Factors Mediating Racial/Ethnic Disparities in Delayed Treatment of Breast Cancer

BACKGROUND: Despite improvements, disparities in breast cancer care have led to an inequitable distribution of treatment delays and worse outcomes among patients with breast cancer. This study aimed to quantify the contribution of mediators that may explain racial/ethnic disparities in breast cancer treatment delays. PATIENTS AND METHODS: We conducted a retrospective analysis of patients from the National Cancer Database with stage I–III breast cancer who underwent surgical resection. Mediation analyses estimated the extent to which racial/ethnic disparities in the distribution of patient characteristics account for racial/ethnic disparities in delayed treatment. RESULTS: Of the 1,349,715 patients with breast cancer included, 10%, 5%, and 4% were Black, Hispanic, and other non-white race/ethnicity, respectively. Multivariable models showed that patients in these racial/ethnic groups had 73%, 81%, and 24% increased odds of having a treatment delay relative to white patients. Mediation analyses suggested that 15%, 19%, and 15% of the treatment delays among Black, Hispanic, and other non-white race/ethnicity patients, respectively, are explained by disparities in education, comorbidities, insurance, and facility type. Therefore, if these mediators had been distributed equally among all races/ethnicities, a reduction of 15–19% in the delayed treatment disparities experienced by minority patients would have been observed. Academic facility type was the factor that could yield the largest reduction in time to treatment disparities, contributing to 8–13% of racial/ethnic disparities. CONCLUSIONS: Patients with breast cancer who identified as Black, Hispanic, and other non-white races/ethnicities are exposed to longer treatment delays relative to white patients. Efforts to equalize mediators could remove substantial portions of racial/ethnic disparities in delayed treatment.