Mesothelioma stages are categorized in the medical community for evaluative benefit for the physician, the medical institution, participation in clinical trials, and advancements in mesothelioma treatment options. Staging systems are used to define mesothelioma stages; however, mesothelioma stages are far more descriptive for pleural mesothelioma than for peritoneal mesothelioma or pericardial mesothelioma. Mesothelioma staging systems have changed over time. As medical knowledge increases, mesothelioma staging systems advance. By sectioning a progressive disease into stages, doctors can evaluate mesothelioma treatment options that have been proven successful. By defining mesothelioma stages in a universal staging system, international mesothelioma life expectancy statistics can be gathered. When a staging system gains international acceptance, it contributes greatly to the advancement of mesothelioma treatment options. Grouping similar variables for evaluation is benefic