Stages of Mesothelioma

Staging allows doctors to classify the severity and spread of cancer after diagnosis. The only mesothelioma that has a formal staging system is malignant pleural mesothelioma. This categorizes the disease into four stages, with stage I being the mildest and stage IV being the most severe.

In stage I pleural mesothelioma, the cancer has not spread beyond the mesothelial lining. Aggressive treatments are typically used, and life expectancy is 21 months or more. In stage II, the mesothelioma has spread to nearby areas such as the diaphragm or lungs. Aggressive treatments may still be used, but life expectancy is 19 months or less. In stage III, cancer has affected organs, tissues, and lymph nodes, and there are limited treatment possibilities. Life expectancy drops to 16 months or less. In stage IV, the cancer has spread extensively. There are limited options for treatment, and life expectancy is a year or less.

When assessing prognosis, doctors also determine whether the cancer is resectable, meaning it can be removed by surgery, or unresectable, meaning that at least some of the cancer cannot be removed. Generally mesothelioma tumors may be resectable in stage I, stage II, and sometimes stage III.