Disease Monitoring In Patients Research Articles

Abstract 2497: Extracellular vesicle based ALPPL2 and THBS2 as biomarkers for disease monitoring in patients with pancreatic ductal adenocarcinoma

Abstract Pancreatic ductal adenocarcinoma (PDAC) remains a formidable challenge in the realm of oncology, characterized by its aggressive nature and resistance to treatment. Several therapeutic regimens have been shown to extend patient survival, but the majority of the patients become refractory to the treatments in a short period of time. Hence, it is critical to monitor a patient’s response to treatment in a timely manner so that different treatment regimens can be considered promptly. Currently, CA19-9 is the most common blood-based marker being used to monitor disease burden in patients with PDAC. However, 15-20% of patients with PDAC do not have elevated blood CA19-9 levels. In this study, we sought to determine the utility of two circulating extracellular vesicle (EV) based protein biomarkers, ALPPL2 (Alkaline phosphatase, placental-like 2) and THBS2 (Thrombospondin 2), for disease monitoring in patients with PDAC. We first established and optimized EV assays using the ExoViewTM platform for detecting and quantifying the number of ALPPL2+ or THBS2+ EVs in serum samples. We then determined the concentrations of ALPPL2+ or THBS2+ EVs in samples from healthy individuals and longitudinal samples from patients with Stage IV PDAC undergone treatment. The longitudinal samples were from 26 patients of which 16 were CA19-9 secretors (defined as >35 U/ml) and 10 were CA19-9 non-secretors (defined as <35 U/ml) that were treated with various regimens for 4-24 months with monthly blood sample collection and CT scans (a total of 305 samples). We found that the concentrations of ALPPL2+ and THBS2+ EVs are on average 1,737 and 1,113 times higher in PDAC patients than in the healthy controls, respectively. Correlation analysis using the mixed linear model showed that the concentrations of both ALPPL2+ and THBS2+ EVs significantly correlate with changes in tumor size (based on RECIST measurements) in the longitudinal samples of CA19-9 non-secretors or secretors. In CA19-9 non-secretors the correlation p values are 0.003 and 0.006 for ALPPL2+ and THBS2+ EVs, respectively, whereas in CA19-9 secretors, the p values are 0.014 and 0.016 for ALPPL2+ and THBS2+ EVs, respectively. Our data indicates that EV based ALPPL2 and THBS2 could potentially serve as biomarkers for disease monitoring in patients with PDAC. (This work was supported in part by the Dorrance Family Fund and the Flinn Foundation) Citation Format: Kuntal Halder, Gayle Jameson, Erkut Borazanci, Wei Lin, Dereck Cridebring, Daniel Von Hoff, Haiyong Han. Extracellular vesicle based ALPPL2 and THBS2 as biomarkers for disease monitoring in patients with pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2497.

Genome-wide repeat landscapes in cancer and cell-free DNA.

Genetic changes in repetitive sequences are a hallmark of cancer and other diseases, but characterizing these has been challenging using standard sequencing approaches. We developed a de novo kmer finding approach, called ARTEMIS (Analysis of RepeaT EleMents in dISease), to identify repeat elements from whole-genome sequencing. Using this method, we analyzed 1.2 billion kmers in 2837 tissue and plasma samples from 1975 patients, including those with lung, breast, colorectal, ovarian, liver, gastric, head and neck, bladder, cervical, thyroid, or prostate cancer. We identified tumor-specific changes in these patients in 1280 repeat element types from the LINE, SINE, LTR, transposable element, and human satellite families. These included changes to known repeats and 820 elements that were not previously known to be altered in human cancer. Repeat elements were enriched in regions of driver genes, and their representation was altered by structural changes and epigenetic states. Machine learning analyses of genome-wide repeat landscapes and fragmentation profiles in cfDNA detected patients with early-stage lung or liver cancer in cross-validated and externally validated cohorts. In addition, these repeat landscapes could be used to noninvasively identify the tissue of origin of tumors. These analyses reveal widespread changes in repeat landscapes of human cancers and provide an approach for their detection and characterization that could benefit early detection and disease monitoring of patients with cancer.

Utility of circulating tumor DNA (ctDNA) as a predictive biomarker for disease monitoring in patients with non-seminomatous germ-cell tumor (NSGCT).

Utility of circulating tumor DNA (ctDNA) as a predictive biomarker for disease monitoring in patients with non-seminomatous germ-cell tumor (NSGCT).

Longitudinal Changes of Retinal Structure in Molecularly Confirmed C1QTNF5 Patients With Late-Onset Retinal Degeneration.

The purpose of this study was to present our findings on the natural history of late-onset retinal degeneration (LORD) in patients with molecularly confirmed C1QTNF5 heterozygous pathogenic variants and assess suitability of retinal structure parameters for disease monitoring. Sixteen patients with C1QTNF5-LORD were retrospectively identified from Moorfields Eye Hospital, UK. Fundus autofluorescence (FAF), optical coherence tomography (OCT) scans, and best-corrected visual acuity (BCVA) were collected. Area of atrophy (AA) was manually drawn in FAF images. Ellipsoid zone (EZ) width and foveal retinal thickness of the whole retina and outer retina were extracted from OCT scans. Age-related changes were tested with linear-mixed models. Patients had median age of 62.3years (interquartile range [IQR]=58.8-65.4years) at baseline, and median follow-up of 5.1years (IQR=2.6-7.6years). AA, EZ width, and retinal thickness parameters remained unchanged until age 50years, but showed significant change with age thereafter (all P < 0.0001). AA and EZ width progressed rapidly (dynamic range normalized rates=4.3-4.5%/year) from age 53.9 and 50.8years (estimated inflection points), respectively. Retinal thickness parameters showed slower progression rates (range=1.6-2.5%/year) from age 60 to 62.3. BCVA (median=0.3 LogMAR, IQR=0.0-1.0 at baseline) showed a rapid decline (3.3%) from age 70years. Findings from patients with earlier disease showed FAF atrophy manifests in the temporal retina initially, and then progresses nasally. Patients with LORD remained asymptomatic until age 50years, before suffering rapid outer retinal degeneration. EZ width and AA showed rapid progression and high interocular correlation, representing promising outcome metrics. Clinical measures also capturing the temporal retina may be preferable, enabling earlier detection and better disease monitoring. Area of atrophy in FAF images and OCT-measured EZ width represent promising outcome metrics for disease monitoring in patients with C1QTNF5-LORD.

Disease Monitoring in Acute Myeloid Leukemia with CLEC2A qRT-PCR

CLEC2A, C-Type Lectin Domain Family 2 Member A, is a newly discovered AML-restricted antigen. Detailed characteristics, clinical correlations, and therapeutic potential of CLEC2A in AML is presented by Kirkey et. Al. (ASH 2023). CLEC2A is entirely silent in normal hematopoiesis and uniquely expressed in patients with KMT2A rearrangements, providing an ideal therapeutic target in this high-risk subtype of AML. To date, CLEC2A has not been implicated in hematologic malignancies and expression of CLEC2A is entirely absent from normal tissues other than minimal expression in the skin. In addition to its utility as a therapeutic target, CLEC2A provides a unique target for disease monitoring given its lack of expression in normal hematopoietic cells. Here we present a highly sensitive quantitative molecular assay for CLEC2A, establishing its utility for disease monitoring in patients with KMT2A-r AML. In our efforts to evaluate CLEC2A expression and demonstrate the utility of using CLEC2A for disease monitoring in KMT2A-r, we developed a qRT-PCR assay using probes directed at exon 3 of the CLEC2A gene. The assay was optimized with RNA from the OCI-AML2 cells, validated to be CLEC2A-positive by flow cytometry and RNA from Kasumi-1 and K562 cells, both CLEC2A-negative by flow cytometry. We established the sensitivity of the assay through serial dilution of OCI-AML2 in a background of CLEC2A-negative Kasumi-1 or K562 cell RNA with concentrations ranging from 100% to 0.0001% OCI-AML2 RNA. The sensitivity assay demonstrated CLEC2A was detected at a level of 0.001% in both Kasumi-1 and K562. Given the association of CLEC2A with KMT2A-r AML, we evaluated the prevalence of CLEC2A as assessed by qRT-PCR. We screened diagnostic specimens from a large cohort of patients enrolled on recent COG Phase III clinical trials (ages 0-29) with and without KMT2A fusions to establish prevalence of CLEC2A expression. Using our CLEC2A qRT-PCR assay we evaluated diagnostic specimens from 122 patients with (N=76) and without (N=46) KMT2A-r, in addition to RNA from 8 normal bone marrow (NBM) samples, as controls and validated CLEC2A was entirely absent in NBM with median expression 0.13 copies per 1e 4 GUSB, figure 1A. Of evaluable samples, CLEC2A was detected in 65 of 76 (85%) KMT2A-r cases with a median expression of 317.45 copies per 1e 4 GUSB (range 0.03 - 21134.21 copies per 1e 4 GUSB). CLEC2A was detected in 21 of 46 (45%) non-KMT2A-r cases tested with a median expression of 1.37 copies per 1e 4 GUSB (range 0 - 1204.84 copies per 1e 4 GUSB). Further evaluation of KMT2A fusion partner showed that CLEC2A was detected in 100% of MLLT4 (N=6/6), 83.3% in MLLT10 (N=20/24), 72.7% of ELL (N=8/11), and 42.9% in MLLT3 (N=21/49). While CLEC2A expression was seen in both KMT2A-r and non-KMT2A-r AML patients, CLEC2A levels were significantly higher in KMT2A-r patients compared to non-KMT2A-r and NBM samples (p &amp;lt; 0.0001). Since CLEC2A is expressed in AML with no expression in normal hematopoietic cells, we hypothesized that monitoring CLEC2A via qRT-PCR throughout treatment (i.e., at diagnosis, at end of induction [EOI], at relapse) would provide added specificity to traditional flow cytometric disease monitoring. Using paired RNA samples from patients across multiple timepoints, we evaluated the change in CLEC2A expression throughout treatment, figure 1B. Patients with high CLEC2A expression at diagnosis (mean 1670 copies per 1e 4 GUSB, n=39) had decreased expression at EOI (mean 199 copies per 1e 4 GUSB, n=45) indicating treatment response, however high CLEC2A expression was seen at time of relapse (mean 1849 copies per 1e 4 GUSB, n=13) with CLEC2A expression preserved at relapse for all patients. qRT-PCR was able to detect CLEC2A expression in 7 patients at EOI who were in a morphologic CR with 6/7 (86%) patients being MRD-negative, further highlighting the increased sensitivity of CLEC2A qRT-PCR. Here we describe qRT-PCR monitoring of CLEC2A, a novel AML-restricted antigen highly enriched in KMT2A-r AML, provides added specificity and sensitivity to traditional flow cytometric MRD analysis. CLEC2A monitoring via qRT-PCR can be used to assess disease response throughout treatment and evaluate impending relapse as CLEC2A expression is retained at relapse. Additionally, qRT-PCR monitoring of CLEC2A can be incorporated in to pre- and post-HSCT disease evaluations similarly to qRT-PCR analysis of other known high-risk fusions such as NUP98-NSD1 fusions.

Measurable residual disease monitoring in patients with acute myeloid leukemia treated with lower-intensity therapy: Roadmap from an ELN-DAVID expert panel.

With the availability of effective targeted agents, significant changes have occurred in the management of patients with acute myeloid leukemia (AML) over the past several years, particularly for those considered unfit for intensive chemotherapy. While testing for measurable residual disease (MRD) is now routinely performed in patients treated with intensive chemotherapy to refine prognosis and, possibly, inform treatment decision-making, its value in the context of lower-intensity regimens is unclear. As such regimens have gained in popularity and can be associated with higher response rates, the need to better define the role of MRD assessment and the appropriate time points and assays used for this purpose has increased. This report outlines a roadmap for MRD testing in patients with AML treated with lower-intensity regimens. Experts from the European LeukemiaNet (ELN)-DAVID AML MRD working group reviewed all available data to propose a framework for MRD testing in future trials and clinical practice. A Delphi poll served to optimize consensus. Establishment of uniform standards for MRD assessments in lower-intensity regimens used in treating patients with AML is clinically relevant and important for optimizing testing and, ultimately, improving treatment outcomes of these patients.

P-085 The use of clonotypic mass spectrometry for post-AHCT blood-based measurable residual disease monitoring in patients with light chain multiple myeloma

P-085 The use of clonotypic mass spectrometry for post-AHCT blood-based measurable residual disease monitoring in patients with light chain multiple myeloma

Utility of circulating tumor DNA (ctDNA) as a predictive biomarker for disease monitoring in patients (pts) with cholangiocarcinoma (CCA) before and during adjuvant chemotherapy (ACT): Sub-analysis of the randomized phase 2 STAMP trial.

4123 Background: Detection of circulating tumor DNA (ctDNA) in blood is a powerful predictive biomarker for identifying molecular residual disease (MRD) post-surgery. Not much is known about the utility of identifying MRD using ctDNA in pts with resected CCA, despite its associated poor prognosis. The STAMP trial (NCT03079427), a randomized phase 2 study comparing adjuvant capecitabine (CAP) to gemcitabine plus cisplatin (GemCis) showed no difference in recurrence-free survival (RFS) and overall survival (OS) between the 2 arms. The goal of this analysis was to evaluate the feasibility of monitoring ctDNA to predict the risk of recurrence in pts with resected CCA. Methods: A total of 254 plasma samples were collected from a cohort of 89 CCA (hilar, N = 43; distal, N = 46) pts post-surgery at 3 separate time points; pre-ACT (baseline, N = 89), on-ACT C5D1 (after 5 cycles of treatment) (N = 88), and on-ACT C8D1 (after 8 cycles of treatment) (N = 77). Longitudinal ctDNA testing was performed using a personalized, tumor-informed ctDNA assay (Signatera, bespoke mPCR-NGS assay). ctDNA results were analyzed and evaluated for its correlation with RFS and OS. Results: At the MRD timepoint (baseline, pre-ACT), 24.7% (22/89) pts were ctDNA-positive, 90.9% (20/22) of whom recurred demonstrating a trend for shorter RFS (HR = 1.7, 95%Cl 0.98-2.8, p = 0.069) compared to ctDNA-negative pts. All pts who remained ctDNA-positive on-ACT at C5D1 (N = 17) and C8D1 (N = 15), recurred clinically with a significantly shorter RFS (HR = 8.1, 95%Cl 4.3-15, p &lt; 0.0001 and HR = 5.0, 95%Cl 2.7-9.4, p &lt; 0.0001, respectively). The primary cancer site (hilar vs distal) or type of ACT (CAP vs GemCis) had no impact on RFS irrespective of ct-DNA result. Pts who remained ctDNA-negative on ACT (N = 56) showed significantly better RFS compared to pts who remained positive (N = 10, HR = 6.6, 95%Cl 3.1-14, p &lt; 0.001), or who turned positive (N = 11, HR = 5.2, 95%Cl 2.54-10.5, p &lt; 0.001). In multivariate analysis including primary tumor site, sex, pathological grade and ACT regimen, positive ctDNA status at baseline (pre-ACT) remained significant for poor RFS (HR = 1.82, 95%CI 1.04-3.18, p = 0.035). Conclusions: Personalized monitoring of ctDNA both pre and on-ACT is feasible and predictive for recurrence in pts with resected CCA. To our best knowledge, this is one of the first reports presenting the clinical implication of ctDNA monitoring on ACT, in pts with CCA. Our findings suggest ctDNA monitoring may help optimize clinical decision-making in pts with resected CCA. Larger prospective studies would be needed to validate the findings of this study. Clinical trial information: NCT03079427 .

Minimal/Measurable Residual Disease Monitoring in Patients with Lymphoid Neoplasms by High-Throughput Sequencing of the T-Cell Receptor

High-throughput sequencing of the T-cell receptor beta (TRB) and gamma (TRG) loci is increasingly utilized due to its high sensitivity, specificity, and versatility in the diagnosis of various T-cell malignancies. Application of these technologies for tracking disease burden can be valuable in detecting recurrence, determining response to therapy, guiding future management of patients, and establishing endpoints for clinical trials. In this study, the performance of the commercially available LymphoTrack high-throughput sequencing assay was assessed for determining residual disease burden in patients with various T-cell malignancies. A custom bioinformatics pipeline and database was also developed to facilitate minimal/measurable residual disease analysis and clinical reporting. This assay demonstrated excellent test performance characteristics, achieving a sensitivity of 1 of 100,000 T-cell equivalents for the DNA inputs evaluated and high concordance with orthogonal testing methods. This assay was further utilized to correlate disease burden in several patients, demonstrating its potential utility for monitoring patients with T-cell malignancies.

Utility of circulating tumor DNA in monitoring treatment response to immune checkpoint inhibitors in patients with advanced genitourinary cancers.

721 Background: Current methodologies for monitoring treatment response are largely based on conventional scans and/or tumor biopsies, which may be limited in their ability to accurately assess disease burden at the molecular level. Circulating tumor DNA (ctDNA) detection in blood has emerged as a prognostic and predictive biomarker and has shown to better assess treatment response in patients receiving immune checkpoint inhibitors (ICI). We conducted a prospective, pilot study to investigate the concordance of serial ctDNA detection and dynamics with radiographic response in patients with advanced GU malignancies undergoing ICI-based treatment. Methods: Twenty patients with histologically confirmed advanced GU malignancies (renal, urothelial, and prostate) were enrolled in the prospective study. All eligible patients received ICI treatment for at least 12 weeks and were followed by serial collection of blood samples every 6-8 weeks until disease progression. Conventional scans were performed approximately every 12 weeks until disease progression. Overall response rate (ORR) by investigator was reported and associated with ctDNA detection. Results: ctDNA analysis was performed on 122 plasma samples obtained from 20 patients (N=15 renal cell carcinoma; N=4 urothelial carcinoma; N=1 prostate cancer). Prior therapies to ICI-based treatment included chemotherapy (10%), hormonal therapy (5%) and anti-VEGF (5%). After study enrollment, patients received anti-PD-1 (95%), anti-CTLA-4 (30%) or anti-PD-L1 (5%) with an ORR of 70% as best response. With a median follow-up of 19 months (range: 4-48), progressive disease was observed in 7 patients. Nineteen patients had longitudinal plasma samples available and ctDNA detection at any time point was 45% (9/20). The overall concordance between ctDNA dynamics and radiographic response at 12 weeks was observed in 89% (17/19) of patients. Of these 17 concordant patients, one patient showed transient ctDNA positivity followed by clearance at the last two timepoints on treatment. The two patients with discordant results included the ones with CNS-only metastasis (ctDNA negative). Of the 7 patients who progressed on ICI, ctDNA was detected in five (71%); the remaining two had CNS-only metastases. The last patient had a single time point available on treatment that showed ctDNA-positivity and passed away 7 weeks after molecular evidence of disease. Conclusions: In this study, serial collection of blood samples for ctDNA analysis to monitor response to ICI-based therapiesin patients with advanced GU tumors was feasible. There was a high concordance rate between radiological imaging and ctDNA data, especially in extra-CNS disease. Further studies are needed to validate ctDNA as a tool to aid disease monitoring in patients treated with ICI.

Potential Role of Tumor-Derived Exosomes in Non-Small-Cell Lung Cancer in the Era of Immunotherapy.

Lung cancer, of which non-small-cell lung cancer (NSCLC) represents about 80% of all cases, is the second most common cancer diagnosed in the general population and one of the major causes of cancer-related deaths worldwide. Overall, the outcomes of patients with advanced NSCLC are still disappointing despite advances in diagnosis and treatment. In recent years immune-checkpoint inhibitors (ICIs), administered alone or in combination with chemotherapy, have revolutionized the treatment landscape of patients with advanced non-small-cell lung cancer. However, until now, tissue expression of PD-L1 and tumor mutation burden represent the only available biomarkers for NSCLC patients treated with ICIs. A growing body of evidence showed that tumor-derived exosomes (TDEs) have the PD-L1 protein on their surface and that they are involved in angiogenesis, tumor growth, invasion, metastasis and immune escape. This review focused on the potential clinical applications of TDEs in NSCLC, including their possible role as a biomarker for prognosis and disease monitoring in patients undergoing immunotherapy.

Extracellular vesicle DNA from human melanoma tissues contains cancer-specific mutations.

Liquid biopsies are promising tools for early diagnosis and residual disease monitoring in patients with cancer, and circulating tumor DNA isolated from plasma has been extensively studied as it has been shown to contain tumor-specific mutations. Extracellular vesicles (EVs) present in tumor tissues carry tumor-derived molecules such as proteins and nucleic acids, and thus EVs can potentially represent a source of cancer-specific DNA. Here we identified the presence of tumor-specific DNA mutations in EVs isolated from six human melanoma metastatic tissues and compared the results with tumor tissue DNA and plasma DNA. Tumor tissue EVs were isolated using enzymatic treatment followed by ultracentrifugation and iodixanol density cushion isolation. A panel of 34 melanoma-related genes was investigated using ultra-sensitive sequencing (SiMSen-seq). We detected mutations in six genes in the EVs (BRAF, NRAS, CDKN2A, STK19, PPP6C, and RAC), and at least one mutation was detected in all melanoma EV samples. Interestingly, the mutant allele frequency was higher in DNA isolated from tumor-derived EVs compared to total DNA extracted directly from plasma DNA, supporting the potential role of tumor EVs as future biomarkers in melanoma.

Clinical Significance and Molecular Characteristics of Circulating Plasma Cells in Multiple Myeloma

BACKGROUND: Multiple myeloma (MM) is caused and characterized by clonal proliferation of malignant plasma cells. Clonal plasma cells are predominantly distributed in the bone marrow (BM), yet, along with the technical improvement, clonal plasma cells (CPC) can be detected in the peripheral blood of most patients with MM. Previous studies, along with ours, have revealed an association between CPC and prognosis. However, the relevance of CPC to the clinical features and prognosis in Chinses population, and the mechanisms underlying the formation of CPC has not been fully elucidated. METHODS: Patients with newly diagnosed MM were included in this study. We used multi-parameter flow cytometry (MFC) for CPC quantification and next-generation sequencing (NGS) technology for mutational landscape mapping to identify the correlation of CPC level with clinical characteristics and the mutations. RESULTS: A total of 301 patients with newly diagnosed MM were included in this investigation. It is demonstrated that CPC quantification could effectively mirror the tumor load, and CPC≥0.105% at diagnosis or detectable CPC after therapy indicates poor treatment response and adverse outcome. The introduction of CPC level into the R-ISS system enables a more robust discrimination of prognosis, especially for the larger number of R-ISS Ⅱ patients. Interestingly, we noticed an elevated proportion of light-chain MM in patients with higher CPC. Mutational landscape revealed that TP53 mutations and pathways involving chromatin or chromosome regulation and adhesion tended to have significantly higher CPC levels, suggesting a potential mechanism accounting for CPC formation. CONCLUSION: Accordingly, the detection of CPC by MFC may provide a less-invasive and reliable approach for risk stratification and disease monitoring in patients with MM. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Reliable Flow-Cytometric Approach for Minimal Residual Disease Monitoring in Patients with B-Cell Precursor Acute Lymphoblastic Leukemia after CD19-Targeted Therapy.

We aimed to develop an antibody panel and data analysis algorithm for multicolor flow cytometry (MFC), which is a reliable method for minimal residual disease (MRD) detection in patients with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) treated with CD19-directed therapy. The development of the approach, which was adapted for the case of possible CD19 loss, was based on the additional B-lineage marker expression data obtained from a study of primary BCP-ALL patients, an analysis of the immunophenotypic changes that occur during blinatumomab or CAR-T therapy, and an analysis of very early CD19-negative normal BCPs. We have developed a single-tube 11-color panel for MFC-MRD detection. CD22- and iCD79a-based primary B-lineage gating (preferably consecutive) was recommended. Based on patterns of antigen expression changes and the relative expansion of normal CD19-negative BCPs, guidelines for MFC data analysis and interpretation were established. The suggested approach was tested in comparison with the molecular techniques: IG/TR gene rearrangement detection by next-generation sequencing (NGS) and RQ-PCR for fusion-gene transcripts (FGTs). Qualitative concordance rates of 82.8% and 89.8% were obtained for NGS-MRD and FGT-MRD results, respectively. We have developed a sensitive and reliable approach that allows MFC-MRD monitoring after CD19-directed treatment, even in the case of possible CD19 loss.

A new aberrantly spliced BCR-ABL1 transcript variant (e13a1) identified in routine monitoring using different quantitative reverse transcription polymerase chain reaction techniques in a patient with chronic myeloid leukemia.

Quantitative reverse transcription polymerase chain reaction (qRT-PCR) of BCR-ABL1 transcript level is an essential part of routine disease monitoring in patients with chronic myeloid leukemia. One patient sample (e13a2 transcript detected by nested PCR) attracted attention by revealing an aberrantly spliced BCR-ABL1 transcript variant e13a1. The last 38 base pairs (bp) of BCR exon 13 were replaced by a 37 bp insertion of the ABL1 intron 1-2/exon 1 sequence. The rare aberrant BCR-ABL1 fusion transcript can cause discrepancies in molecular diagnostics. This scenario highlights the importance of an individual characterization of the BCR-ABL1 fusion sequence in case of unclear qRT-PCR results.

Molecular disease monitoring in patients with relapsed/refractory B-cell non-Hodgkin lymphoma receiving anti-CD19 CAR T-cell therapy.

7531 Background: Chimeric antigen receptor (CAR) T-cell therapy has improved the historically poor outcomes for relapsed and refractory (R/R) B-cell non-Hodgkin’s lymphoma (NHL). However, nearly 60% of patients will either fail to respond or relapse after CAR T-cell therapy. Currently, PET/CT scans are used to assess response. Cell-free circulating tumor DNA (ctDNA) is released by tumor cells into the peripheral blood and can be measured for minimal residual disease (MRD) assessment. Methods: In this retrospective, IRB approved pilot study, archived lymphoma tissues and ctDNA from peripheral blood samples on day 0, 14, 28, 56, 80, 180, and 365 after CAR T-cell infusion from 10 patients with R/R NHL were collected for next-generation sequencing (NGS) of clonal variable-diversity-joining (VDJ) rearrangements [Adaptive biotechnologies (Seattle, WA)]. Response was assessed by PET/CT on days 30, 60, 90, 180 and 365 and graded according to the Lugano 2014 criteria. The primary endpoint was to determine the feasibility of detecting ctDNA to monitor disease response after anti-CD19 CAR T-cells. The secondary endpoint was to compare the sensitivity/specificity of MRD assessment from ctDNA to PET/CT imaging. Results: Nine out of 10 patients with a trackable sequence [median age 69 (range: 56-76); 55.6% male; median LDH 224], were included in this study. Each received tisagenlecleucel CAR T-cell therapy after median two prior treatments (range: 2-4). 7/9 patients had R/R diffuse large B-cell lymphoma (DLBCL), and 2/9 had transformed follicular lymphoma. At a median follow up of 12.7 months (range: 1.5-30 months), four patients were alive. By day 90, three patients (33.3%) achieved a radiographic complete response (CR) whilst six patients (66.6%) had progressive disease (PD). MRD and radiographic response are outlined in the Table. Detectable MRD on day 14 or day 28 had 83% sensitivity and 100% specificity for radiographic progression at any time before one year. For patients with PD, the median (interquartile range) MRD at day 0, 14, and 28 were 17.31 (1.01, 96.84), 9.12 (0.30, 18.8), and 23.77 (8.01, 137.53) copies per milliliter (mL), respectively. For patients with detectable MRD at day 28, mOS and mPFS were 205 and 38 days, respectively. Conclusions: Our pilot study demonstrated that monitoring MRD was a sensitive and specific method to detect disease response and relapse. In addition, MRD can be monitored more frequently, thus allowing for earlier detection of relapse. MRD and PET/CT identified progressive disease (PD) or complete response (CR) by day 90 in nine patients (A-I) with R/R NHL post CAR T-cell infusion.[Table: see text]

Clinical Applications of FDG-PET Scan in Arrhythmic Myocarditis

Background18F-fluorodeoxyglucose positron emission tomography (FDG-PET) scan has no recognized role in diagnosis, prognosis, and disease monitoring in patients with arrhythmic myocarditis. ObjectivesThe purpose of this study was to investigate the value of FDG-PET scan in arrhythmic myocarditis. MethodsThe authors enrolled 75 consecutive patients (age 47 ± 14 years, 65% men) undergoing FDG-PET scan for arrhythmic myocarditis. Myocarditis was diagnosed by endomyocardial biopsy (EMB) and, whenever applicable, cardiac magnetic resonance (CMR). ResultsIndications for FDG-PET scan included either contraindication to CMR (n = 50) or mismatch between CMR and EMB (n = 25). Overall, 50 patients (67%) had positive FDG-PET. Sensitivity was 75% referring to EMB, and 73% to CMR. Specificity was 67% referring to EMB, and 59% to CMR. FDG-PET accuracy was lower in the presence of borderline myocarditis, and either late (>30 days) or on-immunosuppression FDG-PET scanning. Anteroseptal distribution pattern, found in 12 of 50 (24%) patients including 7 of 7 cardiac sarcoidosis cases, was associated with greater occurrence of ventricular arrhythmias and atrioventricular blocks in 4.2 ± 1.7 years of follow-up (10 of 12 vs 7 of 38, and 7 of 12 vs 0 of 38, respectively; both P < 0.001). In 39 patients (52%), FDG-PET was repeated by 13 ± 2 months, allowing immunosuppression withdrawal after FDG uptake normalization either by first (76%) or second reassessment (24%). ConclusionsFDG-PET scan may be a clinically useful diagnostic technique in arrhythmic myocarditis, in particular when CMR is unsuitable because of irregular heartbeat or implantable cardioverter-defibrillator–related artifacts. Anteroseptal FDG distribution is associated with a worse arrhythmic outcome and should raise the suspicion of cardiac sarcoidosis. During follow-up, repeated FDG-PET allows myocarditis monitoring to guide immunosuppression withdrawal.

Clinical significance of baseline Pan-Immune-Inflammation Value and its dynamics in metastatic colorectal cancer patients under first-line chemotherapy

Pan-Immune-Inflammation Value (PIV) has been recently proposed as a new blood-based prognostic biomarker in metastatic colorectal cancer (mCRC). Herein we aimed to validate its prognostic significance and to evaluate its utility for disease monitoring in patients with mCRC receiving first-line chemotherapy. We conducted a single-centre retrospective study involving 130 previously untreated mCRC patients under first-line standard chemotherapy in a real-world scenario. PIV was calculated as (neutrophil count × platelet count × monocyte count)/lymphocyte count at three different time-points: baseline, week 4 after therapy initiation, and at disease progression. We analyzed the influence of baseline PIV on overall survival (OS), progression-free survival (PFS), disease control rate (DCR), and overall response rate (ORR). We also explored the utility of PIV dynamics for disease monitoring. Baseline PIV high was significantly associated with worse OS in univariate [hazard ratio (HR) = 2.10, 95% CI, 1.41–3.15; p = 0.000299] and multivariate (HR = 1.82, 95% CI, 1.15–2.90; p = 0.011) analyses. Baseline PIV was also associated with worse PFS in univariate (HR = 2.04, 95% CI, 1.40–2.97; p = 0.000187) and multivariate (HR = 1.56, 95% CI, 1.05–2.31; p = 0.026) analyses. Baseline PIV was not correlated either with DCR or ORR. Regarding PIV dynamics, there was a statistically significant increase from week 4 to disease progression (p = 0.0003), which was at the expense of cases with disease control as best response (p < 0.0001). In conclusion, this study validates the prognostic significance of baseline PIV in patients with mCRC receiving first-line standard chemotherapy in a real-world scenario. Moreover, it suggests the potential utility of PIV monitoring to anticipate the disease progression among those patients who achieve initial disease control.

A Wearable Respiration Sensor for Real-Time Monitoring of Chronic Kidney Disease.

Human respiration is accompanied with abundant physiological and pathological information, such as the change in ammonia (NH3) content, which is related to chronic kidney disease (CKD); hence, monitoring the breathing behavior helps in health assessment and illness prediction. In this work, a wearable respiration sensor based on CeO2@polyaniline (CeO2@PANI) nanocomposites that underwent a hydrogen plasma treatment is developed. The results unambiguously show that the response of the corresponding nanocomposites is significantly enhanced from 165 to 670% to 100 ppm NH3 compared to the counterpart that did not undergo hydrogen plasma treatment and even reaches 24% to 50 ppb NH3, suggesting its fascinating capability of detecting the trace level of NH3 in human breathing. The superior response for NH3 is ascribed to the stable oxygen vacancies produced by the hydrogen plasma treatment. Furthermore, the clinical tests for patients with uremia suggest that the as-designed sensor has potential applications in clinical monitoring for CKD. Herein, this work offers a new strategy to obtain respiration sensors with high performance and provides a feasible approach for health evaluation and disease monitoring of patients with CKD.

Value of measurable residual disease monitoring in patients with acute promyelocytic leukemia in the era of frontline ‘chemotherapy-free’ therapy

Acute promyelocytic leukemia (APL) is characterized by the chromosomal translocation t(15;17) and the resulting gene PML-RARA, used for measurable residual disease (MRD) monitoring. Despite highly effective therapy for APL, MRD monitoring practices are not fully established. We aimed to assess the value of MRD monitoring by RT-qPCR in patients with APL treated with ATRA and arsenic trioxide +/– GO. We reviewed 223 patients with APL treated with this regimen. RT-qPCR for PML-RARA was measured every 3 months, and at 12, 18, and 24 months after therapy. Seven patients relapsed. Time to relapse was 7.9–12.4 months in 6 patients, and one patient relapsed after 79.5 months. These data show that MRD monitoring may be important for the detection of relapse in patients treated with this regimen within one year after completing therapy, however, since late molecular relapse is rare, our data suggest a low value of MRD monitoring beyond that first year.