Expression of hypoxia-inducible factors is correlated with the presence of a fibrotic focus and angiogenesis in pancreatic ductal adenocarcinomas.
Couvelard A., O'Toole D., Leek R., Turley H., Sauvanet A., Degott C., Ruszniewski P., Belghiti J., Harris AL., Gatter K., Pezzella F.
AIMS: To study the expression of hypoxia-regulated markers in pancreatic ductal adenocarcinomas (PA) in relationship to the presence of a fibrotic focus, angiogenesis quantification and clinical outcome. METHODS AND RESULTS: The expression of hypoxia-inducible factor (HIF)-1alpha, HIF-2alpha, carbonic anhydrase 9 (CA9) and vascular endothelial growth factor (VEGF) was immunohistochemically detected in 50 PA and correlated with tumour characteristics, microvascular density (MVD) and survival. HIF-1alpha was expressed within tumour cells in 68%, HIF-2alpha in 46%, CA9 in 78% and VEGF in 52% of the cases. Stromal expression was also noted for HIF-2alpha and CA9 in, respectively, 42% and 48% of the cases. Tumour CA9 expression was associated with that of VEGF (P=0.004) and that of stromal HIF-2alpha (P=0.013), with the presence of a fibrotic focus (P=0.046) and with an increased MVD (P=0.034). Tumour VEGF expression correlated with the presence of a fibrotic focus (P=0.039) and a greater MVD (P=0.047). Both the presence of a fibrotic focus (P=0.0002) and high tumour CA9 expression (P=0.029) were associated with reduced overall survival. CONCLUSION: The strong association of the presence of a fibrotic focus with CA9 expression and lower survival demonstrates that hypoxia-driven angiogenesis plays an important role in the progression of PA.