Older women have unfortunately been underrepresented in breast cancer clinical trials, with the majority of studies being restricted to patients younger than 70 years. Elderly patients are an inhomogeneous group and frequently suffer from comorbidities and/or impaired organ functions. These facts may often lead to death from causes other than cancer, thus nullifying any possible benefit of adjuvant treatment; furthermore, they render extrapolation of standard treatment recommendations to the elderly potentially hazardous, particularly with respect to chemotherapy. Specific clinical trials are therefore needed to investigate adjuvant treatments tailored for the heterogeneous older population.