Genetic factors related to the development of carcinoma in digestive organs in alcoholics

Heavy drinkers do not always develop alcoholic liver disease or cancer of the digestive organs, indicating that genetic factors may be involved. Recently, the presence of genetic polymorphisms of cytochrome P4502E1 (2E1) was confirmed. The genotype of 2E1 was separated into three types; type A which is homozygous for the c1 gene, type B which is heterozygous for the c1 and c2 genes, and type C which is homozygous for the c2 genes. In the present study the relationship between genotypes of 2E1 and digestive diseases, including alcoholic liver disease, was analyzed. In healthy controls, the prevalence of types A, B and C was 69%, 31% and 0%, respectively. In patients with esophageal cancer, four out of five patients (80%) were type B, and the prevalence of type B was significantly higher than that in normal controls. These results suggest that the c2 gene of 2E1 may be related to the development of esophageal cancer. In patients with gastric disease, the prevalence of types A and B was 72% and 28%, respectively. In patients with large bowel disease, the prevalence of type A was 83-100%, significantly higher than that in healthy controls. These results suggest that the c2 gene of 2E1 may not be related to the development of large bowel disease. However, the possibility should be considered that the c1 gene of 2E1 may link to its development. In this study, the relationship between the genotype of 2E1 and alcoholic liver disease was also analyzed. All patients with alcoholic liver disease, including one hepatoma, had the c2 gene but not the c1 gene. The frequency of the c2 gene was quite different from that in non-alcoholic liver disease.(ABSTRACT TRUNCATED AT 250 WORDS)