Abstract PO5-02-12: Comparison of survival outcomes according to axillary ultrasonography findings and cytology results in early-stage breast cancer patients

Abstract Purpose: Axillary lymph node dissection and sentinel lymph node biopsy are associated with increased risk of post-surgical complications including lymphedema and recent trials have raised questions about the therapeutic benefit of axillary operation in early-stage breast cancer patients. While treatment options for lymph nodes with negative findings on axillary ultrasonography (AUS) or positive findings on fine needle aspiration biopsy (FNAB) are evident, data regarding lymph nodes that are suspicious on AUS but negative by FNAB are limited. Thus, we aimed to compare clinicopathological characteristics of AUS positive and FNAB negative patients with those of AUS negative or FNAB positive patients. Materials and Methods: Medical records of patients who underwent breast cancer surgery between January 2010 and December 2017 were reviewed. Patients were grouped into the following three groups: (a) negative findings on AUS, (b) suspicious findings on AUS but negative on FNAB, (c) and FNAB positive. A total of 4,506 patients were included for analysis, with 3,771 patients with no suspicious lymph nodes on AUS, 557 patients who had suspicious AUS findings but were negative on FNAB, and 178 patients with positive findings on both AUS and FNAB. Primary endpoints were disease free survival (DFS) and recurrence free survival (RFS), and secondary endpoint was overall survival (OS). Results: At a median follow-up period of 92 months, DFS and RFS was significantly higher in the AUS negative group compared to the other two groups (10-year-DFS: 91.6% vs 87.5% vs 75.7%, 10-year-RFS: 95.0% vs 89.9% vs 77.1%, p 0.001). In terms of OS, AUS negative group and the AUS positive and FNAB negative group did not show statistically significant survival difference (10-year-OS: 94.5% vs 92.8%, p = 0.061), while the FNAB positive group showed significantly lower survival rates (10-year-OS: 81.8%, p 0.001). Multivariable analysis revealed that not AUS positive and FANB negative but positive FNAB was significantly associated with poor RFS. Moreover, hormone receptor (HR) positive and HER2 negative subtype showed poor DFS and RFS in subgroup analysis. Conclusion: Early breast cancer patients with suspicious findings on AUS but negative FNAB results had similar OS but inferior DFS and RFS compared to those with negative features on AUS, especially in HR(+)HER2(-) subtype. While further prospective trials are warranted to determine whether additional treatment is necessary, close surveillance is recommended for this subgroup of patients. Figure1. Overall survial and Disease free survival according to axillay US and FNAB status Table1. patients' characteristics Table2. prognostic factors for overall survival and disease free survival related to axillary US and FNAB status Citation Format: Suk Jun Lee. Comparison of survival outcomes according to axillary ultrasonography findings and cytology results in early-stage breast cancer patients 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 PO5-02-12.