Gastric and small intestine gastrointestinal stromal tumors: Do outcomes differ?

Background and Objectives: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Previous literature has suggested that small intestine GISTs are more aggressive than gastric GISTs. Our primary objective was to compare the outcomes of gastric and small intestine GISTs in the decade after approval of imatinib for treatment. Methods: The SEER database was queried for cases of gastric and small intestine GIST between the years 2002 and 2012, using the ICD-O-3 histology code 8936. Survival analysis was performed using generalized gamma models for time to cause-specific mortality (CSM). Results: CSM was 14.0% for the 3,759 gastric GIST patients and 14.3% for the 1,848 small intestine GIST patients. Five-year survival was 82.2% and 83.3% for gastric and small intestine patients, respectively. The number of diagnosed cases of GIST increased over the course of this study, especially for tumors <5cm in size and in patients over age 50years. Conclusions: In this large nation-wide study, we found that patients with gastric and small intestine GISTs had similar outcomes, in contrast to previous reports. The diagnosis of GIST has significantly increased in the last decade, which may reflect the increased recognition of this entity and frequent use of imaging. J. Surg. Oncol.