Abstract

Background and Aims: Gastrointestinal stromal tumors (GISTs) are rare in pediatric patients, and they are not mostly caused by a pathogenic variant of the c-KIT gene unlike in adults. The most frequent localization is the stomach. Methods: Seventeen patients with a diagnosis of GIST were prospectively registered from 2000 to 2021 within the TREP project. Data about staging, diagnosis, treatment and follow-up were retrospectively reviewed. Results: The majoritywere female (10/17). Themean agewas 13.6 years, with 1 infant case. Main symptoms were anemia (14/17), gastrointestinal bleeding (5/17), and weakness (5/17). Fourteen patients had a gastric localization. Genetic testing revealed 3 patients with a germline c-KIT pathogenic variant, 2 with a PDGFRA variant, and 2 with a variant in the SDH gene (1/17 not tested; 1/17 evaluation in progress). Four had another tumor (paraganglioma, lung chondroma, esophageal leiomyioma), leading to suspect a Carney’s Triad. Twelve patients underwent surgery in first line (5 after initial biopsy) with curative intent (10) or to control symptoms (2), and 5/17 biopsy, followed by target therapy in first line in 4. Three of the latter received surgery; in two with curative intent and in the other for symptoms’ control. Three received adjuvant target therapy after primary surgery, and three after relapse. Six received more than one line of target therapy, and seven underwent multiple surgeries (including 2 liver transplants). Eleven patients are in complete remission, 2 are alive with disease, and 2 deceased (2 lost at follow-up). Conclusions: The data here presented in part confirm what already reported. We observed a higher rate of patients with Carney’s Triad. Surgery, thus having an important role, may be inadequate to cure the patients especially those with positive nodes. The role of target therapy can be hardly evaluated with such small numbers: larger international studies are warranted to improve these results.