A Patient with an Advanced Medullary Thyroid Cancer and Progressive, Symptomatic Distant Metastases: When to Start Systemic Therapy

Abstract

We present the case of a male patient who presented with what appeared to be sporadic medullary thyroid cancer (MTC) but, with RET genetic screening that revealed a germline Ser891Ala mutation, was actually a familial case. He was initially treated with surgery that was ineffective in obtaining cure of disease, as one could expect since several lymph node metastases were already present at the time of diagnosis. After 2 years of good health and stable disease, because of the development of a severe diarrhea, the patient was enrolled in a clinical phase II trial with motesanib, the first tyrosine kinase inhibitor tested in MTC patients. Unfortunately, after a few months, the drug had to be discontinued because of the development of drug-related side effects. After a 7-year period of stabilization of the disease, a rapid growth of lung and lymph node lesions was observed and the patient was treated with vandetanib. After a few weeks of therapy, he developed severe erythroderma related to sunlight exposure. The drug was stopped followed, 2 weeks later, by complete resolution of the skin lesions. The drug was restarted at a lower dose, and a balance between tumor growth control and the side effects was attained. The patient is still receiving vandetanib and his quality of life remains good.