Correlation of Caveolin-1 Expression on Tissue Microarray with Prognosis in Renal Cell Carcinoma

Abstract

Purpose: We investigated the relationship between the expression of caveolin-1, using a tissue microarray(TMA), and the prognosis of patients with renal cell carcinoma(RCC). Materials and Methods: TMA sections of formalin-fixed, paraffin-embedded tissues of RCC from 82 patients, who had undergone radical nephrectomy, were stained immunohistochemically with specific antibodies against caveolin-1. The caveolin-1 immunostaining was semi-quantitatively estimated based on intensity. The expression pattern of caveolin-1 was compared with the clinicopathological variables. Results: The expression of caveolin-1 was significantly correlated with tumor size(p=0.002), TNM stage(p＜0.001), T stage(p=0.001), M stage (p=0.004), grade(p=0.028) and metastasis(p＜0.001), and was also significantly higher in clear cell than non-clear cell RCC(p＜0.001). The survival of patients with higher caveolin-1 expression was significantly worse than that of patients with lower caveolin-1 expression(p=0.001). Univariate analyses were able to identify all variables, including caveolin-1 expression as significant prognostic factors for cancer-specific survival; multivariate analyses indicated that TNM stage, M stage and grade were independent prognostic factors. Caveolin-1 expression was not an independent factor. Conclusions: The increased expression of caveolin-1 is associated with tumor size, stage, grade, metastasis and a worse prognosis in RCC, which suggests that caveolin-1 may be important in the progression of RCC.