Retrospective study to assess axillary management and oncological outcome after neoadjuvant chemotherapy for patients with breast cancer

Intro
duction Preoperative chemotherapy (NAC) has been recognized as the standard of care for patients with locally advanced breast cancer and recently for some patients with stage II and chemoresponsive subtypes (HER2 and TNBC). Lymph node (LN) status is the most important prognostic factor in patients who receive neoadjuvant therapy. Patients who have a positive LN by fine-needle aspiration (or core needle biopsy) before neoadjuvant therapy usually undergo completion axillary dissection at the time of primary tumor resection. Axillary lymph node dissection has been the standard treatment of the axilla after NAC for many years. Sentinel lymph node biopsy (SLNB) as an alternative can reduce the extent of axillary surgery without compromising the prognostic and predictive value of axillary staging.
Aim
The aim of this work was to primarily evaluate the effect of neoadjuvant chemotherapy on axillary nodal status. The secondary objective was to evaluate the percentage of patients who are eligible for SLNB after neoadjuvant chemotherapy.
Patients
This retrospective study was conducted by collecting data during the period from October 2019 to July 2021. The study included 64 patients who had biopsy-proven locally advanced breast cancer with clinically or radiologically positive axillary LNs, had been receiving neoadjuvant chemotherapy at the Clinical Oncology Department, and underwent surgery after neoadjuvant therapy at the surgical oncology unit of Alexandria Main University Hospital. Exclusion criteria were as follows:Patients with early-stage breast cancer. Patients with metastatic stage IV breast cancer. Patients unfit for neoadjuvant therapy. Patients who refused neoadjuvant therapy. Patients aged less than 18 years or more than 75 years. Patients with clinically and radiologically negative axilla.
Methods
Data were collected retrospectively to assess the oncological and surgical outcomes after completing NAC. The files of 450 patients were reviewed, and only 64 patients were eligible patients to be included in our study.
Results
Complete pathological response (ypT0ypN0) was found in six of the 64 patients in our study. Four patients were triple-negative and two patients were HER2-enriched biological subtype. One patient was T1, one patient was T2, one patient was T3, and three patients were T4. One patient was N1, four patients were N2, and one patient was N3.
Conclusion
Post-neoadjuvant ultrasound is essential for assessment of axillary response. Approximately 44.4% of patients with negative post-neoadjuvant axillary ultrasound can avoid unnecessary ALN clearance. Accurate axillary staging is the cornerstone for omission of axillary clearance after neoadjuvant among patients.
Our recommendations
Further prospective studies with large sample sizes to assess the false-negative rate and feasibility of SLNB after neoadjuvant chemotherapy are needed. SLNB can be performed for patients showing post-neoadjuvant clinical and radiological axillary response if we can discover a technique with an acceptable false-negative rate for SLNB in post-neoadjuvant patients.