Lung Can­cer

Lung cancer is the leading cause of cancer death. Not counting some kinds of skin cancer, lung cancer is 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 cancers usually are grouped into two main types called small cell and non-small cell (including adenocarcinoma and squamous cell carcinoma). These types of lung cancer grow differently and are treated differently. Non-small cell lung cancer is more common than small cell lung cancer. For more information, visit the National Cancer Institute’s Lung Cancer.

A medical illustration of the respiratory system, showing the lungs, bronchi, trachea, larynx, pharynx, and nasal cavity

This illustration of the respiratory system shows the lungs, bronchi, trachea, larynx, pharynx, and nasal cavity.

Basic Information

Research has found several risk factors that may increase your chances of getting lung cancer.


Cigarette smoking is the number one risk factor for lung cancer. In the United States, cigarette smoking is linked to about 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 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.

Secondhand Smoke

Smoke from other people’s cigarettes, pipes, or cigars (secondhand smoke) also causes lung cancer. When a person breathes in secondhand smoke, it is like he or she is smoking. In the United States, one out of four people who don’t smoke, including 14 million children, were exposed to secondhand smoke during 2013 to 2014.


This video explains what radon is, how it can enter your home and cause lung cancer, and how to fix a radon problem if needed.

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.

The U.S. Environmental Protection Agency (EPA) estimates that radon causes about 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, the EPA estimates that more than 10% of radon-related lung cancer deaths occur among people who have never smoked cigarettes. Nearly one out of every 15 homes in the United States has high radon levels. Learn how to test your home for radon and reduce the radon level if it is high.

Other Substances

Examples of substances found at some workplaces that increase risk include asbestos,arsenic,diesel exhaust, and some forms of silica and chromium. For many of these substances, the risk of getting lung cancer is even higher for those who smoke.

Personal or Family History of Lung Cancer

If you are a lung cancer survivor, there is a risk that you may develop another lung cancer, especially if you smoke. Your risk of lung cancer may be higher if your parents, brothers or sisters, or children have had lung cancer. This could be true because they also smoke, or they live or work in the same place where they are exposed to radon and other substances that can cause lung cancer.

Radiation Therapy to the Chest

Cancer survivors who had radiation therapy to the chest are at higher risk of lung cancer.


Scientists are studying many different foods and dietary supplements to see whether they change the risk of getting lung cancer. There is much we still need to know. We do know that people who smoke and take beta-carotene supplements have increased risk of lung cancer. For more information, visit Lung Cancer Prevention.

Also, arsenic and radon in drinking water (primarily from private wells) can increase the risk of lung cancer.

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.
  • Wheezing.
  • 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.

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. Smoke from other people’s cigarettes, cigars, or pipes is called secondhand smoke. Make your home and car smoke-free.
  • Get your home tested for radon. The U.S. 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.

“We did it. You can, too!” Three former smokers share tips that helped them quit in this video. For more help quitting, visit

Screening means testing for a disease when there are no symptoms or history of that disease. Doctors recommend a screening test to find a disease early, when treatment may work better.

The only recommended screening test for lung cancer is low-dose computed tomography (also called a low-dose CT scan, or LDCT). During an LDCT scan, you lie on a table and an X-ray machine uses a low dose (amount) of radiation to make detailed images of your lungs. The scan only takes a few minutes and is not painful.

Who Should Be Screened?

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.

Risks of Screening

Lung cancer screening has at least three risks—

  • A lung cancer screening test can suggest that a person has lung cancer when no cancer is present. This is called a false-positive result. False-positive results can lead to follow-up tests and surgeries that are not needed and may have more risks.
  • A lung cancer screening test can find cases of cancer that may never have caused a problem for the patient. This is called overdiagnosis. Overdiagnosis can lead to treatment that is not needed.
  • Radiation from repeated LDCT tests can cause cancer in otherwise healthy people.

That is why lung cancer screening is recommended only for adults who are at high risk for developing the disease because of their smoking history and age, and who do not have a health problem that substantially limits their life expectancy or their ability or willingness to have lung surgery, if needed.

If you are thinking about getting screened, talk to your doctor. If lung cancer screening is right for you, your doctor can refer you to a high-quality screening facility.

The best way to reduce your risk of lung cancer is to not smoke and to avoid secondhand smoke. Lung cancer screening is not a substitute for quitting smoking.

When Should Screening Stop?

The Task Force recommends that yearly lung cancer screening stop when the person being screened—

  • Turns 81 years old, or
  • Has not smoked in 15 or more years, or
  • Develops a health problem that makes him or her unwilling or unable to have surgery if lung cancer is found.

Insurance and Medicare Coverage

Most insurance plans and Medicare help pay for recommended lung cancer screening tests. Check with your insurance plan to find out what benefits are covered for lung cancer screening. For more information about Medicare coverage, visit or call 1-800-MEDICARE (1-800-633-4227). TTY users should call 1 (877) 486-2048.

More Information

Types of Lung Cancer

The two main types of lung cancer are small cell lung cancer and non-small cell lung cancer. These categories refer to what the cancer cells look like under a microscope. Non-small cell lung cancer is more common than small cell lung cancer.

If you have lung cancer (especially non-small cell lung cancer), your doctor may run tests to find out if you have a change in your genes (genetic mutation). The results of these tests help your doctor know which treatments will work best for you.


If lung cancer is diagnosed, other tests are done to find out how far it has spread through the lungs, lymph nodes, and the rest of the body. This process is called staging. The type and stage of lung cancer tells doctors what kind of treatment you need. For more information, visit Stages of Non-Small Cell Lung Cancer and Stages of Small Cell Lung Cancer.

Types of Treatment

Lung cancer is treated in several ways, depending on the type of lung cancer and how far it has spread. People with non-small cell lung cancer can be treated with surgery, chemotherapy, radiation therapy, targeted therapy, or a combination of these treatments. People with small cell lung cancer are usually treated with radiation therapy and chemotherapy.

  • Surgery. An operation where doctors cut out cancer tissue.
  • Chemotherapy. Using special medicines to shrink or kill the cancer. The drugs can be pills you take or medicines given in your veins, or sometimes both.
  • Radiation therapy. Using high-energy rays (similar to X-rays) to kill the cancer.
  • Targeted therapy. Using drugs to block the growth and spread of cancer cells. The drugs can be pills you take or medicines given in your veins. You will get tests to see if targeted therapy is right for your cancer type before this treatment is used.

Doctors from different specialties often work together to treat lung cancer. Pulmonologists are doctors who are experts in diseases of the lungs. Surgeons are doctors who perform operations. Thoracic surgeons specialize in chest, heart, and lung surgery. Medical oncologists are doctors who treat cancer with medicines. Radiation oncologists are doctors who treat cancers with radiation.

For more information, visit the National Cancer Institute’s Lung Cancer page. This site can also help you find a doctor or treatment facility that works in cancer care.

Clinical Trials

Clinical trials use new treatment options to see if they are safe and effective. For more information, visit the National Cancer Institute’s Clinical Trials page. If you have cancer, you may want to take part. Visit the sites listed below to find a clinical trial.

Complementary and Alternative Medicine

Complementary and alternative medicine are medicines and health practices that are not standard treatments doctors usually use to treat cancer.

  • Complementary medicine is used in addition to standard treatments. Examples include acupuncture, dietary supplements, massage therapy, hypnosis, and meditation.
  • Alternative medicine is used instead of standard treatments. Examples include special diets, megadose vitamins, herbal preparations, special teas, and magnet therapy.

Many kinds of complementary and alternative medicine have not been tested scientifically and may not be safe. Talk to your doctor about the risks and benefits before you start any kind of complementary or alternative medicine.

Which Treatment Is Right for Me?

Choosing the treatment that is right for you may be hard. Talk to your cancer doctor about the treatment options available for your type and stage of cancer. Your doctor can explain the risks and benefits of each treatment and their side effects.Side effects are how your body reacts to drugs or other treatments.

Sometimes people get an opinion from more than one cancer doctor. This is called a “second opinion.” Getting a second opinion may help you choose the treatment that is right for you.

Life with Lung Cancer

When you have been diagnosed with cancer, you are considered a cancer survivor from that moment throughout the rest of your life.

Finding lung cancer earlier and making new treatments available are helping more lung cancer survivors live longer. The big challenge ahead is, “How do I live with lung cancer, as long and as best I can?” We offer some tips below.

It’s important to get the treatment you need when you need it. You deserve timely and appropriate care for your lung cancer and its symptoms (including pain), as well as any side effects of treatment. Molecular testing (also called tumor or biomarker testing) may help you make decisions about treatment.

Talk with your health care provider about how a survivorship care plan can help you coordinate your follow-up care to support your physical and emotional health.

Take steps to stay healthy. This can lower your risk of getting cancer again or having the cancer come back.

Some cancer survivors may blame themselves or feel that others blame them for having cancer. Lung cancer survivors may have these feelings of blame or stigma. You may find it helpful to talk about your experiences and feelings with a social worker or mental health professional. You may also find it helpful to share your story with other cancer survivors or listen to their stories.

Lung cancer can be caused by many risk factors other than smoking cigarettes, pipes, or cigars. These risk factors include exposure to other people’s smoke (called secondhand smoke), radon, air pollution, a family history of lung cancer, and asbestos.

In the United States, about 10% to 20% of lung cancers, or 20,000 to 40,000 lung cancers each year, happen in people who never smoked or smoked fewer than 100 cigarettes in their lifetime. Researchers estimate that secondhand smoke contributes to about 7,300 and radon to about 2,900 of these lung cancers.

What Are the Symptoms of Lung Cancer Among People Who Never Smoked?

Symptoms of lung cancer are the same, whether or not you have smoked. Some people have general symptoms of not feeling well or feeling tired all the time. Some people cough frequently, cough up blood, or have chest pain, wheezing, or shortness of breath.

These symptoms can happen with other illnesses. If you have any of these symptoms, talk to your doctor, who can help find the cause.

How Can I Help Lower My Risk of Getting Lung Cancer?

You can help lower your risk of lung cancer by staying away from secondhand smoke, diesel exhaust, and other air pollution. You should get your home tested for radon and take steps to lower the radon level if it is high.

Some risk factors, such as a personal or family history of lung cancer, can’t be changed. If lung cancer runs in your family, talk to your doctor about actions you can take stay healthy. People with lung cancer who have never smoked may have a DNA mutation, such as a mutation in the epidermal growth factor receptor (EGFR) gene or other genes. Cancers caused by these mutations may be treated with targeted therapy.

Is Lung Cancer Screening Recommended for People Who Never Smoked?

The U.S. Preventive Services Task Force does not recommend lung cancer screening for people who have never smoked. That’s because the possible harms of screening outweigh the possible benefit (finding lung cancer early) in this group.

What Types of Lung Cancer Are Diagnosed in People Who Never Smoked?

About 50% to 60% of lung cancers found in people who never smoked are adenocarcinomas (cancer that begins in the cells that line the lung’s tiny air sacs and make substances such as mucus). About 10% to 20% are squamous cell carcinomas (cancer that forms in the thin, flat cells lining the inside of the lungs). A few (6% to 8%) are small cell lung cancers, and the rest are other types of lung cancer.

Content sourced from the Centers for Disease Control and Prevention, June 2022.

For your convenience, Onslow Radiation Oncology has compiled a Cancer Resources page for even more information.