Lung cancer has always been framed as a smoker’s disease. But what if you’ve never smoked? Singapore’s own numbers are starting to complicate that picture. In a written parliamentary reply on 8 October 2026, the Ministry of Health (MOH) confirmed that “a 2026 modelling study based on local data indicates an increasing lung cancer incidence in never smokers in both males and females.”
The study behind that answer, published in The Lancet Regional Health, Western Pacific, used Singapore Cancer Registry data from 1968 to 2021. It found that lung cancer cases among female never-smokers rose by an average of 4.06% a year, and those among male never-smokers by 3.33% a year, even as overall male lung cancer rates fell. The only age group with a significant rise in female incidence was women aged 30 to 49, not older patients.
Key Takeaways
- A 2026 modelling study based on Singapore Cancer Registry data (1968 to 2021) found lung cancer incidence rising among never-smokers of both sexes, confirmed by MOH in Parliament on 8 October 2026.
- Female never-smoker cases rose 4.06% a year on average; male never-smoker cases rose 3.33% a year, even as men’s overall lung cancer rates declined.
- The rise in women was concentrated in the 30 to 49 age group, not older patients, challenging the assumption that lung cancer mainly affects older adults.
- MOH says PM2.5 exposure, including from transboundary haze, is linked to higher lung cancer risk in international studies, but usually only after long-term exposure; the effect of Singapore’s periodic haze specifically is not yet established.
- Low-dose CT screening is currently recommended only for current or former heavy smokers in Singapore, meaning most never-smoker cases fall outside existing screening guidelines.
What the Numbers Actually Show
The study drew on close to 53,000 lung cancer cases logged through Singapore’s Trusted Research and Real-World Data Utilisation and Sharing (TRUST) platform. Over the 53-year period, lung cancer incidence crept up among women overall while falling among men, narrowing a gap that had long made lung cancer look like a predominantly male disease. Broken down by smoking status, both never-smoking men and never-smoking women showed rising case numbers, alongside ever-smoking men, while the male decline was driven almost entirely by falling rates among smokers.
There is a silver lining: stage I diagnoses rose sharply in both sexes. This suggests more cases are being caught earlier, possibly through incidental findings on scans done for other reasons. Even so, stage IV, the most advanced and hardest to treat, remained the most common stage at diagnosis for both men and women. Earlier detection is improving, but late-stage disease is still the norm, not the exception.
Why Non-Smokers Get Lung Cancer At All
Doctors have identified several contributing factors in never-smokers, though no single explanation accounts for the full trend. Second-hand smoke exposure at home or work is one established risk. EGFR (epidermal growth factor receptor) mutations are also found in a large share of lung cancers in Asian patients who have never smoked, far more often than in non-smoking Western populations. These mutations can make targeted drug treatment an option. Researchers behind the 2026 study also point to emerging, less settled leads: genetic factors such as ERBB2 mutations and ALK gene rearrangements, reproductive and hormonal factors such as early childbirth or hormone replacement therapy, and early-life exposure to second-hand smoke or cooking fumes.
What about air pollution? MOH’s parliamentary answer notes that international research links PM2.5 exposure to higher lung cancer risk, typically after long-term exposure. Whether Singapore’s periodic haze episodes contribute to the local rise remains unclear. More environmental and health data need to be collected and compared over time. In short: air pollution is a plausible piece of the puzzle, not a confirmed cause of the local rise.
What This Means for Screening and Symptoms
Singapore’s current screening guidelines recommend low-dose CT scans only for current or former heavy smokers, a group defined by pack-years of smoking history. If you’ve never smoked, you fall outside that recommendation regardless of age or family history. That does not mean your risk is zero. MOH has said it will continue monitoring emerging evidence on whether screening should be extended to non-smokers, but had not announced a specific policy change as of its parliamentary reply.
If you’ve never smoked, particularly if you’re a woman in your 30s or 40s, don’t dismiss persistent symptoms because you don’t fit the stereotypical lung cancer risk profile. A cough lasting more than three weeks, unexplained breathlessness, chest pain or coughing up blood warrants medical assessment regardless of smoking history.
Frequently Asked Questions
Does this mean never-smokers should ask for a CT scan?
Not automatically. Low-dose CT screening in Singapore is currently recommended only for heavy smokers, since that is the group in which trials have shown it reduces deaths. Never-smokers with persistent symptoms should raise them with a doctor, who can decide whether imaging is warranted on a case-by-case basis.
Is this rise specific to Singapore, or happening elsewhere too?
Rising lung cancer among women and younger adults, including never-smokers, has also been reported more broadly across Asia over the past decade, alongside similar rises in thyroid and breast cancer, suggesting this is a regional pattern rather than one unique to Singapore.
Is second-hand smoke the main cause?
It’s one established risk factor, estimated to raise risk by roughly a quarter, but researchers are explicit that it does not explain the full picture, since many never-smoker patients have no clear history of heavy second-hand smoke exposure either.
Should I be more worried about haze because of this?
MOH has not confirmed a specific link between Singapore’s haze episodes and the rise in never-smoker lung cancer, noting that this kind of association typically only becomes clear after long-term data collection and correlation. General haze precautions remain sensible for respiratory health regardless, but this particular study does not establish haze as a confirmed cause.
The Bottom Line
Smoking history is not the whole story of lung cancer in Singapore. The rise among never-smokers, alongside the increase in incidence among younger women, challenges the idea that “I don’t smoke, so I’m not at risk”. The practical response is awareness, not panic: know the symptoms, don’t dismiss them because you’ve never smoked, and speak to a doctor if they persist. Seek prompt medical attention for coughing up blood or sudden breathlessness.
Editorial Note
This article is intended for general educational purposes only and does not constitute medical advice. Lung cancer risk, screening eligibility and treatment all depend on individual factors a doctor needs to assess directly. Consult a doctor if you have persistent respiratory symptoms, regardless of your smoking history, and seek prompt medical attention for coughing up blood or sudden breathlessness.
Sources
- Ministry of Health, Singapore. “Lung Cancer Trends Among Never-Smokers Over Past 10 Years, Assessment of Long-Term PM2.5 and Haze Exposure, and Environmental Data Collection by Singapore Cancer Registry.” MOH Newsroom, Parliamentary Q&A, 8 October 2026. https://www.moh.gov.sg/newsroom/lung-cancer-trends-among-never-smokers-over-past-10-years–assessment-of-long-term-pm2-5-and-haze-exposure–and-environmental-data-collection-by-singapore-cancer-registry-/
- Dela Cruz, J. “SG Sees Narrowing Male-Female Gap in Lung Cancer Incidence.” MIMS (CIMS), The Lancet Regional Health, Western Pacific, 2026. https://www.mims.com/india/news-updates/topic/sg-sees-narrowing-male-female-gap-in-lung-cancer-incidence