Clinicopathological Factors and Nomograms Predicting Non Sentinel Lymph Nodes Metastases after Neoadjuvant Chemotherapy in Breast Cancer Patients.

Abstract Background : Studies have demonstrated the feasibility and accuracy of sentinel lymph node (SLN) biopsy after neoadjuvant chemotherapy (NAC) in breast cancer. Some SLN-positive patients have low risk of non-sentinel lymph node (non-SLN) involvement. The aim of the present study performed on this group of SLN-positive patients after NAC was to determine clinicopathological factors associated with non-SLN involvement and to test scoring systems predicting the risk of additional nodal metastases currently available for SLN-positive patients not treated with NAC.Patients and methods : Patients with infiltrating breast carcinoma (n= 132) were studied prospectively. All patients received NAC. At surgery, SLN biopsy followed by axillary lymph node dissection was performed. Lymphatic mapping was done using the isotope method. Fifty-one patients were SLN positive.Results : In univariate analysis, tumor size more than 26 mm (P= 0.016) and the size of SLN metastases more than 2 mm (P= 0.0055) were significantly correlated with the presence of non-SLN metastases. In multivariate analysis, SLN macrometastases conferred a 10.2-fold greater risk of non-SLN positivity than SLN micrometastases (P= 0.047, 95%-confidence interval, 1.15-90.2). The Memorial Sloan-Kettering Cancer Center nomogram was not reliably predictive for non-SLN metastases (AUC, area under the receiver operating characteristic curve, of 0.542), whereas the MD Anderson (AUC= 0.716) and Tenon scoring systems (AUC= 0.778) were validated.Conclusion: Our results suggest that clinicopathological factors predicting non-SLN involvement in SLN-positive patients with and without NAC are essentially the same. The risk of involvement may be assessed using existing nomograms, but additional large prospective studies are needed to determine their accuracy in patients after NAC. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1011.