Poor outcome after cytoreductive surgery and HIPEC for colorectal peritoneal carcinomatosis with signet ring cell histology.

BACKGROUND: Signet ring cell cancer (SRCC) patients have a poor oncologic outcome. The aim of this study was to determine whether the potential drawbacks of hyperthermic intraperitoneal chemotherapy (HIPEC) outweigh the benefits in patients with peritoneally metastasized SRCC.

METHODS: Patients with peritoneal carcinomatosis (PC) of colorectal origin referred to two tertiary centers between April 2005 and December 2013 were identified and retrospectively analyzed. Data were compared between SRCC histology and other differentiations.

RESULTS: Three-hundred-fifty-one patients were referred for CRS+HIPEC among which 20 (5.7%) patients were identified with SRCC histology. CRS + HIPEC was performed in 16 of these 20 (80%) and 252 out of the 331 remaining patients (76.1%). A higher proportion of patients in the SRCC-group were diagnosed with N2 stage (62.5% vs. 36.1%, P=0.04). A macroscopic complete resection was achieved in 87.5% and 97.2% respectively (P=0.04). Median survival was 14.1 months compared to 35.1 months (P<0.01). Recurrence occurred in 68.8% of the SRCC patients and in 43.7% of the other histology patients (P=0.05).

CONCLUSION: Patients with SRCC and PC treated with CRS+HIPEC have a poor median survival only slightly reaching over 1 year. In the presence of other relative contraindications, SRCC histology should refrain a surgeon from performing CRS and HIPEC.