title: KRAS mutation profile differences between rectosigmoid localized adenocarcinomas and colon adenocarcinomas.
abstract: BACKGROUND
  Colorectal cancer has a heterogeneous nature that is influenced by the tumour site. Many improvements have been made in identifying and characterizing the genetic alterations between colon and rectal cancers. However, there is not enough information about KRAS mutational differences between rectosigmoid and colon cancers arising elsewhere in the large bowel. The aim of this study was to determine the differences in the frequency of KRAS genetic alterations between rectosigmoid cancers and colon cancers.
  
  
  METHODS
  Eighty-four patients diagnosed with colorectal cancer were included in this study. Genomic DNA was extracted from formalin-fixed paraffin-embedded tumour tissue sections. KRAS mutation analysis which was designed to detect the seven most common KRAS gene mutations (Gly12Ala, Gly12Asp, Gly12Arg, Gly12Cys, Gly12Ser, Gly12Val and Gly13Asp) was performed. Chi-square test was used to test the association between mutation status and other variables.
  
  
  RESULTS
  This study represents the first KRAS mutational results from Turkish rectosigmoid cancer patients. The KRAS mutation frequency of rectosigmoid tumours is higher (34.3%, 12/35) than that of colon-localized tumours (30.6%, 15/49). However, there is no significant correlation between the KRAS mutation status and tumour location (rectosigmoid and colon).
  
  
  CONCLUSIONS
  KRAS mutation analysis has a predictive and prognostic value in identifying tumours that may be resistant to treatment. Our study shows that differences in the biological behaviour of rectosigmoid and colon cancers should be considered. This finding highlights the importance of personalized cancer management, which could be assisted by cancer genotyping tools.
authors.affiliation: 1 Department of Basic Oncology, Institute of Oncology, 2 Department of Medical Informatics and Biostatistics, Faculty of Medicine, 3 Department of Surgery, Faculty of Medicine, 4 Department of Pathology, Faculty of Medicine, 5 Department of Preventive Oncology, Institute of Oncology, 6 Department of Medical Oncology, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Yasemin
authors.initials: Y
authors.lastname: Baskin
authors.affiliation: 1 Department of Basic Oncology, Institute of Oncology, 2 Department of Medical Informatics and Biostatistics, Faculty of Medicine, 3 Department of Surgery, Faculty of Medicine, 4 Department of Pathology, Faculty of Medicine, 5 Department of Preventive Oncology, Institute of Oncology, 6 Department of Medical Oncology, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Yusuf Kagan
authors.initials: YK
authors.lastname: Dagdeviren
authors.affiliation: 1 Department of Basic Oncology, Institute of Oncology, 2 Department of Medical Informatics and Biostatistics, Faculty of Medicine, 3 Department of Surgery, Faculty of Medicine, 4 Department of Pathology, Faculty of Medicine, 5 Department of Preventive Oncology, Institute of Oncology, 6 Department of Medical Oncology, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Gizem
authors.initials: G
authors.lastname: Calibasi
authors.affiliation: 1 Department of Basic Oncology, Institute of Oncology, 2 Department of Medical Informatics and Biostatistics, Faculty of Medicine, 3 Department of Surgery, Faculty of Medicine, 4 Department of Pathology, Faculty of Medicine, 5 Department of Preventive Oncology, Institute of Oncology, 6 Department of Medical Oncology, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Aras Emre
authors.initials: AE
authors.lastname: Canda
authors.affiliation: 1 Department of Basic Oncology, Institute of Oncology, 2 Department of Medical Informatics and Biostatistics, Faculty of Medicine, 3 Department of Surgery, Faculty of Medicine, 4 Department of Pathology, Faculty of Medicine, 5 Department of Preventive Oncology, Institute of Oncology, 6 Department of Medical Oncology, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Sulen
authors.initials: S
authors.lastname: Sarioglu
authors.affiliation: 1 Department of Basic Oncology, Institute of Oncology, 2 Department of Medical Informatics and Biostatistics, Faculty of Medicine, 3 Department of Surgery, Faculty of Medicine, 4 Department of Pathology, Faculty of Medicine, 5 Department of Preventive Oncology, Institute of Oncology, 6 Department of Medical Oncology, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Hulya
authors.initials: H
authors.lastname: Ellidokuz
authors.affiliation: 1 Department of Basic Oncology, Institute of Oncology, 2 Department of Medical Informatics and Biostatistics, Faculty of Medicine, 3 Department of Surgery, Faculty of Medicine, 4 Department of Pathology, Faculty of Medicine, 5 Department of Preventive Oncology, Institute of Oncology, 6 Department of Medical Oncology, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Ilhan
authors.initials: I
authors.lastname: Oztop
keywords: KRAS mutations; Rectosigmoid cancer; colon cancer
references.citation: BMC Cancer. 2013 Apr 23;13:200
references.pmid: 23617638
references.citation: Jpn J Clin Oncol. 2013 Jul;43(7):706-12
references.pmid: 23657052
references.citation: Oncology. 2009;77 Suppl 1:57-68
references.pmid: 20130433
references.citation: PLoS One. 2012;7(5):e36653
references.pmid: 22586484
references.citation: CA Cancer J Clin. 2012 Jan-Feb;62(1):10-29
references.pmid: 22237781
references.citation: Gut. 2005 Mar;54(3):374-84
references.pmid: 15710986
references.citation: Med Oncol. 2013;30(3):617
references.pmid: 23729268
references.citation: Anticancer Res. 2006 Jul-Aug;26(4B):2833-40
references.pmid: 16886602
references.citation: Nucleic Acids Res. 2011 Jan;39(Database issue):D945-50
references.pmid: 20952405
references.citation: Anticancer Agents Med Chem. 2012 Feb;12(2):163-71
references.pmid: 22043994
references.citation: J Clin Oncol. 2004 Nov 15;22(22):4584-94
references.pmid: 15542810
references.citation: J Clin Oncol. 2010 Jan 20;28(3):466-74
references.pmid: 20008640
references.citation: J Natl Cancer Inst. 2012 Feb 8;104(3):228-39
references.pmid: 22247021
references.citation: Biochim Biophys Acta. 2011 Dec;1816(2):199-208
references.pmid: 21791238
references.citation: Dis Colon Rectum. 2009 Jul;52(7):1304-11
references.pmid: 19571709
references.citation: J Pathol. 2001 Sep;195(2):171-8
references.pmid: 11592095
references.citation: J BUON. 2012 Jul-Sep;17(3):575-80
references.pmid: 23033302
references.citation: J Pathol. 2009 Dec;219(4):435-45
references.pmid: 19824059
references.citation: J BUON. 2013 Jan-Mar;18(1):124-30
references.pmid: 23613397
references.citation: J Clin Oncol. 2009 Apr 20;27(12):2091-6
references.pmid: 19188670