I’m an oncologist. Here’s what non-smokers need to know about lung cancer

Opinion byMikkael A. SekeresWashington Post·18 Oct, 2026 11:00 PM6 mins to readDr Mikkael A. Sekeres is the chief of the division of haematology and professor of medicine at the Sylvester Comprehensive Cancer Center, University of Miami.Lung cancer in non-smokers is intrinsically a different disease than in smokers. Image / GettyI always thought smoking was the main cause of lung cancer. What can lead a non-smoker to end up with lung cancer? This week, the Vatican confirmed that a lung nodule on Pope Leo XIV’s right lung was early-stage pulmonary adenocarcinoma, a subtype of non-small cell lung cancer. , along with the whole lower lobe of his right lung, during surgery. The pope is not known to be a smoker, though he does have a family history of other cancers – both of his parents died of cancer, and his brother is currently being treated for blood cancer.