Influence of demographic parameters on rectal epithelial proliferation.

Measurement of rectal epithelial proliferation is now being used as a biomarker for assessing risk for colorectal cancer and response within dietary intervention studies. We examined the possible confounding effects of demographic parameters on the proliferation of 52 healthy middle-aged volunteers without known risk factors for colorectal cancer. No significant effects on proliferation of age, sex or ethnic grouping were found other than marked urban-rural differences amongst men. We hypothesise that these could be explained by differences in dietary habits and their deleterious effects in the older male population. Careful matching of controls are probably needed in order to demonstrate the minor changes in mucosal proliferation that could reflect risk for neoplasia. Further human studies are needed to examine the effects of diet and extremes of age on proliferation.