Cardiac Metastasis from Medullary Thyroid Cancers with Long-Term Survival under Vandetanib.

Background: Cardiac metastases from thyroid cancers are uncommon with a poor prognosis. There is a lack of long-term follow-up studies.

Cases: We report 2 cases of cardiac metastasis from medullary thyroid cancer (MTC). Both patients presented limited metastatic disease apart from a cardiac metastasis. The initial diagnosis was challenging and was facilitated by functional imaging with an immuno-PET-CT using an anti-CEA bispecific antibody and a ⁶⁸Ga-labeled peptide. Both patients were treated with the multitarget kinase inhibitor vandetanib with prolonged stability. The first patient was alive at the last follow-up, 14 years after the diagnosis of cardiac metastasis. The second patient required surgical excision of the cardiac mass because of disease progression under vandetanib.

Conclusion: These cases illustrate long-term survival and effectiveness of clinical management of 2 patients who developed cardiac metastases from MTC, in the current era of personalized medicine with targeted therapy.