The Stages of Lung Cancer

Once lung cancer is diagnosed, an important next step is determining the stage of the cancer. Staging describes the extent or severity of a person’s cancer, which helps doctors determine the best course of treatment and a prognosis. Below is an overview of the stages of non-small cell lung cancer according to the National Cancer Institute:

Stage 0 (carcinoma in situ): Abnormal cells are found in the lining of the airways. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.

Stage I: Cancer has formed. Stage I is divided into stages IA and IB:

  • Stage IA: The tumor is in the lung only and is 3 centimeters or smaller.
  • Stage IB: Cancer has not spread to the lymph nodes and the tumor meets certain size criteria and as spread to the bronchus or innermost layer of the membrane that covers the lung.

Stage II: The cancer has spread. This stage is divided into stages IIA and IIB.

  • Stage IIA: Cancer has spread to lymph nodes on the same side of the chest as the tumor. The lymph nodes with cancer are within the lung or near the bronchus.
  • Stage IIB: Cancer has spread to lymph nodes above the collarbone or to lymph nodes on the opposite side of the chest as the tumor.

Stage III: Cancer has spread to lymph nodes on the same side of the chest as the tumor. The lymph nodes with cancer are near the sternum (chest bone) or where the bronchus enters the lung.

Stage IV: The tumor may be any size and cancer may have spread to lymph nodes and/or other parts of the body.

For more details on each stage, visit the National Cancer Institute.

This is not intended as medical advice to replace the expertise and judgment of your health care team. It is intended to help you and your family make informed decisions, together with your doctor.