Value of Immunological Biomarkers in Early Prediction of Bacillus Calmette-Guerin Failure in High-Risk Non-muscle-invasive Bladder Cancer

Objectives To investigate the predictive value of different immunological markers on treatment outcomes after bacillus Calmette-Guerin (BCG) induction in high-risk non-muscle-invasive bladder cancer (NMIBC). Patients and Methods Patients who underwent transurethral resection of bladder tumors for NMIBC were assessed for study eligibility. Urine and blood samples were taken from patients at baseline (immediately before the first dose of induction). Urine samples were evaluated for interleukin (IL)-6, IL-8, IL-10, IL-11, and interferon- γ by solid-phase enzyme-linked immunosorbent assay (ELISA). Blood samples were evaluated for epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor-2 (HER2) using quantitative reverse transcriptase-polymerase chain reaction analysis. Each marker was assessed in relation to tumor recurrence. Results Between June 2016 and December 2019, 160 patients were included. Tumor recurrence occurred in 47 (29.38%) patients over a median (IQR) follow-up of 24 (12: 49) months. Using univariate analysis, the following urinary cytokines were associated with higher recurrence: urinary IL-6, 8, 10, 11, and interferon-γ. Also, serum EGFR and HER2 were associated with higher recurrence. On multivariate Cox regression analysis, significant variables include HER2 [HR (95%CI): 2.675 (1.367-5.233), p= 0.004], and IL-11 [HR (95%CI): 0.889 (0.825-0.957), p= 0.002]. Conclusions Serum HER2 and urinary IL-11 could be applied in clinical practice to predict BCG failure in patients with high-risk NMIBC, so those patients could be offered other modalities (radical cystectomy) early with better survival. Further studies are recommended to establish their exact role.