Lung cancer in non-smokers: risks that appear unexpectedly

Here's a statistic that challenges preconceived notions: lung cancer is no longer solely linked to smoking. In France, around 40,000 new cases are diagnosed each year, and among them, nearly one in ten patients has never smoked. Among women, the proportion of non-smokers affected even rises to between 30% and 40%, while it hovers around 10% among men.

This isn't a complete reversal; tobacco remains the overwhelming majority of causes, but it's enough to remind the reader that the disease has many faces. Globally, lung cancer in non-smokers has even become the fifth leading cause of cancer death, a ranking that speaks for itself.

Radon, dirty air, work: the silent culprits

Behind these cases, three factors keep recurring, like unseen guests. First, air pollution, a known carcinogen, with its fine particles and nitrogen oxides that accumulate over the years, without dramatic symptoms, just a slow build-up. Second, radon, a naturally occurring radioactive gas, which can concentrate in poorly ventilated homes, especially in certain areas like the Massif Central, Brittany, the Vosges Mountains, or Corsica—a domestic risk that is still too often underestimated. Finally, occupational exposures: asbestos, silica, diesel fumes, solvents—everything that is breathed in on a construction site or in a workshop, sometimes without the connection being made twenty years later, and with underreporting frequently mentioned.

Medicine, for its part, is refining the profile: EGFR, ALK, and KRAS mutations… in some non-smokers, these markers guide more targeted treatments and sometimes earlier diagnosis, a sign that "lung cancer" is no longer a monolithic entity. One undeniable, almost self-evident truth remains: prevention isn't just about refusing cigarettes; it also lies in the air we breathe and the walls that shelter us—an area where the coming years will be crucial.