[Characteristics of patients with familial adenomatous polyposis in Spain. First results of the Spanish Registry of Familial Adenomatous Polyposis]

Abstract

Background and objectives: Familial adenomatous polyposis is an inherited disorder characterized by the presence of multiple colorectal adenomas (more than 100 in the classic form and between 10 and 100 in the attenuated one), with a high risk of colorectal cancer development. To improve the diagnostic and therapeutic management of these patients, the Spanish Registry of Familial Adenomatous Polyposis was created in 2007.We aimed to evaluate the clinicopathological characteristics of patients with familial adenomatous polyposis in Spain.

Patients and methods: All patients included in the Registry during one year were evaluated with respect to their demographic, clinical, pathological, and genetic characteristics.

Results: 243 patients of 156 unrelated families from 15 Spanish centers were included. One hundred thirty patients were male, and the mean age at diagnosis was 40 years. According to the clinical presentation, 127 corresponded to the classic form and 116 to the attenuated one. Colorectal adenoma with high-grade dysplasia was identified in 67 (28%) patients, and colorectal cancer in 42 (17%). Extracolonic manifestations were: duodenal involvement (n=46), gastric involvement (n=44), desmoid tumors (n=24), thyroid cancer (n=8), osteomas (n=6) and brain tumor (n=1). APC and/or MYH gene testing was performed in 140 (90%) families, detecting the causative mutation in 75 (54%) of them (70 in the APC gene and 5 in the MYH gene).

Conclusions: During its first year of operability, a large number of patients and families were included in the Registry. The reduced prevalence of colorectal cancer as well as the large proportion of families submitted to gene testing demonstrated a high-quality clinical practice in Spain.