Analysis of patient selection policy and pattern of recurrence after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for colorectal carcinomatosis.

BACKGROUND: Actual cure rate and patterns of recurrence after cytoreductive surgery (CRS) associated to hyperthermic intraperitoneal chemotherapy (HIPEC) for patients with colorectal peritoneal carcinomatosis (PC) are not yet well explored. Moreover, the selection policy to this resource-consuming treatment is still a matter of debate.

METHODS: From a dataset of 400 CRS+HIPEC performed between October 1996 and December 2015, we selected 54 consecutive patients with colorectal PC. Exclusion criteria were age>70, PS>2, or disease progression during chemotherapy. From 2004, we also excluded patients with both PCI>16 and poor prognostic factors of primary tumor (i.e. T4, N2 and G3) and only proceeded to HIPEC in case of optimal cytoreduction. Prognostic factors, cure rate and patterns of recurrence were investigated, comparing the two time periods.

RESULTS: After 2004, median overall survival was 52 months, with a 40% 5-year survival. Completeness of cytoreduction, primary tumor histology and time period were independent prognostic factors. Median recurrence-free survival was 16 months. A relapse was detected in 41 out of 46 patients with optimal cytoreduction. Main sites of first relapse were peritoneum (73%), and distant metastases (37%), mainly to liver and lungs. Peritoneal and liver/lung metastases presented as isolated recurrence in 73% and 58% of cases, respectively.

CONCLUSIONS: By a selection policy based on patient, disease extension and primary tumor factors, a median survival higher than 50 months can be expected. Most patients will eventually recur, mainly in the peritoneum. The pattern of recurrence suggests a potential role for more effective intraperitoneal therapies and repeat surgical treatments.