Chemoprevention of colon cancer: metaanalysis & systematic review of preclinical studies in rats & mice
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Meta-Analysis of Chemoprevention Studies with Calcium
in Carcinogen-Initiated Rats and in Min Mice.

Figures from Rat Data Tables

Calcium Chemoprevention Colon Tumor Incidence in Rats. all studies. Funnel plot Calcium Chemoprevention Colon Tumor Incidence in Rats. Calcium Lactate Chemoprevention Colon Tumor Incidence in Rats. Calcium All but Lactate Chemoprevention in Rats. Calcium Chemoprevention in High Fat diets, in Rats. Calcium Chemoprevention in Low Fat diets, in Rats

Identical figures below as above, but "Text links" instead of "Icon links"

An Explanation of Data Presented Above

Calcium effect in carcinogen-injected rats. The meta-analysis of 17 publications including 1732 rats showed that calcium reduces colon tumour incidence in rats: RR= 0.91 (p=0.03) [Table], with similar RR with Random model (0.92, p=0.06) [Figure]. The hypothesis that calcium specifically reduces high-fat diet promotion was tested by analysing separately studies with high fat (>20% fat, w/w) and low fat diets (< 6%), but both subsets yielded similar RRs 0.93 & 0.92, and p values (see figures: High Fat & Low Fat). Also, we tested the hypothesis that some calcium salts were more protective than others. This was indeed the case: calcium lactate was protective in rats (RR=0.7, p=0.02, Figure), but phosphate, carbonate and gluconate afforded no protection (RR=1, Figure).
Calcium effect in mutated mice. Small intestinal polyp yield increases by +9 and +21% when dietary calcium doubles (79 mice: 2 lines on top of [Table]. Calcium did not reduce the number of colonic polyps either . In contrast, mice fed the high-calcium AIN76 diet had fewer polyps than mice fed the low-calcium Western diet designed by Newmark . This polyp reduction to 37% of control value (weighted mean, p<0.001) cannot however be attributed to calcium alone, since diets also differed for phosphate, fat, and vitamin D content (6 lines at bottom of [Table]).
Text extracted from the article: "Corpet D.E. & Pierre F., 2005, European Journal of Cancer, How good are Rodent Models of Carcinogenesis in Predicting Efficacy in Humans? Systematic Review and Meta-Analysis of Colon Tumour Chemoprevention in Rats, Mice and Men. in the press." Fetch the [preprint] (.pdf)

Abbreviations /Data Tables

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DE Corpet & F Pierre, 2005, European J. Cancer
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