A tumor with a very serious prognosis, mesotheliomas are primary neoplasms that arise from either the pleura surrounding the lung or the peritoneum. Most mesotheliomas are diffuse and malignant, while a minority (less than 25 percent) are localized and benign in activity. It’s important to recognize these growths as they have serious and rapid progressions when diagnosed in many cases.
Mesotheliomas are usually tumors of men, and are strongly associated with exposure to asbestos. Up to 10 percent of workers with asbestos exposure through work may develop this disease over their lifetime, and almost three-quarters of mesothelioma development can be traced back to exposure to asbestos. There is a slow insidious course to cancer development—the period of exposure can range from 20 to over 40 years previous. Asbestos workers have a significant risk of developing lung cancer, especially when coupled with a smoking history, but there is not a correlation in itself between smoking and mesothelioma.
Generally, the first sign of mesothelioma is shortness of breath. There is generally about a 2-3-month lag before the symptoms are evaluated and the cause is pinpointed. Weight loss and chest pain accompany the shortness of breath, and many times the initial screening is for suspected lung cancer. Mesothelioma is not a disease of the young; in fact most cases are diagnosed right around the age of 70.
A chest x-ray is generally the first test on suspicion, and shows irregular, nodular thickening generally on one side of the chest. There is often a collection of fluid (pleural effusion) that is outlined. A CT scan is then done to differentiate benign from malignant disease, and which cases may benefit from early surgery. Fluid is removed from the effusion space, is usually bloody, and helps to confirm the diagnosis and differentiate it from lung cancer which is actually the more common investigative outcome. Special stains are done and microscopy is often definitive at this stage.
If the tumor is found to be benign, extensive surgery is done. The pleura is stripped and removed and sometimes the entire lung is removed depending on the extent and position of the growth. Newer trials also combine chemotherapy as part of the treatment in some individuals. In malignant tumors, the prognosis is more dire and surgery is not considered. Questions still exist on the best way to treat such cases, whether strong chemotherapeutic agents are used individually or more rarely combined with surgery if the growth is not widespread. At times the treatment is only symptomatic as there is no cure that can be expected.
The prognosis of malignant mesothelioma is grim—survival after diagnosis despite the most aggressive treatments is generally between 6 and 18 months. Five-year survival of such disease in such cases is well under 10 percent. Certain factors such as the microscopic appearance of the cells and results from plasma chemistries help to define prognosis. The usual cause of death in these cases is respiratory failure. Invasion of local structures by the tumor can be both painful and cause compression symptoms of other adjacent body organs.
Underwriting mesothelioma is very difficult and generally doesn’t have a favorable outcome. The disease must be benign to be considered, and a longer waiting period must pass to be sure the tumor does not grow, spread or have aggressive characteristics. Underlying lung cancer, particularly in ex-smokers, must be ruled out. Declining use of asbestos in construction materials will decrease the incidence of mesothelioma, but there is still a population at the target age group that is expected to suffer with this disease.
Robert Goldstone, MD, FACE, FLMI
MD, FACE, FLMI, board certified internist and endocrinologist, was most recently vice president and chief medical officer for Pacific Life and Pacific Life and Annuity. He has extensive brokerage and life insurance experience, having been medical director at both MetLife Brokerage and Transamerica Occidental Life. Goldstone is board certified in insurance medicine and the inaugural recipient of the W. John Elder Award for Insurance Medicine Journalism Excellence. He was also honored as a fellow of the prestigious American College of Endocrinology and has written monthly for Broker World since 1991. Goldstone does consulting full or part-time as well as on a fill-in basis for companies who need a medical director/physician. He can be reached by telephone at 949-943-2310. Emaill: firstname.lastname@example.org.