Prediction of nonsentinel lymph node metastasis in sentinel node-positive breast carcinoma

The incidence of nonsentinel (NSN) lymph node metastases in patients with a tumor-positive sentinel (SN) lymph node varies greatly from 20% to 70% in the published literature. Current practice is that most patients with a positive SN (micro- and macrometastases) undergo a complete axillary dissection. However, it has been shown by other investigators that a large number of patients with a positive SN do not necessarily need a complete axillary dissection. In this analysis, we reviewed the pathology slides from 58 patients who had undergone SN and axillary node dissection. The tumor size, histologic parameters, receptor (estrogen and progesterone), and HER-2neu oncoprotein expression were noted. Student t test and Fisher exact test were used for statistical analysis. Of 58 patients, 19 (32.7%) had NSN metastases. Primary tumor size (P < .002), size of SN metastatic tumor (P < .03), and the presence of extracapsular tumor extension (P < .0001) were associated significantly with NSN metastases. We have shown in this study that it would be possible to predict the NSN status based on primary tumor size, size of SN metastatic tumor, and presence of SN extracapsular tumor extension.