Validity of conventional endoscopy using non-extension sign for optical diagnosis of colorectal deep submucosal invasive cancer

摘要

Background and study aims  The non-extension sign relates to a localized increase in thickness and rigidity due to deep submucosal invasive (SM-d: depth of 1000 μm or more) cancer. The present study aimed to evaluate the efficacy of the non-extension sign in assessing the optical diagnosis of colorectal SM-d cancer.