The Type of Surgical Axillary Staging Following Neoadjuvant Systemic Treatment Has No Impact on Breast Cancer Patients’ Oncological Outcomes

Although response-adjusted surgery is a highly recommended strategy following neoadjuvant systemic treatment (NAST), consensus on axillary management in cN+/ycN0 breast cancer patients is still lacking. In this setting, clinical significance of the higherfalse negative rate of sentinel lymph node biopsy (SLNB) procedure is unknown. The present analysis aims to evaluate the long-term safety of the SLNB in ycN0 patients.

In this study, 60 patients with the operable breast cancer, undergoingsurgeryafter NAST in Clinical Hospital Centre Rijeka, Croatia, from May 2016 to May 2018, were included in the analysis. Following a preliminary retrospective analysis in 2019, follow-up (FU) was extended, and all outcomes were re-evaluated in December 2022.

The median FU time was 65 months and 98% of patients hadcomplete FU data. In the ypN0 group, ALND was performed for 15 and SLNB for 20 patients. The median number of LN retrieved in ALND and SLNB was 15 and 3, respectively. The method of surgical axillary staging had no impact on oncological outcomes; Regional Recurrence Free Survival Chi-square=0.5789, P=0.4467; Distant Recurrence Free Survival Chi-square=1.3658, p=0.2425; Breast Cancer Specific Survival Chi-square=0.9755, P=0.3233.

Irrespective of a higher FNR following NAST, as compared to the upfront surgery setting, SLNB is a safe procedure and should be considered for all ycN0 patients, regardless of pre-treatment cN status.