Study on Second Forward View Examination in the Right Colon

Comparison of Second Forward View Examination and Conventional Withdrawal Examination in the Right Colon on Polyp Detection in Screening and Surveillance Colonoscopies: A Randomized Controlled Study (SFVRC Study)

It is estimated that there are about 1.4 million patients with colorectal cancer (CRC) worldwide, with a rising trend in CRC incidence in many Asian Pacific countries. In Hong Kong, colorectal cancer ranks first in cancer incidence and second in cancer mortality based on data from 2013.

CRC is one of the most preventable cancers because its development in general follows an adenoma-carcinoma sequence. Adenomas are considered precursor lesions for CRC.

While early detection and removal of colorectal adenoma by screening colonoscopy with polypectomy reduce CRC incidence and mortality, interval cancers (cancers that develop after a colonoscopy and before the next scheduled colonoscopy) may still occur and were reported to account for up to 10.5% of CRC. The protective effect of colonoscopy against cancer in the right colon has not been consistently demonstrated. Interval CRC has been associated with proximal colon location, small lesion, flat lesion, missed lesion, inadequate examination, incomplete resection of lesion, tumor biology, and low adenoma detection rate (ADR).

High ADR (eg, ≥ 20%) has been associated with a reduced risk of interval CRC. Methods that can improve polyp detection in the right colon such as retroflexed examination of the right colon, second forward view examination of the right colon, use of colonic fold flattening device, colonoscope with an increased field of view may potentially reduce the risk of interval CRC, but data is still limited. Performance of a second forward view (SFV) examination of the right colon may be the easiest and safest from a practical standpoint when compared to other options (eg, additional training is often needed for retroflexed examination of the right colon since there may be a potentially higher risk of perforation in endoscopists not familiar with the technique, additional equipment is needed when using a colonic fold flattening device, or a colonoscope with an increased field of view).

Our current study aims to determine whether a routine SFV examination in the right colon can lead to an increase in adenoma / polyp detection when compared to conventional withdrawal examination in the right colon in both male and female patients undergoing screening and surveillance colonoscopies.

Study Overview

• Status: Completed
• Conditions: Colorectal Cancer; Colonic Polyp
• Intervention / Treatment: Diagnostic test: Second forward view (SFV) examination of the right colon

Detailed Description

It is estimated that there are about 1.4 million patients with colorectal cancer (CRC) worldwide, with a rising trend in CRC incidence in many Asian Pacific countries. In Hong Kong, colorectal cancer ranks first in cancer incidence and second in cancer mortality based on data from 2013.

CRC is one of the most preventable cancers because its development in general follows an adenoma-carcinoma sequence. Adenomas are considered precursor lesions for CRC.

While early detection and removal of colorectal adenoma by screening colonoscopy with polypectomy reduce CRC incidence and mortality, interval cancers (cancers that develop after a colonoscopy and before the next scheduled colonoscopy) may still occur and were reported to account for up to 10.5% of CRC. The protective effect of colonoscopy against cancer in the right colon has not been consistently demonstrated. Interval CRC has been associated with proximal colon location, small lesion, flat lesion, missed lesion, inadequate examination, incomplete resection of lesion, tumor biology, and low adenoma detection rate (ADR).

High ADR (eg, ≥ 20%) has been associated with a reduced risk of interval CRC. Methods that can improve polyp detection in the right colon such as retroflexed examination of the right colon, second forward view examination of the right colon, use of colonic fold flattening device, colonoscope with an increased field of view may potentially reduce the risk of interval CRC, but data is still limited. Performance of a second forward view (SFV) examination of the right colon may be the easiest and safest from a practical standpoint when compared to other options (eg, additional training is often needed for retroflexed examination of the right colon since there may be a potentially higher risk of perforation in endoscopists not familiar with the technique, additional equipment is needed when using a colonic fold flattening device, or a colonoscope with an increased field of view).

Our current study aims to determine whether a routine SFV examination in the right colon can lead to an increase in adenoma / polyp detection when compared to conventional withdrawal examination in the right colon in both male and female patients undergoing screening and surveillance colonoscopies.

• Study Type: Interventional
• Enrollment (Actual): 1011
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Hong Kong
  • Hong Kong, Hong Kong
    • Prince of Wales Hospital
  • Hong Kong, Hong Kong
    • Alice Ho Miu Ling Nethersole Hospital
  • New Territories
    • Sha Tin, New Territories, Hong Kong
      • Prince of Wales Hospital, The Chinese University of Hong Kong

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria

• Patients undergoing colonoscopy for CRC screening or polyp surveillance
• Age 50 - 75 years
• Written informed consent available

Exclusion Criteria

• Contraindications for endoscopy due to comorbidities
• Unable to provide written informed consent
• Personal history of prior resection of any portion of the colon, familial polyposis syndrome, inflammatory bowel disease
• Patients with incomplete colonoscopy (i.e, inability to achieve cecal intubation), a Boston Bowel Preparation Scale (BBPS) score of 0 in either right colon, transverse colon, or left colon at the time of colonoscopy
• Known history of coagulopathy and thrombocytopenia
• Pregnant patients

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Second forward view exam; During withdrawal, the colonoscope will be advanced to the cecum again when hepatic flexure was reached the first time, where a second forward view (SFV) examination of the right colon will be performed.	Diagnostic test: Second forward view (SFV) examination of the right colon; The colonoscope will be advanced to the cecum again when hepatic flexure was reached the first time, where a second forward view (SFV) examination of the right colon will be performed
No Intervention: Conventional withdrawal exam; No intervention additional to the conventional withdrawal examination during withdrawal

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Per-patient ADR in the right colon in each group.	For the SFV group, it is defined as the number of patients with at least 1 adenoma identified in the right colon on either the first or second examination of the right colon divided by the total number of patients in the SFV group. Thus, if a patient has at least 1 adenoma detected on both the first examination and the second examination of the right colon, then this patient will be counted once only. For the conventional group, it is defined as the number of patients with at least 1 adenoma identified in the right colon on the conventional withdrawal examination of the right colon divided by the total number of patients in the conventional withdrawal group.	24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Increase in per-patient ADR in the right colon in the SFV group.	It is defined as the difference between the new ADR in the right colon after the first examination and SFV (again, if a patient has at least 1 adenoma detected on both the first examination and the second examination of the right colon, then this patient will be counted once only) and the ADR in the right colon after the first examination.	24 months
Overall ADR for the entire colon in each group.	For the SFV group, it is defined as the number of patients with at least 1 adenoma identified on either the second examination of the right colon or on the first examination of the right + examination from hepatic flexure to rectum, divided by the total number of patients in the SFV group. Thus, if a patient has at least 1 adenoma detected on both the first examination and the second examination of the right colon, then this patient will be counted once only. For the conventional group, it is defined as the number of patients with at least 1 adenoma identified in the whole colon on the conventional withdrawal examination divided by the total number of patients in the conventional withdrawal group.	24 months
The number of patients with at least 1 additional adenoma detected in right colon in the SFV group	For the SFV group, this is the additional adenoma yield on 2nd forward view exam of the right colon	24 months
Adverse events during colonoscopy and up to 30 days post colonoscopy	Adverse event rate in SFV group and conventional group	24 months
Total number of adenomas found on the first and second examinations of the right colon in the SFV group, and that on the examination of the right colon in the conventional group	This represents the absolute number of adenomas found on the first and second examinations of the right colon in the SFV group, and that on the examination of the right colon in the conventional group	24 months
Total number of polyps found on the first and second examinations of the right colon in the SFV group, and that on the examination of the right colon in the conventional group	This represents the absolute number of polyps found on the first and second examinations of the right colon in the SFV group, and that on the examination of the right colon in the conventional group	24 months

Collaborators and Investigators

• Sponsor: Chinese University of Hong Kong
• Investigators: Principal Investigator: Raymond Tang, MD, Institute of Digestive Disease, The Chinese University of Hong Kong

Publications and helpful links

General Publications

• Tang RSY, Lee JWJ, Chang LC, Ong DEH, Chiu HM, Matsuda T, Kim HS, Sekiguchi M, Leong RW, Ho AMY, Lam TYT, Tse YK, Lin L, Yeoh KG, Lau JYW, Sung JJY; Asia Pacific Working Group on Colorectal Cancer Screening. Two vs One Forward View Examination of Right Colon on Adenoma Detection: An International Multicenter Randomized Trial. Clin Gastroenterol Hepatol. 2022 Feb;20(2):372-380.e2. doi: 10.1016/j.cgh.2020.10.014. Epub 2020 Oct 14.

Study record dates

Study Major Dates

• Study Start (Actual): November 16, 2016
• Primary Completion (Actual): December 31, 2020
• Study Completion (Actual): December 31, 2020

Study Registration Dates

• First Submitted: April 16, 2017
• First Submitted That Met QC Criteria: April 19, 2017
• First Posted (Actual): April 20, 2017

Study Record Updates

• Last Update Posted (Actual): February 1, 2021
• Last Update Submitted That Met QC Criteria: January 27, 2021
• Last Verified: January 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathological Conditions, Anatomical; Intestinal Polyps; Polyps; Colonic Polyps
• Other Study ID Numbers: SFVRC Study

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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