Expression And Significance Of Vegfr-2 And Pdgfr-α In Pheochromocytomas/paragangliomas

[Objective]To study the expression of vascular endothelial growth factor receptor 2 (VEGFR-2) and platelet derived growth factorα(PDGFR-α) in benign pheochromocytomas, malignant pheochromocytomas and normal adrenomedullary tissue. To discuss the value in distinction between benign and malignant pheochromocytomas and the significance in the target therapy for malignant pheochromocytomas.[Methods]The expression of VEGFR-2 and PDGFR-αwas assessed in the 16 benign pheochromocytomas (group A),18 malignant pheochromocytomas (group B) and 6 normal adrenomedullary tissue (group C) by immunohistochemistry. The numbers of positive cells and degrees of expression of VEGFR-2 and PDGFR-a were observed and scored under high power lens for each group. Differentiation was analyzed by the Chi-Square test. Expression of VEGFR-2 and PDGFR-αwas compared between pheochromocytomas and paragangliomas, functional tumors and disfuctional tumors, major tumors and minor tumors, single tumors and multiple tumors, malignant primary tumors and metastatic lesions respectively.P value less than 0.05 was regarded as statistical significance. Data were analyzed by SPSS software.[Results]1,Expression of VEGFR-2 was observed in all pheochromocytomas/ paragangliomas. Most of benign tumors showed positive or mildly positive expression, and most of malignant tissue showed positive or strongly positive expression, and normal adrenomedullary tissue showed mildly positive or negative expression. There was significant difference between each group(P＜0.05). Expression of VEGFR-2 in pheochromocytomas was stronger than that in paragangliomas, and there was significant difference between each other (P＜0.05). There was no significant difference between functional tumors and disfuctional tumors, major tumors and minor tumors, single tumors and multiple tumors, malignant primary tumors and metastatic lesions respectively (P>0.05)2,Most of benign and malignant pheochromocytomas/paragangliomas and normal adrenomedullary tissue showed mildly positive or negative PDGFR-αexpression. There was no significant difference between each group (P>0.05). There was no significant difference between different sites of tumors, functional tumors and disfuctional tumors, major tumors and minor tumors, single tumors and multiple tumors, malignant primary tumors and metastatic lesions respectively (P>0.05)[Conclusion]1,The expression level of VEGFR-2 might be used as one marker to differentiate benign and malignant pheochromocytomas/paragangliomas. Up-regulation of VEGFR-2 might play an important role in the growth and development of malignant pheochromocytomas/paragangliomas. Thus, VEGFR-2 might be one of targets to treat malignant pheochromocytomas/ paragangliomas.2,PDGFR-αcan not be used as a marker to differentiate benign and malignant pheochromocytomas/paragangliomas. PDGFR-αmay not play an important role in the growth and development of pheochromocytomas/ paragangliomas. PDGFR-αmay not be one of targets to treat malignant pheochromocytomas/ paragangli omas.