Mesothelioma is a rare form of cancer (malignancy) that most frequently arises from the cells lining the sacs of the chest (the pleura) or the abdomen (the peritoneum).
Pleural mesothelioma is the most common form, often presenting with symptoms in the chest area. Peritoneal mesothelioma is much less common.
This can effect the organs in the abdomen, and its symptoms are related to this area of the body, that is, abdominal swelling, nausea, vomiting, and bowel obstruction. The rarest form of mesothelioma is pericardial mesothelioma, which involves the sac surrounding the heart.
There are two major cell types of mesothelioma, epithelial and sarcomatoid. Sometimes both of these cell types can be present. The sarcomatoid type is rarer and occurs in only about 15% of cases; it portends a poorer prognosis. In very rare cases, mesothelioma can originate from benign, non-malignant cells. This so-called benign mesothelioma can be cured surgically.
Most people present with complaints of shortness of breath. They also can have complaints of chest pain. Surprisingly, this pain is often not pleuritic; that is, it does not get worse with deep breathing.
This is surprising in that the pleura (outer surface of the lung) is often involved in this disease, and most other diseases involving the pleura are often associated with pleuritic pain (pain that worsens with deep breathing). Patients may also be asymptomatic, with the disease discovered by physical exam or an abnormalchest X-ray.
As the disease progresses, shortness of breath increases, and weight loss, decreased appetite, and night sweats can develop. Local invasion by the tumor can result in changing of voice, loss of function of the diaphragm, and symptoms specific to the area and involvement of adjacent structures.
Most people with malignant mesothelioma have worked on jobs where they breathed asbestos. Usually, this involves men over 40 years of age. Others have been exposed to asbestos in a household environment, often without knowing it.
Interestingly, the number of new cases of mesothelioma has been relatively stable since 1983, the same time that the restrictions on asbestos were instituted by the U.S. Occupational Safety and Health Administration (OSHA).
In Europe, the number of new cases of mesothelioma continues to rise.
There are three traditional kinds of treatment for patients with malignant mesothelioma.
Often two or more of these are combined in the course of treatment:
• surgery (taking out the cancer),
• radiation therapy (using high-dose X-rays or other high-energy rays to kill cancer cells),
• chemotherapy (using drugs to fight the cancer).
There are several types of surgery used in treating mesothelioma.
A pleurectomy is the removal of part of the chest or abdomen lining and some of the tissue around it.
Depending on how far the cancer has spread, a lung also may be removed in an operation called a pneumonectomy.
In an extrapleural pneumonectomy, the lung is removed along with the lining and diaphragm (the muscle that helps you breathe) on the affected side. In this surgery, the lining around the heart is also removed.
Sometimes a pleurectomy/decortication is performed. In this surgery, the lining of the lung is removed along with as much of the tumor as possible.
Radiation therapy uses high-energy X-rays to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external radiation therapy) or from putting materials that produce radiation (radioisotopes) through thin plastic tubes in the area where the cancer cells are found (internal radiation therapy).
If fluid has collected in the chest or abdomen, your doctor may drain the fluid out of your body by putting in a needle into the chest or abdomen and using gentle suction to remove the fluid. If fluid is removed from the chest, this is called thoracentesis.
If fluid is removed from the abdomen, this is calledparacentesis. Your doctor may also put drugs through a tube into the chest to prevent more fluid from accumulating.
Chemotherapy is the use of drugs to kill cancer cells. Chemotherapy may be administered by pill, or it may be put into the body by a needle in the vein or muscle.
Chemotherapeutic agents can be administered either systemically (through the bloodstream) or intrapleurally (in the pleural cavity). When it is administered intrapleurally, the treatment is localized at the site of the tumor. These drugs are generally very toxic and you should discuss their use very carefully with your physician.