Number of metastatic sentinel nodes as predictor of axillary involvement in patients with breast cancer

Background and objectives. More than half of patients with positive sentinel node (SN) have no metastases in non-sentinel nodes (NSNs) on axillary lymph node dissection (ALND). The aim of this study was to investigate factors predictive of NSNs involvement, in order to identify patients with metastatic disease confined to the SN which might avoid ALND. Methods. ALND was performed in 167 patients with metastatic SN. Axillary NSNs status was correlated with the size of SN metastases, the size of the primary tumor and the occurrence of lymphovascular invasion. In 72 cases, the radiotracer (Tc-99m albumin colloid) marked multiple (in most cases 2 or 3) nodes. In this group, NSNs status was correlated with the number of metastatic radioactive nodes (1 or >1), and with the above mentioned histopathologic factors. Results. NSNs metastases were found in 57/167 cases (34.1%), the rate increasing proportionate to the size of both SN metastases (p <0.0001) and primary tumor (p = 0.0075), while no significant correlation was found for lymphovascular invasion (p = 0.1769). At univariate and multivariate analysis of findings from the 72 cases with multiple probe-detected hot nodes, positivity in more than one hot node was the strongest predictor of NSN involvement (p = 0.0019). Conclusions. The identification and excision of multiple hot nodes can be useful in the prediction of NSNs involvement in patients with metastatic SN.