K-ras alterations in Danish ovarian tumour patients. From the Danish "Malova" Ovarian Cancer study

OBJECTIVE: Activation of ras oncogenes has been demonstrated in ovarian tumours. All the reported studies are based on a relatively small number of patients and the results therefore remain a subject of debate.

METHODS: In this study, we analyzed the presence of mutations at codons 12 and 13 of the K-ras gene in 165 Danish women with ovarian tumours, including 138 invasive ovarian cancers and 27 borderline ovarian tumours, using a restriction fragment length polymorphism-polymerase chain reaction technique and evaluated whether such alterations were associated with the clinicopathological parameters of the patients and survival.

RESULTS: K-ras codon 12 gene mutations were found in 8.7% of ovarian cancer patients and in 14.8% of the borderline ovarian tumour patients. A K-ras codon 13 gene mutation was found in 1.5% of ovarian cancer patients. K-ras mutations were found with a significantly higher frequency in mucinous tumours compared to serous tumours (P = 0.011).

CONCLUSIONS: Mutation frequency was correlated with the histological type of tumour, but not with stage, radicality of operation, and age. Furthermore, no significant difference in survival was demonstrated between patients with or without K-ras mutation, neither in the univariate nor in the multivariate survival analyses.