title: [Frequency of K-ras mutation in biliary and pancreatic tumors].
abstract: BACKGROUND
  The ras gene family (H-ras, N-ras and K-ras) are oncogenes that mutate frequently in human cancer, specially in tumors of the biliary tract and pancreas.
  
  
  OBJECTIVE
  To determine the frequency of K-ras gene codon 12 mutation in pancreatic and biliary tumors.
  
  
  METHODS
  Samples of 35 gallbladder, 15 ampulla of Vater, 10 biliary tract and 9 pancreatic tumors, were analyzed. The tumor tissue was microdissected from paraffin embedded biopsies. The mutation was detected by a combination of polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP).
  
  
  RESULTS
  Overall, 46% of samples had K-ras gene mutations. Mutation frequency was 80, 56, 50 and 29% for ampulla of Vater, pancreatic, biliary tract and gallbladder tumors, respectively. When compared with the rest, gallbladder tumors had a significantly lower frequency of the mutation. Median survival for biliary tract tumors was 6 months, compared with 65 months for gallbladder tumors (p <0.05).
  
  
  CONCLUSIONS
  Gallbladder carcinoma had the lower frequency of K-ras mutation, when compared with pancreatic, biliary tract and ampulla of Vater tumors.
authors.affiliation: Departamento de Anatomía Patológica, Facultad de Medicina, Universidad de la Frontera. jcroa@ufro.cl
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Roa
authors.forename: Leonardo
authors.initials: L
authors.lastname: Anabalón
authors.forename: Oscar
authors.initials: O
authors.lastname: Tapia
authors.forename: Angélica
authors.initials: A
authors.lastname: Melo
authors.forename: Xabier
authors.initials: X
authors.lastname: de Aretxabala
authors.forename: Iván
authors.initials: I
authors.lastname: Roa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D003062:Codon; D005260:Female; D005706:Gallbladder Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D011905:Genes, ras / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012737:Sex Factors; D016019:Survival Analysis
chemical_list: D003062:Codon