CEACAM5 and cancer: In the clinical stage, the prognosis of the PCR-positive cancer was significantly poorer than the PCR-negative cancer in stage III (P=0.0004; Figure 3C) and stage IV (P=0.035; Figure 3D), while no significant difference in prognosis was found between the CEA and/or CK20 expression in stages I and II (data not shown).