Medicaid expansion, chemotherapy delays, and racial disparities among women with early-stage breast cancer

Background: Medicaid expansion under the Affordable Care Act extends eligibility for participating states and has been associated with improved outcomes by facilitating access to care. Delayed initiation of adjuvant chemotherapy is associated with worse outcomes among patients with early-stage breast cancer (BC). The impact of Medicaid expansion in narrowing delays by race and ethnicity has not been studied, to our knowledge. Methods: This was a population-based study using the National Cancer Database. Patients diagnosed with primary early-stage BC between 2007 and 2017 residing in states that underwent Medicaid expansion in January 2014 were included. Time to chemotherapy initiation and proportion of patients experiencing chemotherapy delays (>60 days) were evaluated using difference-in-difference and Cox proportional hazards models in preexpansion and postexpansion periods according to race and ethnicity. Results: A total 100 643 patients were included (63 313 preexpansion and 37 330 postexpansion). After Medicaid expansion, the proportion of patients experiencing chemotherapy initiation delay decreased from 23.4% to 19.4%. The absolute decrease was 3.2, 5.3, 6.4, and 4.8 percentage points (ppt) for Black, Hispanic, White, and Other patients. Compared with White patients, statistically significant adjusted difference-in-differences were observed for Black (_2.1 ppt, 95% confidence interval [CI] = _3.7% to _0.5%) and Hispanic patients (_3.2 ppt, 95% CI = _5.6% to _0.9%). Statistically significant reductions in time to chemotherapy between expansion periods were observed among White patients (adjusted hazard ratio = .11, 95% CI = 1.09 to 1.12) and those belonging to racialized groups (adjusted hazard ratio =1.14, 95% CI = 1.11 to 1.17). Conclusions: Among patients with early-stage BC, Medicaid expansion was associated with a reduction in racial disparities by decreasing the gap in the proportion of Black and Hispanic patients experiencing delays in adjuvant chemotherapy initiation.