Are Nomograms Useful in Predicting Upstage From Ductal Carcinoma In Situ to Invasive Carcinoma Requiring Sentinel Lymph Node Biopsy

The upstage rate from ductal carcinoma in situ (DCIS) on core biopsy to invasive carcinoma at definitive excision ranges from 20 to 30%. Nomograms have been developed to aid in the prediction of upstaging so as to guide surgical planning with respect to performance of sentinel lymph node biopsy (SLNB). The aim of this study was to evaluate the ability of these nomograms to predict upstaging within our public hospital population. A retrospective review of patients with DCIS from 2013 to 2018 at a single institution was performed. Individualized probability of upstage was calculated using the Samsung Medical Center (SMC) and Annals of Surgical Oncology (ASO) nomograms. Areas under the receiver operating characteristic curves were calculated to assess the discriminative power of each. Of 105 patients with DCIS, 31 (29.5%) were upstaged to invasive disease. The SMC and ASO nomograms demonstrated area under the curves (AUCs) of .65 (OR = 1.023, 95% CI 1.004-1.042, P = .02) and .60 (OR = 1.035, 95% CI 1.003-1.068, P = .03), respectively. While SMC provided greater discrimination in our cohort, the performance of these nomograms as reliable clinical adjuncts to guide SLNB decision-making in this cohort was less than optimal and thus should not be the sole factor in determining individual upstage risk.