The likelihood of additional nodal disease following a positive sentinel lymph node biopsy in breast cancer patients: validation of a nomogram

Background: Sentinel lymph node (SLN) biopsy examination is the current modality for evaluating the axilla in breast cancer patients. A nomogram has been developed to predict the likelihood of non-SLN metastases after a positive SLN biopsy examination. The purpose of this study was to validate the nomogram in a community breast center. Methods: A prospective database was used to identify breast cancer patients with a positive SLN biopsy examination who underwent a completion axillary lymph node dissection. The nomogram was used to calculate the probability of having non-SLN involvement, and was compared with the observed numbers. Results: The observed incidence of non-SLN involvement showed excellent correlation with the nomogram predicted probability (chi-square test statistic = 5.87; P = .83). Conclusions: Predicting the risk of additional nodal metastases allows the surgeon and patient to make an individualized decision regarding the need for completion axillary lymph node dissection. (c) 2006 Excerpta Medica Inc. All rights reserved.