Doctors often rely on knowing the different stages of mesothelioma to be able to effectively treat this type of cancer. Like most other cancers, this type of cancer passes through different stages as the disease advances, these different stages have significant bearing on the type of treatment that will be prescribed and on the most likely outcome of the disease.

The various mesothelioma stages generally indicate how far the disease has progressed beyond its original point of origin. Localized mesothelioma is diagnosed when the cancer has not spread beyond the membrane (most often the lining of the lungs) in which it originated. If the cancer cells have spread beyond this lining to invade the lungs, chest wall cavity or other body organs it is considered an advanced mesothelioma stage, which is much more difficult to treat.

Beyond this informal localized vs. advanced classification, four distinct stages are recognized by each of the two most widely used mesothelioma staging systems. One system, the TNM staging system, is used most often in progressive cancer treatment centers and is recognized by the American Cancer Society as the most accurate mesothelioma staging system.

The other, the Butchart Staging System, is the most common system for staging cancer in general.

Butchart Mesothelioma Stages

The Butchart system classifies mesothelioma cancer into four different stages depending on the stage of the main tumor mass.

• Stage I - Cancer is only seen in one side of the chest lining, or pleura

• Stage II - The mesothelioma has spread to any one of the chest wall, esophagus or heart or the lymph nodes of the chest

• Stage III - The cancer has invaded the diaphragm and the lining of the abdominal cavity (peritoneal cancer) or has spread to additional lymph nodes in the body

• Stage IV - Mesothelioma has spread to several major organs The Butchart staging system has been replaced largely by the TNM system for classifying mesothelioma cancer stages.

TNM Staging System

TNM stands for Tumor, Nodes and Metastasis; three keys to determining how advanced mesothelioma cancer is using this system. T stands for the extent of the tumor, N for how advanced the disease is in the lymph nodes and M for the extent of spread of the cancer into other organs.

• Stage I - Mesothelioma is restricted to the pleura of the chest and has not spread to other areas.

• Stage II - The cancer has spread to the pleural lining and to the outer lining of the lung or into the lung itself.

• Stage III - In addition to the pleura, mesothelioma spreads to part of the chest cavity behind the breast bone or within the chest wall. This stage also usually includes cancer of the lymph nodes.

• Stage IV - The most advanced of the mesothelioma stages, when cancer has spread to major organs or the bones or brain. Metastasis refers to the generalized spreading of the cancer.

Each individual case of mesothelioma is different and these stages are not the only factors that determine the type of treatment and the prognosis of the disease. Other factors come into consideration.