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: (1) histology—what the cells look like under a microscope; and (2) biomarker profile (also called molecular profile, genomic profile, or signature profile)—the kinds of A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease found in the tissue.
Because each type of lung cancer behaves and is treated differently, it helps to have as much information as possible about a person’s individual lung cancer. To get that information, a pulmonologist or surgeon should provide samples of the tumor from a The removal of cells or tissues for examination by a pathologist to a A doctor who identifies diseases by studying cells and tissues under a microscope or with other equipment. Having a pathologist who is experienced in looking at lung cancer will provide the most accurate information.
Classification by histology
The different types of lung cancer are described histologically by the types of cells the pathologist sees under the microscope. About 85% of lung cancers are non-small cell lung cancer (NSCLC), about 15% of lung cancers are small cell lung cancer (SCLC).1,2
There are three major types of non-small cell lung cancer:
- Lung adenocarcinoma
- Squamous cell lung cancer (also called epidermoid carcinoma)
- Large cell lung cancer
More information on each of these types is available on separate pages on this website.
Other histologic types
Among the less common types of lung cancer are sarcomatoid carcinoma, salivary gland tumors, and unclassified carcinomas.2
Classification by biomarker profile
Lung cancer is a complex disease that not only is classified by cell type, but also can be divided further by mutation—the changes to the cell that allowed the cancer to grow. Each type of lung cancer may or may not have one of the mutations. So far, researchers have identified a number of different mutations, called driver mutations, that can lead to lung cancer, and they are continuing to look for more. To date, there has been the most progress in understanding adenocarcinoma driver mutations, but scientists are also learning about squamous cell and small cell driver mutations.3,4,5
Updated February 10, 2021
- What is Non-Small Cell Lung Cancer? American Cancer Society website. https://www.cancer.org/cancer/non-small-cell-lung-cancer/about/what-is-non-small-cell-lung-cancer.html. Revised October 1. 2019. Accessed February 10, 2021.
- 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; 2018:143-146. Accessed February 10, 2021.
- Hirsch FR, Suda K, Wiens J, Bunn PA Jr. New and emerging targeted treatments in advanced non-small cell lung cancer. Lancet. Sep 3 2016; 388(10048)L1012-1024. https://pubmed.ncbi.nlm.nih.gov/27598681/. Accessed February 10, 2021.
- Cancer Genome Atlas Research Network. Comprehensive genomic characterization of squamous cell lung cancer. Nature. Sep 27 2012; 489(7417): 519-525. https://www.nature.com/articles/nature11404. Accessed November 16, 2020.
Perez-Moreno P, Brambilla E, Thomas R, Soria JC. Squamous cell carcinoma of the lung: molecular subtypes and therapeutic opportunities. Clinical Cancer Research. May 1 2012; 18(9): 2443-2451. https://www.researchgate.net/profile/Pablo_Perez-Moreno/publication/221693814_Squamous_Cell_Carcinoma_of_the_Lung_Molecular_Subtypes_and_Therapeutic_O.... Accessed November 16, 2020.