The prognostic impact of resection margin status varies according to the genetic and morphological evaluation (GAME) score for colorectal liver metastasis.

ABSTRACT

BACKGROUND: Surgical margin status remains a controversial factor in predicting the outcome of colorectal liver metastases (CRLM) resection. Our study aims to evaluate the effects of surgical margins on oncologic outcomes with regard to the genetic and morphological evaluation (GAME) score. METHODS: R1 resection was defined as having a less than 1 mm margin width. Patients who underwent surgery for CRLM from January 2005 to December 2018 were recruited. The patients were divided into two risk subgroups, namely, the low or medium risk (GAME 0-3) and high-risk (GAME score 4 or more) groups. The effects of margin status on overall survival (OS) and recurrence-free survival rate (RFS) were examined. RESULTS: In total, 661 patients were recruited, among which 159 (24.1%) had R1 resection. Before hepatectomy, 514 patients showed a low or medium risk (R1 resection n = 124), while 147 patients demonstrated a high risk (R1 resection n = 35). In the whole cohort, multivariable analysis did show that R1 resection was associated with worse RFS and OS. While further research only found that in the low or medium risk group, R1 resection was related to poor OS and RFS. Meanwhile, in the high risk group, no significant difference was found in the median OS and RFS among patients with R0 or R1 resection. CONCLUSION: The prognostic role of margin status varied according to the GAME score. Margin clearance only improved survival rates in patients with low or medium GAME score. In contrast, R1 resection demonstrated similar oncologic outcomes with R0 resection in patients with high GAME score.