Retrospective Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 28, 2022; 28(48): 6950-6961
Published online Dec 28, 2022. doi: 10.3748/wjg.v28.i48.6950
Clinical features and long-term outcomes of patients with colonic oligopolyposis of unknown etiology
Dan Feldman, Linda Rodgers-Fouche, Stephanie Hicks, Daniel C Chung
Dan Feldman, Division of Gastroenterology, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
Linda Rodgers-Fouche, Stephanie Hicks, Center for Cancer Risk Assessment, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
Daniel C Chung, Division of Gastroenterology and Center for Cancer Risk Assessment, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, United States
Author contributions: Feldman D contributed to conceptualization and design, formal analysis and interpretation, investigation, resources and acquisition of data, methodology, visualization, writing, revising, and editing the draft critically for important intellectual content; Rodgers-Fouche L contributed to conceptualization, resources and acquisition of data, writing, revising, and editing the draft critically for important intellectual content; Hicks S contributed to conceptualization, resources and acquisition of data, writing, revising, and editing the draft critically for important intellectual content; Chung DC contributed to conceptualization and design, formal analysis and interpretation, investigation, methodology, resources and acquisition of data, supervision, visualization, writing - original draft, writing, revising, and editing the draft critically for important intellectual content; All authors have read and approve the final manuscript.
Institutional review board statement: IRB approval (No. 2016P000516) was obtained by the Massachusetts General Hospital (MGH), For Retrospective Review and analysis of data, specimens, and/or records using the Hereditary GI Cancer Database.
Informed consent statement: Because of the retrospective and anonymous character of this study, the need for informed consent was waived by the institutional review board.
Conflict-of-interest statement: All authors declare no conflicts-of-interest related to this article.
Data sharing statement: Data are not available due to patient privacy restrictions and the absence of consent for public sharing.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
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: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Daniel C Chung, MD. Medical Co-Director, Center for Cancer Risk Assessment. Director, High-Risk GI Cancer Clinic, GI Division, Massachusetts General Hospital, Blossom Street, Boston, MA 02114. United States. chung.daniel@mgh.harvard.edu
Received: October 2, 2022
Peer-review started: October 2, 2022
First decision: November 3, 2022
Revised: November 14, 2022
Accepted: December 13, 2022
Article in press: December 13, 2022
Published online: December 28, 2022
ARTICLE HIGHLIGHTS
Research background

Colonic polyposis syndromes typically result from germline mutations in the APC or MUTYH genes and less commonly from other low/intermediate-risk genes. When no pathogenic variant is identified, a diagnosis of colonic polyposis of unknown etiology (CPUE) is made.

Research motivation

The existing literature on CPUE is limited, and the precise clinical features and long-term outcomes are not well-defined.

Research objectives

To characterize the natural history of CPUE by defining the malignancy risk, long-term colonic adenoma burden, and risk of extra-colonic tumors over an extended period of surveillance.

Research methods

We performed a retrospective detailed chart review of demographic, lifestyle habits, endoscopic, genetic, and clinical data of patients aged 18 years old or older meeting the criteria for CPUE in the Hereditary Gastrointestinal Cancer Database at Massachusetts General Hospital.

Research results

70 patients met the inclusion criteria and were predominantly Caucasian males. During an extended surveillance period, a very low cumulative colonic adenoma burden was observed, with no evidence for duodenal adenomas. 4 patients were diagnosed with colorectal cancer (CRC), but none had extra-colonic malignancies that are typically seen in familial adenomatous polyposis (FAP) syndrome (i.e., gastric, duodenal, or thyroid cancer). There was no mortality attributable to CRC.

Research conclusions

Individuals with CPUE exhibited a relatively mild course with respect to polyp burden and cancer risk, which differs significantly from the FAP syndrome. The modest colonic burden implies colonoscopy surveillance intervals could be extended, and regular gastroscopic exams may not be necessary.

Research perspectives

CPUE is an underdiagnosed and heterogeneous clinical entity. The current findings should be validated in large-scale multi-center prospective studies, with greater representation of non-Caucasian populations in order to better define this unique condition in an evidence-based approach.