OBJECTIVETo explore the expression of hypoxia inducible factor-1α(HIF-1α) in esophageal squamous cell carcinoma and its correlation with clinicopathological features.

METHODSOriginal literatures in foreign languages regarding correlation between HIF-1α and esophageal squamous cell carcinoma were identified from Cochrane Library, PubMed, EMbase database, and Chinese original literatures were from CBM, CNKI. All analyses were performed by Stata 11.0 software. Histological grade, degree of differentiation, T stage, lymph node metastasis, tumor stage, lymphatic invasion and vascular invasion were analyzed using pooled odds ratio (OR) with 95% confidence interval (CI).

RESULTSA total of 14 studies including 1 121 patients were enrolled in this meta analysis. Comparing with normal tissue, the expression of HIF-1α in esophageal squamous cell carcinoma was significantly enhanced (OR = 0.088, 95% CI: 0.061-0.129, P = 0.000); HIF-1α was significantly associated with T stage and lymph node metastasis (OR = 0.421, 95% CI: 0.222-0.798, P = 0.008; OR = 0.387, 95% CI: 0.207-0.725, P = 0.003). High expression of HIF-1α was correlated with an increased depth of tumor invasion, more lymph node metastasis and advanced tumor stage, whereas there was no relation to the degree of differentiation, histological grade, tumor stage, lymphatic invasion and vascular invasion.

CONCLUSIONSHigh expression of HIF-1α protein correlates with an increased risk of esophageal squamous cell carcinoma. HIF-1α may be an indicator for T stage, lymph node metastasis and tumor stage, but further studies are needed.