Successful Salvage of Four Cases of Unresectable Papillary Thyroid Cancer Following Lenvatinib Administration.

Background/aim: The role of lenvatinib as neoadjuvant chemotherapy for patients with advanced thyroid cancer has not been firmly established. In some cases, surgery may be considered when lenvatinib treatment becomes challenging to continue.

Case report: We present four cases of unresectable thyroid cancer diagnosed histologically as papillary carcinoma. The patients were a 61-year-old female (T4aN1bM0), a 75-year-old male (T4aN1bM0), a 61-year-old female (T3N1bM0), and a 64-year-old female (T4aN1bM0). Initial lenvatinib doses were 24, 10, 24, and 14 mg/day, respectively. The treatment administration periods were 8, 29, 3, and 6 months, with final doses of 4, 4, 10, and 14 mg/day, respectively. Tumors had primarily invaded the surrounding tissues, mainly the common carotid artery, and were considered unresectable. After lenvatinib administration, tumor shrinkage was observed. Despite complications from lenvatinib that resulted in difficulty in the administration of the drug, successful tumor resection was achieved, and local control was achieved in all patients.

Conclusion: Preoperative lenvatinib treatment may offer a less invasive alternative for advanced thyroid cancer cases that would otherwise require invasive surgery.