Spectrum of KIT/PDGFRA/BRAF mutations and Phosphatidylinositol-3-Kinase pathway gene alterations in gastrointestinal stromal tumors (GIST)

Pathogenetic pathways of gastrointestinal stromal tumors (GIST) lacking mutations in KIT and PDGFRA (similar to 15%) are still poorly studied. Nearly nothing is known about PI3K alterations in GISTs and only a few GISTs with BRAF mutations have been reported. BRAF mutations (V600E) were found in 3/87 tumors (3.5%) concomitantly were wild type for KIT and PDGFRA. No mutations were detected in KRA.S, NRAS, and FGFR3. For the first-time we demonstrated a PIK3CA mutation (H1047L) simultaneously occurring with a 15-bp deletion in KIT exon 11 in one tumor. We suggest that BRAF mutations are of pathogenetic significance in wild type GISTs. The PI3K pathway should be assessed in future studies. (C) 2011 Elsevier Ireland Ltd. All rights reserved