Abstract: Objective： To explore the association between hypoxia-inducible factor 1α (HIF-1α) expression and lymph node metastasis in oral squamous cell carcinoma (OSCC). Methods: Tumor specimens from 125 patients with histologically-proven, surgically-treated OSCC were examined by immunohistochemical staining for expression of HIF-1α. The patients were divided into two groups by the expression of HIF-1α, high expression of HIF-1α group (H-group) and low expression of HIF-1α group (L-group). The main assessment parameters were lymph node metastasis rate and disease-specific survival (DSS). The lymph node metastasis rate and clinicopathologic features were compared using Mann-Whitney test. The Kaplan-Meier curve was generated for each group and compared using the log-rank test. Cox proportional hazard models were utilized for multivariate analyses of HIF-1α expression and other baseline factors with DSS. All calculations and analyses were performed using the SPSS 17.0 software package. Results: The protein expression levels of HIF-1α were up-regulated in OSCC and two patients were unable to evaluate. There were 48 patients in L-group and 75 patients in H-group. Lymph node metastasis rate was 37.5% (18/48) for L-group and 58.7% (44/75) for H-group (P=0.027). Expression of HIF-1α was significantly correlated with lymph node metastasis. The patients of L-group had a significantly better DSS than the patients of Hgroup (70.8% vs. 46.7%, P=0.005), while the patients of L-group had a significantly better disease-free survival (DFS ) than the patients of H-group (60.4% vs. 36.0%, P=0.009) by Kaplan-Meier method. A multivariate survival analysis also showed that HIF-1α expression (HR=2.164, 95%CI: 1.150-4.074, P=0.017) and Tstage (HR=1.387, 95%CI: 1.066-1.804, P=0.015) both were the independent factors associated with prognosis. Conclusion: HIF-1α expression is significantly correlated with lymph node metastasis in OSCC. HIF-1α expression is an independent predictive factor for prognosis of OSCC patients, and may serve as a potential biomarker for molecular diagnosis and targeted therapy in future.

Key words: Hypoxia-inducible factor 1α, Carcinoma, squamous cell, Head and neck neoplasms, Lymphatic metastasis, Prognosis