| [ Summary ] |
Familial adenomatous polyposis (FAP) is an autosomal dominant inherited disorder caused by germline mutations of the APC gene. Genetic testing of the APC gene is useful for optimal treatment selection and/or surveillance in patients with FAP. Without treatment, nearly all patients with FAP develop colorectal cancer by 40 years of age. Usually, it is recommended that patients with FAP undergo prophylactic surgery in their 20s. Total proctocolectomy with ileal pouch‒anal anastomosis is the standard surgical procedure; however, total colectomy with ileorectal anastomosis is also a useful strategy in patients with FAP showing a small number of rectal adenomas. Patients with FAP are known to develop extracolonic tumors, such as duodenal adenoma/cancer and desmoid tumors. Although surgery should be considered in patients with bowel obstruction secondary to intra‒abdominal desmoid tumors, it may not be successful owing to technically difficult resection, the need for extensive intestinal resection, and/or high recurrence rates. Pancreaticoduodenectomy or pylorus‒preserving pancreaticoduodenectomy is performed for duodenal cancer; however, pancreas‒sparing duodenectomy may be performed prophylactically. Physicians should consider the genetic background of patients with FAP prior to initiation of treatment. |