Risk of Metachronous Advanced Colorectal Neoplastic Among Individuals With Varying Numbers of Non-Advanced Adenomas Detected During Screening Colonoscopy

Risk of Metachronous Advanced Colorectal Neoplastic Among Individuals With Varying Numbers of Non-Advanced Adenomas Detected During Screening Colonoscopy: A Retrospective Observational Study

A retrospective observational study to evaluate the risk of metachronous advanced colorectal neoplastic (ACRN) among individuals with varying numbers of non-advanced adenomas (NAA) detected during screening colonoscopy

Study Overview

• Status: Completed
• Conditions: Colorectal Adenoma
• Intervention / Treatment: Other: No Intervention: Observational Cohort

Detailed Description

Colorectal cancer (CRC) is the third most commonly diagnosed malignancy worldwide and the second leading cause of cancer-related mortality. In recent years, with increasing westernization of diet and lifestyle, both the incidence and prevalence of CRC in China have risen sharply. CRC has become the most common gastrointestinal malignancy in the country, ranking second in incidence and fifth in mortality among all cancers. Screening colonoscopy and appropriate surveillance intervals can substantially reduce CRC-related deaths.

The latest 2020 U.S. Multi-Society Task Force (USMSTF) guidelines classify patients with 1-2 non-advanced adenomas (NAAs), 3-4 NAAs, and >4 NAAs as having low-, intermediate-, and high-risk colonoscopic findings, respectively, and recommend surveillance intervals of 7-10 years, 3-5 years, and 3 years for these groups. However, accumulating evidence suggests that the risk of developing metachronous advanced colorectal neoplastic lesions (ACRN) in individuals with 3-4 NAAs may be comparable to those with only 1-2 NAAs, raising concerns regarding the appropriateness of current surveillance recommendations.

Using a real-world, endoscopy database, this study systematically evaluates the association between different NAA counts and the subsequent risk of ACRN, providing evidence to inform optimization of post-polypectomy surveillance intervals.

• Study Type: Observational
• Enrollment (Actual): 2955

Contacts and Locations

Study Locations

• China
  • Shanghai Municipality
    • Shanghai, Shanghai Municipality, China, 200040
      • Huadong Hospital, Fudan University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Individuals who underwent their first-time screening colonoscopy between 2012 and 2023 at the endoscopy centers of Huadong Hospital and Shanghai Tongji Hospital, and who completed at least one surveillance colonoscopy.

Description

Inclusion Criteria:

• First-time screening colonoscopy
• Only non-advanced adenomas (no villous features, no high-grade dysplasia, and diameter <10 mm) were detected during first-time screening colonoscopy
• Individuals with at least one surveillance colonoscopy
• Complete electronic medical record and pathology information

Exclusion Criteria:

• Inadequate bowel preparation (BBPS < 6)
• Emergency colonoscopy
• History of colorectal cancer
• Incomplete pathology information or incompletely resected polyps
• Screening colonoscopies performed by endoscopists with a low dynamic adenoma detection rate (ADR < 15%)
• Follow-up duration < 6 months

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Individuals with <3 NAAs detected during screening colonoscopy; Individuals with <3 non-advanced adenomas detected during screening colonoscopy	Other: No Intervention: Observational Cohort; No Intervention: Observational Cohort
Individuals with 3-4 NAAs detected during screening colonoscopy; Individuals with 3-4 non-advanced adenomas detected during screening colonoscopy	Other: No Intervention: Observational Cohort; No Intervention: Observational Cohort
Individuals with >4 NAAs detected during screening colonoscopy; Individuals with >4 non-advanced adenomas detected during screening colonoscopy	Other: No Intervention: Observational Cohort; No Intervention: Observational Cohort

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Metachronous Advanced Colorectal Neoplasia	Metachronous advanced colorectal neoplasia is defined as advanced adenoma (≥10 mm, villous component, or high-grade dysplasia) or colorectal cancer detected at any follow-up colonoscopy after the baseline index colonoscopy.	Through study completion, an average of 1 month

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Metachronous Colorectal Neoplasia	Metachronous colorectal neoplasia is defined as any adenoma or colorectal cancer detected at any follow-up colonoscopy after the baseline index colonoscopy.	Through study completion, an average of 1 month

Collaborators and Investigators

• Sponsor: Fudan University
• Investigators: Study Director: Danian Ji, M.D., Huadong Hospital

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2025
• Primary Completion (Actual): September 30, 2025
• Study Completion (Actual): September 30, 2025

Study Registration Dates

• First Submitted: November 29, 2025
• First Submitted That Met QC Criteria: December 11, 2025
• First Posted (Actual): December 24, 2025

Study Record Updates

• Last Update Posted (Actual): December 24, 2025
• Last Update Submitted That Met QC Criteria: December 11, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Surveillance; Screening colonoscopy; Advanced colorectal adenoma
• Other Study ID Numbers: 2025K369

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All collected IPD
• IPD Sharing Time Frame: 1 year after completion of this study
• IPD Sharing Access Criteria: All researchers can require the original data from principal investigator of this study (Email address: arctg4@163.com)
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No