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

#1780

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.

Aim(s): As DAXX/ATRX mutated pNET have chromosomal instability, this could lead to presence or novel epitopes and increased PD-L1 expression, the inhibition of which would be a potential therapy.

Materials and methods: We studied 117 resected pNET for PD-L1 expression by IHC (Cell Signaling, Clone E1L3N). Membranous staining using a scoring intensity (0, 1, 2) in >5% of cells was evaluated. PD-L1 expression was correlated to stage, grade, Ki-67, and presence/absence of DAXX/ATRX mutations.

Conference: 14th Annual ENETSConcerence (2017)

Presenting Author: Saganas C

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

Keywords: neuroendocrine, tumors,