[Expression of erythropoietin receptor in esophageal carcinoma and its correlation to microvessel density]

Erythropoietin receptor (EPO-R) is expressed in many kinds of tumors. The EPO/EPO-R signaling is involved in tumor cell proliferation, angiogenesis, and invasion. This study was to detect the expression of EPO-R in esophageal carcinoma, and explore its correlation to angiogenesis.

The expression of EPO-R protein in 110 specimens of primary esophageal carcinoma was assessed by immunohistochemistry. The microvessels were immunohistochemically labeled with factor VIII-related antigen (FVIII-R Ag) to assess microvessel density (MVD).

EPO-R was detected in all tumor tissues. It was expressed in cytoplasm and/or on cell membrane. Up-regulated EPO-R expression was correlated to poor differentiation (P<0.001) and lymph node metastasis (P=0.006). Increased MVD was correlated to poor differentiation (P<0.001), lymph node metastasis (P<0.001), advanced stage (III/IVA/IVB) (P=0.022), and smoking (P=0.029). The expression of EPO-R was positively correlated to MVD (r=0.618, P<0.01).

EPO-R expressed generally in esophageal carcinoma. The level of EPO-R positively correlates to angiogenesis and progression of esophageal carcinoma. EPO might be an endogenous stimulant of angiogenesis during the progression of esophageal carcinoma.