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Circulating Tumor DNA Profiling Defines Risk Classification in Patients With Ewing Sarcoma: A Report From the Children's Oncology Group and the LEOPARD Study.

PURPOSE: Identification of discrete risk groups remains a high priority for patients with Ewing sarcoma (EWS). We sought to prospectively validate circulating tumor DNA (ctDNA) as a prognostic factor and develop clinical-molecular risk groups. METHODS: We conducted a prospective investigator-initiated biology study for patients with localized EWS (LEOPARD) and embedded ctDNA analysis into the North American frontline metastatic study AEWS1221. Eligible patients were younger than 50 years with newly diagnosed EWS. All patients provided a baseline blood sample for analysis, which was subjected to ultralow-pass whole-genome sequencing and hybrid capture panel sequencing for ctDNA quantification, fusion detection, and characterization of STAG2 and TP53 alterations. Serial ctDNA sequencing was conducted on a subset of patients in each study. We tested for associations between ctDNA burden and secondary genomic events, and clinical features and outcomes. RESULTS: One hundred forty patients with localized disease and 255 with metastatic disease provided evaluable pretreatment samples for ctDNA analysis. Elevated baseline ctDNA was associated with stage, tumor size, primary site, indeterminate pulmonary nodules, and metastatic pattern. Elevated pretreatment ctDNA burden was associated with inferior outcomes in patients with localized (n = 140, hazard ratio [HR] = 2.36, P = .032) and metastatic disease (n = 255, HR = 2.15, P = .001). Patients with metastatic disease and TP53 variants and/or persistent on-therapy ctDNA had dismal outcomes. Patients with localized disease, low ctDNA, small tumors, and favorable genomics had no events and constitute a novel low-risk group. Among patients with metastatic disease, those with lung-only disease, low ctDNA, and favorable genomics represent an intermediate-risk group. CONCLUSION: This study prospectively validates pretreatment ctDNA burden as prognostic in EWS. Risk groups that integrate ctDNA burden with clinical-molecular features differentiate patients with low-, intermediate-, and high-risk disease.

Journal Article↗

Nuclear and chloroplast DNA differentiation in Andean potatoes.

Over 3500 accessions of Andean landraces have been known in potato, classified into 7 cultivated species ranging from 2x to 5x (Hawkes 1990). Chloroplast DNA (ctDNA), distinguished into T, W, C, S, and A types, showed extensive overlaps in their frequencies among cultivated species and between cultivated and putative ancestral wild species. In this study, 76 accessions of cultivated and 19 accessions of wild species were evaluated for ctDNA types and examined by ctDNA high-resolution markers (ctDNA microsatellites and H3 marker) and nuclear DNA restriction fragment length polymorphisms (RFLPs). ctDNA high-resolution markers identified 25 different ctDNA haplotypes. The S- and A-type ctDNAs were discriminated as unique haplotypes from 12 haplotypes having C-type ctDNA and T-type ctDNA from 10 haplotypes having W-type ctDNA. Differences among ctDNA types were strongly correlated with those of ctDNA high-resolution markers (r = 0.822). Differentiation between W-type ctDNA and C-, S-, and A-type ctDNAs was supported by nDNA RFLPs in most species except for those of recent or immediate hybrid origin. However, differentiation among C-, S-, and A-type ctDNAs was not clearly supported by nDNA RFLPs, suggesting that frequent genetic exchange occurred among them and (or) they shared the same gene pool owing to common ancestry.

DNA Primers↗

Neoadjuvant Paclitaxel, Trastuzumab, and Pertuzumab for Stage II to III, ERBB2-Positive Breast Cancer: A Secondary Analysis of the DAPHNe Trial.

IMPORTANCE: The neoadjuvant combination of paclitaxel, trastuzumab, and pertuzumab (THP) represents a promising abbreviated regimen for early-stage ERBB2-positive breast cancer, but long-term outcomes and the role of ultrasensitive circulating tumor DNA (ctDNA) monitoring remain incompletely defined. OBJECTIVE: To assess 5-year outcomes and characterize ctDNA dynamics with an ultrasensitive assay in patients with ERBB2-positive breast cancer receiving neoadjuvant THP. DESIGN, SETTING, AND PARTICIPANTS: This study was a prespecified secondary analysis of the prospective, single-arm, investigator-initiated phase 2 DAPHNe nonrandomized clinical trial. Patients were enrolled in the DAPHNe trial from November 2018 to January 2020. The trial took place at a multicenter academic cancer center and affiliated community practices. Participants included patients with stage II to III ERBB2-positive breast cancer receiving neoadjuvant THP for 12 weeks. Ultrasensitive ctDNA analyses were performed in patients with available tumor tissue and serial plasma samples. The secondary analysis was conducted between between March 2023 and April 2025. INTERVENTIONS: Neoadjuvant THP administered for 12 weeks, followed by surgery and adjuvant therapy guided by pathologic response. MAIN OUTCOMES AND MEASURES: Main outcomes included 5-year event-free survival, recurrence-free interval (RFI), distant RFI, and overall survival. ctDNA detection and clearance were assessed using a whole-genome-based, tumor-informed ultrasensitive assay at 4 predefined time points (baseline, preoperative, postoperative, and late adjuvant). RESULTS: The overall trial cohort included 98 patients (median [IQR] age, 49.5 years [24.0-78.0 years]; 97 female patients [99.0%]; 1 male patient [1.0%]), with mostly stage 2 disease (91 patients [92.9%]) and hormone receptor-positive tumors (65 patients [66.3%]). With a median (IQR) follow-up of 5.2 (5.0-5.4) years, the 5-year event-free survival was 99% (95% CI, 97%-100%), the 5-year RFI was 98% (95% CI, 93%-100%), the 5-year distant RFI was 100% (95% CI, 100%-100%), and the 5-year overall survival was 99% (95% CI, 97%-100%). Among 57 patients included in ctDNA analyses, baseline ctDNA was detected in 51 individuals (89.5%). After neoadjuvant therapy, ctDNA clearance occurred in 49 of 51 patients (96.1%), with only 2 individuals (3.9%) remaining ctDNA-positive preoperatively; detectability remained low (<10%) during postoperative follow-up. One single patient experienced a local recurrence, with ctDNA detected at time of recurrence and cleared following surgical resection. CONCLUSIONS AND RELEVANCE: In this secondary analysis of the DAPHNe nonrandomized clinical trial, neoadjuvant THP was associated with excellent long-term outcomes in patients with early-stage ERBB2-positive breast cancer. Ultrasensitive ctDNA analyses demonstrated high baseline detection rates and near-universal clearance after abbreviated neoadjuvant therapy, supporting further investigation of ctDNA-guided de-escalation strategies in this setting. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03716180.

Humans↗

Prognostic Value of Circulating Tumor DNA-Based Minimal Residual Disease for Recurrence-Free Survival in Resectable Gastric Cancer: A Systematic Review and Meta-Analysis with Serial Monitoring Analysis.

BACKGROUND: Circulating tumor DNA (ctDNA)-based minimal residual disease (MRD) is an emerging biomarker, but its utility in resectable gastric cancer remains incompletely characterized. METHODS: We conducted a systematic review and meta-analysis of eight studies (520 patients) to evaluate the prognostic value of ctDNA-based MRD for recurrence-free survival (RFS) and overall survival (OS) in resectable gastric cancer. RESULTS: In localized resectable gastric cancer (Stage I-III), the setting in which postoperative ctDNA most coherently represents true molecular residual disease after curative-intent surgery, postoperative ctDNA positivity was associated with diminished recurrence-free survival (RFS: HR 12.26, 95% CI 3.30-45.52) and overall survival (OS: HR 8.57, 95% CI 3.06-23.98). The test for subgroup differences between localized and mixed-stage cohorts was not statistically significant (P&#x2009;=&#x2009;0.57), and the numerically higher HR in the localized subgroup should therefore not be interpreted as evidence of a quantitatively stronger prognostic effect. Postoperative ctDNA detection demonstrated substantially stronger prognostic value (overall RFS: HR 10.00, 95% CI 4.53-22.10) compared to preoperative assessment (HR 2.17, 95% CI 1.10-4.28). Both tumor-informed and tumor-agnostic strategies effectively stratified high-risk patients. However, these effect sizes should be interpreted cautiously given the small number of studies and substantial heterogeneity (I2&#x2009;=&#x2009;65-72%). Results from mixed-stage cohorts including Stage IV disease are supportive but should not be considered equivalent to localized-disease findings, as ctDNA in metastatic disease reflects persistent systemic burden rather than minimal residual disease in the postoperative sense. CONCLUSIONS: Postoperative ctDNA-based MRD shows a consistent adverse prognostic association in resectable gastric cancer, with localized disease (Stage I-III) representing the most biologically and clinically coherent setting for interpretation. However, the large pooled hazard ratios (HR 10.00-12.26) should be interpreted as a directionally consistent signal rather than precise quantitative estimates, given the small number of studies, wide confidence intervals, and substantial heterogeneity (I2&#x2009;=&#x2009;65-73%). This heterogeneity is largely driven by substantial variation in postoperative sampling timing (4&#xa0;days to 16&#xa0;weeks) and ctDNA assay characteristics (platform, sensitivity, coverage, variant filtering, and positivity thresholds), which require standardization in future studies. While ctDNA is prognostically valuable, its clinical utility remains unestablished. Prospective randomized trials are needed to determine whether ctDNA-guided strategies improve patient outcomes before routine clinical implementation can be recommended.

Humans↗

Prospective Evaluation of Circulating Tumor DNA in Metastatic Hormone-Sensitive Prostate Cancer.

PURPOSE: There are few established prognostic biomarkers in metastatic hormone-sensitive prostate cancer (mHSPC). Disease volume and timing of metastases are prognostic and predictive factors but may be inadequate due to heterogeneity. Circulating tumor DNA (ctDNA) provides both circulating volume (tumor fraction [TF]) and genomic data. There are limited data on ctDNA in mHSPC. METHODS: This was a multicenter, prospective study of ctDNA testing in mHSPC. Presented here are the results before androgen-deprivation therapy initiation. The primary objective was to evaluate the association between TF and overall survival (OS) and time to mCRPC (TTCRPC). Secondary analyses included evaluating outcomes in subgroups of interest and key genomic subtypes. RESULTS: Between 2018 and 2024, 85 patients were enrolled, of whom 72 (25% Black) had evaluable baseline ctDNA samples and are included herein. Baseline TF was positive in 46 patients (64%). Compared with patients with negative ctDNA TF, most patients with positive ctDNA TF had de novo (87% v 39%, P < .001) and high-volume disease (80% v 46%, P = .01). At a median follow-up of 20.8 months, median OS was not reached (NR) with those with negative ctDNA TF and 33 months with positive ctDNA TF (hazard ratio [HR], 3.33 [95% CI, 1.1 to 9.9]; P = .03). However, a negative TF at baseline was associated with an undetectable 7-month prostate-specific antigen, a validated OS surrogate. Median TTCRPC was NR versus 13 months (HR, 3.43 [95% CI, 1.5 to 7.9]; P = .004). ctDNA TF was also potentially prognostic in high-volume disease and those who received doublet therapy. CONCLUSION: In this diverse cohort, a positive ctDNA TF at baseline was associated with worse outcomes in mHSPC and may potentially complement current further risk stratification tools.

Humans↗

Molecular residual disease assessment in colorectal and bladder cancer by somatic structural variant analysis of cell-free DNA whole-genome sequencing data.

BACKGROUND: Whole-genome sequencing (WGS)-based methods for circulating tumor DNA (ctDNA) detection typically rely on tumor-informed identification of somatic single nucleotide variants (SNVs). Somatic structural variants (SVs) are another type of cancer-specific genomic alteration, which owing to their larger genomic footprint and unique breakpoint junctions, are easier to distinguish from sequencing noise than SNVs. They are, however, rarely used for ctDNA detection because of (1) artifacts from WGS procedures that SV callers may falsely interpret as genuine SVs. This makes it difficult to establish high-confidence SV catalogos from short-read tumor WGS and can cause false-positive ctDNA detections. (2) Lack of robust strategies to quantify SV-supporting reads in plasma WGS. To address these barriers and enable integration of SV biomarkers into WGS-based ctDNA detection, we present a bioinformatic framework for algorithmic curation of somatic SV calls from fresh-frozen and formalin-fixed paraffin-embedded (FFPE) tumors, coupled with a novel approach for sensitive, accurate mapping and quantification of SV breakpoint-supporting reads in plasma WGS. METHODS: Tumor, normal and plasma WGS data from 144 patients with stage III colorectal cancer was used to establish the bioinformatic framework. This included ~30x WGS data from 1564 serially collected plasma samples. The framework was validated using tumor/normal/plasma WGS data from 32 patients with muscle-invasive bladder cancer. SV-based ctDNA detection was benchmarked against previously published SNV-based ctDNA results for the same samples. RESULTS: After curation of SV calls and quantification in plasma WGS, our SV-based approach enabled robust ctDNA detection with overall specificity exceeding 99% in plasma samples. Furthermore, we observed strong concordance (Pearson&#x2019;s r&#x2009;>&#x2009;0.93, p&#x2009;<&#x2009;2.2&#x2009;&#xd7;&#x2009;10&#x2212; 16) between ctDNA-positive samples identified by our SV-based method and previous SNV-based analyses, validating the reliability of our approach. Finally, we demonstrated application of the method in an independent bladder cancer cohort, highlighting its generalizability and potential clinical use. CONCLUSIONS: We provide a bioinformatic framework that establishes somatic SVs as ultra-specific biomarkers for WGS-based, tumor-informed ctDNA detection. The approach delivers specific detection even when the SV catalogos are established from FFPE samples. The SV framework can stand alone or enhance SNV-based analysis pipelines.

Humans↗

The molecular size and conformation of the chloroplast DNA from higher plants.

Covalently closed circular choloroplast DNA (ctDNA) molecules have been isolated from pea, bean, spinach, lettuce, corn and oat plants by ethidium bromide/cesium choloride density-gradient entrifugation. As much as 30-40% of the total ctDNA could be isolated as closed circular DNA molecules and up to 80% of the total ctDNA was found in the form of circular molecules. The size of pea, spinach, lettuce, corn and oat ctDNA relative to an internal standard (phiX174 replicative form II monomer DNA) was determined by electron microscopy. The ctDNAs showed significant differences in their sizes, and their molecular weights ranged from 85.4 - 10(6) for corn ctDNA to 96.7 - 10(6) for lettuce ctDNA. Each of these ctDNAs contained 3-4% of the circular molecules as circular dimers and 1-2% of the circular molecules as catenated dimes. The molecular complexity of these ctDNAs was studied by renaturation kinetics using T4 DNA as a standard. The molecular weights of the unique sequences of the ctDNAs ranged from 83.7 - 10(6) for oat ctDNA to 93.1 - 10(6) for lettuce ctDNA, which are in excellent agreement with the sizes of the circular ctDNA molecules...

Chloroplasts↗

Transfer ribonucleic acid genes in the chloroplast deoxyribonucleic acid of pea leaves.

The saturation hybridization between pea ctDNA and 125I-labeled pea ct-tRNAs has shown that 1.2% of the peak ctDNA codes for tRNA genes. The observed level of hybridization has been found to result from specific base pairings between ctDNA and ct-RNA as shown by competition hybridization experiments and thermal stability studies on DNA-tRNA hybrids. The level of hybridization obtained in this study amounts to the presence of approximately 40 tRNA genes in pea ctDNA. The tRNAs from the cytoplasm of the pea leaves, Escherichia coli, yeast, and calf thymus did not compete with the pea ct-tRNAs for the common base sequences in pea ctDNA. The presence of 17 aminoacyl-tRNA synthetases and their corresponding tRNAs was demonstrated in chloroplast. The acylation of ct-tRNAs proceeds with the same rate whether the partially purified tRNA synthetases from chloroplasts of E. coli are used. The aminoacylation of the three amino acids glutamic acid, glutamine, and cysteine proceeded very slowly in chloroplasts. The individually labeled aminoacyl-tRNAs hybridized with pea ctDNA. The hybridization follows true saturation rates, and the melting profiles of aminoacyl-tRNA-ctDNA indicate the formation of specific base pairs between the ctDNA and tRNA. Seventeen aminoacyl-tRNA genes have been identified in the pea ctDNA.

Chloroplasts↗

Evaluating the analytical validity of circulating tumor DNA sequencing assays for precision oncology.

Circulating tumor DNA (ctDNA) sequencing is being rapidly adopted in precision oncology, but the accuracy, sensitivity and reproducibility of ctDNA assays is poorly understood. Here we report the findings of a multi-site, cross-platform evaluation of the analytical performance of five industry-leading ctDNA assays. We evaluated each stage of the ctDNA sequencing workflow with simulations, synthetic DNA spike-in experiments and proficiency testing on standardized, cell-line-derived reference samples. Above 0.5% variant allele frequency, ctDNA mutations were detected with high sensitivity, precision and reproducibility by all five assays, whereas, below this limit, detection became unreliable and varied widely between assays, especially when input material was limited. Missed mutations (false negatives) were more common than erroneous candidates (false positives), indicating that the reliable sampling of rare ctDNA fragments is the key challenge for ctDNA assays. This comprehensive evaluation of the analytical performance of ctDNA assays serves to inform best practice guidelines and provides a resource for precision oncology.

Circulating Tumor DNA↗

Mutant KRAS in Circulating Tumor DNA as a Biomarker in Localized Pancreatic Cancer Patients Treated With Neoadjuvant Chemotherapy.

OBJECTIVE: The primary objective was to determine the prognostic significance of circulating tumor DNA (ctDNA) in patients receiving neoadjuvant chemotherapy (NAC) for localized pancreatic ductal adenocarcinoma (PDAC) using digital droplet polymerase chain reaction (ddPCR). BACKGROUND: Increasingly, ctDNA is being used for clinical decision-making in a variety of solid malignancies. However, the detection and prognostic value of KRAS ctDNA as assessed by ddPCR during NAC for PDAC has yet to be characterized. METHODS: Patients with localized PDAC eligible to receive NAC were prospectively enrolled. Peripheral blood samples were obtained at diagnosis, after NAC, and after resection and analyzed for ctDNA using ddPCR. Log-rank tests and Cox proportional hazards model were used to assess for associations with OS. RESULTS: Eighty-four patients were included in the analysis. Mutant KRAS ctDNA was detected in 49.3% of patients at diagnosis, 69.6% of patients after NAC, and 69.7% of patients after resection, respectively. There were 15 (17.9%) patients who cleared mutational ctDNA over the course of treatment. Clearance of ctDNA during NAC was associated with improved overall survival (OS) (18.4&#xa0;mo. vs NR, P <0.05). Detection of mutant KRAS G12V after NAC and resection was associated with shorter OS (18.0&#xa0;mo vs NR, P <0.031). Detection of the KRAS G12V mutation after resection was associated with reduced OS (aHR 36.75, 95% CI: 2.93-461.38). CONCLUSIONS: Throughout treatment, KRAS ctDNA is detectable by ddPCR in patients with localized PDAC treated with NAC. Detection of mutant KRAS G12V after resection was associated with reduced OS.

Humans↗

Clinical Relevance of Post-Treatment Circulating Tumor DNA Detection in Early Breast Cancer Using a Tissue-Free Epigenomic Assay: A 2-Year Landmark Analysis.

PURPOSE: Circulating tumor DNA (ctDNA) may serve as a biomarker to facilitate early identification of asymptomatic distant tumor spread in patients with breast cancer. The primary objective of this study was to assess clinical validity and prognostic value of post-treatment tissue-free ctDNA detection by evaluating its sensitivity for distant metastatic recurrence and its association with long-term outcomes. PATIENTS AND METHODS: Plasma samples were prospectively collected from patients with stage I-III early breast cancer who participated in the adjuvant SUCCESS-A phase III clinical trial (ClinicalTrials.gov identifier: NCT02181101). In this study, plasma samples collected approximately 2 years after completion of adjuvant chemotherapy from 313 SUCCESS A patients without evidence of prior disease recurrence were retrospectively analyzed using a tissue-free epigenomic ctDNA assay (Guardant Reveal). Survival analyses were performed using a landmark approach based on the time of sample collection. RESULTS: Overall, ctDNA was detected in 18 of 313 samples (5.8%). Of all ctDNA detected samples, 94% (17/18) were from patients who subsequently developed a distant recurrence, with ctDNA detected at a median interval of 7.9 months before recurrence. ctDNA positivity was strongly associated with a significantly shorter distant recurrence-free interval (hazard ratio [HR], 33.3 [95% CI, 4.12 to 268]; P < .0001) and poorer overall survival (HR, 27.3 [95% CI, 1.15 to 647]; P < .0001). The sensitivity for distant recurrence in patients who had a sample collected within 1 year before recurrence was 73% (11/15). The specificity in nonrecurred patients was 99.6% (267/268). CONCLUSION: Tissue-free detection of ctDNA 2 years after adjuvant chemotherapy was highly prognostic in an early-stage breast cancer cohort, and can be used to stratify patients with early-stage breast cancer at high risk for recurrence during follow-up who may benefit from early interventions.

Humans↗

Circulating Tumor DNA in Bladder Cancer: Current Clinical Evidence and Emerging Multi-Omics Perspectives-A Narrative Review.

Background: Circulating tumor DNA (ctDNA) analysis has emerged as a promising tool for real-time disease monitoring in muscle-invasive bladder cancer (MIBC). This narrative review summarizes current clinical evidence regarding ctDNA across disease stages. Methods: We examine recent translational and clinical findings, incorporating key prospective data from practice-changing trials, as well as insights into minimal residual disease (MRD) detection, treatment escalation and de-escalation strategies, and systemic barriers to adoption. Results: Postoperative ctDNA positivity consistently identifies patients with molecular residual disease (MRD) who face a substantially higher risk of recurrence and mortality, frequently preceding radiographic relapse by several months. Prospective evidence now validates ctDNA as a predictive biomarker to guide adjuvant immunotherapy escalation, while sustained ctDNA negativity correlates with high long-term disease-free survival. Beyond plasma ctDNA, emerging multi-compartment liquid biopsies-integrating urinary tumor DNA (utDNA)-demonstrate enhanced sensitivity, particularly in bladder-sparing and local surveillance settings. Furthermore, integrating genomic ctDNA profiling with novel post-transcriptional layers like epitranscriptomics offers a functional framework to capture tumor adaptation under therapeutic pressure. However, clinical translation remains constrained by a lack of assay harmonization, variable analytical sensitivity, and the need for standardized intervention thresholds. Conclusions: Longitudinal liquid biopsies are rapidly shifting MIBC management from static, stage-based paradigms toward dynamic, molecularly informed precision oncology. While ctDNA-guided strategies show robust clinical utility, prospective interventional validation and technical standardization are required before widespread routine integration.

biomarkers↗

Presence of displacement loops in the covalently closed circular chloroplast deoxyribonucleic acid from higher plants.

Chloroplast DNAs (ctDNA) from pea and corn plants were examined in the electron microscope for the presence of replicative intermediates. Pea and corn ctDNAs were each found to contain two displacement loops (D-loops). The D-loops were 820 (+/- 90) base pairs long in pea ctDNA and 860 (+/- 125) base pairs long in corn ctDNA. In each ctDNA, the two D-loops were located at positions that were 7100 +/- 240) base pairs apart. The displacing strands of the two D-loops were located on opposite strands of the parental DNA molecule and they were seen to expand toward each other. The D-loops in the ctDNA from pea and corn exhibited branch migration and thus were easily distinguished from the denatured regions that were also present in these closed circular ctDNAs. In addition, the positions of the D-loops were found to be distinct from the positions of the denaturation loops (Den-loops). The Den-loops were also shown to be located at AT-rich regions in these ctDNA molecules. D-loops and Den-loops were also found in the circular and catenated ctDNA oligomers from pea and corn plants. Mapping the positions of the D-loops relative to the positions of the Den-loops showed that the structure of the D-loop-containing region in the pea and corn ctDNAs has been conserved to a greater extent than the structure of the rest of the two ctDNA molecules.

Binding Sites↗

Longitudinal analysis of circulating tumor DNA and CA19-9 dynamics in predicting disease relapse and monitoring treatment response in stage I-III pancreatic ductal adenocarcinoma: An interim analysis of a prospective observational study.

INTRODUCTION: Postoperative recurrence is the leading cause of mortality in resected pancreatic ductal adenocarcinoma (PDAC), yet reliable tools for early relapse detection and treatment response assessment remain lacking. METHODS: In a prospective cohort of 136 patients with resected stage I-III PDAC receiving adjuvant chemotherapy, we evaluated circulating tumor DNA (ctDNA) and CA19-9 as longitudinal biomarkers across multiple postoperative time windows. RESULTS: ctDNA consistently outperformed CA19-9 as an independent prognostic factor; ctDNA positivity at on-treatment and surveillance assessments achieved a positive predictive value of 91.7%, while persistent negativity identified the lowest-risk patients. Integrating CA19-9 with ctDNA resolved the ctDNA-alone gap in distinguishing treatment clearance from conversion, improving discrimination of responders from non-responders (HR 3.72; P&#x202f;=&#x202f;.008). A time-weighted dynamic ctDNA risk score (MinerVa-dynamic) further stratified ctDNA-negative patients into clinically distinct prognostic subgroups, achieving an area under the curve of 0.87 and 0.82 for one- and two-year disease-free survival prediction, respectively. CONCLUSIONS: These findings support a dual-biomarker longitudinal monitoring framework as a practical, individualized approach to postoperative surveillance and early therapeutic decision-making in PDAC.

CA19-9↗

Identification of candidate variants in plasma associated with early versus late disease progression under anti-PD-1 therapy in metastatic NSCLC.

BACKGROUND: Immune checkpoint inhibitors (ICIs), including anti-programmed cell death protein 1 (anti-PD-1) antibodies, have significantly improved outcomes in patients with metastatic non-small cell lung cancer (mNSCLC). However, substantial heterogeneity exists in clinical benefit, with some patients exhibiting early progression (EP) and others late progression (LP). To date, no biomarkers of EP versus LP disease have been implemented in clinical practice. Circulating tumor DNA (ctDNA) analysis represents a minimally invasive strategy for identifying such biomarkers. In this proof-of-concept study, we evaluated the performance of the TruSight Oncology 500 ctDNA (TSO500 ctDNA) panel and explored its feasibility to identify candidate variants associated with early and late disease progression under anti-PD-1 therapy. METHODS: Baseline ctDNA from eight mNSCLC patients treated with pembrolizumab was extracted and sequenced using the TSO500 ctDNA assay, a 523-gene targeted next-generation sequencing panel. Patients were classified according to their response as LP or EP. Variant calling was performed using the DRAGEN Bio-IT platform, and variants were annotated and clinically interpreted using the Clinical Genomics Workspace (CGW; PierianDx) according to Association for Molecular Pathology (AMP)/American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines. Survival outcomes were assessed using Kaplan-Meier and log-rank tests. Performance of ctDNA variants was evaluated using receiver operating characteristic (ROC) curve analysis, and multi-gene models were assessed using leave-one-out cross-validation with penalized logistic regression. RESULTS: All patients harbored detectable variants, including SNVs (100%), MNVs (87.5%), deletions (75%), and insertions (62.5%). Tier I variants were identified in 37.5% of patients, while all cases showed tier II and multiple tier III alterations. TP53 variants were associated with poorer outcomes under anti-PD-1 therapy. Individual gene alterations in TP53, ERBB3, SMC1A or LATS1 showed moderate discriminatory performance between LP and EP patients; however, combination of mutated genes improved apparent discrimination. Notably, specific two-gene combinations (SMC1A + LATS1 or ERBB3 + LATS1) showed the highest discriminatory performance between LP and EP patients in this exploratory cohort. CONCLUSIONS: This study demonstrates the feasibility and analytical performance of the TSO500 ctDNA panel and provides hypothesis-generating evidence that plasma gene variants may be useful to evaluate early versus late disease progression in patients with mNSCLC receiving immunotherapy.

TruSight Oncology 500↗

Eribulin versus taxane as first-line chemotherapy combined with dual HER2 blockade in patients with HER2-positive locally advanced or metastatic breast cancer: final survival outcomes of the JBCRG-M06/EMERALD study.

BACKGROUND: The phase III JBCRG-M06/EMERALD study was the first to show noninferior progression-free survival (PFS) of eribulin to taxane, combined with dual human epidermal growth factor receptor 2 (HER2) blockade (trastuzumab plus pertuzumab), as a first-line treatment for HER2-positive locally advanced breast cancer or metastatic breast cancer (LABC/MBC). We report final survival outcomes and biomarker analyses of the EMERALD trial. PATIENTS AND METHODS: Patients with HER2-positive LABC/MBC were randomly assigned 1:1 to either eribulin or physician-choice taxane (docetaxel or paclitaxel), both combined with trastuzumab plus pertuzumab, as first-line chemotherapy. PFS and overall survival (OS) were assessed through 30 June 2023 for PFS and 31 December 2024 for OS. Survival outcomes were compared between the eribulin and taxane groups and according to circulating tumor DNA (ctDNA) detection of PIK3CA mutations (PIK3CAm+; E542K, E545K, H1047R, and N345K single nucleotide variants) or HER2 amplification (HER2 amp+; ERBB2 copy number >2.5). RESULTS: Median OS was 78.5 months [95% confidence interval (CI) 64.3-not reached (NR)] for eribulin and was NR for taxane, with a hazard ratio of 1.25 (95% CI 0.92-1.71, log-rank P = 0.19). The 60-month OS rates were 59.7% and 65.2% for eribulin and taxane, respectively. Median OS and 60-month OS rates were numerically lower in ctDNA PIK3CAm+ patients, and greater in ctDNA HER2 amp+ patients for all patients and with stratification by treatment group. There were no statistical interactions between treatment group with either ctDNA PIK3CAm or ctDNA HER2 amp status. Similar patterns were observed for PFS. CONCLUSION: Final survival analysis revealed that median OS exceeded 6 years with eribulin or physician-choice taxane, combined with trastuzumab plus pertuzumab, as first-line chemotherapy for HER2-positive LABC/MBC, with no significant differences between the two groups. ctDNA PIK3CAm+ status was a poor prognostic factor. ctDNA HER2 amp+ was associated with longer survival.

Aged↗

Cationic porphyrins bearing diazolium rings: synthesis and their interaction with calf thymus DNA.

Two novel cationic porphyrins bearing five-membered rings at the meso-positions, meso-tetrakis(1,3-dimethylimidazolium-2-yl)porphyrin (H2TDMImP) and meso-tetrakis(1,2-dimethylpyrazolium-4-yl)porphyrin (H2TDMPzP), have been synthesized. These two compounds interact with calf thymus DNA (CTDNA) in different binding modes from that of mesotetrakis(N-methylpyridinium-4-yl)porphyrin (H2TMPyP). H2TDMImP outside binds to the minor groove of CTDNA while H2TDMPzP intercalates into CTDNA. These two novel cationic porphyrins strongly bind to CTDNA even at high ionic strength and the binding constant of H2TDMPzP to CTDNA is comparable to that of H2TMPyP. The binding of H2TDMImP to CTDNA is enthalpically driven. The favorable free energy changes in binding of H2TDMPzP to CTDNA come from the large negative enthalpy changes accompanied by small positive entropy changes.

Animals↗

Baseline Plasma Cell-Free and Circulating Tumor DNA Across Lymphoma Subtypes and Its Prognostic Impact in Diffuse Large B-Cell Lymphoma.

BACKGROUND: Circulating tumor DNA (ctDNA) analysis enables real&#x2011;time assessment of the tumor burden and genomic complexity in lymphomas. However, real&#x2011;world evidence across lymphoma subtypes is limited. METHODS: We analyzed cell&#x2011;free DNA (cfDNA) and ctDNA data from 336 consecutive patients with newly diagnosed Hodgkin or non-Hodgkin lymphoma in 2022 and evaluated their prognostic impact in diffuse large B&#x2011;cell lymphoma (DLBCL). RESULTS: We detected somatic alterations in 248 of 336 patients (73.8%). DLBCL and follicular lymphoma showed the highest variant prevalences and ctDNA burdens. Epigenetic regulators, including KMT2D, CREBBP, TET2, and HIST1H1E, constituted the dominant class of genes with recurrent alterations. Plasma variant profiles closely mirrored publicly available, tissue&#x2011;based next-generation sequencing datasets. The baseline ctDNA burden correlated with adverse clinical features, and ctDNA positivity was associated with failure to achieve complete remission. In DLBCL, elevated cfDNA (top quartile) and a high International Prognostic Index (IPI) were independently associated with shorter overall and progression&#x2011;free survival. However, the total variant count per patient was not significantly associated with survival after adjustment. CONCLUSIONS: Baseline plasma cfDNA and ctDNA assessments are feasible in routine practice and recapitulate tissue-variant landscapes. Elevated cfDNA concentrations-but not the total variant count-were independently associated with survival in DLBCL, providing prognostic information beyond the IPI and supporting integration of plasma-based biomarkers into multiparameter risk models. Gene&#x2011;level ctDNA associations should be regarded as exploratory and hypothesis&#x2011;generating.

Cell-free DNA↗