Axillary Management After Neoadjuvant Chemotherapy

Overview

The standard treatment for locally advanced and node-positive breast cancer is surgery following neoadjuvant chemotherapy (NAC). Using NAC in advanced-stage tumors and biologically aggressive subtypes can lead to de-escalation in surgical treatment for the breast and axilla. Previously, NAC was believed to alter lymphatic drainage due to fibrosis and tumor emboli in lymphatic channels. However, the theAmerican College of Surgeons Oncology Group (ACOSOG) Z1071 and Sentinel-lymph-node biopsy in patients with breast cancer before and after neoadjuvant chemotherapy (SENTINA) trials investigated the performance of sentinel lymph node biopsy (SLNB) after NAC in patients with proven axillary lymph node involvement at the initial biopsy. In contemporary breast cancer management, particularly in the axillary approach, less invasive techniques are becoming increasingly common. This raises the question of whether there might be a patient group where SLNB could be avoided. In this study, the investigators sought a new method to evaluate the axilla after NAC in patients with known axillary involvement previously. For this purpose, the investigators performed an ultrasound-guided needle biopsy on the clipped axillary lymph node with known metastasis before the planned surgery, aiming to assess the axilla without performing SLNB after treatment. Additionally, the investigators investigated which patient group might benefit more from this predictability based on molecular subtypes and clinical-pathological features.

The current study was designed as a prospective randomized clinical trial conducted at two participating centers to evaluate the predictability of sentinel lymph node biopsy (SLNB) using axillary ultrasound-guided fine-needle aspiration biopsy (FNAB) and core needle biopsy (CNB) in patients with histologically proven axillary lymph node metastasis after neoadjuvant chemotherapy (NAC). The study was initiated after obtaining approval from the local ethics committee (Dated:06.03.3023/decision no:E-10840098-772.02-1685). Patients: Female patients aged 18 years and above with clinical stage T1-3 and biopsy-proven N1 breast cancer who received NAC were included in the study. Exclusion criteria were a history of axillary surgery or SLNB, prior axillary excisional lymph node surgery, N2-3 disease with a decision for initial axillary lymph node dissection (ALND), diagnosis of inflammatory breast cancer, presence of distant metastasis, incomplete chemotherapy, pregnancy, and lactation. All participants underwent breast ultrasonography, mammography, and magnetic resonance imaging for imaging before NAC. Clipped lymph nodes that were histopathologically proven to be metastatic at the time of diagnosis underwent ultrasonography-guided CNB or FNAB seven days before surgery. Histopathological results after biopsy were grouped as negative, positive, and non-diagnostic for metastasis. Patients were randomized into two groups based on the initial biopsy method. In Group A, patients with axillary metastasis identified by FNAB were subjected to repeat ultrasound-guided FNAB after completion of neoadjuvant treatment, while in Group B, patients with axillary metastasis identified by CNB underwent repeat biopsy using the same method after completing neoadjuvant treatment. Surgical Technique and Nodal Evaluation: SLNB technique using isosulfan blue dye was performed for axillary evaluation, and all patients had the clipped lymph node excised under ultrasound guidance with a guide wire placed preoperatively. Inter-group Comparison: Sensitivity, specificity, false-negative rate (FNR), false-positive rate (FPR), and accuracy values were compared between the two groups based on the needle biopsy and SLNB performed after NAC. In patients re-evaluated with FNAB and CNB after NAC, the effects of patient age, tumor size, radiological features of breast cancer and axillary lymph node, tumor and lymph node size, histopathological type and grade of tumor, receptor characteristics, maximum standardized uptake value (SUV) of the breast and axillary lymph node on Positron Emission Tomography and Computed Tomography (PET-CT), and differences in ER, PR, Her-2, and Ki 67 receptors in the final pathology were investigated on sensitivity, specificity, FNR, FPR, and accuracy.