ABSTRACT
This chapter examines the relationship between fecal steroids and colon cancer in animal models. It attempts to minimize any dietary variability by using a semipurified diet instead of chow. The chapter examines the effects of feeding cholic acid with and without dietary calcium in Fischer rats treated with the carcinogen N-methyl-N'-nitrosourea. It shows that colon cancer incidence may increase or decrease if the steroid/bile acid composition in the colon is altered in a controlled fashion. Bile acids and neutral sterols are the most abundant steroids found in feces. These compounds have been associated with colon tumor formation/prevention. Bile acids are involved in the absorption of fat from the intestine. An increased intake of fat leads to an increase in intestinal bile acid concentration that was associated with an increased incidence of cancer. A role for diet in cancer seems clear, and an understanding of the variables involved may enable to control the incidence of the disease.
