A growing number of people who have never smoked are being diagnosed with lung cancer — and women, particularly of Asian descent, are disproportionately affected. The BBC reports that while overall smoking rates are falling worldwide, up to one in five new lung cancer cases now occur in people who have never smoked.
Oncologist Andreas Wicki of the University Hospital Zurich said lung cancer in nonsmokers “is emerging as a separate disease entity” with unique genetic and environmental causes. Women who have never smoked are more than twice as likely as men to develop the disease, often tied to mutations in the EGFR gene. These mutations, common among Asian women, cause cells to grow uncontrollably. Hormonal differences, such as estrogen activity, may also heighten risk.
Environmental exposure plays a major role. Studies from the World Health Organization’s cancer agency found that outdoor air pollution is now the second-leading cause of lung cancer worldwide, after smoking. Fine particles known as PM2.5 — produced by vehicle exhaust, fossil fuels, and wildfires — are linked to nearly 200,000 lung adenocarcinoma cases annually, with the heaviest burden in East Asia. “Both air pollution and EGFR mutations are needed for tumors to grow,” said William Hill of London’s Francis Crick Institute.
Despite advances in targeted drugs that extend survival, experts warn that prevention and clean-air policies remain critical. As researcher Ganfeng Luo noted, “99% of the world’s population lives where air pollution exceeds WHO limits.”
See: “The mystery rise of lung cancer in non-smokers” (June 6, 2025)
