With the ongoing ageing of western societies, the proportion of older breast cancer patients will increase. For several years, clinicians and researchers in geriatric oncology have urged for new clinical trials that address patient-related endpoints such as functional decline after treatment of older patients. The aim of this study was to present an overview of trial characteristics and endpoints of all currently running clinical trials in breast cancer, particularly in older patients. The clinical trial register of the United States National Institutes of Health Differences was searched for all current clinical trials on breast cancer treatment. Trial characteristics and endpoints were retrieved from the register and differences in characteristics between studies in older patients specifically (defined as a lower age-limit of 60 years or older) and trials in all patients were assessed using χ(2) tests. We included 463 clinical trials. Nine trials (2 %) specifically investigated breast cancer treatment in older patients. Ninety-one breast cancer trials included any patient-related endpoint (20 %), while five trials specifically addressing older patients included any patient-related endpoint (56 %, P = 0.02). Five of the trials in older patients incorporated a geriatric assessment (56 %). Clinical trials still rarely incorporate patient-related endpoints, even in trials that specifically address older patients. Trials that are specifically designed for older patients do not often incorporate a geriatric assessment in their design. This implicates that current clinical studies are not expected to fill the gap in knowledge concerning treatment of older breast cancer patients in the next decade.