The most common form of mesothelioma is malignant pleural mesothelioma, the so-called “primary form” of pleural cancer. 80 to 85% of mesothelioma cases are due to an exposure to asbestos that may have occurred several decades before the development of the disease. Exposure to asbestos is mainly of occupational origin, but it can also be environmental (presence of asbestos in certain soils and their surroundings). Surviving Mesothelioma is not easy but it’s possible.
Mesothelioma is a rare malignant tumor that affects the cells of the mesothelium, a protective membrane that covers most of the body’s internal organs including the pleura, peritoneum, and pericardium. Its most common form is malignant pleural mesothelioma.
Mesothelioma is a so-called primitive form of pleural cancer, which is characterized by a multiplication of cancer cells in the tissue constituting the pleura. The pleura is a membrane that envelops the lungs, consisting of two layers, one covers the lungs (inner leaflet or visceral pleura), the other covers the inside of the chest cavity (outer leaf or parietal pleura). When the disease occurs, the pleura thickens, takes on a scalloped appearance and the space between these two leaflets (called the pleural cavity) can fill with fluid and cause breathing difficulties.
Six out of every 10 new cases are diagnosed in people over 69 years of age. The most recent data show thousands of deaths per year.
Asbestos as the main cause
Multiple parameters influence the appearance of mesothelioma:
- The time elapsed and the cumulative “dose” of asbestos. The dose is expressed in fibers per milliliter (mL) of air multiplied by the number of years of occupational exposure, and in fibers per liter of air multiplied by the number of years of exposure for general population exposures.
- The peak of exposure is also important. The size and geometry of the fibers determine how the asbestos penetrated the respiratory tract and also included its bio-persistence. The most harmful fibers correspond to a length greater than 5 micrometers and a diameter of fewer than 0.5 micrometers.
Asbestos is the only recognized risk factor for mesothelioma in the pleura. Apart from erionite, a natural mineral fiber from the zeolite family, which is also a recognized risk factor, is only present in a couple parts of the world.