This study investigates associations between hospital and surgeon volume, and racial differences in recurrence after surgery for prostate cancer.
Data from the 1991 to 2002 Surveillance, Epidemiology, and End-Results-Medicare database were examined for 962 black and 7387 white men who received surgery for prostate cancer within 6 months of diagnosis during 1993–1999. Cox regression models were used to estimate the relationships between volume (grouped in tertiles), recurrence or death, and race, controlling for age, Gleason grade, and comorbidity score.
Prostate cancer recurrence-free survival rates improved with hospital and surgical volume. Black men were more likely to experience recurrence than white men [hazard ratio (HR) = 1.34; 95% confidence interval (CI): 1.20–1.50]. Stratification by hospital volume revealed that racial differences persisted for medium and high volume hospitals, even after covariate adjustments (medium HR = 1.30, 95% CI: 1.04–1.61; high HR = 1.36, 95% CI: 1.07–1.73). Racial differences persisted within medium and high levels of surgeon volume as well (medium HR = 1.43, 95% CI: 1.10–1.85; high HR = 1.57, 95% CI: 1.14–2.16).
High hospital and physician volumes were not associated with reduced racial differences in recurrence-free survival after prostate cancer surgery, contrary to expectation. This study suggests that social and behavioral characteristics, and some aspects of access, may play a larger role than organizational or systemic characteristics with regard to recurrence-free survival for this population.