Deconstructing racial disparities in timely treatment of triple-negative breast cancer: A causal mediation analysis.

PURPOSE: Racial disparities in cancer care are often attributed to race rather than the structural factors through which they emerge. This study quantified how socioeconomic and institutional factors mediate treatment delays in triple-negative breast cancer (TNBC).

METHODS

Using the National Cancer Database (2004-2022), we identified patients with stage I-III TNBC who initiated definitive treatment. Race/ethnicity was categorized as non-Hispanic White (NHW), non-Hispanic Black (NHB), Hispanic, or Other. Treatment delay was defined as >30 days from diagnosis to first treatment. Causal mediation analysis estimated the contribution of education, income, comorbidities, insurance status, and facility, stratified by treatment sequence.

RESULTS

Delays were most pronounced among patients receiving chemotherapy first. Mediators explained 40 ​%, 46 ​%, and 23 ​% of the treatment delays among NHB, Hispanic, and Other patients, respectively. Education was the strongest mediator.

CONCLUSIONS

Targeting chemotherapy-first patients, particularly through educational interventions, may be key to reducing disparities in timely treatment for TNBC.