Prospective blinded study of BRAFV600E mutation detection in cell-free DNA of patients with systemic histiocytic disorders
David M Hyman, Eli L Diamond, Cecile Rose T Vibat, Latifa Hassaine, Jason C Poole, Minal Patel, Veronica R Holley, Goran Cabrilo, Timothy T Lu, Maria E Arcila, Young Rock Chung, Raajit Rampal, Mario E Lacouture, Neal Rosen, Funda Meric-Bernstam, José Baselga, Razelle Kurzrock, Mark G Erlander, Filip Janku, Omar Abdel-Wahab, David M Hyman, Eli L Diamond, Cecile Rose T Vibat, Latifa Hassaine, Jason C Poole, Minal Patel, Veronica R Holley, Goran Cabrilo, Timothy T Lu, Maria E Arcila, Young Rock Chung, Raajit Rampal, Mario E Lacouture, Neal Rosen, Funda Meric-Bernstam, José Baselga, Razelle Kurzrock, Mark G Erlander, Filip Janku, Omar Abdel-Wahab
Abstract
Patients with Langerhans cell histiocytosis (LCH) and Erdheim-Chester disease (ECD) have a high frequency of BRAF(V600E) mutations and respond to RAF inhibitors. However, detection of mutations in tissue biopsies is particularly challenging in histiocytoses due to low tumor content and stromal contamination. We applied a droplet-digital PCR assay for quantitative detection of the BRAF(V600E) mutation in plasma and urine cell-free (cf) DNA and performed a prospective, blinded study in 30 patients with ECD/LCH. There was 100% concordance between tissue and urinary cfDNA genotype in treatment-naïve samples. cfDNA analysis facilitated identification of previously undescribed KRAS(G12S)-mutant ECD and dynamically tracked disease burden in patients treated with a variety of therapies. These results indicate that cfDNA BRAF(V600E) mutational analysis in plasma and urine provides a convenient and reliable method of detecting mutational status and can serve as a noninvasive biomarker to monitor response to therapy in LCH and ECD.
Significance: Patients with BRAF(V600E)-mutant histiocytic disorders have remarkable responses to RAF inhibition, but mutation detection in tissue in these disorders is challenging. Here, we identify that analysis of plasma and urinary cfDNA provides a reliable method to detect the BRAF(V600E) mutation and monitor response to therapy in these disorders.
Conflict of interest statement
Author’s Disclosure of Potential Conflicts of Interest
CRTV, LH, JCP, TLL, and MGE are all employees of Trovagene; FJ received research support from Biocartis, Transgenomic, and Trovagene.
©2014 American Association for Cancer Research.
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Source: PubMed