Review: Chemoembolization for liver metastases from medullary thyroid carcinoma

Background: Medullary thyroid carcinoma (MTC) is a well-differentiated neuroendocrine tumor. Distant metastases are the main cause of cancer-related death. Systemic chemotherapy produces only rare tumor responses. Somatostatin analogs and other available modalities are poorly effective to control symptoms. Aims: The aim of our study was to evaluate the impact of liver transarterial chemoembolization (TACE) in MTC patients with predominant and progressive liver metastases. Patients and Methods: Twelve MTC patients underwent 18 TACE courses (mean, 1.5; range, 1-2). Response evaluation criteria in solid tumors were used to evaluate tumor responses. Symptomatic responses were defined by more than a 25% decrease of symptoms intensity. Results: Partial radiological tumor response was obtained in five patients (42%) with a median duration of 17 months (mean, 19; range, 15-28 months), stabilization in five (42%) with a median duration of 24 months (mean, 24; range, 4-39 months), and progression in the remaining two (16%). The five partial tumor responses were observed in the nine patients with less than 30% liver involvement. Clinical response was observed in two of the five patients with diarrhea. Carcinoembryonic antigen did not appear to be a useful marker in this setting. Significant grade 3-4 toxicity was observed in one patient who had a major tumor necrosis after TACE. Conclusion: TACE should be considered for treating MTC patients with progressive and predominant liver metastasis, and preferably at an early stage during the course of metastatic disease.