Detection of KRAS and BRAF mutations in colorectal carcinoma: Roles for high-sensitivity locked nucleic acid-PCR sequencing and broad-spectrum mass spectrometry genotyping Journal Article


Authors: Arcila, M.; Lau, C.; Nafa, K.; Ladanyi, M.
Article Title: Detection of KRAS and BRAF mutations in colorectal carcinoma: Roles for high-sensitivity locked nucleic acid-PCR sequencing and broad-spectrum mass spectrometry genotyping
Abstract: KRAS and BRAF mutations predict the resistance of colorectal carcinomas to therapy targeted to the epidermal growth factor receptor, but their detection can be challenging because of high testing volume, frequently low tumor content, and the spectrum of rarer mutations in these genes. To address these issues, we evaluated a locked nucleic acid (LNA)-PCR sequencing assay to detect low levels of mutant DNA, and we also evaluated a mass spectrometry genotyping assay (Sequenom, San Diego, CA) that is suitable for broad mutation screening. Clinical cases (n = 308) previously tested for KRAS and BRAF by standard sequencing were retested by LNA-PCR sequencing incorporating an LNA oligonucleotide to suppress amplification of nonmutant DNA, and by a Sequenom assay panel targeting common mutations in both genes. Standard sequencing detected 121 KRAS (39%) and 10 BRAF mutations; retesting with the LNA-based method and the Sequenom assay detected 19 (140/308, 45%) and 6 (127/308, 41%) additional KRAS mutants, respectively. One additional BRAF mutant was detected by the Sequenom assay. The analytical sensitivities were 0.3% for both KRAS and BRAF by LNA-PCR and from 1% to 10% for the Sequenom assays, depending on the specific mutation. Given these results, standard sequencing is suboptimal for mutation detection in metastatic and treated lesions even with predissection for tumor enrichment. High-sensitivity LNA-PCR sequencing detects significantly more mutations, whereas the Sequenom platform shows intermediate sensitivity but offers significant advantages for broader mutation screening. Copyright © 2011 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.
Keywords: gene mutation; polymerase chain reaction; mass spectrometry; metastasis; epidermal growth factor receptor; genotype; colorectal carcinoma; oncogene; oncogene k ras; locked nucleic acid; oncogene braf
Journal Title: Journal of Molecular Diagnostics
Volume: 13
Issue: 1
ISSN: 1525-1578
Publisher: Elsevier Science, Inc.  
Date Published: 2011-01-01
Start Page: 64
End Page: 73
Language: English
DOI: 10.1016/j.jmoldx.2010.11.005
PROVIDER: scopus
PMCID: PMC3070595
PUBMED: 21227396
DOI/URL:
Notes: --- - "Export Date: 4 March 2011" - "CODEN: JMDIF" - "Source: Scopus"
Altmetric
Citation Impact
BMJ Impact Analytics
MSK Authors
  1. Khedoudja Nafa
    243 Nafa
  2. Marc Ladanyi
    1326 Ladanyi
  3. Chyau-Yueh Christopher Lau
    20 Lau
  4. Maria Eugenia Arcila
    657 Arcila