Evaluating the Clinical Utility of Routine Sentinel Lymph Node Biopsy and the Value of Adjuvant Chemotherapy in Elderly Patients Diagnosed With Oestrogen Receptor Positive, Clinically Node Negative Breast Cancer

Background: Sentinel lymph node biopsy (SLNB) provides staging information and guides adjuvant therapy in early breast cancer (EBC). Routine SLNB in oncogeriatricians with low-risk EBC remains controversial. Aims: To evaluate axillary management in elderly patients diagnosed with oestrogen receptor positive (ER+), clinically lymph node negative (cLN−) EBC, and to assess whether SLNB affects further axillary management or adjuvant chemotherapy (ACTX) decision making. Methods: Female patients aged > 65 years, diagnosed with ER+, human epidermal growth factor receptor-2 negative (HER2−), and cLN− breast cancer (BC), who underwent surgery and SLNB were included. Clinicopathological predictors of ACTX and completion axillary lymph node dissection (CALND) were determined. Kaplan-Meier analyses assessed survival outcomes. Results: A total of 253 patients were included (median age: 72 years, range: 66-90), all underwent SLNB; 50 (19.8%) had lymphatic metastasis on SLNB (SLNB+). Of these, 19 proceeded to CALND (38.0%), 10 (52.6%) of whom had further axillary disease (ALND+). 20 of the 50 SLNB+ patients received ACTX (40.0%) as did 31 of the 203 SLNB− patients (15.2%) (P <.001). Oncotype DX (ODX) testing was utilized in 82 cases (32.8%). Younger age (P <.001), SLNB+ (P <.001) and ODX score (P =.003) were all associated with ACTX prescription. ODX > 25 (OR: 4.37, 95% CI: 1.38-13.80, P =.012) independently predicted receiving ACTX. Receiving ACTX and proceeding to CALND did not improve disease-free (P =.485 and P =.345) or overall survival (P =.981 and P =.646). Conclusions: Routine SNLB may not be necessary in elderly patients diagnosed with ER+, cLN− EBC. Future oncogeriatric practice is likely to see genomic testing guiding ACTX prescription in this group.