Systemic immune-inflammation index predicts prognosis of bladder cancer patients after radical cystectomy

Abstract

BACKGROUND: The systemic immune-inflammation index (SII) has been used as a prognostic marker for several cancer types, but there is no in-depth study in bladder cancer. This study evaluated the potential utility of the SII as a prognostic factor in patients with bladder cancer after radical cystectomy. METHODS: A retrospective analysis of 209 patients with bladder cancer who had undergone radical cystectomy and were randomized into primary (N=139) and validation (N=70) cohorts was conducted. The overall survival (OS) was calculated using the Kaplan-Meier survival curves. The prognostic value of the SII in primary and validation cohorts were analyzed by using the Cox regression model. A SII-based nomogram for bladder cancer was produced in R software. RESULTS: A high SII (>507) was associated with poor prognosis in bladder cancer patients. Univariate and multivariate analyses revealed that the SII was an independent predictor for OS. The SII emerged as an independent prognostic factor that provided more accurate prognostic prediction than neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and C-reactive protein/albumin ratio (CAR), in the primary and validation cohorts. The nomogram had better accuracy and discrimination than tumor, lymph node, metastasis (TNM) classification. The concordance index values of nomogram were 0.82 for the primary cohort and 0.784 for the validation cohort. CONCLUSIONS: The SII can serve as an independent predictor of OS in patients who have undergone radical cystectomy for bladder cancer, and was found to be a better predictor of prognosis than NLR, PLR, and CAR. The nomogram is a reliable model for predicting postoperative OS of patients after radical cystectomy.