INTRODUCTION: Mesothelioma is a form of cancer that is almost always caused by previous exposure to asbestos. Most people who develop it have worked on jobs where they inhaled asbestos particles, or they have been exposed to asbestos dust and fibre in other ways, such as by washing the clothes of a family member who worked with asbestos.
It is an extremely serious disease with an average survival time of about 1 to 2 years after diagnosis. Unlike lung cancer, there is no relationship between mesothelioma and smoking. The condition occurs more frequently in men than in women and risk grows with age, however this disease can appear in either men or women at any age. It is also known to happen in those who are genetically pre-disposed to it.
SYMPTOMS: The disease may not appear until 20 - 50 years after exposure to asbestos. Diagnosing it can be hard, because the symptoms are similar to those of a number of other diseases. The signs of mesothelioma include shortness of breath due to pleural effusion (fluid between the lungs and the chest wall) or a painful chest wall , and more general symptoms such as loss of weight.
Signs of the condition may also include abdominal pain, ascites, or an un-explained buildup of fluid in the abdomenal mass in the abdomen, problems with bowel function. Other signs of peritoneal mesothelioma may include obstruction of the bowel, abnormal blood clotting, anemia, and fever.
If the cancer has metastatized beyond the mesothelium to other parts of the body,possible signs may include pain, trouble with swallowing, or swelling of the neck or face.
In severe cases of the disease, the following signs and symptoms may be present: blood clots in the veins, which may cause thrombophlebitis, disseminated intravascular coagulation, a disorder causing severe bleeding in many body organs, jaundice, or yellowing of the eyes and skin, low blood sugar level, pleural effusion, pulmonary emboli, or blood clots in the arteries of the lungs, severe ascites. These symptoms may be caused by mesothelioma or by other, less serious conditions.
TREATMENT: There are number of types of treatment options available: Radiation, Surgery, and chemotherapy including newly approved medications. Despite treatment with chemotherapy, radiation therapy and sometimes surgery, the disease has a poor prognosis. For those with localized disease, and who can tolerate a radical surgery, radiation is usually given post-operatively as a consolidative treatment.
Although the cancer is usually resistant to curative treatment with radiotherapy alone, palliative treatment regimens are sometimes used to relieve symptoms caused by tumor growth, such as obstruction of a major blood vessel. In February 2004, the U.S. Food and Drug Administration approved pemetrexed (brand name Alimta) for treating malignant pleural mesothelioma.
CONCLUSION: Mesothelioma is a kind of cancer that is most often caused by previous exposure to asbestos. If it affects the pleura it can cause these signs and symptoms: pain in the chest wall, pleural effusion, or fluid surrounding the lungs, shortness of breath, fatigue or anemia, wheezing, hoarseness or cough, blood in the sputum (fluid) coughed up (hemoptysis).
It is described as localized if the cancer is found only on the membrane surface where it originated. Screening tests might diagnose mesothelioma earlier than conventional methods thus improving the survival prospects for patients.
The processes leading to the development of peritoneal mesothelioma remain as yet unknown, although it has been suggested that asbestos fibres from the lung are transported to the abdomen and associated organs via the lymphatic system.
It has been argued that in humans, transport of fibres to the pleura is critical to the pathogenesis of the condition.
Experimental evidence suggests that asbestos acts as a complete carcinogen with the development of mesothelioma occurring in sequential stages of initiation and promotion.
Although reported incidence rates have risen in the past 2 decades, the disease is still a relatively rare occurence. Incidence of malignant mesothelioma presently ranges from about 7 to 40 per 1 million in industrialized Western nations, depending on the amount of asbestos exposure of the populations during the past several decades.
Between 1973 and 1984, there has been a threefold increase in the diagnosis of pleural mesothelioma in Caucasian males. From 1980 to the late 1990s, the death rate from mesothelioma in the USA increased from 2,000 per year to 3,000, with men four times more likely to acquire it than women. These rates may not be accurate, since it is possible that many cases are mis-diagnosed as adenocarcinoma of the lung, which is difficult to differentiate from mesothelioma.
Working with asbestos is the major risk factor for mesothelioma. However, the disease has been reported in some individuals without any known exposure to asbestos. In addition to mesothelioma, exposure to asbestos increases the risk of lung cancer, asbestosis (a noncancerous, chronic lung ailment), and other cancers, such as those of the larynx and kidney.
Smoking modern cigarettes does not seem to increase the risk of developing the disease. The Kent brand of cigarettes used asbestos in its filters for the first few years of production in the 1950s and a few cases of mesothelioma have resulted.