Interobserver Agreement among Experts in Determining the Depth of Invasion of Early Colorectal Carcinoma

Ji, Jeong Seon; Choi, Hwang; Choi, Kyu Yong; Lee, Bo In; Kim, Kyoung Mee; Kim, Byung Wook; Cho, Se Hyun; Son, Seong Hyun; Chae, Hiun Suk; Chung, In Sik

Abstract

BACKGROUND/AIMS
Discrimination between mucosal and submucosal colorectal cancer is important because of different therapeutic plan. Although many characteristic endoscopic findings suggesting submucosal cancer were demonstrated, there are few reports about diagnostic accuracy and interobserver agreement among experienced endoscopists. So we studied about diagnostic accuracy and interobserver agreement about the diagnosis of submucosal invasive colorectal carcinoma by endoscopic findings.
METHODS
Fifty patients (58% male, mean age 64 years) diagnosed pathologically as early colorectal carcinoma after polypectomy and operation were randomly selected. Fifteen cases were submucosal invasive colorectal carcinoma. Three experienced endoscopists (A, B and C) blinded to the patient's data reviewed photographs.
RESULTS
Diagnostic accuracy of submucosal cancer by A, B and C were 82%, 74% and 78%, respectively. A to B and A to C showed moderate agreement in the diagnosis of submucosal invasion (kappa=0.504 and kappa=0.649). However, agreement power between B and C was somewhat weak (kappa=0.298). Among endoscopic findings, three experts strongly agreed on the features of white spots, hemorrhage and exudate (kappa=0;73, kappa=0.649 and kappa=0.641, respectively).
CONCLUSIONS
Interobserver agreement in the diagnosis of submucosal colorectal carcinoma was moderate among three experts. More meticulous effort to improve interobserver agreement and accuracy in the diag- nosis of submucosal invasive colorectal carcinoma is mandatory.