The risk of gastrointestinal carcinoma in familial juvenile polyposis.

BACKGROUND: Familial juvenile polyposis (JP) is an autosomal dominant condition in which affected individuals develop upper or lower gastrointestinal (GI) juvenile polyps, or both, and have a predisposition to cancer of the gastrointestinal tract. The risk of GI cancer has not been well defined because of the small number of these families and the lack of follow-up. The objective of this study was to determine the prevalence and age at diagnosis of GI polyposis and cancer in a large JP kindred.

METHODS: Medical records were reviewed, patients were interviewed, and histories were taken. Pathology reports and slides were reviewed by our pathologists. A database was created for analysis of clinical and pathologic factors.

RESULTS: This kindred contains 117 members, 29 of whom have had upper or lower GI polyps or cancer, or both. All those affected have had colonic juvenile polyps or cancer, except for two who died of advanced gastric cancer and never had colonic evaluation. Nine individuals have had both upper and lower GI polyps or cancer. Sixteen of 29 (55%) affected patients have developed gastrointestinal cancer. Eleven (38%) have had colon cancer, and six (21%) have had upper GI cancers.

CONCLUSIONS: The risk of gastrointestinal malignancy in affected members of this JP kindred exceeds 50%. The high risk of GI cancer warrants frequent endoscopic screening of both affected and at-risk family members. Screening will soon be facilitated by presymptomatic genetic testing for the identification of gene carriers.