CEACAM5 and neoplasm: When considering the C model generated from the selected clinical baseline characteristics alone (pre-treatment CEA levels, MRI-T stage, and tumour histologic grade), the mean AUCs of 0.7053(95% confidence interval [CI], 0.6667–0.7440) in the training set and 0.6103(95% CI, 0.5983–0.6286) in the validation set (Fig. 2a) were obtained.