Prevalence of the BRAF p.v600e variant in patients with colorectal cancer from Mexico and its estimated frequency in Latin American and Caribbean populations

This study aimed to investigate the frequency of the somatic BRAF p. V600E in patients with colorectal cancer (CRC) in Mexico and compare it with those estimated for Latin American and Caribbean populations. One hundred and one patients with CRC with AJCC stages ranging I-IV from Western Mexico were included, out of which 55% were male and 61% had AJCC stage III-IV, with a mean age of 60 years. PCR-Sanger sequencing was used to identify the BRAF p. V600E variant. In addition, a systematic literature search in PubMed/Medline database and Google of the 42 countries in Latin America and the Caribbean led to the collection of information on the BRAF p. V600E variant frequency of 17 population reports. To compare the BRAF variant prevalence among populations, a statistical analysis was performed using GraphPad Prism V.6.0. We found that 4% of patients with CRC were heterozygous for the p. V600E variant. The χ2 test showed no significant difference (p>0.05) in p. V600E detection when comparing with other Latin American and Caribbean CRC populations, except for Chilean patients (p=0.02). Our observational study provides the first evidence on the frequency of BRAF p. V600E in patients with CRC from Western Mexico, which is 4%, but increases to 7.8% for all of Latin America and the Caribbean. The patient mean age and genetic descent on the observed frequencies of the variant in populations could influence the frequency differences.