Published online Jun 7, 2014. doi: 10.3748/wjg.v20.i21.6586
Revised: February 18, 2014
Accepted: March 7, 2014
Published online: June 7, 2014
Processing time: 195 Days and 17.2 Hours
AIM: To evaluate the depth of invasion of small, early colorectal cancers (ECCs) using conventional endoscopic features.
METHODS: From January 2005 to September 2011, colonoscopy cohort showed that a total of 72 patients with small colorectal cancers with the size less than 20 mm underwent colonoscopy at the Yonsei University College of Medicine, Seoul, South Korea. Among them, 8 patients were excluded due to incomplete medical records. Finally, a total of 64 ECCs with submucosa (SM) invasion and size less than 20 mm were included. One hundred fifty-two adenomas with size less than 20 mm were included as controls. Nine endoscopic features, including seven morphological findings (i.e., loss of lobulation, excavation, demarcated and depressed areas, stalk swelling, fullness, fold convergence, and bleeding ulcers), pit patterns, and non-lifting signs, were evaluated retrospectively. All endoscopic features were evaluated by two experienced endoscopists who have each performed over 1000 colonoscopies annually for more than five years without knowledge of the histology.
RESULTS: Among the morphological findings, the size of deep submucosal cancers was bigger than that of superficial lesions (16.9 mm vs 12.3 mm, P < 0.001). Also, demarcated depressed areas, stalk swelling, and fullness were more common in deep SM cancers than in superficial tumors (demarcated depressed areas: 52.0% vs 15.7%, P < 0.001; stalk swelling: 100% vs 4.2%, P < 0.001; fullness: 25.0% vs 0%, P = 0.001). Among deep SM cancers, 96% of polyps showed invasive pit patterns, whereas 19.4% of superficial tumors showed invasive pit patterns (P < 0.001). A positive non-lifting sign was more common in deep SM cancers (85.0% vs 28.6%, P < 0.001). Diagnostic accuracy of invasive morphology, invasive pit patterns, and non-lifting signs for deep SM cancers were 71%, 82%, and 75%, respectively.
CONCLUSION: Conventional endoscopic findings were insufficient to discriminate small, deep SM cancers from superficial SM cancers by white light, standard colonoscopy.
Core tip: This present study was designed to evaluate the depth of invasion of small, early colorectal cancers using conventional endoscopic features. This study exhibited that invasive pit patterns were a more accurate finding than morphological features or non- lifting signs to discriminate small, deep submucosa (SM) cancers from superficial SM cancers by a white light, standard colonoscopy. However, it also showed that conventional endoscopic findings, such as morphological features, non-lifting sign, and invasive pit patterns are insufficient to discriminate deep SM cancers to determine therapeutic strategy under white light standard colonoscopy.