Prospective Study of Non-Lifting Sign As a Diagnostic Tool for Colorectal Neoplastic Lesions

Abstract

Background: In Japan, SM1 (less than 1 mm distance from the muscularis mucosae to the deepest point of invasion) colorectal cancers without lymphovascular involvement or a poorly differentiated component are thought to be resectable by endoscopy, similarly to adenoma and intramucosal cancer. To determine the appropriate treatment for colorectal neoplastic lesions, it is necessary to estimate whether or not the depth of invasion from the muscularis mucosae is less than 1 mm. Magnifying colonoscopy and endoscopic ultrasound are reported to be helpful for such endoscopic estimation, although only experts can use these techniques adequately. Aim: To assess, prospectively, the feasibility of the non-lifting sign as a diagnostic tool in comparison with endoscopic diagnosis. Patients and methods: This was a prospective trial conducted at 5 medical centers in Japan. During the period between January and November 2004, a total of 271 colorectal neoplastic lesions in 239 patients were evaluated. The location, size, and macroscopic type of the lesion, endoscopic assessment of the depth of invasion, and presence or absence of the non-lifting sign were recorded for comparison. Results: The overall accuracy of the non-lifting sign was 94.8% (257/271), and the sensitivity and specificity were 61.5% (16/26) and 98.4% (241/245), respectively. On the other hand, the overall accuracy, sensitivity and specificity of endoscopic diagnosis were 97.4% (264/271), 84.6% (22/26) and 98.8% (242/245), respectively. Although the overall accuracy and specificity of the non-lifting sign were similar to those of endoscopic diagnosis, the sensitivity of the former was significantly lower than that of the latter (p = 0.031). Conclusion: Because of its significantly lower sensitivity, the non-lifting sign is unable to take the place of endoscopic diagnosis.