[Meta-analysis study on risk factors of colorectal cancer]

OBJECTIVE: To evaluate the risk factors of colorectal cancer in China. METHODS: The results of 14 case-control studies from 1988 to 2000 were analyzed by means of Meta-analysis. The total numbers of cases and controls were 5034 and 5205 respectively. Dersimonian and Laird random effective models were applied in processing data. RESULTS: Light physical activities and dietary fibers were protective factors (pooled OR<0.8); while histories of fecal mucohemorrhage, chronic diarrhea and bowel polyps were highly associated with colorecatal cancer (pooled OR >4) The stratified results indicated that there were probably some differences between OR values of some factors if using different sources of cases and controls or using different data from the north and south of China. CONCLUSION: Risks of colorectal cancer are significantly associated with the histories of intestinal diseases or relative symptoms, fatty food, psychic attack and family history of cancers. The light physical activities and dietary fibers are probably protective factors.