NUTRITIONAL FACTORS AND COLON-CARCINOMA - A CASE-CONTROL STUDY INVOLVING FRENCH-CANADIANS IN MONTREAL, QUEBEC, CANADA

BACKGROUND. In a population-based case-control study of colon carcinom a and nutrition involving the francophone community in Greater Montrea l, a total of 402 cases (200 males and 202 females) and 668 controls ( 239 males and 429 females) were interviewed. METHODS. Cases from 1989- 1993 were identified through the admission offices of 5 major francoph one teaching hospitals in Montreal and were ages 35-79 years. Controls matched by age, place of residence, and language were selected by a m odified random digit dialing method. Information on dietary intake was collected with a quantitative food frequency questionnaire. RESULTS. No associations were evident between colon carcinoma and total energy, protein, or carbohydrate consumption, whereas a suggestive inverse as sociation was found with total fat intake, with an odds ratio (OR) of 0.78 (P = 0.0637), and with saturated fat intake as well (OR = 0.71, P = 0.0893). A strongly significant inverse association was found with dietary fiber (OR = 0.50, P = 0.0018). The strongest inverse associati on concerning fiber was found with fiber from vegetable sources (OR = 0.57, P = 0.0096), and a suggestive (although nonsignificant) inverse association (OR = 0.74, P = 0.0687) was found with fiber from fruits. Calcium was inversely associated with risk (OR = 0.69, P = 0.0411), as was dietary intake of vitamin A (OR = 0.67, P = 0.0162), retinol, (OR = 0.069, P = 0.0409), vitamin E (OR = 0.53, P = 0.0028), and alphatoc opherol (OR = 0.63, P = 0.0256). Although there was no association dem onstrated between dietary beta-carotene intake and risk, a suggestive (although nonsignificant) inverse association with intake of other typ es of carotene was observed (OR = 0.76, P = 0.0740). No association wa s found between intake of other nutrients investigated in this study a nd risk of colon carcinoma. CONCLUSIONS. There is strong evidence from epidemiologic studies that high intake of fat and meat are risk facto rs for colorectal carcinoma in humans, whereas high intake of vegetabl e and fruit are inversely associated with risk of colon carcinoma. The findings from this study are in agreement with this observation. (C) 1997 American Cancer Society.