A new study in the Proceedings of the National Academy of Sciences shows how smoking sets the stage for lung cancer. Researchers found that chronic smoke exposure damages lung tissue and creates distinct stem cell states. These changes help genetic mutations drive cancer, proving that inflammation is a key spark.

Na Wang, Raksha Padaki, Sara-Jayne Thursby and Michelle Vaz, ‘Chronic Cigarette Smoke Exposure Induces Distinct Stem Cell States Driving Genetic Driver-specific Non-small Cell Lung Cancer Subtypes’, Proceedings of the National Academy of Sciences, Vol. 123, Issue No. 42, October 5, 2026

Oncologists have long wrestled with a conundrum. Healthy human tissue often carries mutations that can drive cancer, but the tissue itself does not develop tumours. Clearly, a genetic spark alone is not enough. At the same time, chronic inflammation from smoking profoundly damages lung tissue long before any definitive cancer-causing mutations even take root.