title: Genetic analysis in APC, KRAS, and TP53 in patients with stomach and colon cancer.
abstract: BACKGROUND
  Stomach cancer (SC) and colorectal cancer (CRC) present with high rates of incidence and mortality in the worldwide population. These 2 tumors are characterized by great genetic heterogeneity. Up to now, there have been no molecular studies that analyze the mutations in the APC, KRAS, and TP53 genes in the Colombian/Latin American population.
  
  
  OBJECTIVE
  To analyze mutations in the APC, KRAS, and TP53 genes through direct sequencing in 59 patients with SC and CRC.
  
  
  METHODS
  Twenty-nine patients with SC and 30 with CRC were studied. An analysis of the mutations of the 3 genes was carried out using polymerase chain reaction and direct sequencing techniques.
  
  
  RESULTS
  A 30.5% total mutation frequency was found. The most frequently mutated gene was APC (15.3%), followed by KRAS (10.1%) and TP53 (5.1%). The CRC samples had a mutation frequency of 46.7% and it was 13.3% in the SC samples (P=.006). No mutations occurred simultaneously in the 3 genes. Mutations in 2 genes were found in only 6 tumor samples (10%). There was also a high frequency of polymorphisms in both types of cancer, the most common of which was the rs41115 polymorphism, located on the APC gene.
  
  
  CONCLUSIONS
  The APC, KRAS, and TP53 gene mutations were more common in CRC than in SC. Our results suggest the existence of different genetic pathways in the carcinogenesis of SC and CRC and they also reveal a particular mutation frequency in the Colombian patients studied; this could be influenced by factors related to the environment, ethnicity, and lifestyle of this population.
authors.affiliation: Unidad de Genética Médica, Departamento de Pediatría, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia.
authors.forename: K A
authors.initials: KA
authors.lastname: Palacio-Rúa
authors.affiliation: Departamento de Cirugía, Facultad de Medicina, Universidad de Antioquia, Hospital San Vicente de Paúl, Medellín, Colombia.
authors.forename: L F
authors.initials: LF
authors.lastname: Isaza-Jiménez
authors.affiliation: Departamento de Patología, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia.
authors.forename: E
authors.initials: E
authors.lastname: Ahumada-Rodríguez
authors.affiliation: Unidad de Genética Médica, Departamento de Pediatría, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia. Electronic address: cmuneton@gmail.com.
authors.forename: C M
authors.initials: CM
authors.lastname: Muñetón-Peña
mesh_terms: D025601:Adenomatous Polyposis Coli Protein / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003110:Colonic Neoplasms / Q000453:epidemiology / Q000235:genetics*; D003430:Cross-Sectional Studies; D004252:DNA Mutational Analysis; D005260:Female; D005787:Gene Frequency; D006801:Humans; D007843:Latin America / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D013274:Stomach Neoplasms / Q000453:epidemiology / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*; D055815:Young Adult; D018631:ras Proteins / Q000235:genetics*
chemical_list: C555337:APC protein, human; D025601:Adenomatous Polyposis Coli Protein; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins
keywords: Colorectal cancer; Cáncer colorrectal; Cáncer de estómago; Genetic heterogeneity; Genetic instability; Heterogeneidad genética; Inestabilidad genética; Polimorfismo; Polymorphism; Stomach cancer