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.
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.
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%).
Given the frequency of K-RAS mutations in Mexicans, making a genetic study before deciding to treat mCRC patients with monoclonal antibodies is indispensable.
*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
Supported by National Council of Science and Technology of Mexico.
The authors declare no conflicts of interest.
Reprints: Hugo A. Barrera Saldaña, PhD, Vitaxentrum, Boulevard Puerta del Sol #1005 Colinas de San Jerónimo, Nuevo León, México 64180. E-mail: email@example.com.