Clinical trial NCT03121495: Study on Second Forward View Examination in the Right Colon
Official title: 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)
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Colonic Polyp
Colorectal Cancer
Lead sponsor: Chinese University of Hong Kong
Sponsor class: OTHER
First posted: 2017-04-20
Enrollment: 1011
Sex: ALL
Minimum age (years): 50
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: DIAGNOSTIC

Brief summary: 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.

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.

Eligibility criteria: 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

Primary outcomes:
measure: Per-patient ADR in the right colon in each group.
timeFrame: 24 months
Secondary outcomes:
measure: Increase in per-patient ADR in the right colon in the SFV group.
timeFrame: 24 months
measure: Overall ADR for the entire colon in each group.
timeFrame: 24 months
measure: The number of patients with at least 1 additional adenoma detected in right colon in the SFV group
timeFrame: 24 months
measure: Adverse events during colonoscopy and up to 30 days post colonoscopy
timeFrame: 24 months
measure: 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
timeFrame: 24 months
measure: 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
timeFrame: 24 months
Other outcomes:
Locations:
city: Sha Tin
country: Hong Kong
facility: Prince of Wales Hospital, The Chinese University of Hong Kong
state: New Territories
city: Hong Kong
country: Hong Kong
facility: Alice Ho Miu Ling Nethersole Hospital
city: Hong Kong
country: Hong Kong
facility: Prince of Wales Hospital
Study officials:
affiliation: Institute of Digestive Disease, The Chinese University of Hong Kong
name: Raymond Tang, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.