RECTAL EPITHELIAL PROLIFERATION IN PERSONS WITH OR WITHOUT A HISTORY OF ADENOMA AND ITS ASSOCIATION WITH DIET AND LIFE-STYLE HABITS

BACKGROUND. Rectal epithelial proliferation (REP) measurements are use d as a biomarker of risk for colorectal neoplasia and response to chem oprevention. The authors evaluated REP in screenees with and without a history of adenoma and its BACKGROUND. Rectal epithelial proliferatio n (REP) measurements are used as a association with demographic and ad enoma characteristics, diet, and other lifestyle habits. METHODS. Long term lifestyle habits were evaluated and proliferation assessed by in vitro bromodeoxyuridine labeling of rectal biopsies in 223 screenees, 132 of whom had adenomas removed > 3 years previously. Analyses inclu ded the total population, screenees with a previous history of adenoma s and adenoma free screenees separately, and a subgroup of 55 matched adenoma cases and controls.RESULTS. Crypt proliferation measurements w ere not elevated in screenees with a history of adenomas compared with adenoma free screenees (mean total labeling index [LI] of 4.8% and 4. 9%, respectively). This was confirmed by the case-control analysis, in which the LI of the most superficial crypt compartment was lower in t he adenoma cases (P = 0.05). Moreover, their total LI correlated negat ively with the number of adenomas removed previously (P < 0.01). Proli feration was more frequent in the most superficial crypt compartments of female adenoma free screenees than in female screenees with a histo ry of adenomas (P = 0.02), and in men age > 65 years compared with you nger men (P = 0.06). In the total population, negative Spearman rank c orrelations were found between total LI and long term dietary intake o f calcium (correlation coefficient [r] = -0.15; P = 0.02), LI of the t wo most superficial crypt compartments and intake of fiber (r = -0.18; P = 0.01), water (r = -0.12; P = 0.08), and carbohydrates (not signif icant). A positive correlation was found between LI of the most superf icial crypt compartment and cigarette smoking (r = 0.4; P = 0.02). CON CLUSIONS. REP measurements did not discriminate between screenees with a history of adenomas and adenoma free screenees. Long-term lifestyle habits, gender, and age were associated with REP levels and need to b e considered when evaluating human intervention studies. Cancer 1998;8 3:1319-27. (C) 1998 American Cancer Society.