In Reply We thank Long et al and Obeng-Gyasi and Carlos for their thoughtful comments on our investigation using data from the Surveillance, Epidemiology, and End Results (SEER) Oncotype database to compare rates of a high-risk Oncotype DX Breast Recurrence Score (RS) and breast cancer–specific survival between Black and White patients with axillary node–negative, estrogen receptor–positive breast tumors.1 Long et al question whether SEER data are representative of the US population and suggest that we adjust observed estimates using standardized high-risk RS rates. This would indeed produce relative rates that reflect the true population-level difference. Although the cancer registries from which women were sampled are population based, and past investigations have demonstrated that SEER cancer-specific mortality rates for White and Black women with breast cancer were similar to national rates,2 it is possible that our estimates differ from the underlying populations of interest.3 We agree that a population-standardized estimate, if available, would be ideal. However, to the extent that we demonstrated an independent association with high RS by race, we believe that our findings provide valid evidence that Black women disproportionately develop biologically aggressive, estrogen receptor–positive tumors.