RT Book, Section A1 Cruz-Correa, Marcia A1 Ballester, Veroushka A2 Llor, Xavier A2 Hofstatter, Erin Wysong SR Print(0) ID 1182365513 T1 Gastrointestinal Polyposis Syndromes T2 Cancer Genetics: A Clinical Approach YR 2022 FD 2022 PB McGraw Hill PP New York, NY SN 9781260440270 LK hemonc.mhmedical.com/content.aspx?aid=1182365513 RD 2024/03/28 AB Gastrointestinal (GI) polyposis syndromes are a group of conditions that are associated with an increased lifetime risk of colorectal adenocarcinoma and extraintestinal malignancies. The polyposis syndromes have traditionally been categorized according to polyp histology (adenomatous, hamartomatous, and serrated) and clinical phenotype. Criteria to be considered in differentiating the various polyposis conditions include polyp distribution throughout the GI tract, polyp number, the presence of extraintestinal manifestations or malignancy, and family history. Identification of relevant causative genes has improved our understanding of specific polyposis conditions, including phenotypic characteristics and associated cancer risks. The most common feature for when to consider a polyposis diagnosis and germline genetic testing is the finding of 10 or more colonic polyps, polyposis in other parts of the GI tract, and polyps in young individuals with a family history of a polyposis diagnosis. The clinical importance of these syndromes relates to their inheritance. Mutation-specific genetic testing offers the opportunity to test family members for the pathogenic mutation found in an index case, allowing a more personalized approach for cancer prevention with tailored screening and surveillance interventions.