title: [Screening for Lynch syndrome in colorectal cancer].
abstract: OBJECTIVE
  To evaluate the application of mismatch repair (MMR) genes proteins expression to screen for Lynch syndrome in colorectal cancer patients.
  
  
  METHODS
  One hundred consecutive colorectal cancers cases collected from 2012 to 2013 were tested immunohistochemically for the protein expression of MLH1, MSH2, MSH6 and PMS2, and also by the ARMS method for the mutation status of BRAF genes in those cases lacking protein expression for MLH1.
  
  
  RESULTS
  The result of MMR immunocytochemistry showed that nine of 100 cases lacked MMR protein expression, including three cases each that were MLH1-/PMS2- and MSH2-/MSH6- respectively, two cases were MLH6- and one case was PMS2-; overall, the majority of these cases lacked protein expression of MLH1 and MSH2. The BRAF genes mutation test showed one case of mutation, indicating that the patient might have MLH1 gene methylation as a result of the mutation of BRAF genes, and that was a sporadic case. The age of onset for patients lacking MMR protein expression was lower than patients with sporadic colorectal cancer (P = 0.011). Colorectal cancers associated with the lack of MMR protein expression mostly occurred in the right colon (P = 0.001), and histomorphologically were often accompanied by mucinous adenocarcinoma (P = 0.010) and tumor lymphocytic infiltration.
  
  
  CONCLUSIONS
  Immunohistochemical staining for MMR proteins in patients with colorectal cancer, accompanied by testing for BRAF genes mutation, may be an effective approach to screen for Lynch syndrome.
authors.affiliation: Department of Pathology, General Hospital of Jinan Military Command, Jinan 250031, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Pathology, General Hospital of Jinan Military Command, Jinan 250031, China.
authors.forename: Yongcheng
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Pathology, General Hospital of Jinan Military Command, Jinan 250031, China.
authors.forename: Cuicui
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Pathology, General Hospital of Jinan Military Command, Jinan 250031, China.
authors.forename: Ruixue
authors.initials: R
authors.lastname: Cao
authors.affiliation: Department of Pathology, General Hospital of Jinan Military Command, Jinan 250031, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Pathology, General Hospital of Jinan Military Command, Jinan 250031, China.
authors.forename: Jiyuan
authors.initials: J
authors.lastname: Ding
authors.affiliation: Department of Pathology, General Hospital of Jinan Military Command, Jinan 250031, China. E-mail: gm2227@sina.com.
authors.forename: Ming
authors.initials: M
authors.lastname: Geng
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000175:diagnosis* / Q000235:genetics; D053843:DNA Mismatch Repair; D006801:Humans; D007150:Immunohistochemistry; D000070957:MutL Protein Homolog 1; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C501486:MLH1 protein, human; D009687:Nuclear Proteins; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D000070957:MutL Protein Homolog 1