Stages of Lung Cancer

Reviewed by: HU Medical Review Board | Last reviewed: March 2024 | Last updated: March 2024

The stage of lung cancer refers to the extent of cancer progression. This includes the location of cancer cells, the size of lung cancer nodules, and whether it has spread. Your doctor will perform imaging and other tests to determine your lung cancer stage.1

The stages are different for non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Knowing your lung cancer stage can help doctors determine the best treatment. It can also help them understand potential health outcomes. Talk to your doctor about what your lung cancer stage means for you.1

Scoring system for lung cancer stages

Three factors go into determining your lung cancer stage. This system is called the tumor, node, metastasis (TNM) system. The TNM scoring system assigns values to:1-3

  • T – Tumor size and location
  • N – Lymph node involvement
  • M – Metastasis, or spread of the cancer to other organs

Based on your TNM score, your doctor can assign a stage number. An earlier stage (lower number) refers to cancers that are generally smaller and have minimal spread. They are more likely to have better health outcomes.1-3

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This system can be used for both NSCLC and SCLC. But it is not generally as important for SCLC.3,4

Stages of NSCLC

NSCLC stages range from 0 to 4 and are often shown as Roman numerals. They are divided into substages based on the size and location of the cancer. The NSCLC stages are:1,2,5

  • Stage 0 – Early stage, with cancer only in the top lining of the lung or bronchus
  • Stage I – Cancer in deeper lung tissue but not in lymph nodes
  • Stage II – Larger tumors or cancer that has started to spread to nearby lymph nodes
  • Stage III – Even larger tumors and/or cancer that has increasingly spread to lymph nodes, potentially including the lymph nodes between the lungs
  • Stave IV – Cancer that has generally spread to other areas of the body

The process and timing of staging vary for different people with NSCLC. Doctors often stage NSCLC in 2 steps:1,2

  1. Clinical stage – Assigned by using imaging tests and biopsies before treatment
  2. Pathological or surgical stage – Assigned after surgery to remove the cancerous tissue

Many people with advanced NSCLC do not undergo surgery. So the clinical stage is most often used. But the pathological stage gives a more accurate assignment. Surgery may reveal cancer in areas not seen on imaging tests. It may also reveal that a suspected cancer was not cancerous.1

In some people, lung cancer can be diagnosed, staged, and treated all in 1 operation. If the cancer comes back after treatment, the cancer is often staged again.1

Stages of SCLC

Staging for SCLC is different. This type of cancer is often assessed as 1 of 2 stages:1,4

  • Limited stage – Cancer is in only 1 lung, with or without spread to nearby lymph nodes
  • Extensive stage – Cancer is in both lungs or has spread to distant organs

In about 2 out of 3 people with SCLC, the cancer is in the extensive stage at the time of diagnosis.4

How lung cancer staging is used

The stage of lung cancer helps doctors determine the best treatment. Earlier-stage NSCLC may be treated with surgery. A combination of treatments may be used for later-stage NSCLC.1,4

With SCLC, doctors may use treatments to try to cure a cancer in the limited stage. If the person has extensive stage SCLC, the doctor will probably use treatment to control the cancer but not cure it.1,4

The lung cancer stage also provides a general picture of expected health outcomes. Doctors can look at the experiences of other people with the same type and stage of lung cancer. This can help doctors predict likely health outcomes. But everyone with lung cancer is different. Many factors affect your response to treatment and health outcomes.1,5