Surgical approach to pleural diffuse mesothelioma in Japan

The current status of the surgical treatment of patients with pleural diffuse mesothelioma in Japan was surveyed from the results of a questionnaire sent to members of The Japanese Association for Chest Surgery. Physicians at 57 institutions returned the questionnaire, and a total of 189 surgical cases of diffuse mesothelioma between 1987 and 1996 were analyzed. The age of the patients ranged between 18 and 80 years. They consisted of 154 males and 33 females (the gender of two patients was not indicated). By histological type, 104 cases had the epithelial type, 29 cases had the sarcomatous type, and 46 cases had the mixed type of diffuse mesothelioma (the histology of 10 patients was not indicated). As to the type of surgery, pleuropneumonectomy was performed in 116 cases (61%), and limited resection [including decortication (5 cases) and tumorectomy (68 cases)] was performed in 73 cases (39%). The goal of pleuropneumonectomy is radical resection of the tumor, which often requires combined resection of adjacent structures. The tumor was completely removed macroscopically in 84 (72%) of the 116 cases who underwent pleuropneumonectomy; however, among those with an epithelial-type tumor that was completely removed by pleuropneumonectomy, the tumor recurred postoperatively in 43% of these patients. Perioperative adjuvant therapy was performed in 83 of the 116 patients who underwent pleuropneumonectomy. The 2-year and 5-year survival rates of those who had undergone pleuropneumonectomy were 29.7 and 9.1%, respectively, and the perioperative mortality rate of this procedure was 6%. Limited resection, on the other hand, did not involve radical resection of the tumor. The 2-year and 5-year survival rates of the patients who had undergone limited resection were 26.1 and 9.5%, respectively, and the perioperative mortality rate was 6%. The survival rates and perioperative mortality rate of the patients who had undergone pleuropneumonectomy or limited resection did not significantly differ. The prognostic factors for survival included gender (P=0.0019) and adjuvant therapy (P=0.0034) by Cox's Regression Analysis. The goals of surgical treatment of pleural diffuse mesothelioma are relief of symptoms and prolongation of survival time. Selecting the appropriate surgical procedure and more effective adjuvant therapy for each particular case is necessary under a new, accurate staging system for diffuse mesothelioma.