Efficacy of the Invasive/Non-invasive Pattern by Magnifying Chromoendoscopy to Estimate the Depth of Invasion of Early Colorectal Neoplasms

OBJECTIVE: During colonoscopy, estimation of the depth of invasion in early colorectal lesions is crucial for an adequate therapeutic management and for such task, magnifying chromoendoscopy (MCE) has been proposed as the best in vivo method. However, validation in large-scale studies is lacking. The aim of this prospective study was to clarify the effectiveness of MCE in the diagnosis of the depth of invasion of early colorectal neoplasms in a large series. METHODS: A total of 4,215 neoplastic lesions were evaluated using MCE from October 1998 to September 2005 at the National Cancer Center Hospital, Tokyo, Japan. Lesions were prospectively classified according to the clinical classification of the pit pattern: invasive pattern or non-invasive pattern. All lesions were histopathologically evaluated. RESULTS: There were 3,371 adenomas, 612 intramucosal cancers (m-ca), 232 submucosal cancers (sm-ca): 52 sm superficial (sm1) and 180 sm deep cancers (sm 2-3). Among lesions diagnosed as invasive pattern, 154 out of 178 (86.5%) were sm2-3, while among lesions diagnosed as non-invasive pattern, 4,011 out of 4,037 (99.4%) were adenomas, m-ca, or sm1. Sensitivity, specificity and diagnostic accuracy of the invasive pattern to differentiate m-ca or sm1 (<1000 mu m) from sm2-3 (>= 1000 mu m) were 85.6%, 99.4%, and 98.8%, respectively. CONCLUSION: The determination of invasive or non-invasive pattern by MCE is a highly effective in vivo method to predict the depth of invasion of colorectal neoplasms.