Risk Factors for Disease Progression in Thermal Ablation of Papillary Thyroid Cancer-A Large-sample Analysis.

Abstract

Rationale and objectives: This study aimed to analyze risk factors influencing disease progression in patients with papillary thyroid cancer (PTC) undergoing microwave ablation (MWA).

Materials and methods: In this retrospective single-center study, 889 patients (647 women; median age, 40 years; age range, 14-80 years) who underwent MWA for PTC from June 2015 to December 2022 were enrolled. A least-absolute shrinkage and selection operator Cox regression model was employed to identify important factors for disease progression. Cox univariable and multivariable regression analyses were conducted to evaluate the association of variables with disease progression. Variables achieving statistical significance (P<0.05) were incorporated into a prognostic prediction model.

Results: The median follow-up period was 25 months. Disease progression-free survival rates at 1, 2, and 3 years were 99.6%, 97.2%, and 95.9%, respectively. Independent predictors of disease progression included multifocality (hazard ratio [HR]=2.3, 95% confidence interval [CI]: 1.2-4.3; P=0.011), ultrasound-detected extrathyroidal extension (HR=2.3, 95% CI: 1.2-4.3; P=0.010), and larger maximum diameters (HR=1.8, 95% CI: 1.1-3.0; P=0.026). Additionally, multiple tumors (HR=2.9, 95% CI: 1.4-6.0; P=0.003) and larger maximum diameters (HR=1.8, 95% CI: 1.0-3.0; p=0.038) were significantly associated with new tumor occurrence. The Cox regression fitting of the nomogram demonstrated moderate prediction efficiency (consistency index 0.715).

Conclusion: MWA is a feasible and effective treatment for patients with PTC. However, for patients with larger nodules, multiple nodules, and ultrasound-detected extrathyroidal extension, a more meticulous and precise ablation strategy is critical to minimize the risk of disease progression.