Value of Memorial Sloan-Kettering Cancer Center nomogram in clinical decision making for sentinel lymph node-positive breast cancer

Background: The aim of this study was to determine the value of the Memorial Sloan-Kettering Cancer Center (MSKCC) nomogram for individual decision making in a Dutch cohort of women with breast cancer with a positive sentinel lymph node (SLN) but at low risk of additional nodal metastases. Methods: Data were collected on 168 patients with a positive SLN who underwent completion axillary lymph node dissection. The predicted probability of non-SLN metastases was calculated for each patient, using the MSKCC nomogram. Specificity and false-negative rates were calculated for subgroups with a predicted risk of no more than 5, 10 or 15 per cent. A receiver operating characteristic (ROC) curve was constructed and the area under the curve (AUC) calculated. Results: The discrimination of the MSKCC nomogram, measured by the AUC, was 0.68. For low predicted probability cut-off values of no more than 5, 10 and 15 per cent, the false-negative rates were 20, 14 and 19 per cent, and the specificities were 4, 27 and 32 per cent, respectively. The low-risk category (5 per cent or less) consisted of only 3.0 per cent of the study population. Conclusion: The performance of the MSKCC nomogram was insufficient to make it a useful tool for individual decision making in this cohort of women with SLN-positive breast cancer.