KRAS and neoplasm: Furthermore, the univariate analyses revealed that shorter OS duration in patients was associated with synchronous metastasis (P = 0.050), bilobar tumor distribution (P = 0.005), increased number of tumors (P = 0.001), large tumor size (≥ 5 cm, P < 0.001), high serum carcinoembryonic antigen levels (≥5 ng/mL, P = 0.029), major hepatectomy (P = 0.002), R1 resection (P = 0.002), and mutant KRAS (P = 0.026) (Table 2).