BAI1 as a Prognostic Marker of Clear Cell Renal Cell Carcinoma (ccRCC)

Background/Aim: The treatment of advanced clear cell renal cell carcinoma (ccRCC) is based on stratification of patients according to prognosis (favorable, intermediate, and poor). The aim of the study was to improve prognostication by biomarkers involved in angiogenesis. Patients and Methods: The study group consisted of 20 patients who underwent surgery for ccRCC. Gene expression analysis was peformed on a set of matched (primary tumor, metastasis, n=20+20) FFPE tissue samples. An additional analysis was done on expression data of 606 patients obtained from the TCGA Kidney Clear Cell Carcinoma (KIRC) database. Quantitative estimation of mRNA of selected genes (TaqMan human Angiogenesis Array, 97 genes) was performed by a real-time RT-PCR method with TaqMan^® arrays. Results: Using the Cox regression model, 4 genes (PDGFB, FGF4, EPHB2 and BAI1) were identified whose expression was related to progression-free interval (PFI). Further analysis using the Kaplan Meier method conclusively revealed the relationship of BAI1 expression to prognosis (both datasets). Patients with higher BAI1 expression had significantly shorter PFI and overall survival. Conclusion: We showed that tumor tissue BAI1 expression level is a prognostic marker in ccRCC. Therefore, this gene might be involved in a prognostic panel to improve scoring systems on which the management of metastatic ccRCC patients is based.