Small-cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) are the two main types of lung cancer. SCLC typically spreads more quickly and is more aggressive than NSCLC.

Lung cancer — including both SCLC and NSCLC — is the third most common form of cancer among adults in the United States. Lung cancers account for about 12% of new cancer diagnoses.

Learn the differences between the two types, including stages, treatment options, and outlook.

In a person with SCLC, cancerous cells appear small and round under a microscope. The cells of NSCLC are larger.

Both SCLC and NSCLC have several subtypes. More common NSCLC subtypes include:

  • adenocarcinoma
  • squamous cell carcinoma
  • large cell carcinoma

While SCLC also has subtypes, researchers do not typically distinguish between them.

Some NSCLC subtypes may be more aggressive than others, but generally, SCLC is more aggressive than NSCLC.

Smoking is a major risk factor for both types of lung cancer. Very few people who have never smoked receive a diagnosis of SCLC.


If a person consults a doctor about possible symptoms of lung cancer, the doctor may ask questions, take a medical history, and perform a physical examination.

If they suspect lung cancer, the doctor may request imaging scans, such as an X-ray or CT scan, and look for signs of a tumor, scarring, or a buildup of fluid.

They may also request samples of phlegm to perform a sputum test. This can indicate whether cancer is present. The doctor may ask the person to provide a sample every morning for 3 days in a row.

Doctors may also perform a biopsy. This involves using a needle to take a sample of cells from the lungs for examination under a microscope. They may do this during surgery.

A biopsy can show whether cells are cancerous and what type of cancer is present, if any.

Sometimes, the doctor requests a bronchoscopy. This procedure involves inserting a tool with a built-in camera through the mouth or nose and into the lungs. This helps healthcare professionals see the area and take tissue samples.

Healthcare professionals may also carry out other tests to determine whether the cancer has spread beyond the lungs.

What does lung cancer look like? Find out more.

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SCLC and NSCLC have similar symptoms. Sometimes, symptoms do not appear until the cancer reaches a later stage.

Possible symptoms include:

  • hoarse voice
  • persistent cough
  • fatigue
  • shortness of breath and wheezing
  • difficulty swallowing
  • loss of appetite
  • chest pain and discomfort
  • a cough that brings up bloody mucus
  • swelling in the veins of the face and neck

Although the symptoms of the two types are similar, SCLC spreads more rapidly.

A person may be more likely to experience symptoms once lung cancer has reached a later stage.

Does lung cancer affect women differently? Learn more.

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The causes and risk factors for SCLC and NSCLC tend to be similar.

Smoking is the main risk factor. Cigarette smoke and the chemicals it contains can damage the lungs, leading to cellular changes that may result in cancer.

Additional risk factors include:

  • exposure to secondhand smoke
  • significant air pollution in the local area
  • older age
  • past exposure to radiation
  • exposure to arsenic and other chemicals, such as radon
  • exposure to asbestos, nickel, chromium, soot, or tar
  • a family history of lung cancer
  • HIV

Smoking is a major risk factor for lung cancer. Find some ideas for how to quit.

The stage of cancer describes how far it has spread within the body.

There are different ways to describe the stages. One simple way is:

  • In situ: Healthcare professionals have detected abnormal cells, but these cells have not yet become cancerous or spread.
  • Localized: The cancer is in only one place in the body.
  • Regional: The cancer has spread to nearby tissues or lymph nodes.
  • Distant: The cancer has spread to other parts of the body, such as the bones, brain, liver, or the other lung.
  • Unknown: There is not enough information to determine the stage.

However, each type of lung cancer has its own specific method of staging.

Stages of NSCLC

For this type of cancer, doctors typically use a 5-stage system:

  • Stage 0: Similar to “in situ,” this means a doctor cannot detect cancerous cells through traditional imaging methods, but tests have revealed precancerous cells in the mucus or elsewhere in the body.
  • Stage 1: The cancer is in the lungs only.
  • Stage 2: The cancer has reached nearby lymph nodes or has grown larger than in stage 1 without spreading to the lymph nodes.
  • Stage 3: The cancer has spread to other lymph nodes in the chest, possibly to those in the middle or on the other side of the chest.
  • Stage 4: The cancer is present in both lungs, in other parts of the body, or both.

Stages of SCLC

Doctors generally categorize SCLC into one of two stages:

  • The limited stage: The cancer is on one side of the chest. It may be in one lung and possibly in nearby lymph nodes.
  • The extensive stage: The cancer has spread either to the other lung or to other organs outside the original tumor.

Some doctors use further staging for SCLC.

Can a person have both types?

Researchers estimate that 5–28% of SCLC cases are “mixed.” This means the person has both SCLC and NSCLC. Research suggests that mixed lung cancer may be easier to treat than SCLC alone.

After making a diagnosis, a doctor can describe the treatment options and develop a treatment plan.

Factors that affect the plan include:

  • the type of cancer
  • how far it has spread
  • the person’s age and overall health
  • the availability of therapies
  • personal preferences

Each person’s situation is different, and treatment will vary accordingly.

NSCLC treatment options

Treatment options for NSCLC include:

  • Surgery: A surgeon removes cancerous cells and any nearby lymph nodes that the cancer may affect. If cancer affects a large portion of the lungs, surgery may not be possible.
  • Radiation therapy: A radiologist directs a beam of radiation toward cancerous cells to destroy them.
  • Chemotherapy: A doctor gives a person powerful drugs that can kill cancer cells.
  • Endoscopic stents: If a tumor has blocked part of the airway, a surgeon may insert a stent to keep the airway open.
  • Targeted treatments: These drugs target specific genes or other factors that enhance cancer’s ability to grow. Blocking these factors can help stop or delay the growth of some types of cancer.
  • Immunotherapy: This treatment aims to boost the immune system’s ability to defend the body against cancer.

SCLC treatment options

For SCLC, treatment mainly aims to manage the disease.

Options include:

  • chemotherapy, which is the main treatment
  • radiation therapy, which may help boost the effectiveness of chemotherapy or help prevent the cancer from spreading to the brain
  • a combination of surgery and chemotherapy — doctors will use this approach when the cancer has not yet reached the lymph nodes, which is rare
  • immunotherapy

Doctors may use a combination of treatments for lung cancer, depending on the person’s needs, the stage of cancer, and the tumor’s location. Treatment may also include palliative care, or procedures and medications to relieve symptoms and improve a person’s quality of life.

Experts use past statistics to estimate the percentage of people who are likely to live for 5 or more years after a diagnosis of cancer. These estimations are called survival rates.

They represent averages and do not account for factors such as a person’s age or overall health.

Researchers developed the following survival rates for 2023 based on people who received a lung cancer diagnosis between 2012 and 2018.

NSCLC survival rates

For NSCLC, the American Cancer Society (ACS) reports the following 5-year relative survival rates:

  • Localized cancer: 65%
  • Regional cancer: 37%
  • Distant cancer: 9%

The overall average likelihood of living for at least 5 years after NSCLC diagnosis is 28%.

SCLC survival rates

The ACS estimates the following 5-year survival rates for people with SCLC:

  • Localized cancer: 30%
  • Regional cancer: 18%
  • Distant cancer: 3%

The overall average likelihood of living for at least 5 years after a diagnosis of SCLC is 7%.

Other factors that may affect survival rates include a person’s age and whether the cancer has come back after treatment. Recurring cancer and advanced age can have a negative effect on survival rates.

People who receive a diagnosis of NSCLC or SCLC now may have a better outlook than these numbers show, based on improved treatments and other factors.

There are two main types of lung cancer: small-cell and non-small cell. Small-cell lung cancer is less common and more aggressive.

Quitting smoking — or never smoking at all — can significantly reduce the risk of developing any type of lung cancer.

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If a person has a diagnosis of small-cell lung cancer, how long can they usually expect to live?


It depends on the stage of the disease, but overall, the average survival rate is about 1–2 years.

Seunggu Han, MD Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

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