Abstract Library

#4544 Spatial and temporal intratumour heterogeneity of pancreatic neuroendocrine tumours (PanNET)

Introduction: Data derived from the study of intertumour heterogeneity have led to propose that PanNET evolution may start either from beta cells with good prognosis, or from alpha cells with sequential alterations of MDA (MENIN-DAXX/ATRX) leading to more aggressive lesions.

Conference:

Presenting Author: Awan Z

Authors: Awan Z, Bourdeleau P, Epée J, Ps H, Tihy M,

Keywords: Pancreatic neuroendocrine tumour, Heterogeneity, Tumour microenvironment,

#4130 CHGA and DAXX/ATRX expression influence the outcome of pancreatic head neuroendocrine tumors

Introduction: In the past two years a difference between pancreatic neuroendocrine tumors (pNET) located in the head and body/tail regarding biological characteristics and clinical outcomes was described.

Conference:

Presenting Author: Amin T

Authors: Amin T, Viol F, Awwad F, Fründt T, Fraune C,

Keywords: neuroendocrine tumor, pancreatic, DAXX/ATRX, OS,

#3752 Loss of protein expression of tumor suppressor genes in neuroendocrine tumors – A tissue microarray analysis of 201 tumors from various organ sites

Introduction: Neuroendocrine tumors (NET) are a heterogenous group of tumors which differ in outcome based on their primary site. So far, data on inactivation of tumor suppressor genes in NET are mainly based on pancreatic and small intestine NET (pNET, siNET), whereas NET from other organ sites have not rigorously been analysed.

Conference:

Presenting Author:

Authors: Amin T, Viol F, Fründt T, Krause J, Fraune C,

Keywords: TMA, DAXX/ATRX, tumor suppressor, neuroendocrine tumor,

#3608 Endoscopic ultrasound fine-needle biopsy to assess DAXX/ATRX expression and alternative lengthening of telomeres status in non-functional pancreatic neuroendocrine tumors

Introduction: Death domain-associated protein (DAXX) and/or α-thalassemia/mental retardation X-linked (ATRX) chromatin remodelling genes mutations and alternative lengthening of telomeres (ALT) activation are associated with more aggressive behaviour of non-functional pancreatic neuroendocrine tumors (NF-pNETs).

Conference:

Presenting Author:

Authors: Mastrosimini M, Manfrin E, Remo A, de Bellis M, Pedron S,

Keywords: pancreatic tumor, ALT, FISH, immunohistochemistry,

#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,