Impact of carcinoma in situ of bladder at transurethral resection and radical cystectomy on survival: Retrospective multicenter study

Abstract

Purpose: Carcinoma in situ (CIS) of the bladder is a high-grade, non-invasive lesion known to increase the risk of recurrence and progression. However, the prognostic significance of CIS identified at transurethral resection of bladder tumor (TURB) versus radical cystectomy (RC) remains controversial. This study aimed to evaluate the impact of CIS at different treatment stages on recurrence-free survival (RFS) and cancer-specific survival (CSS). Materials and Methods: A retrospective multicenter study was conducted using data from 2,553 patients who underwent TURB followed by RC between 2010 and 2019 across eleven Korean institutions. Kaplan-Meier survival curves and Cox proportional hazards models were used to assess the association of CIS at TURB and RC with RFS and CSS, adjusting for clinicopathological variables. Results: CIS was identified in 731 TURB specimens (28.6%) and 821 RC specimens (32.2%). Patients with CIS at TURB had significantly higher RFS (p<0.001) and CSS (p=0.002) compared to those without. In multivariate analysis, CIS at TURB was independently associated with better RFS (hazard ratio [HR] 0.787, p=0.001) but not CSS (HR 0.989, p=0.905). CIS at RC showed no significant association with either RFS or CSS. Independent predictors of poor survival included advanced stage, lymph node involvement, lymphovascular invasion, and positive surgical margins. Adjuvant therapy was associated with improved CSS. Conclusions: CIS at TURB is associated with a lower recurrence risk following RC, whereas CIS in RC specimens has limited prognostic impact. These findings suggest CIS at TURB may carry different prognostic implications than traditionally assumed, warranting careful clinical interpretation.