CLINICAL EFFICACY AND SAFETY OF VANDETANIB IN METASTATIC MEDULLARY THYROID CARCINOMA: A CASE REPORT

Background: Medullary thyroid carcinoma is a rare neuroendocrine malignancy characterized by variable clinical behavior, a risk of regional and distant metastasis, and limited systemic treatment options in advanced disease. Vandetanib is one of the therapeutic options for progressive unresectable locally advanced and metastatic medullary thyroid carcinoma; however, published evidence on its use in real-world clinical practice in Kazakhstan remains limited. Objective: To describe the use of vandetanib in a patient with metastatic medullary thyroid carcinoma in real-world clinical practice in Kazakhstan and to analyze the long-term disease course, treatment monitoring, and multidisciplinary management. Materials and methods: A retrospective analysis of a clinical case of a patient with medullary thyroid carcinoma was performed based on medical history, hospital discharge summaries, surgical treatment records, laboratory findings, computed tomography data, and clinical documentation collected over more than six years of follow-up. Tumor progression, distant metastatic spread, functional status, comorbidities, and features of monitoring during vandetanib therapy were assessed. Results: The patient was diagnosed with medullary thyroid carcinoma and underwent surgical treatment. During long-term follow-up, disease progression with metastatic spread involving the lungs, intrathoracic structures, and bone tissue was documented. At the stage of disseminated disease, targeted therapy with vandetanib was initiated. Patient management required regular laboratory, imaging, and cardiac monitoring because of significant comorbidity, the risk of adverse events, and the need for safety surveillance during treatment. Conclusion: This clinical case demonstrates the feasibility of using vandetanib in a patient with metastatic medullary thyroid carcinoma in real-world clinical practice in Kazakhstan. Treatment with vandetanib requires a personalized approach, careful patient selection, multidisciplinary support, and regular safety monitoring, particularly in patients with cardiovascular and metabolic comorbidities. Reporting such cases is important for expanding national experience with targeted therapy in rare thyroid malignancies.