No significant differences were found in CEA levels, CA 19–9, lymph node metastasis, vessel invasion, neural invasion, histology, and postoperative complication (P ≥ 0.05 in the fixed effects model or P ≥ 0.1 in the random effects model) (Table 2). The gene discussed is CEACAM5; the disease is metastatic malignant neoplasm in the lymph nodes.