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What Is
Small  Cell  Lung  Cancer?

Lung cancer starts when cancerous cells form in the tissues of the lung. There are 2 types of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). SCLC is named for the small, oval appearance of its cells under a microscope.1–3

SCLC is a fast-growing form of lung cancer and tends to spread quickly to other parts of the body, including the brain, liver, and bones, often before it has been diagnosed. Since SCLC grows quickly, it tends to respond well to chemotherapy and radiation therapy.1,4

How common is SCLC?

~30,000

people are diagnosed with SCLC  in the United States each year5

SCLC accounts for about

10% to 15%

of all lung cancers1

An open photo album.

Who develops SCLC?

Smoking is the most significant risk factor for developing SCLC. In fact, smoking is linked to about 95% of SCLC cases.5

Other risk factors may include6:

  • Exposure to secondhand smoke
  • Exposure to radon
  • Exposure to asbestos or other carcinogens
  • Family history of lung cancer

What are the symptoms of SCLC?

Symptoms of SCLC may include7:

  • A cough that doesn't go away or gets worse
  • Chest pain
  • Shortness of breath
  • Coughing up blood
  • Feeling tired or weak
  • Loss of appetite
  • Unexplained weight loss
  • Hoarseness
  • Swelling in the face and/or neck veins

Some people with SCLC may not experience any symptoms, especially in early stages. SCLC is often found when a chest X-ray or other imaging test is done for another reason.5

How fast does SCLC grow?

SCLC tends to grow and spread quickly. The prognosis depends on several factors, including the stage at diagnosis and overall health. Because SCLC is aggressive, it's important to start treatment as soon as possible.1,5

Small Cell Lung Cancer: What to Know downloadable pdf icon.

Small Cell Lung Cancer:
What to Know

A clear overview of SCLC—from diagnosis to what comes next.

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Stages of SCLC

Understand how SCLC develops.

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References

  1. American Cancer Society. What is lung cancer? Updated January 29, 2024. Accessed August 28, 2026. https://www.cancer.org/cancer/lung-cancer/about/what-is.html
  2. National Institutes of Health. National Cancer Institute. Small cell lung cancer treatment (PDQ®) – patient version. Updated May 8, 2025. Accessed August 17, 2026. https://www.cancer.gov/types/lung/patient/small-cell-lung-treatment-pdq
  3. National Institutes of Health. National Cancer Institute. NCI dictionary of cancer terms. Accessed August 31, 2026. https://www.cancer.gov/publications/dictionaries/cancer-terms
  4. American Cancer Society. Small cell lung cancer stages. Updated January 29, 2024. Accessed August 28, 2026. https://www.cancer.org/cancer/types/lung-cancer/detection-diagnosis-staging/staging-sclc.html
  5. National Organization for Rare Diseases. Small cell lung cancer. Published 2019. Updated October 31, 2023. Accessed August 28, 2026. https://rarediseases.org/rare-diseases/small-cell-lung-cancer/
  6. American Cancer Society. Lung cancer risk factors. Updated January 29, 2024. Accessed August 28, 2026. https://www.cancer.org/types/lung-cancer/causes-risks-prevention/risk-factors.html
  7. American Cancer Society. Signs and symptoms of lung cancer. Updated February 27, 2025. Accessed August 28, 2026. https://www.cancer.org/cancer/types/lung-cancer/detection-diagnosis-staging/signs-symptoms.html