Mutations of the Ki-ras oncogene in carcinoma of the endometrium

Mutations of the Ki-ras oncogene in endometrial carcinoma have been reported in Japan, but the prevalence and clinical significance of such mutations in the United States remains unclear. DNA extracted from paraffin sections of 112 carcinomas of the endometrium was amplified by the polymerase chain reaction with mismatched primers that generated a BstNI recognition site with the wild-type codon 12. Loss of this recognition site indicating Ki-ras codon 12 mutations was observed in 13 tumors (11.6%), including 11 endometrioid carcinomas, one undifferentiated carcinoma, and one carcinosarcoma. None of 17 papillary serous-clear cell carcinomas contained Ki-ras codon 12 mutations. These mutations were confirmed and characterized by direct sequencing. We found no evidence of correlation of the presence of Ki-ras mutations with stage, grade, depth of invasion, or clinical outcome. Our results indicate that Ki-ras oncogene mutations in carcinoma of the endometrium may be less prevalent in the United States than in Japan.