RT Book, Section A1 Hong, Nicole J. Look A1 Raut, Chandrajit P. A2 Zinner, Michael J. A2 Ashley, Stanley W. A2 Hines, O. Joe SR Print(0) ID 1160040797 T1 Gastrointestinal Stromal Tumors T2 Maingot's Abdominal Operations, 13e YR 2019 FD 2019 PB McGraw-Hill Education PP New York, NY SN 9780071843072 LK accesssurgery.mhmedical.com/content.aspx?aid=1160040797 RD 2024/03/29 AB Gastrointestinal stromal tumors (GISTs) are rare neoplasms. Although they represent only 0.1% to 3% of all gastrointestinal malignancies,1–4 they account for 80% of gastrointestinal mesenchymal neoplasms.5 Approximately 5000 to 6000 new cases are diagnosed per year in the United States, for an annual incidence of 14.5 per million and prevalence of 129 per million.6 In the last 15 years, the understanding and treatment of GIST has witnessed remarkable advances due to two key developments: (1) the identification of constitutively active signals (oncogenic mutation of the c-KIT and platelet-derived growth factor alpha [PDGFRA] gene-encoding receptor tyrosine kinases) and (2) the development of therapeutic agents that suppress tumor growth by specifically targeting and inhibiting these signals. These developments in the management of GIST illustrate the principle of translational therapeutics in oncology, confirming that specific inhibition of tumor-associated receptor tyrosine kinase activity is an effective cancer treatment. The advent of effective targeted medical therapy for GIST has increased the complexity of management and opened new dialogues regarding the need for integrated multimodality therapy. This chapter reviews the biology, treatment, and emerging clinical challenges of these mesenchymal neoplasms.