Evidence of a low prevalence of RAS mutations in a large medullary thyroid cancer series.
Thyroid
; 23(1): 50-7, 2013 Jan.
Article
em En
| MEDLINE
| ID: mdl-23240926
ABSTRACT
BACKGROUND:
Approximately 60% of sporadic medullary thyroid carcinomas (sMTC) remain orphan of a recognized genetic cause. Recently, a high percentage of RAS point mutations have been described in RET-negative sMTC. The aim of this study was to assess the prevalence of RAS point mutations in a large series of MTC collected in four Italian centers.METHODS:
For this purpose, we studied codons 12, 13, and 61 of H-, K-, and N-RAS genes in 188 MTC samples, either hereditary or sporadic, by direct sequencing. Correlations between the RAS mutational status and the clinical-pathological features of MTC patients as well as a meta-analysis of all published data were performed.RESULTS:
The prevalence of RAS mutations in the present series of MTC was 10.1%, and 17.6% when considering only RET-negative cases. RAS mutations were found in MTC tumoral tissue, but not in peripheral blood indicating their somatic origin. A novel mutation in codon 72 (M72I) was found, but with a low or null transforming potential. No association was found between the presence of RAS mutations and the clinical-pathological features of the patients. Although not statistically significant, a positive association between the presence of RAS mutations and a better outcome was observed. The meta-analysis of all published studies confirmed a prevalence of 8.8% for RAS mutations in MTC.CONCLUSIONS:
The prevalence of RAS mutations in our MTC series was relatively low and consistent with the meta-analysis data. Only somatic RAS mutations were found and only in RET-negative sMTC. Likewise, MTCs that harbor a RAS mutation identify a subgroup of tumors with less aggressive behavior. To our knowledge, this is the largest series of MTCs studied for the presence of mutations in RAS genes and the first meta-analysis on this specific topic.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Glândula Tireoide
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Genes ras
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Mutação Puntual
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Carcinoma Medular
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Neoplasia Endócrina Múltipla Tipo 2a
Tipo de estudo:
Prevalence_studies
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Risk_factors_studies
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Systematic_reviews
Limite:
Adult
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Aged
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Aged80
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Female
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Humans
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Male
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Middle aged
País/Região como assunto:
Europa
Idioma:
En
Revista:
Thyroid
Ano de publicação:
2013
Tipo de documento:
Article