Lung Cancer Staging
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Staging is a system that describes the extent of cancer in the body. Our cancer doctors use a variety of diagnostic tests to stage lung cancer and develop the best treatment plan for you.
When lung cancer is diagnosed, your oncologist will assign a type based on the appearance of the cells under a microscope: either non-small cell lung cancer or small cell lung cancer.
Your oncologist will stage the cancer based on how the disease develops in the body, including:
- The location of the original tumor
- Tumor size and number of tumors
- Whether the cancer has spread to the lymph nodes
- Cell appearance under a microscope
- Whether the cancer has spread to other parts of the body, called metastasis
The staging system is different for the two types of lung cancer.
Small Cell Lung Cancer Staging
Small cell lung cancer is classified in one of two ways:
- Limited Stage: Cancer is 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 is staged using 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. For instance, a T1 score indicates a smaller tumor than a T2 score. The letter X means the information could not be assessed.
Once the T, N, and M scores have been assigned, an overall stage is assigned.
Stages of non-small cell lung cancer:
- Occult stage – This is the primary stage in which no tumor is visible, but cancerous cells are identified within the lung (usually in a sample of mucus).
- Stage 0 (also known as carcinoma in situ) – Cancerous cells are found only in the top layers lining the lung.
- Stage 1A – Cancer penetrates the inner tissue and resides in other tissue layers within the lung. The tumor is not larger than 1.2 inches.
- Stage 1B – The tumor measures 1.2 - 2 inches, or reaches the bronchus, or has reached the pleura, or is partially blocking the airways.
- Stage IIA – The tumor is less than 2 inches, or id in the bronchus, pleura or clogging the airways, and the cancer penetrates nearby lymph nodes; or the tumor is 2 - 2.8 inches in size and has not reached the lymph nodes.
- Stage IIB – The tumor measures 2 - 2.8 inches and has spread to nearby lymph nodes; or the tumor is larger than 2.8 inches or there is more than one tumor; or the tumor has grown into the diaphragm, pleura, chest wall, or the tissue surrounding the heart, but the cancer has not reached the lymph nodes.
- Stage IIIA – A tumor of any size has spread to lymph nodes around the carina and the mediastum; or the tumor is larger than 2.8 inches and has reached nearby lymph nodes; or the tumor has spread into nearby structures, such as the heart, esophagus or backbone, and possibly into nearby lymph nodes.
- Stage IIIB – A tumor of any size has spread to lymph nodes in the other side of the chest; or the tumor has grown into nearby structures, such as the heart, esophagus or backbone as well as nearby lymph nodes. There may be multiple tumors.
- Stage IV – A tumor of any size has spread to the other lung, to the pleura or to the fluid found in the heart; or the cancer has spread to more distant parts of the body. At this stage, the bones and brain are especially susceptible to cancerous metastases.
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