Preoperative low plasma creatine kinase levels predict worse survival outcomes in bladder cancer after radical cystectomy

Background and aims To evaluate the prognostic significance of preoperative creatine kinase (CK) levels in bladder cancer (BCa) patients who underwent radical cystectomy (RC). Materials and methods 570 BCa patients with RC were identified between 2010 and 2020. 108.5 U/L of CK levels were defined as the cutoff value. Logistic regression analysis and Cox regression models were performed to evaluate the association between CK levels and oncologic outcomes. Subgroup analyses were performed to address cofounding factors. Results Preoperative low CK levels were associated with worse recurrence-free survival (RFS, log-rank P = 0.001) and overall survival (OS, log-rank P = 0.002). Multivariate analysis revealed that preoperative low CK levels were an independent predictor for worse RFS (hazard ratio [HR]: 1.683; P < 0.001) and OS (HR: 1.567; P = 0.002). Conclusions The preoperative low CK level independently predicts worse survival outcomes in BCa after RC. Incorporating it into prediction models might be valuable to assist risk stratification.