Inhaling wildfire-related air pollution may reduce the likelihood of survival among patients with non–small cell lung cancer (NSCLC), according to new findings presented by Singhal et al at the 2025 ASCO Annual Meeting (Abstract 10520).
Background
Wildfire-related air pollution contains particulate matter with a diameter of 2.5 μm or less (PM2.5) that are capable of getting deep into the lungs.
Study Methods and Results
In the study, investigators analyzed the outcomes of over 18,000 patients residing in California who were diagnosed with NSCLC between 2017 and 2020. They used advanced modeling to estimate daily air quality at patients’ home addresses and factored in data from satellites, weather models, smoke forecasts, and air quality monitors.
The investigators discovered that the patients who were exposed to more wildfire-related air pollution in the year following their cancer diagnosis were more likely to die from the disease. For instance, those who inhaled higher levels of PM2.5 had a 20% greater risk of mortality from lung cancer.
“The research tells us that there are small particles in the air that could make lung cancer worse,” suggested lead study author Surbhi Singhal, MD, an oncologist at the University of California, Davis Comprehensive Cancer Center.
In addition, the patients with stage IV NSCLC who had never smoked were particularly affected. Their mortality risk rose by 55% if they were exposed to high levels of air pollution.
Notably, the investigators found that patients with stage IV NSCLC with a history of smoking who were treated with immunotherapy experienced greater survival rates during days of extremely high PM2.5 toxin levels. These levels were likely caused by wildfire smoke instead of background air pollution. The trend indicated that smoke-related changes in the body may interact with certain treatments.
Conclusions
“As wildfires become more frequent and intense in California and other parts of the [United States], we need targeted health strategies to protect patients [with cancer] and others with serious health problems,” Dr. Singhal underscored. “These results highlight the urgent need to protect vulnerable populations living in wildfire-prone regions,” she concluded.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.
