[Malignant pleural mesothelioma]

Malignant pleural mesothelioma (MPM) used to be a rare disease, but is recently increasing in incidence. Most MPMs were thought to have a causal relationship with asbestos exposure. However, a DNA sequence similar to simian virus 40 has been detected in MPM tumor cells, which suggests a role of viral infection in its etiology. MPM predominantly afflicts men over 60 years old, with a male to female ratio of 3 to 1. MPM is a challenging disease in all aspects, including diagnosis, staging and treatment. Its diagnosis requires a panel of immunohistochemical stains. Multimodal treatment including surgery has shown significant benefit in highly selected patients. Most cytotoxic drugs administered as a single agent have been evaluated, but none have consistently demonstrated response rates greater than 20%. The combination of gemcitabine plus cisplatin has become a standard regimen, although there has been significant variability in response rates between studies. The novel antifolates pemetrexed and raltitrexed are promising agents and undergoing 3 phase III studies. One of these studies is the largest trial ever conducted in MPM patients, which randomized 456 patients into cisplatin with or without pemetrexed groups. The median survival time was 12.1 months in the cisplatin with pemetrexed arm and 9.3 months in the cisplatin alone arm (p = 0.02). Another of these studies is currently being conducted to compare cisplatin with or without raltitrexed. The third study is comparing pemetrexed alone to supportive care. The results of these trials are expected to define the role of chemotherapy for patients with MPM.