Non-p.V600E BRAF Mutations Are Common Using a More Sensitive and Broad Detection Tool

Am J Clin Pathol. 2015 Oct;144(4):620-8. doi: 10.1309/AJCP85ATMJOZOUDJ.


Objectives: To assess the performance of a next-generation sequencing (NGS) platform for the clinical detection of BRAF mutations.

Methods: In this retrospective quality assessment of an NGS assay, we analyzed BRAF mutations within parts of exons 11 and 15 in 835 neoplastic tissues submitted to our molecular diagnostics laboratory.

Results: The NGS assays detected a BRAF mutation in 5.9% of lung adenocarcinomas, 13% of colorectal cancers, and 44% of melanomas. Mutant allele frequencies were less than 20% in 28% of 88 BRAF-mutated specimens. Two lymph node specimens with subcapsular or infiltrative metastasis showed 1% to 2% mutant alleles. There were 26 unique BRAF mutations in exons 11 and 15, including three novel mutations. Mutations were located outside codon 600 in 39% of BRAF-mutated tumors. Lung adenocarcinomas showed significantly higher non-p.V600E mutations (86%) than did colorectal cancers (23%) and melanomas (34%). The three most common BRAF mutations in lung cancers accounted for only 41% of the observed BRAF mutations (p.D594G [18%], p.V600E [14%], and p.G469A [9%]).

Conclusions: The NGS assay demonstrated a high analytic sensitivity and a broad reportable range for clinical detection of BRAF mutations. Elucidating the spectrum of non-p. V600E BRAF mutations in different malignancies is a first step toward understanding their clinical significance.

Keywords: BRAF; Colorectal cancer; Lung cancer; Melanoma; Next-generation sequencing.

MeSH terms

  • DNA Mutational Analysis / methods*
  • High-Throughput Nucleotide Sequencing / methods*
  • Humans
  • Neoplasms / genetics*
  • Oligonucleotide Array Sequence Analysis
  • Proto-Oncogene Proteins B-raf
  • Retrospective Studies
  • Sensitivity and Specificity
  • Sequence Analysis, DNA / methods*


  • BRAF protein, human
  • Proto-Oncogene Proteins B-raf