Advanced Techniques in Colonoscopy in Inherited Cancer Conditions

Colorectal cancer (CRC) is the third most incident cancer and is the second most common cause of cancer mortality globally. Although mostly CRCs are sporadic, a familial aggregation is observed in 10-30% of CRCs and, 5-10% are caused by known inherited pathogenic variants. Among these, Lynch Syndrome is the most frequent hereditary condition, caused by germline mutations in one of the DNA mismatch repair genes, namely, MLH1, MSH2, MSH6, and PMS2. Serrated polyposis syndrome has an uncertain inherited transmission but it is considered a major risk factor for CRC. Familial adenomatous polyposis is an autosomal dominant syndrome characterized by a pathogenic variant in APC gene and a 100% of prevalence for CRC. Early detection of both CRCs and precancerous lesions by means of lower GI endoscopy plays a crucial role in hereditary colorectal syndromes, reducing CRC-related incidence and mortality. In this context, a colonoscopy of high quality, based on specific indicators, is the key for a proper endoscopic surveillance. In the last few years, advances in imaging techniques allowed better detection and characterization of colorectal lesions aiding endoscopists in improving the quality of colonoscopy. High-definition endoscopes, dye-based and virtual (NBI, FICE, I-SCAN) chromoendoscopy, autofluorescence imaging, and device-assisted colonoscopy have been increasingly employed in endoscopic clinical practice. This chapter aims to give a technical overview regarding the role of advanced techniques in inherited colorectal syndromes, focusing on Lynch syndrome, Serrated polyposis syndrome, and Familial adenomatous polyposis.