Protein expression of hypoxia-inducible factor-1 alpha and hepatocellular carcinoma: A systematic review with meta-analysis

SummaryPurposeTo investigate the relationship of protein expression of hypoxia-inducible factor-1 alpha (HIF-1α) with clinicopathological factors and prognosis of hepatocellular carcinoma (HCC).MethodsPubMed and Embase were searched from their inception through August 2013 for studies that reported the association between protein expression of HIF-1α and HCC. Random effects meta-analyses were used to summarize the odds ratios (ORs) and 95% confidence intervals (CIs).ResultsEight studies involving 851 patients with HCC were included. Protein expression level of HIF-1α was not found to be related with capsule formation, cirrhosis, tumor size, and tumor differentiation of HCC, except vascular invasion. The positive association between HIF-1α expression and vascular invasion of HCC was statistically significant (OR: 2.04, 95% CI: 1.31–3.18). As a prognostic factor, a high level of HIF-1α expression would be associated with a poor disease-free survival (OR: 2.10, 95% CI: 1.48–2.97).ConclusionHigher level of HIF-1α expression may indicate a bigger possibility of vascular invasion and a poorer prognosis of HCC.