CEACAM5 and adenocarcinoma: Independent associated factors comprised adenocarcinoma histological type (RR 5.2; 95% CI, 1.002–29; p = 0.0002) and CEA serum levels ≥ 40 ng/mL (RR 11.4; 95% CI, 1.7–74; p < 0.001) (Table 2).