Mutation Analysis of KRAS and BRAF Genes in Metastatic Colorectal Cancer: a First Large Scale Study from Iran

  • koochak, Aghigh (Gastrointestinal and Liver Diseases Research Center, Firoozgar Hospital) ;
  • Rakhshani, Nasser (Gastrointestinal and Liver Diseases Research Center, Firoozgar Hospital) ;
  • Niya, Mohammad Hadi Karbalaie (Department Of Virology, Iran University Of Medical Sciences) ;
  • Tameshkel, Fahimeh Safarnezhad (Gastrointestinal and Liver Diseases Research Center, Firoozgar Hospital) ;
  • Sohrabi, Masoud Reza (Gastrointestinal and Liver Diseases Research Center, Firoozgar Hospital) ;
  • Babaee, Mohammad Reza (Gastrointestinal and Liver Diseases Research Center, Firoozgar Hospital) ;
  • Rezvani, Hamid (Department of Oncology, Shahid Beheshti University of Medical Sciences) ;
  • Bahar, Babak (Gastrointestinal and Liver Diseases Research Center, Firoozgar Hospital) ;
  • Imanzade, Farid (Department of Pediatrics, Shahid Beheshti University of Medical Sciences) ;
  • Zamani, Farhad (Gastrointestinal and Liver Diseases Research Center, Firoozgar Hospital) ;
  • Khonsari, Mohammad Reza (Gastrointestinal and Liver Diseases Research Center, Firoozgar Hospital) ;
  • Ajdarkosh, Hossein (Gastrointestinal and Liver Diseases Research Center, Firoozgar Hospital) ;
  • Hemmasi, Gholamreza (Gastrointestinal and Liver Diseases Research Center, Firoozgar Hospital)
  • Published : 2016.03.07


Background: The investigation of mutation patterns in oncogenes potentially can make available a reliable mechanism for management and treatment decisions for patients with colorectal cancer (CRC). This study concerns the rate of KRAS and BRAF genes mutations in Iranian metastatic colorectal cancer (mCRC) patients, as well as associations of genotypes with clinicopathological features. Materials and Methods: A total of 1,000 mCRC specimens collected from 2008 to 2012 that referred to the Mehr Hospital and Partolab center, Tehran, Iran enrolled in this cross sectional study. Using HRM, Dxs Therascreen and Pyrosequencing methods, we analyzed the mutational status of KRAS and BRAF genes in these. Results: KRAS mutations were present in 33.6% cases (n=336). Of KRAS mutation positive cases, 85.1% were in codon 12 and 14.9% were in codon 13. The most frequent mutation at KRAS codon 12 was Gly12Asp; BRAF mutations were not found in any mCRC patients (n=242). In addition, we observed a strong correlation of KRAS mutations with some clinicopathological characteristics. Conclusions: KRAS mutations are frequent in mCRCs while presence of BRAF mutations in these patients is rare. Moreover, associations of KRAS genotypes with non-mucinous adenocarcinoma and depth of invasion (pT3) were remarkable.


Mutation analysis;KRAS;BRAF;metastatic colorectal cancer, pyrosequencing;high resolution melting


Supported by : Iran University of Medical Sciences


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