Published online Nov 14, 2018. doi: 10.3748/wjg.v24.i42.4809
Peer-review started: July 4, 2018
First decision: August 25, 2018
Revised: October 19, 2018
Accepted: October 26, 2018
Article in press: October 26, 2018
Published online: November 14, 2018
To determine the usefulness of assigning narrow-band imaging (NBI) scores for predicting tumor grade and invasion depth in colorectal tumors.
A total of 161 colorectal lesions were analyzed from 138 patients who underwent endoscopic or surgical resection after conventional colonoscopy and magnifying endoscopy with NBI. The relationships between the surface and vascular patterns of the lesions, as visualized with NBI, and the tumor grade and depth of submucosa (SM) invasion were determined histopathologically. Scores were assigned to distinct features of the surface microstructures of tubular and papillary-type lesions. Using a multivariate analysis, a model was developed for predicting the tumor grade and depth of invasion based on NBI-finding scores.
NBI findings that correlated with a high tumor grade were associated with the “regular/irregular” (P < 0.0001) surface patterns and the “avascular area” pattern (P = 0.0600). The vascular patterns of “disrupted vessels” (P = 0.0714) and “thick vessels” (P = 0.0133) but none of the surface patterns were associated with a depth of invasion of ≥ 1000 μm. In our model, a total NBI-finding score ≥ 1 was indicative of a high tumor grade (sensitivity: 0.97; specificity: 0.24), and a total NBI-finding score ≥ 9 (sensitivity: 0.56; specificity: 1.0) was predictive of a SM invasion depth ≥ 1000 μm. Scores less than these cutoff values signified adenomas and a SM invasion depth < 1000 μm, respectively. Associations were also noted between selected NBI findings and tumor tissue architecture and histopathology.
Our multivariate statistical model for predicting tumor grades and invasion depths from NBI-finding scores may help standardize the diagnosis of colorectal lesions and inform therapeutic strategies.
Core tip: While magnifying endoscopy with narrow-band imaging (NBI) has been integrated into diagnostic histopathology, universal standardized criteria for differentiating non-neoplastic lesions, benign adenomas, and malignant neoplasms using NBI are urgently needed. We propose a multivariate statistical model for predicting the tumor grade and invasion depth from NBI finding scores. A total NBI-finding score ≥ 1 is indicative of a high tumor grade (sensitivity: 0.97; specificity: 0.24), while a score ≥ 9 (sensitivity: 0.56; specificity: 1.0) is predictive of a submucosa invasion depth ≥ 1000 μm. Our model may help to standardize the diagnosis of colorectal lesions and inform therapeutic strategies.