[Detection of Ki-ras oncogene mutations in normal mucosa, adenoma and adenocarcinoma of the colon].

Paraffin embedded tissues, including 41 surgically resected colonic specimens in which separable normal mucosa, adenoma and adenocarcinoma were available, and 10 endoscopically excised colonic adenomas were studied for Ki-ras mutations by RFLP, SSCP and S1 nuclease protection methods. Mutations of Ki-ras codon 12 or 61 were found in 9/41 and 21/41 surgically resected adenomas and adenocarcinomas respectively. One of the ten endoscopically excised adenomas had Ki-ras codon 12 mutation. No mutations of Ki-ras 12 or 61 were detected in normal mucosa. All adenomas with Ki-ras oncogene mutation were over 1cm in diameter and had moderate or severe atypical hyperplasia. Our results indicate that RFLP is the most sensitive method of the three used for detecting oncogene mutations.