Typical survival despite surgery is between 12 and 21 months depending on the stage of disease at diagnosis with about 7.5% of people surviving for 5 years.Women, young people, people with low-stage cancers, and people with epithelioid cancers have better prognoses. Negative prognostic factors include sarcomatoid or biphasic histology, high platelet counts (above 400,000), age over 50 years, white blood cell counts above 15.5, low glucose levels in the pleural fluid, low albumin levels, and high fibrinogen levels. Several markers are under investigation as prognostic factors, including nuclear grade, and serum c-reactive protein. Long-term survival is rare.Pericardial mesothelioma has a 10-month median survival time.In peritoneal mesothelioma, high expression of WT-1 protein indicates a worse prognosis. Epidemiology
Although reported incidence rates have increased in the past 20 years, mesothelioma is still a relatively rare cancer. The incidence rate varies from one country to another, from a low rate of less than 1 per 1,000,000 in Tunisia and Morocco, to the highest rate in Britain, Australia and Belgium: 30 per 1,000,000 per year. For comparison, populations with high levels of smoking can have a lung cancer incidence of over 1,000 per 1,000,000. Incidence of malignant mesothelioma currently ranges from about 7 to 40 per 1,000,000 in industrialized Western nations, depending on the amount of asbestos exposure of the populations during the past several decades. Worldwide incidence is estimated at 1-6 per 1,000,000.
Pneumatosis is the abnormal presence of air or other gas within tissues.In the lungs, emphysema involves enlargement of the distal airspaces, and is a major feature of chronic obstructive pulmonary disease (COPD). Other pneumatoses in the lungs are focal (localized) blebs and bullae, pulmonary cysts and cavities. Pneumoperitoneum (or peritoneal emphysema) is air or gas in the abdominal cavity, and is most commonly caused by gastrointestinal perforation, often the result of surgery. Pneumarthrosis, the presence of air in a joint, is rarely a serious sign. Lung cysts
A lung cyst, or pulmonary cyst, encloses a small volume of air,  and has a wall thickness of up to 4 mm. A minimum wall thickness of 1 mm has been suggested, but thin-walled pockets may be included in the definition as well. Pulmonary cysts are not associated with either smoking or emphysema.A lung cavity has a wall thickness of more than 4 mm. Other thoracic
Pneumothorax, air or gas in the pleural space
Pneumomediastinum, air or gas in the mediastinum
Also called mediastinal emphysema or pneumatosis/emphysema of the mediastinum

Abdominal
Pneumoperitoneum (or peritoneal emphysema), air or gas in the abdominal cavity. The most common cause is a perforated abdominal viscus, generally a perforated peptic ulcer, although any part of the bowel may perforate from a benign ulcer, tumor or abdominal trauma. Pneumatosis intestinalis, air or gas cysts in the bowel wall
Gastric pneumatosis (or gastric emphysema) is air or gas cysts in the stomach wall

Joints
Pneumarthrosis is the presence of air in a joint.