Oncogenic alterations in papillary thyroid cancers of young patients.

Background: Papillary thyroid carcinoma (PTC) in young people usually has an aggressive initial presentation, though a good general prognosis despite recurrences in 10%–20% of patients. A number of genetic alterations that activate the mitogen-activated protein kinase (MAPK) pathway have been found in PTC. Some of these alterations have been identified as prognostic factors of PTC in adults. The objective of the current study was to comprehensively characterize all known oncogenic alterations of the MAPK pathway in young people. Methods: One hundred three PTCs removed from 9 children, 19 adolescents, and 75 young adults were submitted to molecular analyses. Results: Altogether, 57 alterations were found in 56 PTCs (55%) corresponding to V600E BRAF in 20.3%, RAS mutations in 12.6%, RET/PTC 1 in 11.6%, RET/PTC 3 in 8.7%, and rearrangement of NTRK in 1.9%. The prevalence of all alterations increased with age (22.2% in children; 52.6% in adolescents, 51.4% in adults 20–25 years, and 55.1% in adults 25–35 year...