Validation of Memorial Sloan Kettering Cancer Center nomogram to detect non-sentinel lymph node metastases in a United Kingdom cohort.

Abstract

Axillary lymph node dissection, although associated with long-term morbidity, has been the standard of treatment for all nodepositive breast cancer patients. We assessed the risk prediction ability (validity) of Memorial Sloan Kettering Cancer Center (MSKCC) nomogram for non-sentinel lymph node metastases and analysed the outcome of patients with sentinel node metastases. All operable early breast cancer patients with sentinel node macro metastases (size > 2mm) who underwent axillary dissection from April 2009 to March 2015 were considered eligible. The risk of non-sentinel lymph node metastases was calculated using an online MSKCC calculator, and accuracy was determined based on the area under the receiver-operating characteristic curve (AUC-ROC). Tumour characteristics and overall survival were also analysed as secondary end points. Of 1745 patients who were diagnosed with operable breast cancer during the study period, 114 patients were considered eligible. The AUC-ROC was 0.66 suggestive of lesser accuracy in prediction and not statistically significant (p value = 0.7303). Seventysix (50.7%) of these patients did not have any non-sentinel node metastases. At a mean follow up of four years, the disease-free survival was 86.4% and overall survival rate was 88.4%. The MSKCC nomogram was unable to accurately predict the risk in our cohort of patients with more than half of this cohort of patients not requiring axillary dissection. These findings are consistent with other European studies. This study thus highlights the need for modified prediction model for European cohorts.