Management of Advanced Medullary Thyroid Carcinoma with Vandetanib: Case Series

Objective: To describe the tumor response and adverse events in patients with advanced medullary thyroid carcinoma (MTC) treated with vandetanib at the National Cancer Institute in Bogotá, Colombia. Materials and Methods: Case series including five patients with advanced MTC treated with vandetanib from April 2011 to August 2018 and a minimum follow-up of 6 months. Results: 5 patients met the inclusion criteria, including 3 women. The mean age was 49 years. A total of 4 patients underwent total thyroidectomy prior to starting vandetanib. The main indication for vandetanib was progression of liver metastasis (4 patients). Regarding treatment response, 3 patients presented stable disease, 1 patient showed partial response, and 1 had disease progression. The mean treatment duration was 16.5 months. Grade 3 or 4 adverse events were observed in three patients, 1 with diarrhea, 1 with hypertension, and 1 with rash. All symptoms improved with dose reduction or temporary suspension of vandetanib. Conclusions: The management of advanced MTC with vandetanib allows for prolonged disease control (stable disease or partial response). Although adverse events are frequent, most are mild and severe cases are manageable.