Rectal cell proliferation and colon cancer risk in patients with hypergastrinaemia

Backgrounds - The influence of gastrin on the colonic mucosa is still uncertain. Some authors have suggested a stimulating effect on the growth of normal and malignant colonic epithelium, while others have shown no association between gastrin and neoplastic development. Aims - To evaluate the effect of gastrin on colorectal cell proliferation, patients with chronic endogenous hypergastrinaemia underwent proctoscopy. Biopsy specimens were taken in order to study rectal cell kinetics. Patients and controls - Ten patients with chronic autoimmune gastritis (CAG), six patients with Zollinger-Ellison syndrome (ZES), and 16 hospital controls took part in this study. Patients with CAG and ZES had basal serum gastrin concentrations significantly higher than controls (p<0.001). Methods - Immunohistochemistry was performed on 3 μm sections of rectal biopsy specimens incubated with 5'- bromodeoxyuridine. Results - The percentage of proliferating cells in the entire crypts (overall labelling index) was similar in all the groups. However, the labelling frequency in the upper two fifths of the glands (φh value) was significantly higher in patients with CAG or ZES compared with controls (p<0.01 in bath patient groups versus controls). Conclusions - Endogenous hypergastrinaemia is associated with rectal cell proliferation defects, similar to those observed in conditions at high risk for colon cancer. The effect of the increased serum concentrations of gastrin on the colorectal mucosa after treatment with drugs inhibiting gastric acid secretion should be investigated.