CEACAM5 and neoplasm: The Cox regression model was used to test whether the watch-and-wait strategy was associated with more distant metastasis, using T stage, N stage, CEA level, location of the tumor and regime of chemotherapy (oxaliplatin added or not) as covariates, and the difference was non-significant (HR 0.741, 95% CI 0.295–1.866, P = 0.525).