Molecular advances in medullary thyroid cancer diagnostics

Germline activating mutations in the RET proto-oncogene cause inherited medullary thyroid cancer (MTC) and the multiple endocrine neoplasia type 2 (MEN2) syndrome. Identification of a RET mutation in an individual with MEN2 allows pre-symptomatic genetic testing of other at-risk family members, and guides early intervention to prevent death and serious morbidity from MTC. Developments in the understanding of downstream RET receptor signalling pathways and how activating mutations disturb receptor function has led to insights into the possible molecular mechanisms underlying the different MEN2 phenotypes. Mutation analysis of RET in individuals with MEN2 has identified a number of different mutations, and correlation with cancer biology and clinical outcome has led to tailoring of management according to the mutation detected.