A Case of Anaplastic Thyroid Carcinoma in a 90-year-old Patient Successfully Treated with a Combination of Dabrafenib and Trametinib

Abstract

A 90-year-old woman presented with a tumor in the left lobe of the thyroid gland and an enlarged cervical lymph node. The patient experienced significant pain associated with the tumor. Computed tomography (CT) revealed a solid thyroid mass with tracheal invasion and enlarged cervical lymph nodes suggestive of thyroid carcinoma with lymph node metastasis. Distant metastases were not observed. The core needle biopsy confirmed anaplastic thyroid carcinoma (ATC). Genetic analysis revealed a BRAF V600E mutation. Given the unresectability of ATC, targeted therapy with dabrafenib and trametinib was initiated. Within one week, the tumor exhibited rapid regression, and tumor-associated pain significantly diminished. After two months of treatment, the follow-up CT demonstrated a marked reduction in both the primary tumor and metastatic lymph nodes. During treatment, the patient experienced grade 1 fever, which was managed with oral acetaminophen. No adverse events requiring dose reduction or discontinuation occurred. Combination therapy with dabrafenib and trametinib was useful in achieving local control of ATC and improving the patient's quality of life.