After adjusting the multivariate Poisson model, the following variables were associated with the occurrence of a fragmented pattern of tumor regression: CEA levels > 5 ng/mL, downsizing < 50%, residual mucosal abnormality > 20 mm, and anatomopathologic lymph node involvement (ypN+) (P < 0.05) (Table 2). Here, CEACAM5 is linked to neoplasm.