The preoperative serum cystatin-C as an independent prognostic factor for survival in upper tract urothelial carcinoma

Cystatin-C (Cys-C) has been reported as a valuable prognostic biomarker in various malignancies. However, its effect on upper tract urothelial carcinoma (UTUC) patients has not been investigated before. Thus, to explore the impact of Cys-C on survival outcomes in patients undergoing radical nephroureterectomy (RNU), a total of 538 patients with UTUC who underwent RNU between 2005 and 2014 in our center (West China Hospital, Chengdu, China) were included in this study. Kaplan–Meier method and Cox regression analyses were performed to assess the relationship between Cys-C and survival outcomes using SPSS version 22.0. The cutoff value of Cys-C was set as 1.4 mg l(−1) using the receiver operating characteristic (ROC) curves and Youden index. The mean age of patients included was 66.1 ± 11.1 years, and the median follow-up duration was 38 (interquartile range: 19–56) months. Overall, 162 (30.1%) patients had elevated Cys-C, and they were much older and had worse renal function than those with Cys-C <1.4 mg l(−1) (both P < 0.001). Meanwhile, Kaplan–Meier analysis revealed that the group with elevated Cys-C had worse cancer-specific survival (CSS, P = 0.001), disease recurrence-free survival (RFS, P = 0.003), and overall survival (OS, P < 0.001). Multivariable Cox analysis suggested that the elevated Cys-C was identified as an independent prognostic predictor of CSS (hazard ratio [HR]: 1.997, 95% confidential interval [CI]: 1.331–2.996), RFS (HR: 1.429, 95% CI: 1.009–2.023), and OS (HR: 1.989, 95% CI: 1.366–2.896). In conclusion, our result revealed that the elevated preoperative serum Cys-C was significantly associated with worse outcomes in UTUC patients undergoing RNU.