Study Finds Genomic Evidence Linking Air Pollution to Lung Cancer in Never-Smokers

Lung cancer has long been thought of primarily as a smoker's disease, but as tobacco use has declined in many parts of the world, the proportion of lung cancer cases occurring in people who have never smoked has continued to rise. A study published in Nature adds genomic evidence that may help explain part of why.

Researchers found mutational signatures — patterns of DNA damage that can point toward a likely cause — in never-smoker lung tumors that resemble the kind of genomic damage associated with air pollution exposure, alongside other environmental factors. The findings are notable because tumors in never-smokers do not consistently display the classic smoking-related mutational signatures long used to link lung cancer to tobacco exposure.

The trend disproportionately affects women, particularly women of East Asian descent, and tends to be more prevalent in East Asian than in Western nations, a pattern researchers say points toward a combination of environmental exposure and possibly genetic susceptibility factors that remain under active investigation. Fine particulate air pollution (PM2.5) is separately classified as a carcinogen and has been independently linked to lung cancer incidence in prior epidemiological research.

Lung cancer in never-smokers is increasingly studied as a biologically distinct disease category. Read more on the research landscape for this specific group in our article library.