S1222 Increased Risk of Gastrointestinal and Extra-Intestinal Malignancies Among Patients Diagnosed With GIST During EGD: A Multi-Center Propensity-Matched Analysis

Introduction: Gastrointestinal stromal tumors (GISTs) are rare mesenchymal neoplasms often detected incidentally during upper endoscopy. While GISTs are associated with malignant potential, their link to other cancers is not well-defined. This study examined the risk of subsequent gastrointestinal and/or extraintestinal cancers in patients diagnosed with GIST during esophagogastroduodenoscopy (EGD). Methods: We conducted a retrospective multi-center propensity-matched analysis using TriNetX, a global database of de-identified electronic patients' health records. Adults who underwent EGD between October 2015 and October 2024 were identified. Individuals diagnosed with GIST within 1 year of EGD were compared to those with no GIST diagnosis. A 1:1 propensity-matched analysis was conducted for 2143 patients in each group, controlling for age, sex, race, and ethnicity. Outcomes were assessed over a 3-year period, excluding patients with prior diagnoses of outcome malignancies. Results: Demographics were well-balanced after matching. The mean age was 65.0 ± 13.2 years in the GIST group and 64.1 ± 14.9 in the non-GIST group. Female sex accounted for 53.1% of both groups; 58.6% were White and 19.2% Black. GIST patients showed a significantly increased risk of different types of malignanacies. Conclusion: Patients diagnosed with GIST during EGD have a significantly elevated risk of multiple cancers, particularly involving the stomach, small bowel, and colon. These findings highlight the need for established surveillance in patients with GIST identified during routine EGD, along with a better understanding of demographic predictors of GISTs.