Small Cell Lung Cancer

Small cell lung cancer (SCLC) accounts for about 15% of all lung cancers. In addition to existing treatment approaches, several promising new treatment approaches are being developed.

This website can help you:

  • Learn about small cell lung cancer
  • Understand the treatment options available for small cell lung cancer
  • Consider whether participating in a clinical trial might be right for you
  • Understand how to manage the side effects associated with lung cancer treatment

What is small cell lung cancer?

Small cell lung cancer is one of the major types of lung cancer. The other is non-small cell lung cancer. Small cell lung cancer cells look flat and smaller than normal, healthy cells. It is sometimes also called oat cell cancer.

Small cell lung cancer

Small cell lung cancer usually starts in the bronchiThe large air passages that lead from the trachea (windpipe) to the lungs in the center of the chest, although about 5% of the time it is found in the periphery of the lungs. Small cell lung cancer is a type of neuroendocrine tumor.1

Small cell lung cancer accounts for about 15% of all lung cancers, and is found most often in people with a history of tobacco use. Sometimes, non-small cell lung cancer (NSCLC)—another type of lung cancer—may change into small cell lung cancer after treatment with drugs such as tyrosine kinase inhibitors.2,3

Diagnosing small cell lung cancer

This type of lung cancer may be diagnosed in many different ways. In addition, doctors have come up with very specific modes of categorizing lung cancers to help treat them better. Understanding the ways that doctors categorize lung cancers may help you understand your diagnosis.

How is Small Cell Lung Cancer Diagnosed?

Many different tests are used to diagnose lung cancer and determine whether it has spread to other parts of the body. Some can also help to decide which treatments might work best. The steps and tests used in diagnosing small cell lung cancer include:

  • Imaging tests
  • Laboratory tests
  • Biopsies

Not all of these will be used for every person. The approaches used for an individual will depend on medical history and condition, symptoms, location of the nodule(s), and other test results.

Read the Diagnosing Lung Cancer section to learn about the different steps and tests for making a lung cancer diagnosis.

Stages of Lung Cancer

Staging is a way of describing where the cancer is located, if or where it has spread, and whether it is affecting other parts of the body. Doctors use diagnostics to determine the cancer’s stage, so staging may not be complete until all of the tests are finished. Knowing the stage helps the doctor to recommend a treatment plan.

Staging of small cell lung cancer is described in two different ways:4

  • Traditionally, the terms “limited stage” and “extensive stage” have been used
    • Limited stage means the cancer is only in the lung
    • Extensive stage means the cancer has spread widely throughout a lung, to the other lung, to lymph nodes on the other side of the chest, or to distant organs. Many doctors also call cancer that has spread to the fluid around the lung "extensive stage."
  • More recently, the same system that is used for non-small cell lung cancer is being used for small cell lung cancer
    • A number from one through four (I, II, III, or IV), based on the TNM system

About 30% of people diagnosed with small cell lung cancer have limited-stage disease at the time of their diagnosis.5

The Lung Cancer Staging section provides more information about this way of understanding small cell lung cancer.

Biomarker Profile

Lung cancer describes many different types of cancer that start in the lung or related structures. There are two different ways of describing what kind of lung cancer a person has:

  • Histology—what the cells look like under a microscope. Small cell lung cancer is a histological type of lung cancer. Non-small cell lung cancer is another histological type.
  • Biomarker profile (also called molecular profile, genomic profile, or signature profile)—the mutations, or characteristics, as well as any other unique biomarkers, found in a person’s cancer that allowed the cancer to grow.

A person’s lung cancer may or may not have one of the known mutations that drive small cell lung cancer. Known mutations in small cell lung cancer include TP53 and RB1. (Note that there are currently no approved treatments that target any of these small cell lung cancer mutations.)6

Treatment options for small cell lung cancer

There are a number of treatment options for small cell lung cancer. Which ones are used to treat a specific patient’s lung cancer will depend on the stage of the cancer and the patient’s overall health and preferences.

Treatment options fall into two categories:

  • Those that have already been approved by the FDA
  • Those that are being studied in clinical trials

What Are Currently Approved Treatment Options?

Approved treatment options for small cell lung cancer include:

  • Surgery
  • Radiation therapy
  • Chemotherapy
  • Immunotherapy

In addition, several new types of treatment are being studied for small cell lung cancer. These are available through clinical trials.

Note that a patient’s age alone does not predict whether or not that patient will benefit from treatment and should not be the only factor when deciding what treatment is best. Other factors, such as how fit a patient is otherwise and what other medical problems exist, also need to be considered.4

Read more about approved treatment options for small cell lung cancer by stage in the Treatment Options for Small Cell Lung Cancer by Stage section.


While surgery is a treatment option, it is not commonly performed in small cell lung cancer patients. There is little evidence that surgery is effective except in those patients whose cancer is very limited. When surgery is done, it is typically accompanied by adjuvant chemotherapy or a combination of chemotherapy and radiation therapy.5,7,8

Read more about different surgical options and what to expect after surgery in the Treatment Options: Surgery section.

Radiation Therapy

Radiation therapy is a type of cancer treatment that uses high-powered energy beams to kill cancer cells. Depending on the individual patient’s situation, radiation therapy may be used when trying to cure cancer, control cancer growth, or relieve symptoms caused by the tumor, such as pain.

The type of radiation therapy most often used for treating small cell lung cancer is external beam radiation therapy (EBRT).

Small cell lung cancer responds well to radiation therapy. This is usually given in combination with chemotherapy for limited-stage small cell lung cancer during the first months of chemotherapy treatment. Radiation to the brain among patients whose cancer has shrunk after treatment may also be used. In this case, use of radiation is recommended because it reduces the risk of the cancer spreading to the brain. This is known as prophylactic cranial irradiation. Radiation therapy may also be used as a palliativeCare given to improve the quality of life of patients who have a serious or life-threatening disease treatment for extensive or recurrentLung cancer that has come back after a period of time during which the cancer could not be detected disease.5,7,8

Read more about radiation therapy, including how it works, how and when it is given, the different kinds, and common side effects, in the Treatment Options:  Radiation Therapy section.


Chemotherapy is a systemic treatment that works by targeting and killing the rapidly growing cancer cells. It is the primary treatment for small cell lung cancer. Small cell lung cancer patients tend to have a good initial response to chemotherapy. The most common treatment for patients with both limited-stage and extensive-stage small cell lung cancer is a combination therapy. This includes a platinum-based drug, such as carboplatin or cisplatin, along with another chemotherapy drug, most often etoposide but also irinotecan.5,7,8

As mentioned above, radiation therapy is typically given together with chemotherapy for limited-stage small cell lung cancer. Combination chemotherapy may be used alone if a patient cannot tolerate radiation therapy. Radiation therapy may be given after chemotherapy if a patient cannot tolerate combination chemoradiation.9

Read more about chemotherapy, including how it works, how and when it is given, and possible side effects and how to manage them, in the Treatment Options: Chemotherapy section.


Immunotherapy is a type of therapy that harnesses and increases the natural ability of the patient's immune system to fight cancer. Instead of trying to stop or kill the person's cancer cells directly, as most other cancer treatments do, immunotherapy trains the person's own natual immune system to recognize cancer cells and selectively target and kill them.10

The US Food and Drug Administration (FDA) has approved two immunotherapy drugs for the treatment of small cell lung cancer:

  • Atezolizumab (Tecentriq®): approved in combination with carboplatin (Paraplatin®) and etoposide (Etopophos®) for the first-line treatment of adult patients with extensive-stage small cell lung cancer11
  • Nivolumab (Opdivo®): approved for the treatment of patients with metastatic (extensive-stage) small cell lung cancer with progression after platinum-based chemotherapy and at least one other line of therapy.12

Read more about immunotherapy, including how it works, how and when it is given, and possible side effects and how to manage them, in the Treatment Options: Immunotherapy section.

What clinical trial treatment options are available?

In addition to the approved treatments described above, doctors are testing several new types of treatment in clinical trials for people with small cell lung cancer.  The following describe some, but by no means all, of the clinical trials available for people with small cell lung cancer.

Targeted Therapy

Different types of targeted treatments are being tested in clinical trials for people with small cell lung cancer:13

  • PARP inhibitors block a protein called PARP that small cell lung cancer uses to protect itself from chemotherapy. These drugs, including veliparib and talazoparib, have shown promising results in combination with chemotherapy.14
  • Notch inhibitors block the Notch pathway that is active in SCLC. Drugs such as RovaT that target this pathway are also being tested in clinical trials. Early results suggest that RovaT is effective in small cell lung cancer patients whose cancer produces a protein called DLL3.15


Three main types of immunotherapy are now being studied in clinical trials for people with all stages of small cell lung cancer:13

  • Immune checkpoint inhibitorsAgents that target the pathways tumor cells use to evade recognition and destruction by the immune system
  • CAR-T cells: T-cells, a special type of immune cell, are removed from a patient’s body, taught to recognize the small cell lung cancer, and put back into the patient
  • Antibodies against a protein called Fuc-GM1 that is found in small cell lung cancer in high amounts

Managing symptoms and side effects

As already noted, lung cancer treatments can cause side effects. Some cancer therapy side effects are temporary, while others can be more long-term. When you start a new treatment, you should discuss with your doctor which potential side effects to expect, what can be done to manage them, and which side effects are serious and need to be reported immediately. Often, drugs can be prescribed to help reduce many of these side effects.  

In addition to the side effects of lung cancer treatment, lung cancer itself can result in a number of symptoms. Read more about the symptoms of lung cancer.

Note: It’s important to let your doctor or nurse know if you are experiencing any problems while on treatment, so they can sort out whether the problems are related to treatment or not.

Tips for managing specific symptoms and side effects related to treatment can be found in the For Supporters & Advocates section of the website, along with other practical and supportive resources for patients/survivors and caregivers.

To help reduce the severity and duration of most side effects and alleviate the cancer’s symptoms, you may want to request palliative care, also called “supportive care” or “symptom management.” There is sometimes confusion about the difference between palliative care and hospice care. Hospice care is a form of palliative care given only to patients whose life expectancy is six months or less. On the other hand, palliative care in general is an extra layer of support than can be initiated alongside other standard medical care. In fact, scientific evidence is starting to emerge that shows that palliative care may actually help patients live longer.

Read more about how palliative care can improve quality of life from the time of diagnosis.

Your healthcare team

There are a number of doctors and other medical professionals who diagnose and treat people with lung cancer. Together, they make up the comprehensive medical or healthcare team that a patient sees over the course of his or her care. Your healthcare team can describe your treatment options, the expected results of each option, and the possible side effects. You and your healthcare team can work together to develop a treatment plan.

Read more about what each member of your healthcare team does.

Updated August 20, 2018


  1. Wistuba I, Brambilla E, Noguchi M. Chapter 17: Classic Anatomic Pathology and Lung Cancer. In: Pass HI, Ball D, Scagliotti GV, eds. IASLC Thoracic Oncology, Second Edition. Philadelphia, PA: Elsevier; 2018: 143-163. Accessed December 12, 2017.
  2. Lung Cancer — Small Cell: Risk Factors and Prevention. Cancer.Net website. Updated October 206. Accessed December 12, 2017.
  3. Oser M, Niederst M, Sequist L, Engelman J. Transformation from non-small cell lung cancer to small-cell lung cancer: molecular drivers and cells of origin. Lancet Oncol. 2015 Apr: 16(4): e165-e172. doi: 10.1016/S1470-2045(14)71180-5. Accessed December 12, 2017.
  4. Lung Cancer — Small Cell: Stages. Cancer.Net website. Approved October 2016. Accessed December 12, 2017.
  5. Small Cell Lung Cancer Treatment-Health Professional Version (PDQ®). National Cancer Institute website.  Updated January 20, 2017. Accessed November 27, 2017.
  6. Peifer, M, et al. Integrative genome analyses identify key somatic driver mutations of small-cell lung cancer. Nature Genetics, October 2012. Vol 44: Number 10: 1104-1112. doi: 10.1038/ng.2396. Accessed November 29, 2017.
  7. Rudin, et al. Treatment of Small-Cell Lung Cancer: American Society of Clinical Oncology Endorsement of the American College of Chest Physicians Guide. Journal of Clinical Oncology, 2015. Vol 33: Number 34: 4101-4106l. doi: 10.1200/JCO:205.63.7918. Accessed November 29, 2017.
  8. Lung Cancer – Small Cell: Treatment Options. American Society of Clinical Oncology website.  Updated October 2016. Accessed November 29, 2017.
  9. NCCN Clinical Practice Guidelines to Oncology (NCCN Guidelines®): Small Cell Lung Cancer. Version 1.2018-September 18, 2017. The National Comprehensive Cancer Network, Inc. Accessed December 20, 2017.
  10. Biological Therapies for Cancer. National Cancer Institute website. Revised April 26, 2018. Accessed August 20, 2018.
  11.   FDA approves atezolizumab fo extensive-stage small cell lung cancer. US FDA website. Posted March 18, 2019. Accessed March 19, 2019.
  12. FDA grants nivolumab accelerated approval for third-line treatment of metastatic small cell lung cancer. US FDA website. Posted August 16, 2018. Accessed August 20, 2018.
  13. US National Institutes of Health website. Accessed November 27, 2017.
  14. Bunn Jr PA, et al. Small Cell Lung Cancer: Can recent advances in biology and molecular biology be translated into improved outcomes? J Thoracic Oncol, 2016 Apr; 11(4): 453-474. . doi: 10.1016/j.jtho.2016.01.012. Accessed November 27, 2017.
  15. Stricker, A. Rovalpituzumab Tesirine Active and Safe in Small Cell Lung Cancer. OncLive website. Posted February 13, 2017. Accessed December 20, 2017.