RISK-FACTORS FOR CANCERS AND ADENOMAS OF THE LARGE-INTESTINE - AN ANALYSIS OF FOOD ITEMS AND REPRODUCTIVE FACTORS

Study objective - The aim was to study the association between colorectal cancers or adenomas and dietary/reproductive factors. The risk associated with the intake of bread, meat, and vegetables were analysed, as well as parity, age at menopause, hormonal treatment and use of oral contraceptions. Design - The study was conducted as a case-control study within a large randomized screening trial in Denmark. Participants - Cases were selected from individuals with a positive Hemoccult-II test and age-matched controls were selected from test negatives. Diagnosis was later confirmed by colonoscopy and women with cancer or adenoma formed the final case groups. A total of 49 colorectal cancer patients and 172 with adenomas were examined, 362 test negatives in the screening trial served as controls. One hundred and sixty four of the test positives and 157 of the test negatives were women. Measurements and main results - Data were obtained through personal telephone inter- viewing by a female nutritionist who interviewed cases before clinical examination of test positives. Cancer patients had a lower intake of bread and potatoes but the differences were not statistically significant. A similar pattern was seen in the adenoma group and in this group the intake of bread was significantly lower than in controls. None of the reproductive factors examined showed any statistically significant association with colorectal cancer or adenoma. The amount of information in the cancer study is, however, limited due to small sample sizes. Conclusions - A previous analysis had shown a protective effect of dietary fibres, which probably why a low intake of bread and potatoes was associated with cases of colorectal cancer or adenomas. As in most other studies, none of the reproductive factors studied appeared to be strong risk factor for colorectal cancer or adenoma.