Lung Cancer in Non-Smokers: Why Cases Are Rising and What You Need to Know

Lung cancer is no longer a disease that affects only older smokers. Cases are increasingly being diagnosed among women, younger adults and people who have never smoked. Understanding the possible causes, recognizing early symptoms and improving access to screening could help more people receive timely diagnoses and treatment.

Recent attention surrounding Pope Leo XIV's reported lung cancer diagnosis in October 2026 has also highlighted an important issue: people who have never smoked can still develop lung cancer.

So, why are lung cancer rates changing, what factors increase the risk, and what should people know about prevention and early detection?

Why Is Lung Cancer Increasing Among Non-Smokers?

Smoking remains the leading risk factor for lung cancer. However, it is not the only cause. Lung cancer can develop in people with no history of smoking, and researchers are investigating the environmental, genetic and biological factors that may explain these cases.

According to Estelamari Rodriguez, an associate director of community outreach in thoracic oncology at the University of Miami, the profile of people diagnosed with lung cancer has changed significantly over recent decades.

More women, younger adults and never-smokers are being diagnosed. This challenges the common misconception that lung cancer is exclusively associated with older people who smoke heavily.

The distinction matters because people who do not smoke may not recognize their symptoms as potential signs of lung cancer. They may also assume they are unlikely to develop the disease, potentially delaying medical assessment.

Why Are More Women Being Diagnosed With Lung Cancer?

Several factors may help explain changing lung cancer patterns among women.

Historically, women began smoking later than men in many populations. As a result, increases in smoking-related lung cancer diagnoses among women may have occurred later.

The widespread use of filtered cigarettes has also been investigated as a contributing factor. Some research suggests that changes in cigarette design and the distribution of smoke within the lungs may have influenced the incidence of adenocarcinoma, a common type of lung cancer.

Researchers have also explored whether women may be more susceptible to certain carcinogens in tobacco smoke, including secondhand smoke. Some evidence suggests that lung cancer can develop after relatively limited smoking exposure in some individuals.

However, smoking patterns alone do not explain every diagnosis.

Rodriguez reports that approximately 20 per cent of women diagnosed with lung cancer have never smoked, a higher proportion than among men diagnosed with the disease.

These findings highlight the importance of considering other risk factors rather than relying solely on smoking history.

Lung Cancer Risk Factors Beyond Smoking

Although smoking and exposure to secondhand smoke remain important risk factors, several other factors can contribute to lung cancer.

1. Air pollution

Long-term exposure to polluted air is associated with an increased risk of lung cancer. Harmful particles and substances in the air can enter the lungs and contribute to damage over time.

2. Radon exposure

Radon is a naturally occurring radioactive gas that can accumulate inside buildings. Prolonged exposure to high levels increases lung cancer risk, including among people who have never smoked.

3. Workplace chemicals

Certain occupations can expose workers to substances associated with lung cancer. These include asbestos, arsenic, beryllium, cadmium, silica and nickel. The level of risk depends on the substance, the duration of exposure and the protective measures available.

4. Secondhand smoke

Breathing in other people's tobacco smoke can expose non-smokers to carcinogenic chemicals. Avoiding tobacco smoke remains an important way to reduce preventable risk.

5. Family history and genetics

People with a family history of lung cancer may have an increased risk, although family history does not mean that someone will inevitably develop the disease.

Researchers are investigating genetic variations that could make some individuals more susceptible to lung cancer. Understanding these inherited factors may eventually help doctors identify people who could benefit from more personalized monitoring.

6. E-cigarettes and marijuana smoke

The long-term effects of vaping and marijuana smoke on lung cancer risk remain under investigation. The evidence is still developing, so their precise contribution to lung cancer incidence is not yet fully understood.

Can Genetics Increase Lung Cancer Risk?

Genetics is an increasingly important area of lung cancer research.

Certain changes in DNA can affect how cells grow, repair damage and respond to signals that regulate their development. When these processes become disrupted, cells may grow uncontrollably and form tumours.

Researchers have identified genetic changes within lung cancer tumours that can help guide treatment. However, the inherited genetic factors that predispose otherwise healthy people to lung cancer are less fully understood.

Families with several members affected by lung cancer are particularly important in research. Studying these families may help scientists identify susceptibility genes and develop biomarkers that could eventually support earlier detection.

It is important to distinguish between inherited risk and genetic changes that develop within a tumour. They are not the same, and not everyone with a family history needs genetic testing. People concerned about their family history can discuss their circumstances with a healthcare professional.

Early Symptoms of Lung Cancer You Should Not Ignore

One of the biggest challenges in diagnosing lung cancer is that its early symptoms can be subtle or resemble other conditions.

Possible symptoms include:

• A persistent cough or a cough that changes over time.
• Shortness of breath.
• Unusual or persistent fatigue.
• Pain in the chest, back or shoulder.
• Recurrent chest infections.
• Coughing up blood.
• Unexplained weight loss.

These symptoms do not necessarily indicate lung cancer. Many have other causes, but persistent, unexplained or worsening symptoms should be assessed by a healthcare professional.

People who have never smoked should not dismiss concerning symptoms simply because they do not fit the traditional image of a lung cancer patient.

Women and younger adults may sometimes attribute symptoms to less serious conditions, while clinicians may initially consider other explanations because of their age or smoking history. Greater awareness among patients and healthcare professionals could help reduce diagnostic delays.

If you cough up blood, seek urgent medical advice. Severe breathing difficulties or significant chest pain may require emergency care.

Who Should Consider Lung Cancer Screening?

Screening aims to identify lung cancer before symptoms develop, when treatment may be more effective.

Low-dose computed tomography, commonly called a low-dose CT scan, can detect small abnormalities in the lungs. However, screening is not recommended for everyone because it can also identify abnormalities that are not cancer and lead to further testing.

In the United States, the US Preventive Services Task Force recommends annual low-dose CT screening for eligible adults aged 50 to 80 who have a smoking history of at least 20 pack-years and currently smoke or quit within the previous 15 years.

A pack-year is equivalent to smoking an average of one pack of cigarettes daily for one year.

These criteria are specific to US guidance. Eligibility and screening arrangements differ between countries. In the UK, people should consult NHS guidance and their healthcare team about available lung cancer screening programmes and their individual circumstances.

Importantly, never-smokers are not routinely eligible for screening under standard smoking-based criteria. Researchers are investigating ways to identify higher-risk individuals using factors such as family history, environmental exposure and genetic biomarkers.

Screening is different from diagnostic testing. Someone with concerning symptoms should seek medical assessment rather than waiting to qualify for a screening programme.

Advances in Lung Cancer Treatment Offer Hope

Although lung cancer remains a major cause of cancer-related deaths, treatment has advanced considerably.

Targeted therapies are designed to act on specific molecular changes in cancer cells. Immunotherapies help the immune system recognize and attack cancer. Depending on the cancer type and stage, treatment may also include surgery, radiotherapy or chemotherapy.

When lung cancer is detected at an early stage, surgery may offer the possibility of a cure for suitable patients, including those who have never smoked.

Some patients with particular tumour characteristics may benefit substantially from targeted treatments. Molecular testing can therefore play an important role in selecting the most appropriate therapy.

Earlier diagnosis, wider awareness of symptoms and continued research into genetic and environmental risk factors are all important steps towards improving outcomes.

Final Thoughts

The changing face of lung cancer shows why smoking history alone cannot determine who is at risk.

Although smoking prevention remains essential, factors such as air pollution, radon, occupational exposures, secondhand smoke and genetics also deserve attention. Recognizing symptoms and seeking medical advice promptly can help reduce delays in diagnosis.

People should not assume they are immune to lung cancer because they have never smoked. At the same time, having a risk factor does not mean that cancer will inevitably develop.

Greater awareness, evidence-based screening and advances in personalized treatment could help more people receive an accurate diagnosis and appropriate care.

Disclaimer: This article is for general informational and educational purposes only. It does not replace professional medical advice, diagnosis or treatment. If you have persistent or concerning symptoms, consult a qualified healthcare professional. Do not delay seeking medical advice because of information presented here.