Mesothelioma is a tumor malignant uncommon that affects the cells of the mesothelioma,
a protective membrane that covers most internal organs of the body including the pleura, peritoneum and pericardium.
Its most common form is malignant pleura mesothelioma. This is a so-called primitive form of pleura cancer, which is characterized by a multiplication of cancer cells in the tissue constituting the pleura. The pleura is a membrane that surrounds the lungs, consisting of two layers, one covering the lungs (inner leaflet or visceral pleura), the other lines the inside of the thoracic cavity (outer sheet or parietal pleura). When the disease occurs, pleura thickening, taking a scalloped appearance and the space between these two layers (pleura space) can fill with fluid and cause difficulty breathing.
An estimated 906 new cases of cancers of the pleura in 2005 in France, of which 71% occur in humans. Six new cases out of 10 are diagnosed in people over 69 years. The most recent data show 1090 deaths per year.
Asbestos as the main cause
80% to 85% of mesothelioma are related to exposure to asbestos, mainly occupational, but also environmental. This exposure may have occurred decades before the development of the disease. Multiple factors influence the onset of mesothelioma:
the time elapsed from the beginning of the exhibition
the cumulative dose of asbestos and is expressed in fibers per milliliter (mL) of air multiplied by the number of years of exposure to occupational exposures, and fibers per liter of air multiplied by the number of years of exposure for exposure of the general population;
the size and geometry of the fibers determine the penetration of the asbestos in the airways and their bio persistence : the most harmful fibers correspond to a length greater than 5 micrometers (microns) and a diameter less than 0.5 .mu.m
Asbestos is the only known risk factor for pleura mesothelioma (classified Group 1 carcinogenic to humans by the IARC ); except criterion, natural mineral fiber of the family of zeolites , which is also a recognized risk factor, which is present only in some parts of Turkey.
The occurrence of mesothelioma in the absence of asbestos exposure, is also possible (it affects about one in a million).
Other risk factors discussed
Other potential factors are discussed and need to be confirmed: some synthetic mineral fibers refractory ceramic types, exposure to ionizing radiation , the SV 40 virus or chemical agents such as bro mate, treasonous, minestrone.
The role of individual genetic susceptibility factors is likely but no mesothelioma susceptibility gene has been identified. Unlike the case of lung cancer, tobacco exposure has not been demonstrated in the risk of developing mesothelioma.
The compensation as an occupational disease
In case of suspicion of exposure to asbestos at the professional activity, it is recommended to start a recognition procedure occupational disease . Tables of occupational disease No. 30 the general scheme and 47 from the agricultural scheme provide for compensation to victims.
Evidence of exposure is not necessary, mesothelioma diagnosis authentic . If recognized as an occupational disease, the worker has a right to stop prematurely its business from 50 years, and compensation by the FIVA aimed at repairing the damage suffered by the worker or his heirs . This compensation FIVA is also given to non-employees, environmental victims and dependents.
strengthened public health policies
Mesothelioma are the subject of a national surveillance program of 22 departments and comprehensive record of all incidents mesothelioma complete a specific national register called national multi center registry of pleura mesothelioma (Meson at).
The health plan at work 2005 - 2009 (and from 2010 to 2014 in preparation), the second national environmental health map and the 2009 Cancer Plan - 2013 include all policies and risk prevention measures related to general environment and work. Thus, improving the observation and monitoring of the work environment-related cancers is an action plan in 2009 cancer - 2013 including a measure to mandatory reporting mesothelioma.
By Decree No. 2012-47 of 16 January 2012, mesothelioma are added to the official list of notifiable diseases. This mandatory declaration is implemented by the Institute of Health Surveillance (VS) at the request of the Ministry of Health. Any new cases of mesothelioma, whatever the anatomical site (pleura, peritoneum, pericardium ...), will now be notified to the doctor Regional Health Agency (ARS), by any physician (pathologist or clinician) working in France or ultramarine and who makes the diagnosis.
Note also that as part of the Cancer Unit and Environment Center Léon Barnard (Centre against the cancer Lyon and Rhône-Alpes), a consultation "occupational cancer" was set up in collaboration with the Pathology Consultation Center for professional Hospices Civil de Lyon, so patients of the Center Lon Barnard can benefit from a systematic research approach of occupational exposures in cancer compensate occupational disease, particularly among patients with cancer lung and mesothelioma.
Editorial Sources: Anses ; CIRC; INCA ; INSERM ; InVS .
Author : Cancer Unit and Environment