Abstract Background: Guidelines support both breast-conserving surgery (BCS) with radiation and mastectomy for treatment of early breast cancer, but emerging evidence favoring BCS challenges the practice of universally offering both options to patients. There is currently no comparative study assessing health-related quality of life outcomes (HRQoL) across BCS, medically necessary (Mast-MN), and patient preference mastectomy (Mast-PP). This study compared the preoperative and six-month postoperative change in HRQoL in aspects of mental, physical health, and satisfaction between these surgical approaches. Methods: This prospective cohort study enrolled breast cancer surgery patients between 2021 - 2024 at our provincial referral center. Participants completed surveys measuring mental and physical health preoperatively and six-months postoperatively. The BREAST-Q questionnaire was used to assess breast cancer specific outcomes including breast satisfaction, psychosocial, sexual, and chest physical well-being. General patient-reported outcomes were categorized in depression, anxiety, pain, and perceived health. Results: A total of 494 patients meeting inclusion/exclusion criteria completed both pre- and six-month postoperative surveys. Of these, 343 underwent BCS, 104 Mast-MN, and 47 Mast-PP. On average, BCS was associated with a clinically significant increase in breast satisfaction (+4.3) and physical-chest well-being (+7.5). Mast-PP showed a decline in physical-chest well-being (−5.6), while Mast-MN showed reductions in breast satisfaction (−6.2), psychosocial (−5.4), and sexual well-being (−12.2). In multivariable regression, both Mast-PP (β = −7.91, 95% CI: −15.2 to −0.63, p = 0.033) and Mast-MN (β = −12.3, 95% CI: −17.4 to −7.13, p 0.001) were associated with significantly lower postoperative breast satisfaction compared to BCS. There was no significant difference in depression, anxiety, pain, or perceived health scores within and across the surgical modalities. Conclusions: BCS was associated with significantly greater breast satisfaction postoperatively, and trends toward improved chest physical well-being compared to both medically necessary and patient preference mastectomy. When deciding surgical approach, patients should be counseled on these quality-of-life considerations when BCS is feasible. Citation Format: C. Liu, M. Deban, J. Newman-Bremang, R. Warburton, C. Dingee, J. Pao, A. Bazzarelli, J. Sutherland, E. McKevitt. Comparison of health-related quality of life outcomes in breast cancer patients undergoing breast-conserving surgery, medically necessary mastectomy, and patient preference mastectomy: a prospective study abstract. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS1-02-12.
Liu et al. (Tue,) studied this question.