Retrospective study of systemic immune-inflammation index in muscle invasive bladder cancer: initial results of single centre.

Purposes: We aimed to evaluate the prognostic value of the preoperative systemic immune-inflammation index (SII) in patients who underwent radical cystectomy due to muscle invasive bladder cancer (MIBC).

Methods: We researched our cystectomy database between April 2006 and December 2018. Demographic data, operation and postoperative data were recorded. There were 191 MIBC patients who underwent radical cystectomy. After detailed analyses, preoperative SII was calculated by the formula as "(neutrophil) × (platelet)/(lymphocyte)". Cancer-specific survival (CSS) and overall survival (OS) were examined. The prognostic value of SII was analysed with univariate and multivariate Cox proportional hazards regression models. Receiver operating characteristic (ROC) was used to determine the optimum SII. Significant P was P < 0.05.

Results: The mean follow-up was 37 ± 6.7 months. The mean age of patients was 62.1 ± 9 years. The optimal cutoff value of SII was determined as 843 in ROC curve (area under the curve: 0.9; P < 0.001). The CSS and OS were significantly poor in patients with higher SII level (respectively; P < 0.001, P = 0.04). Gender, lymph node involvement, pathologic stage, grade and SII were statistically significant in multivariate Cox proportional hazards regression model for CSS.

Conclusions: Preoperative elevated SII could be an independent prognostic factor in MIBC patients who underwent radical cystectomy. If SII > 843, CSS might be poor. Our results should be confirmed with randomised-controlled prospectively designed future studies with large cohorts.