Similarly, the adverse prognostic factors for RFS included large tumor size (HR = 1.437, P < 0.001), presence of lymph node metastasis (HR = 1.717, P < 0.001) and vascular invasion (HR = 1.400, P < 0.001), advanced TNM stage (HR = 1.652, P < 0.001; HR = 2.697, P < 0.001), poor tumor differentiation (HR = 1.405, P < 0.001), presence of preoperative obstructive jaundice (HR = 1.215, P = 0.027), elevated preoperative serum CA19‐9 (HR = 1.500, P < 0.001), high level of ALT (HR = 1.251, P = 0.006), high level of AST (HR = 1.258, P = 0.008), and high level of GGT (HR = 1.393, P < 0.001) (Table 3). This evidence concerns the gene GGT1 and neoplasm.