A pilot study evaluating concordance between blood-based and patient-matched tumor molecular testing within pancreatic cancer patients participating in the Know Your Tumor (KYT) initiative (original) (raw)

Profiling tumour heterogeneity through circulating tumour DNA in patients with pancreatic cancer

Oncotarget

The majority of pancreatic ductal adenocarcinomas (PDAC) are diagnosed late so that surgery is rarely curative. Earlier detection could significantly increase the likelihood of successful treatment and improve survival. The aim of the study was to provide proof of principle that point mutations in key cancer genes can be identified by sequencing circulating free DNA (cfDNA) and that this could be used to detect early PDACs and potentially, premalignant lesions, to help target early effective treatment. Targeted next generation sequencing (tNGS) analysis of mutation hotspots in 50 cancer genes was conducted in 26 patients with PDAC, 14 patients with chronic pancreatitis (CP) and 12 healthy controls with KRAS status validated by digital droplet PCR. A higher median level of total cfDNA was observed in patients with PDAC (585 ng/ml) compared to either patients with CP (300 ng/ml) or healthy controls (175 ng/ml). PDAC tissue showed wide mutational heterogeneity, whereas KRAS was the most commonly mutated gene in cfDNA of patients with PDAC and was significantly associated with a poor disease specific survival (p=0.018). This study demonstrates that tNGS of cfDNA is feasible to characterise the circulating genomic profile in PDAC and that driver mutations in KRAS have prognostic value but cannot currently be used to detect early emergence of disease. Importantly, monitoring total cfDNA levels may have utility in individuals "at risk" and warrants further investigation.

Circulating Tumor DNA-Based Testing and Actionable Findings in Patients with Advanced and Metastatic Pancreatic Adenocarcinoma

The Oncologist, 2021

Purpose Recent advances in molecular diagnostic technologies allow for the evaluation of solid tumor malignancies through noninvasive blood sampling, including circulating tumor DNA profiling (ctDNA). Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis, often because of late presentation of disease. Diagnosis is often made using endoscopic ultrasound or endoscopic retrograde cholangiopancreatography, which often does not yield enough tissue for next-generation sequencing. With this study, we sought to characterize the ctDNA genomic alteration landscape in patients with advanced PDAC with a focus on actionable findings. Materials and Methods From December 2014 through October 2019, 357 samples collected from 282 patients with PDAC at Mayo Clinic underwent ctDNA testing using a clinically available assay. The majority of samples were tested using the 73-gene panel which includes somatic genomic targets, including complete or critical exon coverage in 30 and 40 genes, respecti...

Plasma Circulating Tumor DNA in Pancreatic Cancer Patients Is a Prognostic Marker

Clinical Cancer Research, 2016

Purpose: Despite recent therapeutic advances, prognosis of patients with pancreatic adenocarcinoma remains poor. Analyses from tumor tissues present limitations; identification of informative marker from blood might be a promising alternative. The aim of this study was to assess the feasibility and the prognostic value of circulating tumor DNA (ctDNA) in pancreatic adenocarcinoma. Experimental Design: From 2011 to 2015, blood samples were prospectively collected from all consecutive patients with pancreatic adenocarcinoma treated in our center. Identification of ctDNA was done with next-generation sequencing targeted on referenced mutations in pancreatic adenocarcinoma and with picoliter droplet digital PCR. Results: A total of 135 patients with resectable (n = 31; 23%), locally advanced (n = 36; 27%), or metastatic (n = 68; 50%) pancreatic adenocarcinoma were included. In patients with advanced pancreatic adenocarcinoma (n = 104), 48% (n = 50) had ctDNA detectable with a median mut...

Circulating Tumor DNA as a Clinical Test in Resected Pancreatic Cancer

Clinical Cancer Research, 2019

Purpose: In research settings, circulating tumor DNA (ctDNA) shows promise as a tumor-specific biomarker for pancreatic ductal adenocarcinoma (PDAC). This study aims to perform analytical and clinical validation of a KRAS ctDNA assay in a Clinical Laboratory Improvement Amendments (CLIA) and College of American Pathology–certified clinical laboratory. Experimental Design: Digital-droplet PCR was used to detect the major PDAC-associated somatic KRAS mutations (G12D, G12V, G12R, and Q61H) in liquid biopsies. For clinical validation, 290 preoperative and longitudinal postoperative plasma samples were collected from 59 patients with PDAC. The utility of ctDNA status to predict PDAC recurrence during follow-up was assessed. Results: ctDNA was detected preoperatively in 29 (49%) patients and was an independent predictor of decreased recurrence-free survival (RFS) and overall survival (OS). Patients who had neoadjuvant chemotherapy were less likely to have preoperative ctDNA than were chem...

Circulating tumor cells (Ctc) and kras mutant circulating free Dna (cfdna) detection in peripheral blood as biomarkers in patients diagnosed with exocrine pancreatic cancer

BMC cancer, 2015

Pancreatic cancer remains one of the most difficult cancers to treat with the poorest prognosis. The key to improving survival rates in this disease is early detection and monitoring of disseminated and residual disease. However, this is hindered due to lack reliable diagnostic and predictive markers which mean that the majority of patients succumb to their condition within a few months. We present a pilot study of the detection circulating free DNA (cfDNA) combined with tumor specific mutation detection by digital PCR as a novel minimally invasive biomarker in pancreatic ductal adenocarcinoma (PDAC). This was compared to the detection of CTC by the CellSearch® system and a novel CTC enrichment strategy based on CD45 positive cell depletion. The aim of the study was to assess tumor specific DNA detection in plasma and CTC detection as prognostic markers in PDAC. We detected KRAS mutant cfDNA in 26 % of patients of all stages and this correlated strongly with Overall Survival (OS), 6...

Genomic testing for pancreatic cancer in clinical practice as real-world evidence

Pancreatology : official journal of the International Association of Pancreatology (IAP) ... [et al.], 2018

Precision medicine guided by comprehensive genome sequencing represents a potential treatment strategy for pancreatic cancer. However, clinical sequencing for pancreatic cancer entails several practical difficulties. We have launched an in-house clinical sequencing system and started genomic testing for patients with cancer in clinical practice. We have analyzed the clinical utility of this system in pancreatic cancer. We retrospectively reviewed 20 patients with pancreatic cancer who visited our division. Genomic DNA was extracted from both tumor tissue and peripheral blood mononuclear cells obtained from the patients. We performed a comprehensive genomic testing using targeted amplicon sequencing for 160 cancer-related genes. The primary endpoints were the detection rates of potential actionable and druggable gene alterations. The secondary endpoints were the detection rate of secondary germline findings, the rate of re-biopsy required for genome sequencing, survival time after th...

Combined circulating tumor DNA and protein biomarker-based liquid biopsy for the earlier detection of pancreatic cancers

Proceedings of the National Academy of Sciences

The earlier diagnosis of cancer is one of the keys to reducing cancer deaths in the future. Here we describe our efforts to develop a noninvasive blood test for the detection of pancreatic ductal adenocarcinoma. We combined blood tests forKRASgene mutations with carefully thresholded protein biomarkers to determine whether the combination of these markers was superior to any single marker. The cohort tested included 221 patients with resectable pancreatic ductal adenocarcinomas and 182 control patients without known cancer.KRASmutations were detected in the plasma of 66 patients (30%), and every mutation found in the plasma was identical to that subsequently found in the patient’s primary tumor (100% concordance). The use ofKRASin conjunction with four thresholded protein biomarkers increased the sensitivity to 64%. Only one of the 182 plasma samples from the control cohort was positive for any of the DNA or protein biomarkers (99.5% specificity). This combinatorial approach may pro...

Analysis of circulating cell-free DNA identifies KRAS copy number gain and mutation as a novel prognostic marker in Pancreatic cancer

Scientific Reports

Serial biopsy of pancreatic ductal adenocarcinoma (pDAc), to chart tumour evolution presents a significant challenge. We examined the utility of circulating free DNA (cfDNA) as a minimally invasive approach across a cohort of 55 treatment-naïve patients with PDAC; 31 with metastatic and 24 with locally advanced disease. Somatic mutations in cfDNA were detected using next generation sequencing in 15/24 (62.5%) and 27/31 (87%) of patients with locally advanced and metastatic disease, respectively. Copy number changes were detected in cfDNA of 10 patients of whom 7 exhibited gain of chromosome 12p harbouring KRAS as well as a canonical KRAS codon 12 mutation. In multivariable Cox Regression analysis, we show for the first time that patients with KRAS copy number gain and KRAS mutation have significantly worse outcomes, suggesting that this may be linked to PDAC progression. The simple cfDnA assay we describe will enable determination of the presence of KRAS copy number gain and KRAS mutations in larger studies and clinical trials.

Digital next‐generation sequencing of cell‐free DNA for pancreatic cancer

JGH Open, 2021

Background and Aim: The clinical applicability of digital next-generation sequencing (dNGS), which eliminates polymerase chain reaction (PCR) and sequencing errorderived noise by using molecular barcodes (MBs), has not been fully evaluated. We evaluated the utility of dNGS of cell-free DNA (cfDNA) in liquid biopsies obtained from patients with pancreatic cancer. Methods: Fifty-eight patients with pancreatic cancer undergoing endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) were included. Samples were subjected to sequencing of 50 cancer-related genes using next-generation sequencing (NGS). The results were used as reference gene alterations. NGS of cfDNA from plasma was performed for patients with a mutant allele frequency (MAF) >1% and an absolute mutant number > 10 copies/plasma mL in KRAS or GNAS by digital PCR. Sequence readings with and without MBs were compared with reference to EUS-FNA-derived gene alterations. Results: The concordance rate between dNGS of cfDNA and EUS-FNA-derived gene alterations was higher with than without MBs (p = 0.039), and MAF cutoff values in dNGS could be decreased to 0.2%. dNGS using MBs eliminated PCR and sequencing error by 74% and 68% for TP53 and all genes, respectively. Overall, dNGS detected mutations in KRAS (45%) and TP53 (26%) and copy number alterations in CCND2, CCND3, CDK4, FGFR1, and MYC, which are targets of molecular-targeted drugs. Conclusions: dNGS of cfDNA using MBs is useful for accurate detection of gene alterations even with low levels of MAFs. These results may be used to inform the development of diagnostics and therapeutics that can improve the prognosis of pancreatic cancer.

Overcoming diagnostic issues in precision treatment of pancreatic cancer

Expert Review of Precision Medicine and Drug Development, 2018

Introduction: With high-throughput DNA analysis with next-generation sequencing (NGS), a new area of comprehensive molecular diagnostics is entering clinic. The profile of biomarkers (mutations and other abnormalities) may lay the foundation for precision treatment. Pancreatic ductal adenocarcinoma (PDAC) represents a challenge with its many aberrations spread over all pathways. Furthermore, suitable samples for molecular diagnostics are difficult to obtain, both for tissue-based (biopsy, cytology) and blood-based (cell-free DNA and circulating tumor cells [CTC]) assays. Areas covered: Biomarkers, material, methods, and management of biomarkers for PDAC in precision treatment. Biomarkers refer multiple biomarkers at the same time. Material refers to the different biological sources including blood-based approaches with CTCs. Methods cover the analysis techniques such as NGS and RNA sequencing. Management comprises the handling of NGS and data analysis, as well as the need for clinically applicable, evidence-based recommendations. Expert commentary: Outstanding problems are the procurement of samples suitable for multiplex biomarker analysis such as NGS. This may be overcome by single-cell sequencing. The final challenge, common to all approaches beyond a limited panel of genes, will be the holistic, evidence-based analysis of NGS data for making clinically relevant treatment recommendations. Outcome studies including costeffectiveness are pivotal prior to reimbursement.