In order to describe the epidemiological features and explore the risk factors of colon cancer, a population-based case-control study involving 476 cases of colon cancer and 857 controls matched by age and sex was carried out from Sep. 1988 to Aug. 1989. In this paper the risk factors related to colon cancer are reported as follows; The major risk factors of colon cancer in the area were generally in accordance with the prevalent hypothesis, colon cancer in Shanghai urban area may present the characteristics of low risk areas. Analysis of single and multiple factors of food intake frequency and quantity indicated that most vegetables usually cast a protective effect. Males in the highest quartile of intake of vegetables had a OR of 0.4 (P trend

A population-based case-control study of the colorectal cancer was conducted in Shanghai (1988-1990). The contributions of diet and nutrients as risk factors of colon cancer were reported in a previously paper (1990). The study involved 575 incident cases of rectal cancer and 1400 controls at age range from 30-70.The study showed that increased consumption of cruciferous vegetables (Veg), fresh beans, fresh fruits, garlic, sea weeds and Veg oil were inversely related to the risk of rectal cancer. The intake of pork elevated the risk. Dietary fiber, vitamin C and carotene, independent of other nutrients, had the protective effect against developing rectal cancer. The intakes of several lipids, including total fat, saturated, mono-unsaturated, polyunsatura-ted,oleic, linoleic, and linolcnic,were slightly related with the risk of the cancer. Cholesterol significantly decreased the risk for females and had a significant linear trend. Investigation of nutrients revealed that ?-tocopherol and FOCC (fatty acid of odd carbon chain) decreased the relative risk for females. Analyses compared with other studies carried out in the Western countries (high incidence areas) showed that there may be a difference in risk factors of rectal cancer in diet between the Eastern countries (low incidence areas) and the West.