title: [Frequency of loss of heterozygosity on chromosome 17 in intrahepatic cholangiocarcinoma].
abstract: BACKGROUNDS/AIM: Intrahepatic cholangiocarcinoma is the second most common intrahepatic neoplasm. Carcinogenesis is believed to be a multistage process that occurs as a result of mutations in oncogenes and tumor suppressor genes. Loss of heterozygosity (LOH) is the phenotype of genetic instability which has been used as a tool for detecting genetic phenotype alterations. Large number of the molecular alterations have been described in human cancer. Among them, that of p53 is quite common. The aim of this study was to determine the frequency of LOH at chromosome 17p related with p53.
  
  
  METHODS
  Twenty cases who underwent hepatic resection due to intrahepatic cholangiocarcinoma, were included. LOH was analysed with four microsatellite markers by PCR. For the clinicopathologic parameters, tumor size, differentiation, and metastasis were evaluated.
  
  
  RESULTS
  Fifteen patients (75%) showed LOH at one of the loci at the least. Five patients were LOH-high and 10 were LOH-low. The highest frequency of LOH was observed at D17S5 by 38.9%. Those of TP53, D17S796 and D17S513 were 29.4%, 21.4% and 35.3%, respectively. In addition, LOH tended to be more frequent when the tumor is mass forming type, poorly differentiated, or has tumor emboli or vascular invasion.
  
  
  CONCLUSIONS
  This study showed that LOH was positive in 75% on chromosome 17p in intrahepatic cholangiocarcinoma which was relatively frequent at D17S5.
authors.affiliation: Department of Internal Medicine, Kangwon National University College of Medicine, Chuncheon, Korea.
authors.forename: Hyo Jung
authors.initials: HJ
authors.lastname: Kim
authors.forename: Chang Don
authors.initials: CD
authors.lastname: Kang
authors.forename: Sung Joon
authors.initials: SJ
authors.lastname: Lee
authors.forename: Sung Jin
authors.initials: SJ
authors.lastname: Cho
authors.forename: Jae Seon
authors.initials: JS
authors.lastname: Kim
mesh_terms: D000368:Aged; D001650:Bile Duct Neoplasms / Q000235:genetics* / Q000473:pathology; D001653:Bile Ducts, Intrahepatic; D018281:Cholangiocarcinoma / Q000235:genetics* / Q000473:pathology; D002886:Chromosomes, Human, Pair 17; D005260:Female; D005787:Gene Frequency; D016158:Genes, p53; D005819:Genetic Markers; D006801:Humans; D019656:Loss of Heterozygosity; D008297:Male; D008875:Middle Aged
chemical_list: D005819:Genetic Markers