Abstract P5-22-20: Oncologic safety of endoscopic assisted breast surgery compared with conventional breast surgery: An analysis of 1295 primary operable breast cancer patients from single institute
Authors: Lai H-W , Chen S-T , Chen D-R , Kuo S-J 
Published: February 2018

Abstract
Background:Endoscopy-assisted breast surgery (EABS) performed through minimal axillary and/or periareolar incisions is a possible alternative to open surgery for certain patients with breast cancer. In this study, we report the oncologic safety results of EABS compared with conventional breast surgery (CBS).
Methods: The medical records of patients who underwent EABS for breast cancer during the period June 2010 to April 2017 were collected from the EABS database at Changhua Christian Hospital, a tertiary medical center in central Taiwan. Data on clinicopathologic characteristics, type of surgery, method of breast reconstruction, margin involvement, locoregional recurrence, distant metastasis and overall survival were collected and compared to another cohort of patients, who received CBS at the same hospital, to determine the effectiveness and oncologic safety of EABS.
Results: A total of 1295 patients were enrolled in current study, including 214 patients receiving EABS and 1081 patients underwent CBS. The mean age of them were 50.4 ± 9.4 years-old in EABS group, and 52.5 ± 11.3 in CBS group (P=0.01). Patients who received EABS were associated with more early stage breast cancer than patients with CBS group (P&lt;0.01). The margin involved rate was 3.3% in EABS group, and 6.1% in CBS group (P=0.11). During a median follow-up of 57.7 ± 24.7 months, the locoregional recurrence was 3.7% in EABS group, and 7.3% in CBS group (P=0.06). The distant metastasis rate was 2.8% in EABS group and 10.3% in CBS group (P=0.001). The overall survival rate was 99.5% in EABS group, and 93.8% in CBS group.
Comparison of endoscopic assisted breast surgery (EABS) and conventaional breast surgery (CBS) EABSCBSP value N=214 (%)N=1081 (%) Pathology tumor size (cm)2.2 ± 1.62.3 ± 1.70.414Operation method Mastectomy141 (65.9)530 (49.0)&lt;0.001Breast conserving surgery73 (34.1)551 (51.0) Lymph node surgery SLNB only149 (69.6)534 (49.4)&lt;0.001SLNB then ALND40 (18.7)244 (22.6) ALND7 (3.3)259 (24.0) Not done18 (8.4)44 (4.1) Breast reconstruction Yes108 (50.5)930 (86.0)&lt;0.001No106 (49.5)151 (14.0) Lymph node metastasis Yes49 (24.7)375 (35.0).0.005No149 (75.3)797 (65.0) Stage 055 (25.7)160 (14.8)&lt;0.001I67 (31.3)340 (31.5) II84(39.2)439(40.7) III8(3.8)136(12.6) Grade I35 (17.6)178 (17.2)0.365II118 (59.3)566 (54.8) III46 (23.1)288 (27.9) Margin status Involved7 (3.3)66 (6.1)0.110Not-involved207 (96.7)1015 (93.9) Locoregional recurrence Yes8 (3.7)79 (7.3)0.057No206 (96.3)1002 (92.7) Distance metastasis Yes6 (2.8)111 (10.3)0.001No208 (97.2)970 (89.7) Survival Yes213 (99.5)1014 (93.8)0.001No1 (0.5)67 (6.2) SLNB: sentinel lymph node biopsy, ALND: axillary lymph node dissection.
Conclusion: The preliminary oncologic safety analysis from our institution showed that EABS is a safe procedure and results in low margin involved rate, and no increase of locoregional recurrence, distant metastasis or mortality compared with conventional breast surgery. However, this study might be biased due to its retrospective nature and possible selection bias.Ongoing case controlled comparison study will be performed to further consolidate the oncologic safety of endoscopic assisted breast surgery.
Citation Format: Lai H-W, Chen S-T, Chen D-R, Kuo S-J. Oncologic safety of endoscopic assisted breast surgery compared with conventional breast surgery: An analysis of 1295 primary operable breast cancer patients from single institute [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-22-20.