Lung cancers are designated by stages to indicate how advanced the cancer is.
Non-Small Cell Lung Cancer
Occult: Cancer cells are found in mucus coughed up from the lungs, but no tumor can be seen on imaging tests. There is either not yet a tumor in the lungs or it is too small to see.
Stage 0: Abnormal cells that can lead to cancer are found in the lining of the airways. This stage is also called carcinoma in situ.
Stage I: Cancer has infiltrated the underlying lung tissue but hasn’t spread to the lymph nodes.
Stage II: Lung cancer has spread to the lymph nodes closest to the primary tumor but not to more distant lymph nodes.
Stage IIIA: Cancer has spread from the lungs to lymph nodes in the center of the chest.
Stage IIIB: Cancer has spread to other areas in the chest, such as the heart, blood vessels, trachea, or esophagus. Or, it may have spread to lymph nodes in the collarbone or to tissue that covers the lungs.
Stage IV: Cancer has spread outside the chest to other organs or parts of the body, such as the brain, the liver, or the bones.
Small Cell Lung Cancer
Small cell lung cancer is divided into two stages.
Limited: The cancer is confined to one lung and its nearby lymph nodes.
Extensive: The cancer has spread beyond one lung and may have invaded both lungs, lymph nodes far away from the original tumor, or other organs, such as the brain or liver.