Mesothelioma - cancer that originates from the mesothelium, or from the one cell layer that acts as a coating of the membranes earnest (pleura, pericardium, peritoneum, etc..).The Mesothelioma is a tumor that most authors consider rare, but not everyone agrees with this view. The best known and most widespread form of mesothelioma is pleural mesothelioma , cancer that originates from mesothelial cells of the pleura (is calledpleural membrane that earnest that completely covers the lungs - pleura - and the cavity of the chest - pleural parietal). Other forms of mesothelioma ( peritoneal mesothelioma ,pericardial mesothelioma , mesothelioma of the serous lining the testis ) are much less frequent. Pleural mesothelioma accounts for about 80% of all mesothelioma cases, and so this type of cancer will be the subject of this article. The appearance of a pleural mesothelioma is strongly related to exposure to ' asbestos (a substance known asasbestos ); Pleural mesothelioma is a cancer of the extreme gravity of the poor prognosis, the survival time from diagnosis is not particularly long (1-2 years.) One of the most "interesting" of pleural mesothelioma is the length of the latency period between exposure to asbestos and its appearance, a period that, on average, from 15 to 45 years (as has been observed even much longer latency periods.) That the appearance of a pleural mesothelioma is closely linked to past exposure to ' Asbestos is a truth universally accepted, but nevertheless there are no screening methods universally codified and approved, at least in those in which the exposure is unknown. Several studies have been performed to identify the existence of markers of exposure, the marker which focused more research is mesothelin, a glycoprotein whose presence in serum was found to be higher in those who have suffered exposure to ' asbestos and who later were affected by mesothelioma. The increase in serum levels of mesothelin is however not sufficient in itself to diagnose with certainty the presence of the disease in question.
The causes of pleural mesothelioma
As said, the pleural mesothelioma is one of the cancers in which has been clearly demonstrated a close correlation with the exposure to asbestos fibers (exposure which among other things is also linked to several other more or less serious diseases such as asbestosis, lung cancer and so on. For further details please see our article Asbestos paragraph pathologies by exposure to asbestos ). Asbestos fibers are very thin fibers that penetrate into the human body through the mechanism of respiration, the asbestos fibers can then reach the lungs and pleura and may also exert their actions at these sites fibrogena and carcinogenic. The fact that the latency between exposure and onset of the disease is, as already mentioned, definitely makes the high number of mesothelioma cases that are recorded is constantly increasing (the law prohibiting the various uses of asbestos dates back to 1992) . It is believed that in Italy, according to estimates accurate enough, cases of pleural mesothelioma will have their peak in 2015 and then begin to decrease slowly. In some regions of our country, the incidence of mesothelioma is much higher than in other, between these regions there are Liguria, Lombardy, Piedmont and Puglia regions where the asbestos processing was greater than in other areas. A wide literature exists on pleural mesothelioma, a disease that falls within the circle of the so-called "occupational diseases "shows that there are several cases of mesothelioma in subjects not directly exposed to asbestos. For those not directly exposed to asbestos include those who were not classified as workers in companies that dealt with the material and that residents in areas with asbestos quarries, residents in areas with industries that were working and also the families of those who worked in the field (for this reason it is also called pleural mesothelioma tumor proximity or cancer family ), the diagnosis of mesothelioma in different families of workers in the asbestos industry did suggest that even very high concentrations of asbestos fibers ( for example those found on the clothes of family members of workers) can be quite dangerous. It is for this reason that today it is not possible to define with certainty a minimum level of exposure that can be considered "safe." virus SV 40 - The vast majority of mesotheliomas in exposure to asbestos fibers recognizes the cause the pathology, however, is also true that only a small percentage of those exposed developed mesothelioma (about 5%), which has led to the suggestion that there may be other contributing factors. One of these may be a virus, the SV40 ( Simian Virus 40 ), a virus is described for the first time in 1960 in a cell culture of macaque that were used to obtain the polio vaccine. Several studies have shown that the intrapleural injection of Simian virus 40 induces malignant mesothelioma in 100% of the guinea pigs regardless of whether or not they have been exposed to asbestos fibers. Some viral sequences were detected in samples of human mesothelioma. Some speculate that the two factors (exposure to asbestos fibers and viruses) act jointly and that the asbestos fibers promote the carcinogenic action of SV40. However, there is still evidence on the possible pathogenic role of this virus. Symptoms and Diagnosis of pleural mesothelioma
The symptoms of pleural mesothelioma is rather non-specific in fact many of the symptoms are common to many other diseases, among other things, given the long latency period between exposure to asbestos fibers and the onset of symptoms, it is not always immediately bring them back to previous exposure.
Symptoms that occur with more frequency in pleural mesothelioma are shortness of breath, chest pain and persistent cough, usually fractious. More rare are the weight loss and fever. Among other things, some people, even in the presence of the disease, they do not show any kind of symptoms and the disease is discovered incidentally during radiological controls carried out for other reasons.
Respiratory symptoms are generally caused by pleural effusion - that is, it has an excessive accumulation of fluid in the space that exists between the so-called pleural - or by thickening of the latter.
Diagnosis of mesothelioma is often performed when mesothelioma is already in its more advanced stages because, as I said at the beginning of the paragraph, the symptoms are often bland and not very specific. Staging - Staging of mesothelioma most used internationally is that dell'IMIG ( International Mesothelioma Interest Group ), which we summarize briefly in a very schematic way: Stage I - Mesothelioma confined to the parietal pleura or the parietal with the visceral pleura on one side only, with no lymph node involvement. Stage II - Mesothelioma confined to the parietal and visceral pleura on one side only, but more extensively than the staging I. Even at this stage there is no lymph node involvement. Stage III - In this stage mesothelioma affects extensively the visceral and parietal pleura (and may also involve other structures such as the pericardium tissue or the chest wall), you also have lymph node involvement.Stage IV - At this stage you have the involvement of the contralateral pleura or pleural fluid containing tumor cells or the involvement of bony structures (ribs or spine) or other organs outside of the rib cage. For the diagnosis of mesothelioma 'performing radiological examinations does not give the diagnostic certainty that can only be achieved through biopsy. The biopsy may reveal one of the three histological types of mesothelioma currently coded: epithelioid mesothelioma, sarcomatoid mesothelioma and mesothelioma mixed (or biphasic).
Treatment of mesothelioma
We distinguish two main types of treatment for mesothelioma, one traditional and one that takes advantage of new therapeutic approaches.The second type is still under study is applied only in restricted clinical studies. Traditional treatment makes use of surgery , radiotherapy and chemioterapi to, sometimes in combination.
In a surgical setting, in cases in which the surgeon believes that there are conditions for an operation, you can groped two types of approach: pleurectomy / decortication (removal of the neoplastic mass and the pleura affected) and the extra-pleural pneumonectomy, an operation far more extensive and complex that also involves removal of the lung. The risk of relapse remains high in both approaches.
Radiotherapy has especially the role of integration of other approaches, it is sometimes useful in the control of symptoms.
approach may be useful in combination chemotherapy or radiotherapy is less than that before the 'surgery (you try to reduce the tumor mass to facilitate the work of the surgeon) and later as a consolidation of the results obtained.
remains, however, the fact that, to date, pleural mesothelioma is a cancer that involves considerable difficulties in treatment and in which Unfortunately, the prognosis is poor.
Post a Comment
EmoticonClick to see the code!
To insert emoticon you must added at least one space before the code.