Mesothelioma - Research Paper Example

Benign mesothelioma originates from sub-mesothelial fibroblasts and is not connected to its malignant counter-part in any way. Site of origin is mostly visceral and parietal pleura and it grows in a slow fashion with no etiological relationship to asbestos. Benign mesothelioma can be treated quite effectually with surgical excision. Recurrence can be avoided if proper margins are excised. The etiology of malignant mesothelioma differs from the benign one. It has a strong co-relation with asbestos in its etiology.

Exposure to asbestos can be due to environmental exposures or occupational reasons. When asbestos is deposited in the pleura of the lungs, or if inhaled it can lead to the mesothelioma of the pleural cavities. Various forms of asbestos have been established as the cause of this cancer. These include crocidolite asbestos, amosite asbestos and anthophyllite asbestos (Bouros 2004). An estimate of 50 percent of individuals diagnosed with mesothelioma, show a positive history of asbestos exposure.

Most of these people are shipyard workers, miners or insulators. The development of asbestos in such individuals who are at great risk occurs after approximately a time period of 25 to 40 years. This points towards the genetic events that accumulate towards the development of carcinogenic mesothelial cells after asbestos exposure (Kumar et al 2007). The carcinogenic properties of asbestos have yet not been clearly understood by the medical world. Asbestos cannot be metabolized and also remains for lifetime in the lungs once inhaled.

Therefore, after inhalation or deposition of asbestos, there is a lifetime risk of mesothelioma even when the exposure has been discontinued. Asbestos causes the release of reactive oxygen species (ROS). These reactive oxygen species attack the DNA of the mesothelial cells causing damage to the DNA. Furthermore, the ROS also initiate the genetic mutations in these cells leading to cancer. Two important tumor suppressor genes undergoing mutation are p16/CDKN2A and NF2 which are always recognized in malignant mesothelioma.

Recently another factor, simian virus 40 viral DNA matter has been recognized in 80 percent of the mesothelioma cases. This highlights its strong co-relation with the occurrence of mesothelioma. The simian virus binds to the growth factor regulator genes and hence inhibits them. These include the p53 and RB genes (Kumar et al 207). Other causes which are considered as risk factors are radiation therapies, hereditary factors, immunosuppressive diseases like HIV, chronic inflammatory diseases like TB pleurisy and dietary factors (Bouros 2004).

The most characteristic clinical manifestations of malignant mesothelioma are shortness of breath (dyspnea) and chest pain. Non-specific symptoms are associated with them which include night sweats, weight loss, fatigue, malaise, fever, chills and anorexia. Along with mesothelioma findings, some individuals also present with an additional finding of pneumothorax. Other less common additional findings observed after research were, anemia, diabetic complications, empyema, metastatic disease and acute abdomen.

The prognosis of this malignancy is poor and patients die within the time duration of one year. Some patients may show an increased survival rate for up to three years and a very few patients may survive till 10 years or