Cancer Guide

What is Lung Cancer?

When treating lung cancer with radiation, the challenge is to precisely target the tumor while minimizing the radiation exposure to the surrounding healthy tissue and organs. At Ocean Radiation Oncology, we use the cutting-edge technology of the TomoTherapy Hi-ART treatment delivery system to effectively meet this challenge. In addition, our well-established Stereotactic Radiation Therapy program helps us treat small lung tumors using highly focused, precise radiation treatments.


Lung cancers include those cancers that start in the lung (non-small cell lung cancer and small cell lung cancer), as well as those cancers that have started in other parts of the body and then spread to the lungs (lung metastases). Non-small cell lung cancer, small cell lung cancer, and lung metastases will often require radiation treatments. Patients with lung tumors will sometimes undergo surgery and/or chemotherapy as well.

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Doctors cannot always explain why one person develops lung cancer and another does not. However, we do know that a person with certain risk factors may be more likely than others to develop lung cancer. A risk factor is something that may increase the chance of developing a disease.

Studies have found the following risk factors for lung cancer:

  • Tobacco smoke: Tobacco smoke causes most cases of lung cancer. It's by far the most important risk factor for lung cancer. Harmful substances in smoke damage lung cells. That's why smoking cigarettes, pipes, or cigars can cause lung cancer, and why secondhand smoke can cause lung cancer in nonsmokers. The more a person is exposed to smoke, the greater the risk of lung cancer. For more information, see the NCI fact sheets Harms of Smoking and Health Benefits of Quitting and Secondhand Smoke and Cancer.
  • Radon: Radon is a radioactive gas that you cannot see, smell, or taste. It forms in soil and rocks. People who work in mines may be exposed to radon. In some parts of the country, radon is found in houses. Radon damages lung cells, and people exposed to radon are at increased risk of lung cancer. The risk of lung cancer from radon is even higher for smokers. For more information, see the NCI fact sheet Radon and Cancer.
  • Asbestos and other substances: People who have certain jobs (such as those who work in the construction and chemical industries) have an increased risk of lung cancer. Exposure to asbestos, arsenic, chromium, nickel, soot, tar, and other substances can cause lung cancer. The risk is highest for those with years of exposure. The risk of lung cancer from these substances is even higher for smokers.
  • Air pollution: Air pollution may slightly increase the risk of lung cancer. The risk from air pollution is higher for smokers.
  • Family history of lung cancer: People with a father, mother, brother, or sister who had lung cancer may be at slightly increased risk of the disease, even if they don't smoke.
  • Personal history of lung cancer: People who have had lung cancer are at increased risk of developing a second lung tumor.
  • Age over 65: Most people are older than 65 years when diagnosed with lung cancer.

Researchers have studied other possible risk factors. For example, having certain lung diseases (such as tuberculosis or bronchitis) for many years may increase the risk of lung cancer. It's not yet clear whether having certain lung diseases is a risk factor for lung cancer.

People who think they may be at risk for developing lung cancer should talk to their doctor. The doctor may be able to suggest ways to reduce their risk and can plan an appropriate schedule for checkups. For people who have been treated for lung cancer, it's important to have checkups after treatment. The lung tumor may come back after treatment, or another lung tumor may develop.

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  • a cough that gets worse or does not go away
  • breathing trouble, such as shortness of breath
  • constant chest pain
  • coughing up blood
  • a hoarse voice
  • frequent lung infections, such as pneumonia
  • feeling very tired all the time
  • weight loss with no known cause


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If you have a symptom that suggests lung cancer, your doctor must find out whether it's from cancer or something else. Your doctor may ask about your personal and family medical history. Your doctor may order blood tests, and you may have one or more of the following tests:

  • Chest X-ray: X-ray pictures of your chest may show tumors or abnormal fluid.

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Your doctor may refer you to a specialist who has experience treating lung cancer, or you may ask for a referral. You may have a team of specialists. Specialists who treat lung cancer include thoracic (chest) surgeons, thoracic surgical oncologists, medical oncologists, and radiation oncologists. Your health care team may also include a pulmonologist (a lung specialist), a respiratory therapist, an oncology nurse, and a registered dietitian.

Lung cancer is hard to control with current treatments. For that reason, many doctors encourage patients with this disease to consider taking part in a clinical trial. Clinical trials are an important option for people with all stages of lung cancer. See "The Promise of Cancer Research."


People with limited stage small cell lung cancer usually have radiation therapy and chemotherapy. For a very small lung tumor, a person may have surgery and chemotherapy. Most people with extensive stage small cell lung cancer are treated with chemotherapy only.

People with non-small cell lung cancer may have surgery, chemotherapy, radiation therapy, or a combination of treatments. The treatment choices are different for each stage. Some people with advanced cancer receive targeted therapy.

Cancer treatment is either local therapy or systemic therapy:

  • Local therapy: Surgery and radiation therapy are local therapies. They remove or destroy cancer in the chest. When lung cancer has spread to other parts of the body, local therapy may be used to control the disease in those specific areas. For example, lung cancer that spreads to the brain may be controlled with radiation therapy to the head.
  • Systemic therapy: Chemotherapy and targeted therapy are systemic therapies. The drugs enter the bloodstream and destroy or control cancer throughout the body.





The surgeon removes part or all of the lung:

  • All of the lung (pneumonectomy): The surgeon removes the entire lung.

After lung surgery, air and fluid collect in the chest. A chest tube allows the fluid to drain. A nurse or respiratory therapist will teach you coughing and breathing exercises. You'll need to do the exercises several times a day.



Radiation Therapy


You may receive external radiation. This is the most common type of radiation therapy for lung cancer. The radiation comes from a large machine outside your body. Most people go to a hospital or clinic for treatment. Treatments are usually 5 days a week for several weeks.

Another type of radiation therapy is internal radiation (brachytherapy). Internal radiation is seldom used for people with lung cancer. The radiation comes from a seed, wire, or another device put inside your body.

The side effects depend mainly on the type of radiation therapy, the dose of radiation, and the part of your body that is treated. External radiation therapy to the chest may harm the esophagus, causing problems with swallowing. You may also feel very tired. In addition, your skin in the treated area may become red, dry, and tender. After internal radiation therapy, a person may cough up small amounts of blood.

Your doctor can suggest ways to ease these problems.



Usually, more than one drug is given. Anticancer drugs for lung cancer are usually given through a vein (intravenous). Some anticancer drugs can be taken by mouth.

Chemotherapy is given in cycles. You have a rest period after each treatment period. The length of the rest period and the number of cycles depend on the anticancer drugs used.


The side effects depend mainly on which drugs are given and how much. The drugs can harm normal cells that divide rapidly:

  • Blood cells: When chemotherapy lowers your levels of healthy blood cells, you're more likely to get infections, bruise or bleed easily, and feel very weak and tired. Your health care team gives you blood tests to check for low levels of blood cells. If the levels are low, there are medicines that can help your body make new blood cells.
  • Cells in hair roots: Chemotherapy may cause hair loss. Your hair will grow back after treatment ends, but it may be somewhat different in color and texture.
  • Cells that line the digestive tract: Chemotherapy can cause poor appetite, nausea and vomiting, diarrhea, or mouth and lip sores. Ask your health care team about treatments that help with these problems.

Some drugs for lung cancer can cause hearing loss, joint pain, and tingling or numbness in your hands and feet. These side effects usually go away after treatment ends.

When radiation therapy and chemotherapy are given at the same time, the side effects may be worse.

Targeted Therapy

Targeted therapy uses drugs to block the growth and spread of cancer cells. The drugs enter the bloodstream and can affect cancer cells all over the body. Some people with non-small cell lung cancer that has spread receive targeted therapy.

There are two kinds of targeted therapy for lung cancer:

  • One kind is given through a vein (intravenous) at the doctor's office, hospital, or clinic. It's given at the same time as chemotherapy. The side effects may include bleeding, coughing up blood, a rash, high blood pressure, abdominal pain, vomiting, or diarrhea.
  • Another kind of targeted therapy is taken by mouth. It isn't given with chemotherapy. The side effects may include rash, diarrhea, and shortness of breath.

During treatment, your health care team will watch for signs of problems. Side effects usually go away after treatment ends.

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Cancer reference provided by the web site of the National Cancer Institute ( The NCI Web site is periodically revised, and content may be deleted or moved. We try to ensure that existing links will redirect to the new page(s).

Cancer Guide