Prognostic Value of Preoperative Albumin-to-Alkaline Phosphatase Ratio in Patients with Muscle-Invasive Bladder Cancer After Radical Cystectomy

Abstract
Objective: This study investigated the prognostic value of the preoperative albumin alkaline phosphatase ratio (AAPR) in patients with muscle-invasive bladder cancer after radical cystectomy. Materials and Methods: We performed a retrospective, single-center cohort study among patients with muscle-invasive bladder cancer who underwent radical cystectomy and urinary diversion at the Department of Urology Surgery of the Affiliated Hospital of Qingdao University from 2007 to 2015. Cox proportional hazards regression was used to evaluate the relationship between preoperative AAPR and outcomes which include OS and CSS and RFS. Survival analysis was conducted using the Kaplan–Meier method and the log rank test. Results: In total, 174 patients were followed up for 1– 125 months, with a median follow-up of 30 months, 93 survived and 81 patients died. The median serum AAPR level in all patients was 0.62 (range: 0.12– 1.67). In multivariate analysis, the preoperative AAPR showed to be associated with overall survival (OS: HR 0.22,95% CI 0.06 to 0.82, P=0.024), cancer-specific survival (CSS: HR 0.12,95% CI 0.02 to 0.63, P=0.013) and recurrence-free survival (RFS: HR 0.15,95% CI 0.03 to 0.82, P=0.029) after adjustment for potential confounders. Kaplan–Meier analysis showed that patients with low AAPR tertiles had shorter OS, CSS and RFS than patients with high AAPR tertiles (OS: P< 0.001, CSS: P< 0.001, RFS: P< 0.001). The relationship between AARP and OS, CSS and RFS was linear. Conclusion: Preoperative AAPR may be a potentially valuable prognostic marker in patients who underwent radical cystectomy for muscle-invasive bladder cancer.