To the best of our knowledge, the predictive factors of preoperative lymph node metastasis are central tumor localization [19], larger tumor size [19,20,21], age ≤ 67 years [20], high CEA level [20,21], micropapillary-predominant adenocarcinoma [21,22,23], and consolidation/tumor ratio ≥ 89% [20]. Here, CEACAM5 is linked to adenocarcinoma.