Abstract Library

#1780 PD-L1 Is Expressed in a Subset of Pancreatic Neuroendocrine Tumors (pNET)

Introduction: Programmed death 1 (PD-1) is an immune inhibitory receptor expressed on several immune cells, interacting with two ligands, PD-L1 and PD-L2. The former is expressed in many human cancers and is used as a selection criterion for indication of checkpoint inhibitor therapies. PD-L1 is also a potential target for checkpoint inhibitors in pNET therapy, however no data on prevalence of PD-L1 expression and potential associations to clinico-pathologic features is available.

Conference: 14th Annual ENETSConcerence (2017)

Presenting Author: Saganas C

Authors: Saganas C, Blank A, Franzelli M, Marinoni I, Perren A,

Keywords: neuroendocrine, tumors,

#1523 Multiregion Analysis Reveal Evolutionary Patterns and a Chromosomal Instability Signature in Pancreatic Neuroendocrine Tumours

Introduction: Pancreatic neuroendocrine tumors (PNETs) are potentially lethal diseases that show variable degrees of proliferation and invasiveness. Although genetic subgroups have been suggested to give prognostic information the impact of clonal evolution to the development and outcome of PNETs remains unexplored.

Conference: 13th Annual ENETSConcerence (2016)

Presenting Author: Crona J

Authors: Crona J, Backman S, Kugelberg J, Maharjan R, Björklund P,

Keywords: Cancer evolution, Molecular genetics, Neuroendocrine Tumor,

#1312 Epigenetic Remodeling upon DAXX and ATRX Loss in Pancreatic Neuro-endocrine tumors (pNETs)

Introduction: DAXX and or ATRX loss occur in 40% of sporadic pNETs. DAXX and ATRX participate in the cell epigenetic status maintenance. Epigenetic changes influence gene expression, function of telomeres and genomic stability. We hypothesize that DAXX/ATRX loss drives tumor progression in pNET through epigenetic changes affecting genomic stability.

Conference: 13th Annual ENETSConcerence (2016)

Presenting Author:

Authors: Marinoni I, Wiederkeher A, Pantasis S, Normand L, Wiedmer T,

Keywords: DAXX/ATRX, epigenetic, CIN,

#1245 Identification of Response Predictors to Temozolomide-Based Chemotherapy

Introduction: Capecitabine and temozolomide are active in the treatment of metastatic pNETs, with response rates ranging from 30% to 70%. Several small retrospective series have suggested that MGMT deficiency may predict response to temozolomide, however expression of MGMT has not been validated as a predictive biomarker. Cytotoxic chemotherapy is thought to be most active in aggressive tumors, however the ki-67 index has not been formally evaluated as a predictive factor. It is unclear whether chromosomal instability (which correlates with alternate lengthening of telomeres) predicts response.

Conference: 12th Annual ENETSConcerence (2015)

Presenting Author: Strosberg J

Authors: Strosberg J, Cives M, Brelsford M, Black M, Meeker A,

Keywords: ki67, MGMT, ALT, chromosomal instability, temozolomide, capecitabine, pNET,

#856 DAXX and ATRX Loss Defines Chromosomal Instability and Poor Outcome in Pancreatic NET

Introduction: Chromosomal Instability (CIN) has been reported in pancreatic neuroendocrine tumors (pNETs) with poor outcome. However, no specific genetic background has been associated with CIN. Whole exome sequencing revealed mutations in DAXX (Death domain associated protein gene) and ATRX (ATR-X gene) in 40% of pNETs. DAXX and ATRX mutations in pNETs are associated with Alternative Lengthening of Telomeres (ALT) activation.

Conference: 11th Annual ENETSConcerence (2014)

Presenting Author:

Authors: Marinoni I, Schmitt A, Vassella E, Dettmer M, Rudolph T,

Keywords: pNET, Daxx, Atrx, ALT, CIN,