CEACAM5 and breast cancer: The false negative patients (38 patients of 197 total patients; 19.3%) determined by both cut-off values of CA15-3 (29.8227 U/mL) and CEA (8.28 ng/mL) were depicted in region “a” shown in Figure 5C. Figure 5C showed no correlation between the patients (Pearson r = 0.02728; P = 0.7029), suggesting both markers are sustained in the serum of patients with breast cancer in quite different manners and suggesting the combined use of CEA with CA15-3 is effective for screening the patients with breast cancer.