Phase II studies: International registry of colorectal carcinomatosis.

Peritoneal carcinomatosis (PC) is a common manifestation of colorectal cancer and has traditionally been regarded as a terminal disease with a short median survival. Over the last decade, a new local-regional therapeutic approach combining cytoreductive surgery with perioperative intraperitoneal chemotherapy has evolved and promising survival results were reported in large phase II studies. A retrospective multicentric study of 506 patients from 28 institutions was performed to evaluate the international experience with this combined treatment and to identify the principal prognostic indicators. All patients had cytoreductive surgery and perioperative intraperitoneal chemotherapy (intraperitoneal chemohyperthermia and/or immediate postoperative intraperitoneal chemotherapy) within the 7 days following surgery. The morbidity and mortality rates were 22.9% and 4%, respectively. Patients in whom cytoreductive surgery was complete had a median survival of 32.4 months compared to 8.4 months for patients in whom complete cytoreductive surgery was not possible (p < 0.001). Positive independent prognostic indicators by multivariate analysis were complete cytoreduction, treatment by a second procedure, limited extent of PC, age less than 65 years, and use of adjuvant chemotherapy. The use of neoadjuvant chemotherapy, lymph node involvement, presence of liver metastasis and poor histological differentiation were negative independent prognostic indicators. The therapeutic approach combining cytoreductive surgery with perioperative intraperitoneal chemotherapy achieved long-term survival in carefully selected group of patients with PC from colorectal origin and offer a chance for cure or palliation in this condition. Further collaboration between peritoneal surface malignancy treatment centres are needed in order to standardize indications, intraperitoneal chemotherapy and peritonectomy techniques.