Deletion analysis of chromosome 8p in sporadic colorectal adenomas

In order to assess the stage of colorectal tumorigenesis at which chromosome 8p loss of heterozygosity (LOH) occurs, 56 sporadic adenomas were examined for LOH at four polymorphic loci which show frequent LOH in carcinomas. LOH was found in only 5 out of 51 (9.8%) informative adenomas, whereas studies with the same markers in 85 informative carcinomas showed a LOH of 45%. The adenomas showing LOH were all in the 'high-risk' clinicopathological category, being 10 mm or more in diameter and showing tubulovillous architecture. It is concluded that the chromosome 8p locus is involved preferentially in the development of carcinomas rather than adenomas.