OBJECTIVETo investigate the expression of enhancer of zeste homolog 2 (EZH2) in esophageal squamous cell carcinoma and its association with the prognosis of postoperative patients.

METHODSSurgical specimens were obtained from 102 patients with esophageal squamous cell carcinoma undergoing radical resection in our hospital from 1996 to 2006. Immunochemistry was employed to examine EZH2 protein expressions in the specimens, including 102 carcinoma tissue specimens, 30 adjacent tissue specimens and 30 normal esophageal tissue specimens. The expression levels of EZH2 were analyzed in relation to the clinicopathological parameters of the patients including gender, age, tumor differentiation, TNM, and lymph node metastasis. The postoperative patients were followed up to analyze the association of EZH2 expression with the clinical outcomes.

RESULTSThe esophageal squamous cell carcinoma tissue showed a higher EZH2 expression than the adjacent and normal esophageal tissues. EZH2 expression was higher in poorly differentiated carcinoma than in well differentiated tissue, and also higher in cases with lymph node metastasis than those without; the expression was higher in TNM stage II/III patients than in stage I patients but lower than in stage IV patients. The patients with low EZH2 expression was found to have a longer survival time than those with high EZH2 expression (P<0.05).

CONCLUSIONEZH2 plays an important role in the differentiation and metastasis of esophageal squamous cell carcinoma, and a high EZH2 expression is associated with a poor outcome in the the postoperative patients.