According to the multivariate analysis, the CEA clearance pattern was independent predictive factor for tumor downstaging [Odds ratio (OR), 8.25; 95% CI 2.19–31.10; P = 0.002; Table 5) and pCR (OR, 8.30; 95% CI, 1.56–44.17; P = 0.013) (Table 6). Here, CEACAM5 is linked to neoplasm.