BRAF V600E mutations in urine and plasma cell-free DNA from patients with Erdheim-Chester disease.

Erdheim-Chester disease (ECD) is a rare histiocytosis with a high prevalence of BRAF V600E mutation (>50% of patients). Patients with BRAF-mutant ECD can respond to BRAF inhibitors. Unfortunately, the lack of adequate archival tissue often precludes BRAF testing. We hypothesized that cell-free DNA (cfDNA) from plasma or urine can offer an alternative source of biologic material for testing. We tested for BRAF V600E mutation in cfDNA from the plasma and urine of 6 ECD patients. In patients with available archival tissue, the result of BRAF mutation analysis was concordant with plasma and urine cfDNA results in all 3 patients (100% agreement, kappa 1.00). In all 6 patients, BRAF mutation analysis of plasma and urine cfDNA was concordant in 5 of 6 patients (83% agreement, kappa 0.67). Testing for BRAF V600E mutation in plasma and urine cfDNA should be further investigated as an alternative to archival tissue mutation analysis

Analytical validation of the Target Selector ctDNA platform featuring single copy detection sensitivity for clinically actionable EGFR, BRAF, and KRAS mutations.

BackgroundPersonalized medicine requires accurate molecular profiling for targeted therapy decisions. Insufficient tissue yield or tumor heterogeneity frequently limits the correct tissue biomarker determination. As a noninvasive complement to traditional tissue biopsies, liquid biopsies detect and track cancer driver mutations from biofluids (e.g., blood, urine). Here we present the analytical validation of Target Selector™ ctDNA assays capable of single mutant DNA copy detection.MethodsThe Target Selector ctDNA assay applies a patented Switch-Blocker technology to suppress amplification of background (wild-type) WT alleles, while allowing specific amplification of very low frequency mutant alleles. In contrast to allele specific enrichment technologies like ddPCR, one Switch-Blocker inhibits amplification of a DNA target up to 15 bp in length (e.g., one Switch-Blocker covers all KRAS exon 2, codon 12 and 13 variants). Target enrichment is achieved through a quantitative PCR reaction; subsequent DNA sequencing confirms mutation identity. Analytical validation with cancer cell line DNA was conducted by three independent operators using five instruments across five days.ResultsA total of 3086 samples were tested on EGFR, BRAF and KRAS Target Selector ctDNA assays, with EGFR WT as a reference. All assays showed >99% analytical sensitivity and specificity. Single mutant copy detection is confirmed by experimental data and theoretical estimates. In the presence of 14000 WT DNA copies, limits of detection were: EGFR Del19, 0.01%; EGFR L858R, 0.02%; EGFR T790M, 0.01%; BRAF V600E, 0.01%; KRAS G12C, 0.02%. Inter- and intra-assay analyses showed r2>0.94, suggesting consistent performance among operational variables. Healthy donor samples (100 tests) showed clinical specificity at >99%. Finally, Target Selector clinical experience data of >2200 patient samples is consistent with published tissue mutation prevalence.ConclusionsHighly sensitive Target Selector ctDNA assays with single mutant copy detection and limit of detection at 0.02% or better enable accurate molecular profiling vital for disease management

High-Risk Human Papillomavirus Detection in Urine Samples From a Referral Population With Cervical Biopsy-Proven High-Grade Lesions

The aim of the study was to evaluate the performance of the HPV-HR test to detect high-risk human papillomavirus (HPV) in urine samples in comparison with a commercial molecular HPV test.The aim of the study was to evaluate the performance of the HPV-HR test to detect high-risk human papillomavirus (HPV) in urine samples in comparison with a commercial molecular HPV test. Materials and Methods This is a prospective study, in which 350 patients diagnosed previously with cervical intraepithelial neoplasia (CIN) grade 2 or higher were enrolled. Urine and cervical specimens were collected. Urine was tested with the HPV-HR test and cervical specimens were tested with the Cobas. Results Of the 336 evaluable patients, there were 271 cases of CIN 2+, of which 202 were CIN 3+ and the remaining 65 patients were less than CIN 2. Positivity was 77.1% (95% confidence interval [CI] = 72.5–81.5) for the urine samples and 83.6% (95% CI = 79.6–87.6) for the cervical samples. Agreement between cervical and urine samples for HPV detection was 79.8% (κ = 0.363; 95% CI = 0.243–0.484). Sensitivity for CIN 2+ was 83.4% (95% CI = 78.4–87.6) for urine and 90.8% (95% CI = 86.7–92.9) for cervical samples. The sensitivity for CIN 3+ was 85.6% (95% CI = 80.0–90.2) for urine and 92.6% (95% CI = 88.0–95.8) for cervical samples. Specificity for worse than CIN 2 was 50.8% (95% CI = 33.7–59.0) and 46.2% (95% CI = 33.7–59.0) for urine and cervical samples, respectively. Conclusions Although these results demonstrated slightly higher detection rates for HR-HPV and clinical sensitivity in cervical samples than in urine, when compared with histological diagnoses, urine sampling is a viable alternative to access women who do not participate in routine screening programs.(undefined)info:eu-repo/semantics/publishedVersio