Non-small cell lung cancer is a disease in which malignant (cancer) cells form in the tissues of the lung.
The lungs are a pair of cone-shaped breathing organs in the chest. The lungs bring oxygen into the body as you breathe in. They release carbon dioxide, a waste product of the body’s cells, as you breathe out. Each lung has sections called lobes. The left lung has two lobes. The right lung is slightly larger and has three lobes. Two tubes called bronchi lead from the trachea (windpipe) to the right and left lungs. The bronchi are sometimes also involved in lung cancer. Tiny air sacs called alveoli and small tubes called bronchioles make up the inside of the lungs.
A thin membrane called the pleura covers the outside of each lung and lines the inside wall of the chest cavity. This creates a sac called the pleural cavity. The pleural cavity normally contains a small amount of fluid that helps the lungs move smoothly in the chest when you breathe.
There are two main types of lung cancer: non-small cell lung cancer and small cell lung cancer.
See the following PDQ summaries for more information about lung cancer:
There are several types of non-small cell lung cancer.
Each type of non-small cell lung cancer has different kinds of cancer cells. The cancer cells of each type grow and spread in different ways. The types of non-small cell lung cancer are named for the kinds of cells found in the cancer and how the cells look under a microscope:
Other less common types of non-small cell lung cancer are: pleomorphic, carcinoid tumor, salivary gland carcinoma, and unclassified carcinoma.
Smoking increases the risk of non-small cell lung cancer.
Smoking cigarettes, pipes, or cigars is the most common cause of lung cancer. The earlier in life a person starts smoking, the more often a person smokes, and the more years a person smokes, the greater the risk of lung cancer. If a person has stopped smoking, the risk becomes lower as the years pass.
Anything that increases your chance of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. Talk with your doctor if you think you may be at risk.
Risk factors for lung cancer include the following:
When smoking is combined with other risk factors, the risk of lung cancer is increased.
Tests that examine the lungs are used to detect (find), diagnose, and stage non-small cell lung cancer.
Tests and procedures to detect, diagnose, and stage non-small cell lung cancer are often done at the same time. Some of the following tests and procedures may be used:
Signs of non-small cell lung cancer include a cough that doesn't go away and shortness of breath.
Sometimes lung cancer does not cause any signs or symptoms. It may be found during a chest x-ray done for another condition. Signs and symptoms may be caused by lung cancer or by other conditions. Check with your doctor if you have any of the following:
There are different types of treatment for patients with non-small cell lung cancer.
Different types of treatments are available for patients with non-small cell lung cancer. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment. Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.
Nine types of standard treatment are used:
Four types of surgery are used to treat lung cancer:
Wedge resection: Surgery to remove a tumor and some of the normal tissue around it. When a slightly larger amount of tissue is taken, it is called a segmental resection.
Even if the doctor removes all the cancer that can be seen at the time of the surgery, some patients may be given chemotherapy or radiation therapy after surgery to kill any cancer cells that are left. Treatment given after the surgery, to lower the risk that the cancer will come back, is called adjuvant therapy.
Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer.
Radiosurgery is a method of delivering radiation directly to the tumor with little damage to healthy tissue. It does not involve surgery and may be used to treat certain tumors in patients who cannot have surgery.
The way the radiation therapy is given depends on the type and stage of the cancer being treated. It also depends on where the cancer is found. For tumors in the airways, radiation is given directly to the tumor through an endoscope.
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the cerebrospinal fluid, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.
See Drugs Approved for Non-Small Cell Lung Cancer for more information.
Targeted therapy is a type of treatment that uses drugs or other substances to attack specific cancer cells. Targeted therapies usually cause less harm to normal cells than chemotherapy or radiation therapy do. Monoclonal antibodies and small-molecule tyrosine kinase inhibitors are the two main types of targeted therapy being used in the treatment of non-small cell lung cancer.
Monoclonal antibody therapy is a cancer treatment that uses antibodies made in the laboratory from a single type of immune system cell. These antibodies can identify substances on cancer cells or normal substances in the blood or tissues that may help cancer cells grow. The antibodies attach to the substances and kill the cancer cells, block their growth, or keep them from spreading. Monoclonal antibodies are given by infusion. They may be used alone or to carry drugs, toxins, or radioactive material directly to cancer cells.
Monoclonal antibodies used to treat non-small cell lung cancer include bevacizumab and cetuximab. Bevacizumab binds to vascular endothelial growth factor (VEGF) in the blood and tissues and may prevent the growth of new blood vessels that tumors need to grow. Cetuximab is a monoclonal antibody that acts as a tyrosine kinase inhibitor. It binds to epidermal growth factor receptor (EGFR), which is a tyrosine kinase protein, on the surface of cancer cells and works to stop the cells from growing and dividing.
Small-molecule tyrosine kinase inhibitors are targeted therapy drugs that work inside cancer cells and block signals needed for tumors to grow. Small-molecule tyrosine kinase inhibitors may be used with other anticancer drugs as adjuvant therapy.
Small-molecule tyrosine kinase inhibitors used to treat non-small cell lung cancer include erlotinib and gefitinib. They are types of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors.
Crizotinib is another type of small-molecule tyrosine kinase inhibitor that is used to treat non-small cell lung cancer. It is used to treat non-small cell lung cancer that has certain mutations (changes) in the anaplastic lymphoma kinase (ALK) gene. The protein made by the ALK gene has tyrosine kinase activity.
See Drugs Approved for Non-Small Cell Lung Cancer for more information.
Laser therapy is a cancer treatment that uses a laser beam (a narrow beam of intense light) to kill cancer cells.
Photodynamic therapy (PDT)
Photodynamic therapy (PDT) is a cancer treatment that uses a drug and a certain type of laser light to kill cancer cells. A drug that is not active until it is exposed to light is injected into a vein. The drug collects more in cancer cells than in normal cells. Fiberoptic tubes are then used to carry the laser light to the cancer cells, where the drug becomes active and kills the cells. Photodynamic therapy causes little damage to healthy tissue. It is used mainly to treat tumors on or just under the skin or in the lining of internal organs. When the tumor is in the airways, PDT is given directly to the tumor through an endoscope.
Cryosurgery is a treatment that uses an instrument to freeze and destroy abnormal tissue, such as carcinoma in situ. This type of treatment is also called cryotherapy. For tumors in the airways, cryosurgery is done through an endoscope.
Electrocautery is a treatment that uses a probe or needle heated by an electric current to destroy abnormal tissue. For tumors in the airways, electrocautery is done through an endoscope.
Watchful waiting is closely monitoring a patient’s condition without giving any treatment until signs or symptoms appear or change. This may be done in certain rare cases of non-small cell lung cancer.
New types of treatment are being tested in clinical trials.
This summary section describes treatments that are being studied in clinical trials. It may not mention every new treatment being studied. Information about clinical trials is available from the NCI Web site.
Chemoprevention is the use of drugs, vitamins, or other substances to reduce the risk of cancer or to reduce the risk cancer will recur (come back).
New combinations of treatments are being studied in clinical trials.
Patients may want to think about taking part in a clinical trial.
For some patients, taking part in a clinical trial may be the best treatment choice. Clinical trials are part of the cancer research process. Clinical trials are done to find out if new cancer treatments are safe and effective or better than the standard treatment.
Many of today's standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.
Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.
Patients can enter clinical trials before, during, or after starting their cancer treatment.
Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment.
Clinical trials are taking place in many parts of the country. See the Treatment Options section that follows for links to current treatment clinical trials. These have been retrieved from NCI's listing of clinical trials.
Follow-up tests may be needed.
Some of the tests that were done to diagnose the cancer or to find out the stage of the cancer may be repeated. Some tests will be repeated in order to see how well the treatment is working. Decisions about whether to continue, change, or stop treatment may be based on the results of these tests.
Some of the tests will continue to be done from time to time after treatment has ended. The results of these tests can show if your condition has changed or if the cancer has recurred (come back). These tests are sometimes called follow-up tests or check-ups.