"Mesothelioma" is the term used to describe a cancerous tumor that involves the mesothelial cells of an organ. Mesothelial cells are cells that form a protective lining over the lungs, heart and abdominal organs. The most common type of mesothelioma is pleural mesothelioma. The pleura is a thin membrane found between the lungs and the chest cavity. It provides a lubricated surface so that the lungs do not rub and chafe against the chest walls.

What causes it?
Virtually all cases of mesothelioma are related to inhaling of asbestos fibers. There are about 3,000 cases per year (mostly men over the age of 40) and there will be about 300,000 cases before 2030. Mesothelioma usually spreads rapidly through the mesothelial cells to the heart and abdominal organs. The life span is typically 24 months after diagnosis, but it depends on what stage the cancer is detected, the health of the patient and other factors.

Although asbestos exposure causes mesothelioma, it has a latency period after exposure that could last 15 to 50 years. This means that someone who worked in a factory with asbestos 40 years ago could be developing mesothelioma now. Anyone who knows they were exposed to loose asbestos fibers should be tested regularly for mesothelioma.

Diagnosis
The onset of mesothelioma is usually very slow. The first symptom is a constant pain in the chest. This pain is later accompanies by difficulty breathing due to an accumulation of fluid in the chest. Other symptoms include coughing, fever and weight loss. Mesothelioma can be diagnosed by your doctor with a chest CT-scan.

Prognosis (the outcome)
Mesothelioma advances in 4 stages:
Stage I - the tumor is limited to the area of the lining of the lung and usually limited to only one side of the chest.
Stage II - the tumor extends to other organs within the chest cavity, such as the heart or lymph nodes in the chest.
Stage III - the tumor expands to the other side of the chest or it spreads into the abdominal organs. The lymph nodes outside the chest are affected.
Stage IV -the cancer spreads to different parts of the body far outside the chest area (liver, brain, bone, etc...).

Mesothelioma is an extremely deadly disease. The average survival time is about one year from date of diagnosis. About 20% of patients who find their cancer early and treat it aggressively will reach the five-year mark.