Unexpectedly in our results, CEA mRNA in BC tissue specimens and CEA mRNA expression in both PB and tissue specimens were correlated significantly with grade I/II (Pearson chi-square = -3.91, p=0.048 and Pearson chi-square = -4.90, p=0.027, respectively), when analyzed between low and intermediate grades I/II and poorly differentiated histopathological grade III tumors. This evidence concerns the gene CEACAM5 and breast cancer.