Risk Factors for Unresectable Recurrence After Up-Front Surgery for Colorectal Liver Metastasis.

BACKGROUND: There is no clear evidence that preoperative chemotherapy for resectable colorectal liver metastasis (CRLM) is superior to up-front surgery (UFS). The aim of this study was to identify the risk factors associated with poor prognosis after UFS for CRLM.

METHODS: Data about consecutive patients with CRLM who underwent liver resection at Nara Medical University Hospital between January 2000 and December 2015 were retrieved from a prospective database. Recurrence that developed within 2 years after liver resection and could not be surgically resected was defined as unresectable recurrence (UR). Preoperative risk factors associated with UR after UFS were analyzed. Among the patients with the identified risk factors, the patients who were treated with UFS were compared with those who received preoperative chemotherapy via propensity score-matching analysis.

RESULTS: There were 167 patients treated with UFS, and 71 of them developed UR (the UR group). The overall survival (OS) rate of the UR group was significantly worse than that of the non-UR group (5-year survival rate: 3.8 vs. 66.8%, p < 0.001). Multivariate analysis identified a primary colorectal cancer N factor of N2-3 as a risk factor for UR (hazard ratio 2.72, p = 0.004). Propensity score-matching analysis demonstrated that among patients with N2-3 primary colorectal cancer the post-initial treatment OS of the patients treated with UFS was significantly worse than that of the patients who received preoperative chemotherapy (5-year survival rate: 11.1 vs. 30.0%, p = 0.046).

CONCLUSIONS: Patients with CRLM with a primary colorectal cancer N factor of N2-3 should be considered for preoperative chemotherapy.