There are very few studies about K-RAS mutations in colorectal cancer (CRC) from developing countries such as Iran. It is therefore essential to conduct studies to learn about the molecular signature of such tumors, allowing the determination of an appropriate management plan. In the present study, we aimed to determine the frequency and types of K-RAS mutations among patients with CRC in Iran.Formalin-fixed paraffin-embedded specimens of 100 cases of CRC were collected from hospitals affiliated with Shiraz University of Medical Sciences (June 2011 to June 2013). All of the H& E slides were examined and proper slide with a minimum of necrosis and maximum of well-preserved tumor cells (at least 70% tumor in each slide) were selected. Recurrent, metastatic, and post chemotherapy cases were excluded from the study. Mutation of codons 12 and 13 of K-RAS gene by PCR was performed, followed by direct sequencing by Sanger method.From 100 eligible cases (55 male and 45 females with mean age of 59 years), 32% had mutant K-RAS gene; the most common substitution was 12G>C followed by 12G>A and 13G>A, respectively.It is found that K-RAS mutation rate, among the selected population of the southern province of Iran, was as high as 32% (codon 12: 71.8% and in codon 13: 25% and one in both codons: 3.1%).

Background: Ovarian carcinoma is one of the leading causes of cancer-related death among females. K-RAS codon 12 mutations are commonly occurring mutations in different types of cancers and leads to resistance against anti-EGFR therapeutics. Hence, determination of mutations in k-RAS gene is crucial for predicting response to anti-EGFR therapies. This study aimed to evaluate the prevalence of k-RAS gene mutations and CA125 tumor marker in patients with ovarian carcinoma in Tabriz city. Methods: Genomic DNA was extracted from 67 tissues pertained to women with ovarian carcinoma. Mutations in codon 12 and 13 of k-RAS gene were analyzed by Nested PCR and RFLP methods. Titer of CA125 tumor marker was determined by ELISA. Results: Among the 67 patients, 7 patients (10. 4%) had mutation in k-RAS codon 12 while none of them had mutation in k-RAS codon 13. Based on the results, the frequency of various genotypes were 89. 55%, 10. 44%, and 0%, for GG, GA, and AA alleles, respectively. The p-value for stage I and Grade I tumors were 0. 022 and 0. 04, respectively, indicating a statistically significant correlation between codon 12 mutation and stage I and Grade I tumors. Furthermore, we found significant correlations among CA125 tumor marker titers and histological grade (p<0. 000) and stage (p<0. 000). The mean serum CA125 tumor marker levels in malignant carcinomas were 499. 84 U/ml. Conclusion: The results in this study indicated high prevalence of k-RAS codon 12 mutations and high titer of CA125 tumor marker in patients with ovarian carcinoma in the study region.