Nomograms for predicting sentinel lymph node metastasis in melanoma in a Southern Brazilian population: an accuracy study.

INTRODUCTION

Sentinel lymph node biopsy is fundamental for staging and prognostication of cutaneous melanoma when indicated. However, it still yields a high rate of negative results. To reduce the rate of true negatives, oncology centers have developed nomograms to better stratify patients for whom the procedure is recommended.

OBJECTIVE

To study the accuracy of two nomograms developed by the Memorial Sloan-Kettering Cancer Center (MSKCC) and the Melanoma Institute Australia (MIA) for calculating the probability of sentinel lymph node positivity in a population of patients from southern Brazil.

METHODS

An accuracy study was conducted, including data from 320 patients diagnosed with melanoma at a referral oncology institution in Santa Catarina, Brazil. The risk of sentinel lymph node positivity was calculated for each patient using the studied nomograms and compared to the results of histopathological examination. Discrimination was assessed by calculating the area under the Receiver Operating Characteristic (ROC) curve, thereby determining the accuracy of each nomogram.

RESULTS

The MSKCC nomogram demonstrated an overall accuracy of 69.05%, while the MIA nomogram showed an accuracy of 68.38%.

CONCLUSION

The nomograms did not exhibit acceptable levels of accuracy for application in the studied population.