Analysis of KRAS, BRAF and NRAS in Patients with Colorectal Cancer: the First Report of Western Iran

摘要

Background: KRAS/NRAS/BRAF mutations are useful markers for predicting responses to anti-EGFR monoclonal antibodies in metastatic colorectal cancers. The aim of this study was to investigate the clinicopathological characteristics and distribution by tumor localization of KRAS mutations in metastatic colorectal cancer and analysis of NRAS and BRAF in the patients in Western Iran. Materials and Methods: Between May 2008 and November 2014, Thirty- three patients with metastatic or high risk CRC were included in our study. DNA was extracted by FFPE QIAGEN Kit and also KRAS/NRAS and BRAF V600E were analyzed using allele specific PCR primers and pyrosequencing. The overall survival for patients was plotted by GraphPad Prism 5 software. Results: The mean of age for patients at diagnosis was 57.67±13.20 years (range, 28-80 years), 19 patients (57.6%) were male. Of 33 patients, 9 patients (27.3%) were high risk and rest of patients had metastasis that metastasis was more to liver and lung, respectively. Of 33 patients, 21 patients (63.6%) have KRAS wild-type and 12 patients (27.3%) have KRAS mutation. Also, 5 samples of patients were checked for BRAF and NRAS. The mean overall survival for patients with metastatic colorectal cancer was 20 months. Location of tumor in 32 patients with metastatic colorectal cancer was left-side colon. Conclusions: NRAS/BRAF testing should be used together and with KRAS genotype to select patients who will likely benefit from anti-EGFR therapy and also location of tumor probably in patients with metastatic colorectal cancer in western Iran is more on left-side colon that it needs other studies with greater volume of patients.