title: Low frequency of BRAFT1796A mutations in childhood thyroid carcinomas.
abstract: A high prevalence of the activating BRAF mutation, BRAF(T1796A), is observed in adult papillary thyroid carcinomas (PTCs). The prognosis of childhood PTCs is generally fairly good despite the fact that distant metastases are often documented in these cases. To investigate the differences between the characteristics of childhood and adult PTCs, we analyzed both BRAF(T1796A) and RAS mutations in 31 Japanese and 48 post-Chernobyl Ukrainian thyroid carcinomas. In the 31 Japanese childhood cases, BRAF(T1796A) was found in only one instance (3.2%), and no RAS mutations were detected. In the Ukrainian subjects, of the 15 childhood and the 33 adolescent and young adult PTCs examined, the BRAF(T1796A) mutation was found in zero and eight cases, respectively, and RAS mutations were found in two of the young adult cases. In addition, 17 of the 48 Ukrainian cases showed expression of the RET tyrosine kinase region, indicating the existence of RET/PTC rearrangements. Unlike adult PTCs, we could detect no positive association between BRAF(T1796A) mutations and clinical parameters in the childhood carcinomas, suggesting that a low prevalence of BRAF(T1796A) is a common feature of PTCs in children regardless of radiation exposure levels. The differences in the prevalence of BRAF(T1796A) mutations between childhood and adult cases of PTC may well reflect inherent differences in the clinical features of these cancers between the two age groups.
authors.affiliation: Department of Molecular Medicine, Atomic Bomb Disease Institute, Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kumagai
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Namba
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Saenko
authors.forename: Kiyoto
authors.initials: K
authors.lastname: Ashizawa
authors.forename: Akira
authors.initials: A
authors.lastname: Ohtsuru
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ito
authors.forename: Naofumi
authors.initials: N
authors.lastname: Ishikawa
authors.forename: Kiminori
authors.initials: K
authors.lastname: Sugino
authors.forename: Koichi
authors.initials: K
authors.lastname: Ito
authors.forename: Stephen
authors.initials: S
authors.lastname: Jeremiah
authors.forename: Geraldine A
authors.initials: GA
authors.lastname: Thomas
authors.forename: Tatyana I
authors.initials: TI
authors.lastname: Bogdanova
authors.forename: Mykola D
authors.initials: MD
authors.lastname: Tronko
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nagayasu
authors.forename: Yoshisada
authors.initials: Y
authors.lastname: Shibata
authors.forename: Shunichi
authors.initials: S
authors.lastname: Yamashita
mesh_terms: D000293:Adolescent; D002291:Carcinoma, Papillary / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D007223:Infant; D008297:Male; D009154:Mutation; D015513:Oncogene Proteins / Q000235:genetics; D011210:Power Plants; D048493:Proto-Oncogene Proteins B-raf; D019908:Proto-Oncogene Proteins c-raf / Q000235:genetics*; D051096:Proto-Oncogene Proteins c-ret; D018788:Radioactive Hazard Release; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D013964:Thyroid Neoplasms / Q000235:genetics*; D014455:Ukraine
chemical_list: D015513:Oncogene Proteins; D051096:Proto-Oncogene Proteins c-ret; C099282:RET protein, human; D020794:Receptor Protein-Tyrosine Kinases; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D019908:Proto-Oncogene Proteins c-raf