[Dietary factors and cancer of the colon and rectum in a population based case-control study in Shanghai].

The study was a population-based case control one, to compare possible difference in the risk factors between colonic and rectal cancer. This study showed that: (1) High intake of pork and saturated fat was an important risk factor for colon cancer, and only slightly related to rectal cancer. (2) Low consumption of vegetables especially cruciferous vegetables, rhizome vegetables, sea weeds, legume vegetables, dietary fiber and some vitamins mainly derived from vegetables, e.g. vitamin c and carotene, was associated with an increased risk for both colonic and rectal cancer, and these factors were closer relationship with rectal cancer than colon cancer. (3) High intake of the fried and pickled foods significantly increase the risk of occurrence of these cancers. (4) The ratio of bowel cancer in first degree relatives of colon cancer cases was 2.9 times of control group (P < 0.01), but the ratio for rectal cancer was only 1.6 times (P > 0.05) compared with control group.