De Ritis ratio (aspartate transaminase/alanine transaminase ratio) as a significant prognostic factor after surgical treatment in patients with clear-cell localized renal cell carcinoma: a propensity score-matched study.

Abstract

To evaluate the associations of preoperative De Ritis ratio (aspartate transaminase [AST]/alanine transaminase [ALT]) with postoperative clinical outcomes after surgical treatment of localized RCC. We retrospectively reviewed data from 2 965 patients surgically treated for non-metastatic RCC. Propensity scores for high AST/ALT ratio were calculated and 430 patients with a high AST/ALT ratio were matched to 1 117 patients with a low AST/ALT ratio. The association between AST/ALT ratio and postoperative outcomes was tested. Multivariate Cox analyses were performed to identify the independent predictors of progression-free (PFS), overall (OS) and cancer-specific survival (CSS). According to the receiver-operating curve of AST/ALT for cancer-specific mortality, we stratified the patients into two groups using a threshold of 1.5. Before matching, patients with a high AST/ALT ratio had worse PFS, OS and CSS (all P < 0.001). In the propensity score-matched cohort with 1 547 patients, patients with a high AST/ALT ratio had inferior PFS, OS and CSS outcomes (all P < 0.001). Multivariate analysis showed that a high AST/ALT ratio was an independent predictor of disease progression (hazard ratio [HR] 1.372, 95% CI 1.003-1.882; P = 0.048), overall mortality (HR 1.559, 95% CI 1.069-2.272; P = 0.021), and cancer-specific mortality (HR 1.974, 95% CI 1.250-3.118; P = 0.004). In a subgroup analysis according to tumour histology, high AST/ALT had a significant association with postoperative survival in clear-cell renal cell carcinoma (RCC), but not in non-clear-cell RCC. An elevated AST/ALT ratio was significantly associated with worse postoperative survival in patients surgically treated for localized clear-cell RCC. Further prospective studies are needed to understand the prognostic value of preoperative AST/ALT ratio.