Abstract Library

#4618 The exceptionally rare phenomenon of well-differentiated colon neuroendocrine tumours

Introduction: Colonic neuroendocrine tumours (NETs), excluding rectal NETs, are often described as relatively common and aggressive, with inferior median survival compared to other gastrointestinal (GI) primary sites. However, epidemiological databases may conflate well-differentiated NETs with poorly differentiated NECs, leading to unclear data on prevalence, clinical behaviour, and prognosis of well-differentiated colonic NETs.

Conference:

Presenting Author: Al-Toubah T

Authors: Al-Toubah T, Strosberg J,

Keywords: colon, neuroendocrine tumour, caecum, sigmoid, neuroendocrine neoplasm,

#4282 A first-in-human phase I trial with antibody drug conjugate ADCT-701 in neuroendocrine tumours and carcinomas

Introduction: Neuroendocrine neoplasms (NENs) consist of neuroendocrine tumours and neuroendocrine carcinomas, which are rare malignancies found in various anatomical sites, including the gastrointestinal tract, pancreatic islets, lungs, and adrenal glands. Poorly differentiated NECs are classified as high-grade carcinomas that bear resemblance to small-cell lung cancer; however, these patients experience a high risk of relapse and demonstrate a limited response to additional systemic therapies. Adrenocortical carcinoma (ACC) is another rare cancer and currently, no targeted therapies have demonstrated significant effectiveness for this condition. Preclinical investigations have indicated that Delta-like non-canonical notch ligand 1 (DLK1) is expressed in various neuroendocrine neoplasms, including ACC, SCLC, neuroblastoma, pheochromocytoma, and paraganglioma.

Conference:

Presenting Author: Del Rivero J

Authors: Del Rivero J, Glod J, Magee T, Cooper K, Rivero A,

Keywords: NEN, NEC, NET, ACC, ADC, ADCT-701,

#4234 Association of long-term PPI use with low-risk gastric neuroendocrine tumor

Introduction: Gastric neuroendocrine tumors are rare neoplasms, comprising approximately 2% of all gastric tumors, and develop from enterochromaffin-like (ECL) cells in the gastric mucosa. Type I and II develop due to hypergastrinemia and ECL cell hyperplasia; type III typically occurs sporadically, tend to be more aggressive, present metastatically in > 50% of cases, have normal fasting gastrin levels, and vary histopathologically from well- to poorly differentiated.

Conference:

Presenting Author: Al-Toubah T

Authors: Al-Toubah T, Pelle E, Haider M, Strosberg J,

Keywords: gastric, ppi, neuroendocrine, type 3 gastric net,

#3558 Association of long-term PPI use with low-risk gastric neuroendocrine tumor

Introduction: Gastric neuroendocrine tumors are rare neoplasms, comprising approximately 2% of all gastric tumors and develop from enterochromaffin-like (ECL) cells in the gastric mucosa. Type I and II develop due to hypergastrinemia and ECL cell hyperplasia; type III typically occure sporadically, tend to be more aggressive, present metastatically in > 50% of cases, have normal fasting gastrin levels, and vary histopathologically from well- to poorly differentiated tumors.

Conference:

Presenting Author:

Authors: Al-Toubah T, Pelle E, Strosberg J,

Keywords: gastric carcinoid, ppi, gastric, NET, type 2, type 3, type 1,

#3120 Thinking and confusion about a well-differentiated grade 3 pancreatic neuroendocrine tumor

Introduction: In WHO Classification of Digestive System Tumors (2019 edition), pancreatic NENs are divided into well-differentiated NETs (including G1, G2, G3) and poorly differentiated NECs mainly based on the mitoses and Ki-67. G3 pNET and pNEC should have more than 20 mitoses/10 HPFs or their Ki-67 should be higher than 20%. However, WHO didn't clearly distinguish the Ki-67 cut-off value between them, and only 55% was recommended.

Conference: 18th Annual ENETS Concerence (2021)

Presenting Author: Ma Y

Authors: Ma Y, Song L, Li X, Yang M, Wang F,

Keywords: pancreatic neuroendocrine carcinoma, pancreatic neuroendocrine tumor, G3, P53, ATRX, DAXX, MEN1,