Management Strategies and Outcomes for Type 1 Gastric Neuroendocrine Tumors Measuring>1cm in Diameter

E Dell'Unto; R Srirajaskanthan; A Saini; G Salin; L De Mestier; C Toumpanakis; D Mandair; D O'toole; B Neary; D Campana; M Pritchard; F Panzuto

doi:10.1055/s-0045-1805658

Endoscopy, Table of Contents

Endoscopy 2025; 57(S 02): S270
DOI: 10.1055/s-0045-1805658

Abstracts | ESGE Days 2025

Moderated poster

UGI Diagnostics 05/04/2025, 09:30 – 10:30 Poster Dome 1 (P0)

Management Strategies and Outcomes for Type 1 Gastric Neuroendocrine Tumors Measuring>1cm in Diameter

Authors

E Dell'Unto

¹Department of Medical-Surgical Sciences and Translational Medicine, Sapienza University of Rome, Rome, Italy

²Digestive Disease Unit, ENETS Center of Excellence, Sant’Andrea University Hospital, Rome, Italy
R Srirajaskanthan

³Department of Gastroenterology, Kings College Hospital, London, United Kingdom
A Saini

³Department of Gastroenterology, Kings College Hospital, London, United Kingdom
G Salin

⁴Université Paris Cité, Department of Pancreatology and Digestive Oncology, Beaujon Hospital, Paris, France
L De Mestier

⁴Université Paris Cité, Department of Pancreatology and Digestive Oncology, Beaujon Hospital, Paris, France
C Toumpanakis

⁵Neuroendocrine Tumour Unit, ENETS Centre of Excellence, Royal Free Hospital, London, United Kingdom
D Mandair

⁵Neuroendocrine Tumour Unit, ENETS Centre of Excellence, Royal Free Hospital, London, United Kingdom
D O'toole

⁶National Centre for NETs, ENETS CoE, St. Vincent's University Hospital, Dublin, Ireland
B Neary

⁶National Centre for NETs, ENETS CoE, St. Vincent's University Hospital, Dublin, Ireland
D Campana

⁷Alma Mater Studiorum – Università di Bologna, Bologna, Italy
M Pritchard

⁸Department of Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool, United Kingdom
F Panzuto

¹Department of Medical-Surgical Sciences and Translational Medicine, Sapienza University of Rome, Rome, Italy

²Digestive Disease Unit, ENETS Center of Excellence, Sant’Andrea University Hospital, Rome, Italy

Abstract

Full Text

Aims Type 1 gastric neuroendocrine tumors (T1-gNETs) are well-differentiated, typically indolent neoplasms associated with chronic atrophic gastritis (CAG) and hypergastrinemia, with nearly 100% long-term survival. However, they have a high recurrence rate of 30-60% within the first year after resection. Tumor size is the most critical prognostic factor, while the role of grading is less definitive compared to other digestive NETs. International guidelines recommend conservative management for tumors<1 cm, advocating for approaches such as endoscopic resection or surveillance, which have shown excellent outcomes. However, the management strategies and outcomes for tumors>1 cm remain less clearly defined due to the lack of scientific data in this specific patient population. This study aims to investigate the management and outcome of patients with T1-gNETs>1cm.

Methods This multicenter retrospective study included patients with well-differentiated T1-gNETs>1cm, with at least 12 months of follow-up. The primary endpoint was disease progression (DP) (tumor recurrence or metastasis development), and Cox regression method was used to identify factors associated with progression.

Results The study included 71 patients (44 females, 27 males) with a median age of 61 years and a median tumor size of 18 mm (11–54). 64.8% of tumors were classified as G1, 33.8% as G2 and 1.4% as G3. 60 patients (84.5%) underwent endoscopic resection (17 EMR, 5 m-EMR, 14 ESD, 7 snare polypectomy, and 17 unspecified techniques). 19 patients (26.7%) underwent surgical procedures (10 with previous endoscopic resection), while 2 patients (2.8%) received no treatment. The R0 resection rate was 49.3%. During follow-up, 22 patients (31%) experienced recurrence, 7 (9.8%) developed metastases and 1 (1.4%) died of non-tumor-related causes. The median overall survival and progression-free survival were 56 (10–214) and 47 (2–211) months, respectively. Univariate analysis showed that R0 resections (HR 0.36, p=0.01) and advanced endoscopic techniques (m-EMR/ESD) (HR 0.10, p=0.0028) were associated with better outcomes. Conversely, other resection methods (standard-EMR/snare polypectomy/unspecified) were associated with a higher risk of DP (HR 9.22, p=0.0028).

Conclusions T1-gNETs>1cm often recur and can progress, showing potential aggressive behaviour. Endoscopic resection should use advanced techniques to avoid incomplete removal, linked to poor outcomes.