Expression of Endogenous Hypoxia Markers in Vulvar Squamous Cell Carcinoma

Objective: To investigate the expression of endogenous hypoxia-related markers identified as beinginvolved in vulvar squamous cell carcinoma (VSCC).
Methods: We performed immunohistochemical stainingof hypoxia-inducible factor-1α (HIF-1α), glucose transporter-1 (GLUT-1), carbonic anhydrase 9 (CA-9) andvascular endothelial growth factor (VEGF), on tissue sections of 25 VSCC patients, 10 vulvar intraepithelialneoplasia (VIN) patients and 12 healthy controls.
Results: HIF-1α expression was found in all sections, with nosignificant difference between controls, VIN and VSCC sections (all P<0.05). Glut-1 expression was found in25% of control, 90% of VIN and 100% of VSCC sections. A significant difference between control and VIN orVSCC was observed (all P<0.05), while no difference was found between VIN and VSCC sections (P>0.05). CA-9expression was negative in control sections, but it was found in 30% of VIN sections and 52% of VSCC sectionswith strong staining. Similarly, CA-9 expression also showed obvious differences between controls and VIN orVSCC sections (all P<0.05). However, there was no significant difference between VIN and VSCC (P>0.05).There were only 25% of control sections with weak VEGF expression, while strong staining was found in about60% of VIN sections and 25% of VSCC sections (all P<0.05). In addition, a difference was also found betweenVIN and VSCC sections (P<0.05).
Conclusion: Expression of endogenous hypoxia markers (HIF-1α, GLUT-1,CA-9 and VEGF) might be involved in the malignant progression of VSCC.