Surgical treatment for malignant pleural mesothelioma

We assessed the outcome of surgical treatment for malignant pleural mesothelioma (MPM) of dead cases in Japan and Okayama Rosai Hospital, and elucidated the surgical procedures. Among the 2,742 mesothelioma death cases extracted from the document ''Vital Statistics of Japan'' for 2003-2005, pathological diagnosis of MPM were obtained for 502 cases. We reviewed 94 cases (group I) undergoing surgery of 502 cases and 27 cases (group II) undergoing surgery of 91 cases in Okayama Rosai Hospital from April 1993 to September 2008. In group I, 88 men and 6 women had a mean age of 61 years old. According to staging of the International Mesothelioma Interest Group (IMIG) classification, 20 cases had stage I disease, 38 stage III and 26 unknown stages. Histological diagnosis was as follows: 44 cases were epithelial type, 22 cases sarcomatous type, and 28 cases unknown type. The 62 cases underwent extrapleural pneumonectomy (EPP), 6 cases pleurectomy/decortication (P/D), and 11 cases tumor resection (TR). In group II, 26 men and 1 woman had a mean age of 62 years old. In clinical stages, 17 cases had stage I disease, 6 stage II, and 4 stage III. Histological diagnosis was as follows: 16 cases were epithelial type, 9 cases sarcomatous type, and 2 cases biphasic type. All cases underwent EPP. For adjuvant therapy, 37 cases received no adjuvant therapy, 13 cases adjuvant chemotherapy, 5 cases preoperative chemotherapy, 3 cases adjuvant radiotherapy, 2 cases adjuvant chemotherapy and radiotherapy, and 2 cases intrapleural chemotherapy in group I. In group II, 13 cases received no adjuvant therapy, 10 cases adjuvant chemotherapy, 1 case preoperative chemotherapy, 1 case adjuvant radiotherapy, 1 case adjuvant chemotherapy and radiotherapy, and 1 case intrapleural chemotherapy. The median survival times (MST) was 13.2 months for EPP, 7.2 months for P/D, and 8.4 months for TR in group I. There were significant differences (EPP vs P/D: p=0.03, EPP vs TR: p=0.04) in survival rates between EPP and other surgical procedures. The MST was 13.2 months for EPP in group II. In a multivariable analysis by the Cox proportional hazards model, EPP was a prognostic factor in group I and II. EPP is an effective treatment for MPM. The establishment of the development of adjuvant therapy and more effective therapy are required for the improvement of survival in patients with MPM. (author)