Lung Cancer Can Occur Even Without Smoking: Doctors Explain the Reasons

Smoking is one of the leading risk factors for lung cancer, but not every smoker develops the disease. Likewise, some people who have never smoked are also diagnosed with lung cancer. Researchers say this difference may be linked not only to smoking habits but also to genetic factors and the body's ability to repair DNA damage. Cigarette smoke can harm DNA in lung cells, but individuals with stronger DNA repair mechanisms may be better equipped to prevent damaged cells from turning cancerous. In addition, inherited genetic traits can influence how the body responds to DNA damage, meaning two people exposed to the same amount of smoke may face different levels of risk.

Experts also point out that lung cancer can develop in non-smokers due to factors such as genetic susceptibility, air pollution, and long-term exposure to secondhand smoke. Studies suggest that reduced DNA repair capacity may increase the likelihood of harmful mutations accumulating in cells, raising cancer risk. These findings are important because they could help scientists develop more personalized screening methods in the future by considering both smoking history and genetic risk factors. While smoking remains the biggest risk factor, non-smokers should not assume they are completely protected. Persistent cough, breathing difficulties, or chest pain should always be evaluated by a healthcare professional.