Lung Cancer Staging

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 diagnostic tests 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 decide what kind of treatment is best and can help predict a patient’s prognosis. There are different stage descriptions for different types of cancer.

The stage of both small cell and non-small cell lung cancer is described by a number, zero (0) through four (Roman numerals I through IV are used). One way to determine the staging of lung cancer is to find out whether the cancer can be completely removed by a surgeon. To completely remove the lung cancer, the surgeon must remove the cancer along with the surrounding, normal lung tissue. Small cell lung cancer is also sometimes described as limited-stage or extensive-stage, which are less specific descriptions.

Note: You may also hear about the TNM classification, because the stages below have been developed based on a combination of:

T:  The size of the primary tumor
N:  Whether and how regional lymph nodes are affected by the cancer
M:  Whether there is distant metastasis

The stage of lung cancer is described by a number, zero through 4 (Roman numerals I through IV are usually used).

Stage 0

This is called in situ disease, meaning the cancer is “in place” and has not invaded nearby tissues and spread outside the lung.

Lung cancer: stage 0

Stage I

A stage one (I) lung cancer is a small tumor that has not spread to any lymph nodes, making it possible for a surgeon to completely remove it if the patient is healthy enough. Stage I is divided into two substages: stage IA and stage IB, based on the size of the tumor. Smaller tumors, such as those less than 3 centimeters (cm) wide, are stage IA, and slightly larger ones (more than 3 cm but less than 5 cm wide) are stage IB.

Lung cancer: stage Ia

Lung cancer: stage Ib

Stage II

Stage two (II) lung cancer is divided into two substages: stage IIA and stage IIB. A stage IIA lung cancer describes a small tumor (less than 5 cm wide) that has spread to the nearby lymph nodes, or a slightly larger tumor (larger than 5 cm but less than 7 cm wide) that has not spread to the nearby lymph nodes. (Click on the image to see it larger.)

Lung cancer: stage IIa

Stage IIB lung cancer describes a slightly larger tumor (larger than 5 cm but less than 7 cm wide) that has spread to the lymph nodes or a larger tumor (more than 7 cm wide) that may or may not have invaded nearby structures in the lung but has not spread to the lymph nodes. (Click on the image to see it larger.)

Lung cancer: stage IIb

Sometimes stage II tumors can be removed with surgery, and other times other treatments are needed.

Stage III

Stage three (III) lung cancers are classified as either stage IIIA or stage IIIB. For many stage IIIA cancers and nearly all stage IIIB cancers, the tumor is difficult, and sometimes impossible, to remove through surgery alone. For example, the lung cancer may have spread to the lymph nodes located in the center of the chest, which is outside the lung. Or the tumor may have invaded nearby structures in the lung. Patients with stage III cancers will usually need a combination of at least two treatments, such as surgery, chemotherapy , or radiation. (Click on the images to see them larger.)

Lung cancer: stage IIIa

Lung cancer: stage IIIb

Stage IV

Stage four (IV) means the lung cancer has spread to any or all of the following:

  • The opposite lung
  • The fluid surrounding the lung or the heart
  • Distant parts of the body by way of the bloodstream

Once released in the blood, cancer can spread anywhere in the body, but it is more likely to spread to the brain, bones, liver, and adrenal glands. It is classified as stage IVA when the cancer has spread within the chest and IVB when it has spread outside of the chest.

Lung cancer: stage IV

In general, surgery is not successful for stage IV lung cancers. Lung cancer can also be impossible to remove if it has spread to the lymph nodes above the collarbone, or if the cancer has grown into vital structures within the chest, such as the heart, large blood vessels, or the main breathing tubes leading to the lungs. The doctor will recommend other treatment options.


Recurrent lung cancer is lung cancer that has come back after treatment. If there is a recurrence, the cancer may need to be staged again (called restaging) using the system above. Usually, patients with recurrent cancer are treated like patients with stage IV cancer.


The type and stage of lung cancer and the patient’s overall health influence prognosis. Although lung cancer is treatable at any stage, only certain stages of lung cancer can be cured.

Doctors measure a patient’s general strength and health by using an index known as performance status. Patients who are strong enough to go about their daily activities without assistance and work outside the home can safely receive chemotherapy, radiation therapy, and/or surgery. Treatment may not be as effective for patients with bone or liver metastases from lung cancer, excessive weight loss, ongoing cigarette use, or pre-existing medical conditions, such as heart disease or emphysema.

It is important to note that a patient’s age has never been useful in predicting whether that patient will benefit from treatment. The average age of patients with lung cancer in the United States is 71. A patient’s age should never be used as the only reason for deciding what treatment is best, especially for older patients who are otherwise physically fit and have no medical problems besides lung cancer.

Information about the cancer’s stage will help the doctor recommend a treatment plan. 

Updated February 3, 2016.

Text used with permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original and primary source for this information is the AJCC Cancer Staging Manual, Seventh Edition (2010) published by Springer Science+Business Media. Any citation or quotation of this material must be credited to the AJCC as its primary source. The inclusion of this information herein does not authorize any reuse or further distribution without the expressed, written permission of Springer, on behalf of the AJCC.