There are three types. Mesothelioma is a tumor of the mesothelial cells which make up the lining that surrounds and protects the heart (pericardium), lungs (pleural) and abdomen (peritoneal). Pleural mesothelioma is the most common and affects the lungs. Pleural mesotheliomas can be benign or malignant,with the cancerous type being most common. Prognosis is poor with approximately a 17-month survival from symptom onset. Peritoneal mesothelioma affects the abdomen and is the second most common of the mesotheliomas. Prognosis for peritoneal mesothelioma is worse at 10 months from symptom onset. There is a rare and benign form of peritoneal mesothelioma, seen mostly in young females. Pericardial mesothelioma affects the heart, this is the rarest of the three and prognosis is the poorest.
A good prognosis as the time of disease presentation is associated with the following:
Tissue histology of epithelial origin
Stage I disease
Age under 65 years
Performance status of 0 to 1 (minimal effect on health)
Lack of chest pain
The presence of symptoms for more than 6 months prior to diagnosis
A poor prognosis at the time of disease presentation is associated with the following:
Age >65 years
Sarcomatous or mixed tissue histology
Fever of unknown origin
Male gender
Poor performance status
Blood cell dyscrasias
The mean survival of patients with mesothelioma is generally between 6 and 19 months, regardless of therapeutic interventions. Most patients die from local tumor extension and respiratory failure. Also, tumor invasion may cause heart failure, stroke, arrhythmias, or even small bowel obstruction.
The prognosis is generally poor with a median survival rate of four months for patients with metastatic disease and sixteen months for those with localized disease.With a latency period of 20-40 years from exposure to presentation as well as symptoms which are often confused with other diseases, malignant mesothelioma frequently spreads beyond local disease before the patient presents with symptoms.Prognosis after treatment often depends on how completely the tumor was resected in surgery.
There are four measures of cytoreduction:
CC-0 in which no tumor is visualized
CC-1 in which nodules are seen but less than 2.5 cm; these are likely to respond to chemotherapy
CC-2 in which nodules between 2.5 and 5 cm persist
CC-3 in which nodules greater than 5cm cannot be resected. Chemotherapy and radiation may help increase rate of survival.