Ianis Boukovinas, Jean-Yves Blay, Axel Le Cesne, Joan Mac Clure, Robert G. Maki, Maria Debiec-Richter, Pancras C.W. Hogendoorn, Frits van Coevorden, Ian Judson, Rafael Ramos, George D. Demetri, Ninna Nupponen, Piotr Rutkowski, Karen H. Antman, Jaap Verweij, Heikki Joensuu, Peter Reichardt, Pierre Meeus, Larry Baker, Ronald P. DeMatteo, Thor Alvegård, Isabelle Ray-Coquard, Louis Guillou, John Zalcberg, Dolores Knufer, Ole S. Nielsen, Seiichi Hirota, Mike Leahy, Peter Hohenberger, Andres Poveda, Raf Sciot, Robert S. Benjamin, Joan Maurel, Rosella Bertulli, Alessandro Gronchi, Jean-François Emile, Jean Michel Coindre, Allan T. van Oosterom, Maurizio Colecchia, Michael Heinrich, Bert Van Geel, Javier Martin, Martine Van Glabbeke, A. P. Dei Tos, Paolo G. Casali, Sigrid Stroobants, Toshirou Nishida, Kirsten Sundby-Hall, Jim Janinis, Margaret von Mehren, Haesun Choi, Christopher L. Corless, Antonella Messina, Serge Leyvraz, Elena Tamborini, Binh Bui, Sylvie Bonvalot, Béatrice Fervers, and Aage Schultz
The management of gastrointestinal stromal tumors (GIST) has evolved very rapidly in the last 4 years. The objectives of this international consensus meeting were to describe the optimal management procedures for patients with GIST in localized and advanced stages, as well as research issues for the future.A panel of experts from six specialties, including pathology, molecular biology, imaging, surgery, medical oncology and methodologists for clinical practice guidelines from different European and extra European sarcoma societies were invited to a 2-day workshop. Several questions were selected by the organizing committee prior to the conference. Selected panelists reviewed the current levels of evidence for each point, and presented their conclusions during the meeting. These proposals were discussed, and consensus points were identified and categorized according to the Standard Options Recommandations (SOR) of the French Federation of Cancer Centers and National Comprehensive Cancer Network (NCCN).Thirty-two consensus points were identified, most from categories 2A of the NCCN and B2 of the SOR. Among these, the standard histological examination with immunohistochemical analysis using CD117, CD34, PS100, desmin and smooth muscle actin is considered standard. Molecular biology for the identification of KIT and PDGFRA mutation is an optional diagnostic procedure for GIST with negative CD117 staining, and otherwise is considered a research procedure. Complete tumor resection with negative tumor margins is the standard surgical treatment. Adjuvant imatinib after optimal tumor resection as well as neo-adjuvant imatinib remain experimental approaches to be performed within prospective clinical studies. Imatinib should be started at the date of diagnosis of metastatic relapse and given until development of intolerance or progressive disease. The optimal criteria for tumor response to imatinib remain to be delineated, and should include not only tumor size reduction or disease stabilization, but also reduction of tumor density (Hounsfield Units) on computed tomography and metabolic activity (i.e. reduction of FDG uptake on positron emission tomography). In a substantial proportion of patients, stable disease and even increase in tumor size may be associated with pathologic response to imatinib therapy, and available survival data indicate that the survival of these patients is similar to that of patients with conventional tumor response. Metastasis resection is an experimental procedure.Consensus points in clinical management of GIST as well as questions for future clinical trials were identified during this consensus conference on GIST management.