CEACAM5 and pancreatic ductal adenocarcinoma: Nakamura et al [12] reported that serum carcinoembryonic antigen (CEA) concentrations might also be used for assessment of treatment effect but not good for the differential diagnosis, because the presence of a high CEA concentration in patients with SCCP is variable (in our case, the serum CEA was normal) and CEA is not specific for SCCP but also frequently increases in patient with pancreatic ductal adenocarcinoma.