Mesothelioma Symptoms and Stages
Treatment and outlook for a patient with mesothelioma depends upon the stage, or extent, of the patient's cancer.
Mesothelioma has been categorized by three systems of stages. However, lead cancer entities like the American Cancer Society, the American Joint Committee on Cancer, and the International Mesothelioma Interest Group have endorsed one system in particular, called the TNM System. This system is outlined below.
Leading System Involves Four Stages
TNM is an acronym, where “T” represents the size of a tumor, “N” stands for a spread to the lymph nodes, and “M” refers to metastasis—whether the cancer has spread to distant organs. Each of the three categories involves four stages, which are then grouped together to determine a general stage.
Stage 1 mesothelioma involves localized cancer in either the left or right pleura lining of the chest. If the cancer has spread, it may only have reached a few small areas of the outer lining of the lung. Mesothelioma may not be found in the lymph nodes or other areas of the pleural or peritoneal cavities at this stage.
If the patient's pleural mesothelioma has spread from the pleural lining of the chest into the outer lining of the lungs, diaphragm or lungs, the cancer will be categorized as Stage II mesothelioma. However, at this stage, the cancer still has not spread to the lymph nodes or distant sites.
Once pleural mesothelioma has reached the lymph nodes of the chest on the same side as the pleural tumor, it will be considered Stage III mesothelioma. Mesothelioma will also be categorized as Stage III if the pleural mesothelioma has spread into:
• the first layer--or in a single place—within the chest wall
• the fatty part of the mediastinum (the area between the pleural cavity, containing the esophagus, trachea, and thymus)
• the outer layer of the heart
Pleural mesothelioma reaches Stage IV when the cancer has spread into:
• chest wall, muscle or ribs through the diaphragm
• organ of the mediastinum
• spine across the pleura to the opposite side of the chest from the point of origin
• through heart lining or into the heart
• the nerves leading to the arm (brachial plexus)
The cancer, at this stage, might not have reached the lymph nodes and has not spread to other areas of the body. Pleural mesothelioma may also be diagnosed as Stage IV if it has:
• spread to distant sites of the body
• moved to distant sites but has spread to the lymph nodes of the collar bone
• moved to the hilar (the depression in the surface of a lung)
• mediastinal lymph nodes on the opposite side of lung from where the cancer originated