Expression of podoplanin and vimentin is correlated with prognosis in esophageal squamous cell carcinoma

Podoplanin is a small membrane mucin, which is involved in cell migration and cancer cell invasion. However, the roles of podoplanin in esophageal squamous cell carcinoma (ESCC) are poorly understood. In the present study, 139 cases of surgically resected ESCC were analyzed and the clinicopathological significance of podoplanin membrane expression in ESCC was demonstrated. Podoplanin expression was positive in 66.2% (92/139) of ESCC samples; with weak expression in 32.4% (45/139), and strong expression in 33.8% (47/139). Membrane expression of podoplanin was significantly associated with tumor status (P=0.001), venous invasion (P=0.035) and Union for International Cancer Control stage (P=0.029). Patients who exhibited strong podoplanin expression, were shown to have a poorer prognosis [hazard ratio (HR), 3.949; 95% confidence interval (CI), 2.001–7.794]. Expression of vimentin, a mesenchymal marker, was detected in 49 cases (35.3%) and was associated with venous invasion (P=0.020). Vimentin-positive cases were also more likely to have a worse prognosis than vimentin-negative cases (HR, 2.161; 95% CI, 1.300–3.592). Podoplanin membrane expression was significantly correlated with vimentin cytoplasmic expression in ESCC (P<0.001). The present study confirmed that podo-planin and vimentin are independent predictors of mortality (HR, 3.084; 95% CI, 1.543–6.164). These results suggest that podoplanin membrane expression results in epithelial-mesenchymal transition and promotes aggressive invasion in human ESCC.