The Missed Colorectal Cancer Problem

<i>Background/Aims:</i> Colonoscopy is currently regarded as the gold standard for the detection of polyps and cancers in the colon and rectum, and is the preferred method of screening for colorectal cancer in Europe and the USA. However, evidence shows that polyps and other lesions can be missed during colonoscopy due to several reasons. <i>Methods:</i> An unsystematic review of the literature concerning the issues of missed colorectal cancers and interval cancers during colonoscopy was performed and the most important articles described. <i>Results:</i> According to the literature there are various reasons for interval and/or missed colorectal cancers: incomplete bowel cleaning, incomplete colonoscopy, short withdrawal time, incomplete resection of adenomas, rapid tumor progression, sessile serrated adenomas and the examiner him- or herself. <i>Conclusion:</i> For the minimization of missed neoplasias and even cancers it is necessary to perform screening colonoscopy after an optimal bowel preparation. Furthermore, colonoscopy should be performed in an ‘optimal setting’ with adequate withdrawal time and complete resection of all polypoid lesions by experienced examiners followed by an adequate histological work-up including the knowledge about sessile serrated adenomas.