Neoadjuvant lenvatinib in a patient with invasive poorly differentiated thyroid cancer.

Background: A limited number of case reports have investigated the role of tyrosine kinase inhibitors as neoadjuvant therapy in locally invasive poorly differentiated thyroid cancer (PDTC).

Case report: A 69-year-old female patient presented with a large mass in the right thyroid lobe measuring 10 × 8 cm. A computed tomography scan showed a mass with no cleavage plane between the tumour and both the laryngotracheal and esophageal right lateral wall. A core needle biopsy was performed and confirmed PDTC. The case was considered unresectable. After a trial of neoadjuvant lenvatinib was administered, a partial response of 50% was achieved and surgery could be performed with favourable surgical outcomes. The patient did not resume lenvatinib after surgery, as no evidence of structural disease was found. At publication, she remains free of structural disease with an incomplete biochemical response.

Conclusion: Neadjuvant lenvatinib can be a therapeutic option to reduce primary tumour extent, in order to perform surgery and achieve better outcomes. However, this requires a highly selected patient group. Neoadjuvant-targeted therapy holds significant promise and warrants further investigation.