Systemic targeted therapy for metastatic or advanced medullary thyroid cancer

aaMKI: anti-angiogenic multitargeted kinase inhibitor; ECOG PS: Eastern Cooperative Oncology Group performance status.

* Follow calcitonin and carcinoembryonic antigen levels every 3 to 6 months. Imaging of metastatic sites at intervals based on clinical factors (eg, calcitonin doubling time, location of lesions, overall burden of disease).

¶ Clinical trial options are often dictated by the presence of specific gene mutations or signaling pathway abnormalities that are the targets of approved or investigational therapies.

Δ Contraindications to aaMKIs may include:

• Major surgery within 28 days
• Active bleeding
• Untreated hemorrhagic brain metastases
• Encasement by tumor of major arteries such as the carotid
• Arterial thromboembolic event within the last 6 to 12 months

We also try to minimize use of potent aaMKIs in patients with prior external beam radiotherapy to the neck due to reports of tracheoesophageal fistulas.

◊ Biopsy of the growing resistant tumor to identify the mechanism of resistance or to identify the emergence of a targetable mutation may be useful for determining eligibility for a clinical trial or a different therapy.