Hypoxia-inducible factor 1α in breast cancer prognosis

• We quantitatively summarized 14 studies by means of meta-analysis.
• HIF-1α expression in patients with breast cancer has been clarified.
• High HIF-1α expression indicated a poor prognosis.

BackgroundRecent studies have assessed the relationship between hypoxia-inducible factor 1α (HIF-1α) expression and prognosis in breast cancer patients with inconsistent conclusions. To comprehensively and quantitatively summarize the evidence on the survival of patients with breast cancer, a meta-analysis was performed.MethodsSystematic literature searching was applied to the databases of PubMed, Embase and Web of science until April 1, 2013. Pooled HR with 95% CI was used to evaluate the association between HIF-1α expression and survival in breast cancer patients.ResultsFourteen papers including 2933 patients were subjected to the final analysis. Of these, 7 provided data on overall survival (OS), 8 on disease-free survival (DFS), 3 on distant metastasis-free survival (DMFS) and 3 on relapse-free survival (RFS). We observed that high expression of HIF-1α in breast cancer patients was an indicator of poor prognosis on OS (HR = 1.46, 95% CI: 1.12–1.92, P = 0.006), DFS (HR = 1.91, 95% CI: 1.43–2.57, P < 0.001), DMFS (HR = 2.17 95% CI: 1.16–4.05, P = 0.015) and RFS (HR = 1.33 95% CI: 1.09–1.61, P = 0.005). Significant heterogeneity was observed in the analyses of OS and DFS. Subgroup analyses by the cut-off value and antibody for IHC were conducted.ConclusionHigh expression of HIF-1α indicated a poor prognosis for patients with breast cancer.