Abstract
Medullary thyroid cancer (MTC) accounts for ~10% of thyroid carcinomas and occurs in sporadic and hereditary forms. Early diagnosis significantly impacts the clinical course, management and outcome of the disease. The identification of germline-activating mutations of the rearranged during transfection oncogene in patients with hereditary MTC led to significant progress in the diagnostic and therapeutic approach, thus improving the quality of care provided, and consequently, disease prognosis. In the present review, various aspects of genetic screening (GS) in MTC will be covered, which elucidate the value of GS in guiding clinical decision making, therapy selection and appropriate genetic counseling of the affected families. GS should be offered to every MTC patient, based on the personal and family medical history, to allow optimal clinical management and follow-up.
Financial & competing interests disclosure
The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
No writing assistance was utilized in the production of this manuscript.
Hereditary medullary thyroid cancer (MTC) is a component of multiple endocrine neoplasia (MEN) 2 syndromes, caused by germline gain-of-function mutations of the rearranged during transfection gene.
Genetic testing facilitates early diagnosis of MEN2 with a marked impact on the patients’ outcome. Furthermore, asymptomatic gene carriers within the family receive valuable genetic advice and preemptive guidance as per the need and appropriate timing of prophylactic thyroidectomy.
Routine genetic testing should be performed to every MTC patient; it can lead to the identification of a mutation in an apparently sporadic MTC case, thus reclassifying it as hereditary with obvious clinical implications.
Given the genotype–phenotype correlation characterizing MEN2 syndromes, the European Thyroid Association advocates a codon-oriented approach when performing genetic analysis; in the presence of a negative result and when the family history and clinical presentation raise suspicion of hereditary disease, DNA testing should be extended to cover all the remaining exons of the rearranged during transfection gene.