Preoperative abdominal fat distribution and systemic immune inflammation were associated with response to intravesical Bacillus Calmette-Guerin immunotherapy in patients with non-muscle invasive bladder cancer

Abstract

Objective: To investigate the predictors of response to intravesical Bacillus Calmette-Guerin (BCG) immunotherapy for intermediate and high-risk non-muscle invasive bladder cancer (NMIBC) patients.

Materials and methods: We retrospectively analyzed the clinicopathological data of 184 intermediate and high risk NMIBC cases receiving transurethral resection of bladder tumor (TURBT) and intravesical BCG immunotherapy from December 2014 to April 2021 at our center. All patients were divided into BCG responders and non-responders. Multivariate Logistic regression analysis was performed to identify the independent predictors of response to intravesical BCG immunotherapy. Univariate and multivariate Cox regression analyses were applied to explore the independent prognostic factors of recurrence-free survival (RFS). Receiver operating characteristic (ROC) curve and Kaplan-Meier survival analysis were also utilized.

Results: The RFS of BCG responders was significantly increased compared with BCG non-responders. Multivariate Cox regression analysis demonstrated that low grade, pTa stage, non-CIS, lower relative visceral fat area (rVFA) and lower systemic immune inflammation index (SII) were independent prognostic factors of increased RFS after intravesical BCG immunotherapy. Multivariate Logistic regression analysis demonstrated that pTa stage, low grade, non-CIS, low rVFA, and low SII were independent predictors of response to intravesical BCG immunotherapy. Kaplan-Meier survival analysis indicated that the RFS of patients in low rVFA group or low SII group was significantly increased in comparison with those in high rVFA group or high SII group. ROC curve analysis showed that the area under ROC (AUC) of including SII and rVFA was significantly increased, indicating that the inclusion of preoperative SII and rVFA could significantly improve the predictive efficiency.

Conclusions: Low grade, pTa stage, non-CIS, preoperative lower rVFA and lower SII were vital independent predictors of response to intravesical BCG immunotherapy and were associated with preferable prognosis in NMIBC patients. The inclusion of preoperative SII and rVFA could significantly improve the predictive efficiency.

Keywords: Abdominal fat distribution; Bacillus calmette-guerin; Non-muscle invasive bladder cancer; Systemic immune inflammation index; Therapeutic response.