New Delhi, July 31 -- Smoking remains the leading cause of lung cancer. But a growing number of people who have never smoked are now being diagnosed with the disease. In India, non-smokers account for an estimated 40 to 50% of all lung cancer cases, and some studies put the figure among Indian women as high as 83%. This has pushed doctors to look beyond the usual risk factors. Genetics is now part of that picture, helping explain why some people develop lung cancer despite no smoking history, and opening up options for earlier detection and more targeted drug treatment.

Can your genes increase disease risk?

Your genes carry the instructions that help cells grow, repair themselves, and function normally. Sometimes, variations or mutation...