American Thyroid Association Guidelines and National Trends in Management of Papillary Thyroid Carcinoma.

Importance: Over time, the American Thyroid Association (ATA) guidelines have increasingly promoted more limited treatments for well-differentiated thyroid cancers.

Objective: To determine whether the 2009 and 2015 ATA guidelines were associated with changes in the management of low-risk papillary thyroid carcinomas on a national scale.

Design, Setting, And Participants: This historical cohort study used the National Cancer Database. All papillary thyroid carcinomas diagnosed from 2004 to 2019 in the National Cancer Database were selected. Patients with tumors of greater than 4 cm, metastases, or clinical evidence of nodal disease were excluded. Data were analyzed from August 1, 2021, to September 1, 2022.

Main Outcomes And Measures: The primary aim was to tabulate changes in the rates of thyroid lobectomy (TL), total thyroidectomy (TT), and TT plus radioactive iodine (RAI) therapy after the 2009 and 2015 ATA guidelines. The secondary aim was to determine in which settings (eg, academic vs community) the practice patterns changed the most.

Results: A total of 194 254 patients (155 796 [80.2%] female patients; median [range] age at diagnosis, 51 [18-90] years) who underwent treatment during the study period were identified. Among patients who underwent surgery, rates of TL decreased from 15.1% to 13.7% after the 2009 guidelines but subsequently increased to 22.9% after the 2015 changes. Among patients undergoing TT, rates of adjuvant RAI decreased from 48.7% to 37.1% after 2009 and to 19.3% after the 2015 guidelines. Trends were similar for subgroups based on sex and race and ethnicity. However, academic institutions saw larger increases in TL rates (14.9% to 25.7%) than community hospitals (16.3% to 19.5%). Additionally, greater increases in TL rates were observed for tumors 1 to 2 cm (6.8% to 18.9%) and 2 to 4 cm (6.6% to 16.0%) than tumors less than 1 cm (22.8% to 29.2%).

Conclusions And Relevance: In this cohort study among patients with papillary thyroid carcinomas up to 4 cm, ATA guideline changes corresponded with increased TL and reduced adjuvant RAI. These changes were primarily seen in academic institutions, suggesting an opportunity to expand guideline-based care in the community setting.