The aim of our study was to determine the number of sentinel nodes (SN) and non-sentinel nodes (NSN) involved and to identify predictive factors of non-sentinel lymph node involvement in breast cancer patients.
The analysis was performed retrospectively on 1350 patients referred for sentinel lymph node biopsy (SLNB) during the 5-year period 2010–2014.
Metastatic involvement of SN was found in 286 patients (21 %). A subgroup of 274 (96 %) patients, of whom 90 (33 %) had NSN involvement, underwent axillary lymph node dissection (ALND). A prediction model was developed using the significant predictors detected by the univariate analysis.
The most important predictive factors of NSN involvement were the ratio of positive-to-removed SN, size of metastases and a tumour lympho-vascular invasion (LVI). The model may serve to optimize treatment strategies for patients presenting more of the identified risk factors for NSN involvement.