Impact of chronic kidney disease on oncological outcomes in patients with high-risk non-muscle-invasive bladder cancer who underwent adjuvant bacillus Calmette-Guérin therapy

Abstract

Objectives: To investigate the impact of chronic kidney disease (CKD) on oncological outcomes in patients with high-risk non-muscle invasive bladder cancer (NMIBC) who underwent adjuvant induction bacillus Calmette-Guérin (BCG) therapy after transurethral resection of bladder tumor (TURBT).

Materials and methods: We conducted a multi-institutional retrospective study assessing 209 patients with high-risk NMIBC who underwent TURBT and subsequent adjuvant induction BCG therapy from December 1998 to April 2019. Patients were divided into 2 groups: those with preoperative estimated glomerular filtration rate (eGFR) ≥ 60 ml/min/1.73 m² (non-CKD group), and those with eGFR < 60 ml/min/1.73 m² (CKD group). Primary endpoints were intravesical recurrence-free survival (RFS) and muscle-invasive bladder cancer (MIBC)-free survival. Background-adjusted multivariate analyses with the inverse probability of treatment weighting (IPTW) method using the propensity score were performed to evaluate the impact of CKD on intravesical RFS, MIBC-free survival, metastasis-free survival, cancer-specific survival, and overall survival. Moreover, multivariable analyses were performed to assess the impact of CKD on intravesical recurrence and MIBC progression, adjusting for the competing risk of death using the Fine-Gray competing risk regression model.

Results: Median age and follow-up period after TURBT were 72 years and 45 months, respectively. Of 209 patients, 71 (34%) were diagnosed with CKD before TURBT. Background-adjusted multivariate analyses with the IPTW method indicated that CKD was significantly associated with shorter intravesical RFS, MIBC-free survival, metastasis-free survival, cancer-specific survival, and overall survival. In the Fine-Gray competing risk regression model, CKD showed significantly higher probabilities of intravesical recurrence and MIBC progression, with an adjusted subdistribution hazard ratio of 1.886 (95% confidence interval 1.069-3.330, P = 0.028) and 3.740 (95% confidence interval 1.060-13.20, P = 0.040), respectively.

Conclusions: CKD presents a risk factor of poor oncological outcomes in patients with high-risk NMIBC who underwent adjuvant induction BCG therapy after TURBT.

Keywords: Chronic kidney disease; High-risk; Immune dysfunction; Non-muscle-invasive bladder cancer; Oncological outcomes; bacillus Calmette-Guérin.