Project description:Recent advances in molecular technologies enable sensitive and quantitative assessment of circulating tumor DNA, offering a noninvasive disease monitoring tool for patients with malignant disorders. Here, we demonstrated on four follicular lymphoma cases that circulating tumor DNA based EZH2 mutation analysis performed by a highly sensitive droplet digital PCR method may be a valuable treatment monitoring approach in EZH2 mutant follicular lymphoma. EZH2 variant allele frequencies changed in parallel with the volume of metabolically active tumor sites observed on 18F-fluorodeoxyglucose positron emission tomography combined with computer tomography (PET-CT) scans. Variant allele frequencies of EZH2 mutations decreased or were eliminated rapidly upon successful treatment, with treatment failure being associated with elevated EZH2 variant allele frequencies. We also demonstrated spatial heterogeneity in a patient with two different EZH2 mutations in distinct anatomical sites, with both mutations simultaneously detected in the liquid biopsy specimen. In summary, circulating tumor DNA based EZH2 mutation analysis offers a rapid, real-time, radiation-free monitoring tool for sensitive detection of EZH2 mutations deriving from different anatomical sites in follicular lymphoma patients receiving immunochemotherapy.
Project description:Cancer cells are characterized by high genetic instability, that favors tumor relapse. The identification of the genetic causes of relapse can direct next-line therapeutic choices. As tumor tissue rebiopsy at disease progression is not always feasible, noninvasive alternative methods are being explored. Liquid biopsy is emerging as a non-invasive, easy and repeatable tool to identify specific molecular alterations and monitor disease response during treatment. The dynamic follow-up provided by this analysis can provide useful predictive information and allow prompt therapeutic actions, tailored to the genetic profile of the recurring disease, several months before radiographic relapse. Oncogenic fusion genes are particularly suited for this type of analysis. Anaplastic Lymphoma Kinase (ALK) is the dominant driver oncogene in several tumors, including Anaplastic Large-Cell Lymphoma (ALCL), Non-Small Cell Lung Cancer (NSCLC) and others. Here we review recent findings in liquid biopsy technologies, including ctDNA, CTCs, exosomes, and other markers that can be investigated from plasma samples, in ALK-positive cancers.
Project description:BackgroundDistinguishing between central nervous system lymphoma (CNSL) and CNS infectious and/or demyelinating diseases, although clinically important, is sometimes difficult even using imaging strategies and conventional cerebrospinal fluid (CSF) analyses. To determine whether detection of genetic mutations enables differentiation between these diseases and the early detection of CNSL, we performed mutational analysis using CSF liquid biopsy technique.MethodsIn this study, we extracted cell-free DNA from the CSF (CSF-cfDNA) of CNSL (N = 10), CNS infectious disease (N = 10), and demyelinating disease (N = 10) patients, and performed quantitative mutational analysis by droplet-digital PCR. Conventional analyses were also performed using peripheral blood and CSF to confirm the characteristics of each disease.ResultsBlood hemoglobin and albumin levels were significantly lower in CNSL than CNS infectious and demyelinating diseases, CSF cell counts were significantly higher in infectious diseases than CNSL and demyelinating diseases, and CSF-cfDNA concentrations were significantly higher in infectious diseases than CNSL and demyelinating diseases. Mutation analysis using CSF-cfDNA detected MYD88L265P and CD79Y196 mutations in 60% of CNSLs each, with either mutation detected in 80% of cases. Mutual existence of both mutations was identified in 40% of cases. These mutations were not detected in either infectious or demyelinating diseases, and the sensitivity and specificity of detecting either MYD88/CD79B mutations in CNSL were 80% and 100%, respectively. In the four cases biopsied, the median time from collecting CSF with the detected mutations to definitive diagnosis by conventional methods was 22.5 days (range, 18-93 days).ConclusionsThese results suggest that mutation analysis using CSF-cfDNA might be useful for differentiating CNSL from CNS infectious/demyelinating diseases and for early detection of CNSL, even in cases where brain biopsy is difficult to perform.
Project description:PurposeTo determine the feasibility of mRNAs (C-MYC, BCL-XL, BCL-6, NF-κβ, PTEN and AKT) in exosomes of plasma as a liquid biopsy method for monitoring and prognostic evolution in B-cell lymphomas.Patients and methodsExosomes were isolated from 98 patients with B-cell Lymphoma and 68 healthy controls. mRNAs were analyzed by quantitative PCR. An additional 31 post-treatment samples were also studied.ResultsIn the general and follicular lymphoma series, the presence of AKT mRNA was associated with poor response to rituximab-based treatment. Patients with first relapse or disease progression showed a lower percentage of PTEN and BCL-XL mRNA. The presence of BCL-6 mRNA was associated with a high death rate. The absence of PTEN mRNA in the general series, and presence of C-MYC mRNA in follicular lymphomas, were associated with short progression-free survival. BCL-6 and C-MYC mRNA were independent prognostic variables of overall survival. C-MYC mRNA may provide prognostic information with respect to overall survival. BCL-XL mRNA and increase of BCL-6 mRNA in post-treatment samples could serve as molecular monitoring markers.ConclusionsThis is the first large study to evaluate the prognostic and predictive values of pretreatment tumor-associated mRNA in exosomes. BCL-6 and C-MYC mRNA positivity in pretreatment samples were predictors of worse PFS compared to patients with mRNA negativity. C-MYC mRNA positivity was also a statistically significant predictor of inability to obtain complete response with first-line therapy.
Project description:Glioblastoma is the most common and malignant primary brain tumor. Despite a century of research efforts, the survival of patients has not significantly improved. Currently, diagnosis is based on neuroimaging techniques followed by histopathological and molecular analysis of resected or biopsied tissue. A recent paradigm shift in diagnostics ranks the molecular analysis of tissue samples as the new gold standard over classical histopathology, thus correlating better with the biological behavior of glioblastoma and clinical prediction, especially when a tumor lacks the typical hallmarks for glioblastoma. Liquid biopsy aims to detect and quantify tumor-derived content, such as nucleic acids (DNA/RNA), circulating tumor cells (CTCs), or extracellular vesicles (EVs) in biofluids, mainly blood, cerebrospinal fluid (CSF), or urine. Liquid biopsy has the potential to overcome the limitations of both neuroimaging and tissue-based methods to identify early recurrence and to differentiate tumor progression from pseudoprogression, without the risks of repeated surgical biopsies. This review highlights the origins and time-frame of liquid biopsy in glioblastoma and points to recent developments, limitations, and challenges of adding liquid biopsy to support the clinical management of glioblastoma patients.
Project description:Vitreoretinal lymphoma (VRL) is an uncommon eye malignancy, and VRLs of T cell origin are rare. They are difficult to treat, and their molecular underpinnings, including actionable genomic alterations, remain to be elucidated. At present, vitreous fluid liquid biopsies represent a valuable VRL sample for molecular analysis to study VRLs. In this study, we report the molecular diagnostic workup of a rare case of bilateral T cell VRL and characterize its genomic landscape, including identification of potentially targetable alterations. Using next-generation sequencing of vitreous-derived DNA with a pan-cancer 126-gene panel, we found a copy number gain of BRAF and copy number loss of tumor suppressor DNMT3A. To the best of our knowledge, this represents the first exploration of the T cell VRL cancer genome and supports vitreous liquid biopsy as a suitable approach for precision oncology treatments.
Project description:PurposeTo determine the diagnostic potential of next-generation sequencing (NGS) in vitreous samples, analyze genotype-phenotype characteristics, and compare NGS of matched vitreous and brain samples in patients with associated central nervous system lymphoma (CNSL).MethodsA total of 32 patients suspected of vitreoretinal lymphoma (VRL) who underwent diagnostic vitrectomy and NGS were included in this retrospective observational case-series. Fresh vitreous specimens from diagnostic vitrectomy of VRL-suspected patients underwent NGS using a custom panel targeting 747 candidate genes for lymphoma. They also underwent malignancy cytology, interleukin (IL)-10/IL-6, immunoglobulin heavy chain (IGH)/immunoglobulin kappa light chain (IGK) monoclonality testing. MYD88 L265P mutation was examined from anterior chamber tap samples. The diagnosis of VRL was made based on typical clinical characteristics for VRL, as well as malignant cytology, IGH/IGK clonality, or IL-10/IL-6 > 1. Sensitivity and specificity of NGS were compared with conventional diagnostic tests. Brain tissues suspected of lymphoma were collected by stereotactic biopsy and underwent NGS. Genetic variations detected in NGS of vitreous and brain tissue specimens were compared.ResultsThe sensitivity values for cytology, IL-10/IL-6 > 1, clonality assays for IGH and IGK, MYD88 L265P detection in anterior chamber tap samples, and vitreous NGS were 0.23, 0.83, 0.68, 0.79, 0.67, and 0.85, with specificity values of 1.00, 0.83, 0.50, 0.25, 0.83, and 0.83, respectively. The sensitivity (0.85) of vitreous NGS was the highest compared to other conventional diagnostic tests for VRL. The most common mutations were MYD88 (91%), CDKN2A (36%), PIM1 (32%), IGLL5 (27%), and ETV6 (23%). Although several gene alterations demonstrated heterogeneity between the brain and eyes, some common mutational profiles were observed in matched vitreous and brain samples.ConclusionsOverall, NGS of the vitreous demonstrated high sensitivity among conventional diagnostic tests. VRL and CNSL appeared to have both shared and distinct genetic variations, which may suggest site-specific variations from a common origin.
Project description:PurposeTo seek novel diagnostic approaches, we improved the workflow of cell-free DNA (cfDNA) sequencing and evaluated its feasibility in vitreoretinal lymphoma (VRL) specimens; the profile of mutations was preliminarily analyzed for potential diagnostic value.MethodsThe study was a diagnostic trial. 23 eyes of 23 patients with VRL and 25 eyes of 25 patients with inflammatory eye diseases were enrolled. Approximate 500μl undiluted vitreous humor and 10ml diluted vitreous fluid was obtained through diagnostic vitrectomy and sent for cytopathological examinations. 500μl of the diluted vitreous fluid was spared for cfDNA sequencing. For cfDNA sequencing, DNA fragmentation procedure was added to the workflow to improve the extraction efficiency; mutations detected were analyzed for potential diagnostic model. The sensitivity and specificity of the cytopathology and cfDNA sequencing were compared. The clinical manifestations were preliminarily analyzed for potential correlations with the genotypes.ResultsCfDNA sequencing was accomplished in 23 eyes with VRL and 20 eyes with inflammatory eye diseases. VRL-related mutated genes included MYD88 (18 eyes, 78%), ETV6 (11 eyes, 48%), PIM1 (11 eyes,48%), BTG2 (7 eyes, 30%), IRF4 (7 eyes, 30%), CD79B (6 eyes, 26%), LRP1B (6 eyes, 26%), etc. Logistic regression based on the mutations of MYD88 and ETV6 was of the potential for the diagnosis of VRL (P<0.001, adjusted R2 = 0.789, sensitivity 0.913, specificity 0.950); by comparison, the sensitivity and specificity of the vitreous cytopathology were 0.826 and 1.000, respectively. Further analysis of the mutation profile showed that patients carrying CD79B mutation tended to have higher intraocular interleukin-10 level (P=0.030), that CARD11 mutation was correlated with younger age at ocular onset (P=0.039), and that patients with intracranial involvement carried more multiple-site mutations in the BTG2 gene (P=0.013).ConclusionsThe improved workflow of CfDNA sequencing is of sound feasibility in a limited amount of vitreous humor. The logistic model based on the mutations could help to provide reliable clues for the diagnosis of VRL.
Project description:Background Tyrosine kinase inhibitors (TKIs) significantly improve clinical outcomes in patients with non-small cell lung cancer due to anaplastic lymphoma kinase (ALK) gene rearrangement. However, the rate of relapse with TKIs is high owing to the development of resistance mutations during treatment. Repeated biopsies during disease progression are crucial for elucidating the molecular mechanisms underlying the development of resistance to ALK inhibitors. Analysis of cell-free DNA (cfDNA) obtained from plasma is a novel approach for tumor genotyping. Methods In this mixed prospective and retrospective observational cohort study, we investigated the clinical feasibility of continuous quantitative monitoring of ALK-acquired mutations in plasma obtained from patients with ALK+ non-small cell lung cancer by using a highly sensitive and specific droplet digital polymerase chain reaction (ddPCR) assay. We enrolled nine patients, including three treatment-naïve patients recently diagnosed with ALK+ non-small cell lung cancer via tissue biopsy and expected to receive ALK TKIs and six patients already receiving ALK TKIs. Plasma samples were collected from these patients every 3 months. cfDNA was extracted from 66 samples during the study period, and 10 ALK mutations were simultaneously evaluated. Results The numbers of samples showing the G1202R, C1156Y, G1269A, F1174L, T1151ins, and I1171T mutations were 32, 16, 5, 4, 1, and 1, respectively. The L1196M, L1152R, V1180L, and S1206Y mutations were not detected. Correlation analyses between progression-free survival and the time from treatment initiation (or treatment modification) to the detection of resistance mutations revealed that although resistance mutations may occur before a drug change becomes necessary, there is a duration during which the disease does not progress. Conclusions Our findings suggest that real-time quantitative monitoring of ALK resistance mutations during the response period could provide a time course of changes while acquiring resistance mutations. This information would be beneficial for designing an appropriate treatment strategy.