Review
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Jul 15, 2020; 12(7): 705-718
Published online Jul 15, 2020. doi: 10.4251/wjgo.v12.i7.705
Pancreatic neuroendocrine tumors G3 and pancreatic neuroendocrine carcinomas: Differences in basic biology and treatment
Ming-Yi Zhang, Du He, Shuang Zhang
Ming-Yi Zhang, Shuang Zhang, Department of Biotherapy, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
Du He, Department of Pathology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
Author contributions: Zhang MY drafted the original manuscript and He D provided the images; Zhang S devised the original idea and critically reviewed the review.
Conflict-of-interest statement: Authors declare no conflict of interests for this article.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Shuang Zhang, MD, PhD, Associate Professor, Department of Biotherapy, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Gaopeng Street, No. 4, Keyuan Road, Chengdu 610041, Sichuan Province, China. shuang.zhang@scu.edu.cn
Received: December 31, 2019
Peer-review started: December 31, 2019
First decision: May 5, 2020
Revised: May 17, 2020
Accepted: June 17, 2020
Article in press: June 17, 2020
Published online: July 15, 2020
Processing time: 196 Days and 21.5 Hours
Abstract

In 2017 the World Health Organization revised the criteria for classification of pancreatic neuroendocrine neoplasms (pNENs) after a consensus conference at the International Agency for Research on Cancer. The major change in the new classification was to subclassify the original G3 group into well-differentiated pancreatic neuroendocrine tumors G3 (pNETs G3) and poorly differentiated pancreatic neuroendocrine carcinomas (pNECs), which have been gradually proven to be completely different in biological behavior and clinical manifestations in recent years. In 2019 this major change subsequently extended to NENs involving the entire digestive tract. The updated version of the pNENs grading system marks a growing awareness of these heterogeneous tumors. This review discusses the clinicopathological, genetic and therapeutic features of poorly differentiated pNECs and compare them to those of well-differentiated pNETs G3. For pNETs G3 and pNECs (due to their lower incidence), there are still many problems to be investigated. Previous studies under the new grading classification also need to be reinterpreted. This review summarizes the relevant literature from the perspective of the differences between pNETs G3 and pNECs in order to deepen understanding of these diseases and discuss future research directions.

Keywords: Neuroendocrine neoplasms, Pancreatic neuroendocrine tumors G3, Pancreatic neuroendocrine carcinomas, Gene sequencing, Clinical management, Histopathology

Core tip: The major change in the 2017 World Health Organization (WHO) classification of pancreatic neuroendocrine neoplasms was to further subclassified the original G3 group into pancreatic neuroendocrine tumors G3 (pNETs G3) and pancreatic neuroendocrine carcinoma (pNEC). In 2019 this major change subsequently extended to neuroendocrine neoplasms involving the entire digestive tract. This review comprehensively summarizes the differences between pNET G3 and pNEC, which is the major update in latest WHO grading classification for pancreatic neuroendocrine neoplasms by the aspects of histology, gene mutation, and clinical management.