Molecular analysis of c-Kit and PDGFRA in GISTs diagnosed by EUS

• Autor(a) principal: Gomes, Ana L.
• Data de Publicação: 2007
• Outros Autores: Bardales, Ricardo H., Milanezi, Maria Fernanda Grillo, Reis, R. M., Schmitt, Fernando
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/48383
• topic: Endoscopic ultrasound-guided fine-needle aspiration; c-Kit; Platelet-derived growth factor-α; PDGFRA; Gastrointestinal stromal tumor; GIST; Mutations; Science & Technology

Gastrointestinal stromal tumors (GISTs) are characterized by overexpression and mutations of c-Kit. Approximately 80% of c-Kit mutations occur in exon H, being a response factor to imatinib (Gleevec) therapy. Mutations of platelet-derived growth factor receptor-a (PDGFRA) are observed in a subset of GISTs lacking c-Kit mutations. We aimed to assess whether c-Kit and PDGFRA mutation analysis of GISTs obtained by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) could be routinely performed. Mutation analysis of c-Kit hotspot exons (9, 11, 13, and 17) and PDGFRA hotspot exons (12 and 18) was performed in aspirates of 33 GISTs and 18 non-GIST mesenchymal tumors. Of the GIST cases, 19 (58%) of 33 contained a mutation in exon 11, 1 (3%) in exon 9, and none in exons 13 and 17. No activating c-Kit mutations were identified in non-GIST cases. No PDGFRA mutation was detected. Mutation analysis is possible in these FNA cell blocks and can assist in the diagnosis and therapeutic decisions in GIST cases.