Neoadjuvant Treatment Including Targeted Therapy and Locoregional Interventions for Locally Advanced Thyroid Cancer: A Single-Center Retrospective Cohort Study.

Background: Locally advanced thyroid cancer is associated with a poor prognosis and high surgical morbidity. This study evaluated the feasibility and outcomes of neoadjuvant treatment including targeted therapy with locoregional interventions. Methods: We retrospectively analyzed 17 patients with locally advanced thyroid cancer who received neoadjuvant treatment, including tyrosine kinase inhibitors (TKIs), transarterial embolization (TAE), and radiofrequency ablation (RFA), either alone or in combination. The primary outcome was the proportion of patients who proceeded to R0 or R1 surgical resection following neoadjuvant treatment. Secondary outcomes included tumor response assessed using the Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1, and changes in surgical morbidity evaluated using the MGH/MEEI-MSK-MD Anderson surgical morbidity complexity score (MMM score) and the Invasive Thyroid Class. Results: Five patients (29%) achieved R0/R1 resection, including four with R0 resection. Most patients demonstrated reduced tumor burden and surgical complexity, as reflected by improvements in the MMM score and the Invasive Thyroid Class. The objective response rate was 47% and the 12-month progression-free survival rate was 58.2%. Conclusion: Neoadjuvant treatment may improve tumor downstaging and surgical feasibility in selected patients with initially unresectable thyroid cancer. Further prospective studies are required to validate these findings.