Correlation of Insurance, Race, and Ethnicity with Pathologic Risk in a Controlled Retinoblastoma Cohort: A Children's Oncology Group Study

Purpose To determine whether insurance status, race, and ethnicity correlate with increased retinoblastoma invasiveness as a marker of both risk and time to diagnosis. Design Retrospective case-control study. Participants All 203 patients from the United States enrolled in the Children's Oncology Group (COG) trial ARET0332, a study of patients with unilateral retinoblastoma requiring enucleation. Main Outcome Measures All surgical specimens underwent pathologic review to determine the presence of well-defined histopathologic features correlating with a higher risk of disease progression. Insurance status, race, and ethnicity were compiled from the study record for each patient. Results On institutional pathologic review, nonprivate insurance, nonwhite race, and Hispanic ethnicity all correlated significantly with a greater rate of high-risk pathologic findings. Hispanic ethnicity remained a significant predictor on multivariate analysis. On central pathologic review, these correlations remained but did not reach statistical significance. The differences in results from institutional versus central pathologic reviews appeared to be due to a higher likelihood of patients in minority groups of being misclassified as high risk by institutional pathologists. Conclusions In this controlled study population of patients with retinoblastoma who had central pathologic review, our findings suggest a higher rate of more advanced disease associated with nonprivate insurance, nonwhite race, and Hispanic ethnicity; these findings may be due to delays in diagnosis for these groups. Future work should use direct methods to study the impact of other variables, including English-language proficiency and socioeconomic status. Further effort also should focus on where in the diagnostic process potential delays exist, so that interventions can be designed to overcome barriers to care for these groups. In addition, potential systematic differences in pathologic reads based on demographic variables deserve further study.