ERCC6 and metastasis: Multivariate Cox model for PFS showed that rs2228528 genotype with the A allele in ERCC6 (HR 0.54; 95% CI, 0.37–0.78, p = 0.001) and surgical resection after FOLFIRINOX chemotherapy (HR 0.27; 95% CI, 0.14–0.52, p < 0.001) were independent predictors for better PFS, whereas metastasis stage M1 (HR 2.21; 95% CI, 1.16–4.21, p = 0.016) was an independent predictor for poor PFS (Table 2).