Comparative Performance of the 2015 and 2025 American Thyroid Association Initial Recurrence Risk Stratification
Weixun Ke1, Xuanling Zheng2,3, Liying Wang2,3
1The Graduate School of Fujian Medical University, Fuzhou, China.
Background:
The 2025 American Thyroid Association (ATA) guidelines introduced significant modifications to the initial risk stratification system for differentiated thyroid cancer (DTC). However, the real-world prognostic performance and stage migration effects of these updates compared with the 2015 system remain unevaluated.
Methods:
We conducted a retrospective cohort study at a tertiary referral center in China. Adult patients who underwent initial thyroidectomy for pathologically confirmed DTC between January 2008 and December 2018 were included, with follow-up extending through October 30, 2025. We compared the 2015 and 2025 ATA initial risk stratification systems. The primary outcome was structural disease-free survival (SDFS). Performance was assessed using area under the receiver operating characteristic curve (AUC), reclassification analysis, and decision curve analysis (DCA).
Results:
Among 1508 patients (median age 43 years, interquartile range [IQR] = 33-53; 1147 [76.1%] female), 120 (8.0%) developed events during a median follow-up of 8.9 years (IQR = 7.56-10.80). The 2025 ATA system demonstrated superior discrimination compared with the 2015 system (ΔAUC 0.0455 [confidence interval or CI: 0.0147-0.0764], p = 0.004), although both systems showed significant risk stratification (log-rank p < 0.001). Reclassification analysis revealed that the 2025 system reassigned 41.7% of patients with recurrence to higher-risk categories but also reassigned 38.8% of recurrence-free patients to higher-risk categories. Multivariable analyses identified the revised multifocality criteria and the presence of two or more low-to-intermediate risk features as the major contributors to this reclassification (risk inflation). Conversely, refined compartment-based lymph node stratification was associated with improved classification accuracy. DCA demonstrated greater net clinical benefit for the 2025 system across clinically relevant threshold probabilities.
Conclusions:
The 2025 ATA initial risk stratification system significantly improves prognostic discrimination compared with the 2015 system. However, the enhanced sensitivity comes with a specificity trade-off, leading to substantial upward risk reclassification for recurrence-free patients. These real-world findings provide critical insights for clinicians to balance intensified surveillance against the potential for overtreatment under the new guidelines.