After that, whether the following patient characteristics were risk factors for OS and RFS were investigated: age, sex, smoking history, drinking history, the first clinical symptom (abdominal pain and jaundice), diabetes mellitus, surgery procedure, CEA, CA19-9, radiologic tumour size, pathological stage (AJCC, 8th edition), differentiation degree, perineural invasion, pathological margin status, nodal involvement and the use of adjuvant chemotherapy. This evidence concerns the gene CEACAM5 and diabetes mellitus.