Impact of sentinel lymph node biopsy on management of older women with clinically node-negative, early-stage, ER+/HER2−, invasive breast cancer: a systematic review and meta-analysis

In 2016 the Choosing Wisely guidelines advised against routine performance of a sentinel lymph node biopsy (SLNB) in women ≥ 70 years of age with clinically node negative (cN0), early-stage, oestrogen receptor positive/ human epidermal growth factor receptor 2 negative (ER+/HER2-), invasive breast cancer. The argument in favour of its continued performance is that it may serve as a useful guide for subsequent management. This systematic review was performed in accordance with the PRISMA guidelines. Studies reporting on rate of adjuvant chemotherapy, adjuvant radiotherapy and performance of completion axillary lymph node dissection (cALND) post SLNB in women aged ≥ 65 years with cN0, early-stage, ER+/HER2-, invasive breast cancer were included. A random effects meta-analysis was performed with summary estimates made using the Mantel-Haenszel method. Dichotomous outcomes were reported as odds ratios (ORs) with 95% confidence intervals (CIs). Ten retrospective studies across 4 countries. Of 105,514 patients, 15,509 had a positive SLNB and 90,005 had a negative SLNB. On meta-analysis, a positive SLNB was significantly associated with receipt of adjuvant chemotherapy (OR 4.64 (95% CI 3.18, 6.77), P < .00001), adjuvant radiotherapy (1.71 (95% CI 1.18, 2.47), P = .005) and undergoing completion axillary lymph node dissection (OR 68.97 (95% CI, 7.47, 636.88), P = .0002). Adjuvant treatment decisions continue to be influenced by SLNB positivity in the era of the Choosing Wisely guidelines. The effects of a positive SLNB and subsequent treatments on outcomes remain inconclusive. However, it is likely clinicians are continuing to over-investigate and over-treat this cohort.