Impact of primary tumor location on survival following colorectal liver metastases resection

Abstract

Background: Despite recent studies suggest that, among patients operated on for colorectal liver metastases (CLM), the primary tumor location (right versus left colon) may impact on postoperative survivals, Results are still contrasting. Objective: To evaluate survivals (overall(OS) and disease-free(DFS)) following liver resection of CLM from Right colon Cancer(RcC-CLM) versus Left colon Cancer(LcC-CLM), among patients undergoing preoperative chemotherapy. Methods: Among 727 patients operated on for CLM(1989-2016), following exclusion of patients with primary tumor located in the transverse colon or rectum and of patients not receving preoperative chemotherapy, 297 patients were identified. Among them, 81 operated for RcC-CLM were matched 1:1 with 81 operated for LcC-CLM, according to CLM number and diameter, disease-free interval(DFI) between primary tumor and CLM diagnosis, tumor N-status, and the presence of extrahepatic disease. Results: Overall, 66.7% of patients had multiple CLM, 21% had CLM>5 cm, 82.7% had DFI<12 months, 67.9% had N+ primary tumor, and 11.1% had extrahepatic disease at time of hepatectomy. RcC-CLM patients were similar to LcC-CLM in terms of demographic, clinical, perioperative, and pathologic characteristics. Patients operated for RcC-CLM, compared to LcC-CLM, had significantly shorter 5y-DFS(18% versus 39%) and 5y-OS(38% vs 65%). At multivariate analysis, being operated for RcC-CLM, compared to LcC-CLM, was the strongest predictor of recurrence(Hazard Ratio:2.265,p<.001) and death(HR:2.234,p=.001). In case of recurrence, recurrent disease resection was less frequent among RcC-CLM(26%), compared to LcC-CLM (44%,p=.05) and was associated with longer 5y-OS(64% vs 17%;p<.001). Conclusions: RcC-CLM, compared to LcC-CLM, are associated with worse survivals, probably related to a different pattern of recurrence precluding recurrence resection among RcC-CLM patients.