Lung cancer is often linked to smoking, but recent decades have seen a significant rise in cases among non-smokers. This trend has led researchers to explore other risk factors such as air pollution, chemical exposure, and genetic predisposition.

In 2017, nearly 1.57 million men and over 900,000 women were diagnosed globally. Notably, 10% to 20% of lung cancer cases occur in people who have never smoked. Adenocarcinoma is the most common subtype, particularly among women.

Environmental pollution, especially exposure to fine particles like PM2.5 and PM10, increases lung cancer risk by causing chronic inflammation and mutations. Regions like East Asia and North Africa report the highest incidence rates. Radon gas, which can accumulate in poorly ventilated homes, is another significant environmental risk, even for non-smokers.

Genetic factors also play a key role. Mutations in genes such as EGFR, ALK, and KRAS have been identified in non-smokers, highlighting the importance of genetic screening, especially in those with a family history.

Lifestyle factors—including poor diet, obesity, and inactivity—can weaken the body’s natural defenses.

Advances in early detection, particularly low-dose CT scans, are crucial. However, broader screening guidelines for non-smokers are needed to improve early diagnosis and survival rates.