After lung cancer has been diagnosed, tests are done to find out if cancer cells have spread within the lungs or to other parts of the body. This process is called staging. Knowing the stage of cancer is important for planning treatment. Dr. Mansfield, can you tell us more about the stages of lung cancer?
Absolutely, Dr. Green. Non-small cell lung cancer and small cell lung cancer are staged differently, but in both types, the cancer can spread in three ways:
- Through the tissue into nearby areas
- Through the lymph system to other parts of the body, and
- Through the blood to other parts of the body
The stages for non-small cell lung cancer include:
- Occult, or hidden, stage, in which cancer cannot be seen by imaging or bronchoscopy, but can be detected in sputum or in cell samples taken from inside the bronchi.
- Stage 0, also called carcinoma in situ, in which abnormal cells are found in the lining of the bronchi. These abnormal cells may become cancer and spread into nearby tissue.
- Stage I, which is subdivided into IA and IB. In these stages, there is a small tumor in the lung, and cancer has not spread to the lymph nodes.
- Stage II, which is also subdivided into IIA and IIB. In these stages, cancer has either spread to lymph nodes on the same side of the chest as the primary tumor, or the primary tumor has grown larger than in Stage I.
- Stage IIIA, in which cancer has spread to the lymph nodes on the same side of the chest as the tumor and has spread to nearby organs.
- Stage IIIB, in which cancer has spread to the opposite side of the chest as the tumor or to the lymph nodes above the collarbone, and may have spread to nearby organs. (and)
- Stage IV, in which cancer has spread to more distant parts of the body, such as the brain, liver, adrenal glands, kidneys, or bones.
Small cell lung cancer can be limited-stage or extensive-stage. Limited-stage small cell lung cancer means the cancer is in the lung where it started and may have spread to the area between the lungs or to the lymph nodes above the collarbone on the same side. In extensive-stage small cell lung cancer, cancer has spread beyond these areas to other places in the body.