RecruitingClinical trialPatient Decision Aid in Supporting Decision-Making About When to Start or Stop New Drugs, Join Clinical Trials, or Continue Active Surveillance in Patients With Medullary Thyroid Cancer and Their CaregiversThis trial develops and studies how well a patient decision aid works in supporting decision-making about when to start or stop new drugs, join clinical trials, or continue active cancer monitoring for patients with medullary thyroid cancer and their caregivers. Developing a patient decision aid may help patients with medullary thyroid cancer make well-informed decisions about their cancer care and be able to discuss their preferences with their doctors.