Abstract PO5-03-01: Clinical outcomes of breast-conserving surgery under local anesthesia versus general anesthesia for breast malignancies
Authors: Lee Hawjeong , Jo Hyunjong , Kang Eunhye , Jung Ji-Jung , Shin Ik Beom , Byeon Jin Young , Lim Changjin , Kim Hong-Kyu , Moon Hyeong-Gon , Han Wonshik , Lee Han-Byoel 
Published: May 2024

Abstract
Clinical outcomes of breast-conserving surgery under local anesthesia versus general anesthesia for breast malignancies Hwajeong Lee, Hyunjong Jo, Eunhye Kang, Ji-Jung Jung, Ik Beom Shin, Jin Young Byeon, Changjin Lim, Hong-Kyu Kim, Hyeong-Gon Moon, Wonshik Han, Han-Byoel Lee Purpose With the increase in the incidence and proportion of stage I and in situ breast cancer, there is a growing trend for de-escalation of surgery. Several ongoing trials are evaluating the omission of sentinel lymph node biopsy (SLNB), including the SOUND trial, which showed no difference in disease-free survival. Breast-conserving surgery (BCS) under local anesthesia (LA) could be performed when no axillary surgery is necessary and could potentially reduce the physical and psychological burden on patients caused by surgery compared to BCS under general anesthesia (GA). We aim to compare the clinical outcomes between BCS under LA versus GA in patients who did not require SLNB. Methods We retrospectively collected and analyzed data from 116 patients who received BCS under LA from January 2021 to June 2023 and 260 patients who received BCS under GA in 2022. Clinical tumor size, pathologic tumor size (both including in situ carcinoma), surgical specimen volume, resection margin (RM) positivity, re-excision rate, operation time, and length of hospital stay were compared. Result There was no difference between LA and GA in terms of age, BMI, and proportion of in situ cancer. The LA group had a higher proportion of tumors with clinical tumor size ≤ 2cm. The LA group had a higher RM positive rate (11.2 vs. 5.4%, p=0.043) and re-excision rate (12.9 vs 3.5%, p &lt; 0.001). According to tumor size, the higher RM positivity was only observed in clinical tumor size &gt;1cm & ≤ 2cm group (p=0.039). In patients whose clinical tumor size ≤ 2cm was upgraded to pathologic tumor size &gt; 2cm, there was no difference in RM positivity between the two groups (5/18 [27.8%] vs. 4/34 [11.8%], p=0.247). A smaller surgical specimen volume was excised under LA (22.01 ± 14.11 vs 65.67 ± 48.43 cm3, p &lt; 0.001). The overall operation time (64±16 vs 73±22 min, p &lt; 0.001) and hospital stay (1 ± 0 vs 4 ± 1 days, p &lt; 0.001) was shorter in the LA group Conclusion Breast-conserving surgery under LA showed a higher RM positive rate, of which most were in patients with discordance in clinical and pathologic tumor size. Although this resulted in a higher re-excision rate, the smaller surgical specimen volume, shorter operation time, and hospital stay for BCS under LA could positively impact patient recovery and quality of life. The benefits of LA should be considered when evaluating the de-escalation of surgery for breast malignancies.
Citation Format: Hawjeong Lee, Hyunjong Jo, Eunhye Kang, Ji-Jung Jung, Ik Beom Shin, Jin Young Byeon, Changjin Lim, Hong-Kyu Kim, Hyeong-Gon Moon, Wonshik Han, Han-Byoel Lee. Clinical outcomes of breast-conserving surgery under local anesthesia versus general anesthesia for breast malignancies [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-03-01.