Published online Mar 14, 2018. doi: 10.3748/wjg.v24.i10.1167
Peer-review started: January 9, 2018
First decision: February 5, 2018
Revised: February 18, 2018
Accepted: February 15, 2018
Article in press: February 15, 2018
Published online: March 14, 2018
Patients with inflammatory bowel disease (IBD) colitis are known to have an increased risk of colorectal cancer compared to that of non-colitic patients. This is thought to progress along the inflammation-dysplasia-carcinoma pathway. Many studies and meta-analyses have been performed for lesion detection in IBD but few studies have looked into in-vivo lesion characterization. This is the first meta-analysis on lesion characterization in colonic IBD.
Characterization of colonic lesions in IBD maybe more challenging because they tend to be flatter and their pit-pattern maybe obscured by inflammation. Some patients also have numerous pseudopolyps throughout the colon, making polypectomy impractical, time-consuming, costly and potentially associated with increased risk. If we are able to characterize these lesions with a high accuracy without needing to perform polypectomy, we could potentially circumvent these problems.
Our objective was to perform the first systematic review and meta-analysis for the diagnostic accuracy of optical imaging techniques for in-vivo lesion characterization in colonic IBD.
We conducted a review of the current literature and included studies which characterized lesions in-vivo into neoplastic and non-neoplastic, using histology as the gold standard. Data was pooled for each technology using a bivariate meta-analysis with a random effects model to account for study differences. Sensitivities, specificities, positive and negative likelihood ratios, diagnostic odds ratio, and area under summary receiver-operator characteristic curve, were calculated for each technology type.
Confocal laser endomicroscopy (CLE) had the greatest accuracy for differentiating neoplastic from non-neoplastic lesions in-vivo. Magnification and virtual chromoendoscopy (VCE) performed well, whilst dye-based chromoendoscopy (DBC) had suboptimal accuracy.
CLE is highly accurate at in-vivo lesion characterization but studies are within experienced centres with mainly single expert users limiting its generalizability.
Future studies should look at newer generation virtual chromoendoscopic technology [narrow band imaging (NBI), i-scan, fujinon intelligence chromoendoscopy (FICE)] for lesion characterization. A standardised mucosal lesion classification system specific for lesions in IBD colitis accounting for the technology being used should be explored.