The aim of this study was to review the clinical characteristics of gastric tumours occurring within an FAP population from the largest European polyposis registry.
Heterogeneity among and within FAP pedigrees for the age of symptom onset and the age at death from colorectal cancer was studied in a sample of 583 patients of the Italian Polyposis Registry.
The differences of these clinical findings suggested that glioma-polyposis syndrome should be classified as follows; (1) cases of Turcot's syndrome who had characteristic colonic and brain manifestations, (2) cases of FAP associated with glioma, (3) suspicious cases of glioma-polyposis, and (4) cases other than glioma-polyposis syndrome.
A comparison of the incidence rate of colon cancer in the general population with that in patients with polyposis suggests that a mutation at the FAP gene locus is not one of the rate-limiting events in colon carcinogenesis.