Recently, the TNM Staging System has been developed by the American Joint Committee on Cancer (AJCC) and has similarities to another staging system used for most other cancers. The "T" stands for tumor (the size and extent of the tumor has spread to nearby organs); "N" stands for spread to the lymph nodes, while the "M" stands for metastatic (spread to organs far away from the original tumor).
In the TNM Staging System for mesothelioma, lymph nodes, information about metastatic tumors, and combined in a process called stage grouping to set the stages described by numbers 1-4. There is a small difference between the Butchart staging system and the system is the TNM Staging.
Stage 1: Involves the pleura Mesothelioma: left or right, may also have spread to the lungs, the diaphragm on the same side, or the pericardium. For this stage still has not spread to lymph nodes.
Stage 2: Mesothelioma has spread from the pleura on one side to the nearest peribronchial or hilar lymph nodes in the lung on the same side. For this stage may have spread to the lungs, the diaphragm on the same side, or the pericardium.
Stage 3: Mesothelioma has spread to the muscles of the chest wall, ribs, heart, esophagus, or other organs as the primary tumor in the chest on the same side, without or with spread to lymph nodes or subcarinal mediastinum on the same side as the primary tumor. Subcarinal nodes are at the point where the branches of the throat to the lungs right or left. Mediastinum lymph nodes are located in the back of the sternum right in front of the heart. Mesothelioma with the same level of localized as in phase 2 which also have spread to or subcarinal lymph nodes on the same side of the mediastinum are also included in phase 3.
Stage 4: Mesothelioma has spread to the lymph nodes in the chest on the opposite side of the primary tumor, or directly extends to the lung or pleura in the opposite side, or directly extends to the organ part in the abdominal cavity or neck, or directly extends into the peritoneum. Each mesothelioma with proof of who had done the distant metastasis (spread to other organs through the bloodstream) or has spread to organs outside of the chest or abdomen are also included in this stage.