Management of the axilla in postmenopausal patients with cN0 hormone receptor-positive/ HER2-negative breast cancer treated with neoadjuvant endocrine therapy and its prognostic impact.

Abstract

Abstract Purpose To evaluate the differences when performing the sentinel lymph node biopsy (SLNB) before or after neoadjuvant endocrine therapy (NET) in breast cancer patients, and the impact of its timing on prognosis. Methods A retrospective cohort study including 91 postmenopausal cases with clinically node-negative and hormone receptor-positive/HER2 negative (HR+/HER2-) breast cancer, treated with NET and SLNB at our institution. SLNB was performed pre-NET until 2014, and post-NET thereafter. Axillary lymph node dissection (ALND) was indicated only in SLNB-macrometastasis, although in selected elderly patients it was omitted. Kaplan-Meier survival curves were obtained in relation to the status of the axilla, and the differences assessed using the log-rank test. Results Between December 2006 and March 2022, SLNB was performed pre-NET in 14 cases and post-NET in 77. SLNB-positivity was similar regardless of whether SLNB was performed before or after NET (35.7% and 37%, respectively), with 2/14 SLN macrometastases in the pre-NET cohort and 17/77 in the post-NET cohort. Only three patients (18.7%) with SLN macrometastasis had > 3 positive nodes following axillary node dissection. The 5-year overall survival and distant disease-free survival were 92.4% and 94.8% respectively, with no significant differences according to SLNB status. Conclusion SLN positivity did not differ according to its timing (before or after NET). Therefore, NET has no effect on lymph node clearance. Furthermore, the prognosis is good regardless of the axillary involvement. Therefore, factors other than axillary involvement may affect the prognosis in these patients.