Axillary staging prior to or after neoadjuvant systemic therapy? A single institutional experience

Background: The study aim was to investigate our institutional strategies for axillary staging in breast cancer patients undergoing neoadjuvant therapy. Methods: We identified 595 patients treated with neoadjuvant therapy between 2000 and 2007. Axillary staging occurred by four methods: (1) pre-therapy fine needle aspiration biopsy (FNAB); (2) pre-therapy sentinel lymph node biopsy (SLNB); (3) post-therapy SLNB; or (4) post-therapy axillary lymph node dissection (ALND). Results: Of 595 patients, 115 underwent FNAB (Group 1; 36 N0, 79 N+), 88 underwent SLNB pre-therapy (Group 2; 47 N0, 41 N+), 55 underwent SLNB post-therapy (Group 3; 42 N0, 13 N+), and 337 underwent ALND post-therapy (Group 4; 133 N0, 204 N+). There was no difference between groups according to patient age, race, stage of disease, estrogen/progesterone receptor and Her-2neu status, or type of neoadjuvant therapy. Conclusions: The lack of standardized recommendations for axillary staging in the setting of neoadjuvant therapy leads to variable approaches within an institution. The use of ALND without pre-therapy axillary assessment may result in over-treatment of patients. Randomized clinical trials are needed to determine the feasibility and accuracy of SLNB following neoadjuvant therapy. Until such data are available, pre-therapy axillary staging may reduce the number of unnecessary lymph node dissections.