Clinical experience in the neoadjuvant treatment of unresectable differentiated thyroid cancer with the lenvatinib

Introduction. In some cases of differentiated thyroid cancer expansion into the main vessels and adjacent organs, surgical intervention is impossible. Not many cases of successful use of targeted therapy as neoadjuvant regimen to treat nonresectable differentiated thyroid cancer were reported, but this approach can be an option in management of such patients.Aim. To analyze clinical experience of using lenvatinib as neoadjuvant therapy in patients with primary nonresectable differentiated thyroid cancer.Materials and methods. Retrospective analysis of treatment of 7 patients with primary nonresectable differentiated thyroid cancer with lenvatinib as neoadjuvant therapy at Chelyabinsk Regional Clinical Center for Oncology and Nuclear medicine between 2021 and 2023 was performed.Results. Treatment response was evaluated in 4 (71.4 %) patients. In 2 (50 %) patients, partial response was observed, in 2 - stable disease. Radical surgical intervention became possible in 2 patients. The other 2 patients could not undergo surgery: in 1 patients time to progression was 17.8 months, therapy was changed to the 2nd line drug cabozantinib; 1 female patient with best response (partial) currently continues lenvatinib treatment, tumor is nonresectable, duration of drug administration is 8.9 months.Conclusion. Our experience of using lenvatinib in patients with nonresectable differentiated thyroid cancer shows that this therapy can be successfully used as neoadjuvant treatment in this patient group.