Abstract
Background/Aims: Previously rare malignant peritoneal mesothelioma appears to be increasing in incidence. We assessed the outcome of treatment for fatal malignant peritoneal mesothelioma cases in Japan Patients and methods: Among the 4,860 fatal mesothelioma cases extracted from the document “Vital Statistics of Japan” for 2003-2008, we obtained 805 cases from medical institutes with the permission of the families of the deceased and medical institutes. Among the 805 cases, we identified 114 cases with malignant peritoneal mesothelioma. Results: The 81 men and 33 women had a mean age of 64 years old. A past history of exposure to asbestos was confirmed in 61 of the 114 patients. A definitive diagnosis was obtained by open surgery and laparoscopy in 83 cases. Histologically 61 had epithelial, 10 biphasic, and 12 sarcomatoid mesothelioma. Chemotherapy had been conducted in 63, operation in 12, and chemotherapy + operation in 3. Overall median survival time was 4.8 months. With chemotherapy only, overall median survival time was 8.3 months. With operation, overall median survival was 4.7 months. In a multivariable analysis by the Cox proportional hazards model, age, gender, absence of abdominal pain, and histological type were prognostic factors. Chemotherapy and operation were not prognostic factors. Conclusion: There was a higher frequency of women and epithelial type in peritoneal mesothelioma than in pleural mesothelioma. Malignant peritoneal mesothelioma had lower populations of asbestos exposure, but an etiological relationship with highly concentrated asbestos exposure. Malignant peritoneal mesothelioma had a poor prognosis, and chemotherapy and operation were not found to be effective treatments based on this evaluation.
