Does sentinel lymph node biopsy influence subsequent management decisions in women with breast cancer ≥70 years old?

Background There 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 SLNB is that it may guide subsequent management. Methods A 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 tumour characteristics and subsequent management for all patients and for patients with ER+/HER2-, early-stage disease. Results Positive SLNB significantly increased likelihood of receiving adjuvant chemotherapy (CTh) in patients aged 70-75 in all clinical subtypes (OR 4.0, 95% c.i.1.6 to 10; P = 0.0035). 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% c.i. 3.00 to 455.2; P= 0.0103). Positive SLNB was significantly associated with receiving adjuvant radiotherapy (RTh) in all patients aged 70-75 (OR 4.5, 95% c.i. 2.0 to 11; P = 0.0004) and 75-80 (OR 9.7, 95% c.i. 2.7 to 46, P = 0.0015). In patients aged ≥80 years, positive SLNB did not have a significant influence on subsequent treatments. Conclusion In 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. Microabstract Recent guidelines advise the de-escalation of sentinel lymph node biopsy (SLNB) in select patients ≥70 years of age with invasive breast cancer. However, this retrospective study observed that positive SLNB was significantly associated with receiving chemotherapy in patients aged 70-75, and adjuvant radiotherapy in patients aged 70-80. SLNB did not influence subsequent management of patients aged ≥80 years.