CEACAM5 and neoplasm: The age, gender, body mass index, ASA score, tumor stage, tumor differentiation, tumor location, surgical procedure, chemotherapy regimen and radiation dose were not statistically different between the two groups.The pretreatment serum CEA level was significantly lower in the pCR group than in the non-pCR group (2.6 vs. 5.8 ng/mL, P=0.001).