Study on Second Forward View Examination in the Right Colon
Condition: Colonic Polyp; Colorectal Cancer
MeSH terms: Polyps; Colonic Polyps
Study type: Interventional

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.
    

Intervention name(s): Second forward view (SFV) examination of the right colon
Intervention type(s): Diagnostic Test
Intervention description(s): 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
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Diagnostic