Hypoxia inducible factor-1α and vascular endothelial growth factor expression are associated with a poor prognosis in patients with nasopharyngeal carcinoma receiving radiotherapy with carbogen and nicotinamide

Aims: Hypoxia reduces tumour radiosensitivity and hypoxia inducible factor-1 alpha (HIF-1 alpha) plays an important role in this process. The aim of the study was to assess the prognostic impact of HIF-1 alpha. and vascular endothelial growth factor (VEGF) in patients with nasopharyngeal carcinoma who received radiation with hypoxia-modifying therapy (carbogen plus nicotinamide). Materials and methods: The immunohistochemical expression of HIF-1 alpha and VEGF was evaluated in nasopharyngeal carcinoma biopsies from 59 patients who received conventional radiotherapy combined with carbogen and nicotinamide. Results: A significant positive association was found between HIF-1 alpha and VEGF expression (P = 0.003). There was no association found between the level of HIF-1 alpha, VEGF expression and tumour stage, nodal stage, or clinical stage. Kaplan-Meier plots showed that positive HIF-1 alpha and VEGF expression were associated with a higher distant metastasis, a worse overall and disease-free survival, and the level of HIF-1 alpha and VEGF expression had no effect on locoregional recurrence. The multivariate analysis failed to confirm any association between HIF-1 alpha or VEGF and metastasis, disease-free or overall survival. Conclusions: These results suggest that the expression of hypoxia-associated markers (HIF-1 alpha and VEGF) may have prognostic significance in patients with nasopharyngeal carcinoma who receive radiation plus carbogen and nicotinamide, but further study is needed.