Racial disparities in breast cancer mortality--letter.

I read with great interest your article on racial disparities in breast cancer detection, treatment, and outcomes (1). My comments below are aimed at specifically addressing the disparities in the utilization of adjuvant treatment. The simulation model applied in this study claims to predict the differential impact of adjuvant treatment on breast cancer mortality. But the increase in mortality attributed to the underutilization of adjuvant treatment is based solely on systemic treatment. To my knowledge, the models discussed in this article do not employ basecase radiotherapy use. It has been well established by multiple randomized studies that adjuvant radiation therapy not only significantly decreases the risk of locoregional recurrence but also, most importantly, confers a survival benefit (2). Similar to the tale of use of systemic treatment, black women are also significantly likely to underutilize, more likely to delay, andmore likely to prematurely discontinue adjuvant radiation therapy than do white women (3–6). Because black women present with more advanced disease and poor prognosticators than white women (7), they stand to glean a significant benefit from adjuvant radiation therapy and significant detriment from the underuse thereof (8). If the use of radiation therapy was considered in the algorithm, the predicted impact of adjuvant therapy on mortality would be substantially higher, particularly in black women. There is some credence to the dogma that there are yet unknown factors that contribute to higher breast cancer mortality rates in black women. However, without consideration of all measurable factors including the use of adjuvant radiation therapy, inferring that a substantial part of the mortality disparity is due to unexplained factors may be presumptuous. The results of this studywill undoubtedly contribute to the body of literature on racial disparities in cancer treatment. However, we cannot ignore the deleterious impact on locoregional control with the underuse of adjuvant radiation, or the significant survival benefit derived from the use thereof. We must diligently and collaboratively endeavor to identify all factors that significantly impact racial differences in treatment and outcomes to inform our practice and educate our patients accordingly. Then and only then will we tangibly close the gap in cancer disparities.