Comparing the long-term outcomes among patients with stomach and small intestine gastrointestinal stromal tumors: An analysis of the National Cancer Database

Background and Objectives: Gastrointestinal stromal tumors (GIST) are the most common sarcoma arising from the gastrointestinal tract. Data regrading long-term prognosis based on tumor location (stomach vs small intestine) are mixed, so we aimed to analyze their outcomes using a large national oncology database. Methods: The National Cancer Database was queried for cases of stomach and small intestine GIST between the years 2004 and 2014. Survival analysis was performed using the Kaplan-Meier method, and factors related to survival were compared using the Cox proportional hazards model. Results: Of 18 900 total patients, those with small intestine GIST had larger median tumor size (6.2 cm; interquartile range [IQR], 3.8 to 10.0 vs stomach: 5.0 cm; IQR, 3.0 to 9.0; P < 0.001) and a higher incidence of tumors with ≥5 mitoses/50 HPF (29.3% vs stomach: 24.2%; P < 0.001). Unadjusted median overall survival (OS) was longer for patients with stomach GIST (10.3 years) as compared to small intestine GIST (9.4 years) (P = 0.01). After controlling for patient and tumor-related factors, however, OS did not differ between stomach and small intestine GIST (hazard ratio, 1.19; 95% confidence interval, 0.88 to 1.61; P = 0.26). Conclusions: Patients with small intestine GIST more commonly have larger, high mitotic rate tumors, but despite these worse prognostic features, tumor location did not independently impact OS.