Prediction of response to bacillus Calmette-Guérin treatment in non-muscle invasive bladder cancer patients through interleukin-6 and interleukin-10 ratio

This study aimed to evaluate whether the interleukin-6 (IL-6) and interleukin-10 (IL-10) ratio (IL-6/IL-10) can be used as a prognostic marker of recurrence following bacillus Calmette-Guérin (BCG) therapy in patients with high-risk non-muscle invasive bladder cancer (NMIBC). One hundred and twenty-one consecutive urological patients (72 affected by high-risk NMIBC and 49 controls) were selected for this prospective study. Urine samples for dipstick and interleukin analyses were collected from each subject before surgery. All patients underwent transurethral resection of bladder tumours (TUR-BT), followed by six weekly BCG instillations. IL-6 and IL-10 concentrations in urine were determined by solid phase ELISA Quantikine IL-6 and IL-10 Immunoassay. Patients with NMIBC were stratified in accordance with IL-6/IL-10: group A ≤0.09 and group B >0.10. The main outcome measures were time to first recurrence and recurrence rate following BCG therapy. At enrolment, IL-6/IL-10 was not statistically different between patients and controls (p=0.763, degrees of freedom (df)=1, F-test result (F)=0.092). Of the 72 patients with NMIBC, 38 (52.7%) had an IL-6/IL-10 of ≤0.09 (group A), while 34 (47.3%) had an IL-6/IL-10 of >0.10 (group B). A significant difference between IL-6/IL-10 and status at follow-up was found (p=0.016, df=1, χ(2)=5.800). The Kaplan-Meier curves demonstrated that group B patients had a significantly higher probability of being recurrence-free than group A patients [p=0.003; recurrence rate (RR)=3.1]. At multivariate analysis, IL-6/IL-10 (p<0.003) and the number of lesions (p<0.001) were identified as independent predictors of BCG response probability. In conclusion, this study highlights the feasible role of IL-6/IL-10 in predicting recurrence following BCG therapy in high-risk NMIBC.