Assessment of the Memorial Sloan-Kettering Cancer Center nomogram to predict sentinel lymph node metastases in a Dutch breast cancer population.

Overview

AIM: Sentinel lymph node (SLN) biopsy is an accepted alternative to axillary lymph node dissection to assess the axillary tumour status in breast cancer patients. Memorial Sloan-Kettering Cancer Center (MSKCC) developed a nomogram to predict the likelihood of SLN metastases in breast cancer patients. Nomogram performance was tested on a Dutch population. METHODS: Data of 770 breast cancer patients who underwent successful SLN biopsy were collected. SLN metastases were present in 222 patients. A receiver operating characteristic (ROC) curve was drawn and the area under the curve was calculated to assess the discriminative ability of the MSKCC nomogram. A calibration plot was drawn to compare actual versus nomogram-predicted probabilities. RESULTS: The area under the ROC curve for the predictive nomogram was 0.67 (95% confidence interval 0.63-0.72) as compared to 0.75 in the original population. The nomogram was well-calibrated in the Dutch population. CONCLUSIONS: In a Dutch population, the MSKCC nomogram estimated risk of sentinel node metastases in breast cancer patients well (i.e. calibration) with reasonable discrimination (area under ROC curve). Nomogram performance on core needle biopsy data has to be evaluated prospectively.