| [ Summary ] |
Because of improved ability to observe expression of KIT, gain-of-function mutation of c-kit or PDGFRA gene, and significant improvements in molecular targeted drug efficacy for GISTs has been reported. Therefore, diagnosis and therapy for GISTs has dramatically changed over the past decade. Pathological diagnosis of GISTs is not difficult if the location of the primary site, characteristic histology, and immunohistochemical results are appropriately examined. However, there are rare GIST subtypes which exhibit weak or negative KIT staining with or without c-kit or PDGFRA gene mutation. Subclassification of these GISTs seems to be needed for appropriate drug administration, prediction of drug efficacy, and identifying new targets for molecular targeted drugs for tumors. |