Nonsmokers Still at Risk for Lung Cancer

If you don’t smoke, you’ve eliminated one of the most significant risk factors for lung cancer. However, approximately 10% to 20% of lung cancer diagnoses in the U.S. occur in individuals who have never smoked or have smoked fewer than 100 cigarettes in their lifetime. And while the odds of avoiding lung cancer are generally in your favor, nonsmokers can and do get it. 

In 2018, as many as 20% of lung cancer-related deaths—about 30,000 people—occurred among nonsmokers. Like all cancers, lung cancer starts at the cellular level with abnormal cells that multiply rapidly and uncontrollably, potentially spreading to other organs or bones according to the Centers for Disease Control. 

Types of Lung Cancer and Risk Factors for Nonsmokers

Lung cancer is generally classified as either non-small cell lung cancer (NSCLC) or small cell lung cancer (SCLC), with NSCLC being the most common among nonsmokers, particularly a subtype known as adenocarcinoma. This form of cancer often begins in the mucus-producing cells of the lungs’ outer areas, called bronchioles. According to Dr. Alexander Tungesvik, an oncologist at Missouri Cancer Associates, while there may not be a single cause behind lung cancer in nonsmokers, it is often influenced by several factors, both genetic and environmental.

Genetic Mutations
One of the strongest predictors of lung cancer in nonsmokers is genetic changes, particularly somatic mutations, which develop within tumors and drive cancer growth. This differs from germline mutations, which are present in all normal DNA. Studies have shown that somatic mutations are common contributors to lung cancer in nonsmokers.

Environmental Factors
Environmental exposures can significantly elevate the risk of lung cancer in nonsmokers. Key contributors include:

  • Radon gas: A colorless, odorless gas linked to around 21,000 lung cancer deaths each year. It can accumulate in homes built on uranium-rich soil.
  • Secondhand smoke: Inhaling smoke from others’ cigarettes, which accounts for approximately 7,000 lung cancer deaths annually.
  • Carcinogens at work: Exposure to harmful substances such as asbestos, diesel exhaust, and heavy metals.
  • Air pollution: Indoor and outdoor pollutants, though regulated in the U.S., can still pose a risk for lung cancer over long-term exposure.

Recognizing Symptoms and Screening for Lung Cancer in Nonsmokers

Nonsmokers may benefit from lung cancer screening if they have a family history of the disease or other risk factors. Since early-stage lung cancer often presents no symptoms, being vigilant about the following signs can support early detection:

  • Persistent cough
  • Coughing up blood
  • Chest pain or discomfort
  • Shortness of breath or wheezing
  • Unexplained weight loss
  • Fatigue
  • Recurrent lung infections

    Diagnosing and Treating Lung Cancer in Nonsmokers

    If your doctor recommends screening, diagnostic options may include imaging tests like CT scans and MRIs, and may involve a biopsy for genetic testing. At Missouri Cancer Associates, genetic profiling is often part of the treatment paradigm as it allows oncologists to tailor treatment with targeted therapies, which are specialized drugs designed to kill cancer cells selectively.

    Surgery remains the preferred treatment for early-stage lung cancer. Dr.Tungesvik emphasizes the importance of early detection, as it improves surgical outcomes by containing cancer to a specific area of the lungs. Genetic testing and personalized treatment plans, including immunotherapy, chemotherapy, and advanced drug therapies, have greatly improved survival rates and quality of life for patients.

    Reducing Your Risk

    While you can’t change certain risk factors, like family history, you can take steps to protect yourself:

    • Test your home for radon.
    • Avoid secondhand smoke and limit exposure to carcinogens.
    • Maintain a balanced diet rich in fruits and vegetables.
    • Discuss personal risk factors with your doctor if lung cancer runs in your family.

    Lung Cancer Diagnosis and Treatment Options

    If your physician recommends testing for lung cancer, the diagnostic process will begin with a physical exam and a review of your medical history. Common diagnostic tools include imaging tests such as chest X-rays, CT scans, MRIs, PET scans, bone scans, and ultrasounds. Physicians may also collect cell samples from saliva, lung fluid, or a biopsy to check for cancerous cells or genetic abnormalities.

    For nonsmokers, adenocarcinoma is the most commonly diagnosed type of lung cancer. It typically starts in the mucus-producing cells in the outer areas of the lungs. Although lung cancer in nonsmokers tends to grow more slowly and may be less likely to spread, early detection is crucial for successful treatment.

    Treatment options for lung cancer can vary based on individual circumstances and may include:

    Your treatment plan will be tailored to your specific diagnosis, and outcomes are often better when lung cancer is caught early.

    If you or a loved one has recently been diagnosed with lung cancer, contact Missouri Cancer Associates at (573) 874-7800 or make an appointment here.