The expression level of vascular endothelial growth factor receptor-2, vascular endothelial growth factor receptor-3, and insulin-like growth factor II mRNA binding protein 3 in renal cell carcinoma: Can these markers indicate poor prognosis in immunohistochemical examination?

Background: The malignant tumors of the kidney are the most aggressive among urologic cancers. To treat patients with renal cell carcinoma (RCC), it is important to understand the disease's prognostic factors. Angiogenesis is an essential process, responsible for the growing, and spreading of neoplastic tissues. Vascular endothelial growth factor (VEGF), the most potent angiogenetic factor known, and its receptor VEGF (VEGFR) play an important role in angiogenesis. Insulin-like growth factor-II mRNA binding protein 3 (IMP-3) is found in some malignant tumors and contributes to cell growth and cell migration during the early stages of embryogenesis. Material and Methods: The following study retrospectively evaluated 48 radical, 29 simple, and 23 partial nephrectomy specimens with RCC. Pathologic prognostic parameters, including tumor size, tumor stage, Fuhrman nuclear grade, distant metastasis status, and lymph node involvement status were compared with the immunohistochemical expression levels of VEGFR-2, VEGFR-3, and IMP-3. Results: Except the relation between VEGFR-3 and Fuhrman nuclear grade, there was no significant relation with the expressions of VEGFR-2, VEGFR-3, and IMP-3 and the pathologic prognostic parameters such as tumor size, tumor stage, Fuhrman nuclear grade, distant metastasis status, and lymph node involvement status. All three markers showed significant expression in almost all chromophobe and papillary histologic subtypes. The expression rates for chromophobe, papillary type 1, and type 2 RCC were 100%, 90%, and 100% for VEGFR-2, respectively, and 87.5%, 90%, and 100% for VEGFR-3, respectively. The expression rates of IMP-3 were 50% for papillary type 1, 83.3% for papillary type 2, and 100% for chromophobe RCC. Conclusion: Although the limited number of cases, current data gathered from our study shows that these markers have no relation with pathologic prognostic parameters and would not provide additional information in the immunohistochemical examination. Anyway, their tendency of expression in chromophobe and papillary type RCC is remarkable which should be evaluated with a larger number of cases.