As shown in Figure 2, positive DNMT1 expression was significantly associated with poor overall survival (the median overall survival time: 11.6 months for positive vs. 8.2 months for negative), a high TNM stage, poor differentiation, lymph node metastasis and serum CEA (Additional file 1: Table S4). This evidence concerns the gene DNMT1 and metastatic malignant neoplasm in the lymph nodes.