Critical analysis of 33 patients with peritoneal carcinomatosis secondary to colorectal and appendiceal signet ring cell carcinoma.

Primary signet-ring cell carcinoma (SRC) of colorectal and appendiceal origin is a rare entity with an aggressive biology and clinical behavior. The majority of patients develop peritoneal carcinomatosis (PC) early in the disease. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) may potentially improve survival. An observational study of 33 patients with SRC of colorectal or appendiceal origin was identified through a retrospective review of two peritoneal surface malignancy databases between January 1997 and December 2008. Survival analysis was performed using the Kaplan-Meier method. Thirty-three patients (18 women (55%); mean age at diagnosis of carcinomatosis, 49 (standard deviation = 12) years) were identified to have SRC, with 15 cases of colorectal and 18 of appendiceal origin. For patients with colonic SRC who underwent complete CRS and HIPEC versus systemic chemotherapy only, the median survival was 13 and 18 months (P = 0.75). For patients with appendiceal SRC who underwent complete CRS and HIPEC versus systemic chemotherapy only, the median survival was 27 and 15 months (P = 0.12). There seems to be less survival benefits after a complete CRS and HIPEC as a curative treatment for PC from colorectal SRC compared with that for non-SRC colorectal adenocarcinoma. However, in patients with appendiceal SRC, long-term survival is a reality after treatment.