INTRODUCTION: For women ≥70 y old with early-stage hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer, the national guidelines recommend the omission of sentinel lymph node biopsy (SLNB) and post-lumpectomy radiotherapy. However, national-level data suggest these treatments remain common. We utilized a survey-based approach to explore patient-level factors driving overutilization. METHODS: We recruited women ≥70 y old with early-stage hormone receptor-positive/human epidermal growth factor receptor 2-negative breast cancer within 6 mo of surgery. An exploratory cross-sectional survey captured information on offered and pursued treatments, the importance of patient-centered outcomes, and the influence of each outcome on treatment decision-making. Descriptive statistics were used for analysis. RESULTS: 31/51 patients completed the survey with a response rate of 61%. Most patients (86%) received a lumpectomy. Twenty-eight percent of patients received SLNB, and 56% of lumpectomy patients underwent adjuvant radiotherapy. When considering treatment options, the patient-centered outcomes, most important for decision-making, were overall survival, breast-specific survival, and preventing local recurrence, while breast appearance, financial costs, and avoiding the need for pills (endocrine therapy) were the least important. CONCLUSIONS: Patients' treatment decisions align with their values. The correlation between patient-stated values and treatment decisions suggests a perceived mortality benefit of low-value SLNB and radiotherapy. These findings can inform targeted efforts to deimplement low-value care in breast cancer through patient-focused tools and education.