INTRODUCTION: Mesothelioma is a type of cancer that is nearly always brought about by previous exposure to asbestos. The majority of people who develop it have inhaled asbestos particles while being employed on a job where asbestos is used, or they have been exposed to asbestos dust and fibre in some other way, such as by washing and cleaning the clothes of a family member who worked with or around 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 disease is normally resistant to curative treatment with radiotherapy alone, palliative treatment regimens are sometimes used to ease symptoms arising from tumor growth, such as blockage of a major blood vessel. In February 2004, the United States FDA approved pemetrexed (brand name Alimta) for treatment of cancerous pleural mesothelioma.
CONCLUSION: Mesothelioma is a type of cancer that is nearly always caused by previous exposure to asbestos. Cancer that affects the pleura can cause these signs and symptoms: A painful 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 condition is found only on the membrane surface where it started. Screening tests might diagnose mesothelioma earlier than conventional methods thus increasing the survival prospects for patients.
The processes leading to the development of peritoneal mesothelioma remain unresolved, although it has been proposed that asbestos fibres from the lung are transported to the abdomen and associated organs via the lymphatic system.
It has been suggested that in humans, transport of fibres to the pleura is critical to the pathogenesis of the disease.
Experimental evidence suggests that asbestos acts as a total and complete carcinogen with the development of mesothelioma occurring in sequential stages of initiation and promotion.
Although reported incidence rates have increased in the past 20 years, the disease is still a relatively rare cancer. 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.
Between the years 1973 and 1984, there has been a threefold growth in the diagnosis of pleural mesothelioma in white males. From 1980 to the late 1990s, the death rate from mesothelioma in the United states increased from 2 thousand per year to 3 thousand, with men four times more likely to acquire the disease 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 hard to differentiate from mesothelioma.
Working with asbestos is the greatest risk factor for mesothelioma. However, the disease has been reported in some persons without any known exposure to asbestos. In addition to mesothelioma, exposure to asbestos raises the risk of lung cancer, asbestosis (a noncancerous, chronic lung ailment), and other malignancies, such as those of the larynx and kidney.
Smoking modern cigarettes does not appear 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 some cases of mesothelioma have resulted.