Abstract Library

#3712 Germline pathogenic variants in patients with high-grade gastroenteropancreatic neuroendocrine neoplasms

Introduction: High-grade gastroenteropancreatic (HG-GEP) neuroendocrine neoplasms (NEN) are aggressive cancers with a dismal prognosis. The molecular etiology remains poorly characterized and prevalence of pathogenic germline variants unknown.

Conference:

Presenting Author: Sorbye H

Authors: Sorbye H, Venizelos A, Perren A, Couvelard A, Hjortland G,

Keywords: germline, mutations, gastropancreatic, neuroendocrine carcinoma, NET G3, high-grade,

#3631 Are hemicolectomies still indicated in patients with neuroendocrine tumors of the appendix 1-2cm? A retrospective Europe-wide cohort study

Introduction: Awareness of a potential global overtreatment by performing oncological resections for appendiceal neuroendocrine tumors (aNET) 1-2cm is increasing.

Conference:

Presenting Author: Nesti C

Authors: Nesti C, Bräutigam K, Zwahlen M, Perren A,

Keywords: appendix, neuroendocrine tumor, surgery, hemicolectomy, metastasis, survival,

#3486 Treatment response and survival according to molecular alterations in 229 patients with high-grade gastroenteropancreatic neuroendocrine neoplasms (HG GEP-NEN)

Introduction: HG GEP-NEN consist of well-differentiated neuroendocrine tumors (NET G3) and poorly differentiated neuroendocrine carcinoma (NEC). The majority have advanced disease, limited treatment options and a poor prognosis.

Conference:

Presenting Author: Elvebakken H

Authors: Elvebakken H, Venizelos A, Perren A, Couvelard A, Lothe I,

Keywords: neuroendocrine neoplasm, neuroendocrine carcinoma, high-grade, gastroenteropancreatic, molecular alteration, molecular marker,

#3388 Epigenetic progression steps in alpha-lineage MEN1-DAXX/ATRX mutated Pancreatic Neuroendocrine Tumors (PanNET)

Introduction: Recently, based on DNA methylation profiles, we have hypothesized that PanNETs with mutations in ATRX, DAXX and MEN1 originate from α-cells. Alpha-like PanNETs, small and indolent, were enriched for mutations in MEN1 only, while epigenetically intermediate PanNETs, larger and with high relapse risk, showed mutations in both MEN1 and DAXX/ATRX (Int-ADM). Int-ADM PanNETs show progressive loss of alpha cell differentiation.

Conference:

Presenting Author: Marinoni I

Authors: Di Domenico A, Kirchner P, Maire R, Thirlwell C, Perren A,

Keywords: Epigenetics, DAXX/ATRX, PanNET, PanNET progression,

#2936 Mutational Landscape of 109 High-Grade Gastroenteropancreatic Neuroendocrine Neoplasms G3

Introduction: Gastroenteropancreatic (GEP) neuroendocrine neoplasms (NEN) G3 are rare with a poor outcome. Molecular data for GEP NEN G3 is limited and the 2019 WHO classification is based on morphology and proliferation rate.

Conference: 17th Annual ENETSConcerence (2020)

Presenting Author: Elvebakken H

Authors: Venizelos A, Elvebakken H, Perren A, Hjortland G, Sundlöv A,

Keywords: molecular genetics, neuroendocrine carcinoma, neuroendocrine tumors, gastroenteropancreatic, mutations,