(BSPOT12) Racial and Ethnic Disparities in Robot-Assisted Radical Prostatectomy: Physician-level Mechanisms

Background: The mechanisms contributing to documented racial and ethnic disparities in robot-assisted radical prostatectomy (RARP) vs. open radical prostatectomy (ORP) are unclear.

Objectives: To test two surgeon-level treatment hypotheses regarding racial and ethnic disparities in RARP use among prostate cancer patients: (1) segregated treatment and (2) differential treatment.

Methods: We conducted an observational cohort study using New York State Cancer Registry linked to discharge records. We identified patients diagnosed with localized prostate cancer and undergoing RARP or ORP between October 2008 and December 2018 in New York State. The exposure variable was patient race and ethnicity: non-Hispanic White (NHW), non-Hispanic Black (NHB), and Hispanic. For hypothesis (1), we assessed the types of treating surgeons based on their RARP use pattern (high-use surgeons, low-use surgeons, and surgeons at non-RARP facilities). We used multinomial logistic regressions to examine the association between race and ethnicity and treating surgeon type. For hypothesis (2), we assessed patients’ receipt of RARP vs. ORP, individually matching NHB and Hispanic patients to NHW patients treated by the same surgeon on age, year of procedure, and Gleason group. We used logistic regression models to determine the association between race and ethnicity and RARP use. We explored the role of insurance in both analyses.

Results: The full cohort included 18,926 patients (75.1% NHW, 16.9% NHB, 8.0% Hispanic). The mean age at the procedure was 60.4±7.1 years. Compared with NHW patients, NHB and Hispanic patients had higher odds of being treated by low-RARP-use surgeons (vs. high-RARP-use surgeons) (OR [95% CI] 1.76[1.06-2.94] and 2.16[1.20-3.88] respectively) and by surgeons at a non-RARP facility (OR [95% CI]: 4.60[2.58-8.23] and 4.19[2.18-8.07], respectively). In the matched cohorts, NHB and Hispanic patients were less likely to receive RARP than NHW patients (OR [95% CI]: 0.78[0.62-0.98] and 0.75[0.57-1.00], respectively). Both pathways were partially mediated by patients’ insurance.

Conclusions: Racial and ethnic disparities in RARP use in prostate cancer treatment may involve surgeon-level mechanisms affecting access to care and the process of care. Identifying and addressing multilevel barriers to equitable surgical treatment is needed for reducing racial and ethnic disparities among prostate cancer patients.