Flow Cytometric Assessment of Malignant Hematologic Disorders.

Multiparameter flow cytometry (MPF) is an essential component of the diagnostic workup of hematologic malignancies. Recently developed tools have expanded the utility of MPF in detecting T-cell clonality and myelomonocytic dysplasia. Minimal/measurable residual disease analysis has long been established as critical in the management of B-lymphoblastic leukemia and is emerging as a useful tool in myeloid malignancies. With the continued increased complexity of MPF assays, emerging tools for data collection and analysis will allow users to take full advantage of MPF in the diagnosis of hematologic disease.

Decoding the Dynamics of Circulating Tumor DNA in Liquid Biopsies.

Circulating tumor DNA (ctDNA), a fragment of tumor DNA found in the bloodstream, has emerged as a revolutionary tool in cancer management. This review delves into the biology of ctDNA, examining release mechanisms, including necrosis, apoptosis, and active secretion, all of which offer information about the state and nature of the tumor. Comprehensive DNA profiling has been enabled by methods such as whole genome sequencing and methylation analysis. The low abundance of the ctDNA fraction makes alternative techniques, such as digital PCR and targeted next-generation exome sequencing, more valuable and accurate for mutation profiling and detection. There are numerous clinical applications for ctDNA analysis, including non-invasive liquid biopsies for minimal residual disease monitoring to detect cancer recurrence, personalized medicine by mutation profiling for targeted therapy identification, early cancer detection, and real-time evaluation of therapeutic response. Integrating ctDNA analysis into routine clinical practice creates promising avenues for successful and personalized cancer care, from diagnosis to treatment and follow-up.

[Clinical efficacy and safety of blinatumomab bridging CAR-T cell therapy in the treatment of patients with adult acute B-cell lymphoblastic leukemia].

Objective: Exploring the efficacy and safety of bridging blinatumomab (BiTE) in combination with chimeric antigen receptor T (CAR-T) cell therapy for the treatment of adult patients with acute B-cell lymphoblastic leukemia (B-ALL) . Methods: Clinical data from 36 adult B-ALL patients treated at the First Affiliated Hospital of Suzhou University from August 2018 to May 2023 were retrospectively analyzed. A total of 36 cases were included: 18 men and 18 women. The median age was 43.5 years (21-72 years). Moreover, 21 cases of Philadelphia chromosome-positive acute lymphoblastic leukemia were reported, and 16 of these cases were relapsed or refractory. Eighteen patients underwent blinatumomab bridging followed by CAR-T cell therapy, and 18 patients received CAR-T cell therapy. This study analyzed the efficacy and safety of treatment in two groups of patients. Results: In the BiTE bridge-to-CAR-T group, 16 patients achieved complete remission (CR) after BiTE immunotherapy, with a CR rate of 88.9%. One month after bridging CAR-T therapy, bone marrow examination showed a CR rate of 100.0%, and the minimal residual disease (MRD) negativity rate was higher than the nonbridging therapy group (94.4% vs. 61.1%, Fisher, P=0.041). The incidence of cytokine release syndrome and other adverse reactions in the BiTE bridge-to-CAR-T group was lower than that in the nonbridging therapy group (11.1% vs. 50.0%, Fisher, P=0.027). The follow-up reveals that 13 patients continued to maintain MRD negativity, and five patients experienced relapse 8.40 months (2.57-10.20 months) after treatment. Two of five patients with relapse achieved CR after receiving the second CAR-T cell therapy. In the nonbridging therapy group, 10 patients maintained continuous MRD negativity, 7 experienced relapse, and 6 died. The 1 year overall survival rate in the BiTE bridge-to-CAR-T group was higher than that in the nonbridging therapy group, with a statistically significant difference at the 0.1 level (88.9%±10.5% vs. 66.7%±10.9%, P=0.091) . Conclusion: BiTE bridging CAR-T cell therapy demonstrates excellent efficacy in adult B-ALL treatment, with a low recent recurrence rate and ongoing assessment of long-term efficacy during follow-up.

Minimal residual disease monitoring via ctDNA: a case report of Lynch syndrome with synchronous colorectal cancer and review of literature.

Background: The investigation of circulating tumor DNA (ctDNA) as a substitute for minimal residual disease (MRD) has been a central focus in various clinical trials, with findings highlighting its effectiveness as a sensitive marker for detecting recurrence. In 2018, a joint review by the American Society of Clinical Oncology and the College of American Pathologists acknowledged a lack of current evidence guiding clinical decisions regarding ctDNA. Nevertheless, there are a multitude of ongoing studies exploring the future applications of ctDNA and its role in clinical decision making for select patient populations. Case Description: The case presented involves a patient with Lynch syndrome who developed synchronous left-sided colorectal cancers (CRC). Each primary malignancy exhibited a distinct mutational profile, introducing complexity to the personalized tumor-informed assays used for quantifying ctDNA levels. Initial ctDNA levels were negative until the assay was calibrated to the transverse colon primary tumor. Unfortunately, surveillance imaging showed radiographic recurrence coinciding with positive ctDNA findings. Treatment with the anti-PD-1 inhibitor pembrolizumab was initiated, resulting in the clearance of ctDNA after just four cycles. As of now, there is no radiographic or biologic evidence indicating disease recurrence. Conclusions: This case study sheds light on the evolving landscape and current limitations of ctDNA as a surrogate for MRD. We describe a patient with synchronous CRC who had radiographic recurrence and a negative MRD assay. Current tumor-informed assays are limited in their capacity to detect a single tumor, and by nature can miss both synchronous and metachronous malignancies. Assays tailored to multiple tumors or utilizing tumor agnostic methods should be a part of clinical decision making in this patient population.

Circulating tumor DNA to guide diagnosis and treatment of localized and locally advanced non-small cell lung cancer.

Liquid biopsy is a minimally invasive method for biomarkers detection in body fluids, particularly in blood, which offers an elevated and growing number of clinical applications in oncology. As a result of the improvement in the techniques for DNA analysis, above all next-generation sequencing (NGS) assays, circulating tumor DNA (ctDNA) has become the most informing tumor-derived material for most types of cancer, including non-small cell lung cancer (NSCLC). Although ctDNA concentration is higher in patients with advanced tumors, it can be detected even in patients with early-stage disease. Therefore, numerous clinical applications of ctDNA in the management of early-stage lung cancer are emerging, such as lung cancer screening, the identification of minimal residual disease (MRD), and the prediction of relapse before radiologic progression. Moreover, a high number of clinical trials are ongoing to better define the impact of ctDNA evaluation in this setting. Aim of this review is to offer a comprehensive overview of the most relevant implementations in using ctDNA for the management of early-stage lung cancer, addressing available data, technical aspects, limitations, and future perspectives.

Tumor-informed deep sequencing of ctDNA detects minimal residual disease and predicts relapse in osteosarcoma.

Background: Current surveillance modalities of osteosarcoma relapse exhibit limited sensitivity and specificity. Although circulating tumor DNA (ctDNA) has been established as a biomarker of minimal residual disease (MRD) in many solid tumors, a sensitive ctDNA detection technique has not been thoroughly explored for longitudinal MRD detection in osteosarcoma. Methods: From August 2019 to June 2023, 59 patients diagnosed with osteosarcoma at the First Affiliated Hospital of Sun Yat-sen University were evaluated in this study. Tumor-informed MRD panels were developed through whole exome sequencing (WES) of tumor tissues. Longitudinal blood samples were collected during treatment and subjected to multiplex PCR-based next-generation sequencing (NGS). Kaplan-Meier curves and Log-rank tests were used to compare outcomes, and Cox regression analysis was performed to identify prognostic factors. Findings: WES analysis of 83 patients revealed substantial mutational heterogeneity, with non-recurrent mutated genes accounting for 58.1%. Tumor-informed MRD panels were successfully obtained for 85.5% of patients (71/83). Among 59 patients with successful MRD panel customization and available blood samples, 13 patients exhibited positive ctDNA detection after surgery. Patients with negative post-operative ctDNA had better event-free survival (EFS) compared to those with positive ctDNA, at 1-6 months after surgery, after adjuvant chemotherapy, and more than 6 months after surgery (p < 0.05). In both univariate and multivariate Cox regression analysis, ctDNA results emerged as a significant predictor of EFS (p < 0.05). ctDNA detection preceded positive imaging in 5 patients, with an average lead time of 92.6 days. Thirty-nine patients remained disease-free, with ctDNA results consistently negative or turning negative during follow-up. Interpretation: Our study underscores the applicability of tumor-informed deep sequencing of ctDNA in osteosarcoma MRD surveillance and, to our knowledge, represents the largest cohort to date. ctDNA detection is a significant prognostic factor, enabling the early identification of tumor relapse and progression compared to standard imaging, thus offering valuable insights in guiding osteosarcoma patient management. Funding: The Grants of National Natural Science Foundation of China (No. 82072964, 82072965, 82203798, 82203026), the Natural Science Foundation of Guangdong (No. 2023A1515012659, 2023A1515010302), and the Regional Combination Project of Basic and Applied Basic Research Foundation of Guangdong (No. 2020A1515110010).

Molecular Disease Monitoring in Patients With Relapsed/refractory B-Cell Lymphoma Receiving Anti-CD19 CAR T-Cell Therapy.

BACKGROUND: Chimeric antigen receptor (CAR) T-cell therapy has improved the historically poor outcomes for relapsed and refractory (R/R) large B-cell non-Hodgkin's lymphoma (LBCL). 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 tissue and ctDNA from peripheral blood samples on day 0, 14, 28, 56, 90, 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 90 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-cell therapy. 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 (tisa-cel) CAR T-cell therapy after median 2 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), 4 patients were alive. By day 90, 3 patients (33.3%) achieved a radiographic complete response (CR) whilst 6 patients (66.6%) had progressive disease (PD). Detectable MRD on day 14 or day 28 had 83% sensitivity and 100% specificity for radiographic progression at any time before 1 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 6.7 and 1.3 months, respectively. CONCLUSION: Monitoring MRD was a sensitive and specific method to detect poor response to tisa-cel. Additional studies evaluating MRD more frequently and with different products are warranted.

Analysis of Circulating Tumor DNA Predicts Outcomes of Short-Course Consolidation Immunotherapy in Unresectable Stage III NSCLC.

INTRODUCTION: The current standard of care for patients with inoperable stage III non-small cell lung cancer includes chemoradiotherapy (CRT) followed by 1 year of checkpoint inhibitor (CPI) therapy. Nevertheless, the optimal duration of consolidation CPI remains unknown. Here, we characterized the relationship between circulating tumor DNA (ctDNA) minimal residual disease (MRD) and clinical outcomes of patients with unresectable locally advanced non-small cell lung cancer treated on a phase 2 trial of short-course consolidation immunotherapy after CRT, with the goal of testing whether ctDNA may be able to identify patients who do not require a full year of treatment. METHODS: Plasma samples for ctDNA analysis were collected from patients on the Big Ten Cancer Research Consortium LUN 16-081 trial after completion of CRT, before day 1 of cycle 2 (C2D1) of CPI (i.e., 1 mo after treatment start), and at the end of up to 6 months of treatment. Tumor-informed ctDNA MRD analysis was performed using cancer personalized profiling by deep sequencing. Levels of ctDNA at each time point were correlated with clinical outcomes. RESULTS: Detection of ctDNA predicted significantly inferior progression-free survival after completion of CRT (24-mo 29% versus 65%, p = 0.0048), before C2D1 of CPI (24-mo 0% versus 72%, p < 0.0001) and at the end of CPI (24-mo 15% versus 67%, p = 0.0011). In addition, patients with decreasing or undetectable ctDNA levels after 1 cycle of CPI had improved outcomes compared with patients with increasing ctDNA levels (24-mo progression-free survival 72% versus 0%, p < 0.0001). Progression of disease occurred within less than 12 months of starting CPI in all patients with increasing ctDNA levels at C2D1. CONCLUSIONS: Detection of ctDNA before, during, or after 6 months of consolidation CPI is strongly associated with inferior outcomes. Our findings suggest that analysis of ctDNA MRD may enable personalizing the duration of consolidation immunotherapy treatment.

Clinical application of ctDNA in early diagnosis, treatment and prognosis of patients with non-small cell lung cancer.

Lung cancer is one of the most common malignancies worldwide, with non-small cell lung cancer (NSCLC) being the most common type. As understanding of precise treatment options for NSCLC deepens, circulating tumor DNA (ctDNA) has emerged as a potential biomarker that has become a research hotspot and may represent a new approach for the individualized diagnosis and treatment of NSCLC. This article reviews the applications of ctDNA for the early screening of patients with NSCLC, guiding targeted therapy and immunotherapy, evaluating chemotherapy and postoperative efficacy, assessing prognosis and monitoring recurrence. With the in-depth study of the pathogenesis of NSCLC, plasma ctDNA may become an indispensable part of the precise treatment of NSCLC, which has great clinical application prospects.

[Box: see text].

Evaluation of a New Closed-System Automated RT-qPCR Assay for the Rapid Detection and Monitoring of Common Nucleophosmin Mutations in Patients with Acute Myeloid Leukemia.

Quantitative assessment of nucleophosmin 1 (NPM1) mutation status is integral to evaluating measurable residual disease (MRD) in NPM1-mutated acute myeloid leukemia (AML) patients. In a retrospective study, leftover peripheral blood (PB) specimens (n = 40) which were collected for routine clinical diagnostic evaluations of AML disease burden were tested by both a novel automated RT-qPCR quantitative NPM1 assay (Xpert NPM1 mutation assay) and the NPM1 mutA, mutB&D MutaQuant kit. Based on a Deming regression analysis, there was a high correlation (slope = 0.92; intercept = 0.12; Pearson's r = 0.982) between the quantitative results of the Xpert NPM1 mutation assay and the NPM1 mutA, mutB&D MutaQuant kit. The Xpert test quantitative results are thus highly correlated with the comparator method and the former has potential as a useful alternative for the monitoring of AML patients with a known NPM1 mutation.

Donor lymphocyte infusions: An experience from a tertiary care center of North India.

Donor lymphocyte infusions (DLIs) are often recommended products after allogeneic hematopoietic stem cell transplant to increase graft - versus - leukemia effect. More success rate of DLI has been reported in relapsed posttransplant chronic myeloid leukemia. Whatever the indication for DLI, mortality related to post-DLI infusion is 5%-20%, and more than one-third of patients will develop acute and/or chronic graft versus host disease (GVHD) after DLI. We report two cases where DLIs were used for residual disease after posttransplant. Both of DLI went uneventful. None of the patient's developed signs of GVHD postinfusion. Although both patients expired with different causes, none were related to DLI infusion. Information from published literature suggests that DLI should be administered early after relapse or as a prophylactic strategy in patients receiving T-cell-depleted grafts, and patients with aggressive diseases may benefit from disease reduction before DLI. However, further evidence is required to evaluate its efficacy, especially in relapsed or residual hematological malignancies.

Mutation and cell state compatibility is required and targetable in Ph+ acute lymphoblastic leukemia minimal residual disease.

Efforts to cure BCR::ABL1 B cell acute lymphoblastic leukemia (Ph+ ALL) solely through inhibition of ABL1 kinase activity have thus far been insufficient despite the availability of tyrosine kinase inhibitors (TKIs) with broad activity against resistance mutants. The mechanisms that drive persistence within minimal residual disease (MRD) remain poorly understood and therefore untargeted. Utilizing 13 patient-derived xenograft (PDX) models and clinical trial specimens of Ph+ ALL, we examined how genetic and transcriptional features co-evolve to drive progression during prolonged TKI response. Our work reveals a landscape of cooperative mutational and transcriptional escape mechanisms that differ from those causing resistance to first generation TKIs. By analyzing MRD during remission, we show that the same resistance mutation can either increase or decrease cellular fitness depending on transcriptional state. We further demonstrate that directly targeting transcriptional state-associated vulnerabilities at MRD can overcome BCR::ABL1 independence, suggesting a new paradigm for rationally eradicating MRD prior to relapse. Finally, we illustrate how cell mass measurements of leukemia cells can be used to rapidly monitor dominant transcriptional features of Ph+ ALL to help rationally guide therapeutic selection from low-input samples.

Comparing the HER2 Status of the Primary Tumor to That of Disseminated Tumor Cells in Early Breast Cancer.

Breast cancer remains a leading cause of cancer mortality in women globally. Despite advancements in systemic therapy, the risk of distant recurrence persists even after such treatment and may be linked to disseminated tumor cells (DTCs). Variability in molecular characteristics between primary tumors (PTs) and distant metastases underscores the need to comprehensively understand metastatic pathways. This retrospective study investigated discrepancies between HER2 expression in PTs and DTCs and their implications for survival outcomes in 201 early breast cancer (EBC) patients. We found a significant association between HER2 expression in PTs and DTCs when classifying tumors as HER2-high/low/negative. Patients whose HER2 status was discordant between PTs and DTCs exhibited worse distant disease-free survival than those with concordant status. Multivariate analysis confirmed the HER2 status of DTCs as an independent prognostic factor for distant DFS. These findings emphasize the importance of assessing HER2 expression in DTCs and its potential implications for tailored therapy strategies in EBC. Furthermore, prospective trials are needed to validate these findings and explore targeted therapies based on the molecular characteristics of DTCs.

The role of minimal residual disease and serum free light chain ratio in the management of multiple myeloma.

Multiple myeloma (MM) denotes a cancerous growth characterized by abnormal proliferation of plasma cells. Growing evidence suggests that the complexity in addressing MM lies in the presence of minimal residual disease (MRD) within the body. MRD assessment is becoming increasingly important for risk assessment in patients with MM. Similarly, the levels of serum free protein light chain and their ratio play a crucial role in assessing the disease burden and changes in MM. In this paper, we review and explore the utilization of MRD and serum free light chain ratio in the treatment of MM, delving into their respective characteristics, advantages, disadvantages, and their interrelation.

SWIGH-SCORE: A translational light-weight approach in computational detection of rearranged immunoglobulin heavy chain to be used in monoclonal lymphoproliferative disorders.

We present a lightweight tool for clonotyping and measurable residual disease (MRD) assessment in monoclonal lymphoproliferative disorders. It is a translational method that enables computational detection of rearranged immunoglobulin heavy chain gene sequences.•The swigh-score clonotyping tool emphasizes parallelization and applicability across sequencing platforms.•The algorithm is based on an adaptation of the Smith-Waterman algorithm for local alignment of reads generated by 2nd and 3rd generation of sequencers.For method validation, we demonstrate the targeted sequences of immunoglobulin heavy chain genes from diagnostic bone marrow using serial dilutions of CD138+ plasma cells from a patient with multiple myeloma. Sequencing libraries from diagnostic samples were prepared for the three sequencing platforms, Ion S5 (Thermo Fisher Scientific), MiSeq (Illumina), and MinION (Oxford Nanopore), using the LymphoTrack assay. Basic quality filtering was performed, and a Smith-Waterman-based swigh-score algorithm was developed in shell and C for clonotyping and MRD assessment using FASTQ data files. Performance is demonstrated across the three different sequencing platforms.

Variant-specific BCR::ABL1 quantification discrepancy in chronic myeloid leukemia.

INTRODUCTION: Accurate quantification of the BCR::ABL1 fusion gene in whole blood is pivotal for the clinical management of chronic myeloid leukemia (CML) patients. The fusion protein encoded by BCR::ABL1 can vary in size, depending on the BCR and/or ABL1 gene breakpoint. The vast majority of CML patients have a p210 BCR::ABL1 fusion gene (M-BCR), which can be attributed to the presence of either e14a2 (b3a2) or e13a2 (b2a2) mRNA transcript junctions. METHODS: Twenty-five CML samples were analyzed in two different ISO15189-accredited centers that both use an Europe Against Cancer-based quantitative polymerase chain reaction (qPCR) protocol. Reanalysis of the sample set with transcript-specific standard curves and digital droplet PCR (ddPCR) were performed. RESULTS: qPCR quantification revealed a significant (up to 1 log) difference specifically for the e13a2 transcript variant in contrast to e14a2 transcripts (Hodges-Lehman 4.29; p < 0.001). Reanalysis of the sample set with transcript-specific standard curves abolishes the initial transcript-specific difference (Hodges-Lehman 0.003; p = 0.8192). Comparison of transcript-specific qPCR results of both centers with ddPCR, an absolute quantification method, showed a statically significant association, especially in the lower range, indicating the clinical utility of transcript-specific or absolute quantification methods. CONCLUSION: Our data show that differences between transcript-specific quantification might exist between centers, leading to potential clinical impact on the follow-up of CML patients. The use of transcript-specific standard curves for qPCR quantification, or absolute quantification, can significantly reduce these differences. Specific attention should be applied to the interpretation of quantification differences of CML patients that switch between diagnostic centers.

Improvement of daratumumab- or elotuzumab-mediated NK cell activity by the bi-specific 4-1BB agonist, DARPin α-FAPx4-1BB: A preclinical study in multiple myeloma.

Multiple myeloma (MM) progression is closely dependent on cells in the bone marrow (BM) microenvironment, including fibroblasts (FBs) and immune cells. In their BM niche, MM cells adhere to FBs sustaining immune evasion, drug resistance and the undetectable endurance of tumor cells known as minimal residual disease (MRD). Here, we describe the novel bi-specific designed ankyrin repeat protein (DARPin) α-FAPx4-1BB (MP0310) with FAP-dependent 4-1BB agonistic activity. The α-FAPx4-1BB DARPin simultaneously binds to FAP and 4-1BB overexpressed by activated FBs and immune cells, respectively. Although flow cytometry analysis showed that T and NK cells from MM patients were not activated and did not express 4-1BB, stimulation with daratumumab or elotuzumab, monoclonal antibodies (mAbs) currently used for the treatment of MM, significantly upregulated 4-1BB both in vitro and in MM patients following mAb-based therapy. The mAb-induced 4-1BB overexpression allowed the engagement of α-FAPx4-1BB that acted as a bridge between FAP+FBs and 4-1BB+NK cells. Therefore, α-FAPx4-1BB enhanced both the adhesion of daratumumab-treated NK cells on FBs as well as their activation by improving release of CD107a and perforin, hence MM cell killing via antibody-mediated cell cytotoxicity (ADCC). Interestingly, α-FAPx4-1BB significantly potentiated daratumumab-mediated ADCC in the presence of FBs, suggesting that it may overcome the BM FBs' immunosuppressive effect. Overall, we speculate that treatment with α-FAPx4-1BB may represent a valuable strategy to improve mAb-induced NK cell activity fostering MRD negativity in MM patients through the eradication of latent MRD cells.

Liquid biopsy for molecular characterization of diffuse large B-cell lymphoma and early assessment of minimal residual disease.

Circulating tumour DNA (ctDNA) allows genotyping and minimal residual disease (MRD) detection in lymphomas. Using a next-generation sequencing (NGS) approach (EuroClonality-NDC), we evaluated the clinical and prognostic value of ctDNA in a series of R-CHOP-treated diffuse large B-cell lymphoma (DLBCL) patients at baseline (n = 68) and after two cycles (n = 59), monitored by metabolic imaging (positron emission tomography combined with computed tomography [PET/CT]). A molecular marker was identified in 61/68 (90%) ctDNA samples at diagnosis. Pretreatment high ctDNA levels significantly correlated with elevated lactate dehydrogenase, advanced stage, high-risk International Prognostic Index and a trend to shorter 2-year progression-free survival (PFS). Valuable NGS data after two cycles of treatment were obtained in 44 cases, and 38 achieved major molecular response (MMR; 2.5-log drop in ctDNA). PFS curves displayed statistically significant differences among those achieving MMR versus those not achieving MMR (2-year PFS of 76% vs. 0%, p < 0.001). Similarly, more than 66% reduction in ΔSUVmax by PET/CT identified two subgroups with different prognosis (2-year PFS of 83% vs. 38%; p < 0.001). Combining both approaches MMR and ΔSUVmax reduction, a better stratification was observed (2-year PFS of 84% vs. 17% vs. 0%, p < 0.001). EuroClonality-NDC panel allows the detection of a molecular marker in the ctDNA in 90% of DLBCL. ctDNA reduction at two cycles and its combination with interim PET results improve patient prognosis stratification.

[The value of minimal residual disease and IKZF1 deletion for predicting prognosis in adult patients with B-cell acute lymphoblastic leukemia].

Objective: To reassess the prognostic value of minimal residual disease (MRD) and IKZF1 gene deletions in adults with B-cell acute lymphoblastic leukemia (B-ALL) who received pediatric-specific chemotherapy regimens during the Nanfang Hospital PDT-ALL-2016 trial. Methods: We retrospectively analyzed the prognosis of 149 adult patients with B-ALL who were admitted to Nanfang Hospital from January 2016 to September 2020. Prognostic factors were identified using Cox regression models. Results: The complete remission rate was 93.2% in 149 patients, with a 5-year overall survival (OS) rate of (54.3±5.0) % and a cumulative incidence of relapse (CIR) of (47.5±5.2) %. The Cox regression analysis revealed that MRD positivity at day 45 (MRD(3)) after induction therapy was independently associated with relapse risk (HR=2.535, 95%CI 1.122-5.728, P=0.025). Deletion of IKZF1 gene was independently associated with mortality risk (HR=1.869, 95%CI 1.034-3.379, P=0.039). Based on MRD(3) and IKZF1 gene status, we categorized adult patients with B-ALL into the low-risk (MRD(3)-negative and IKZF1 gene deletion-negative) and high-risk (MRD(3)-positive and/or IKZF1 gene wild type) groups. The 5-year OS and CIR rates were (45.5±6.0) % vs (69.4±8.6) % (P<0.001) and (61.6±8.3) % vs (25.5±6.5) % (P<0.001), respectively, in the high-risk and low-risk groups, respectively. The multivariate analysis showed that the high-risk group was an independent risk factor for OS (HR=3.937, 95%CI 1.975-7.850, P<0.001) and CIR (HR=4.037, 95%CI 2.095-7.778, P<0.001) . Conclusion: The combined use of MRD and IKZF1 gene in prognostic stratification can improve clinical outcome prediction in adult patients with B-ALL, helping to guide their treatment.