Search Results (263)

Despite advances in systemic therapy, many early breast cancer patients experience recurrence due to subclinical minimal residual disease (MRD). Circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs) have emerged as promising liquid biopsy markers for post-treatment MRD detection. This pre-registered systematic review and meta-analysis (PROSPERO/PRISMA 2020) evaluated their comparative prognostic significance. Seven databases were searched from inception to March 2026. Eligible studies included early breast cancer patients undergoing post-treatment ctDNA or CTC assessment after neoadjuvant or adjuvant therapy, reporting survival outcomes with extractable hazard ratios. Quality was assessed using the QUIPS tool; random-effects meta-analyses used the REML estimator. Seventeen studies (thirteen ctDNA, four CTCs; n = 3030) were included. Post-treatment CTC positivity was significantly associated with poorer survival (pooled HR = 2.99, 95% CI: 1.99–4.49; I² = 17.2%). ctDNA positivity demonstrated a substantially stronger prognostic effect (pooled HR = 10.28, 95% CI: 6.32–16.70; I² = 47.3%). Subgroup analyses identified assessment timing as a key heterogeneity source, with stronger effects after adjuvant (HR = 20.62; k = 4) versus neoadjuvant therapy (HR = 6.07; k = 9); given the small number of post-adjuvant studies, this finding is hypothesis-generating. No significant publication bias was detected. Both markers were significant prognostic markers of MRD. ctDNA showed a stronger pooled prognostic association, although no study assessed both biomarkers within the same cohort and direct head-to-head comparisons therefore remain lacking. Prospective randomized trials are needed to evaluate MRD-guided treatment strategies. Full article

Translational oncology has moved rapidly from histopathology and single-analyte biomarkers toward multi-dimensional molecular profiling. Yet many clinically deployed tests still use reductionist biomarker strategies that under-represent cancer complexity. This review examines whether a mechanistic, multi-layered, and specimen-aware approach can improve cancer detection, classification, prognosis, minimal residual disease (MRD) assessment, and therapeutic selection. Evidence across solid tumours shows that genomic alterations alone incompletely explain tumour state, metastatic behaviour, immune evasion, or therapeutic vulnerability. Integrated genome and transcriptome analyses, proteogenomics, single-cell atlases, fragmentomic, methylation based cell-free DNA assays, metabolomics and microbiome assessments reveal clinically relevant biology that single modality tests cannot determine. Minimally invasive collected specimens can extend access to screening, diagnosis and longitudinal monitoring, but the choice of specimen should be matched to disease biology and analytes that represent mechanisms of oncogenesis. However, translation remains constrained by pre-analytical variability, contamination, differences in tumour shedding behaviour, clonal haematopoiesis, translation of generated models, incomplete external validation and uncertain downstream clinical utility for emerging platforms. This review provides a commentary on the future of cancer diagnostics, the considerations and barriers to clinical translation, the relationship between utility and dimensionality of biomarkers assessed and the emerging rationale towards mechanistically grounded integrated models. Full article

Perioperative treatment for colorectal cancer (CRC) is undergoing a paradigm shift from uniform cytotoxic regimens toward strategies guided by tumor location, microsatellite instability (MSI)/mismatch repair (MMR) status, and recurrence risk. Four clinically relevant subgroups now shape decision-making: microsatellite stable (MSS)/proficient MMR (pMMR) colon cancer, microsatellite instability-high (MSI-H)/deficient MMR (dMMR) colon cancer, MSS/pMMR rectal cancer, and MSI-H/dMMR rectal cancer. In MSS/pMMR colon cancer, adjuvant therapy is being refined through risk-adapted treatment duration and selective use of neoadjuvant chemotherapy. In MSS/pMMR rectal cancer, total neoadjuvant therapy, selective omission of pelvic radiotherapy, and watch-and-wait strategies are redefining treatment sequencing and organ preservation. In MSI-H/dMMR colon cancer, immune checkpoint inhibitor (ICI) therapy has shown marked activity in both adjuvant and neoadjuvant settings. In MSI-H/dMMR rectal cancer, neoadjuvant ICI therapy is being explored as a non-operative organ preservation strategy. In parallel, circulating tumor DNA (ctDNA)-based minimal residual disease (MRD) assessment is emerging as a tool for postoperative escalation, de-escalation, and surveillance. Across these settings, the maturity of the evidence varies widely, ranging from established phase III standards to guideline-endorsed but still single-arm approaches and investigational strategies that require prospective validation before routine adoption. This review summarizes the current evidence and remaining challenges in biology-, site-, and risk-adapted perioperative management of CRC. Full article

Circulating tumor DNA (ctDNA) is a promising non-invasive biomarker for detecting minimal residual disease (MRD) and predicting recurrence after curative treatment, yet evidence in esophageal squamous cell carcinoma (ESCC), esophageal adenocarcinoma (EAC), and gastric cancer has largely been examined within individual tumor types. In this scoping review, we mapped this evidence across all three malignancies and clarified key methodological and clinical considerations. Following the PRISMA-ScR guidelines, we searched PubMed, Scopus, and the Cochrane Library (3 April 2026) for studies linking ctDNA to disease-free, recurrence-free, or overall survival after curative-intent treatment. Twenty-seven studies (1746 patients; 10 ESCC, 4 EAC, 8 gastric, and 5 mixed) were included. Across every tumor type, postoperative ctDNA MRD was the most informative timepoint, with independent multivariable hazard ratios for disease-free, recurrence-free, or event-free survival of 2.8 to 21.8, whereas preoperative ctDNA was seldom prognostic. Serial monitoring further improved performance and flagged recurrence 78 to 278 days before imaging. Tumor-informed assays showed higher sensitivity than tumor-agnostic ones (80% vs. 35%), though direct comparisons were limited; correction for clonal hematopoiesis was essential for tumor-agnostic assays, and blood-based assays performed poorly in diffuse-type and peritoneal disease. Postoperative ctDNA MRD is a consistent, independent prognostic biomarker across upper gastrointestinal cancers that adds prognostic information beyond conventional staging and pathological response, supporting prospective interventional trials of ctDNA-guided management. Full article

Endometrial and cervical cancers can recur from subclinical disease not evident on routine surveillance. This narrative review critically evaluates liquid biopsy for minimal residual disease (MRD) assessment and recurrence monitoring. Post-treatment human papillomavirus (HPV) circulating tumor DNA (ctDNA) in cervical cancer has the strongest disease-specific prospective evidence of clinical validity; persistent detection is strongly associated with recurrence, but moderate sensitivity and false-negative results do not support treatment de-escalation on negativity alone. With regard to endometrial cancer, perioperative ctDNA has prognostic support from an 11-study, 1298-patient meta-analysis and additional cohorts, although assay heterogeneity and limited independent replication constrain clinical readiness. Postoperative positivity generally shows stronger associations than preoperative detection. Cervicovaginal and urine DNA-methylation studies provide preliminary evidence for detecting established recurrence, especially local recurrence, but not prospective molecular lead time or clinical utility. Digital PCR, disease-specific fixed panels, tumor-informed assays, and error-corrected sequencing serve distinct settings; broad pan-cancer plasma profiling remains mainly an advanced-disease tool. Circulating tumor cells, extracellular vesicles, microRNAs, tumor-educated platelets, and fragmentomics remain exploratory. Liquid biopsy should remain an investigational adjunct until prospective trials show that acting on molecular findings improves outcomes. Full article

Background: Multiple myeloma (MM) is an incurable hematologic malignancy, and the majority of patients eventually relapse due to persistent myeloma cells. While minimal residual disease (MRD) reflects tumor burden, the host immune system also plays a crucial role in disease control. Our study aimed to evaluate MRD, complete blood count (CBC), and immune cell profiles in MM patients treated with bortezomib/adriamycin/dexamethasone (PAD) chemotherapy followed by autologous stem cell transplantation (ASCT) to determine their prognostic value and interplay. Objectives: This study aims to identify markers indicative of a favorable prognosis in MM patients. Methods: CBC data were collected from 93 MM patients at diagnosis, prior to ASCT, and 3 months post-ASCT. Immune cell profiles were assessed via flow cytometry using fresh peripheral blood samples from a subset of 33 prior to ASCT and 3 months post-ASCT. We subsequently investigated the associations between MRD status and prognosis, the predictive value of CBC, and the longitudinal changes in immune cell profiles and their correlation with clinical outcomes. Results: An increased frequency of negative immunomodulatory cell subsets and activated T lymphocytes prior to ASCT were associated with a poor prognosis. Conversely, lower levels of exhausted T lymphocytes, alongside higher levels of functional T cells and marginal zone B cells post-ASCT, predicted a favorable prognosis. Conclusions: Our study demonstrates that pre-ASCT immune status, post-ASCT immune reconstitution, and MRD status at 3 months post-ASCT are closely associated with clinical outcomes in MM patients. These findings underscore the critical importance of regular immune monitoring in the comprehensive management of MM. Full article

Immune checkpoint inhibitors (ICIs) are now being introduced into perioperative treatment for several solid tumors. This strategy is usually explained by tumor reduction before surgery or by the elimination of minimal residual disease (MRD) after surgery. However, these explanations may not be sufficient to understand why the timing of ICI treatment, especially before lymph node (LN) removal, is important. In this review, we discuss tumor-draining lymph nodes (tdLNs) from two different aspects. tdLNs are anatomical routes for regional and distant metastasis, but they are also sites where tumor antigens are presented and tumor-specific T cell responses are generated. In particular, preclinical and translational studies suggest that tdLNs may maintain stem-like or progenitor-exhausted T cells (TPEX) that can respond to PD-1 blockade and supply more differentiated exhausted T cells to tumor sites. However, current clinical trials of perioperative ICIs demonstrate therapeutic benefit in specific diseases and regimens, but do not directly establish tdLN preservation or tdLN-resident TPEX maintenance as the decisive mechanism of efficacy. We therefore present the tdLN-reservoir model as a hypothesis-generating framework rather than as a clinically validated basis for modifying lymph node management. We also discuss the possible roles of neoadjuvant and adjuvant ICI in relation to antigen flow, minimal residual disease, metastatic-site draining LNs, postoperative lymphatic dysfunction, and future immune-guided clinical trials. Importantly, current evidence does not support altering standard lymph node surgery or radiotherapy solely to preserve putative tdLN immune-reservoir function. Full article

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of aggressive non-Hodgkin lymphoma and is characterized by pronounced molecular heterogeneity that is not always fully captured by standard histopathological assessment. Circulating tumor DNA (ctDNA) is increasingly regarded as a promising liquid-biopsy biomarker that enables non-invasive molecular tumor profiling, assessment of tumor burden, dynamic monitoring of treatment response, and detection of measurable/minimal residual disease (MRD). Modern analytical platforms, ranging from PCR-based assays to next-generation sequencing approaches, including CAPP-Seq and PhasED-Seq, have substantially expanded the possibilities of molecular monitoring in DLBCL. This review summarizes current data on the biological characteristics of ctDNA, contemporary methods for its analysis, concordance between ctDNA and tumor-tissue mutational profiles, and the clinical significance of baseline ctDNA levels, early molecular response, post-treatment MRD status, and molecular surveillance during remission. Special attention is given to ctDNA monitoring in patients receiving novel immunotherapies, including CAR-T cell therapy, bispecific antibodies, and antibody–drug conjugates. Emerging multi-omic approaches integrating genomic, epigenomic, and fragmentomic data are discussed as promising future directions. Key limitations of clinical implementation include insufficient standardization of preanalytical and analytical workflows, the confounding effect of clonal hematopoiesis of indeterminate potential, variability across technological platforms, and the lack of completed prospective randomized interventional studies demonstrating improved outcomes when therapy is modified according to ctDNA status. Overall, ctDNA is currently a highly informative prognostic biomarker in DLBCL; however, its full implementation as a predictive tool for treatment selection requires further harmonization, prospective validation, and confirmation in interventional clinical trials. Full article

Background: Bone and soft-tissue sarcomas are rare, heterogeneous malignancies whose surveillance remains dominated by imaging despite substantial molecular diversity and variable patterns of relapse. Circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs) offer minimally invasive approaches for monitoring tumor biology, but their performance in sarcoma depends strongly on subtype, disease burden, assay design, and biological shedding. Methods: This narrative review synthesizes evidence published from 2015 to 2026 on ctDNA and CTCs for baseline risk assessment, treatment-response monitoring, minimal residual disease (MRD) detection, molecular relapse, and integration with imaging-based surveillance in bone and soft-tissue sarcomas. Results: Current evidence supports a genomics-guided framework in which liquid-biopsy strategy is selected according to sarcoma subtype, molecular architecture, and clinical purpose. ctDNA is the most mature analyte, with best-supported evidence in osteosarcoma, where tumor-informed assays predict postoperative relapse, and in translocation-associated sarcomas, where breakpoint-guided assays enable highly specific longitudinal monitoring. Copy-number-based approaches are relevant for complex-karyotype tumors, while mutation-, methylation-, fragmentomic-, and RNA-based strategies may be useful in selected contexts. However, detection rates vary, false-negative results occur in low-shedding or low-volume disease, and clinical utility for changing treatment remains incompletely established. CTCs provide complementary cellular and prognostic information, particularly in osteosarcoma, but remain limited by platform heterogeneity and incomplete standardization. Conclusion: Liquid biopsy may refine risk stratification, support treatment-response assessment, clarify indeterminate imaging findings, and identify molecular relapse in selected sarcoma patients. At present, it should be interpreted as an adjunct to imaging and specialist multidisciplinary care rather than as a replacement for standard radiologic surveillance. Full article

Background/Objectives: Multiple myeloma (MM) is a complex hematologic malignancy characterized by abnormal plasma cell proliferation in the bone marrow. [¹⁸F]FDG PET/CT has emerged as a key imaging modality, demonstrating high sensitivity and specificity for the detection of metabolically active disease compared with conventional imaging techniques. This review examines the role of PET/CT imaging in evaluating therapeutic response in symptomatic myeloma, including minimal residual disease (MRD) assessment. Methods: We surveyed the literature published between 2014 and 2024 across PubMed, Scopus, Web of Science, and the Cochrane Library for peer-reviewed articles evaluating PET imaging in the assessment of treatment response in multiple myeloma. Results: [¹⁸F]FDG PET/CT provides a whole-body assessment of disease burden, extramedullary involvement detection, and early metabolic response evaluation. Standardized response assessment criteria (Deauville, IMPeTUs, IMWG) have enhanced the reproducibility and accuracy of treatment monitoring. Semiquantitative parameters including SUVmax and metabolic tumor volume (MTV) provide useful prognostic information with PET negativity correlating with improved progression-free and overall survival. The integration of PET/CT with bone marrow assessment techniques (next-generation flow cytometry and sequencing) optimizes MRD evaluation and patient stratification. Conclusions: PET/CT represents a valuable imaging tool for improving therapeutic decision making and risk stratification in MM management. Emerging radiotracers beyond FDG, including [¹¹C]choline, [¹¹C]methionine, and targeted agents like [⁶⁸Ga]pentixafor and CD38-targeted immunoPET tracers, hold promise for enhanced diagnostic capabilities in specific clinical contexts. Full article

Background/Objectives: Merkel cell carcinoma (MCC) is a rare but aggressive skin cancer with a 40% recurrence rate. However, reliable biomarkers for early recurrence detection or treatment guidance are lacking, especially for virus-negative tumors. Circulating tumor DNA (ctDNA), a fragment of tumor-derived cell-free DNA in blood, has emerged across multiple cancers as a minimally invasive precision biomarker to detect minimal residual disease (MRD); predict recurrence; and monitor treatment response. This review’s objective was to summarize recent advances in ctDNA as a tool for therapeutic decision-making in MCC, contextualized by findings in other malignancies. Methods: A comprehensive literature review was performed, focusing on studies published between 2016 and 2026 that evaluate ctDNA in MCC and other cancers. Key prospective trials, observational studies, and case reports were identified through PubMed and relevant conference proceedings. Data on ctDNA assay methods (tumor-informed vs. tumor-agnostic), clinical sensitivity, lead time for recurrence detection, and predictive value for therapy response were extracted and synthesized. Results: Across cancers such as colorectal, lung, and melanoma, ctDNA positivity after curative treatment predicts relapse months in advance of imaging and can guide adjuvant therapy decisions. In MCC, recent studies demonstrate that ctDNA levels correlate with MCC tumor burden and exhibit high sensitivity and specificity for clinically evident disease. Stage I-III MCC patients who were ctDNA-positive within four months of treatment had a 7.4-fold higher recurrence risk within the subsequent 12–18 months of follow-up. Serial ctDNA monitoring may enable earlier intervention in otherwise asymptomatic ctDNA-positive MCC cases, helping distinguish responders from non-responders. Conclusions: ctDNA is an emerging precision biomarker that offers significant prognostic and surveillance utility in MCC. It enables earlier detection of recurrence, potentially allowing treatment to begin before clinical disease manifests. It also helps stratify patients by risk and treatment response, informing personalized surveillance intensity and therapeutic choices. Integrating ctDNA monitoring into MCC management could improve outcomes by guiding timely interventions, although prospective trials are needed to confirm that ctDNA-guided decisions translate to improved patient survival. Formal cost-effectiveness analyses have not yet been conducted and represent an important area for future investigation. Full article

Background: Pancreatic ductal adenocarcinoma (PDAC) exhibits high post-resection relapse and early systemic dissemination rates. The level of circulating tumor cells (CTCs) correlates with early metastatic failure, motivating CTC interception strategies. Methods: In this hypothesis-driven review, we synthesized the contemporary evidence on PDAC staging and therapy, CTC detection (including portal versus peripheral sampling), and circulating tumor DNA (ctDNA)-based minimal residual disease (MRD), and evaluated the translational rationale for CTC-targeted adoptive immunotherapy focusing on CEACAM6 and CAR-T cells. Results: Prospective studies report higher portal versus peripheral CTC yields and stronger associations with relapse; tumor-informed ctDNA positivity in peri-operative and surveillance windows predicts shorter disease-free survival. CEACAM6 is overexpressed in PDAC and linked to invasion and metastasis, supporting antigen selection. However, target overexpression alone does not establish clinical suitability for adoptive cell transfer. Consequently, its therapeutic implementation must contend with assay heterogeneity, on-target/off-tumor risks, and the lack of interventional outcome data in PDAC, all of which remain key hurdles. Conclusions: CTC-targeting is biologically plausible and operationally measurable in PDAC. Consequently, a CEACAM6-directed CAR-T approach is proposed as a potential strategy for the interception of minimal residual disease (MRD). Randomized and biomarker-selected trials with composite MRD-clearance endpoints (CTC < LOQ and ctDNA-negative) may be justified to validate this interventional hypothesis. Full article

Relapse remains the leading cause of treatment failure following hematopoietic cell transplantation (HCT) for hematologic malignancies. Circulating tumor DNA (ctDNA) has emerged as a promising minimally invasive biomarker for measurable residual disease (MRD) assessment and early relapse detection; however, the prognostic significance of ctDNA in the post-transplant setting has not been comprehensively synthesized. We conducted a systematic review and meta-analysis in accordance with PRISMA guidelines and registered the protocol in PROSPERO (CRD420261392100). PubMed, Embase, Web of Science, EBSCO, Cochrane CENTRAL, and supplementary sources were searched through November 2025. Eligible studies evaluated tumor-specific ctDNA or tumor-informed/tumor-associated cfDNA in patients undergoing allogeneic or autologous HCT for hematologic malignancies. Random-effects meta-analyses were performed for relapse/progression, overall survival (OS), and relapse-free/progression-free survival (RFS/PFS). Studies evaluating total cfDNA quantity, methylation-based cfDNA profiling, cfRNA, or chimerism-only monitoring were synthesized narratively. Ten observational cohort studies comprising 883 patients met inclusion criteria. Across acute leukemias, lymphomas, multiple myeloma, and myelodysplastic syndromes, ctDNA/cfDNA positivity was consistently associated with adverse outcomes. The pooled hazard ratio (HR) for relapse or disease progression was 12.57 (95% CI: 4.59–34.46; p < 0.001), while pooled HRs were 7.45 (95% CI: 4.11–13.48; p < 0.001) for OS and 4.46 (95% CI: 2.22–8.97; p < 0.001) for RFS/PFS. Although statistical heterogeneity was low, interpretation was limited by the relatively small number of studies contributing to each pooled endpoint. Narrative evidence additionally suggested that broader circulating nucleic acid approaches may provide complementary information regarding graft-versus-host disease, infection, and other post-transplant complications. Tumor-specific ctDNA positivity is consistently associated with increased relapse risk and inferior survival outcomes following HCT. These findings support further investigation of ctDNA-based MRD monitoring as a promising non-invasive biomarker for post-transplant molecular surveillance and risk stratification. However, prospective multicenter validation studies, assay standardization, and ctDNA-guided interventional trials remain necessary before routine clinical implementation can be recommended. Full article

Pancreatic ductal adenocarcinoma (PDAC) is the most complex and aggressive disease with the worst rates of unresectable or metastatic disease at diagnosis, resistance to systemic therapy, and case fatality rate (CFR) among leading cancers. In non-metastatic disease, neoadjuvant treatment with modern chemotherapeutic regimens followed by surgical resection and/or adjuvant mFOLFIRINOX has significantly improved oncological outcomes. However, recurrence rates remain alarmingly high, while immune checkpoint inhibitors (ICIs) or molecularly targeted therapy have not yet demonstrated clinical benefits. Comprehensive genomic profiling through NGS-based approved assays such as TruSight Oncology 500 (TSO500) could guide targeted therapy. Rapidly evolving mRNA cancer vaccines and circulating tumor DNA (ctDNA)-based prediction of minimal residual disease (MRD) and recurrence risk hold great promise towards the realization of rational combination therapy to improve recurrence-free survival (RFS) and overall survival (OS). More recently, single-cell multiomics (SC MO), spatial proteomics and transcriptomics (SPT), artificial intelligence (AI), and systems biology have revolutionized cancer research, enabling holistic tumor microenvironment (TME) analysis. In this comprehensive review, we describe the latest advances and unmet needs in the standard of care of PDAC. Moreover, we discuss the expectations of ongoing randomized clinical trials of adjuvant mRNA vaccine-based therapy and ctDNA MRD testing as prognostic biomarkers, towards personalized treatment to improve RFS and OS in a medium-term perspective. With a longer perspective, we explore how harnessing SC MO, SPT, AI, and systems biology can reveal the 3D spatial organization of interacting cancer, immune, and stromal cells. Multi-dimensional TME-, TSO500- and ctDNA-based framework of dynamic biomarkers are of paramount importance to achieve an optimal patient-specific perioperative multimodal treatment combining precision immunotherapy, targeted drugs, and modern chemotherapy, translated into future practice-changing clinical trials, that could eliminate MRD towards recurrence prevention. Full article

Therapeutic cancer vaccines represent a rational immunotherapeutic strategy aimed at inducing tumor-specific adaptive immune responses in patients with established malignancies. In contrast to prophylactic vaccines, these approaches must function within immunosuppressive tumor microenvironments characterized by antigenic heterogeneity, immune dysfunction, and dynamic tumor evolution. Effective vaccine design requires the integration of three essential components: the selection of appropriate tumor-associated or tumor-specific antigens, efficient delivery platforms that enable antigen presentation, and adjuvant systems that promote robust T-cell priming and expansion. Initial clinical investigations in B-cell malignancies and multiple myeloma demonstrated that idiotype-based vaccines can elicit tumor-specific immune responses. However, durable clinical benefit has been inconsistent, reflecting limitations in antigen selection, suboptimal immunogenicity, and tumor-mediated immune evasion. Over the past decade, advances in tumor genomics, next-generation sequencing, and immune monitoring have enabled the development of next-generation vaccine platforms, including dendritic cell-based approaches, personalized neoantigen vaccines, and mRNA-based technologies. Emerging evidence suggests that vaccine efficacy is highly dependent on disease context. Biologically favorable settings such as minimal residual disease (MRD) and post-transplant immune reconstitution provide reduced tumor burden and improved immune competence, thereby enhancing the likelihood of effective immune priming. In parallel, combination strategies incorporating immune checkpoint inhibitors, immunomodulatory agents, and cellular therapies are increasingly being explored to overcome tumor-induced immunosuppression. This review synthesizes current knowledge of therapeutic cancer vaccines in B-cell malignancies and multiple myeloma, with emphasis on immunologic mechanisms, antigen selection, vaccine platforms, and clinical evidence. We further propose a conceptual framework integrating tumor biology, immune context, and combination strategies to guide the rational development of next-generation vaccine therapies. Full article