Racial/ethnic differences in tumor biology and treatment outcomes in women with ductal carcinoma in situ.

BACKGROUND

Racial differences in invasive breast cancer exist, but less is known about ductal carcinoma in situ. Our aim was to assess racial/ethnic differences in ductal carcinoma in situ tumor biology and treatment.

METHODS

Adults with ductal carcinoma in situ were identified from the National Cancer Database, 2012-2021. Pairwise comparisons were evaluated among racial/ethnic groups with χ or Wilcoxon tests. Multivariable logistic regression models evaluated outcome predictors for treatment and time to treatment.

RESULTS

Non-Hispanic Black patients had larger mean tumor size (2.2 cm, P ≤ .001). Non-Hispanic Black and Hispanic patients more frequently presented with multicentric disease (14.7% and 14.3%, P < .001). Non-Hispanic White patients had more grade III (45.1%, P < .01) and estrogen receptor-negative disease (14.2%, P < .04). On multivariable analysis, non-White race/ethnicity patients were less likely to undergo primary-site surgery (non-Hispanic Black odds ratio, 1.80; Hispanic odds ratio, 1.23; Asian/Pacific Islander odds ratio; 1.45, vs non-Hispanic White each P ≤ .002), as were uninsured and Medicaid-insured (uninsured odds ratio, 2.76; Medicaid odds ratio, 1.39; vs private insurance, both P < .002). Asian patients were more likely to undergo mastectomy (odds ratio, 1.08; 95% confidence interval, 1.02-1.15, P = .007), along with younger age (odds ratio, 0.64, P < .001), and multicentricity (hazard ratio, 2.23, P < .001). For breast conservation, radiation was less frequent among Hispanic patients (68.8%, P < .001). For estrogen receptor-positive ductal carcinoma in situ, non-Hispanic Black patients had the greatest receipt of endocrine therapy (61.9%%, P < .001) and Asian patients the lowest (56.9%, P < .001). On multivariable analysis, non-White race/ethnicity, uninsured, and Medicaid were associated with longer times from diagnosis to first surgery and from definitive surgery to radiation start.

CONCLUSIONS

Racial/ethnic differences exist in ductal carcinoma in situ tumor biology and treatment, both of which may contribute to poorer outcomes in disparate groups.