Oncologic Outcome of Endoscopic Assisted Breast Surgery Compared with Conventional Approach in Breast Cancer: An Analysis of 3426 Primary Operable Breast Cancer Patients from Single Institute with and Without Propensity Score Matching.

Background: Endoscopy-assisted breast surgery (EABS) performed through minimal axillary and/or peri-areolar incisions is a possible alternative to conventional breast surgery (CBS) for certain patients with breast cancer. In this study, we report the oncologic safety results of EABS compared with CBS.

Methods: Patients underwent EABS for breast cancer during the period June 2010 to March 2020 were collected from the EABS database from single institute, and another cohort of patients, who received CBS, were identified to determine the effectiveness and oncologic safety of EABS. A case-control study was conducted using propensity score matching (PSM) to prevent bias from cases selection.

Results: A total of 3426 patients were enrolled in the current study, including 405 patients receiving EABS and 3021 underwent CBS. Before PSM, patients selected for EABS tend to be smaller in tumor size, node negative, early stage, low histologic grade, and HER-2 negative. After PSM, 343 patients underwent EABS were compared with another 343 patients received CBS. The margin involved rate in EABS group is 2.6%, and 5.6% in CBS group (p = 0.054) after PSM. In breast conserving cases, the margin involved rates were 2% in EABS group, and 7.2% in CBS group (p = 0.04). In Kaplan-Meier survival curves analysis, there was no difference in local regional recurrence (p = 0.89), distant metastasis (p = 0.08), and overall survival (p = 0.14).

Conclusion: The preliminary oncologic safety analysis from current study showed EABS is a safe procedure and results in low margin involved rate, and no increase of locoregional recurrence, distant metastasis or mortality compared with CBS.