Lung Cancer Can Affect Nonsmokers, Too

When someone is diagnosed with lung cancer, one of the first questions they may hear is, “Did you smoke?”

Smoking is the leading cause of lung cancer, but it is not the only cause. Each year, an estimated 20,000 to 40,000 lung cancer cases in the U.S. occur in those who have never smoked (or individuals who have smoked fewer than 100 cigarettes in their lifetime). Understanding the other risks can help reduce stigma and prevent symptoms from being dismissed simply because someone has never used tobacco.

Secondhand Smoke Can Increase Risk

A person does not have to smoke a cigarette to be exposed to harmful tobacco smoke.

Secondhand smoke includes smoke released from a burning cigarette, cigar or pipe, as well as smoke exhaled by someone using tobacco. Exposure may happen at home, in a vehicle, at work or in other shared spaces.

Opening a window, using a fan or smoking in another room does not eliminate the exposure. Maintaining smoke-free homes and vehicles is the most effective way to protect others.

Radon May Be Present in the Home

Radon is a naturally occurring radioactive gas that can enter buildings through cracks and openings in the foundation. It cannot be seen, smelled or tasted, so testing is the only way to know whether it is present.

Long-term radon exposure can damage cells in the lungs. It is one of the leading causes of lung cancer among people who do not smoke.

Home radon testing kits are widely available. When high levels are detected, a qualified professional can install a mitigation system to reduce the amount of radon inside the home.

Some Workplace Exposures Matter

People who work or previously worked in factories, mines, construction sites and other industrial settings may have been exposed to cancer-causing substances.

Potential workplace hazards include:

• Asbestos
• Arsenic
• Diesel exhaust
• Silica dust
• Chromium
• Nickel
• Certain radioactive materials

Risk can depend on the substance, length of exposure and protective equipment used. Smoking may further increase the risk associated with some occupational exposures.

Lung cancer may develop decades after the original exposure. People should tell their healthcare provider about previous jobs and workplace conditions, even if that work took place many years ago.

Other Factors May Play a Role

Long-term exposure to air pollution may contribute to lung cancer risk. Family history, certain genetic changes and previous radiation therapy to the chest also may be factors.

Sometimes, a person develops lung cancer without any known risk factor. Researchers are continuing to study why lung cancer occurs in people who have never smoked.

Cancer in the Lungs Is Not Always Lung Cancer

Primary lung cancer begins in the lungs. Metastatic cancer begins somewhere else in the body and then spreads to the lungs.

For example, breast cancer that spreads to the lungs is still considered metastatic breast cancer. It is generally treated based on where the cancer originally developed.

This is different from lung cancer that begins in the lungs and later spreads to another part of the body.

Do Not Ignore Persistent Symptoms

Possible signs of lung cancer may include:

• A cough that does not go away or continues to worsen
• Chest pain
• Coughing up blood
• Loss of appetite
• Shortness of breath
• Wheezing or hoarseness
• Repeated pneumonia or bronchitis
• Unexplained weight loss
• Persistent fatigue

These symptoms can have many causes and do not necessarily mean someone has cancer. However, symptoms that persist, worsen or have no clear explanation should be evaluated.

People who have never smoked should not assume lung cancer is impossible. Sharing information about secondhand smoke, radon, workplace exposure, previous cancer treatment and family history can help a healthcare provider determine whether further testing is needed.

No one deserves lung cancer, regardless of smoking history. Persistent symptoms deserve attention—not judgment.