Mutations of codon 918 in the RET proto-oncogene correlate to poor prognosis in sporadic medullary thyroid carcinomas.
The hereditary multiple endocrine neoplasia syndromes types 2A and B (MEN 2A and B) were recently linked to germline mutations in the RET proto-oncogene, altering one of five cysteine residues in exon 10 or 11 (MEN 2A), or substituting a methionine for a threonine at codon 918 in exon 16 (MEN 2B). The latter mutation also occurs somatically in some sporadic medullary thyroid carcinomas (MTC), and has in a previous study been correlated with a less favorable clinical outcome. In the present study, 46 MTCs were selected for investigation of the codon 918 mutation. The mutation was found in 29 tumors (63%), and was significantly correlated with a poor outcome, with regard to distant metastasis or tumor recurrence (p < 10(-4)). Two tumors showed multifocal growth and C-cell hyperplasia, and these patients were therefore also investigated for germline mutations in exons 10, 11 and 16. The codon 918 mutation was found only in the tumors, thus of somatic origin. The RET codon 918 mutation may have prognostic impact, and therefore preoperative assessment may influence decision-making in the treatment of patients suffering from MTC.
Zedenius
J
J
Department of Surgery, Karolinska Hospital, Stockholm, Sweden.
Larsson
C
C
Bergholm
U
U
Bovée
J
J
Svensson
A
A
Hallengren
B
B
Grimelius
L
L
Bäckdahl
M
M
Weber
G
G
Wallin
G
G
D001483:Base Sequence; D018276:Carcinoma, Medullary / Q000235:genetics* / Q000401:mortality; D003062:Codon; D017931:DNA Primers; D029721:Drosophila Proteins; D006801:Humans; D008715:Methionine; D008969:Molecular Sequence Data; D009377:Multiple Endocrine Neoplasia / Q000235:genetics; D018813:Multiple Endocrine Neoplasia Type 2a / Q000235:genetics; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011379:Prognosis; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D051096:Proto-Oncogene Proteins c-ret; D011519:Proto-Oncogenes; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D013912:Threonine; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000401:mortality
D003062:Codon; D017931:DNA Primers; D029721:Drosophila Proteins; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D013912:Threonine; D008715:Methionine; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila