The short answer
The two main types of lung cancer are non-small cell lung cancer, which is the most common, and small cell lung cancer, which tends to grow and spread faster. The type guides treatment.
The two main types are non-small cell and small cell lung cancer.
Non-small cell lung cancer (NSCLC) is the most common, about 80% to 85% of cases.
Small cell lung cancer (SCLC) tends to grow and spread more quickly.
The two types are treated differently, so the type matters.
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The full explanation.
The simple version
Lung cancer is grouped into two main types. This is based on how the cancer cells look under a microscope. Knowing the type matters, because the two are treated quite differently.
The two main types
Lung cancer falls into two groups:
- Non-small cell lung cancer, or NSCLC — the most common type. It makes up about 80% to 85% of all lung cancers.
- Small cell lung cancer, or SCLC — less common, at about 10% to 15% of cases. It tends to grow and spread faster.
Non-small cell lung cancer in more detail
NSCLC itself has several subtypes. Adenocarcinoma is the most common subtype overall. It is also the type most often found in people who have never smoked, as well as in women and younger patients. Squamous cell carcinoma and large cell carcinoma are the other main subtypes. All three share similar general treatment approaches. But the specific drugs used can differ based on the tumor's genetic features.
Small cell lung cancer in more detail
SCLC is strongly linked to smoking, more so than most NSCLC subtypes. It tends to grow quickly. It has often spread beyond the lungs by the time it is diagnosed. Despite this, it usually responds well at first to chemotherapy and radiation. The challenge is that it commonly returns after this initial response. This shapes how doctors plan long-term treatment and follow-up.
The type of lung cancer shapes the whole treatment approach.
Why the type matters so much
NSCLC and SCLC are treated using different playbooks. SCLC responds well to chemotherapy and radiation. Those remain the backbone of treatment for most people. NSCLC treatment draws on a wider range of tools. These include surgery, radiation, targeted therapy, and immunotherapy. Doctors choose based on the cancer's stage and specific features.
Biomarker testing for non-small cell lung cancer
For NSCLC, doctors often test the tumor's genes and proteins. This is called biomarker testing. It can reveal specific changes, such as in the EGFR or ALK genes, that targeted drugs are built to attack. It can also reveal how much of a marker called PD-L1 the tumor carries. This helps predict whether immunotherapy is likely to help. Testing matches a specific drug to a specific tumor, instead of a one-size-fits-all approach.
More biomarkers than just EGFR and ALK
Doctors now test for several other gene changes too. Each one has a matching targeted drug. KRAS is treated with sotorasib. MET is treated with capmatinib. RET is treated with selpercatinib or pralsetinib. BRAF is treated with dabrafenib combinations. ROS1 is treated with entrectinib. NTRK is treated with larotrectinib. Not every tumor has one of these changes. Testing usually happens on tissue from the original biopsy. Sometimes a blood test is added too.
What to ask your team
Ask which type of lung cancer you have, and which subtype if it is non-small cell. Ask whether your tumor has been tested for biomarkers like EGFR, ALK, or PD-L1. Ask how the type affects your treatment options. Ask what the type means for your outlook.
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Words to know
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Common questions
What are the two main types?
Non-small cell lung cancer (NSCLC), the most common, and small cell lung cancer (SCLC), which is less common but tends to grow and spread faster.
How common is each?
About 80% to 85% of lung cancers are non-small cell. About 10% to 15% are small cell, which is strongly linked to smoking.
Why does the type matter?
The two types behave differently and are treated differently. Small cell lung cancer often responds to chemotherapy and radiation, while non-small cell may be treated with surgery, radiation, targeted therapy, or immunotherapy.
What is biomarker testing?
For non-small cell lung cancer, testing the tumor's genes can reveal changes that targeted therapies or immunotherapy can address, helping match treatment to the cancer.
Questions to ask your doctor
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Last updated: 2026-08-05Next planned review: 2027-07-07
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How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes. We do not employ clinicians and do not intend to — our work is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and checked line by line against the sources listed on it. That confirms the sources support what the page says. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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