Abstract: Malignant pleural mesothelioma (MPM) is a deadly disease that produces a significant worldwide health care burden. The majority of cases are associated with prior asbestos exposure, but recent studies have identified a possible genetic predisposition in a minority of patients. Historically, obtaining a pathologic diagnosis of MPM was challenging, but with current pathological techniques, a secure diagnosis is possible in the majority of patients. Curative therapy for MPM remains elusive, and the primary treatment option for fit patients is platinum-based chemotherapy. Encouraging recent reports suggest that there may be a benefit to the addition of bevacizumab to standard chemotherapy as well as with the use of immune checkpoint inhibitors in MPM. Selected patients may be considered for aggressive surgical approaches, but there is considerable controversy regarding the true benefit of surgery and multimodality therapy in this disease.
Keywords: mesothelioma, asbestos, chemotherapy, surgery
Malignant pleural mesothelioma (MPM) is a rare and aggressive malignancy arising from the mesothelial cells lining the pleural cavity. There is a clear association between occupational or environmental asbestos and mineral fiber exposure and the development of MPM. An exposure is identified in up to 80% of cases. The latency period from exposure to development of disease can range from 20 to 70 years and appears to be dose dependent with heavily exposed patients presenting earlier.1 Ionizing radiation has also been implicated as a risk factor for MPM. Population studies show an increased risk of MPM in patients exposed to mediastinal irradiation for treatment of prior lymphoma as well as those exposed to occupational radiation. Patients with MPM associated with therapeutic irradiation for lymphoma typically present at a younger age and have longer overall survival compared to those with asbestos-associated MPM.2,3
The incidence of MPM began to rise in the USA in 1975 and peaked in 1995 coinciding with diminishing occupational asbestos exposure.4 Currently, there are an estimated 2,500 new cases in the USA annually. MPM is a disease of elderly males with an average age at diagnosis of 74 years and 80% of cases occurring in men. The incidence in females is fourfold lower and has remained mostly unchanged over the past 4 decades. In Europe, Australia, and Japan, the projected peak incidence will be between 2015 and 2025. The rising incidence worldwide is expected to result in substantial health and economic burden.5,6