Know Your Stage

Staging Non-Small Cell Lung Cancer

Treatment decisions are based in large part on the stage, or extent, of the cancer. Non-small cell lung cancer is commonly staged using the TNM staging method. T refers to tumor size (how big the tumor is and whether it has spread in the area), N refers to lymph nodes (are any lymph nodes positive for cancer, and if so how many), and M refers to metastasis (has the cancer spread to other parts of the body).

Doctors use these criteria to assign a cancer stage:

Stage 0 Abnormal cells have been found in the inner lining of the lung. Though these cells are not yet cancer, they may become cancer. Stage 0 is also called carcinoma in situ

Stage IA The tumor is in the lung only and is 3 cm or smaller.

Stage IB One or more of the following is true: the tumor is 3-5 cm, the cancer has spread to the main bronchus of the lung, the cancer has spread to the innermost layer of the membrane that surrounds the lung, or the tumor is partially blocking the bronchus or bronchioles.

Stage IIA The tumor is 5-7 cm in size, or has spread to lymph nodes on the same side of the chest as the tumor.

Stage IIB

Cancer has spread to lymph nodes on the same side of the chest as the tumor, and one or more of the following is true:

  • The tumor is larger than 7 cm.
  • Cancer has spread to the main bronchus of the lung.
  • Cancer has spread to the innermost layer of the membrane that covers the lung
  • The tumor is partially blocking the bronchus or bronchioles.

or
Cancer has not spread to lymph nodes and one or more of the following is true:

  • Cancer has spread to the chest wall, diaphragm, the pleura between the lungs, or the membranes surrounding the heart.
  • Cancer has spread to the main bronchus of the lung but has not spread to the trachea.
  • Cancer blocks the bronchus or bronchioles and the whole lung has collapsed or become inflamed.

Stage IIIA

Cancer has spread to lymph nodes on the same side of the chest as the tumor, and:

  • The tumor may be any size.
  • Cancer may have spread to the main bronchus, the chest wall, the diaphragm, the pleura around the lungs, or the membrane around the heart, but it has not spread to the trachea.
  • Part or all of the lung may have collapsed or become inflamed.
  • Lymph nodes in the mediastinum are involved.

Stage IIIB The tumor may be any size and has spread:
  • To lymph nodes above the collarbone or on the opposite side of the chest from the tumor.
  • To any of the following: the heart, major blood vessels leading to or from the heart, the chest wall, the diaphragm, the trachea, the esophagus, the sternum, or another area within the same lobe of the lung.
Stage IV Cancer may have spread to lymph nodes, to another lobe of the lungs, to the fluid of the pleural cavity surrounding the lung, or to other parts of the body such as the brain, liver, adrenal glands, kidneys, or bone.
   

Staging Small Cell Lung Cancer

Because small cell lung cancer is often diagnosed at a more advanced state, the TNM system is generally not used. Instead, small cell lung cancer is usually staged using a two-stage system based on location of the cancer. This system divides SCLC into "limited stage" and "extensive stage."

Limited-stage: The cancer is located in only one lung and lymph nodes on the same side of the body.

Extensive-stage: The cancer has spread to the other lung and/or other regions of the body. Most small cell lung cancers are diagnosed in the extensive stage.