title: Effect of β-catenin alterations in the prognosis of patients with sporadic colorectal cancer.
abstract: BACKGROUND
  Wnt pathway activation represents a critical step in the etiology of most of colorectal cancer (CRC) and it is commonly due to mutations in the APC gene, which originates the loss of β-catenin regulatory function. It has been suggested that APC inactivation or β-catenin alteration have similar effects in tumor progression in CRC tumorigenesis.
  
  
  OBJECTIVE
  The aim of this study was to analyze the frequency of β-catenin gene mutation in patients with sporadic CRC and to determine its effect in prognosis.
  
  
  METHODS
  This was a prospective cohort study, which included 345 patients with sporadic CRC. β-Catenin gene mutations in exon 3 were detected by single strand conformation polymorphism (SSCP). Exon 3 deletion was studied by identifying differences in fragment length of specific amplification products. All the altered samples were confirmed by direct sequencing.
  
  
  RESULTS
  In our population, point mutations were detected in 1.8% of the samples and 4.9% of the samples showed deletion. We observed association between exon 3 mutations and increased levels of Carcinoenbryonic Antigen (CEA). In these patients, clinically relevant improvement in overall survival was also observed.
  
  
  CONCLUSIONS
  Frequency of point mutations in exon 3 β-catenin gene is low in our population. It would be interesting to increase the population size to test the clinically relevant influence in the prognosis found, and to test the relation of these events with Microsatellite Instabillity (MSI) pathway. If these findings were confirmed, β-catenin determination would help in the selection of patients with different prognosis.
authors.forename: Sara
authors.initials: S
authors.lastname: Rafael
authors.forename: Silvia
authors.initials: S
authors.lastname: Veganzones
authors.forename: Marta
authors.initials: M
authors.lastname: Vidaurreta
authors.forename: Virginia
authors.initials: V
authors.lastname: de la Orden
authors.affiliation: Department of Genomics, Hospital Clínico San Carlos, Madrid, Spain.
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Maestro
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality / Q000601:surgery; D005260:Female; D014644:Genetic Variation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D060787:Neoplasm Grading; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D016896:Treatment Outcome; D051176:beta Catenin / Q000235:genetics* / Q000378:metabolism
chemical_list: D051176:beta Catenin