Inherited cancer syndromes and the thyroid: An update

PURPOSE OF REVIEW: Knowledge related to hereditary thyroid cancer syndromes has expanded enormously. This review identifies contributions that have changed approaches to diagnosis and broadened treatment options for patients with hereditary medullary and nonmedullary thyroid cancers related to multiple endocrine neoplasia type 2 (MEN2), Cowden syndrome, and familial adenomatous polyposis (FAP). RECENT FINDINGS: A new risk-stratification scheme based on type of RET gene mutation informs the age at which prophylactic thyroidectomy and diagnostic screening for MEN-associated endocrine diseases should occur. Two new US Food and Drug Administration-approved targeted medical therapies are now available for medullary thyroid cancer. There is better understanding of more aggressive clinical features and increased lifetime cancer risks for patients with well differentiated thyroid cancers as part of families with and without Cowden syndrome or FAP. This has led to a clearer appreciation for the role and timing of thyroid ultrasound screening in these populations. It has also informed the appropriate extent of thyroid surgery and the circumstances in which prophylactic thyroidectomy is reasonable to consider as part of hereditary syndromes other than MEN2. SUMMARY: Recognition and early diagnosis of these syndromes allows for comprehensive medical care and may improve thyroid cancer-related outcomes. Ultrasound-based screening programs to detect thyroid disease are advised for patients and family members with hereditary cancer syndromes.