ADENOMA-CARCINOMA SEQUENCE OF COLORECTUM - PREVALENCE OF K-RAS GENE MUTATION IN ADENOMAS WITH INCREASING DEGREE OF DYSPLASIA AND ANEUPLOIDY

One hundred and fifty colorectal adenomas were investigated in order t o detect the presence of K-ras gene mutation. The adenomas were classi fied according to the severity of the histological lesion (mild, moder ate, or severe dysplasia and carcinomatous transformation) and to the degree of aneuploidy. K-ras mutation was found in 30.8% of cases, most ly consisting of a point mutation of codon 12. K-ras mutation was more frequently found in adenomas >1 cm and in the villous type. No correl ation was otherwise demonstrable with the ploidy pattern of the lesion .