Mesothelioma is classified into various stages by the level of advancement of the disease in affecting the patient. This classification system is known as Butchart’s staging system. There are 3 separate mesothelioma stages that a patient will go through: Stage I, Stage II and Stage III. The chances of survival decrease with progression into the next stage.
The experience typical of Stage I is the beginning of initial tumor invasion. This would be classified as a local invasion where the tumor is strictly limited to the pleura and that particular area.
Stage II is a moderate level of tumor advancement. The tumor may begin to affect the pleura more heavily and begin to invade the actual lung cavity. In stages I and II it is extremely important to not assume tumor progression. A phenomena known as stage migration will often occur when the patient is not suspected to have advanced tumor complications. This actually causes the patient to migrate from the stage they are at to a more advanced stage of the disease.
Stage III is the most advanced form of MPM. At this point the tumor has spread to other areas of the body that are distant from the lung region. Organs such as the liver and kidneys are affected with cancerous tumors that create major difficulty for the patient. A skilled physician will use the diagnostic tests to determine what stage patient is at. A CAT scan is an effective tool to document the extent of the tumor and how it has affected the pleural region in regards to staging.