Abstract
The aim of this study was to examine correlation between low cytoplasmic expression of VPS33B and clinicopathologic features of renal cell carcinoma (RCC). In this study, ninety RCC patients ranging from years 2006 to 2012 were reviewed. VPS33B expression in tumor tissues and adjacent normal tissues was examined using immunohistochemistry (IHC) and association of VPS33B expression with RCC patient clinicopathologic parameters was evaluated. Final staining scores of 0-5 and 6-7 were respectively considered to be low and high expression. Immunohistochemical analysis confirmed that VPS33B protein expression was predominantly localized in cytoplasm of both RCC and adjacent normal tissues. Lower cytoplasmic VPS33B expression was observed in RCC compared to normal cells (P = 0.007). In addition, cytoplasmic VPS33B protein levels in tumor tissues were correlated with T stage (T1 vs. T2 vs. T3) (P = 0.038), stage (I-II vs. III-IV) (P = 0.035), and renal vein invasion (P = 0.039) of RCC patients. Lower RCC cytoplasmic VPS33B expression had a significantly shorter disease free survival (DFS) compared to the higher expression group (P = 0.030). Multivariate analysis suggested that low cytoplasmic VPS33B expression was an independent predictor for DFS of RCC patients. (P = 0.030). Our results suggest that low cytoplasmic VPS33B expression is a potential unfavorable prognostic factor for progression and prognosis of RCC.