Mutation of K-ras protooncogene is associated with histological subtypes in human mucinous ovarian tumors.

A series of 57 mucinous and 47 serous ovarian tumors (adenomas, tumors of borderline malignancy, and carcinomas) were examined by polymerase chain reaction-single strand conformation polymorphism analysis and direct sequencing for mutations in codons 12, 13, and 61 of K-ras gene. Higher incidence of K-ras mutations was observed in mucinous tumors compared to serous ones. Mutations were detected in 4 of 30 mucinous adenomas (13%), in 4 of 12 mucinous tumors of borderline malignancy (33%), and in 7 of 15 mucinous carcinomas (46%). Only 1 of 17 serous carcinomas (6%) had a mutation of K-ras in serous ovarian tumors. All mutations identified were in codon 12. Detailed analysis revealed that more K-ras mutations in mucinous adenomas were observed in intestinal type (identified in 4 of 13) than in endocervical type (identified in 0 of 17). Thus, K-ras gene codon 12 mutations in mucinous ovarian adenomas appear to be associated with the occurrence of intestinal type adenomas.