Lung cancer in people who have never smoked: what the evidence now shows
Lung cancer has long been understood as a disease of smoking. That understanding is no longer complete. Cases in people who have never smoked are rising, the disease behaves differently, and the systems built to find lung cancer were not designed for this group. As one of the field’s leading scientists puts it, the evidence points to a genuine absolute increase in these cases.
The short version
Lung cancer in people who have never smoked is now among the most common causes of cancer death worldwide.
The rise is real, not simply a side effect of falling smoking rates.
It is increasingly recognised as a biologically distinct disease, with different drivers and different treatment needs.
Known risk factors include air pollution, radon, secondhand smoke and certain workplace exposures.
Because screening is built around smoking history, these cancers are often found late, when outcomes are poorer.
Can you get lung cancer if you have never smoked?
Yes. While smoking remains the leading cause of lung cancer, a significant share of cases occur in people who have never smoked. Estimates vary by region. In the United States, people who have never smoked account for around one in eight lung cancer cases, while in parts of Asia the figure is 30% or more. Considered on its own, lung cancer in people who have never smoked would rank among the leading causes of cancer death globally, and it is now described as the fifth most common worldwide.
The point is simple and worth stating plainly. Anyone with lungs can develop lung cancer.
Why are cases rising?
As smoking declines, you would expect lung cancer in people who have never smoked to make up a larger proportion of diagnoses. But the change appears to be more than proportional.
Speaking in a 2026 feature in Nature, Professor Charles Swanton of the Francis Crick Institute described evidence of a genuine absolute increase in cases of lung cancer in people who have never smoked. In other words, the actual number of people affected is going up, not just their share of the total. The reasons are still being worked out, but the trend is now clear enough that clinicians and researchers are treating it as a distinct problem in its own right.
What causes lung cancer in people who have never smoked?
There is no single cause. Several environmental and biological factors are involved, and research is still developing.
Air pollution is among the most significant known risk factors. Outdoor air pollution has been classified as a Group 1 carcinogen, the highest category, since 2013. A major 2026 review for the Union for International Cancer Control attributed more than 434,000 lung cancer cases each year worldwide to air pollution, and found that long-term exposure to fine particulate matter raises overall cancer risk. Professor Swanton’s own earlier research showed how air pollution can trigger lung cancer in people who have never smoked, by acting on cells that already carry dormant mutations. We have looked at this evidence and its uneven impact across the continent in our piece on air pollution and lung cancer in Europe, and at the health inequalities involved when Lung Cancer Europe attended an ERS event on air pollution and health inequalities.
Other established risk factors include radon gas, secondhand smoke, and occupational exposures such as silica and asbestos. A family history of lung cancer also raises risk, pointing to inherited genetic susceptibility in some people.
Emerging questions continue to be raised about other environmental exposures, including the role of plastics, which we examined in new evidence on plastics and lung cancer.
Is it a different disease?
Increasingly, the evidence says yes. Lung cancer in people who have never smoked is now recognised as a biologically distinct entity, not simply the same disease without the cigarettes.
The tumours tend to carry different genetic drivers from lung cancer linked to smoking. Alterations in genes such as EGFR and ALK are far more common, and adenocarcinoma is the predominant type. This affects treatment directly, because many of these drivers can be matched to targeted therapies, which makes accurate molecular testing at diagnosis especially important. It also helps explain why a one-size-fits-all model of lung cancer no longer holds.
Who is most at risk?
Lung cancer in people who have never smoked affects women disproportionately. Women who have never smoked are more than twice as likely to develop lung cancer as men who have never smoked, and they are more likely to carry the driver mutations described above. Cases are also being seen in younger people, often diagnosed at a later stage. We set out the full picture, including new findings from the world’s largest oncology meeting, in lung cancer in women: what ASCO 2026 tells us.
The reasons for the sex difference are not fully understood and remain an active area of research, spanning biology, hormonal factors and unequal exposure to indoor air pollution from cooking.
Why is it often found late?
This is where the system falls short. Lung cancer screening is built around smoking history, using criteria developed largely from data on older people with a long history of smoking. Someone who has never smoked rarely qualifies, even when other risk factors are present.
The consequences are predictable. Symptoms can be attributed to other causes, referral is slower, and the cancer is more likely to be found at an advanced stage, when it is harder to treat and outcomes are poorer. Organised screening also remains limited across much of Europe, and where it exists it follows the same smoking-based eligibility. The result is a growing group of people who fall outside the safety net entirely.
What needs to change in Europe?
Three things follow from the evidence.
First, recognition. Lung cancer in people who have never smoked needs to be understood and counted as a distinct and rising disease, with the research funding and data collection that reflect it. European data, in particular, is needed to understand who is affected here.
Second, screening that fits the evidence. Eligibility based on smoking history alone systematically misses people at genuine risk. Reassessing those criteria is a necessary step.
Third, air quality treated as a lung cancer issue. The link between pollution and lung cancer is no longer in doubt, and the burden falls unequally across the continent. Clean air policy is cancer prevention policy.
At Lung Cancer Europe, we believe people living with lung cancer, and those at highest risk, must be part of these conversations. The evidence is clear. What is needed now is the will to act on it.
FAQS
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Yes. Smoking is the leading cause, but a significant proportion of lung cancer cases occur in people who have never smoked, and the number is increasing.
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In important ways, yes. It is now recognised as biologically distinct, more often driven by genetic alterations such as EGFR and ALK, and more common in women and in adenocarcinoma form.
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There is no single cause. Air pollution, radon, secondhand smoke, certain occupational exposures and inherited genetic susceptibility are all recognised risk factors.
Why is lung cancer in people who have never smoked often diagnosed late?
Screening and referral are built around smoking history, so people who have never smoked frequently do not qualify and their symptoms may be attributed to other causes, leading to later diagnosis.
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Women are affected disproportionately, with women who have never smoked more than twice as likely to develop lung cancer as men who have never smoked. Cases are also seen in younger people.