Published online May 16, 2020. doi: 10.4253/wjge.v12.i5.159
Peer-review started: February 18, 2020
First decision: March 28, 2020
Revised: April 12, 2020
Accepted: May 12, 2020
Article in press: May 12, 2020
Published online: May 16, 2020
Patients with ulcerative colitis (UC), which is a chronic inflammation of the colon and rectum, are at high risk of developing colorectal cancer (CRC), mainly if the inflammation involves the whole colon and/or lasts for a long duration. Currently, it is recommended to perform endoscopic surveillance looking for colon cancer and dysplasia in those patients after 8-10 years from the diagnosis of UC. Our study compares the best modality to use in those surveillance colonoscopies.
The main modalities used in CRC surveillance in UC are white light high definition (WL HD), WL standard definition (WL SD), chromoendoscopy (CE) HD, and narrow-band imaging (NBI) HD. There is a paucity of head-to-head comparison among these modalities to help physician in deciding what is the best option to use for early detection of dysplasia. This study is constructed to assist the clinician to choose the best yielding modality.
The main objective is to demonstrate the best modality to use in terms of detecting dysplasia and targeted biopsies. We realized that not all the modalities are equal in efficacy nor in yielding results. These objectives would be of major impact in future research and clinical practice.
The research methods (e.g., experiments, data analysis, surveys, and clinical trials) that were adopted to realize the objectives, as well as the characteristics and novelty of these research methods, should be described in detail. The methods used to reach these objectives were literature search of studies on UC dysplasia surveillance on MEDLINE, Google Scholars, Scopus, Embase, Web of Science, and Cochrane Central Register of Controlled Trials (CRC). Only prospective randomized controlled trials (RCTs) evaluating the dysplasia detection in UC that compared outcomes between two or more different endoscopic modalities were included. Data were extracted independently using a data abstraction form. Jadad score, a scale that assesses the methodological quality of a clinical trial, and Cochrane Risk of Bias Assessment Instrument were used to evaluate the methodological quality of the RCTs.
We found that for dysplasia per biopsy basis, the best modalities were NBI HD and CE HD, while on dysplasia per patient basis, WL HD and NBI HD were the highest ranked. For dysplasia numbers per patient, the three HD modalities were superior to WL SD. The striking finding was that regardless of the image enhancing modality used, HD was the most important option in detecting dysplasia. These finding could help the clinician in choosing the best yielding modality to use for CRC/dysplasia surveillance in patients with UC.
Regardless of the image enhancing modality used, HD was the most important option in detecting dysplasia in patients with UC. When HD colonoscopes are used, image enhancing modality may not be required in detecting dysplasia in patients with UC. HD was the most important option in detecting dysplasia in patients with UC. The best modality to use in surveillance colonoscopies of UC was unclear. Based on the current guidelines for colorectal cancer surveillance in patients with ulcerative colitis, we found that HD is the best option in detecting dysplasia, while white light standard definition is the most inferior option. The increased use of HD would yield the best results in both dysplasia detection rate and targeted biopsies.
Not all imaging or endoscopic modalities are equal in detecting dysplasia in UC. More data and research required to decide what is the single best modality to use in CRC/dysplasia surveillance in patients with UC. RCTs simultaneously comparing multiple modalities or a follow-up network meta-analysis when more studies become available.