In contrast to western high-income nations, the incidence and mortality from breast cancer are increasing in most low and middle-income countries worldwide. Current approaches to breast cancer control developed for populations of high-income societies should not be directly transferred without evaluation. A relevant research agenda includes population differences in tumor biology and metabolization of systemic therapies, cultural and psychosocial issues, and operations in healthcare systems. Highest priority should be given to assessments of clinical downstaging and basic systemic treatment effectiveness in low and middle-income populations. Partnerships of existing organizations in high-income nations with those in low and middle-income countries are currently the most feasible sources of research support. (c) 2008 American Cancer Society.