Classifying and staging lung cancer
Lung cancer staging is the process of finding out if cancer is present and how far it has spread. Non-small cell lung cancer and small cell lung cancer are staged differently.
Our doctors use the TNM system to stage non-small cell lung cancer. The TNM staging system is one of the most widely used cancer-staging systems worldwide. It describes:
- Tumor (T): The size and other characteristics of the main tumor, called the primary tumor.
- Node (N): The number of lymph nodes affected by cancer cells.
- Metastasis (M): If the cancer has spread to other parts of the body.
These details help to classify the cancer into one of the following stages:
- Stage I: The cancer is in the lungs and has not spread.
- Stage II: The cancer is in the lungs and has started to spread to nearby lymph nodes.
- Stage III (locally advanced disease): The cancer is in the lungs and lymph nodes in the chest. Stage III has two subtypes:
- Stage IIIA: The cancer has spread to lymph nodes on the same side of the chest as the primary tumor.
- Stage IIIB: The cancer has spread to lymph nodes on the other side of the chest or by the collarbone.
- Stage IV (advanced disease): The cancer is in both lungs or has spread to fluid around the lungs or other parts of the body, such as the liver, bones, or brain.
The small cell lung cancer stages are broken up into two categories:
- Limited-stage small cell lung cancer: The cancer is in the lung and may have spread to an area between the lungs called the mediastinum or to lymph nodes near the collarbone.
- Extensive-stage small cell lung cancer: The cancer has spread to other areas in the body.