Epithelial-to-mesenchymal transition in human esophageal cancer associates with tumor progression and patient's survival.

The epithelial-mesenchymal transition (EMT) is an essential step in invasion and metastasis of human cancers. Identification of EMT status would help us to properly understand the mechanism of cancer metastasis and progression. In the present study, tissue microarray and immunohistochemical staining of two important markers, E-cadherin and Vimentin, were used to characterize the EMT status in human esophageal cancer. We selected the appropriate cut-off values of expression levels of E-cadherin and Vimentin, and found 63 out of 105 cases of esophageal cancers underwent EMT. And we also found that in the subgroup with (T₃ + T₄), the ratio of patients undergoing EMT was significantly higher than that in the subgroup with (T₁ + T₂) (P = 0.0097), and in the subgroup with metastasis, the ratio of patients undergoing EMT was significantly higher than that in the subgroup with no metastasis (P = 0.0253). The log-rank survival analysis showed that the overall survival rate of the patients undergoing EMT was significantly poorer than that of the patients with wide type status (P = 0.0278, HR = 2.470, 95% CI: 1.971~2.970). In the COX model analysis, we also found that the EMT status of the esophageal cancer patients could be used as an independent risk factor for the prediction of prognosis of this malignancy (P = 0.026, HR = 2.306, 95% CI: 1.103~4.824). Thus, our present study successfully established a method by using tissue microarray and the markers, E-cadherin and Vimentin, to conveniently and properly identify the EMT status in human esophageal cancer, and revealed that the EMT status significantly associated with invasion, metastasis and prognosis in this malignancy.