Validation of Three Breast Cancer Nomograms and a New Formula for Predicting Non-sentinel Lymph Node Status

Background: The aim of the study was to evaluate the available breast nomograms (MSKCC, Stanford, Tenon)to predict non-sentinel lymph node metastasis (NSLNM) and to determine variables for NSLNM in SLN positivebreast cancer patients in our population. Materials and
Methods: We retrospectively reviewed 170 patientswho underwent completion axillary lymph node dissection between Jul 2008 and Aug 2010 in our hospital. Wevalidated three nomograms (MSKCC, Stanford, Tenon). The likelihood of having positive NSLNM based onvarious factors was evaluated by use of univariate analysis. Stepwise multivariate analysis was applied to estimatea predictive model for NSLNM. Four factors were found to contribute significantly to the logistic regressionmodel, allowing design of a new formula to predict non-sentinel lymph node metastasis. The AUCs of the ROCswere used to describe the performance of the diagnostic value of MSKCC, Stanford, Tenon nomograms and ournew nomogram.
Results: After stepwise multiple logistic regression analysis, multifocality, proportion of positiveSLN to total SLN, LVI, SLN extracapsular extention were found to be statistically significant. AUC results wereMSKCC: 0.713/Tenon: 0.671/Stanford: 0.534/DEU: 0.814.
Conclusions: The MSKCC nomogram proved to bea good discriminator of NSLN metastasis in SLN positive BC patients for our population. Stanford and Tenonnomograms were not as predictive of NSLN metastasis. Our newly created formula was the best predictiontool for discriminate of NSLN metastasis in SLN positive BC patients for our population. We recommend thatnomograms be validated before use in specific populations, and more than one validated nomogram may beused together while consulting patients.