Genetics can play a role in lung cancer, though smoking and environmental exposures are the primary drivers.
- Inherited Genetic Mutations: Certain inherited gene mutations, like those in TP53 (Li-Fraumeni syndrome) or RB1, can increase lung cancer risk, but these are rare. They may predispose individuals to multiple cancers, including lung cancer, even without heavy smoking
- Somatic Mutations: More commonly, lung cancer involves acquired (somatic) mutations in genes like EGFR, KRAS, or ALK, which drive tumour growth. These are not inherited but occur in lung cells, often influenced by smoking or other carcinogens. In non-smokers, EGFR mutations are more frequent, especially in women and those of Asian descent
- Family History: Having a first-degree relative with lung cancer may increase your risk by 1.5–2 times, even after accounting for smoking. This suggests a genetic component, possibly involving multiple low-risk gene variants (polygenic risk)
- Non-Smoker Lung Cancer: About 15–20% of lung cancer cases occur in non-smokers, and genetic predispositions (e.g., EGFR mutations or rare inherited syndromes) are often implicated, alongside environmental factors like radon or secondhand smoke
- Genetic Testing: Molecular testing of tumours can identify actionable mutations for targeted therapies (e.g., EGFR inhibitors like osimertinib). Genetic counselling may be recommended for those with a strong family history or young-onset lung cancer
While genetics contributes, smoking remains the dominant risk factor. If you’re concerned about personal risk or family history, consult a doctor or genetic counsellor for tailored advice.
Useful links:
National Cancer Institute or American Lung Association.