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,

#4572 Steroid dosing to prevent tumour flare reaction with 177Lu-DOTATATE

Introduction: Tumour flare reactions including increased pain and small bowel obstruction (SBO) have been reported in patients with somatostatin receptor (SSTR)-positive gastroenteropancreatic neuroendocrine tumours (GEP-NETs) receiving 177Lu-DOTATATE. Retrospective reviews report tumour flare reactions in 6 to 40 percent of high-risk patients receiving 177Lu-DOTATATE and report success with using corticosteroid prophylaxis to prevent tumour flare recurrence with subsequent doses of 177Lu-DOTATATE (Strosberg, et al., 2021; Salner, et al., 2020).

Conference:

Presenting Author:

Authors: Cass A, Skotte E, Wheless M, Stockton S, Ramirez R,

Keywords: 177Lu-DOTATATE, corticosteroid prophylaxis, tumour flare,

#4518 Efficacy and safety of cabozantinib (CABO) for advanced Grade 3 (G3) neuroendocrine tumours (NETs) after progression on prior therapy: Subgroup analysis of the phase III CABINET trial (Alliance A021602)

Introduction: Well-differentiated G3 NETs have been described as a distinct category recently, and randomised data regarding efficacy of therapy are scarce. In the phase 3 CABINET trial (NCT03375320), CABO significantly prolonged progression-free survival (PFS) compared with placebo (PB) in patients (pts) with advanced, previously treated, progressive well-differentiated extra-pancreatic NETs (epNETs) and pancreatic NETs (pNETs) of all grades (Chan et al., NEJM, 2024).

Conference:

Presenting Author: Strosberg J

Authors: Strosberg J, Zemla T, Geyer S, Pulsipher S, Behr S,

Keywords: cabozantinib, grade 3 neuroendocrine tumour, pancreatic neuroendocrine tumour, extra-pancreatic neuroendocrine tumour,

#4236 Do metastatic appendiceal NETs ever develop metachronously after appendectomy or right hemicolectomy?

Introduction: Appendiceal NETs are typically detected incidentally during appendectomy. A recent study reported no cases of metachronous metastases among patients (pts) with primary tumors

Conference:

Presenting Author: Al-Toubah T

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

Keywords: appendiceal net, appendix net, neuroendocrine tumor, right hemicolectomy, appendectomy,

#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,