EFFECT OF LONG-TERM PLACEBO-CONTROLLED CALCIUM SUPPLEMENTATION ON SIGMOIDAL CELL-PROLIFERATION IN PATIENTS WITH SPORADIC ADENOMATOUS POLYPS

A longterm, double blind intervention trial was undertaken in patients with sporadic adenoma treated by polypectomy to investigate the putat ive role of calcium as a protective factor in colon carcinogenesis. Th e aim of the study was to assess the effect of a daily dietary supplem entation of 2 g calcium over nine months on cell proliferation measure d as proliferation index in colonic mucosa. A total of 48 patients wer e entered into the study of which 30 were fully compliant. After inter vention proliferation index % (mean (SEM) in colonic epithelium was de creased in both the calcium (13.5 (1.5) to 11.4 (1.2)) and the placebo group (13.7 (0.9) to 10.8 (1.1)). The difference in the change betwee n the two groups was not significant (p=0.7). Changes in proliferation index % of crypt compartments were also not significantly different b etween the two groups. A significantly positive correlation between so luble calcium in faeces and the total proliferation index % in colonic epithelium at baseline and after intervention (r=0.54, p<0.01, r=0.50 , p<0.01 respectively) suggests that an increase of free luminal calci um alone is insufficient for inhibition of cellular proliferation.