Gastrointestinal Stromal Tumors (Gists) Of The Esophagus And Gastroesophageal Junction (Gej).

179Background: GISTs arise from interstitial cells of Cajal anywhere within the gastrointestinal tract, but those of the esophagus and GEJ are exceedingly rare ( u003c 1% of cases). Our aim was to characterize clinicopathological features and outcomes of esophageal and GEJ GISTs and compare survival with a population-based registry (SEER). Methods: 28 cases were identified using the Mayo Clinic Cancer Registry from 1997 to 2016, and 378 cases from the SEER 18 registry from 2000 to 2013. Mayo cases were re-reviewed by Mayo pathologists. We analyzed patient characteristics, tumor location, TNM staging, mitotic index, molecular diagnostics, IHC staining, and histomorphology. JMP software was used to calculate time to recurrence (TTR) and overall survival (OS) utilizing Kaplan-Meier and log-rank. Results: At Mayo, 60% of tumors arose in the distal esophagus. Mean tumor size was 5.73 cm. 42% of cases were low grade. None had nodal involvement. Five cases were metastatic at diagnosis, all to the liver. 86.7% had sp...