Underutilization of intravesical chemotherapy and immunotherapy for high grade non-muscle invasive bladder cancer in California between 2006-2018: Effect of race, age and socioeconomic status on treatment disparities.

OBJECTIVE:Among patients diagnosed with non-muscle invasive bladder cancer (NMIBC), those with high risk disease have the greatest risk of recurrence and disease progression. The underutilization of intravesical immunotherapy with Bacillus Calmette-Guérin (BCG) has been a longstanding concern in clinical practice. This study aimed to determine the disparities present in receipt of adjuvant intravesical chemotherapy and immunotherapy in treatment of patients with high grade NMIBC following initial transurethral resection of a bladder tumor (TURBT). METHODS:The California Cancer Registry data was used to identify 19,237 patients diagnosed with high grade NMIBC who underwent TURBT. Treatment variables include re-TURBT, re-TURBT and intravesical chemotherapy (IVC) and/or BCG. Independent variables include age, sex, race/ethnicity, neighborhood socioeconomic status (nSES), primary insurance payer and marital status at diagnosis. Multiple logistic regression and multinomial regression models were used to examine variation in the treatments received following TURBT. RESULTS:The proportion of patients receiving TURBT followed by BCG was similar across all racial and ethnic groups (28%-32%). BCG therapy was higher in patients belonging to the highest nSES quintile (37% for highest vs. 23%-26% for the 2 lowest quintiles). In multiple variable analyses, receipt of any intravesical therapy (IVT) was influenced by nSES, age, marital status, race/ethnicity, and insurance type. Patients in the lowest nSES quintile had a 45% less likelihood of receiving IVT compared to the highest nSES group (OR [95%CI]: 0.55[0.49, 0.61]). Race/ethnicity differences in receipt of any adjuvant therapy were noted in the middle to lowest nSES quintile for Hispanic and Asian/Pacific Islander patients when compared to non-Hispanic White patients. When comparing variation in treatment by insurance type at diagnosis, those with Medicare or other insurance were 24% and 30% less likely to receive BCG after TURBT compared to those with private insurance, (OR [95%CI]: 0.76 [0.70, 0.82] and 0.70[0.62, 0.79]) respectively. CONCLUSION:In patients with a diagnosis of high risk NMIBC, disparities in utilization of BCG are seen based on SES, age, and insurance type.