Abstract PS2-01-28: Factors influencing surgical decision-making in breast cancer using patient-reported outcomes- A multicenter collaborative study-

Abstract Background: Surgical decision-making in breast cancer involves not only clinical and oncological considerations but also psychosocial factors such as personal values, social support, and anticipated quality of life. Although shared decision-making (SDM) is increasingly emphasized, factors influencing patients’ surgical choices remain unclear. This study aimed to identify determinants associated with the selection of total mastectomy (MT), breast-conserving surgery (BCS), or immediate breast reconstruction (IBR) using patient-reported outcomes. Patients and Methods: A multicenter study was conducted across six institutions in Japan. We included 577 female patients who underwent breast cancer surgery between 2008 and 2018. Using patient-reported outcomes, we collected data on sociodemographic background and 15 decision-influencing factors, including opinions of healthcare providers, family, and peers; radiation therapy; fear of recurrence; hospitalization; and perceived impacts on childcare, work, and hobbies. Patients were categorized into MT, BCS, or IBR groups. Chi-square tests were used for group comparisons, and multinomial logistic regression was performed using the IBR group as the reference. Results: Among 577 patients, 194 underwent MT, 185 BCS, and 198 IBR. The mean age was 53.6 years (±11.5), with the IBR group significantly younger (48.2) than MT (58.1) and BCS (54.8) (p