Stages of Lung Cancer

Stages of Lung Cancer

The following stages are used for non-small cell lung cancer:

Occult (hidden) stage

In the occult (hidden) stage, cancer cells are found in sputum (mucus coughed up from the lungs), but no tumor can be found in the lung by imaging or bronchoscopy, or the primary tumor is too small to be assessed.

Stage 0 (carcinoma in situ)

In stage 0 (carcinoma in situ), cancer is limited to the lung and is found only in a few layers of cells. It has not grown through the top lining of the lung.

Stage I

In stage I, the cancer is in the lung only, with normal tissue around the tumor. Stage I is divided into stages IA and IB, based on the size of the tumor.

Stage II

In stage II, cancer has spread to nearby lymph nodes or to the chest wall (the ribs and muscles that make up the area of the body between the neck and the abdomen), the diaphragm (the thin muscle below the lungs and heart that separates the chest from the abdomen), the mediastinal pleura (the thin membrane that covers the outside of the lungs in the area near the heart), or the parietal pericardium (the outer layer of tissue that surrounds the heart). Stage II is divided into stage IIA and stage IIB, based on the size of the tumor and whether it has spread to the lymph nodes.

Stage III

In stage III, cancer has either:

spread to the lymph nodes in the mediastinum (the middle area between the lungs that contains the heart, major blood vessels, and other structures); or

spread to the lymph nodes on the opposite side of the chest or in the lower neck.

Stage III is divided into stage IIIA (which is sometimes treated with surgery) and stage IIIB (which is rarely treated with surgery).

Stage IV

In stage IV, cancer has spread to other parts of the body or to another lobe of the lungs.