Mesothelioma Prognosis: Biology of the Disease

The most important disease-specific prognostic factors for patients with mesothelioma involve the form of mesothelioma as presented and the histological subtype of the presented disease. Of the two major forms of mesothelioma, pleural mesothelioma generally presents with a worse prognosis than peritoneal mesothelioma does. The physiological reasons for this difference are not completely understood, but a major factor is the histological aspect of the cancer. Pleural mesothelioma presents about fifty percent of the time with an epitheloid histologic subtype, twenty percent of the time with sarcomatoid subtype and the remaining thirty percent is the biphasic subtype, which is a combination of the previous two subtypes. Peritoneal mesothelioma presents in the vast majority of diagnoses with the epitheloid subtype. This is significant because epitheloid mesothelioma responds more favorably to treatment than sarcomatoid mesothelioma or biphasic mesothelioma does. Thus, with the majority of peritoneal cases featuring the most treatable histological subtype, one would expect for it to have a better overall prognosis. Conversely, with only half of pleural cases involving the most treatable subtype, one would also expect a generally worse prognosis.