The incidence of malignant mesothelioma has increased greatly in the last 40 years. Current and recent past exposure to asbestos is expected to substantially increase this incidence. We report nine cases of malignant mesothelioma which temporarily responded to treatment with high-dose methotrexate-citrovorum rescue and vincristine. Further clinical trials of high-dose methotrexate with citrovorum rescue appear indicated in this disease.
Cancer 50:1245-1247, 1982.
H E REPORTED INCIDENCE Of mesothelioma has in-
T creased approximately tenfold during the last 40 years. There is strong evidence for an epidemiologic relationship between exposure to asbestos and the development of mes~thelioma.l-~ This tumor may be localized or diffuse and the benign or malignant characteristics are determined by the clinical picture. The histologic pattern has an inconsistent relationship to the progno~is.~ Most of the diffuse mesotheliomas are malignant and can arise from the pleura or p e r i t o n e ~m . ~. ~ A majority of the tumors appear to originate from the pleura, but abdominal involvement is seen more frequently than in the past.
The large scale expansion of the asbestos industry in the last forty years, with the wide spread use of asbestos products in construction materials, has led to more people exposed to asbestos than previously. Thus, the expectations for an increased incidence of this tumor in the future are quite realistic and there is a need to develop better diagnostic and treatment programs.* However, there are only limited reports concerning the local and systemic treatment of malignant mesothelioma generally providing pessimistic conclusions.9-' I
The treatment of malignant mesothelioma is complicated by the production of pleural or peritoneal fluid necessitating frequent thoracentesis or paracentesis. Therefore, an effective treatment would require appreciable entry of a drug into the corresponding cavity. There is ample evidence from experimental work that moderate and high doses of methotrexate (MTX) pen-From the