At least 20% of people who develop lung cancer are nonsmokers, according to Mayo Clinic physician Catherine Madaffari, M.D.
Notes on verification
Direct quote confirmed via Mayo Clinic News Network, and the 20% figure is corroborated by American Cancer Society and Yale Medicine, though some epidemiological studies cite slightly lower ranges (10-15%) depending on methodology. [tier=unverified indep_score=0.3 clusters=2 claim_tier=notable] [rescored 2026-09-15: curated origin-host map (PR #65); unclassified hosts no longer scored as aggregators]
Sources
- Anyone With Lungs Can Get Lung Cancer (seed:health_and_medicine)
- https://www.yalemedicine.org/conditions/lung-cancer-in-nonsmokers (corroboration)
- https://www.cancer.org/cancer/latest-news/why-lung-cancer-strikes-nonsmokers.html (corroboration)