Disparities in Adjuvant Radioactive Iodine Use in High-Risk Follicular Thyroid Carcinoma: Evaluation of NCCN and ATA Guideline Concordance.

INTRODUCTION

Radioactive iodine (RAI) therapy is recommended for high-risk follicular thyroid carcinoma (FTC). However, factors influencing its use remain poorly defined. This study evaluated predictors of RAI use and outcomes among high-risk FTC patients using 2015 American Thyroid Association (ATA) and National Comprehensive Cancer Network (NCCN) classifications.

MATERIALS AND

METHODS

The National Cancer Database was queried for adults with FTC who underwent thyroidectomy between 2004 and 2022. Patients were classified as high risk based on 2015 ATA and NCCN criteria. Multivariable logistic and Cox regression models assessed predictors of RAI use and overall survival.

RESULTS

Among 7943 FTC patients, 6411 (80.7%) were classified as high risk by NCCN and 7466 (94.0%) by ATA criteria. RAI was administered to 67.7% (NCCN) and 67.8% (ATA) of high-risk patients. Hispanic (ATA odds ratio [OR], 0.77; NCCN OR, 0.76) and Asian (ATA OR, 0.72; NCCN OR, 0.76) patients had lower odds of RAI receipt. Positive margins, T3-T4 tumors, and total thyroidectomy were associated with greater RAI use. RAI was linked to reduced mortality in both NCCN (hazard ratio 0.74) and ATA (hazard ratio 0.74) cohorts. Black race, Medicaid insurance, and poorly differentiated tumors were independently associated with increased mortality, along with T4 stage and distant metastases.

CONCLUSIONS

RAI is associated with improved survival in high-risk FTC, yet disparities by race and insurance status persist. These findings highlight the need to improve equitable access to guideline-concordant treatment in high-risk populations.