Piecemeal Resection and Advanced Histology Independently Predict Local Recurrence After Colorectal Snare-based Endoscopic Resection: a Time-to-event Cohort Study

February 24, 2026 updated by: Ricardo Ribeiro Correa Filho, University of Sao Paulo

The objective of this retrospective cohort observational study is to identify variables related to the recurrence of colorectal lesions after snare polypectomy resection in colonoscopies. It also aims to evaluate the safety of the procedure. The main questions to be answered are:

  • What endoscopic characteristics are most related to recurrence?
  • What adverse events are related to the procedure?

The researchers will perform a chart analysis looking for demographic, clinical, endoscopic, and histological variables in order to identify which factors are most closely linked to the recurrence of previously resected lesions.

Study Overview

Status

Completed

Conditions

Detailed Description

  1. Scientific Basis Endoscopic resection represents one of the main strategies for preventing colorectal cancer, significantly reducing the incidence and mortality associated with the disease. Snare polypectomy, with or without the use of thermal energy (cold snare or hot snare), is widely used in clinical practice due to its efficacy, applicability, and favorable safety profile.

    However, despite the high initial success rate, local recurrence at the resection site remains a relevant clinical outcome, especially in larger lesions, piecemeal resections, and cases with advanced histological characteristics. The literature shows heterogeneity regarding independent predictors of recurrence, particularly when analyzed using time-to-event methodology.

    Given this scenario, it becomes essential to identify clinical, endoscopic, and histopathological variables associated with local recurrence, allowing for better risk stratification and optimization of surveillance protocols.

  2. Objectives

    Primary Objective:

    To identify variables associated with local recurrence after loop colorectal polypectomy.

    Secondary Objectives:

    To evaluate the occurrence of metachronous adenomas; To assess the safety of the procedure through the analysis of related adverse events; To determine independent predictors of recurrence using time-to-event analysis;

  3. Study Design Type: Retrospective observational cohort. Analytical model: Longitudinal study with time-to-event analysis. Center: Tertiary referral center. Inclusion period: 2023 to 2025. Sample: 255 consecutive adult patients. Essential criterion: Undergoing at least one surveillance colonoscopy after initial polypectomy.

  4. Study Population

    Inclusion Criteria:

    Patients ≥18 years; Underwent snare colorectal polypectomy (with or without thermal energy); Availability of histopathological examination; At least one documented follow-up colonoscopy;

    Exclusion Criteria:

    Resection by non-loop-based techniques (e.g., isolated ESD); Absence of endoscopic follow-up; Incomplete clinical or histological data;

  5. Characterization of the Lesions

    The lesions were described according to:

    Size: dichotomized into

    • <10 mm;
    • ≥10 mm; Location: right colon, transverse colon, left colon, or rectum. Morphological classification: according to the Paris Classification.

    Resection technique:

    • En bloc;
    • Piecemeal;

    Histopathology:

    • Tubular adenoma;
    • Tubulovillous adenoma;
    • Villous adenoma;
    • Serrated lesions;
    • Intramucosal carcinoma; * Advanced histology: defined as the presence of high-grade dysplasia and/or intramucosal adenocarcinoma.

  6. Outcomes 6.1 Primary Outcome Local recurrence, defined as endoscopic identification and histological confirmation of neoplastic tissue at the site of previous resection during surveillance colonoscopy.

    6.2 Secondary Outcomes Metachronous adenoma: development of a new lesion at a site distinct from the initial resection.

    Adverse events related to the procedure, including:

    • Immediate bleeding;
    • Delayed bleeding;
    • Perforation;
    • Post-polypectomy syndrome;
    • Need for hospitalization;
    • Need for surgical intervention;

  7. Data Collection

    The following variables were collected:

    7.1 Clinical

    • Age;
    • Sex;
    • Comorbidities;
    • Indication for colonoscopy;

    7.2 Endoscopic

    • Lesion size;
    • Location;
    • Morphology;
    • Resection technique (en bloc vs. piecemeal);

    7.3 Histological

    • Histological type;
    • Degree of dysplasia;
    • Presence of intramucosal carcinoma;
    • Classification as advanced histology;

  8. Statistical Analysis

    • The study was structured as a time-to-event analysis;
    • Estimation of cumulative recurrence incidence;
    • Kaplan-Meier curves for recurrence-free time analysis;
    • Comparison between groups using the log-rank test;
    • Cox regression models to identify independent predictors of recurrence;
    • Hazard Ratio (HR) calculation with 95% CI;
    • Significance level: p < 0.05;
  9. Relevant Methodological Aspects Consecutive inclusion to reduce selection bias. Standardization of endoscopic reports. Histopathological review according to institutional criteria. Objective definition of recurrence (histological confirmation).
  10. Expected Impact

This study will allow:

  • Identification of independent factors associated with local recurrence;
  • Better definition of the role of advanced histology as a risk marker;
  • Improvement of post-polypectomy surveillance intervals;
  • Consolidation of safety data in a real-world practice setting;
  • Contribution to the individualization of endoscopic follow-up.

Study Type

Observational

Enrollment (Actual)

255

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Brazil
    • São Paulo
      • Ribeirão Preto, São Paulo, Brazil, 14048-900
        • Hospital das Clínicas of Ribeirão Preto Medical School

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The study population consisted of 255 consecutive adult patients (≥18 years) who underwent loop colorectal polypectomy, with or without the use of thermal energy, at a tertiary referral center between 2023 and 2025. Only individuals with available histopathological examination of the resected lesion and who had undergone at least one documented surveillance colonoscopy, allowing evaluation of the previous resection site, were included. Patients who underwent advanced non-loop-based techniques, those without endoscopic follow-up, and cases with incomplete clinical or histological data were excluded, ensuring methodological homogeneity and adequate measurement of outcomes.

Description

Inclusion Criteria:

  • Age ≥ 18 years at the time of polypectomy;
  • Underwent snare polypectomy, with or without the use of thermal energy (cold snare or hot snare), performed during the study period (2023-2025);
  • Procedure performed at a participating tertiary center, ensuring technical and record standardization;
  • Availability of histopathological examination of the resected lesion, allowing for adequate histological characterization;
  • Performance of at least one documented surveillance colonoscopy, with evaluation of the previous resection site;
  • Adequate recording of clinical and endoscopic variables necessary for analysis (lesion size, location, resection technique, etc.);

Exclusion Criteria:

  • Patients undergoing techniques other than loop polypectomy, such as: Endoscopic submucosal dissection (ESD), advanced mucosal resection not based on conventional loop, primary surgical resection of the lesion;
  • Absence of follow-up colonoscopy, making it impossible to assess the primary outcome (local recurrence);
  • Incomplete clinical, endoscopic, or histopathological data that prevent adequate classification of study variables;
  • Invasive lesions beyond the mucosa (invasive cancer with deep submucosal invasion) that have been referred for immediate surgical treatment without endoscopic follow-up;
  • Loss to follow-up before the first surveillance colonoscopy.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Local recurrence of the lesion at the site of the previous resection
Time Frame: Between the years 2023 and 2025.
Presence of a visible lesion at the scar site of a previous polypectomy, histologically confirmed as adenomatous, serrated, or neoplastic tissue, obtained by biopsy or new resection.
Between the years 2023 and 2025.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Presence of metachronous adenoma
Time Frame: Between the years 2023 and 2025.
Development of a new adenomatous or serrated lesion at a site different from the area of previous resection, identified during follow-up colonoscopy and confirmed histologically.
Between the years 2023 and 2025.
Adverse events related to the procedure
Time Frame: Between the years 2023 and 2025.
Complications attributable to snare polypectomy, classified as: immediate bleeding; delayed bleeding; perforation; post-polypectomy syndrome (when applicable); and need for hospitalization or surgical intervention.
Between the years 2023 and 2025.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Sao Paulo

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 4, 2025

Primary Completion (Actual)

January 15, 2026

Study Completion (Actual)

February 24, 2026

Study Registration Dates

First Submitted

February 24, 2026

First Submitted That Met QC Criteria

February 24, 2026

First Posted (Actual)

March 3, 2026

Study Record Updates

Last Update Posted (Actual)

March 3, 2026

Last Update Submitted That Met QC Criteria

February 24, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 8.027.384
  • 94262925.8.0000.5440 (Other Identifier: Research Ethics Committee of the Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

The individual patient data included in this study will not be shared with other researchers, as it contains sensitive clinical information obtained through medical record review and is protected by ethical and legal standards of confidentiality and data protection. Even after anonymization, sharing could represent a residual risk of re-identification, especially since it is a sample from a single center with specific clinical characteristics. Therefore, the restriction on external sharing aims to guarantee the privacy of participants, compliance with the guidelines of the Research Ethics Committee, and conformity with current data protection legislation.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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