BackgroundFor the estimated 10 million women in the United States who meet the high-risk criteria for breast cancer, evidence-based interventions may reduce the risk of breast cancer by 50-65%. Even with substantial evidence supporting preventive medication for risk reduction, there is significant lack of uptake and adherence. The purpose of this study was to characterize the experience of women at high risk for breast cancer and define the content domain for a patient-reported outcomes (PRO) measure of symptom burden from breast cancer risk and risk reducing medication. MethodsThirty women at high risk for breast cancer and receiving risk reducing medication participated in single qualitative interviews. Content analysis was used to identify the symptom burden. An expert panel review rated the relevance of symptoms identified in the qualitative interviews to establish the items for inclusion in a PRO symptom burden measure. ResultsParticipants had a mean age of 54.6 years; 43.3% self-identified as Hispanic and 20.0% self-identified as Black. Content analysis found 20 symptoms related to both risk and preventive treatment, with 8 symptoms reported by ≥ 20% of women. All women described distress related to their risk and preventive care. Treatment-related symptoms varied based on history of risk-reducing surgery and type of endocrine therapy. Women described symptom-related interference with relationships, work, enjoyment of life, and adherence to risk reducing medication. ConclusionsWomen with a known high risk of breast cancer and receiving preventive care experience a unique symptom burden including multiple symptoms and functional impact related to symptoms.