Lung Cancer Risk in Non-Smokers: Awareness and Genetic Testing

Lung cancer affects up to 25% of non-smokers, so persistent symptoms and genetic testing are key for early detection and treatment.

Dr. Ioana Bonta, adjunct clinical assistant professor at Morehouse School of Medicine, explains that lung cancer affects more than just smokers; up to 25% of patients have never smoked.

Misconceptions can delay diagnosis, so persistent symptoms like a lingering cough should never be ignored. Environmental exposures, including secondhand smoke, radon, asbestos, and air pollution, also increase risk.

Genetic testing is critical in guiding treatment, especially for advanced-stage disease. Identifying actionable mutations, such as EGFR, allows for targeted therapies that reduce side effects and improve survival. Even for patients diagnosed at later stages, personalized treatment combined with supportive care can enhance quality of life.

CURE: Lung cancer is often perceived as a smoker's disease. How has this perception impacted the diagnosis and treatment of non-smokers who develop the cancer?

Bonta: Lung cancer, as you said, is still perceived as a smoking-related cancer, a smoker’s disease, and that perception has a lot of impact in many ways. First of all, because people think, “You smoke, hence you’re at high risk of getting cancer; you don’t smoke, so you’re not at risk.” We can actually miss some patients who are diagnosed with lung cancer but have never smoked. So, the first thing to know is that lung cancer can affect everyone, not just smokers. In fact, according to the American Cancer Society, up to 25% of patients diagnosed with lung cancer have never smoked.

It’s important for healthcare providers, but also for patients, to recognize symptoms. If you have a cough that doesn’t go away, don’t disregard it. Be your own advocate and talk to your primary care physician. Cancer can happen to non-smokers.

This perception also affects diagnosis and treatment. For example, someone may have a calcium coronary score (a type of CT scan for heart health) and an incidental small nodule is found in the lung. But because the person doesn’t smoke, they or their doctor may dismiss it, thinking, “It can’t affect me.” Awareness is key because lung cancer can affect anyone.

Other risk factors include no direct or secondhand smoking, but exposure to secondhand smoke can still be significant. For instance, our mutual friend Ryan worked as a flight attendant back when smoking was allowed on planes. Even without smoking herself, that exposure put her at higher risk.

Pipe and cigar smoking also count as exposure, as does radon gas, which is released from the soil and can accumulate indoors; it’s the second leading cause of lung cancer in the U.S. I encourage everyone to test their homes for radon. Asbestos exposure, though less common now, still increases risk, especially among smokers. Certain organic chemicals, radiation, and air pollution (including diesel exhaust) also increase risk, particularly for people with lung sensitivities.

Could you explain the significance of genetic testing in guiding treatment decisions for people diagnosed with this disease?

Our biggest efforts should focus on preventing lung cancer or any cancer if possible. But unfortunately, in 2025, over 200,000 people in the U.S. will be diagnosed with lung cancer. So, diagnosis and treatment planning are critical.

Testing plays a role at different stages of the disease. Lung cancer can present at stage 1 or 2 (the earliest stages) or stage 4, which is the most advanced. Stage 1 and 2 are typically curable with surgery, sometimes combined with other modalities. Stage 4 cancer isn’t curable, but we aim to put it in remission. Stage 3 is somewhere in between.

Testing is important throughout, but it’s most critical in later stages. Traditional treatments include surgery, radiation, and chemotherapy. In later years, we also use immunotherapy and targeted therapy. Genomic testing helps identify targets for these therapies. Essentially, mutations in cancer cells act like switches that turn normal cells into cancer cells. If we identify a switch, we may find a drug that targets it.

For lung cancer, targeted therapies have evolved since the early 2000s. Tyrosine kinase inhibitors, for example, can act quickly, reduce side effects, and improve overall survival. Some patients report improvement within weeks of starting treatment.

What challenges arise when patients are diagnosed at a more advanced stage, such as metastasis? How are these patients managed?

The more advanced the cancer, the bigger the challenge. There are more cancer cells to target, and other organs may be affected. Organ function matters because medications are metabolized in the body, often by the liver or kidneys. If those organs aren’t functioning normally, treatment options may be limited.

Patients may feel unwell due to comorbidities, like diabetes or kidney issues, or from the burden of the disease itself. For those who feel relatively well, aggressive treatment and supportive care can reduce the cancer burden and improve quality of life.

In oncology, we identify more and more actionable targets for personalized treatment. For example, EGFR mutations, which are particularly common in certain populations, guide targeted therapies. Today, up to 50% of lung cancer patients may have one of 10 known actionable mutations. This has revolutionized care, especially for advanced-stage patients.

How can increased awareness and early screening improve outcomes for those at risk of lung cancer, regardless of smoking history?

The earlier we identify lung cancer, the better the chances of curing it and living a normal lifespan. Lung cancer screening recommendations exist for smokers, but other factors, like family history or genetic predisposition, also matter.

Some genetic mutations, like EGFR, may indicate higher risk and can be detected through germline testing, which looks at every cell in the body. Early identification helps guide prevention and treatment strategies.

What key messages should patients know about cancer risk, early detection, and living with a diagnosis?

Patients should know that everyone is at risk. According to the American Cancer Society, one in four people will be diagnosed with cancer in their lifetime. If symptoms persist for months, don’t ignore them — get evaluated.

Once diagnosed with lung cancer, it’s not a death sentence. With current strategies, including targeted therapies and immunotherapy, people can live long, meaningful lives. Patients can plan events, have families, and maintain quality of life.

Incidence of some cancers is rising in younger populations, particularly colon cancer. Awareness and early detection are critical across all cancer types, not just lung cancer.

Transcript has been edited for clarity and conciseness.

For more news on cancer updates, research and education, don’t forget to subscribe to CURE®’s newsletters here.