Lung cancer stages
Small cell lung cancer staging
Small cell lung cancer makes up less than 20 percent of lung cancers and is typically caused by tobacco smoking. It often starts in the bronchi, then quickly grows and spreads to other parts of the body, including the lymph nodes. Small cell lung cancer stages are classified in two ways:
- Limited stage: The cancer is found in one lung, sometimes including nearby lymph nodes.
- Extensive stage: Cancer has spread to the other lung, the fluid around the lung (the pleura) or to other organs in the body.
Non-small cell lung cancer staging
Non-small cell lung cancer staging uses the TNM system:
- Tumor (T) describes the size of the original tumor.
- Lymph node (N) indicates whether the cancer is present in the lymph nodes.
- Metastasis (M) refers to whether cancer has spread to other parts of the body, usually the liver, bones or brain.
A number (0-4) or the letter X is assigned to each factor. A higher number indicates increasing severity. The letter X means the information could not be assessed. For instance, a T1 score indicates a smaller tumor than a T2 score. Once the T, N and M scores have been assigned, an overall stage is assigned.
Stages of non-small cell lung cancer: