Clinicopathological risk factors of early carcinoma in colorectal neoplasias according to Japanese and Western criteria.

Abstract There are discrepancies in the classification of early carcinoma in colorectal neoplasia between Japanese and Western criteria. However, no studies have investigated the clinicopathological risk factors associated with early carcinoma according to these criteria. We compared the clinicopathological risk factors of early carcinoma with those of dysplasia, and used multivariate analysis to elucidate the independent risk factors associated with early carcinoma. Lesions with severe cytologic or architectural changes confined to the mucosa are classified as carcinoma in Japanese criteria and as high grade dysplasia (HGD) in Western criteria. Pathologically, 625 total patients were diagnosed with low grade dysplasia (n=321), HGD (n=244), intramucosal carcinoma (n=35) or submucosal carcinoma (n=25). In multivariate analysis, age, large lesion size, and non-polypoid appearance were associated with carcinoma in Japanese criteria; however, only large lesion size was associated with carcinoma in Western criteria. The clinicopathological characteristics of intramucosal carcinoma were similar to those of submucosal carcinoma rather than HGD. The clinicopathological characteristics for early carcinoma were not identical between Japanese and Western criteria. Japanese criteria classifying intramucosal carcinoma as carcinoma rather than HGD may be supported by our findings.