However, it

is rather difficult to accurately diagnose a sm-slight invasive cancer preoperatively, so in clinical practice, the point is to diagnose CAL-101 chemical structure between mucosal/sm-slight cancer and massive submucosal invasive cancer (invasion of 1000 µm or more, termed sm-deep). At present, the current modalities to estimate tumor depth include ordinary colonoscopy, chromoendoscopy, magnification endoscopy (ME), endoscopic ultrasonography (EUS). In this issue of the Journal of Gastroenterology and Hepatology, Ikehara et al. report the diagnostic accuracy of seven characteristic endoscopic factors and pit pattern classification that suggest sm-deep invasion according to macroscopic type of tumor.3 Endoscopic diagnosis is potentially susceptible to the endoscopist’s skill, making it rather difficult to establish an objective characteristic for diagnosis except for the size of the tumor. Size, however, does not determine the depth of invasion of early colorectal cancer.4 In their study, to minimize such observer-related bias, endoscopic Vemurafenib diagnoses were made on agreement by three expert colonoscopists and compared to histological diagnoses. Although the seven characteristic endoscopic factors

are known as findings related to submucosal invasion among experienced colonoscopists,5 there has been no report that objectively assessed its diagnostic accuracy. These factors could be observed by thorough rinsing of the lesion and careful observation with changing the air-flow rate during screening or ordinary colonoscopy,

MCE公司 with or without chromoendoscopy. When a particular lesion included four or more such endoscopic factors, overall diagnostic accuracy was highest for the pedunculated type (86%). As for both the sessile and superficial types, it was as high as 81% and 80%, respectively, when two or more of the endoscopic factors were observed. It is highly important that a diagnosis made by ordinary colonoscopic findings could achieve such good results without using extra devices. Pit pattern classification using ME has been reported to be effective for the diagnosis of neoplastic and non-neoplastic lesions, and for diagnosing the depth of early CRC.6 In the study of Ikehara et al. overall accuracy for differentiating mucosal/sm-slight cancer from sm-deep cancer was 84% in the pedunculated type, 89% in the sessile type and 93% in the superficial type. The diagnostic accuracy of the pit pattern was lower for pedunculated type lesions than for the other two macroscopic subtypes. This trend could be speculated from the fact that many previous studies report the efficacy of pit pattern classification in superficial flat and depressed lesions.6,7 Concerning pit pattern classification, there is a point to notice that an accurate assessment of a pit pattern cannot always be achieved. As in the study of Ikehara et al. 14 % of the lesions were excluded from the study because of irremovable mucus or because the pictures were out of focus.