Lung Cancer: Early Warning Signs and Risks for Non-Smokers
- Lung cancer is frequently associated with smoking, but a significant number of cases occur in individuals who have never used tobacco.
- Other sources indicate that between 10% and 20% of lung cancer cases happen in people who have never smoked.
- While smoking is the most common cause, several environmental and genetic factors contribute to the development of lung cancer in nonsmokers.
Lung cancer is frequently associated with smoking, but a significant number of cases occur in individuals who have never used tobacco. According to the American Cancer Society, as many as 20 percent of people in the United States who died from lung cancer in 2018—approximately 30,000 people—were nonsmokers.
Other sources indicate that between 10% and 20% of lung cancer cases happen in people who have never smoked. This underscores the importance of recognizing symptoms and risk factors that extend beyond cigarette use to ensure earlier diagnosis and better treatment outcomes.
Risk Factors for Nonsmokers
While smoking is the most common cause, several environmental and genetic factors contribute to the development of lung cancer in nonsmokers. Exposure to secondhand smoke can increase the risk by 20-30%.
Other significant environmental dangers include exposure to radon, and asbestos. A family history of lung cancer and certain lung scarring conditions can substantially increase a person’s risk.
Medical research indicates that nonsmokers tend to develop different types of lung cancer than smokers. This group is more likely to develop the disease as a result of a genetic mutation or abnormality. Specifically, adenocarcinoma is identified as the main type of lung cancer that nonsmokers develop.
Identifying Symptoms
Many lung cancers do not cause symptoms until the disease has spread, which can make early detection challenging. However, some individuals with early-stage lung cancer do experience warning signs.
The most common symptoms of lung cancer include:
- A cough that persists or worsens over time
- Coughing up blood or rust-colored sputum (phlegm or spit)
- Chest pain, which often intensifies during laughing, coughing, or deep breathing
- Shortness of breath and new onset of wheezing
- Hoarseness
- Unexplained weight loss and loss of appetite
- Feeling weak or tired
- Recurrent infections, such as pneumonia or bronchitis, that do not resolve
In some cases, tumors in the upper part of the lungs, known as Pancoast tumors, can affect nerves to the face and eye. This can lead to Horner syndrome, characterized by a smaller pupil on one side of the face, drooping or weakness of one upper eyelid, and little to no sweating on that same side of the face. Pancoast tumors may also cause severe shoulder pain.
Signs of Advanced Disease
When lung cancer spreads to other parts of the body, it may produce a different set of symptoms depending on the location of the metastasis.
- Spread to the brain: May cause seizures, dizziness, balance problems, headaches, or numbness and weakness in a leg or arm.
- Spread to the liver: May result in jaundice, characterized by yellowing of the eyes and skin.
- Spread to the bones: Often manifests as pain in the hips or back.
- Lymphatic spread: May cause swelling of the lymph nodes, particularly those above the collarbone or in the neck.
Treatment and Diagnosis Trends
The approach to treating lung cancer in nonsmokers has evolved as medical understanding of the disease has grown. Because the types of lung cancer found in nonsmokers are often driven by detectable molecular changes or mutations in the tumor, targeted drugs and therapeutics are available.
Current research programs, such as those at Yale Medicine, are focused on targeting the specific cancer cells that contain these mutations to improve patient outcomes.