title: [KRAS gene somatic mutations in Chilean patients with colorectal cancer].
abstract: BACKGROUND
  The molecular testing of KRAS mutation status in metastatic colorectal cancer patients is mandatory to identify patients eligible for anti-epidermal growth factor receptor monoclonal antibody therapy.
  
  
  OBJECTIVE
  To report the frequency of KRAS gene mutations in Chilean patients with colorectal cancer (CRC).
  
  
  METHODS
  A cohort of 262 Chilean patients with CRC aged 26 to 90 years (53% males), was studied. KRAS mutation status was analyzed by real-time polymerase chain reaction and correlated with clinicopathological data.
  
  
  RESULTS
  Ninety-eight patients (37%) were positive for KRAS mutations. G12D was the most common mutation with a frequency of 36.7%, followed by G12V (25.5%), G13D (17.3%), G12A (7.1%), G12C (6.1%), G12S (5.1%) and G12R (2%). The frequency of the mutation in left, right colon and rectal tumors was 37.8, 32.6 and 44.9%, respectively. Among tumors with mutations, 86.7% were well or moderately differentiated tumors and the rest were poorly differentiated. No significant associations between KRAS gene mutations and other clinicopathological features of the tumor were observed.
  
  
  CONCLUSIONS
  The frequencies of KRAS mutations reported in this study are similar to frequencies reported for European and North-American populations, lower than in a Spanish study and higher than in a Peruvian study.
authors.forename: Claudia
authors.initials: C
authors.lastname: Hurtado
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Encina
authors.forename: Ana María
authors.initials: AM
authors.lastname: Wielandt
authors.forename: Alejandro José
authors.initials: AJ
authors.lastname: Zárate
authors.forename: Magdalena
authors.initials: M
authors.lastname: Castro
authors.forename: Katya
authors.initials: K
authors.lastname: Carrillo
authors.forename: Udo
authors.initials: U
authors.lastname: Kronberg
authors.forename: Francisco
authors.initials: F
authors.lastname: López-Köstner
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002677:Chile / Q000208:ethnology; D015179:Colorectal Neoplasms / Q000208:ethnology / Q000235:genetics* / Q000473:pathology; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000235:genetics; D004815:Epidermal Growth Factor / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009361:Neoplasm Invasiveness / Q000235:genetics; D011446:Prospective Studies; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D060888:Real-Time Polymerase Chain Reaction; D012737:Sex Factors; D018631:ras Proteins / Q000235:genetics*
chemical_list: D004273:DNA, Neoplasm; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D004815:Epidermal Growth Factor; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins