433P - Enhancer of zest homolog 2 (EZH2) expression in well and moderately differentiated pancreatic neuroendocrine tumor (pNET)

Date 08 October 2016
Event ESMO 2016 Congress
Session Poster Display
Topics Neuroendocrine Tumours
Presenter Riccardo Marconcini
Citation Annals of Oncology (2016) 27 (6): 136-148. 10.1093/annonc/mdw369
Authors R. Marconcini1, P. Faviana2, D. Campani2, L. Galli1, A. Antonuzzo3, C. Orlandini1, A. Falcone1, S. Ricci3
  • 1U.o. Oncologia Medica 2 Universitaria, Azienda Ospedaliera Universitaria S.Chiara, 56100 - Pisa/IT
  • 2U.o. Anatomia Patologica, Azienda Ospedaliera Cisanello Pisa, Pisa/IT
  • 3U.o. Oncologia Medica 1 Ospedaliera, Azienda Ospedaliera Universitaria S.Chiara, 56100 - Pisa/IT



Enhancer of zest homolog 2 (EZH2) is the catalytic subunit of polycomb repressive complex 2 with histone H3 methyltransferase function. EZH2 has been shown to be over-expressed in several malignant neoplasms and to be associated with aggressive behavior. Few data are currently available for NETs. EZH2 represents a potential therapeutic target and EZH2 inhibitor drugs are in development. In this study, we evaluated EZH2 expression in well differentiated G1 (Ki67


Immunohistochemical analyzes for nuclear EZH2 expression were performed using a commercially available detection kit on removed primary tumor tissue. We assessed the percentage of positive tumor cells. we considered negative score if expression was positive in less than 10% cells. We used the Chi Square test to compare the expression of EZH2 in the different groups. Histopathological data and clinical data pNET were also collected.


Thirty patients with pNET have been assessed (9 G1 and 21 G2 pNET). Eleven patients had metachronous metastases at median time of 49 (15-114) months, 8 patients had synchronous metastases and 11 patients had primary tumor radically removed without recurrence of disease. EZH2 was overexpressed in both G1 and G2 pNET: we found no significant difference of EZH2 expression between G1 and G2 pNET. In metastatic patients, negative score (


EZH2 is expressed in pNET. Data show a statistically significant difference in the expression of EZH2 between groups with metachronous metastases (more indolent clinical course), and the group with synchronous metastases (more aggressive clinical course), with lower expression in the first group. This data could be interesting in terms of therapeutic strategy. Further analisis are currently in progress in a larger group of NET patients. Investigation of EZH2 inhibitor drugs in pNET appear feasible

Clinical trial identification

Legal entity responsible for the study

Azienda Ospedaliera Universitaria Pisana


Foundation Aprio


All authors have declared no conflicts of interest.