Racial/ethnic differences in supplemental imaging for breast cancer screening in women with dense breasts.

Background: Mammography is limited when analyzing dense breasts for 2 reasons: (1) breast density masks underlying cancers and (2) breast density is an independent risk factor for cancer. We undertook this study to assess whether there is a racial/ethnic difference in supplemental image ordering for women with dense breasts.

Methods: We conducted a retrospective, observational cohort study of women aged 50-75 from an academic medical center who had completed a screening mammogram between 2014 and 2016 that was read as BI-RADS 1 with heterogeneously or extremely dense breasts or BI-RADS 2 with extremely dense breasts. Data were abstracted on type, timing and frequency of supplemental imaging tests ordered within two years of an initial screening mammogram. Patient characteristics (age, race/ethnicity, insurance, and comorbidities) were also abstracted. We used bivariate and multivariate logistic regression to assess for differences in supplemental imaging ordered by race/ethnicity.

Results: Three hundred twenty-six women met inclusion criteria. Mean age was 58 years: 25% were non-Hispanic white, 30% were non-Hispanic black, 27% were Hispanic, 6% were Asian and 14% unknown. Seventy-nine (24%) women were ordered a supplemental breast ultrasound after the initial screening mammogram. Non-Hispanic black and Hispanic women were less likely to have supplemental imaging ordered compared to non-Hispanic white women (15% and 10%, respectively, vs. 45%, p < 0.0001). After controlling for patient age, ordering physician specialty, insurance, BI-RADS score, breast density, and family history of breast cancer, non-Hispanic black and Hispanic women remained less likely to be ordered supplemental imaging (OR 0.38 [95% CI 0.17-0.85] and OR 0.24 [95% CI 0.10-0.61], respectively, p < 0.0001).

Conclusion: Minority women with dense breasts are less likely to be ordered supplemental breast imaging. Further research should investigate physician and patient behaviors to determine barriers in supplemental imaging. Understanding these differences may help reduce disparities in breast cancer care and mortality.