Current management and prognostic features for gastrointestinal stromal tumor (GIST)

Stromal or mesenchymal neoplasms affecting the GI tract have undergone a remarkable evolution in how they are perceived, classified, approached, diagnosed and managed over the last 30？years. A major breakthrough occurred with the discovery of expression of the CD117 antigen by almost all gastrointestinal stromal tumors (GIST)[1]. The other group of spindle cell neoplasms arising in the GI tract includes lipomas, schwannomas, hemangiomas, usual leiomyomas and leiomyosarcomas are typically CD117-negative [2]. The CD117 molecule is part of the KIT (c-kit) receptor tyrosine kinase that is a product of the KIT proto-oncogene (Figure？1). GIST research and clinical care sets another great example of translational research that turns laboratory discovery to successful clinical application. From this fundamental mechanistic understanding of GIST, a series of worldwide investigations and trials have developed novel and effective ways to approach patients with this disease. In this review, we discuss the basics of GIST and highlight recent advances and their relevance to current clinical practice as well as future directions.GISTs account for approximately 1% to 3% of all malignant GI tumors [3]. Epidemiologic data such as that from Surveillance, Epidemiology and End Results (SEER) program are difficult to interpret since the earlier definition of "malignant GIST" was derived from criteria published in 1990, before GIST was molecularly characterized [4]. The estimated incidence of GIST has been revised upward to approximately 5,000 new cases per year in the United States (US) [5,6]. The most dependable international epidemiologic data are from population-based studies that reexamined all cases of potential GIST [7-10]. These studies reported annual incidence of GIST ranging from 11 to 14.5 per million population. More recent studies suggest that the incidentally detected sub-centimeter gastric GIST lesions may be more frequent than expected [11,12].The clinical features can va