CEACAM5 and malignant colon neoplasm: Considering the definite efficacy of ACT in T4 disease, we then assumed that the primary reason that the finding of our study was conflicted with previous researches (8, 9) which showed the survival benefit of ACT in stage II colon cancer with elevated serum CEA was because the studies did not exclusively focus on stage IIA colon cancer and their study cohorts were mixed with the subset of stage IIB (T4aN0M0) and IIC (T4bN0M0) colon cancers.