Today’s Learning Center Highlight brings us to a frequently ignored aspect of lung cancer discussions: it goes beyond smoking.

While smoking remains the leading cause, up to 1 in 4 lung cancer cases globally occur in people who have never smoked. Today, nearly 20% of new diagnoses fall into this group, with a significant proportion affecting women. Notably, radon exposure is the leading risk factor for lung cancer among non-smokers, with air pollution and secondhand smoke also playing a role. ^{1, 2, 3}

Thousands of lung cancer patients each year are diagnosed without the “typical” risk profile, and frequently ineligible for lung cancer screening under the USPSTF guidelines.

For patients, this can be surprising.

For physicians and care teams, it reinforces a critical point: risk is broader, more complex, and often less visible than we assume.

Beyond Smoking, What Increases the Risk of Lung Cancer?

Lung cancer in people who do not smoke is influenced by a combination of environmental, biological, and genetic factors that are often overlooked: ^{4, 5, 6, 7}

• Environmental factors include air pollution, radon gas, and secondhand smoke
• Workplace carcinogens, such as asbestos, diesel exhaust, and industrial chemicals
• Certain genetic mutations like EGFR, ALK
• Underlying lung conditions or prior radiation exposure
• Exposure to cooking fumes, especially in spaces with poor ventilation

Recent studies also show that particulate matter (PM) air pollution with a diameter of as small as 2.5 micrometers (PM 2.5) or less can directly cause genetic mutations linked to lung cancer, particularly among never-smokers. ⁷

In summary, lung cancer risk is not determined by just a single behavior. It develops over a lifetime of different exposures and biological factors.

Why Is This Important?

One major challenge is that many of these patients fall outside traditional screening criteria, which are still largely based on smoking history. As a result:

• Early-stage lung disease might not be detected
• Incidental nodules may not always be closely monitored
• Patients at higher risk may not get the timely intervention they need

This is where the gaps in lung cancer care pathways begin to appear. For physicians, care teams, and patients, this often leads to:

• More manual tracking of information
• Patient data scattered and spread across multiple systems
• Less visibility into who needs timely follow-up

Linking Risk Factors to Real-World Patient Care

At Optellum, we focus not only on finding nodules early but also on making lung cancer risk clear and actionable throughout the whole lung cancer care pathway.

Our AI-enabled solutions, such as Virtual Nodule Clinic (VNC) with Lung Cancer Prediction (LCP) AI support physicians and care teams to:

• Identify patients who fall outside traditional screening groups, including those with incidental findings
• Risk stratify using imaging-based AI, rather than relying only on demographics or smoking history
• Prioritize patients who need to be quickly evaluated
• Ensure follow-up is clear, well-coordinated, and guideline-aligned

Explore our Learning Center to learn more about:

• Lung nodules: how they are assessed and followed over time.
• Lung cancer: key risk factors, the role of early diagnosis, and what NSCLC and SCLC mean in practice.
• Lung cancer care: how structured pathways and advanced tools can support earlier, more consistent decisions.

References

1. Cheng, Elvin S et al. “Lung cancer risk in never-smokers: An overview of environmental and genetic factors.” Chinese journal of cancer research = Chung-kuo yen cheng yen chiu vol. 33,5 (2021): 548-562. doi:10.21147/j.issn.1000-9604.2021.05.02
2. “Lung Cancer Among People Who Never Smoked.” Lung Cancer, 15 Oct. 2024 https://www.cdc.gov/lung-cancer/nonsmokers/index.html?utm_source
3. “A New Face of Lung Cancer Is Emerging: Young, Non-smoking Women.”The James – OSUCCC, cancer.osu.edu/news/a-new-face-of-lung-cancer-is-emerging-young non-smoking-women.
4. “Lung Cancer.Symptoms & Causes.” Https://Www.Mayoclinic.Org/Diseases-conditions/Lung-cancer/Symptoms-causes/Syc-20374620, 30 Apr. 2024.
5. “Lung Cancer Causes | Lung Cancer in Non-Smokers.” American Cancer Society www.cancer.org/cancer/types/lung-cancer/causes-risks-prevention/what-causes.html?utm_source.
6. Dubin, Sarah, and Daniel Griffin. “Lung Cancer in Non-Smokers.” Missouri medicine vol. 117,4 (2020): 375-379.
7. Deborah R. Caswell, Crispin Hiley, Cian Murphy, Loc Carlo Bao, Charles Swanton, Lung cancer in never smokers: from early detection to prevention, Trends in Cancer, 2026, ISSN2405-8033,https://doi.org/10.1016/j.trecan.2025.12.009