Malignant Mesothelioma and Asbestos - Pleural Mesothelioma
Malignant Mesothelioma and Asbestos
Malignant mesothelioma is a cancer of the mesothelial tissue lining three of the body’s largest cavities: the pleura (lung cavity), the peritoneum (abdominal cavity) and the pericardium (heart sac).
Malignant mesothelioma is believed to be responsible for more than 200,000 deaths worldwide, with 2,000 to 3,000 new cases being diagnosed each year in the United States alone. The relatively rare cancer is a latent disease, meaning that it can take anywhere from 30 to 40 years to become fully developed and begin displaying symptoms. When diagnosed, malignant mesothelioma is often in an advanced stage, leading to a post-diagnosis survival time of between one and two years. The average age at diagnosis of mesothelioma is between 50 and 70 years old, with men being affected three to five times more often than women.
Malignant mesothelioma is typed in accordance with the section of the mesothelium that it affects; for example:
- Pleural mesothelioma is a cancer of the pleura (pleural tissue).
- Peritoneal mesothelioma is a cancer of the peritoneum (peritoneal tissue).
- Pericardial mesothelioma is a cancer of the pericardium (pericardial tissue).
Pleural mesothelioma is the most common of the three, accounting for an approximate 75% of all documented cases. A result of its close proximity to the lungs, pleural mesothelioma is often misdiagnosed as a type of lung disease, like asbestos lung cancer or viral pneumonia. In order to obtain a definitive pleural mesothelioma diagnosis, an examination of suspect tissue is required by a histopathologist.
Mesothelioma Treatments and Causes
Mesothelioma treatments have thus far been unable to contain the deadly cancer. Traditional mesothelioma treatment modalities are the same as those used to treat other types of cancer and include surgery, chemotherapy and radiation therapy. New mesothelioma treatment modalities are researched and developed with the hope of realizing more success than their traditional predecessors. New mesothelioma treatment modalities include photodynamic therapy, immunotherapy, gene therapy and intensity modulated radiation therapy; in addition to the development of new chemotherapy drugs.
Asbestos exposure is the only known cause of malignant mesothelioma. Although other causes have not been ruled out, asbestos exposure is the only verifiable cause. Asbestos exposure is the cause of a variety of diseases aside from malignant mesothelioma, some of which include asbestos lung cancer, asbestosis, diffuse pleural thickening and fibrosis.
Asbestos
Asbestos is a group of six naturally occurring fibrous metamorphic minerals: chrysotile, tremolite, amosite, actinolite, anthophyllite and crocidolite. Chrysotile asbestos was the type most commonly used for industrial purposes because of the fact that it is less friable and therefore less likely to be inhaled. This can be attributed to the fact that chrysotile asbestos is the only one of the six types with a serpentine fiber formation. Serpentine rocks have curled fibers as opposed to amphibole asbestos which has straight, needle-like fibers.
Prior to being regulated in the 1970s, asbestos was commonly used as an insulator throughout the twentieth century because of its resistance to heat and fire and high tensile strength and flexibility. A large number of buildings throughout the United States are still lined with asbestos insulation. This does not pose a health hazard unless the insulation has been torn or damaged in any way; in which case, removal or repair is an absolute necessity.
Asbestos products were commonly used for a variety of industrial and commercial purposes. Although common in the workplace, asbestos products were also extremely commonplace for the home, putting virtually everyone at risk of coming into contact with the hazardous mineral at one time or another.