title: The Frequency and Type of K-RAS Mutations in Mexican Patients With Colorectal Cancer: A National Study.
abstract: BACKGROUND
  Current metastatic colorectal cancer (mCRC) therapy uses monoclonal antibodies against the epidermal growth factor receptor. This treatment is only useful in the absence of K-RAS gene mutations; therefore the study of such mutations is part of a personalized treatment. The aim of this work is to determine the frequency and type of the most common K-RAS mutations in Mexican patients with metastatic disease by nucleotide sequencing.
  
  
  METHODS
  We studied 888 patients with mCRC from different regions of Mexico. The presence of mutations in exon 2, codons 12 and 13, of the K-RAS gene was determined by nucleotide sequencing.
  
  
  RESULTS
  Patients exhibited K-RAS gene mutations in 35% (310/888) of cases. Mutation frequency of codons 12 and 13 was 71% (221/310) and 29% (89/310), respectively. The most common mutation (45.7%) in codon 12 was c.35G>A (p.G12D), whereas the one in codon 13 was c.38G>A (p.G13D) (78.7%).
  
  
  CONCLUSIONS
  Given the frequency of K-RAS mutations in Mexicans, making a genetic study before deciding to treat mCRC patients with monoclonal antibodies is indispensable.
authors.affiliation: *Genomic Bioanalysis Laboratory, Vitagénesis, SA de CV ‡Facultad de Medicina, UANL §ISSSTE Hospital Regional **Hospital Regional de Especialidades IMSS 25 ‡‡Clínica Opción Oncología, Monterrey, Nuevo León †Instituto de Medicina Forense, Universidad Veracruzana, Boca del Río, Veracruz ∥Hospital General Regional IMSS 6 #IMSS Hospital General de Zona No 6, Ciudad Madero, Tamaulipas ¶Hospital General, Chihuahua, Chihuahua ††Laboratorio Ramos, Ciudad Obregón, Sonora, Mexico.
authors.forename: Susana G
authors.initials: SG
authors.lastname: Cárdenas-Ramos
authors.forename: Gregorio
authors.initials: G
authors.lastname: Alcázar-González
authors.forename: Luisa M
authors.initials: LM
authors.lastname: Reyes-Cortés
authors.forename: Abdiel A
authors.initials: AA
authors.lastname: Torres-Grimaldo
authors.forename: Ana L
authors.initials: AL
authors.lastname: Calderón-Garcidueñas
authors.forename: José
authors.initials: J
authors.lastname: Morales-Casas
authors.forename: Patricia
authors.initials: P
authors.lastname: Flores-Sánchez
authors.forename: Raúl
authors.initials: R
authors.lastname: De León-Escobedo
authors.forename: Antonio
authors.initials: A
authors.lastname: Gómez-Díaz
authors.forename: Carmen
authors.initials: C
authors.lastname: Moreno-Bringas
authors.forename: Jorge
authors.initials: J
authors.lastname: Sánchez-Guillén
authors.forename: Pedro
authors.initials: P
authors.lastname: Ramos-Salazar
authors.forename: César
authors.initials: C
authors.lastname: González-de León
authors.forename: Hugo A
authors.initials: HA
authors.lastname: Barrera-Saldaña
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use; D000068258:Bevacizumab / Q000627:therapeutic use; D000068818:Cetuximab / Q000627:therapeutic use; D003062:Codon; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000032:analysis*; D005091:Exons; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico; D059645:Mutation Rate; D009362:Neoplasm Metastasis; D057285:Precision Medicine; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics*
chemical_list: D000970:Antineoplastic Agents; D003062:Codon; D004273:DNA, Neoplasm; C117307:KRAS protein, human; D000068258:Bevacizumab; D016283:Proto-Oncogene Proteins p21(ras); D000068818:Cetuximab