Faecal neutral sterols and bile acids in patients with adenomas and large bowel cancer: an ECP case-control study

It is unclear whether neutral steroids and bile acids are involved in large bowel carcinogenesis. This study was conducted to compare the concentratio n of these faecal constituents at the different stages of the adenoma-carci noma sequence. Neutral sterols and free bile acid concentrations were deter mined from stool samples collected form patients with large bowel cancer (n = 47), large adenoma greater than or equal to 1 cm (n = 42), small adenoma (n = 24), and controls (n = 104), The distribution of tertiles between cas es and controls was analysed using odds ratio (OR), with 95% confidence int erval (CI), comparing (two-sided tests) the second tertile (OR2) and the th ird tertile (OR3) to the first one. Persistence of primary bile acids appea red as a protective factor against cancer: (OR = 0.09, 95% CI 0.02-0.54), H igh values of cholesterol were associated with cancer risk (OR2 = 5.8, 95% CI 1.3-26.6; OR3 6.4, 95% CI 1.3-31.4). High values of cholesterol were mor e frequently observed in patients with large adenomas than in controls (OR2 = 8.5, 95% CI 1.9-37.5; OR3 = 4.3, 95% CI 0.9-20.9). Neutral sterols, chol esterol especially, may play a role in adenoma growth and adenoma transform ation into carcinoma. Persistence of primary bile acids may afford protecti on. (C) 1999 Lippincott Williams & Wilkins.