Evaluation of the Role of Axillary Lymph Node Fine-Needle Aspiration Cytology in Early Breast Cancer With or Without Neoadjuvant Chemotherapy.

Purpose: Fine-needle aspiration cytology (FNAC) of axillary lymph nodes (AxLNs) is performed to diagnose nodal metastasis in patients with breast cancer. Although the sensitivity of ultrasound-guided FNAC for identifying AxLN metastasis is in the range of 36%-99%, whether sentinel lymph node biopsy (SLNB) should be performed for neoadjuvant chemotherapy (NAC) patients with negative FNAC results is uncertain. This study aimed to determine the role of FNAC before NAC in the evaluation and management of AxLN in early breast cancer patients.

Methods: We retrospectively analyzed 3,810 clinically node-negative (a lymph node with no clinical metastasis without FNAC or radiological suspicion of metastasis with negative FNAC results) patients with breast cancer who underwent SLNB between 2008 and 2019. We compared the positivity rate of sentinel lymph nodes (SLNs) between patients who received and those who did not receive NAC with negative FNAC results or without FNAC and axillary recurrence rate in the neoadjuvant group with negative SLNB results.

Results: In the non-neoadjuvant (primary surgery) group, the positivity rate of SLNs in patients with negative FNAC results was higher than that in patients without FNAC (33.2% vs. 12.9%; p < 0.001). However, the SLN positivity rate of patients with negative FNAC results (false-negative rate for FNAC) in the neoadjuvant group was lower than that in the primary surgery group (3.0% vs. 33.2%; p < 0.001). After a median follow-up of 3 years, one axillary nodal recurrence was observed, which was a case from the neoadjuvant non-FNAC group. None of the patients in the neoadjuvant group with negative FNAC results had axillary recurrence.

Conclusion: The false-negative rate for FNAC in the primary surgery group was high; however, SLNB was the proper axillary staging procedure for NAC patients who have clinically suspicious AxLN metastases on radiologic examination but negative FNAC results.