Small Cell Lung Cancer (SCLC)
A fast-growing lung cancer strongly linked to smoking
Quick Facts
- Type: Aggressive lung cancer
- Main cause: Cigarette smoking
- Behavior: Grows and spreads quickly
- Main treatment: Chemotherapy and radiation
Overview
Small cell lung cancer (SCLC) is one of the two main types of lung cancer. It is named for the small, round cancer cells seen under the microscope. SCLC tends to grow quickly and spread to other parts of the body early, often before symptoms appear, which makes early detection difficult.
SCLC is strongly associated with cigarette smoking and is uncommon in people who have never smoked. Although it is aggressive, it often responds well at first to chemotherapy and radiation. Doctors usually describe it as either limited stage (confined to one side of the chest) or extensive stage (spread more widely), which guides treatment.
Symptoms
Symptoms often develop quickly and may already reflect spread of the cancer. Common signs include:
- A new or worsening cough that does not go away
- Coughing up blood or rust-colored phlegm
- Shortness of breath or wheezing
- Chest pain
- Hoarseness, fatigue, and unintended weight loss
- Swelling of the face, neck, or arms if a large vein in the chest is blocked
Some people develop unusual hormone-related effects (paraneoplastic syndromes), such as low sodium or muscle weakness, because SCLC cells can release hormone-like substances.
Causes
SCLC develops when cells in the lung's airways acquire genetic changes that cause them to grow uncontrollably. The dominant cause is tobacco smoke, which damages the lining of the airways over time. Contributing factors include:
- Cigarette smoking: By far the leading cause, including current and past smoking.
- Secondhand smoke: Long-term exposure to others' smoke.
- Radon gas: A radioactive gas that can build up in homes.
- Workplace exposures: Substances such as asbestos and certain chemicals.
The risk rises with the amount and duration of smoking, but quitting at any time lowers future risk.
Risk Factors
- Current or past cigarette smoking, especially heavy or long-term use
- Exposure to secondhand smoke
- Radon exposure in the home
- Workplace exposure to asbestos, arsenic, or other carcinogens
- Previous radiation therapy to the chest
- A family history of lung cancer
Diagnosis
Diagnosis combines imaging, sampling of tissue, and staging tests. These may include:
- Imaging: Chest X-ray and CT scan to find a tumor and check the chest.
- Biopsy: A sample of tissue, often taken through a bronchoscope or with a needle, to confirm the cell type.
- Staging scans: PET, brain MRI, and other imaging to see whether the cancer has spread.
- Blood tests: To assess overall health and check for hormone-related effects.
Treatment
Because SCLC usually spreads early, treatment most often relies on medicines and radiation rather than surgery. Options include:
- Chemotherapy: The mainstay of treatment, often combined for both limited and extensive stage disease.
- Immunotherapy: Drugs that help the immune system fight cancer, often added to chemotherapy for extensive stage.
- Radiation therapy: To the chest for limited stage and sometimes to the brain to prevent or treat spread there.
- Surgery: Used only rarely, for very small, early tumors.
- Supportive (palliative) care: To manage symptoms, breathing, pain, and quality of life at any stage.
SCLC often shrinks substantially with initial treatment, but it can return, so ongoing follow-up is important.
Prevention
- Do not smoke; if you do, quitting at any age lowers risk
- Avoid secondhand smoke
- Test your home for radon and reduce high levels
- Limit workplace exposure to asbestos and other carcinogens
- Discuss low-dose CT lung cancer screening with your doctor if you have a heavy smoking history
When to See a Doctor
See a doctor for a cough that lasts more than a few weeks, coughing up blood, persistent chest pain, or unexplained weight loss—especially if you smoke or used to. Seek emergency care for:
- Severe shortness of breath or difficulty breathing
- Coughing up large amounts of blood
- Sudden swelling of the face and neck with trouble breathing
- Severe weakness, confusion, or fainting
Frequently Asked Questions
How is small cell lung cancer different from other lung cancers?
Small cell lung cancer grows and spreads faster than the more common non-small cell type and is more strongly tied to smoking. Because it spreads early, it is usually treated with chemotherapy, immunotherapy, and radiation rather than surgery.
What causes small cell lung cancer?
The leading cause is cigarette smoking, which damages the airways over many years. Secondhand smoke, radon gas, and certain workplace exposures such as asbestos also raise the risk. It is uncommon in people who have never smoked.
Can small cell lung cancer be cured?
Limited stage disease can sometimes be controlled for a long time with chemotherapy and radiation, and a minority of people do well long term. Extensive stage disease is harder to cure, but treatment can shrink the cancer, ease symptoms, and extend life.
What are the first symptoms?
Early signs include a persistent or worsening cough, coughing up blood, shortness of breath, chest pain, fatigue, and unintended weight loss. Symptoms often appear only after the cancer has begun to spread.
Is small cell lung cancer screening available?
Yes. People with a heavy smoking history may qualify for low-dose CT lung cancer screening, which can catch lung cancers earlier. Talk to your doctor about whether screening is right for you.
References
- National Cancer Institute (NCI). Small cell lung cancer treatment.
- American Cancer Society. Small cell lung cancer.
- Mayo Clinic. Lung cancer — Symptoms and causes.
- Centers for Disease Control and Prevention (CDC). Lung cancer.