Small Cell Lung Cancer

What Is It?

Small cell lung cancer has been called oat cell cancer because the cells resemble oats when seen under a microscope. This cancer usually originates in the lung's large central airways (the bronchi). It accounts for about 20% of all lung cancers. In some cases, small cell tumors also include cells that have non small cell features. This condition is called a mixed tumor.

All types of lung cancer are associated strongly with smoking. About 90% of people who get small cell lung cancer are either current or past smokers.

Tumor cells may secrete adrenocorticotropic hormone, causing Cushing's disease, which might cause a puffy face, weight gain, hump on the lower neck or elevated blood sugar levels. Tumors may secrete antidiuretic hormone, leading to water retention and low sodium, which causes confusion. Small cell cancer can cause a specific type of weakness caused by antibodies produced as a result of the cancer.

Small cell lung cancer is among the fastest growing cancers. In two-thirds of people with this cancer, the cancer already has spread (metastasized) by the time of diagnosis. The cancer can spread easily because of the constant flow of fluids through the lungs. These fluids consist of blood and lymph (a protein-filled fluid from the lymphatic system). The fluids can carry cancer cells to lymph nodes, the heart, the other lung and to organs outside of the chest. Small cell lung cancers spread most commonly to the brain, liver, adrenal glands and bone.

Symptoms

Although some cancers do not have any symptoms at first, others are diagnosed during an evaluation for any of the following:

• A persistent cough
• Coughing up blood (hemoptysis)
• Shortness of breath or wheezing
• Unexplained weight loss or loss of appetite
• Fatigue
• Difficulty swallowing
• Pain in the chest, shoulder or arm
• Bone pain
• Hoarseness
• Headaches, confusion or seizures
• Swelling of the face, neck or upper extremities

Diagnosis

Lung cancer often is discovered on a chest X-ray, where it appears as a gray or whitish area. Other imaging studies, such as computed tomography (CT) or magnetic resonance imaging (MRI), can further determine the size, shape and location of the tumor, and locate areas where the tumor has spread. This helps to find the best place to obtain a sample of the tumor to diagnose small cell versus other types of lung cancer, such as squamous cell or adenocarcinoma of the lung. The type of cancer determines the treatment.

Small cell lung cancer sometimes can be diagnosed with a technique called sputum cytology, in which mucus from the lungs (sputum) is examined under a microscope to check for abnormal cells. Cancer cells also can be found in the fluid between the lung and the chest wall (requiring a procedure that uses a needle to remove fluid) or in lymph nodes next to the lung (requiring a surgical procedure).

Another diagnostic technique is needle aspiration, in which fluid or tissue is removed (aspirated) from lymph nodes or suspicious masses. Cells also can be removed during bronchoscopy. A fiber optic viewing tube is inserted into the lung through the mouth and bronchial tubes. It allows the doctor to examine the tumor directly and to remove cells for examination.

In addition to the above tests, you may need a bone scan, bone marrow biopsy, CT scan of the head and additional biopsies to determine the degree of tumor spread. Small cell lung cancer has two stages:

• Limited cancer is confined to one lung and nearby lymph nodes.
• Extensive cancer has spread to both sides of the chest or beyond the chest.

Expected Duration

As with any cancer, even if small cell cancer disappears (goes into remission), there is a chance it can come back.

Prevention

Quit smoking and avoid secondhand smoke. Tobacco smoke is the main risk factor for small cell lung cancer. Although studies are trying to create reliable screening tests to diagnose lung cancer earlier, no test has been proven effective.

Treatment

Surgery rarely is done when small cell lung cancer is diagnosed because the cancer grows quickly and usually has already spread to many lymph nodes or beyond the lung. Because this cancer grows so rapidly, chemotherapy is the main therapy.

Treatment depends on the stage or degree of cancer spread. The earlier stage allows for more intense and effective radiation therapy within a small area.

For the best chances of remission, radiation therapy typically is combined with chemotherapy, in alternating cycles. If a person has many other serious medical problems or cannot tolerate high dose radiation or chemotherapy, he or she may be given altered doses to relieve specific symptoms such as bone pain. If tests show cancer remission at 6 to 12 weeks, some doctors will advise radiation to the brain to prevent the cancer from spreading there.

In people with extensive-stage cancer, radiation usually isn't used except to relieve specific symptoms, such as bone pain, that are caused by the spread of the tumor.

In rare cases, if the tumor has not spread to nearby lymph nodes, surgery is done to remove the tumor. This is more likely if the tumor is located at the edges of the lung instead of the more common central location. The chance for cure and prolonged survival is greater if surgery can be done, especially if chemotherapy is used as well.

When To Call A Professional

If you experience any symptoms of small cell lung cancer, make an appointment to see your health care professional as soon as possible.

Prognosis

Because small cell lung cancer grows and spreads so rapidly, the prognosis is poor. The 5-year survival rate is about 6%. The survival rate is higher when the disease is diagnosed and treated at the earlier, limited stage.

Even when treatment is successful initially, there is a high risk that the cancer will come back, often at a location different from where it was first seen.

Additional Info

National Cancer Institute (NCI)

U.S. National Institutes of Health

Public Inquiries Office

Building 31, Room 10A03

31 Center Drive, MSC 8322

Bethesda, MD 20892-2580

Phone: (301) 435-3848

Toll-Free: (800) 422-6237

TTY: (800) 332-8615

E-Mail: cancergovstaff@mail.nih.gov

http://www.nci.nih.gov/

American Cancer Society (ACS)

1599 Clifton Road, NE

Atlanta, GA 30329-4251

Toll-Free: (800) 227-2345

http://www.cancer.org/

American Lung Association

61 Broadway, 6th Floor

New York, NY 10006br />Phone: (212) 315-8700

Toll-Free: (800) 548-8252E-Mail: info@lungusa.org

http://www.lungusa.org/

National Heart, Lung, and Blood Institute (NHLBI)

P.O. Box 30105

Bethesda, MD 20824-0105

Phone: (301) 592-8573

TTY: (240) 629-3255

Fax: (301) 592-8563

E-Mail: nhlbiinfo@rover.nhlbi.nih.gov

http://www.nhlbi.nih.gov/

U.S. Environmental Protection Agency (EPA)

Ariel Rios Building

1200 Pennsylvania Ave., N.W.

Washington, DC 20460

Phone: (202) 272-0167

http://www.epa.gov/

National Institute for Occupational Safety and Health

4676 Columbia Parkway

Mail Stop C-18

Cincinnati, OH 45226

Toll-Free: (800) 356-4674

Fax: (513) 533-8573

http://www.cdc.gov/niosh/