Axillary lymph node dissection is not required for breast cancer patients with minimal axillary residual disease after neoadjuvant chemotherapy.

Background: Sentinel lymph node biopsy (SLNB) is widely used in patients who receive neoadjuvant chemotherapy (NAC). Still, axillary lymph node dissection (ALND) is recommended for patients with any axillary residual disease after NAC. The necessity of ALND in patients with minimal axillary disease is unclear. We aim to investigate regional recurrence rates in patients with limited axillary residual disease after NAC underwent SLNB + image-tailored axillary surgery and adjuvant radiotherapy (RT).

Methods: Patients with clinical stages were T1-3 and N1 at the time of diagnosis, clinically good or complete axillary response after NAC, and limited axillary residue (≤ 3 pathological lymph nodes) with favorable response to NAC in the final pathological examination were included in the study. All patients underwent SLNB + image-tailored axillary surgery. Peripheral lymphatic radiotherapy was applied, and no further surgery was performed in patients with compatible radiology and pathology results.

Results: Our study, which evaluated 139 patients with a median age of 47 years, found that the median number of excised lymph nodes was 4. Notably, 46% of patients had between 1 and 3 lymph nodes excised, while 45% had between 4 and 6. Only 9% of patients had ≥ 7 lymph nodes. 83(60%) of the patients underwent breast-conserving surgery (BCS), and 56(40%) underwent mastectomy. The study's median follow-up period was 44 months. During this duration, one breast recurrence (0.7%), one supraclavicular recurrence (0.7%), and six systemic recurrences (4.3%) were observed. No axillary recurrence occurred within the follow-up period.

Conclusions: Patients presenting with pathological-suspicious ≤ 3 lymph nodes on imaging and showing a good response to NAC can be considered suitable candidates for SLNB + image-tailored axillary surgery, followed by adjuvant RT instead of ALND.