K-ras mutations in nonmucinous ovarian epithelial tumors: a molecular analysis and clinicopathologic study of 144 patients.

To assess the putative prognostic value of K-ras mutations in nonmucinous ovarian tumors, the authors looked for K-ras point mutations at codons 12 and 13 in 144 nonmucinous ovarian tumors. A series of 144 consecutive, unselected, archival, nonmucinous ovarian tumors (35 benign, 12 borderline, and 97 malignant) were studied. K-ras mutations at codons 12 and 13 were determined by polymerase chain reaction using the restriction fragment length polymorphism method with mismatched nested primers. Extensive clinicopathologic and follow-up data on all patients were evaluated. The overall prevalence of K-ras mutations at codons 12 and 13 was 30.5% (44/144). In benign tumors, it was 20% (7/35); in borderline tumors, 25% (3/12); and in carcinomas, 35% (34/97). The presence of K-ras point mutations did not correlate with survival. Among the benign tumors, K-ras mutations were detected in three Brenner tumors with a mucinous component. These results indicate that K-ras mutations are not initial events in the pathogenesis of nonmucinous ovarian tumors and do not appear to be related to survival.