Lung cancer is the leading cause of cancer death, and the second-most diagnosed cancer, in both men and women in the United States. After increasing for decades, lung cancer rates are decreasing nationally, as fewer people smoke cigarettes and as lung cancer treatments improve.
Cigarette smoking is the number one cause of lung cancer. Lung cancer also can be caused by using other types of tobacco (such as pipes or cigars), breathing secondhand smoke, being exposed to substances such as asbestos or radon at home or work, and having a family history of lung cancer.
Lung Cancer Risk Factors
Cigarette smoking is the No. 1 risk factor for lung cancer. In the United States, cigarette smoking is linked to 80% to 90% of lung cancer deaths. Using other tobacco products such as cigars or pipes also increases the risk for lung cancer. Tobacco smoke is a toxic mix of more than 7,000 chemicals. Many are poisons. At least 70 are known to cause cancer in people or animals.
People who smoke cigarettes are 15 to 30 times more likely to get lung cancer, or die from lung cancer, than people who do not smoke. Even smoking a few cigarettes a day, or smoking occasionally, increases the risk of lung cancer. The more years a person smokes and the more cigarettes smoked each day, the more the risk goes up.
People who quit smoking have a lower risk of lung cancer than if they had continued to smoke, but their risk is higher than the risk for people who never smoked. Quitting smoking at any age can lower the risk of lung cancer.
Cigarette smoking can cause cancer almost anywhere in the body. Cigarette smoking causes cancer of the mouth and throat, esophagus, stomach, colon, rectum, liver, pancreas, voicebox (larynx), trachea, bronchus, kidney and renal pelvis, urinary bladder, and cervix, and causes acute myeloid leukemia.
Smoke from other people’s cigarettes, pipes, or cigars also causes lung cancer. When a person breathes in secondhand smoke, it is like he or she is smoking.
After smoking, radon is the second-leading cause of lung cancer in the United States. Radon is a naturally occurring gas that forms in rocks, soil and water. It cannot be seen, tasted or smelled. When radon gets into homes or buildings through cracks or holes, it can get trapped and build up in the air inside. People who live or work in these homes and buildings breathe in high radon levels. Over long periods of time, radon can cause lung cancer.
Radon causes an estimated 21,000 lung cancer deaths each year. The risk of lung cancer from radon exposure is higher for people who smoke than for people who don’t smoke. However, it is estimated that more than 10% of radon-related lung cancer deaths occur among people who have never smoked cigarettes.
Lung Cancer Symptoms
Different people have different symptoms for lung cancer. Some people have symptoms related to the lungs. Some people whose lung cancer has spread to other parts of the body (metastasized) have symptoms specific to that part of the body. Some people just have general symptoms of not feeling well. Most people with lung cancer don’t have symptoms until the cancer is advanced. Lung cancer symptoms may include—
- Coughing that gets worse or doesn’t go away.
- Chest pain.
- Shortness of breath.
- Coughing up blood.
- Feeling very tired all the time.
- Weight loss with no known cause.
Other changes that can sometimes occur with lung cancer may include repeated bouts of pneumonia and swollen or enlarged lymph nodes (glands) inside the chest in the area between the lungs.
These symptoms can happen with other illnesses, too. If you have some of these symptoms, talk to your doctor, who can help find the cause.
Lung Cancer Prevention
You can help lower your risk of lung cancer in the following ways—
- Don’t smoke. Cigarette smoking causes about 80% to 90% of lung cancer deaths in the United States. The most important thing you can do to prevent lung cancer is to not start smoking, or to quit if you smoke.
- Avoid secondhand smoke. Make your home and car smoke-free.
- Get your home tested for radon. The Environmental Protection Agency recommends that all homes be tested for radon.
- Be careful at work. Health and safety guidelines in the workplace can help workers avoid carcinogens—things that can cause cancer.
The only recommended screening test for lung cancer is low-dose computed tomography (also called a low-dose CT scan or LDCT). The U.S. Preventive Services Task Force (USPSTF) recommends yearly lung cancer screening with LDCT for people who—
- Have a 20 pack-year or more smoking history, and
- Smoke now or have quit within the past 15 years, and
- Are between 50 and 80 years old.
A pack-year is smoking an average of one pack of cigarettes per day for one year. For example, a person could have a 20 pack-year history by smoking one pack a day for 20 years or two packs a day for 10 years.
Lung Cancer Treatment
Lung cancer treatment depends on the stage and overall medical condition of the patient. In patients with early-stage lung cancer who are not able to undergo surgical resection, Community Cancer Center physicians employ a stereotactic ablative technique that involves the delivery of highly conformal, high dose radiation over one to five treatments. For more advanced lung cancers that are inoperable, radiation treatment is delivered (typically with chemotherapy) in smaller daily doses over a period of six weeks.