Evaluation of p53 and K-ras Gene Mutations Frequency in Iraqi Women with Ovarian Carcinoma

Abstract

Ovarian cancer represents the fourth most frequent type of cancer among females and is the leading cause of death from gynecological cancer in the western world. More recently, ovarian tumors have been broadly classified into two distinct groups with unique histological, clinical and molecular profiles. Type I tumors in which BRAF and K-ras somatic mutations are relatively common, and type II tumors which display high levels of genomic instability with few common mutations, other than TP53, which is altered in over 90% of the cases. In the present study 58 samples with newly diagnosed ovarian cancer were analyzed for detecting the frequency of p53 and K-ras gene mutations in Iraqi ovarian cancer patients, as well as 15 samples of apparently healthy women used as a control group. The analysis was based on conventional PCR amplification of exons 5 and 7 of the p53 gene and codon 12 of K-ras. For both p53 and K-ras genes, none of healthy control exhibited mutation in those genes. p53 mutations detected in 13(22.4%) of ovarian cancer samples, which was significantly higher in compare with healthy controls (p<0.05). The results showed that out of thirteen mutant ovarian cancer samples, exon-5 mutation was the most frequent and detected in 10 (76.9 %), followed by exon-7 that detected only in 3(23.07%) of cases. Statistically there were no significant differences in mutational rates of p53 gene in patients with age, menopausal state, tumor histological subtypes, and different FIGO stages. K-ras mutation detected in only 3(5.17%) of ovarian cancer samples. There were no significant difference in mutational rates of K-ras gene in patients with age, menopausal state, tumor histological subtypes, and different FIGO stages, but all these three mutant samples with stage I. Out of 58 samples only one patient 1(1.7%) have been identified with mutations in both genes. In conclusion, the present study results show that mutations of the p53 gene are not rare events, and K-ras mutations status is not a prognostic factor in ovarian carcinomas.