LAUSR

The Choosing Wisely guidelines were published to de-escalate surgical staging of the axilla in women >70 years of age with early invasive breast cancer. They advised against performing a sentinel lymph node biopsy (SLNB) in clinically node negative, ER+, HER2- breast cancer. Despite these guidelines, some surgeons continue to perform SLNB for adjuvant chemo/radiotherapy guidance in this cohort. A retrospective review of 347 women >70 years of age with invasive breast cancer, who underwent a SLNB between 2014 and 2022 in a single institution was performed using the Beaumont Breast Cancer Database. Data was collected on patient and tumour characteristics, subsequent management and overall survival (OS). Of 347 patients included, 91(26.22%) had a positive SLNB. 49 (14.1%) patients received chemotherapy. Of the 66 patients >80 years old, 1 received chemotherapy (1.5%). Total of 13/128(10.15%) patients (aged 75-79) and 35/153(22.9%) of patients (aged 70-74) received chemotherapy. Of 272 ER+/HER2- patients, Oncotype DX was performed in 102 patients (37.5%). From those, 17 patients had a high (>25) score (16.7%) and 10 received chemotherapy (58.8%). The remaining 86 had a low score (84.3%) and 4 received chemotherapy (4.7%). Sentinel lymph node biopsy had little influence in guiding management decisions and adjuvant therapy in patients over 80 in this study. However, we found that SLNB still had a role in patients aged 70-80 and should be used selectively in this cohort. Ongoing prospective trials will expand the increasing role of Oncotype Dx and axillary US as a replacement for SLNB.