Prognostic values of blood urea nitrogen/creatinine and cystatin C in patients with radical nephrectomy for renal cell carcinoma

Abstract

Background: To evaluate the prognostic value of blood urea nitrogen/creatinine ratio (BUN/SCr) and cystatin C (Cys C) in patients with renal cell carcinoma (RCC) after radical nephrectomy. Methods: The study analysed 348 patients with RCC who underwent radical nephrectomy. The optimal cut-off was obtained based on the ROC of specific survival outcomes and the maximum Youden index. The patients were divided into four groups: Group 1 (low BUN/SCr-low Cys C), Group 2 (low BUN/SCr-high Cys C), Group 3 (high BUN/SCr-low Cys C), and Group 4 (high BUN/SCr-high Cys C). The primary endpoint was cancer-specific survival (CSS), and the secondary endpoint was disease-free survival (DFS). Results: A strong positive correlation was shown between BUN/SCr value and Cys C level. Patients with a higher BUN/SCr ratio (17.41) and Cys C level (3.98 mg/L) had poorer survival outcomes. Notably, patients in group 4 showed the worst CSS and DFS rates, while patients in groups 1 and 2 had better survival outcomes with no significant difference between the two groups. A higher BUN/SCr ratio (17.41) and high Cys C serum level (3.98 mg/L) were independent predictors of CSS and DFS, in addition to preoperative tumour size and pathological T (pT) stage. Conclusion: This study provides the first evidence of the independent prognostic importance of BUN/SCr ratio and Cys C in patients with RCC after radical nephrectomy.

Keywords

• radical nephrectomy
• blood urea nitrogen
• creatinine
• cystatin c
• prognosis