Detection of KRAS Mutations in Triple-negative Breast Cancers by Polymerase Chain Reaction

Abstract Background: Recently, it has been proven that KRAS gene mutation analysis is an additional in vitro diagnostic method for determining colorectal cancer patients who will not respond to anti-epidermal growth factor receptor (EGFR) therapy. KRAS mutation status assessment may be important in other EGFR-overexpressed cancers, such as breast cancer tumors. Only 5% of breast tumors are KRAS-mutated, yet 60% of triple-negative breast tumors express EGFR, making them potential targets for EGFR inhibitors. To provide a biological foundation for assessing anti-EGFR therapy, we aimed to examine the frequency of KRAS mutations in triple-negative breast cancer (TNBC). Materials and Methods: Forty breast cancer cases were evaluated. These 40 cases have undergone immunohistochemistry for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 markers which exhibited a negative reaction and were ascertained as triple negative. The mutation status of KRAS was determined by real-time polymerase chain reaction (RT-PCR) to detect wild or mutant types of KRAS. Results: In our study, we observed that, out of the total 40 cases of TNBCs, 14 (35%) cases were of wild type and 26 (65%) cases were mutant type detected by RT-PCR. Conclusion: According to our study, KRAS mutations were detected in TNBCs, and EGFR inhibitors may be effective in the treatment of these tumors, which overexpress EGFR in around 65% of cases.