What Is Extensive Small-Cell Lung Cancer?

Medically Reviewed by Sabrina Felson, MD on March 21, 2023

This cancer is called small cell based on the size and shape of the cells under a microscope. It starts in hormone-producing cells of the lung. The cells change and start to grow out of control.

Your doctor will describe your cancer as limited or extensive, depending on where the diseased cells have spread. If they haven’t moved beyond one of your lungs or the nearby lymph nodes, it’s limited. Once they move into these areas, it’s extensive.

How Common Is Extensive Small-Cell Lung Cancer?

If you have extensive small-cell lung cancer, this means the disease is already spread. Doctors diagnose small-cell lung cancer in about 15% of the nearly 230,000 new lung cancer cases in the U.S. each year.

About 1 in 3 people with this condition find out that they have it in the early, or limited stage. But most get their diagnosis when it’s already advanced. This is because small cell moves very quickly. By the time you learn you have it, it may already have spread to the other side of your chest. In some cases, it may already be in other parts of your body as well, like your liver or bones. 


Early on, you may have few or even no symptoms. Later on, you may:

  • Have a cough you can’t shake
  • Struggle to take a deep breath

Once the condition becomes more advanced, it can affect other parts of your body. You may:

  • Notice a yellowish color to your eyes or skin if it has spread to your liver
  • Have bad headaches or dizziness if it’s in your brain
  • Lose weight
  • Have bone pain
  • Have nerve or neurologic problems

Small-cell lung cancer also may make hormones. Or the cancer may scramble your immune system so it attacks healthy cells instead of the cancer cells. Roughly 1 in 5 people with cancer may have these effects, called paraneoplastic syndromes.

More than half of the time, symptoms appear before your cancer is diagnosed. Since these symptoms involve other organs, your doctor may at first suspect some other cause than lung cancer. The symptoms of a paraneoplastic syndrome depend on the organ that’s affected. You may have:

  • Fever
  • Sweating at night
  • Loss of appetite
  • Weight loss you can’t explain

More rarely, you’ll have:

  • Skin problems, such as itching, redness, and growths
  • Dizziness, double vision, difficulty speaking, loss of coordination
  • High blood pressure, weakness

Who’s at Risk?

The one thing that makes you most likely to develop this disease is having smoked or used tobacco in the past. Heavy smokers face the greatest risk. Your chances also go up if you’ve lived with someone who smoked.

Several other things can raise your chances of developing this illness:

  • Exposure to chemicals like asbestos and arsenic
  • Living in an area with a lot of air pollution
  • Exposure to more radiation than normal through (prolonged) medical treatment or tests such as CT scans

What Else Should I Know?

Fewer people these days are diagnosed with small-cell lung cancer. One reason may be that fewer people smoke. There’s also less tar in cigarettes on the market. If you do smoke, there are still payoffs to quitting after your diagnosis. Not only will you feel better, but it will be easier for you to get through treatment. It may also extend your life.  

When your cancer is extensive, it will be hard to get rid of all of it. You may get chemotherapy and radiation, as that appears to treat small-cell lung cancer better than other types.  

In recent years, researchers have been doing more to find better ways to treat this less common form of lung cancer. It’s impossible to predict outcomes for every person, but with current treatments, people with extensive small-cell lung cancer can often live 6 to 12 months. You may want to talk to your doctor early on about whether you qualify for a research study. This will give you more options for treatment.

Show Sources

SOURCES: “Lung Cancer - Small Cell: Introduction.”

Journal of Clinical Oncology: “Changing Epidemiology of Small-Cell Lung Cancer in the United States Over the Last 30 Years: Analysis of the Surveillance, Epidemiologic, and End Results Database.”

Memorial Sloan Kettering Cancer Center: “Small Cell Lung Cancer.”

National Cancer Institute: “Dictionary of Cancer Terms,” “Small Cell Lung Cancer Treatment (PDQ®)–Health Professional Version.”

National Organization for Rare Disorders: “Small Cell Lung Cancer.”

UpToDate: “Patient education: Small cell lung cancer treatment (Beyond the Basics).”

Cleveland Clinic: “Paraneoplastic Syndromes.”

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