Ava Yap1, Amy Shui2, Jessica Gosnell1, Chiung-Yu Huang2, Julie Ann Sosa1, Sanziana Roman3. 1. Division of Endocrine Surgery, Department of Surgery, University of California San Francisco (UCSF), 1600 Divisadero Street, Room A726, Box 1674, San Francisco, CA, 94143, USA. 2. Department of Epidemiology and Biostatistics, University of California San Francisco (UCSF), San Francisco, CA, USA. 3. Division of Endocrine Surgery, Department of Surgery, University of California San Francisco (UCSF), 1600 Divisadero Street, Room A726, Box 1674, San Francisco, CA, 94143, USA. Sanziana.Roman@ucsf.edu.
Abstract
INTRODUCTION: Our aim was to determine the accuracy of lymph node yield (LNY) for pediatric patients undergoing thyroidectomy with concurrent lymph nodes harvest for clinically node-negative (cN0) papillary thyroid cancer (PTC). METHODS: Patients aged ≤ 18 years with cN0 PTC undergoing thyroidectomy were reviewed in the NCDB, 1998-2016. Demographic and clinical characteristics of patients with ≥ 1 LNY were compared to those without. A truncated beta-binomial distribution estimated the number of lymph nodes needed to detect pathologic nodal positivity, and LNY was calibrated for 90% sensitivity in nodal staging and stratified across clinical tumor size staging (T). RESULTS: 1,948 children with cN0 PTC underwent surgical resection; median age was 17 years; 83.2% were female; 47.6% were T1, 25.3% T2, 9.3% T3. 1,272 (65.3%) of these patients had lymph nodes resected, or ≥ 1 LNY. The median LNY was 5 nodes (interquartile range 2-12); 45.9% of patients had ≥ 1 metastatic lymph nodes. In the overall ≥ 1 LNY cohort, 12 nodes (CI 9-19) were needed to predict nodal positivity with > 90% sensitivity. Based on clinical T-stage, detecting a metastatic lymph node with > 90% sensitivity required a LNY of 14 for T1; 8 for T2; 6 for T3. CONCLUSION: This is the first study estimating the necessary LNY for determining nodal positivity in children with cN0 PTC. The high LNY required in small T1 tumors is likely infeasible and should not be pursued. Accuracy increases with lower LNYs for higher T-stages. Our findings can help guide prognosis and treatment for pediatric patients with PTC.
INTRODUCTION: Our aim was to determine the accuracy of lymph node yield (LNY) for pediatric patients undergoing thyroidectomy with concurrent lymph nodes harvest for clinically node-negative (cN0) papillary thyroid cancer (PTC). METHODS:Patients aged ≤ 18 years with cN0 PTC undergoing thyroidectomy were reviewed in the NCDB, 1998-2016. Demographic and clinical characteristics of patients with ≥ 1 LNY were compared to those without. A truncated beta-binomial distribution estimated the number of lymph nodes needed to detect pathologic nodal positivity, and LNY was calibrated for 90% sensitivity in nodal staging and stratified across clinical tumor size staging (T). RESULTS: 1,948 children with cN0 PTC underwent surgical resection; median age was 17 years; 83.2% were female; 47.6% were T1, 25.3% T2, 9.3% T3. 1,272 (65.3%) of these patients had lymph nodes resected, or ≥ 1 LNY. The median LNY was 5 nodes (interquartile range 2-12); 45.9% of patients had ≥ 1 metastatic lymph nodes. In the overall ≥ 1 LNY cohort, 12 nodes (CI 9-19) were needed to predict nodal positivity with > 90% sensitivity. Based on clinical T-stage, detecting a metastatic lymph node with > 90% sensitivity required a LNY of 14 for T1; 8 for T2; 6 for T3. CONCLUSION: This is the first study estimating the necessary LNY for determining nodal positivity in children with cN0 PTC. The high LNY required in small T1 tumors is likely infeasible and should not be pursued. Accuracy increases with lower LNYs for higher T-stages. Our findings can help guide prognosis and treatment for pediatric patients with PTC.