Objective: The alteration in the intestinal metabolism of cholesterol and bile acids in the large bowel has been associated for a long time with the pathogenesis of development of colorectal carcinoma. The objective of the present project was to prove a relationship between the polymorphism of apoE which is the crucial link of the lipoprotein metabolism and the development of adenoma and carcinoma of the large bowel resp. Methods and patients: The investigation comprised 153 patients with adenoma of the large bowel, 121 patients with adenocarcinoma of the large bowel and 166 subjects with a normal colonoscopic finding as control group matched for age and sex with the examined groups. In individual groups DNA analysis of apoE isoforms was performed by the PCR method and subsequently restriction isotyping. Results: The results of the investigation indicate that the distribution of the apoE4 allele is almost identical in patients with adenomas (8.2%) and carcinomas resp. (11.7%) of the large bowel and in healthy controls (10.24%). There is a statistically significant difference between the incidence of apoE4 allele between proximally and distally situated adenomas and carcinomas of the large bowel resp. In proximally situated tumours of the large bowel the apoE4 allele is found in 19.1%, in distally situated ones in 11.67% (p = 0.2526). In the group of patients with proximally situated polyps the apoE4 allele is found in 17.4% and in distally situated ones only in 6.52% (p = 0.283). Conclusion: The results of the investigation prove a statistically significant difference in the incidence of apoE4 allele between proximally and distally situated adenomas and carcinomas resp. of the large intestine. Th reasons why adenomas and carcinomas of the large bowel develop in patients with an apoE4 allele more in the right than in the left colon are not quite clear but may be associated with a change in the intraluminal absorption of cholesterol and the output of faecal bile acids which may potentiate the proliferating capacity of colonocytes in the right colon. We assume that the results of the investigation will contribute to further detection of risk factors participating in the development of sporadic tumours of the large intestine and will make it possible to detect more effectively subjects at risk.

        Key words: apolipoprotein E – colorectal carcinoma – polymorphism