Outcome of familial adenomatous polyposis: a retrospective study.

Background: Familial adenomatous polyposis (FAP) is characterized by the presence of numerous colorectal adenomatous polyps that progress to colorectal cancer if left untreated. Following colorectal cancer, periampullary cancer and aggressive desmoid tumor are also the common causes of death. The purpose of the present study was to describe the clinical course of FAP patients.

Material And Method: The authors conducted a retrospective study of 31 FAP patients who were treated at King Chulalongkorn Memorial Hospital (KCMH) between March 2000 and March 2006. Demographic data, family history, symptoms, extracolonic manifestations, operative procedures, pathologic findings, and postoperative results were collected.

Results: Two patients were excludedfrom the present study. The average age of the 29 patients was 33.48 years with the sex ratio (male/female) of 0.93. Seventeen of the 29 patients (58.6%) had a family history of FAP Sixteen of 29 patients were discovered with colorectal cancer with a mean age of34.56 years. Mucous bloody stool was the most common presenting symptom and most of the patients with this symptom (11/13) already had colorectal cancer Gastroduodenal polyps and desmoid tumor were common extracolonic manifestations. The most common operative procedure was restorative proctocolectomy with ileal J pouch (RPC). Wound infection and gut obstruction were the frequent complications. Functional outcomes of patients with RPC were good. The mean age ofpatients with colon cancer was older than the mean age ofpatients without colon cancer However, there was no significant difference between the two groups. The sex ratio and family history of FAP were not statistically different. No significant differences were found in surgical procedures and postoperative complications. On the follow up period, two patients in the later group died of desmoid tumor and pancreatic cancer while seven patients in the former group died of metastatic colon cancer and one with desmoid tumor

Conclusion: The proportion ofpatients who were discovered with colorectal cancer in the present study was high with young age onset of cancer Moreover, patients in this group had poorer outcome compared to the group of patients without colorectal cancer; of which, metastatic colorectal cancer was the major cause of death. This result may be due to aggressiveness and advanced stage of disease at the first diagnosis.