CEACAM5 and neoplasm: Serum carcinoembryonic antigen (CEA) greater than 5 μg/ml (P = 0.031), serum CA 19-9 greater than 37 U/ml (P = 0.002), tumor sizes greater than 2.5cm (P=0.002), and positive perineural invasion (P=0.003) were all associated with a poor prognosis in the histopathological subgroup.