Aims: This study evaluates the breast cancer nomogram (BCN), an online tool developed by Memorial Sloan-Kettering Cancer Center to determine the rate of non-SLN positivity, in an independent cohort of SLN positive patients.
Material and methods: Available data between 02/2000 and 06/2004 in two prospective databases, 749 cases had successful SLN biopsy including 149 axillary-SLN metastases study cases. These cases had accurately graded tumours up to 9 cm in size and CAD with a minimum total 10 nodes removed. Histopathological assessment of nodes included hematoxylin and eosin staining and/or immunohistochemistry. Computerized BCN was used to estimate probability of non-SLN positivity and compared with actual probability after grouping into deciles.
Results: The trend of actual probability in various decile groups was comparable to the predicted probability. An area under the receiver operating characteristic curve was 0.75 as compared to 0.76 in the original study.
Conclusion: Although this study is small, the results are encouraging and suggest the nomogram is a useful tool to estimate the likelihood of positive axillary non-SLN. However, variations in pathological assessment between centres are the major impediment to widespread application of BCN. If SLN positive patients decline the standard recommendation of CAD or entry into clinical trials evaluating the significance of CAD then the BCN could help in decision making.