A Guide to Types of Lung Cancer

Medically Reviewed By Adithya Cattamanchi, M.D.

Lung cancer starts inside the lung from different types of cells. The main ones are small cells and non-small cells. It is important to know whether the cancer is small cell lung cancer (SCLC), non-small cell lung cancer (NSCLC), or another type. The cells of each type have unique properties, and doctors use this information to guide treatment and evaluate the outlook.

This article is an overview of lung cancer types and causes. It will also discuss stages and treatment.

What is lung cancer?

white ribbon
Vera Lair/Stocksy United

Lung cancer is cancer that starts in lung cells. Lung cancer can start in the cells lining the airways — the bronchial tubes. These tubes branch into smaller and smaller tubes known as bronchioles. Alveoli are tiny sacs at the end of bronchioles. Cancer can also start in these areas.

Cancer cells continue to grow and divide when regular cells would not. Cancer cells can form solid tumors and spread to other parts of the body.

Lung cancer is the third most common cancer in the United States, according to the Centers for Disease Control and Prevention (CDC) Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source .

Types of lung cancer

The two main types of lung cancer are NSCLC and SCLC.

Your medical team will diagnose the type of lung cancer by collecting a sample and looking at the cells under a microscope.

Learn about diagnostic tests for lung cancer.

Non-small cell lung cancer

NSCLC is the most common type of lung cancer — accounting for 80–85% Trusted Source American Cancer Society Highly respected international organization Go to source of lung cancers, per the American Cancer Society (ACS). Several subtypes end with the term “carcinoma.” This is cancer that begins on the skin or in epithelial tissues that line or cover internal organs, such as the airways and lung tissue.

Subtypes include:

  • Adenocarcinoma: This is the most common subtype. It starts from cells that line the alveoli and secrete mucus. Doctors tend to find it in the outer parts of the lung. It is more likely than other subtypes and SCLC to be found before it has spread. Smoking is the most common cause. However, adenocarcinoma is the most common form of lung cancer in people who have never smoked, according to the ACS.
  • Squamous cell carcinoma: This subtype starts in squamous cells that line the airways. Smoking is the main cause of squamous cell lung cancer. Doctors tend to find this cancer in the center of the lungs.
  • Large cell (undifferentiated) carcinoma: This subtype can develop from large cells in the airways. It grows and spreads quickly, so doctors may treat it differently than other NSCLC subtypes. Large cell carcinoma includes large cell neuroendocrine carcinoma, which is similar to SCLC.

Stages and treatment

NSCLC treatment depends on the stage and certain biological markers in the cancer cells. Clinicians use imaging tests and other tests to gather this information.

There are five stages of NSCLC, from 0–4. The higher the number, the more advanced the cancer.

Stage 1 and 2 are what clinicians may describe as early stage cancers, per the National Comprehensive Cancer Network (NCCN). Stage 3 is locally advanced, which means the cancer has spread into the lung tissue and may have spread to nearby lymph nodes. Stage 4 is advanced lung cancer. Another name for it is metastatic lung cancer.

Sometimes, early stage cancers are cured. Locally advanced cancers are rarely cured, says the NCCN. There is no cure for metastatic lung cancer.

However, all lung cancers can be treated to slow or stop cancer growth, ease symptoms, and extend life.

The standard treatment Trusted Source American Cancer Society Highly respected international organization Go to source for stage 1 NSCLC is surgery. Your doctor may also recommend chemotherapy and radiation therapy. Treatment for stages 2–4 NSCLC may include a combination of:

Learn more about NSCLC treatment.

Small cell lung cancer

SCLC accounts for 10–15% Trusted Source American Cancer Society Highly respected international organization Go to source of all lung cancers, according to the ACS. SCLC is also a carcinoma, but it starts in neuroendocrine cells that line the inner airways of the lungs. These cells normally help heal damage to other cells that line the airway. They have features of nerve cells and hormone-producing endocrine cells.

SCLC grows faster and spreads earlier than NSCLC. Per the ACS, in about 70% of people who receive a diagnosis of SCLC, the cancer has already spread outside the lung.

Smoking is the main cause of SCLC.

Stages and treatment

Doctors most often use a two-stage system for SCLC:

  • Limited stage: These cancers are on one side of the chest. Radiation therapy is a common treatment intended to cure the cancer, explains the NCCN. Chemotherapy, immunotherapy, and surgery may be options as well.
  • Extensive stage: These cancers have spread across to the other lung or distant parts of the body. Doctors may treat this stage with chemotherapy or immunotherapy, or both. There are some uses for radiation and surgery as well.

Learn more about SCLC staging and treatment.

Lung carcinoid tumor

Lung carcinoid tumors begin in neuroendocrine cells. They account for less than 5% Trusted Source American Cancer Society Highly respected international organization Go to source of lung cancers. Most lung carcinoid tumors grow slowly and rarely spread Trusted Source American Cancer Society Highly respected international organization Go to source beyond the lungs. This makes treatment more straightforward.

Staging and treatment

Most doctors use only two stages to describe lung carcinoid tumors:

  • Resectable stage: Surgery may be done to remove the cancer at this stage and may cure it Trusted Source American Cancer Society Highly respected international organization Go to source .
  • Unresectable stage: Surgery cannot completely remove these cancers. Or, you may not be healthy enough for surgery. Radiation therapy is the usual treatment. Chemotherapy is not as useful for carcinoid tumors because they grow slowly. It is more effective for tumors that grow quickly.

Other types of cancer affecting the lungs

Other tumors Trusted Source American Cancer Society Highly respected international organization Go to source involving the lungs include less common types of lung cancer and cancers that start in another area of the body and spread to the lung.

Other lung tumors

These include:

  • primary lung lymphoma
  • sarcoma, cancer that starts in bones and soft tissues like muscles and blood vessels
  • benign tumors, which are not cancerous

Lung metastases: Cancers that spread to the lungs

Nearly any type of cancer can spread — metastasize — to the lung. Per the ACS, the main ones Trusted Source American Cancer Society Highly respected international organization Go to source include:

When cancer metastasizes to the lung, it is still the primary cancer. For example, breast cancer that spreads to the lungs is not lung cancer. It is breast cancer.

Frequently asked questions

Adithya Cattamanchi, M.D., reviewed the following questions.

What is the most serious type of lung cancer?

Clinicians consider SCLC the most aggressive type of lung cancer because it grows and spreads faster Trusted Source American Cancer Society Highly respected international organization Go to source than NSCLC. It is also likely to return after treatment.

Does lung cancer spread quickly?

Yes, lung cancer spreads quickly. A 2021 study in the Journal of Thoracic Oncology estimates that most lung cancers spread approximately 2.74 years before clinical detection, based on computer modeling. Tumors may spread to the lymph nodes earlier.

Which is worse: Right or left lung cancer?

For NSCLC, there does not appear to be a significant difference in overall survival or cancer-specific survival for cancer in the left versus right lung, according to a statistical analysis Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source of a large cohort of patients from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute.

What organs does lung cancer spread to?

Lung cancer commonly spreads to the liver, adrenal glands, bone, brain, and other lung.

Summary

NSCLC is the most common type of lung cancer, followed by SCLC and lung carcinoid tumors. Knowing the type and stage of the cancer is important for treatment decisions. The outlook for a cure is more favorable for NSCLC and lung carcinoid tumors than SCLC. Although, in general, it is difficult to cure lung cancer.

To learn more, consider these articles:

Was this helpful?
76
  1. How is lung cancer diagnosed and treated? (2021). http://www.cdc.gov/cancer/lung/basic_info/diagnosis_treatment.htm
  2. Jia, B., et al. (2019). Survival comparison of right and left side non‐small cell lung cancer in stage I–IIIA patients: A Surveillance Epidemiology and End Results (SEER) analysis. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6397910/
  3. Lung cancer. (n.d.). http://www.cancer.org/cancer/lungcancer/
  4. Lung cancer statistics. (2022). https://www.cdc.gov/cancer/lung/statistics/
  5. Lung carcinoid tumor stages. (2018). https://www.cancer.org/cancer/lung-carcinoid-tumor/detection-diagnosis-staging/staging.html
  6. Lung metastases. (2020). https://www.cancer.org/treatment/understanding-your-diagnosis/advanced-cancer/lung-metastases.html
  7. Metastatic cancer: When cancer spreads. (2020). https://www.cancer.gov/types/metastatic-cancer
  8. Non-small cell lung cancer — early and locally advanced. (2022). https://www.nccn.org/patients/guidelines/content/PDF/lung-early-stage-patient.pdf
  9. Pina-Oviedo, S., et al. (2015). Primary pulmonary lymphoma [Abstract]. https://journals.lww.com/anatomicpathology/Abstract/2015/11000/Primary_Pulmonary_Lymphomas.3.aspx
  10. Small cell lung cancer. (2022). https://www.nccn.org/patients/guidelines/content/PDF/SCLC-patient-guideline.pdf
  11. Tang, W. F., et al. (2020). Timing and origins of local and distant metastasis in lung cancer. https://www.jto.org/article/S1556-0864(21)01746-9/fulltext
  12. Treatment of lung carcinoid by type and extent of disease. (2018). https://www.cancer.org/cancer/lung-carcinoid-tumor/treating/by-stage.html
  13. Types of lung cancer. (2021). https://www.lung.org/lung-health-diseases/lung-disease-lookup/lung-cancer/basics/lung-cancer-types
  14. What are lung carcinoid tumors? (2018). https://www.cancer.org/cancer/lung-carcinoid-tumor/about/what-is-lung-carcinoid-tumor.html

Medical Reviewer: Adithya Cattamanchi, M.D.
Last Review Date: 2022 Sep 19
View All Lung Cancer Articles
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.