HIF-1alpha mRNA is not associated with histopathological regression following neoadjuvant chemoradiation in esophageal cancer

Hypoxia-inducible factor-1alpha (HIF-1alpha) expression was reported to be associated with tumor growth, progression and resistance to radio-/chemotherapy. Whether HIF-1alpha mRNA or protein expression is associated with histomorphological response or prognosis following neoadjuvant chemoradiation and surgery in resectable, locally-advanced esophageal cancer was analyzed. Fifty-three patients received neoadjuvant chemoradiation (cisplatin, 5-fluorouracil, 36 Gy) followed by transthoracic en bloc esophagectomy. HIF-1alpha mRNA and protein expressions were analyzed by quantitative RT-PCR and immunostaining. In squamous cell carcinoma, HIF-1alpha mRNA expression was significantly higher than in paired normal epithelium (p < 0.001). Normal squamous epithelium showed significant elevated expression in adenocarcinomas, suggesting a field effect (p < 0.04). HIF-1alpha protein expression showed a significant regulation following chemoradiation. Neither HIF-1alpha mRNA nor protein expression was associated with histomorphological regression or prognosis. HIF-1alpha mRNA expression is differentially upregulated in esophageal squamous cell carcinoma compared to adenocarcinomas, but does not predict tumor regression or prognosis.