Differences in breast cancer stage and survival by race and ethnicity have previously been identified, though few studies evaluating women in different racial and ethnic subgroups have been reported. In this retrospective population-based cohort study, Li et al evaluated the relationships between 17 different races and ethnicities and breast cancer stage, treatment, and mortality. Blacks, American Indians, Hawaiians, Indians and Pakistanis, Mexicans, South and Central Americans, and Puerto Ricans had a 1.4- to 3.6-fold greater risk of stage IV breast cancer compared with non-Hispanic whites. Blacks, American Indians, Hawaiians, Vietnamese, Mexicans, South and Central Americans, and Puerto Ricans had a 20% to 200% greater risk of mortality following a breast cancer diagnosis. Li et al identified important differences in breast cancer stage, treatments, and mortality by race and ethnicity. Breast cancer survival may be improved by targeting socioeconomic factors that likely underlie these differences.