Gastrointestinal stromal tumors of the esophagus: evaluation of a pooled case series regarding clinicopathological features and clinical outcome

Background and Objectives: To elucidate diagnostic criteria, clinicopathological features and clinical outcome in patients with esophageal gastrointestinal stromal tumors (GIST), representing an extremely rare subform of GIST with an estimated incidence of about 0.1 to 0.3 per million people. Patients and methods: Esophageal GIST cases from the Ulmer GIST registry consisting of 1077 cases were pooled with case reports and case series of esophageal GIST extracted from MEDLINE. Data were compared with those from 683 cases with gastric GIST from the Ulmer GIST registry. Results: In comparison to gastric GIST, esophageal GIST (n = 55) occurred significantly more frequent in men (p = 0.035) as well as in patients younger than 60 at diagnosis (p < 0.001). Primary tumor sizes were significantly larger (p < 0.001), thereby resulting more frequently in a high-risk classification (OR = 4.53, CI 95% 2.41-8.52, p < 0.001). The 5-year rates of disease-specific survival (DSS), disease-free survival (DFS), and overall survival (OS) were 50.9%, 65.3% and 48.3%, respectively. The prognosis of esophageal GIST was less favorable compared with gastric GIST (DSS: p < 0.001, HR = 0.158, 95% CI: 0.087-0.288; DFS: p = 0.023, HR 0.466, 95% CI: 0.241-0.901; OS p = 0.003, HR = 0.481, 95% CI: 0.294-0.785; univariate Cox model) after a median follow-up time of 28 months (range 1.9 to 202). Mutational analysis for KIT showed more frequently wild-type status in esophageal GIST (OR = 10.13, CI 95% 3.02-33.96, p < 0.001). Conclusions: Esophageal GIST differ significantly from gastric GIST in respect to clinicopathological features and clinical outcome. To optimize treatment options further prospective data on patients with esophageal GIST are urgently warranted.