708P - Real-Life Management of advanced Gastrointestinal Stromal Tumors (GIST) Treated with Imatinib in France

Abstract

ABSTRACT Introduction GISTs are rare tumors of the gastrointestinal tract. Imatinib has been approved for the treatment of Kit+ unresectable or metastatic GIST since 2002. However, information is lacking in the real-life, non-trial setting on the efficacy, use, and safety of imatinib, and the quality of life of imatinib-treated patients. The EPIGIST study was set up in 2006 in France to obtain this information. Method EPIGIST is a multicenter, observational, longitudinal follow-up cohort study conducted in France on patients diagnosed with a Kit + unresectable or metastatic GIST, treated with imatinib for the first time, between its market introduction and 2011. Sites were selected at random from a national file of oncologists, gastroenterology surgeons, and gastroenterologists. The intended follow-up period was 3 years. A clinical case report form was completed at enrollment and at each visit. Results 31 sites enrolled at least one patient. A total of 164 patients were enrolled, 151 were analyzed. Median age at diagnosis was 60 years (range: 21–86 years), sex ratio was predominantly male (58%). The commonest locations of the primary GIST at diagnosis were stomach (46%) and small intestine (37%). 85 (56%) analyzed patients had localized disease at diagnosis, and 42 (49%) were at high risk of relapse according to Miettinen's classification; 60 (70%) had developed metastatic disease by the time imatinib therapy was instituted (median 13 months after diagnosis; range 0–135 months). The starting dose of imatinib for 148 (98%) patients was 400 mg/day. The estimated 4-year overall survival was 60.7% (95% CI: [51.4%; 68.8%]), with a median follow-up of 4 years. Adverse events disorders were gastrointestinal (70%), general disorders and administration site conditions (70%), eye (38%), musculoskeletal and connective tissue (35%), and skin and subcutaneous tissue (34%). Conclusion The EPIGIST observational study confirms that the results of the clinical studies are maintained in the real-life setting. The indications for imatinib have been recently extended to include the adjuvant treatment of patients at significant risk of relapse following resection of Kit+ GIST. This population is not described in this study. Disclosure O. Bouche: Consulting fees from Novartis and Pfizer. A. Le Cesne: Honorary Grants from Novartis, Pfizer, Pharmamar. P. Xavier: Employment full time Novartis. J. Blay: Research grants: Novartis, Roche, GSK, Pfizer, Pharmamar Consulting fees: Novartis, Roche, GSK, Pfizer, Pharmamar. All other authors have declared no conflicts of interest.