Abstract P2-14-15: Comparison of recurrence-free survival according to axillary surgery extent for clinical N0, sentinel node(s) positive, primary breast cancer patients who underwent total mastectomy
Authors: Chun Jung Whan , Kim Hong-Kyu , Lee Han-Byoel , Moon Hyeong-Gon , Lee Jong Won , Han Wonshik 
Published: March 2023

Abstract
Purpose We investigated the recurrence-free survival difference between limited axillary node surgery and axillary node dissection (ALND) in clinical N0 primary breast cancer patients with one to three sentinel node metastasis who underwent total mastectomy. Method We retrospectively analyzed clinical data of 579 primary breast cancer patients who underwent total mastectomy between 2014 and 2018 from Seoul National University Hospital and Asan Medical Center. All included patients had clinical T1-2, N0 disease at the time of diagnosis based on physical exam, radiologic evaluation, and pathologic assessment if needed. The patients had one to three metastatic sentinel node(s) at the time of surgery. The patients received sentinel lymph node biopsy (SLNB) with result of one to three metastatic node(s) and either proceeded to ALND or not. We performed propensity score matching between the SLNB and ALND group with baseline clinical factors including clinical T stage and number of metastatic sentinel node(s). Finally, 208 patients were matched 1:1 for each group respectively for further analysis. Also, we stratified the eligible patients based on radiation therapy for subgroup analysis. We examined disease-free survival, regional recurrence-free survival, distant metastasis-free survival and compared the results between the groups. Result The median follow-up period was 64.7 months. Among matched cohorts, mean number of metastatic nodes on final pathology result was 1.2 for SLNB group and 1.7 for ALND group. Also, mean number of total removed nodes was 8.3 for SLNB group and 17.4 for ALND group. The disease-free survival [DFS] at 7 years was 89.7% for SLNB group and 91.1% for ALND group with no statistically significant difference. (hazard ratio [HR] 1.43, 95% confidence interval [CI] 0.70 to 2.92, p=0.32) Among patients who were treated with radiation, the DFS was 94.1% in the SLNB group and 94.4% in the ALND group. (HR, 0.82, 95% CI 0.17 to 4.0, p=0.81) For the subgroup without radiation, the DFS was 87.7% in the SLNB group and 89.4% in the ALND group. (HR, 1.68, 95% CI 0.75 to 3.75, p=0.19) We observed no statistically significant differences in the regional recurrence-free survival at 7 years (95.8% in the SLNB vs. 95% in the ALND, HR 0.62, 95% CI 0.53-4.95, p=0.39), and in the distant metastasis-free survival at 7 years (95.8% in the SLNB vs. 95% in the ALND, HR 1.28, 95% CI 0.59 to 2.73, p=0.52) Conclusion Our results suggest that limited axillary surgery with sentinel node biopsy may be as effective as axillary node dissection in terms of recurrence-free survival, for clinically node negative, primary breast cancer patients with limited metastatic sentinel node(s) who are candidates for total mastectomy. Key words: Breast cancer, Total mastectomy, Axillary lymph node dissection, Sentinel lymph node biopsy.
Citation Format: Jung Whan Chun, Hong-Kyu Kim, Han-Byoel Lee, Hyeong-Gon Moon, Jong Won Lee, Wonshik Han. Comparison of recurrence-free survival according to axillary surgery extent for clinical N0, sentinel node(s) positive, primary breast cancer patients who underwent total mastectomy. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-14-15.