Listen to an audio summary on Mesothelioma.
Mesothelioma is an aggressive cancer affecting the membrane lining of the lungs and abdomen.
Making a correct mesothelioma diagnosis is particularly difficult for doctors because the disease often presents with symptoms that mimic other common ailments. There is currently no known cure for mesothelioma, but treatments such as surgery and chemotherapy can help to improve the typical mesothelioma prognosis and even increase one's life expectancy.
Three major types of mesothelioma exist and they are differentiated by the organs primarily affected. Pleural mesothelioma (affecting the lung’s protective lining in the chest cavity) represents about three-quarters of all mesothelioma incidence. Peritoneal mesothelioma, which affects the abdominal cavity, and pericardial mesothelioma, which affects the cardiac cavity, comprise the remainder.
There are three recognized mesothelioma cell types. Between 50% and 70% of all mesotheliomas are of the epithelial variety. While prognosis is generally poor, it is considered less aggressive than sarcomatoid mesothelioma and biphasic mesothelioma, which comprise the remainder of cell-type diagnoses.
The cavities within the body encompassing the chest, abdomen, and heart are surrounded by a membrane of cells known as the mesothelium. Mesothelial cells assist in general organ functions. The mesothelium is particularly important to organs that are commonly in motion, such as expansion or contraction of the lungs, stomach, or heart. Lubrication from the mesothelial cells allows free range of motion within the body. The mesothelium of the chest, abdomen, and cardiac cavity are called the pleura, the peritoneum, and the pericardium, respectively. Each of these groupings of mesothelial cells is extremely critical to the functions of the body structures which they encompass.
Malignancies (cancerous tumors) occurring within the mesothelial membranes are known as malignant mesothelioma, or simply mesothelioma. Benign tumors of the mesothelium are known to occur, but are much more rare than malignant mesothelial tumors.
While tumors of the mesothelium were first recognized in the late 18th century, it was not until the middle of the 20th century that this particular cancer was studied and examined with more detail. It was at this time when suspicions of the cancer’s causal relationship with asbestos exposure became more substantiated. A joint research venture through the Department of Thoracic Surgery at the University of the Witswater and Johannesburg General Hospital in South Africa provided the most compelling evidence of the nexus between asbestos exposure and the development of pleural mesothelioma.
Incidence of mesothelioma is still quite rare, with only 2,500-3,000 diagnoses in the United States each year. There was a spike in reported diagnoses between 1970 and 1984, which has been attributed to the latency period between diagnosis and the height of industrial exposures, which occurred roughly 40-60 years prior to this time. While exposure was common across the United States in nearly all industries, it was particularly prevalent in the WWII-era military industrial cycle, including navy shipyards.
Although this cancer is much more common in men over the age of 60, mesothelioma in women and children has been documented as well. Mesothelioma causes for diagnosis in women and children are mainly attributed to secondary exposure to asbestos, as it was not uncommon for men to bring asbestos back into the home on their bodies or clothing.
Mesothelioma is diagnosed through a comprehensive combination of biopsy and imaging scans.
Mesothelioma can be a difficult malignancy to diagnose because the symptoms of the disease closely resemble other respiratory conditions, and because the pathology can be very difficult to distinguish from adenocarcinoma of the lung. For these reasons, misdiagnosis is not uncommon in mesothelioma patients. Symptoms of mesothelioma include chest pain, chronic cough, effusions of the chest and abdomen, and the presence of blood in lung fluid.
Diagnostic surgeries, including a biopsy, will typically be required to determine the type of malignant cells that are present in the body. Typically a body imaging scan, including a magnetic resonance image (MRI), computer topography (CT scan), and/or positron emission tomography (PET), will be required to determine the extent and location of the disease. Given how rare mesothelioma is, a formal staging classification exists only for pleural mesothelioma.
While mesothelioma is typically advanced at diagnosis, treatment options are available.
Mesothelioma, while certainly an aggressive disease, is a manageable malignancy. While there is no cure for the cancer, mesothelioma treatment options may potentially include surgery, chemotherapy, and radiation therapy. A combination of Alimta® and cisplatin is currently the only FDA-approved chemotherapy regimen, though several clinical trials are currently in progress utilizing other drugs including gemcitabine and Onconase®, that may lead to new treatment options that provide a benefit for patients.
Radiation therapy is also utilized, but typically in conjunction with other treatment methods like surgery and chemotherapy. Surgical resection of mesothelioma is possible in early-stage-diagnosed patients. Diagnostic and palliative procedures such as thoracentesis and pleurodesis are also commonly performed in patients with malignant mesothelioma in order to minimize cancer-related symptoms. Alternative therapies have also been used effectively by many mesothelioma patients to assist in managing symptoms of the disease and conventional treatments.Top Mesothelioma Surgeons in the Country
Mesothelioma is caused by exposure to asbestos.
Mesothelioma is primarily caused by exposure to asbestos, though cases have been documented in children or other individuals with no asbestos history. Asbestos is a microscopic and naturally-occurring mineral that lodges in the pleural lining of the lungs and the peritoneal lining of the abdominal cavity. In most cases, several years will pass (up to 60) before mesothelioma develops in those who have been exposed to asbestos.
In many cases, those individuals diagnosed with mesothelioma that have been known to be exposed to asbestos may be eligible for financial compensation from asbestos manufacturers for their illness. Medical treatment costs can be significant with a mesothelioma diagnosis. However, financial assistance is available to help offset those costs for those diagnosed with mesothelioma that were exposed to asbestos.
National Cancer Institute – Malignant Mesothelioma
Wagner, J.C., Sleggs, C.A., and Marchand, Paul. “Diffuse Pleural Mesothelioma and Asbestos Exposure in the North Western Cape Province.” Department of Thoracic Surgery: University of The Witswatersrand. Johannesburg, South Africa. 1960.
Grondin, Sean C., Sugarbaker, David J. “Pleuropneumonectomy in the Treatment of Malignant Pleural Mesothelioma” Chest December 1999 116:suppl 3 450S-454S;
Rusch, Valerie W. “Indications for pneumoctomy. Extrapleural pneumonectomy”
Roggli VL, Sharma A, Butnor KJ, Sporn T, Vollmer RT (2002). "Malignant mesothelioma and occupational exposure to asbestos: a clinicopathological correlation of 1445 cases". Ultrastruct Pathol 26(2): 55–65.
Brigham and Women’s Hospital – International Mesothelioma Program