Updates in systemic therapy for refractory thyroid carcinoma - targeted agents, immunotherapy, and chemotherapy.
PURPOSE OF REVIEW Systemic therapy for refractory thyroid carcinoma has moved from chemotherapy and broad multikinase inhibitors towards molecularly targeted treatment. This review summarizes recent practice-changing developments in radioiodine-refractory differentiated thyroid carcinoma, with brief updates on medullary and anaplastic thyroid carcinoma. RECENT FINDINGS Recent guidelines and clinical studies emphasize early molecular testing, and careful selection of patients for personalized systemic therapy. Lenvatinib remains the preferred first-line multikinase inhibitor for most progressive radioiodine-refractory differentiated thyroid cancers without actionable alterations, while cabozantinib is the best-supported option after lenvatinib. Selective Rearranged during transfection (RET), Neurotrophic Tropomyosin Receptor Kinase (NTRK), and Anaplastic Lymphoma Kinase (ALK) inhibitors have reshaped treatment for fusion-positive disease, and MAPK inhibition can restore radioiodine avidity in selected tumours. In anaplastic thyroid carcinoma, BRAF/MEK-directed treatment and emerging immunotherapy-targeted therapy combinations have prolonged survival and in select instances also enabled resection. SUMMARY Contemporary management of refractory thyroid carcinoma relies heavily on early molecular testing and utilizing genotype-directed targeted therapy options.