Lung Cancer Staging
When lung cancer is diagnosed, the pathologist will assign a type (non-small cell lung cancer or small cell lung cancer) and a stage to the cancer. The stage is a formal classification that signifies the extent of the cancer and will determine the type of treatment your oncologist recommends. It is important to note that staging is used solely to determine the most appropriate treatment and does not indicate prognosis.
A lower stage number signifies a less advanced cancer. For example, a stage I cancer is an early stage cancer and most likely will not have spread from its place of origin. A stage IV cancer indicates an advanced stage cancer and may appear in the lung or other areas of the body (metastasis).
Lung cancers are divided into two types, non-small cell lung cancer and small cell lung cancer, depending on their cellular characteristics. The staging is different for the two types. Generally, the stage number assigned to the cancer includes characteristics for the tumor (its size, if it has spread), the lymph nodes (if the tumor has spread to them, and to which ones), and if the tumor has metastasized to distant organs. You may see this referred to as the TNM system, for Tumor, Nodes, and Metastases. The American Society of Clinical Oncology explains the system of staging and provides illustrations.
Prognosis
It is important to remember that there are treatments available for lung cancer, no matter what stage the cancer is. Treatment decisions will vary based upon the status of the individual patient and may also be influenced by the patient's strength, general health, co-existing illnesses and ability to tolerate certain treatments.
Staging of non-small cell lung cancer: The overall staging for NSCLC uses I through IV, with I being the earliest stage and IV being the latest. Evaluation of the tumor, lymph nodes, and metastases are included in the overall stage.
- Stage I: The earliest stage of lung cancer. The tumor is found only in one lung and has not spread to any lymph nodes.
- Stage II: The tumor has spread to lymph nodes that are contained within the surrounding lung.
- Stage IIIa: The tumor has spread to the lymph nodes outside of the lung, to those the tracheal area, including the chest wall and diaphragm on the same side as the cancer started.
- Stage IIIb: The tumor has spread to the lymph nodes on the opposite lung or in the neck.
- Stage IV: The tumor has spread to other parts of the lungs or distantly throughout the body.
Staging of small cell lung cancer: Small cell lung cancer is classified as either limited stage or extensive stage.
- Limited stage: the tumor is found in one lung and in nearby lymph nodes.
- Extensive: the tumor has spread beyond one lung or to other organs.