Mesothelioma is a cancer of the mesothelium. The mesothelium is a membrane, a thin layer of tissue, that cover the internal organs of the body.
Depending on what region of the body this membrane covers, the mesothelium is given different names:
- The Peritoneum covers the organs in the abdominal area.
- The Pleura or Pleural is a sac which covers the lungs and lines the chest cavity.
- The Pericardium covers the heart.
Like other cancers, mesothelioma may be benign or malignant (cancerous). It is rare for mesothelioma to be benign. In its malignant state, malignant mesothelioma (MM) may be referred to as a tumor. This tumor will grow and may spread (metastasize) cancerous cells to other parts of the body, damaging tissue and organs.
According to Dr. Winston Tan, Assistant Professor of Medicine at Mayo Medical School, 90% of all malignant mesothelioma cases start in the lungs (pleura).
Risk Factors
The largest risk factor for mesothelioma is having worked with asbestos in the past. Asbestos is a naturally occurring mineral that has been mined since the 1800s. Its usage increased during World War II. Although asbestos use is now reduced or banned, industrial industries such as the following used asbestos in the past:
- ship building
- cement manufacturing
- paper milling
- brake lining
- railroad repair
- home insulation
If asbestos particles are inhaled or swallowed, as would occur during the manufacturing process, these microscopic particles can build up and penetrate the lungs entering into the pleural cavity. In turn, these asbestos particles may cause cancerous tumors. According to Dr. Tan, 80% of all patients in the United States with mesothelioma have had exposure to asbestos. "Malignant mesothelioma has a peak incidence 35-45 years after asbestos exposure."
Frequency and Mortality Rate
There are up to 3,000 cases of mesothelioma diagnosed per year according to Dr. Tan. It is more common among men than women, generally occurring between the ages of 50 and 70.
The use of tobacco, alcohol and other dietary factors seem to have no effect on the frequency of developing mesothelioma.
Mesothelioma is almost always fatal. The median survival rate of those with mesothelioma is 11 months.
Symptoms and Diagnosis of Mesothelioma
Symptoms may not occur for decades after exposure to asbestos. Compounding the problem is the fact that there may be no symptoms or many of the symptoms may be mistaken for other medical conditions or ignored altogether for years.
Symptoms include:
- 60-90% experience chest pain
- fatigue
- fever
- sweats
- weight loss
These symptoms may be confused with the common cold, the flu or pneumonia.
In order to confirm the diagnosis of mesothelioma a biopsy, or tissue sample, is needed. According to the location of the cancer, different approaches may be taken by the doctor to remove a sample of tissue for examination, beginning with the least intrusive method of surgery.
Mesothelioma is either localized (remaining only where the cancer began) or advanced (spreading to other areas of the body).
Mesothelioma Treatment
There are three standard treatments for mesothelioma. These treatments may be combined (trimodality therapy).
- Surgery: Part of the chest or abdomen lining and tissue may be removed. If the cancer is in the lungs (pleural), the lung may be removed (pneumonectomy). The recurrence rate after surgery is "very high and most patients die after a few months" according to Dr. Tan.
- Radiation therapy: These powerful rays kill the cancer and shrink the tumor. This type of treatment may lead to other health issues. While radiation therapy does not cure mesothelioma, there is a reduction of pain in 50% of patients treated with radiation for chest pain.
- Chemotherapy: This is the use of powerful drugs to kill cancer cells in the body. Cisplatin is a common anti-cancer drug. While Cisplatin kills the cancerous cells, it also damages healthy cells in the process.
- Trimodality therapy: This is a combination of all three treatment options listed above. Dr. Tan states with trimodality therapy, the "survival rates were 45% at 2 years and 22% at 5 years."
Dr. Winston Tan comments on therapy, "Currently, no therapy is considered standard. The standard methods of surgery, radiation, or chemotherapy alone have not improved survival."
Asbestos Manufacturers and Lawsuits
It is widely alleged that asbestos manufacturers knew of the dangers of asbestos as early as the 1920s and engaged in covering up the potential deadly effects as early as the 1930s.
According to the American Insurance Association there have been over 600,000 asbestos lawsuits filed that have bankrupted almost 70 companies.
Sources:
Winston, T. (2010). Mesothelioma. Emedicine.
Mesothelioma: Questions and Answers. National Cancer Institute.
Blair Kasfeldt - Helping you with the best article on mnemonics (memory devices), theological issues and more. If you are facing a "memory problem" ...
Join the Conversation