall, individuals exposed to wildfire up to 3 months after discharge were more likely to live in rural areas, lack private health insurance, and reside in areas with lower income.

People living closer to areas likely to burn face a greater risk of exposure, but “wildfire smoke plumes can travel widely depending on weather conditions, so this is not always the case,” notes Sandrah P. Eckel, PhD, of the Keck School of Medicine at the University of Southern California in Los Angeles. Canadian wildfires, for example, have affected major urban areas in the Northeast this summer.

Although the study looked only at patients with NSCLC, the PM_2.5 particles found in wildfire smoke could cause an increase in risk for other cancer types, based on earlier research, says Yuming Guo, MD, PhD, of Monash University in Melbourne, Australia (PLoS Med 2022;19:e1004103).

Researchers and independent experts agree that educational programs about the dangers of wildfire and strategies to minimize risk for vulnerable populations are important, but they say that to reduce the risk to all people—not only those suffering from lung cancer—climate-change mitigation is urgent.

Furthermore, says study co-author Yang Liu, PhD, of the Rollins School of Public Health at Emory University in Atlanta, GA, “the health risks imposed by climate change can be complex, multifaceted, and sometimes unexpected. Care teams should be prepared for possible care interruptions, anxiety, and mental trauma experienced by their patients during fire seasons.” –Myles Starr

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