Abstract PS2-01-16: Feasibility of Systematic Breast-Conserving Surgery Under Local Anesthesia and Sedation: A Large Single-Center Study

Abstract Background: Local anesthesia with sedation (LAS) is widely used in other surgical disciplines but remains underutilized in breast-conserving surgery (BCS), where general anesthesia (GA) is still the standard [1, 2]. Recent reports have demonstrated the potential of LAS in selected breast surgery cases [3-5]. We aimed to evaluate the feasibility of systematically performing BCS under LAS in a high-volume breast cancer center. Methods: We conducted a retrospective study including all patients who underwent BCS ± axillary surgery from September 2021 to December 2023 in our institution. Patients operated under GA during the initial period (Sept 2021-March 2022) were compared to those under LAS (June 2022-Dec 2023), excluding the transition phase. LAS combined intravenous sedation (midazolam, dexmedetomidine, ketamine, remifentanil) with local infiltration (naropeine, lidocaine with epinephrine, saline). Feasibility endpoints included conversion to GA, intraoperative tolerance, and early surgical complications. Results: Of the 948 BCS procedures performed during the study period, 708 (75%) were carried out under LAS. Among the eligible patients during the LAS period, 12 refused local anesthesia and were operated under GA. Only 2 conversions to GA occurred during LAS procedures (0.3%), confirming excellent feasibility. We planned more preoperative wire in the LAS group (80% vs. 59%) because of the aqueous environment making small lesions more difficult to feel. Re-operation rates (for positive margins, hematoma, or infection) did not differ between LAS and GA groups (11% in LAS group vs. 13% in GA group, p=0.34). Axillary procedures were performed in both groups (52% in LAS group and 58% in GA group, n=0.06). Oncoplastic techniques were successfully performed under LAS without compromising safety or outcomes. Conclusions: Our results confirm that systematic BCS under LAS is feasible, safe, and applicable to a wide range of breast surgical procedures, including oncoplastic and axillary surgeries. To our knowledge, this represents the largest reported single-center series of breast-conserving surgery performed under LAS, supporting its broader implementation in routine clinical practice and perioperative optimization strategies. References: 1. D'Alonzo M, Martincich L, Biglia N, et al. Feasibility of breast surgery under local anesthesia in elderly patients. J Surg Oncol. 2020;121(3):446-453. 2. Fischer JP, Nelson JA, Sieber B, et al. Propensity-matched analysis of local versus general anesthesia for outpatient breast surgery. Ann Surg Oncol. 2014;21(10):3274-3280. 3. Boughey JC, Goravanchi F, Pockaj BA, et al. Anesthesia considerations in breast surgery. Breast J. 2020;26(4):727-732. 4. Peled AW, Foster RD, Esserman LJ. Increasing role of local anesthesia with sedation in breast surgery. Ann Surg Oncol. 2015;22(10):3336-3342. 5. Fernandez-Rodriguez M, Castano-Oreja MT, et al. Local anesthesia and sedation in breast-conserving surgery: A valid alternative to general anesthesia. Clin Transl Oncol. 2022;24(3):473-480. Citation Format: D. Hequet, M. Cittanova, R. Salmon, M. Wilhelm, G. Aubry, C. Gout Duracher, J. Seror. Feasibility of Systematic Breast-Conserving Surgery Under Local Anesthesia and Sedation: A Large Single-Center 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 PS2-01-16.