Prognostic indicators for patients undergoing cytoreductive surgery and perioperative intraperitoneal chemotherapy for diffuse malignant peritoneal mesothelioma.

Abstract

This study evaluates clinical, radiological and histopathological prognostic indicators for survival of patients undergoing cytoreductive surgery and perioperative intraperitoneal chemotherapy for diffuse malignant peritoneal mesothelioma (DMPM). Sixty-two consecutive patients with DMPM underwent cytoreduction and perioperative intraperitoneal chemotherapy at the Washington Cancer Institute. Twenty-six clinical, radiological and histopathological parameters were analyzed in univariate and multivariate analyses using overall survival as an endpoint. The overall survival was 79 months (range 1-143 months), with 1-, 3- and 5-year survival rates of 84%, 58% and 50%, respectively. The following 14 prognostic variables were significant for survival in the univariate analysis: gender (P = .045), peritoneal cancer index (P = .038), completeness of cytoreduction score (P = .010), interpretive CT findings of the small bowel and mesentery (P = .001), mesothelioma cell type (P < .001), mesothelioma nuclear size (P < .001), nuclear/cytoplasmic ratio (P < .001), mitotic count (P < .001), atypical mitosis (P < .001), chromatin pattern (P < .001), cellular necrosis (P < .001), perineural invasion (P = .037), stroma pattern (P < .001) and depth of invasion (P = .014). In the multivariate analysis, the only factor that was independently associated with an improved survival after cytoreduction and perioperative intraperitoneal chemotherapy was mesothelioma nuclear size. Mesothelioma nuclear size was the dominant factor determining overall survival in patients with DMPM. A histopathological staging system based on measurement of the nuclear size was proposed.