It affects predominantly male individuals (70% of total cases) of 40-60 years of age, located mainly in the dorsal and basal pleura. This is a primary tumor, namely, that is formed directly in the pleural tissue thin and not for the spread (metastasis) to other cancers originated in other organs.
Causes: asbestos and other mineral fibers
The outbreak appears to be highly correlated long-term exposure to mineral fibers, particularly asbestos and fluoroedenite. All steps in the processing of minerals from which they derive, extraction is sorted by carding to spinning fibers, and manipulation of derivatives to perform insulation, are considered highly risky for the development of cancer cells, damage mineral fibers are not immediate, but occur on average after three decades.
It is not yet known the mechanism by which the microscopic mineral fibers are able to migrate passively from bronchioles to the alveoli to the pulmonary pleural space, and perpetrators of thickening, calcification and asbestosis, ignite the oncogenic process. They may act as agents of inflammation from mechanical, chemical, or as free silicic acid which has similar necrotizing, or again, can act as catalysts of reactions from which they develop carcinogens.
The incidence of mesothelioma of the pleura is particularly high in Western Europe, where currently there are about five cases a year, specialists provide a peak around 2020, caused by the latency of the disease, followed by a rapid decrease resulting the rules in the early nineties banned the use of asbestos (in Italy, this happened with the law 257/92). In our country the death rate is among the highest in the world, especially in Northern Italy and Campania, ie where, before the entry into force of the law, it was massive use of mineral fiber insulation: in the shipyards, railway workshops, workers used in building material, however, were also at risk family members of workers who breathed the tiny fibers deposited on clothing of these.
Other causes
In the absence of un’accertata exposure to asbestos, the cause of mesothelioma can be sought from pleurisy, chronic smoking and exposure to ionizing radiation. Recent studies have shown a possible link between the disease and the virus SV-40 that in the sixties was used for the preparation of polio vaccine. Again, it is believed that the thin fibers, migrated from the lung tissue to the pleural membrane, are engulfed by macrophages in which induce biochemical changes and abnormal cells, development of cancerous cells.
Symptoms and Treatment
Mesothelioma causes a significant thickening of the pleural membranes, including those of several centimeters, and the gradual closing of the gap between the two layers, which over time creates thick deposits of fluid, gray. The tumor ends up mechanically forcing the lungs, which tends to collapse, losing its functionality (atelectasis). The first symptoms are pleural effusion, chest pain, difficult breathing, disease progression leads to fever, cough, loss of weight and chest deflection where the pleura is affected.
Therapy
Although pleural mesothelioma not now gives hope of complete recovery, its evolution depends, as for many types of cancer, timeliness of diagnosis and aggressiveness of treatment that can prolong patient survival. Therapeutic results depend greatly on the stage of disease, the patient’s age, the amount of lymph nodes involved by the tumor. The techniques used are surgery, with removal of the pleura (pleurectomia) of the pleura and lung (pleuropneumonectomia) with talc or closing of the gap between the two pleura to avoid payments (pleurodesis), radiotherapy or chemotherapy. More recent studies suggest that only one type of therapeutic approach has not resulted in satisfactory changes in survival are more favorable prognosis could be expected following combination therapy, which embraces all three approaches mentioned. Are also ongoing trials of photodynamic therapy applied to mesothelioma.
Tags: Cancerous cells, Disease, Polio Vaccine, Symptoms and Treatment, The Mesothelioma, Therapy
