Vascular cell adhesion molecule 1 predicts cancer-free survival in clear cell renal carcinoma patients

Purpose: Vascular cell adhesion molecule 1 (VCAM1) is a cell surface glycoprotein implicated in various pathophysiologic conditions. We measured VCAM1 expression levels in tumor tissues and evaluated its significance and prognostic use in renal cell carcinoma (RCC). Experimental Design: We used real-time quantitative PCR to examine the VCAM1 expression levels of a total of 485 sporadic renal tumors, including 429 clear cell, 21 papillary, 17 chromophobe, 11 oncocytomas, and 7 collecting duct carcinomas. We retrospectively examined the relationship of this expression to various clinicopathologic variables and the von Hippel-Lindau alteration status. We evaluated its significance with respect to patient survival rates using the Cox regression model combined with the split-sample method. Results: Compared with normal kidney samples (n = 43), VCAM1 was significantly up-regulated in clear cell RCC and papillary RCC, whereas it was down-regulated in chromophobe RCC and oncocytoma. In clear cell RCC, VCAM1 expression levels were apparently high in patients asymptomatic at presentation and in patients with small tumor size, low-stage, low-grade, microvascular invasion - negative, and von Hippel-Lindau alteration-positive tumors. Univariate analyses showed that VCAM1 high expression is strongly associated with better outcomes in clear cell and papillary RCCs. Further, Cox multivariate analysis models combined with the split-sample method revealed that this association is significant only in cancer-free survival for patients with clear cell RCC after curative surgical resection. Conclusions: VCAM1 expression levels were found to be histologically subtype specific in renal tumors. Determination of the VCAM1 expression level as a biomarker can provide useful prognostic information for patients with clear cell RCC.