Molecular features of thyroid cancer in children

Abstract

Background. Malignant neoplasms of the thyroid gland are the most common endocrine malignant neoplasms in the children’s age group. Unlike adults, who most often have BRAF and RAS mutations, children have chromosomal displacements. The relevance is explained by the lack of comprehensive studies on thyroid cancer in children in the Russian-language literature.The aim of the study is — to summarize and systematize the literature data on the molecular features of thyroid cancer in children.Materials and methods. The authors conducted a search for publications in the PubMed electronic database using the following algorithm: Molecular AND Thyroid cancer AND pediatrics. We found 451 publications, and after reviewing the annotations, 111 studies describing the molecular features of thyroid cancer in the pediatric population were included in the review. Publications were excluded due to duplication and inconsistency with the subject of this study.Results. Instead of point mutations of BRAF and RAS, characteristic of adults, regardless of radiation status, chromosomal displacements are more common in children. Re-arrangement of RET/PTC genes is the most common, followed by BRAF fusions. Mutations of the TERT promoter, which are markers of the aggressive course of the disease in adults, are rare in children. DICER1 mutations appear to play a key role in pediatric cases of follicular and papillary thyroid cancer. Medullary thyroid cancer (MTC) in children requires the exclusion of multiple endocrine neoplasia syndrome (MEN type 2). Tumors originating from follicular cells other than MTC can rarely be familial. Literature data on the role of microRNA as a biomarker in thyroid carcinomas in children is currently limited.