Although the AUC for SLX was 0.710, which was higher than that for CEA (0.611, P = 0.227) or for CYFRA21-1 (0.507, P = 0.106), results of multivariate logistic regression analysis showed serum SLX concentration was an independent predictive factor for skip N2 in patients with c-stage IA NSCLC. Here, CEACAM5 is linked to non-small cell lung carcinoma.