Management of Familial Adenomatous Polyposis

This paper reviews important aspects in the management of individuals with familial adenomatous polyposis (FAP). Newly discovered germline pathogenic variants (PVs) beyond APC are a rare cause of adenomatous polyposis. The decreasing cost of multi-gene panel testing (MGPT) has broadened the use of commercial panels to enhance the genetic diagnosis of adenomatous polyposis in families where the causative germline PV in APC is not known. We elucidate emerging risks of cancer in FAP particularly gastric cancer and provide best practices to surveillance and cancer prevention in FAP, including dual therapy chemoprevention and trials utilizing novel mechanisms. Genetic testing is indicated in individuals with ≥ 10 lifetime adenomas. FAP and MutYH-associated polyposis (MAP) will be the most common germline causes of colorectal adenomatous polyposis. In FAP, upper endoscopy is indicated for surveillance of gastric polyposis and gastric cancer in addition to duodenal polyposis. Novel agents for chemoprevention have been shown to be effective and considered for selective use in patients with FAP.