Endocrine Abstracts

JOINT1523

Introduction: The aim of this work is to present our department’s experience with gastric neuroendocrine tumors (gNETs). The series of cases is comprised of 12 patients diagnosed with gastric NETs over a period of 15 years, from 2010 to 2025. A female predominance was observed, with a female/male ratio of 3:1.

Methods and results: According to literature, there are three main categories of gNETs, defined by the underlying gastric pathology. In our cohort, there were 8 patients diagnosed with type 1 gastric NETs (66.7%), one patient with type 2 (8.33%) and 3 patients with sporadic type 3 gNETS (25%). Type 1 gNETs are characterized by elevated gastrin levels in the context of autoimmune atrophic gastritis. All 8 patients had positive anti-parietal cell antibodies, decreased levels of vitamin B12 and hypergastrinemia, as well as elevated levels of chromogranin A. The median age at diagnosis was 58.5 years and 5 patients (62.5%) are still undergoing regular follow-up at our clinic. The majority of our patients with type 1 gastric NETS (87.5%) had multiple infra-centimetric lesions, with indolent evolution throughout follow-up, without loco-regional lymphadenopathy or distant metastasis, which is similar with data from literature. One patient (12.5%) had a singular lesion of over 2 cm diameter, with hepatic metastases present at diagnosis and G2 grading (Ki67=8%), which responded favorably to somatostatin analogue therapy and is currently monitored at 6 months interval. Five patients (62.5%) had a G2 grading and 3 patients (37.5%) had G1 tumors. One patient was diagnosed with type 2 gastric NETs in the context of multiple endocrine neoplasia type 1 (MEN 1). The initial evaluation showed multiple infra-centimetric G2 tumors (Ki67=3%) and hypergastrinemia. The patient underwent total gastrectomy, with subsequent normalization of biochemical markers. We also included 3 patients with type 3 gastric NETs, all of whom had, at initial evaluation, large tumors of over 3 cm and metastases to the liver, lung or peritoneum. Two patients had G2 gastric NETs and one had a G3 tumor (Ki67=70%). All patients received chemotherapy.

Conclusion: Our results corresponded to data from larger studies. Gastric NETs consist of three subtypes with distinct behavior and treatment. The only type 2 case occurred in the context of MEN1 syndrome. Type 1 tumors had an indolent evolution, whereas the type three ones were sporadic, larger and aggressive.