Small Cell Lung Cancer

by National Cancer Institute

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 that are found within the chest. The lungs bring oxygen into the body when breathing in and take out carbon dioxide when breathing out. Each lung has sections called lobes. The left lung has two lobes. The right lung, which is slightly larger, has three. A thin membrane called the pleura surrounds the lungs. Two tubes called bronchi lead from the trachea (windpipe) to the right and left lungs. The bronchi are sometimes also involved in lung cancer. Small tubes called bronchioles and tiny air sacs called alveoli make up the inside of the lungs.

There are three types of small cell lung cancer.

These three types include many different types of cells. The cancer cells of each type grow and spread in different ways. The types of small cell lung cancer are named for the kinds of cells found in the cancer and how the cells look when viewed under a microscope:

• Small cell carcinoma (oat cell cancer).
• Mixed small cell/large cell carcinoma.
• Combined small cell carcinoma.

Smoking tobacco is the major risk factor for developing small cell lung cancer.

Cigarette smoking is the most common cause of lung cancer. Risk factors for small cell lung cancer include:

• Smoking cigarettes, cigars, or pipes now or in the past.
• Being exposed to second hand smoke.
• Being exposed to asbestos or radon.

Possible signs of small cell lung cancer include coughing, chest pain, and shortness of breath.

These and other symptoms may be caused by small cell lung cancer or by other conditions. A doctor should be consulted if any of the following problems occur:

• A cough that doesn't go away.
• Shortness of breath.
• Chest pain that doesn't go away.
• Wheezing.
• Coughing up blood.
• Hoarseness.
• Swelling of the face and neck.
• Loss of appetite.
• Unexplained weight loss.
• Unusual tiredness.

Tests and procedures that examine the lungs are used to detect (find) and diagnose small cell lung cancer.

The following tests and procedures may be used:

• Chest x-ray
• Physical exam and history
• Sputum cytology
• Laboratory tests
• Bronchoscopy

Fine needle aspiration biopsy: The removal of part of a lump, suspicious tissue, or fluid, using a thin needle. A pathologist views the tissue or fluid under a microscope to look for cancer cells. This procedure is also called a needle biopsy.

Thoracentesis: Removal of fluid from the pleural cavity (the space between the lungs and chest wall) through a needle inserted between the ribs.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) and treatment options depend on the following:

• The stage of the cancer (whether it is in the chest cavity only or has spread to other places in the body).
• The patient's gender and general health.
• The blood level of lactate dehydrogenase (LDH), a substance found in the blood that may indicate cancer when the level is higher than normal.

For most patients with small cell lung cancer, current treatments do not cure the cancer.

If lung cancer is found, participation in one of the many clinical trials being done to improve treatment should be considered. Clinical trials are taking place in most parts of the country for patients with all stages of small cell lung cancer.

Stages of Small Cell Lung Cancer

After small cell lung cancer has been diagnosed, tests are done to find out if cancer cells have spread within the chest or to other parts of the body.

The process used to find out if cancer has spread within the chest or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment. The following tests and procedures may be used in the staging process:

• Bone marrow biopsy
• CT scan (CAT scan) of brain, chest, and abdomen
• MRI (magnetic resonance imaging)
• Radionuclide bone scan
• PET scan (positron emission tomography scan)

The following stages are used for small cell lung cancer:

Limited-Stage Small Cell Lung Cancer

In limited-stage, cancer is found in one lung, the tissues between the lungs, and nearby lymph nodes only.

Extensive-Stage Small Cell Lung Cancer

In extensive-stage, cancer has spread outside of the lung in which it began or to other parts of the body.

Recurrent Small Cell Lung Cancer

Recurrent small cell lung cancer is cancer that has recurred (come back) after it has been treated. The cancer may come back in the chest, central nervous system, or in other parts of the body.

Treatment Options by Stage

Limited-Stage Small Cell Lung Cancer

Treatment of limited-stage small cell lung cancer may include the following:

• Combination chemotherapy and radiation therapy to the chest, with or without radiation therapy to the brain.
• Combination chemotherapy with or without radiation therapy to the brain in patients with complete response.
• Combination chemotherapy with or without radiation therapy to the chest.
• Surgery followed by chemotherapy or chemotherapy plus radiation therapy to the chest, with or without radiation therapy to the brain.
• Clinical trials of new chemotherapy, surgery, and radiation treatments.

This summary refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied.

Extensive-Stage Small Cell Lung Cancer

Treatment of extensive-stage small cell lung cancer may include the following:

• Chemotherapy.
• Combination chemotherapy.
• Combination chemotherapy with or without radiation therapy to the brain for patients with complete response.
• Radiation therapy to the brain, spine, bone, or other parts of the body where the cancer has spread, as palliative therapy to relieve symptoms and improve quality of life.
• Clinical trials of new chemotherapy treatments.

This summary refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied.

Treatment Options for Recurrent Small Cell Lung Cancer

Treatment of recurrent small cell lung cancer may include the following:

• Radiation therapy as palliative therapy to relieve symptoms and improve quality of life.
• Chemotherapy as palliative therapy to relieve symptoms and improve quality of life.
• Laser therapy, surgical placement of devices to keep the airways open, and/or internal radiation therapy, as palliative therapy to relieve symptoms and improve quality of life.
• Clinical trials of chemotherapy.

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