Advanced gastrointestinal stromal tumors: 10-years experience from a tertiary care centre

Background: Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract. We aimed to study the pattern of presentation and treatment outcome of advanced GIST patients seen by us in a 10- year period. Methods: Medical records of GIST patients seen between years 2002-2012 were retrieved from institute as well as database maintained by authors. Patient included in this analysis had metastatic disease and unresectable and/or residual disease after surgery. Results: During the study period 62 patients fulfilled the inclusion criteria but 6 were lost to follow up before treatment and hence 56 patients were analysed. Median age was 45.5 years (range 17-70 years) with a male female ratio of 2:1. Thirty eight (67%) patients had metastatic disease whereas 32% patients had unresectable or incompletely resected disease. The most common primary site was small intestine in 24 (42.8%) which was followed by stomach in 11 (19.6%) patients. The most common site of metastases was liver in 27 (48%) patients. Median tumor size was 12 cm (range 4-50 cm). Thirty two (57%) patients had mitotic counts of >5/50 HPF. All patients received imatinib. The most common response seen with imatinib was stable disease achieved in 29 (52%) patients. Imatinib was well tolerated by all patients without any drug discontinuation. The 5-year EFS and OS were 35% and 49%, respectively at a median follow up of 55 months. None of the patient or tumor factors were found to have prognostic significance in univariate survival analysis. Conclusions: This is a single center experience of advanced GIST patients where small intestine was found to be the commonest disease site with imatinib producing disease stabilization in more than half of patients. Even though the survival was comparable to published reports, the major limitation was lack of mutation analysis