What is Mesothelioma Cancer ?

Mesothelioma is an aggressive cancer affecting the membrane lining of the lungs and abdomen.

Malignant mesothelioma is the most serious of all asbestos-related diseases. The primary cause and risk factor for mesothelioma is exposure to asbestos.

Making a correct mesothelioma diagnosis is particularly difficult for doctors because the disease often presents with symptoms that mimic other common ailments. There is no known cure for mesothelioma, but treatments such as surgery and chemotherapy have helped to improve the typical mesothelioma prognosis.

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 surround 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 2,500-3000 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. Exposure was common in nearly all industries but was particularly common in the WWII-era military industrial cycle, including Navy Shipyards.

Although this cancer is much more common in men over the age of 60 (largely attributed to the industrial exposures within male-dominated industries), mesothelioma in women and children has been described 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 body or clothing if proper cleaning facilities were not available on site.

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 this reason, 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.

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.

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 had been exposed to asbestos.