The Preoperative AST/ALT (De Ritis) Ratio Represents a Poor Prognostic Factor in a Cohort of Patients with Nonmetastatic Renal Cell Carcinoma

Abstract

Aminotransaminases, which are strongly involved in cellular metabolism and cancer cell turnover, represent easily measureable, potential blood based biomarkers. We evaluated the prognostic value of the preoperatively assessed AST/ALT (De Ritis) ratio on clinically meaningful end points in a large European cohort of patients with nonmetastatic renal cell carcinoma. We retrospectively evaluated clinicopathological data on 698 patients with nonmetastatic renal cell carcinoma operated on between 2005 and 2013 at a single tertiary academic center. The potential prognostic value of the AST/ALT ratio was analyzed using the Kaplan-Meier method, and univariate and multivariate Cox proportional regression models. The impact of the ratio on the predictive accuracy of the Leibovich prognosis score was determined by the Harrell c-index. An increased (1.26 or greater) preoperative AST/ALT ratio was statistically significantly associated with several well established prognostic factors, including pathological T stage, as well as with histological tumor necrosis (p <0.05). On multivariate analysis an increased preoperative AST/ALT ratio was an independent prognostic factor for metastasis-free survival (HR 1.61, 95% CI 1.25-2.07, p <0.001) and overall survival (HR 1.76, 95% CI 1.34-2.32, p <0.001). The Harrell c-index was 0.77 using the Leibovich prognosis score and 0.81 when AST/ALT was added. In our study cohort with nonmetastatic renal cell carcinoma the preoperatively assessed AST/ALT ratio represented an independent prognostic factor. This ratio might further improve the predictive accuracy of well established prognosis scores.