Cell proliferation of the duodenal mucosa in patients affected by familial adenomatous polyposis

BACKGROUND & AIMS: Patients affected by familial adenomatous polyposis (FAP) are at increased risk of developing duodenal adenomas. In this study, cell proliferation of duodenal mucosa was analyzed to detect kinetic abnormalities related to cancer risk. METHODS: Duodenal biopsy specimens were collected in three groups of patients: group A, 9 hospital controls; group B, 14 patients with FAP without duodenal adenomas; and group C, 6 patients with FAP and duodenal adenomas. Proliferative cell nuclear antigen was assessed through immunohistochemistry. The main labeling parameters were (1) overall labeling index (LI) and (2) LI in the upper 40% of the crypts. RESULTS: Overall LI in groups B and C was higher than in group A (both P < 0.01). LI in group C was also significantly higher than in group B (P < 0.01). Similarly, the upper 40% LI was higher in groups B and C than in group A (both P < 0.01). This value was higher in group C than in group B (P < 0.05). CONCLUSIONS: These data suggest the presence of cell kinetics abnormalities in FAP and the existence of two subgroups of patients with FAP at different risks of duodenal neoplasia. These abnormalities could be used as an intermediate biomarker for chemoprevention studies of duodenal cancer in FAP.