Abstract Library

#2991 Gastroenteropancreatic (GEP) Neuroendocrine Neoplasia G3 (NEN G3) According to 2019 WHO Classification: A Comprehensive Clinicopathological Characterization Including Mismatch Repair (MMR) Proteins, PDL1 Expression and KRAS/BRAF Status

Introduction: In the 2019 WHO FOR NEN’S classification NETG3 have been distinguished from poorly differentiated neuroendocrine carcinoma (NEC). They are heterogeneous group concerning prognosis and treatment benefit.

Conference: 17th Annual ENETSConcerence (2020)

Presenting Author:

Authors: Ruiz G, Graselli J, Golubicki M, Rizzol M,

Keywords: G3 NEN, PD-L1, KRAS, BIOMARKERS,

#2982 Comprehensive Molecular Analysis Identifies Driver Mutations in Metastases of Sporadic Well-Differentiated Neuroendocrine Tumours of the Small Intestine

Introduction: Small intestinal neuroendocrine tumours (SI-NETs) represent a heterogenous group of tumours. The molecular mechanisms which contribute to progression of SI-NETs are poorly elucidated. They are considered to be molecularly distinct from neuroendocrine carcinomas (NECs), which share oncogenic pathways with adenocarcinomas.

Conference: 17th Annual ENETSConcerence (2020)

Presenting Author: Samsom K

Authors: Samsom K, van Veenendaal L, Roepman P, Kodach L, Steeghs N,

Keywords: whole genome sequencing, neuroendocrine tumour, small intestine, genetics,

#2951 Analysis of Discordance between Biopsy Grade and Surgical Pathology Grade in Resected PanNEN Patients

Introduction: In PanNEN cases, treatment strategies are decided by tumor localization, volume and grade. In unresectable or metastatic cases, tumor grade is determined by biopsy specimen obtained from EUS-FNA and diagnostic accuracy of biopsy according to WHO classification 2017 is important for decision making of treatment.

Conference: 17th Annual ENETSConcerence (2020)

Presenting Author:

Authors: Nakano K, Masui T, Yogo A, Uchida Y, Nagai K,

Keywords: PanNEN, WHO classification 2017, EUS-FNA, Ki-67, biopsy, surgical pathology, discordance,

#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,

#2844 Rectal Neuroendocrine Tumor with Chromogranin Expression Is Associated with Aggressive Clinical Behavior and Worse Prognosis

Introduction: Although rectal neuroendocrine tumors (NETs) with L-cell phenotype and small tumor size generally had better clinical behavior, the new 2019 WHO classification classified all rectal NETs are malignant without considering L-cell phenotype and small tumor size. Therefore, identifying biomarkers of rectal NETs is important to stratify the clinical behavior of rectal NETs.

Conference: 17th Annual ENETSConcerence (2020)

Presenting Author: Kim J

Authors: Kim J, Kim J, Oh E, Yang D, Hong S,

Keywords: Rectal neuroendocrine tumor, Chromogranin, Immunohistochemistry, Prognosis,