Clinical usefulness of pit patterns for detecting colonic lesions requiring surgical treatment

Background: The number of patients suffering from colorectal cancer is increasing. According to Japanese guidelines, lesions with a submucosal invasive depth >1,000 μm should be treated with radical proctocolectomy. We propose and evaluate a new clinical classification for pit patterns that uses endoscopy to assess lesion depth for determination of the appropriate therapeutic approach for early colorectal cancers and adenomas. Methods: Endoscopic images of colorectal adenomas and early cancer cases with type V _I pit pattern, resected surgically or endoscopically from April 2002 to April 2007 at Showa University Yokohama Northern Hospital, were utilized for analysis. Each image was retrospectively analyzed for (A) pit narrowness, (B) irregular pit margins, and (C) indistinct stromal staining. Sensitivity, specificity, and predictive value were evaluated as major outcomes, using pathological results as the standard. Result: In total, 186 cases were assessed. With all features considered (A, B, and C), the sensitivity, specificity, and positive and negative predictive values were 47.8%, 86.3%, 66.0%, and 74.2%, respectively. When limited to two features (A and B), these values were 75.3%, 81.2%, 70.2%, and 84.8%, respectively. Conclusion: Our results suggest that the established criteria can, to a certain degree, distinguish between high and low irregularity in colorectal lesions with V _I pit pattern indicating submucosal cancer infiltration of more or less than 1,000 μm with the clinical consequence of surgery versus endoscopic mucosal resection/endoscopic mucosal dissection.