BackgroundThere have been ongoing attempts to de-escalate surgical intervention in older breast cancer patients in recent years. However, there remains ongoing hesitancy amongst surgeons to de-implement axillary staging in this cohort. The supporting argument for performing a sentinel lymph node biopsy (SLNB) is that it may guide subsequent management. MethodsA retrospective review was performed of 356 SLNBs, in 342 women ≥ 70 years of age with invasive breast cancer, between 2014 and 2022 in a single institution. Data were collected on patient and tumor characteristics and subsequent management for all patients and for patients with ER+/HER2-, early-stage disease. ResultsPositive SLNB significantly increased likelihood of receiving adjuvant chemotherapy (CTh) in patients aged 70-75 in all clinical subtypes (OR 4.0, 95% CI, 1.6-10; P = .0035). Positive SLNB did not significantly increase likelihood of receiving adjuvant CTh in patients aged 75-80, however, an Oncotype Dx score of ≥ 26 did (OR 34.50, 95% CI, 3.00-455.2; P = .0103). Positive SLNB was significantly associated with receiving adjuvant radiotherapy (RTh) in all patients aged 70-75 (OR 4.5, 95% CI, 2.0-11; P = .0004) and 75-80 (OR 9.7, 95% CI, 2.7-46; P = .0015). In patients aged ≥ 80 years, positive SLNB did not have a significant influence on subsequent treatments. ConclusionIn this study, SLNB did not significantly influence subsequent management decisions in patients over 80 and should rarely be performed in this cohort. However, SLNB still had a role in patients aged 70-80 and should be used selectively in this cohort.