Predictors of Pathologically Negative Sentinel Lymph Nodes and Recurrence-Free Survival in Women with Invasive Breast Cancer Treated with Neoadjuvant Chemotherapy.

BACKGROUND

The accuracy and safety of sentinel lymph node (SLN) dissection (SLND) have not been established for women with invasive breast cancer (BC) who underwent neoadjuvant chemotherapy (NAC). The purpose of this study was to identify factors that predict pathologically negative axillary lymph node (ALN) status and recurrence-free survival (RFS) in women with invasive BC and clinically negative ALN after NAC followed by SLND.

METHODS

The analysis included patients with BC (T1-4, N0-1, M0) treated with NAC who had clinically negative ALNs after NAC followed by SLND between January 2018 and May 2022. Age, clinical tumor size, clinical ALN status, estrogen receptor (ER), progesterone receptor, human epidermal growth factor receptor 2 (HER2), molecular subtype, histological grade, Ki67, all at baseline, and pathologic tumor size after NAC were analyzed for correlations with pathological ALN metastasis and RFS.

RESULTS

SLND identified at least one SLN (blue or radioactive node) in all of 112 consecutive patients. Multivariable analysis showed that age >50 years, clinically negative ALN, histologic grade II or III, ER negativity, triple negative subtype (all at baseline), and pathologically invasive tumor size of ≤2.0 cm after NAC showed a significant correlation with pathologically negative ALN. HER2 positivity and pathological complete response of the primary tumor were significantly correlated with favorable RFS.

CONCLUSIONS

These predictors of pathologically negative ALN and RFS after NAC are useful for planning appropriate surgical and adjuvant treatment for BC patients.