Abstract: PD19-04
Sources of Funding: University of California, Davis Academic Senate

Introduction

The use of intravesical chemotherapy (IC) immediately following transurethral resection of bladder tumor (TURBT) for low grade (LG) non muscle invasive bladder cancer (NMIBC) has been well demonstrated to reduce local recurrence and is supported by current guidelines. We sought to demonstrate patterns of uptake for this practice as well as its impact on outcomes at a population level as an initial step in developing quality improvement initiates in NMIBC.

Methods

Incident cases of LG Ta or T1 NMIBC diagnosed between 2005 and 2012 were identified from the California Cancer Registry and linked to hospital records of the Office of Statewide Health Planning and Development. Tumor, patient, and hospital characteristics were included in the analysis. We determined rates of IC utilization following TURBT in patients with LG Ta or T1 NMIBC. Multivariable logistic regression models were utilized to determine predictors of IC utilization. Cumulative incidence functions and Cox Proportional Hazards (PH) models were used to determine predictors of recurrence-free survival (RFS), bladder cancer-specific survival (CSS), and overall survival (OS) with utilization of IC as the primary effector variable.

Results

The final cohort consisted of 10,031 patients with LG NMIBC diagnosed in California between 2005 and 2012, with initial TURBT ≤ 45 days from diagnosis. The overall rate of IC utilization was 5.1%, but demonstrated an increase from 1.7% (2005-2006) to 9.6% (2011-2012). On multivariable logistic regression analysis, variables associated with increased odds of immediate IC instillation included more recent year of diagnosis (OR 1.74, CI 1.60-1.90 for 2 year increments). Factors associated with lower odds of receiving IC included Hispanic race (OR 0.62, CI 0.43-0.88) and Asian/Pacific Islander race (OR 0.58, CI 0.37-0.91). The cumulative incidence of recurrence at 24 months for patients who received IC was 25.2% compared to 30.2% among those that did not receive IC. On multivariable Cox PH analysis, use of IC was significantly associated with an 18% improvement in RFS (HR 0.82, CI 0.70-0.97).

Conclusions

Utilization of IC for LG NMIBC remains dismally low in routine practice, with less than 10% of patients receiving this standard of care even in more recent years. Poor utilization of this practice is associated with increased rates of recurrence. Strategies utilizing robust implementation of scientific methods should be studied as a means to overcome a major shortcoming in the quality of care provided to patients with LG NMIBC.

Funding

University of California, Davis Academic Senate