Clinical Analysis of 40 Patients with Familial Adenomatous Polyposis (FAP)

ABSTRACT

PURPOSE: This study was carried to find the clinical characteristics of incidence and the phenotype of familial adenomatous polyposis (FAP). METHODS: This retrospective analysis was performed on 40 patients who were diagnosed as having FAP and who underwent surgery due to FAP from June 1985 to April 2005. The operative method, extra-colonic symptoms, and number of polyps were analyzed. RESULTS: From June 1985 to April 2005, 0.65% (40 patients) of all surgically treated colon-cancer patients were diagnosed as having FAP. Seventeen patients had familial history, and 23 patients were neither aware of any familial history nor had taken any tests. The primary symptoms were hematochezia, diarrhea, mucous discharge, constipation, and abdominal pain, but 5 patients had no specific symptoms. The mean age was 38.0 years. A total colectomy with ileostomy was performed in 19 cases, a total colectomy with ileorectal anastomosis in 2 case, and a total proctocolectomy with ileal J pouch anal anastomosis in 17 cases. One case was only diagnosed as having a FAP without surgical treatment, and one cases had palliative surgery due to carcinomatosis. Thirty-five cases had more than one hundred polyps, and 5 cases had less than one hundred polyps with a higher mean age of 62.2 (50~74) years and having no familial history. Extracolonic manifestations, were congenital hypertrophy of the retinal pigment epithelium, submandibular tumor, thyroid cancer, and intraabdominal desmoid tumor. The polyps could develop in other organs, such as the stomach or the duodenum. Because they can progress to cancer, a gastroduodenoscopy needs to be done. As for result, 17 cases underwent endoscopic gastroduodenoscopy, and among them, 9 cases had multiple adenomas. CONCLUSIONS: FAP has been considered as a rare disease. Because of its association with early development of colorectal cancer, measures for early detection of the disease and for identification of other family members at risk should be performed. Furthermore, early prophylactic treatment should be undertaken to reduce the incidence of cancer in these conditions. For early detection and better outcome, clinical and radiological examination and treatment for extracolonic manifestations and extracolonic tumor (thyroid cancer, desmoid tumor, medulloblastoma, hepatoblastoma) are necessary.