P3-07-35: Validation of Online Calculators To Predict Non-Sentinel Lymph Node Status in Sentinel Lymph Node-Positive Breast Cancer Patients.

Abstract

Abstract Purpose: Axillary lymph node dissection (ALND) is recommended for breast cancer patients with sentinel lymph node (SLN) metastasis, but further nodal disease is not always present. Several models exist for predicting non-sentinel lymph node (non-SLN) metastasis in SLN metastasis. This study evaluated and compared the predictive values of the Memorial Sloan-Kettering Cancer Center (MSKCC) nomogram and the Stanford nomogram, which were conveniently available online, and clarified their usefulness for the micrometastasis or isolated tumor cell (ITC) subgroup. Methods: Data from 89 patients with positive SLN biopsy who underwent ALND were used, including 59 patients with macrometastasis and 30 with micrometastasis/ITC. The predicted probability of non-SLN metastasis was calculated using a computerized model from the websites for each nomogram. Results were compared using area under the curve (AUC) of the receiver operating characteristics curve for each model. False-negative and false-positive rates were also calculated. Results: AUC for the entire population was 0.701 with the MSKCC nomogram and 0.756 with the Stanford nomogram. AUCs of macrometastasis and micrometastasis/ITC were 0.680 and 0.469 with the MSKCC nomogram and 0.676 and 0.574 with the Stanford nomogram, respectively. Conclusions: This independent comparison found no significant difference between the two nomograms. In our results, these nomograms could not reliably predict positive non-SLN in cases with SLN micrometastasis/ITC. Further validation in other patient populations is needed. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-07-35.