Gastrointestinal Stromal Tumors – Our Institutional 10-Year Experience

Abstract

Introduction/Objective Gastrointestinal stromal tumors (GIST), albeit very rare overall, with approximately 5,000 new diagnoses yearly in the US, represent the most common mesenchymal tumor involving the GI tract. particularly the stomach and small bowel. Pogress has been made in the past two decades in terms of describing pathogenesis, classification, and targeted therapy of GIST, however, their behavior is still quite challenging and unpredictable, and their prognosis remains guarded. Methods/Case Report We reviewed our institutional experience with GIST between 2010-2020; the review included surgical pathology reports, charts, and slides and we extracted data relevant for better characterization of these rare tumors. Results (if a Case Study enter NA) We identified a total of 53 GIST, with a preponderance of females (37 cases) versus males (16), and age ranging from 33yo (female) to 90yo (female). The majority of tumors were located in the stomach (39), with the remaining distributed between different locations: colon, small bowel, duodenum (3 each), esophagus and liver (2 each) and retroperitoneum (1). The GISTs ranged in size from 0.2 to 30 cm. 14 GISTs were smaller than 1 cm, with 8 of these being incidental findings: 4 associated with another tumor, 3 in sleeve gastrectomies, and 1 in a colon resected for perforated diverticulitis. Six GISTS were multiple, with 2-3 different tumors in the stomach, corresponding to a pT1m or pT2m stage. Majority of GISTs were spindled, while only 3 GISTwere mixed and 2 were epithelioid. All GIST in our review were c-kit positive. Conclusion In summary, we report data obtained from 53 resected GIST’s over a 10 year period. GIST ia a rare tumor overall, with an annual incidence of 10-20 new cases/ million, and therefore it is relatively difficult to study. Our findings confirm those reported in the literature as far as localization (preponderence of stomach), gender prevalence (female) and predominant proto-oncogen kit mutation, but shows a wider age range and interesting co-morbid associations in small, no risk GIST. These findings support the hypothesis that tumor microenvironment and host immune response are important factors in pathogenesis and provides empirical evidence that immunotherapy and immunomodulation should be studied as therapeutic additions in GIST.