Circulating Tumor DNA and Minimal Residual Disease (MRD) in Solid Tumors: Current Horizons and Future Perspectives

The global progress and quality assessment of research on the association between circulating tumor DNA and clinical prognosis: a systematic review

Objective

Circulating tumor DNA (ctDNA) has shown potential as a prognostic biomarker in patients with solid tumors. This study aimed to systematically summarize the global application of ctDNA in the prognostic management of solid tumor patients and to evaluate the quality of the current studies.

Methods

PubMed, Web of Science, Embase, Cochrane Library, Scopus, and clinical trials.gov databases were searched to collect cohort studies on ctDNA in the prognosis of solid tumor patients from January 2016 to May 2022. The language was limited to English. Information including general information, participants and cancer characteristics, ctDNA and outcome information were extracted. The quality of the studies was assessed using the Newcastle-Ottawa Scale checklist.

Results

A total of 214 studies were included in the final analysis, encompassing 21,076 patients. The number of studies has increased annually from 2016 to 2022. The most common types of solid tumors studied were colorectal cancer (27.10 %), lung cancer (20.09 %), pancreatic cancer (16.82 %), and breast cancer (14.02 %). The top three journals by number of publications had an impact factor in 2023 greater than 10. Of the studies, the median sample size was 69 (interquartile range: 41-111), 69.81 % had a sample size <100, 68.92 % had a median/mean age ≥60 years, and 74.05 % were from developed countries. Multi-center studies accounted for 40.36 %. Additionally, 29.82 % of the studies had a bias risk score ≤6. Only 16.67 % of studies on liver cancer had a bias risk score >6. The primary criteria not met by the studies included "Adequacy of follow-up of cohorts" (33.33 %), "Assessment of outcome" (32.16 %) and "Representativeness of the exposed cohort" (27.49 %).

Conclusions

The prognostic value of ctDNA in patients with solid tumors is gaining increasing attention, leading to a steady rise in the number of studies. However, many studies still suffer from small sample sizes and a lack of representativeness. Furthermore, details regarding ctDNA detection methods and results reporting are often insufficiently described. There is an urgent need to improve the quality of such research.

Circulating blood biomarkers for minimal residual disease in hepatocellular carcinoma: A systematic review

BACKGROUND

Relapse after radical treatment remains a major concern in hepatocellular carcinoma (HCC), affecting 50-75 % of early-stage cases within 5 years. Early recurrence prediction is a clinical unmet need. Circulating blood biomarkers could provide a minimally invasive approach to detect minimal residual disease (MRD) post-intervention. Although alpha-fetoprotein has been the primary biomarker in this setting, its MRD sensitivity is limited to 50-70 %. This systematic review aims to summarize available evidence regarding the clinical validity and potential utility of emerging circulating blood biomarkers for MRD detection in HCC patients.

METHODS

We searched PubMed and Embase for peer-reviewed articles and abstracts published up to 2025, and ClinicalTrials.gov for ongoing trials on circulating blood biomarkers for MRD in HCC.

RESULTS

A total of 91 studies (74 with results and 17 ongoing, out of 2,386) were retrieved. We evaluated various blood biomarkers, including circulating DNA (cDNA, N = 24), circulating tumor cells (CTCs, N = 20), circulating RNA (cRNA, N = 8), and other miscellaneous (N = 22) for MRD detection in HCC. These biomarkers demonstrated encouraging results, albeit with notable heterogeneity. In particular, circulating tumor DNA (ctDNA) and CTCs stand as the most robust novel approaches, with 50-80 % sensitivity and specificity up to 94 %. Nonetheless, none of the 17 ongoing studies involve biomarker-driven intervention to prove clinical utility.

CONCLUSIONS

Novel circulating blood biomarkers are mature for MRD detection in HCC. However, variability in methodologies and results highlights the need for further validation. We encourage the investigation of CTCs and/or ctDNA in interventional trials to assess clinical utility. This biomarker-driven approach may enhance adjuvant treatment effectiveness in MRD-positive cases while minimizing toxicity in MRD-negative patients.

Circulating tumor DNA as a biomarker of prognosis prediction in colorectal cancer: a systematic review and meta-analysis

Objective

Circulating tumor DNA (ctDNA) is increasingly being used as a potential biomarker in colorectal cancer (CRC) patients. However, the role of ctDNA in CRC prognosis prediction remains unclear. The objective is to systematically assess the clinical value of ctDNA in colorectal cancer prognosis prediction throughout the treatment cycle.

Methods

PubMed, Web of Science, Embase, Cochrane Library, Scopus, and clinical trials.gov database was searched from January 2016 to April 2023. Observational studies and randomized clinical trials reporting on ctDNA and prognostic outcomes in CRC patients were included. Pooled hazard risk ratios (HRs) were calculated for the primary outcomes, relapse-free survival (RFS), and overall survival (OS). Random-effects models were preferred considering the potential heterogeneity.

Results

Sixty-five cohort studies were included. Association between ctDNA and shorter RFS or OS was significant, especially after the full-course treatment recommended by the guidelines (HR = 8.92 [ 95 % CI: 6.02-13.22], P < 0.001, I2 = 73 %; HR = 3.05 [ 95 % CI: 1.72-5.41], P < 0.001, I2 = 48 %) for all types of CRC patients. Despite the presence of heterogeneity, subgroup analyses showed that the cancer type and ctDNA detection assays may be the underlying cause. Besides, ctDNA may detect recurrence earlier than radiographic progression, but no uniform sampling time point between studies might bring bias. However, ctDNA detection did not appear to correlate with pathological complete response achievement in patients with locally advanced rectal cancer.

Conclusion

ctDNA detection was significantly associated with poorer prognosis. The potential applications in prognostic prediction are promising and remain to be evaluated in other fields.

Single-Tube, Switched Temperature Amplicon Barcoding for Multiplex Detection of Rare Mutations in Circulating Tumor DNA

Detection and analysis of circulating tumor DNA (ctDNA) as a biomarker for cancer is a promising approach. Applications for ctDNA analysis include screening, diagnosis, treatment selection, treatment monitoring, minimal residual disease detection, and recurrence monitoring. Detection of ctDNA is challenging and requires highly sensitive methods. Approaches such as digital PCR are appropriate when only a small number of targets is being interrogated, whereas next-generation sequencing (NGS) is typically used when more targets are being analyzed. There are several NGS methods available, some of which are published and can be implemented in laboratories with the required expertise while other, commercial approaches are proprietary and are only available as a service. Of the published methods, most use some kind of unique molecular identifiers (or barcodes) to facilitate NGS error correction and detection of rare mutations at mutant allele frequencies of <0.1%. However, incorporation of barcodes and amplification of the resulting libraries are not trivial and typically require multiple steps and considerable hands-on time by an experienced molecular biologist. Herein, a novel approach for switched temperature amplicon barcoding was used, in which barcoding and library amplification were performed in the same tube using a two-stage PCR protocol with no additional manipulation. Total hands-on time was 10 to 15 minutes for reaction setup; the library was then cleaned and was ready for sequencing.

Circulating Tumor DNA in High-Risk Stage II/III Cutaneous Melanoma: A Feasibility Study

BACKGROUND

Adjuvant therapies reduce recurrence in patients with clinical stage IIB/IIC/III melanoma; however, better risk stratification and patient selection are needed. Circulating tumor DNA (ctDNA) as a marker of micrometastatic residual disease is being explored for such purposes in other malignancies. We aimed to explore the feasibility of serial ctDNA monitoring in patients with stage II/III melanoma, as well as the association of ctDNA elevation with disease burden and outcomes.

METHODS

A single-institution prospective study was conducted on patients with clinical stage IIB/IIC/III melanoma. Primary tumor was sent to Natera for generation of a tumor-informed mPCR-NGS assay (Signatera™). Peripheral blood was collected for analysis at pre-specified timepoints. Patients were stratified by ctDNA elevations both pre- and postoperatively to compare tumor characteristics and recurrence-free survival (RFS).

RESULTS

Overall, 30 patients were enrolled. The median Breslow depth was 4.4 mm and 70% were ulcerated. Signatera™ assays were successfully created for all 30 patients. Median follow-up from the time of surgery was 16 months and 13 patients recurred with median RFS of 19 months. Eight of these 13 patients (62%) had detectable ctDNA levels predating their clinical or radiographic recurrence. Elevated ctDNA at the first post-operative timepoint was associated with worse RFS.

CONCLUSIONS

ctDNA monitoring is feasible for patients with high-risk cutaneous melanoma. Our findings suggest that detectable ctDNA post-operatively may be associated with worse outcomes. Elevations during surveillance may predict subsequent clinical recurrence; however, the role of ctDNA in adjuvant therapy decision-making and surveillance is not yet ready for broad application.

Liquid biopsies in cancer

Cancer ranks among the most lethal diseases worldwide. Tissue biopsy is currently the primary method for the diagnosis and biological analysis of various solid tumors. However, this method has some disadvantages related to insufficient tissue specimen collection and intratumoral heterogeneity. Liquid biopsy is a noninvasive approach for identifying cancer-related biomarkers in peripheral blood, which allows for repetitive sampling across multiple time points. In the field of liquid biopsy, representative biomarkers include circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and exosomes. Many studies have evaluated the prognostic and predictive roles of CTCs and ctDNA in various solid tumors. Although these studies have limitations, the results of most studies appear to consistently demonstrate the correlations of high CTC counts and ctDNA mutations with lower survival rates in cancer patients. Similarly, a reduction in CTC counts throughout therapy may be a potential prognostic indicator related to treatment response in advanced cancer patients. Moreover, the biochemical characteristics of CTCs and ctDNA can provide information about tumor biology as well as resistance mechanisms against targeted therapy. This review discusses the current clinical applications of liquid biopsy in cancer patients, emphasizing its possible utility in outcome prediction and treatment decision-making.

Dynamic Tumor in Situ Fluid Circulating Tumor DNA Postsurgery Effectively Predicts Recurrence and Clinical Benefits for Glioblastomas

BACKGROUND AND OBJECTIVES

Glioblastoma (GBM) recurrence after surgery remains a significant clinical challenge because of limited early detection methods and effective molecular markers. This study investigates the potential of dynamic tumor in situ fluid circulating tumor DNA (TISF-ctDNA) as a tool for monitoring molecular residual disease and evaluating treatment efficacy in postsurgical patients with GBM.

METHODS

In this prospective cohort study, 75 resectable glioma patients were enrolled between October 2019 to June 2023. Primary tumor tissues and postsurgical TISF samples were collected, along with cranial imaging. TISF-ctDNA was identified through targeted next-generation sequencing, with positivity defined by the presence of one or more variants in the TISF matching those of the primary tumors or an increase of ≥10 single-nucleotide variants across consecutive assessments.

RESULTS

TISF-ctDNA positivity was identified in 62.2% of patients in the early postsurgical period, indicating a high prevalence of molecular residual disease. Patients with positive TISF-ctDNA showed a significantly higher risk of recurrence (hazard ratio 2.512, 95% CI 1.264-4.993, P = .0054). Conversion to TISF-ctDNA negativity post-treatment was associated with improved overall survival, highlighting its role in evaluating treatment response. Multivariate analysis revealed that TISF-ctDNA positivity was an independent predictor of progression-free survival during adjuvant therapy, with high predictive accuracy (sensitivity 86.2%, specificity 100%). Importantly, TISF-ctDNA positivity preceded imaging signs of recurrence by a median of 71 days. In this study, no significant impact of specific tumor markers in each subcohort (EGFR, TP53, PTEN, NF1) on progression-free survival or overall survival was observed.

CONCLUSION

TISF-ctDNA is a promising biomarker for monitoring GBM recurrence and evaluating clinical benefit. It provides insight into tumor genomic evolution and identifies patients who may benefit from adjuvant chemotherapy. TISF-ctDNA positivity is a robust prognostic indicator for patient outcomes and a marker for molecular recurrence after frontline therapy.

ctDNA as an Objective Marker for Postoperative Residual Disease in Primary Advanced High-Grade Serous Ovarian Cancer

BACKGROUND/OBJECTIVES

The surgeon's subjective intraoperative evaluation is the standard of care to assess postoperative residual disease (RD) in advanced epithelial ovarian cancer (EOC). We investigated the feasibility of ctDNA as an objective marker for postoperative RD.

METHODS

This prospective study included 27 patients with advanced ovarian cancer (FIGO IIIA1-IVB) who underwent primary surgery between July 2021 and July 2022. Blood samples were analyzed preoperatively and on days 2 (d2) and 10 (d10) postoperatively. Low-coverage whole genome sequencing (WGS) was used to identify structural variants (SVs) at single-base pair resolution, single nucleotide variants (SNVs), and indels in tumor tissue to develop personalized, tumor-informed digital polymerase chain reaction (dPCR) fingerprint assays for each patient.

RESULTS

dPCR fingerprint assays were successfully developed for all patients by identifying one to eight SVs/SNVs per patient. ctDNA was detected in 96% (n = 26/27) of patients preoperatively and in 81% (n = 22/27) of patients at d10. Median ctDNA levels at d10 were significantly higher in patients with postoperative RD (median 367.38 copies (cps)/mL, 2.84% variant allele frequency; VAF) than in patients without postoperative RD (median 0.92 cps/mL, 0.017% VAF, p < 0.001). In patients with postoperative RD, ctDNA levels increased from the preoperative stage to d10 in seven out of eight patients (p = 0.016). In patients with complete tumor resection, ctDNA levels decreased from the preoperative stage to d10 in 17/19 patients (p < 0.001).

CONCLUSIONS

A tumor-informed personalized ctDNA approach demonstrated feasibility, providing extremely high detection rates pre- and postoperatively. These results indicate that this approach could potentially be used for postoperative RD assessment in patients with primary advanced EOC.

A scoping review of factors influencing the implementation of liquid biopsy for cancer care

BACKGROUND

Liquid biopsy (LB) offers a promising, minimally invasive alternative to traditional tissue biopsies in cancer care, enabling real-time monitoring and personalized treatment. Despite its potential, the routine implementation of LB in clinical practice faces significant challenges. This scoping review examines the barriers and facilitators influencing the implementation of liquid biopsies into standard cancer care.

METHODS

Four academic databases (PubMed, Scopus, Embase, and Web of Science) were systematically searched without language restrictions. We included peer-reviewed articles that were published between January 2019 and March 2024 that focused on the implementation of LB in cancer care or described barriers and facilitators to its implementation. Data relevant to the review objective, including key article characteristics; barriers and facilitators of implementation; and recommendations for advancement or optimisation; were extracted and analysed using thematic and visual network analyses.

RESULTS

The majority of the included articles were narrative review articles (84%), with most from China (24.2%) and the United States (20%). Thematic analysis identified four main categories and their associated barriers and facilitators to the implementation of LB in cancer care: (1) Laboratory and personnel requirements; (2) Disease specificity; (3) Biomarker-based liquid biopsy; and (4) Policy and regulation. The majority of barriers identified were concentrated in the pre-analytical phase, highlighting the lack of standardization in LB technologies and outcomes.

CONCLUSIONS

Through a thematic analysis of the barriers and facilitators to LB implementation, we present an integrated tool designed to encourage the standardization of testing methods for clinical practice guidelines in the field.

Unveiling intricating roles and mechanisms of ferroptosis in melanoma

Melanoma is a highly invasive malignant tumor originating from melanocytes, with increasing incidence in recent years. Ferroptosis is an iron-dependent and non-apoptotic form of programmed cell death characterized by the accumulation of lipid peroxides and reactive oxygen species. Morphologically, ferroptosis exhibits the alteration in cells, such as reduced mitochondrial volume, increased density of bilayer membrane, and a decrease or disappearance of mitochondrial cristae. Ferroptosis has shown tremendous potential and applicability in regulating the development of melanoma. As melanoma progresses, certain biomarkers associated with ferroptosis display characteristic patterns of expression. These changes not only reveal the sensitivity of tumor cells to ferroptosis but also provide potential targets for diagnosis and treatment. Besides, inducing ferroptosis has been well-documented to inhibit the growth of melanoma and enhance the efficacy of tumor immunotherapy. Hence, this review emphasizes the roles and regulatory mechanisms of ferroptosis in melanoma development, the involved immune regulation, as well as the potential for diagnosis and treatment of melanoma. The continuous explorations will endow novel strategies for developing ferroptosis-based therapies for melanoma.

Multi-cancer early detection tests: Attributes for clinical implementation

Guideline-recommended screening programs exist for only a few single-cancer types, and these cancers represent less than one-half of all new cancer cases diagnosed each year in the U.S. In addition, these "single-cancer" standard of care (SoC) screening tests vary in accuracy, adherence, and effectiveness, though all are generally understood to lead to reductions in cancer-related mortality. Recent advances in high-throughput technologies and machine learning have facilitated the development of blood-based multi-cancer early detection (MCED) tests. The opportunity for early detection of multiple cancers with a single blood test holds promise in addressing the current unmet need in cancer screening. By complementing existing SoC screening, MCED tests have the potential to detect a wide range of cancers at earlier stages when patients are asymptomatic, enabling more effective treatment options and improved cancer outcomes. MCED tests are positioned to be utilized as a complementary screening tool to improve screening adherence at the population level, to broaden screening availability for individuals who are not adherent with SoC screening programs, as well as for those who may harbor cancers that do not have SoC testing available. Published work to date has primarily focused on test performance relating to sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). MCED tests will require approval through the pre-market approval pathway from the United States Food and Drug Administration. Additional studies will be needed to demonstrate clinical utility (i.e., improvements in health outcomes) and establish optimal implementation strategies, (i.e., testing intervals), follow-up and logistics of shared decision making. Here, we propose core attributes of MCED testing for which clinical data are needed to ideally position MCED testing for widespread use in clinical practice.

The Evolving Role of Genomics in Colorectal Cancer

Approximately 75% of colorectal cancers (CRCs) harbour an identifiable driver mutation, 5% of which are heritable. These drivers have recognised implications for prognosis and therapy selection. In addition, potential germline mutations require investigations to inform testing of relatives, as well as surveillance for other malignancies. With increasing numbers of targeted drugs being approved, judicious testing is required to ensure sufficient tumour sample is available for testing and at the right point in the cancer pathway. Liquid biopsy with circulating tumour DNA (ctDNA) in the blood presents an exciting adjunct to tumour tissue testing for molecular drivers, as well as escalation and de-escalation of therapy. Here, we review the most frequent molecular alterations in CRC, how genomic testing should be integrated into the treatment pathway for CRC, and sources of further education.

Elements of liquid biopsies: isolation, analysis, and clinical application in cancer diagnosis to prognosis

INTRODUCTION

The liquid biopsy is a breakthrough in the field of medical diagnostics. It serves as a sentinel that can quietly detect even the subtlest aberrations that indicate the presence of disease. They make it possible to uncover relevant genetic factors of tumors with minimal to no risk to cancer patients. Liquid biopsies allow detailed diagnosis, dynamic treatment monitoring, and accurate prognosis. They are also invaluable in diagnosing other diseases such as infectious diseases and aberrant gene mutations.

AREAS COVERED

The present review undertakes an in-depth analysis of the existing status of liquid biopsy diagnostic tools, focusing on their principal components. Furthermore, the review highlights pertinent and recent research in this field to provide a comprehensive understanding of the current state of this technology and its prospects.

EXPERT OPINION

Despite new and upcoming research in liquid biopsies, multiple areas need to be further explored before the viable transition into the clinical arena. With the advancements in tools such as artificial intelligence and machine learning and the integration of these technologies with liquid biopsies, these challenges are being addressed and will eventually lead to the development of a highly evolved liquid biopsy diagnostic tools.

Non-Invasive Tumor-Naïve Minimal Residual Disease Detection of Liver Cancer by Incorporating Circulating Tumor DNA Features and Alpha-Fetoprotein: A Prospective Study

BACKGROUND AND PURPOSE

Liver cancer has a high recurrence rate of 50%~70% for early-stage patients. Minimal residual disease (MRD) is strongly linked to liver cancer early recurrence. Identifying MRD through reliable prognostic biomarkers, such as circulating tumor DNA (ctDNA), could significantly benefit these patients by enabling timely intervention and improved outcomes.

MATERIALS AND METHODS

A prospective study enrolled 32 liver cancer patients undergoing radical surgery. Peripheral blood samples (8 mL) were collected before and after surgery. In this study, we expanded upon our previously developed multi-omics assay, initially designed for liver cancer early detection by calculating a cancer signal score (PHCC), to determine the MRD status (named SeekInCure). This process integrated protein tumor marker alpha-fetoprotein (AFP) and cancer genomic hallmarks, copy number aberration (CNA) and fragment size (FS).

RESULTS

Of the enrolled patients, 78.1% were in early stages, and before surgery, 87.5% of patients had successfully detected the cancer signal in blood. After radical surgery, 23 patients were MRD-negative, exhibiting better overall survival compared to the MRD-positive patients (n = 9, p < 0.01). Patients maintaining undetectable cancer signals pre- and post-surgery showed 100% survival, conversely, those keeping with detectable signals had a 55.6% mortality rate.

CONCLUSION

This prospective study highlights the prognostic value of ctDNA-based tumor-naïve MRD detection through a multi-omics assay in early-stage liver cancer patients.

Circulating tumor DNA fraction predicts residual cancer burden post-neoadjuvant chemotherapy in triple negative breast cancer

Purpose

Pathologic response after preoperative/neoadjuvant chemotherapy (NAC) is a continuum that can range from complete pathologic response (pCR) to extensive residual disease (RD). We hypothesized that post-NAC plasma circulating tumor DNA (ctDNA) fraction (TF) reflect pathologic response as continuum measured by the residual cancer burden (RCB) score.

Methods

ctDNA was assessed using the PredicineBEACON assay, that interrogates up to 50 personalized tumor variants and 500 hot-spot mutations, in 3 mL archived plasma isolated from EDTA tubes collected post-NAC but before surgery from 44 patients with stage I/III triple negative breast cancer (TNBC) who received durvalumab and weekly nab-paclitaxel followed by doxorubicin/cyclophosphamide on a clinical trial (NCT02489448). Circulating free tumor DNA methylation profiling was performed using PredicineEPIC assay in paired pre- and post-NAC plasma (N = 30). Youden's J-statistics was used to define optimal thresholds.

Results

We observed a significant positive correlation (r = 0.45, p = 0.004) between RCB scores and post-NAC TF. The median TF was significantly lower in pCR (RCB0) compared to RD patients (0.06 % vs. 0.3 %, p = 0.02). Using a TF positivity threshold of ≥0.05 %, PredicineBEACON had 58 % sensitivity at 83 % specificity for identifying RD. TF was higher in patients who experienced recurrence (n = 9) compared to those without recurrence (n = 35) (0.17 % vs. 0.05 % TF, p = 0.029). There was significant decrease in methylation signal in post-compared to pre-NAC samples, but post-treatment methylation signal was lower in cases with pCR vs RD.

Conclusions

Post-NAC plasma tumor fraction and change in tumor-derived methylation signal predict the extent of RD and recurrence in TNBC patients.

Efficacy of neoadjuvant therapy and lymph node dissection in advanced gallbladder cancer without distant metastases: a SEER database analysis

Purpose

To investigate the effectiveness of neoadjuvant therapy and lymph node dissection(LND) on overall survival (OS) in patients with stage III/IV gallbladder cancer without distant metastases.

Methods

Data from 101 patients who received neoadjuvant therapy followed by surgery combined with adjuvant chemotherapy, and 1412 patients who received direct surgical treatment followed by adjuvant chemotherapy, were collected from the SEER database from 2004 to 2020. Patients were divided into group A (neoadjuvant therapy) and group B (direct surgery) based on the treatment modality. A total of 202 cases were obtained after propensity score matching, with 101 cases in each group (A and B). Cox unifactorial and multifactorial analyses were performed to identify independent risk factors for patients with advanced cholecystic carcinoma, and the Kaplan-Meier method was used to analyze overall survival (OS). The Cox proportional hazards model was used to investigate the effect of different subgroups on OS in both patient groups. Further survival analyses were conducted to determine whether lymph node dissection(LND) was beneficial for patients receiving neoadjuvant therapy for gallbladder cancer.

Results

Cox univariate analysis showed that marital status, AJCC stage, number of LND, tumor size, and treatment modality were associated with OS (P<0.05). Cox multifactorial regression analysis indicated that AJCC stage, LND, tumor size, and treatment modality were independent risk factors for OS in patients with non-metastatic advanced gallbladder cancer (P<0.05). Survival curves demonstrated that the OS in group A was longer than in group B (median OS: 30 months vs. 14 months, P<0.001). Subgroup analysis indicated that neoadjuvant therapy had a consistent effect on the OS of patients with advanced gallbladder cancer, improving both survival time and outcomes. Survival curves indicated that lymph node dissection was not significant in group A patients (p>0.05) but was significant in group B (p<0.05).

Conclusion

Neoadjuvant therapy can improve the OS of patients with non-metastatic stage III/IV gallbladder cancer and is an independent risk factor affecting prognosis; however, the significance of lymph node dissection in these patients still needs further study.

Clinical Utility of Tumor-Naïve Presurgical Circulating Tumor DNA Detection in Early-Stage NSCLC

OBJECTIVES

The use of tumor-informed circulating tumor DNA (ctDNA) testing in patients with early-stage disease before surgery is limited, mainly owing to restricted tissue access and extended turnaround times. This study aimed to evaluate the clinical value of a tumor-naïve, methylation-based cell-free DNA assay in a large cohort of patients with resected NSCLC.

METHOD

We analyzed presurgical plasma samples from 895 patients with EGFR and anaplastic lymphoma kinase-wild-type, clinical stage I or II NSCLC. The ctDNA status was evaluated for its prognostic significance in relation to tumor volume, metabolic activity, histologic diagnosis, histologic subtypes, and clinical-to-pathologic TNM upstaging.

RESULTS

Presurgical ctDNA detection was observed in 55 of 414 patients (13%) with clinical stage I lung adenocarcinoma (LUAD) and was associated with poor recurrence-free survival (2-year recurrence-free survival 69% versus 91%; log-rank p < 0.001), approaching that of clinical stage II LUAD. Presurgical ctDNA detection was not prognostic in patients with clinical stage II LUAD or non-LUAD. Within LUAD, tumor volume and positron emission tomography avidity interacted to predict presurgical ctDNA detection. Moreover, presurgical ctDNA detection was predictive of the postsurgical discovery of International Association for the Study of Lung Cancer grade 3 tumors (p < 0.001) and pathologic TNM upstaging (p < 0.001). Notably, presurgical ctDNA detection strongly correlated with higher programmed death-ligand 1 expression in tumors (positive rates 28% versus 55%, p < 0.001), identifying a subgroup likely to benefit from anti-programmed death-ligand 1 therapies.

CONCLUSION

These findings support the integration of ctDNA testing into routine diagnostic workflows in early-stage NSCLC without the need for tumor tissue profiling. Furthermore, it is clinically useful in identifying patients at high risk who might benefit from innovative treatments, including neoadjuvant immune checkpoint inhibitors.

CRISPR-Cas-based biosensors for the detection of cancer biomarkers

Along with discovering cancer biomarkers, non-invasive detection methods have played a critical role in early cancer diagnosis and prognostic improvement. Some traditional detection methods have been used for detecting cancer biomarkers, but they are time-consuming and involve materials and human costs. With great flexibility, sensitivity and specificity, the clustered regularly interspaced short palindromic repeats (CRISPR)-associated system provides a wide range of application prospects in this field. Herein, we introduce the background of the CRISPR-Cas (CRISPR-associated) system and comprehensively summarize the diagnosis strategies of cancer mediated by the CRISPR-Cas system, including four kinds of biochemical-based markers: nucleic acid, enzyme, tumor-specific protein and exosome. Furthermore, we discuss the challenges in implementing the CRISPR-Cas system in clinical applications.

Liquid biopsy for early cancer detection: technological revolutions and clinical dilemma

INTRODUCTION

Liquid biopsy is an innovative advancement in oncology, offering a noninvasive method for early cancer detection and monitoring by analyzing circulating tumor cells, DNA, RNA, and other biomarkers in bodily fluids. This technique has the potential to revolutionize precision oncology by providing real-time analysis of tumor dynamics, enabling early detection, monitoring treatment responses, and tailoring personalized therapies based on the molecular profiles of individual patients.

AREAS COVERED

In this review, the authors discuss current methodologies, technological challenges, and clinical applications of liquid biopsy. This includes advancements in detecting minimal residual disease, tracking tumor evolution, and combining liquid biopsy with other diagnostic modalities for precision oncology. Key areas explored are the sensitivity, specificity, and integration of multi-omics, AI, ML, and LLM technologies.

EXPERT OPINION

Liquid biopsy holds great potential to revolutionize cancer care through early detection and personalized treatment strategies. However, its success depends on overcoming technological and clinical hurdles, such as ensuring high sensitivity and specificity, interpreting results amidst tumor heterogeneity, and making tests accessible and affordable. Continued innovation and collaboration are crucial to fully realize the potential of liquid biopsy in improving early cancer detection, treatment, and monitoring.

Longitudinal Tumor-informed Circulating Tumor DNA Status Predicts Disease Upstaging and Poor Prognosis for Patients Undergoing Radical Cystectomy

BACKGROUND AND OBJECTIVE

Decision-making on the use of neoadjuvant and adjuvant treatment for patients with bladder cancer undergoing radical cystectomy (RC) currently depends on assessment of clinical and pathological features, which lack sensitivity. Circulating tumor DNA (ctDNA) has emerged as a possible novel prognostic biomarker in the field. Our aim was to assess whether ctDNA status before RC is predictive of pathological and oncological outcomes. We also evaluated the dynamic changes in ctDNA status after RC in relation to recurrence-free survival (RFS).

METHODS

We analyzed data for patients who underwent RC during 2021-2023 for whom prospective tumor-informed ctDNA analyses were conducted before and after RC. RFS was evaluated using the Kaplan-Meier method. Predictors for disease recurrence were assessed using Cox proportional-hazards models. Pathological outcomes associated with detectable ctDNA before RC were assessed in univariable and multivariable regression analyses.

KEY FINDINGS AND LIMITATIONS

We included 112 patients in the analysis. Median follow-up was 8 mo (interquartile range 4-13). ctDNA was detected before RC in 59 patients (53%) and was associated with poor RFS (log-rank p < 0.0001). Detectable ctDNA before RC was associated with poor outcomes regardless of clinical stage (

CONCLUSIONS AND CLINICAL IMPLICATIONS

Detectable ctDNA before definitive therapy with RC is predictive of nodal involvement, locally advanced disease, and disease recurrence in patients with bladder cancer. ctDNA status holds promise for improving clinical staging and augmenting current decision-making tools.

PATIENT SUMMARY

We found that for patients with bladder cancer undergoing radical cystectomy, a test to show the presence of tumor DNA in blood before surgery was able to predict the risk of disease relapse and adverse pathology. Use of this assay could help in decision-making by clinicians and patients for optimal personalized treatment of this disease.

Collapse

Key Words

• Circulating tumor DNA
• Non–muscle-invasive bladder neoplasms
• Tumor biomarkers
• Urinary bladder neoplasms

Collapse

MESH Headings

• Humans
• Cystectomy/methods
• Urinary Bladder Neoplasms/surgery
• Urinary Bladder Neoplasms/blood
• Urinary Bladder Neoplasms/pathology
• Urinary Bladder Neoplasms/genetics
• Male
• Female
• Circulating Tumor DNA/blood
• Aged
• Prognosis
• Neoplasm Staging
• Middle Aged
• Prospective Studies

Collapse

Grants Collapse

Affiliation(s)

Reuben Ben-David Urology Department, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Neeraja Tillu Urology Department, Icahn School of Medicine at Mount Sinai, New York, NY, USA
Shivaram Cumarasamy Urology Department, Icahn School of Medicine at Mount Sinai, New York, NY, USA
Parissa Alerasool The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
Jordan M Rich Urology Department, Icahn School of Medicine at Mount Sinai, New York, NY, USA
Basil Kaufmann Urology Department, Icahn School of Medicine at Mount Sinai, New York, NY, USA
Yuval Elkun Urology Department, Icahn School of Medicine at Mount Sinai, New York, NY, USA
Kyrollis Attalla Urology Department, Icahn School of Medicine at Mount Sinai, New York, NY, USA
Reza Mehrazin Urology Department, Icahn School of Medicine at Mount Sinai, New York, NY, USA
Peter Wiklund Urology Department, Icahn School of Medicine at Mount Sinai, New York, NY, USA
John P Sfakianos Urology Department, Icahn School of Medicine at Mount Sinai, New York, NY, USA

Collapse

Poor compliance with germline testing recommendations in colorectal cancer patients undergoing molecular residual disease testing

BACKGROUND

Approximately 15% of colorectal cancers (CRCs) are associated with germline mutations. There is increasing adoption of DNA-based assays for molecular residual disease (MRD) and growing evidence supporting its clinical utility, particularly for CRC by oncologists in the U.S. We assessed the uptake of germline multi-gene panel testing (MGPT) for hereditary cancer in CRC patients receiving MRD analyses in community oncology settings.

METHODS

This retrospective study included 80 patients receiving care for CRC through community oncology practices who were referred for MRD testing at a commercial laboratory (January-March 2022). Clinical data, including test requisition forms, pathology reports, and clinical notes were reviewed. Documentation of tumor microsatellite instability and/or immunohistochemical (IHC) testing for mismatch repair (MMR) deficiency, age of CRC diagnosis, family history of cancer, and any order or recommendation for MGPT were assessed.

RESULTS

Overall, 5/80 (6.3%) patients in the study have documented germline MGPT; 65/80 (81.3%) patients have documented MMR testing of their colorectal tumor. Among the 5 cases with abnormal MMR IHC, 2 have MGPT. Of the 33 patients meeting the 2021 National Comprehensive Cancer Network (NCCN) criteria for genetic/familial high-risk assessment, only 2 have MGPT.

CONCLUSIONS

Our real-world data suggest that many CRC patients receiving MRD testing and meeting NCCN (v. 2021) criteria for germline MGPT may not be receiving evaluation beyond routine MMR status. Process and educational improvements are needed in community health settings to increase access and uptake of germline testing among CRC patients regardless of age at diagnosis or MMR status.

Mutational spectrum of breast cancer by shallow whole-genome sequencing of cfDNA and tumor gene panel analysis

Breast cancer (BC) has different molecular subgroups related to different risks and treatments. Tumor biopsies for BC detection are invasive and may not reflect tumor heterogeneity. Liquid biopsies have become relevant because they might overcome these limitations. We rationalize that liquid cfDNA biopsies through shallow whole genome sequencing (sWGS) could improve the detection of tumor alterations, complementing the genomic profiling. We evaluated the feasibility to detect somatic copy number alterations (SCNAs) in BC using shallow whole genome sequencing (sWGS) in cfDNA from archived samples from National Cancer Institute of Colombia patients. We sequenced tumor tissues from 38 BC patients with different molecular subtypes using a gene panel of 176 genes significantly mutated in cancer, and by liquid biopsies using sWGS on 20 paired samples to detect SCNAs and compare with the tumor samples. We identified an extensive intertumoral heterogeneity between the molecular subtypes of BC, with a mean tumor load of 602 mutations in the gene panel of tumor tissues. There was a 12.3% of concordance in deletions in the cfDNA-tumor pairs considering only the genes covered by the panel encompassing seven genes: BRCA1, CDK12, NF1, MAP2K4, NCOR1, TP53, and KEAP1 in three patients. This study shows the feasibility to complement the genomic analysis of tumor tissue biopsies to detect SCNA in BC using sWGS in cfDNA, providing a wider identification of potential therapeutic targets.

Identification of circulating tumor DNA as a biomarker for diagnosis and response to therapies in cancer patients

The sampling of circulating biomarkers provides an opportunity for non-invasive evaluation and monitoring of cancer activity. In modern day practice, this has typically been in the form of circulating tumor DNA (ctDNA) detected in plasma. The field of ctDNA has been a burgeoning technology, with prominent applications for blood-based cancer screening and in disease status assessment, especially after curative-intent surgery to evaluate for minimal residual disease (MRD). Clinical applications for the latter show an incredibly high sensitivity in certain cancer types with a need for additional studies to determine how much clinical decision-making should be adapted based on ctDNA results and which cancer types, stages, and treatments are best informed by ctDNA results. This chapter provides an overview of ctDNA detection as tool for cancer screening, detecting MRD, and/or molecularly characterizing a cancer, highlighting the rapidly amassing research as a prognostic biomarker and emerging data on ctDNA as a predictive biomarker.

Tumor Characteristics Associated With Preoperatively Detectable Tumor-Informed Circulating Tumor DNA in Patients With Renal Masses Suspicious for Renal Cell Carcinoma

PURPOSE

Understanding the specific tumor characteristics associated with detectable circulating tumor DNA (ctDNA) in patients with renal cell carcinoma (RCC) is critical for informing future studies aiming to establish the clinical utility of such testing. We characterized the pathologic and clinical features associated with preoperatively detectable ctDNA in patients with renal masses suspicious for RCC.

METHODS

Consecutive patients who underwent partial or radical nephrectomy for nonmetastatic suspected RCC (cT1b-T3) during 2022-2023 had prospectively collected tumor-informed ctDNA analyses conducted preoperatively and postoperatively. Descriptive statistics and univariate analyses were used to describe the study findings.

RESULTS

Sixty-nine patients with a median age of 62 years (IQR, 51-70) and a median follow-up time of 7 months (IQR, 3-11) had 205 ctDNA samples collected for analysis. Thirty-nine (61%) had preoperative detectable ctDNA of 64 patients. Postoperative ctDNA status was available for 47 patients, and three (6%) had detectable ctDNA. Two had inferior vena cava (IVC) involvement, and one developed metastatic disease. Subgroup analysis of solely malignant RCC (n = 65) revealed that patients with preoperative detectable ctDNA had a higher pathologic stage (P = .001), larger tumors (7 v 4.5 cm; P = .001), higher tumor complexity (P = .022), and increased rates of tumor grades 3-4 (P = .038). All patients with gross renal vein or IVC involvement (n = 9) and those with lymphovascular invasion (n = 6) on pathology had detectable preoperative ctDNA. On univariate analysis, high tumor complexity, larger tumors, and tumor grades 3-4 were found to be predictors of preoperatively detectable ctDNA status.

CONCLUSION

Preoperative ctDNA was detectable in 61% of patients with nonmetastatic RCC, and it correlated with clinically relevant features. Clinical trials should consider incorporating both preoperative and postoperative ctDNA analyses to augment prediction of disease recurrence and to refine treatment decision making.

Advancements in melanoma immunotherapy: the emergence of Extracellular Vesicle Vaccines

Malignant melanoma represents a particularly aggressive type of skin cancer, originating from the pathological transformation of melanocytes. While conventional interventions such as surgical resection, chemotherapy, and radiation therapy are available, their non-specificity and collateral damage to normal cells has shifted the focus towards immunotherapy as a notable approach. Extracellular vesicles (EVs) are naturally occurring transporters, and are capable of delivering tumor-specific antigens and directly engaging in the immune response. Multiple types of EVs have emerged as promising platforms for melanoma vaccination. The effectiveness of EV-based melanoma vaccines manifests their ability to potentiate the immune response, particularly by activating dendritic cells (DCs) and CD8+ T lymphocytes, through engineering a synergy of antigen presentation and targeted delivery. Here, this review mainly focuses on the construction strategies for EV vaccines from various sources, their effects, and immunological mechanisms in treating melanoma, as well as the shortcomings and future perspectives in this field. These findings will provide novel insights into the innovative exploitation of EV-based vaccines for melanoma immune therapy.

Nicotinamide Riboside-Driven Modulation of SIRT3/mtROS/JNK Signaling Pathways Alleviates Myocardial Ischemia-Reperfusion Injury

Myocardial ischemia-reperfusion (I/R) injury exacerbates cellular damage upon restoring blood flow to ischemic cardiac tissue, causing oxidative stress, inflammation, and apoptosis. This study investigates Nicotinamide Riboside (NR), a precursor of nicotinamide adenine dinucleotide (NAD+), for its cardioprotective effects. Administering NR to mice before I/R injury and evaluating heart function via echocardiography showed that NR significantly improved heart function, increased left ventricular ejection fraction (LVEF) and fractional shortening (FS), and reduced left ventricular end-diastolic (LVDd) and end-systolic diameters (LVSd). NR also restored E/A and E/e' ratios. It reduced cardiomyocyte apoptosis both in vivo and in vitro, inhibiting elevated caspase-3 activity and returning Bax protein levels to normal. In vitro, NR reduced the apoptotic rate in hydrogen peroxide (H2O2)-treated HL-1 cells from 30% to 10%. Mechanistically, NR modulated the SIRT3/mtROS/JNK pathway, reversing H2O2-induced SIRT3 downregulation, reducing mitochondrial reactive oxygen species (mtROS), and inhibiting JNK activation. Using SIRT3-knockout (SIRT3-KO) mice, we confirmed that NR's cardioprotective effects depend on SIRT3. Echocardiography showed that NR's benefits were abrogated in SIRT3-KO mice. In conclusion, NR provides significant cardioprotection against myocardial I/R injury by enhancing NAD+ levels and modulating the SIRT3/mtROS/JNK pathway, suggesting its potential as a novel therapeutic agent for ischemic heart diseases, meriting further clinical research.

MS4A1-PTGS2 axis induces taurine metabolic reprogramming to exacerbate abdominal aortic aneurysm progression

This study unveils the pivotal roles of taurine metabolic reprogramming and its implications in the development and progression of Abdominal Aortic Aneurysm (AAA). Leveraging an integrated approach that combines single-cell RNA sequencing (scRNA-seq) and Weighted Gene Co-expression Network Analysis (WGCNA), our research investigates the intricate transcriptional and gene expression dynamics crucial to AAA. Our findings uniquely link metabolic shifts to the integrity of the extracellular matrix (ECM) and the functionality of smooth muscle cells (SMCs), key elements in the pathology of AAA. Utilizing scRNA-seq data from a mouse model (GSE152583 dataset), we identified critical alterations in cellular composition during AAA progression, particularly highlighting shifts in fibroblasts and inflammatory cells. Concurrently, WGCNA of human AAA tissue samples has outlined distinct gene expression patterns correlated with disease severity and progression, offering comprehensive insights into both molecular and cellular disease mechanisms. Moreover, this study introduces innovative metabolic profiling techniques to identify differential metabolites in AAA, integrating extensive metabolomic analyses with pathway enrichment strategies. This novel approach has pinpointed potential biomarkers and therapeutic targets, notably within taurine metabolism pathways, crucial for crafting non-surgical interventions. By merging state-of-the-art bioinformatics with thorough molecular analysis, our study not only enhances the understanding of AAA's complex pathophysiology but also catalyzes the development of targeted therapeutic strategies. This research represents a significant advancement in the molecular characterization of AAA, with substantial implications for its future diagnosis and treatment strategies.

Current updates on the molecular and genetic signals as diagnostic and therapeutic targets for hepatitis B virus-associated hepatic malignancy

Liver cancer caused by the hepatitis B virus (HBV) is the third most common cancer-related cause of death worldwide. Early detection of HBV-caused hepatic tumors increases the likelihood of a successful cure. Molecular and genetic signals are becoming more and more recognized as possible indicators of HBV-associated hepatic malignancy and of how well a treatment is working. As a result, we have discussed the current literature on molecular and genetic sensors, including extracellular vesicle microRNAs (EV-miRNAs), long non-coding circulating RNAs (lncRNAs), extracellular vesicles (EVs), and cell free circulating DNA (cfDNA), for the diagnosis and forecasting of HBV-related hepatic cancer. Extracellular vesicle microRNAs such as miR-335-5p, miR-172-5p, miR-1285-5p, miR-497-5p, miR-636, miR-187-5p, miR-223-3p, miR-21, miR-324-3p, miR-210-3p, miR-718, miR-122, miR-522, miR-0308-3p, and miR-375 are essential for the posttranscriptional regulation of oncogenes in hepatic cells as well as the epigenetic modulation of many internal and external signaling pathways in HBV-induced hepatic carcinogenesis. LncRNAs like lnc01977, HULC (highly up-regulated in liver cancer), MALAT1 (metastasis-associated lung adenocarcinoma transcript 1), and HOTAIR (hox transcript antisense intergenic RNA) have been demonstrated to control hepatic-tumors cell growth, relocation, encroachment, and cell death resiliency. They are also becoming more and more involved in immune tracking, hepatic shifting, vasculature oversight, and genomic destabilization. EVs are critical mediators involved in multiple aspects of liver-tumors like angiogenesis, immunology, tumor formation, and the dissemination of malignant hepatocytes. Furthermore, cfDNA contributes to signals associated with tumors, including mutations and abnormal epigenetic changes during HBV-related hepatic tumorigenesis.

UK Stakeholder Perspectives on Surrogate Endpoints in Cancer, and the Potential for UK Real-World Datasets to Validate Their Use in Decision-Making

Duration of overall survival in patients with cancer has lengthened due to earlier detection and improved treatments. However, these improvements have created challenges in assessing the impact of newer treatments, particularly those used early in the treatment pathway. As overall survival remains most decision-makers' preferred primary endpoint, therapeutic innovations may take a long time to be introduced into clinical practice. Moreover, it is difficult to extrapolate findings to heterogeneous populations and address the concerns of patients wishing to evaluate everyday quality and extension of life. There is growing interest in the use of surrogate or interim endpoints to demonstrate robust treatment effects sooner than is possible with measurement of overall survival. It is hoped that they could speed up patients' access to new drugs, combinations, and sequences, and inform treatment decision-making. However, while surrogate endpoints have been used by regulators for drug approvals, this has occurred on a case-by-case basis. Evidence standards are yet to be clearly defined for acceptability in health technology appraisals or to shape clinical practice. This article considers the relevance of the use of surrogate endpoints in cancer in the UK context, and explores whether collection and analysis of real-world UK data and evidence might contribute to validation.

Exploring the Role of Clustered Mutations in Carcinogenesis and Their Potential Clinical Implications in Cancer

Abnormal cell proliferation and growth leading to cancer primarily result from cumulative genome mutations. Single gene mutations alone do not fully explain cancer onset and progression; instead, clustered mutations-simultaneous occurrences of multiple mutations-are considered to be pivotal in cancer development and advancement. These mutations can affect different genes and pathways, resulting in cells undergoing malignant transformation with multiple functional abnormalities. Clustered mutations influence cancer growth rates, metastatic potential, and drug treatment sensitivity. This summary highlights the various types and characteristics of clustered mutations to understand their associations with carcinogenesis and discusses their potential clinical significance in cancer. As a unique mutation type, clustered mutations may involve genomic instability, DNA repair mechanism defects, and environmental exposures, potentially correlating with responsiveness to immunotherapy. Understanding the characteristics and underlying processes of clustered mutations enhances our comprehension of carcinogenesis and cancer progression, providing new diagnostic and therapeutic approaches for cancer.

An Aging-Related lncRNA Signature Establishing for Breast Cancer Prognosis and Immunotherapy Responsiveness Prediction

Purpose

Emerging evidence demonstrates the vital role of aging and long non-coding RNAs (lncRNAs) in breast cancer (BC) progression. Our study intended to develop a prognostic risk model based on aging-related lncRNAs (AG-lncs) to foresee BC patients' outcomes.

Patients and Methods

307 aging-related genes (AGs) were sequenced from the TCGA project. Then, 697 AG-lncs were identified by the co-expression analysis with AGs. Using multivariate and univariate Cox regression analysis, and LASSO, 6 AG-lncs, including al136531.1, mapt-as1, al451085.2, otud6b-as1, tnfrsf14-as1, and linc01871, were validated to compute the risk score and establish a risk signature. Expression levels of al136531.1, mapt-as1, al451085.2, tnfrsf14-as1, and linc01871 were higher in low-risk BC patients, whereas otud6b-as1 expression was higher in high-risk BC patients. In the training and testing set, high-risk patients performed shorter PFI, OS, and DFS than low-risk patients.

Results

Our risk signature had the highest concordance index among other established prognostic signatures and displayed ideal predictive ability for 1-, 3- and 5-year patient OS in the nomogram. Additionally, BC patients with different risk score levels showed different immune statuses and responses to immunotherapy via GSEA, ssGSEA, ESTIMATE algorithm, and TIDE algorithm analysis. Of note, the qRT-PCR analysis validated that these 6 AG-lncs expressed quite differentially in BC tissues at various clinical stages.

Conclusion

The risk signature of 6 AG-lncs might offer a novel prognostic biomarker and promisingly enhance BC immunotherapy's effectiveness.

Current landscape of exosomes in tuberculosis development, diagnosis, and treatment applications

Tuberculosis (TB), caused by the bacterial pathogen Mycobacterium tuberculosis (MTB), remains one of the most prevalent and deadly infectious diseases worldwide. Currently, there are complex interactions between host cells and pathogens in TB. The onset, progression, and regression of TB are correlated not only with the virulence of MTB but also with the immunity of TB patients. Exosomes are cell-secreted membrane-bound nanovesicles with lipid bilayers that contain a variety of biomolecules, such as metabolites, lipids, proteins, and nucleic acids. Exosome-mediated cell-cell communication and interactions with the microenvironment represent crucial mechanisms through which exosomes exert their functional effects. Exosomes harbor a wide range of regulatory roles in physiological and pathological conditions, including MTB infection. Exosomes can regulate the immune response, metabolism, and cellular death to remodel the progression of MTB infection. During MTB infection, exosomes display distinctive profiles and quantities that may act as diagnostic biomarkers, suggesting that exosomes provide a revealing glimpse into the evolving landscape of MTB infections. Furthermore, exosomes derived from MTB and mesenchymal stem cells can be harnessed as vaccine platforms and drug delivery vehicles for the precise targeting and treatment of TB. In this review, we highlight the functions and mechanisms through which exosomes influence the progression of TB. Additionally, we unravel the critical significance of exosomal constituents in the diagnosis and therapeutic applications of TB, aiming to offer novel perspectives and strategies for combating TB.

Integrating Imaging and Circulating Tumor DNA Features for Predicting Patient Outcomes

Biomarkers for evaluating tumor response to therapy and estimating the risk of disease relapse represent tremendous areas of clinical need. To evaluate treatment efficacy, tumor response is routinely assessed using different imaging modalities like positron emission tomography/computed tomography or magnetic resonance imaging. More recently, the development of circulating tumor DNA detection assays has provided a minimally invasive approach to evaluate tumor response and prognosis through a blood test (liquid biopsy). Integrating imaging- and circulating tumor DNA-based biomarkers may lead to improvements in the prediction of patient outcomes. For this mini-review, we searched the scientific literature to find original articles that combined quantitative imaging and circulating tumor DNA biomarkers to build prediction models. Seven studies reported building prognostic models to predict distant recurrence-free, progression-free, or overall survival. Three discussed building models to predict treatment response using tumor volume, pathologic complete response, or objective response as endpoints. The limited number of articles and the modest cohort sizes reported in these studies attest to the infancy of this field of study. Nonetheless, these studies demonstrate the feasibility of developing multivariable response-predictive and prognostic models using regression and machine learning approaches. Larger studies are warranted to facilitate the building of highly accurate response-predictive and prognostic models that are generalizable to other datasets and clinical settings.

Increased blood draws for ultrasensitive ctDNA and CTCs detection in early breast cancer patients

Early breast cancer patients often experience relapse due to residual disease after treatment. Liquid biopsy is a methodology capable of detecting tumor components in blood, but low concentrations at early stages pose challenges. To detect them, next-generation sequencing has promise but entails complex processes. Exploring larger blood volumes could overcome detection limitations. Herein, a total of 282 high-volume plasma and blood-cell samples were collected for dual ctDNA/CTCs detection using a single droplet-digital PCR assay per patient. ctDNA and/or CTCs were detected in 100% of pre-treatment samples. On the other hand, post-treatment positive samples exhibited a minimum variant allele frequency of 0.003% for ctDNA and minimum cell number of 0.069 CTCs/mL of blood, surpassing previous investigations. Accurate prediction of residual disease before surgery was achieved in patients without a complete pathological response. A model utilizing ctDNA dynamics achieved an area under the ROC curve of 0.92 for predicting response. We detected disease recurrence in blood in the three patients who experienced a relapse, anticipating clinical relapse by 34.61, 9.10, and 7.59 months. This methodology provides an easily implemented alternative for ultrasensitive residual disease detection in early breast cancer patients.

Waiting for the "liquid revolution" in the adjuvant treatment of colon cancer patients: a review of ongoing trials

Since colon cancer has a high rate of shedding of tumour fragments into the blood, several research efforts are now focused on the investigation of the minimal residual disease through the detection of ctDNA to tailor the adjuvant therapy of colon cancer patients and optimize its cost/effectiveness balance. The negative prognostic impact of detectable ctDNA in patients' blood after radical surgery for colon cancer is well established. Several clinical trials adopting heterogeneous designs and techniques are now ongoing to translate promises into daily practice by answering five general questions: i) is a ctDNA-guided decision making efficacious in the post-operative management of colon cancer patients? ii) are de-escalation strategies possible in ctDNA-negative cases? iii) are escalation strategies useful to improve the prognosis of ctDNA-positive patients? iv) when MRD is identified at the end of the adjuvant chemotherapy, is another post-adjuvant systemic therapy efficacious? v) can we exploit ctDNA technologies in the follow up of colon cancer patients? This review focuses on currently ongoing trials and how their results may affect the ctDNA "liquid revolution" of early colon cancer.

Innovation in Non-Invasive Diagnosis and Disease Monitoring for Meningiomas

Meningiomas are tumors of the central nervous system that vary in their presentation, ranging from benign and slow-growing to highly aggressive. The standard method for diagnosing and classifying meningiomas involves invasive surgery and can fail to provide accurate prognostic information. Liquid biopsy methods, which exploit circulating tumor biomarkers such as DNA, extracellular vesicles, micro-RNA, proteins, and more, offer a non-invasive and dynamic approach for tumor classification, prognostication, and evaluating treatment response. Currently, a clinically approved liquid biopsy test for meningiomas does not exist. This review provides a discussion of current research and the challenges of implementing liquid biopsy techniques for advancing meningioma patient care.

Defining an Optimized Workflow for Enriching and Analyzing Residual Tumor Populations Using Intracellular Markers

Tumor relapse is well recognized to arise from treatment-resistant residual populations. Strategies enriching such populations for in-depth downstream analyses focus on tumor-specific surface markers; however, enrichment using intracellular biomarkers remains challenging. Using B-cell lymphoma as an exemplar, we demonstrate feasibility to enrich B-cell lymphoma 2 (BCL2)high populations, a surrogate marker for t(14;18)+ lymphomas, for use in downstream applications. Different fixation protocols were assessed for impact on antibody expression and RNA integrity; glyoxal fixation demonstrated superior results regarding minimal effects on surface and intracellular expression, and RNA quality, compared with alternative fixatives evaluated. Furthermore, t(14;18)+ B cells were effectively detected using intracellular BCL2 overexpression to facilitate tumor cell enrichment. Tumor cell populations were enriched using the cellenONE F1.4 single-cell sorting platform, which detected and dispensed BCL2high-expressing cells directly into library preparation reagents for transcriptome analyses. Sorted glyoxal-fixed cells generated good quality sequencing libraries, with high concordance between live and fixed single-cell transcriptomic profiles, discriminating cell populations predominantly on B-cell biology. Overall, we successfully developed a proof-of-concept workflow employing a robust cell preparation protocol for intracellular markers combined with cell enrichment using the cellenONE platform, providing an alternative to droplet-based technologies when cellular input is low or requires prior enrichment to detect rare populations. This workflow has wider prognostic and therapeutic potential to study residual cells in a pan-cancer setting.

Circulating tumor DNA as prognostic markers of relapsed breast cancer: a systematic review and meta-analysis

Objective

Circulating tumor DNA (ctDNA) is increasingly being used as a potential prognosis biomarker in patients of breast cancer. This review aims to assess the clinical value of ctDNA in outcome prediction in breast cancer patients throughout the whole treatment cycle.

Methods

PubMed, Web of Science, Embase, Cochrane Library, Scopus, and clinical trials.gov were searched from January 2016 to May 2022. Conference abstracts published in last three years were also included. The following search terms were used: ctDNA OR circulating tumor DNA AND breast cancer OR breast carcinoma. Only studies written in English languages were included. The following pre-specified criteria should be met for inclusion: (1) observational studies (prospective or retrospective), randomized control trials, case-control studies and case series studies; (2) patients with breast cancer; (3) ctDNA measurement; (4) clinical outcome data such as objective response rate (ORR), pathological complete response (pCR), relapse-free survival (RFS), overall survival (OS), and so on. The random-effect model was preferred considering the potential heterogeneity across studies. The primary outcomes included postoperative short-term outcomes (ORR and pCR) and postoperative long-term outcomes (RFS, OS, and relapse). Secondary outcomes focused on ctDNA detection rate.

Results

A total of 30 studies, comprising of 19 cohort studies, 2 case-control studies and 9 case series studies were included. The baseline ctDNA was significantly negatively associated with ORR outcome (Relative Risk [RR] = 0.65, 95% confidence interval [CI]: 0.50-0.83), with lower ORR in the ctDNA-positive group than ctDNA-negative group. ctDNA during neoadjuvant therapy (NAT) treatment was significantly associated with pCR outcomes (Odds Ratio [OR] = 0.15, 95% CI: 0.04-0.54). The strong association between ctDNA and RFS or relapse outcome was significant across the whole treatment period, especially after the surgery (RFS: Hazard Ratio [HR] = 6.74, 95% CI: 3.73-12.17; relapse outcome: RR = 7.11, 95% CI: 3.05-16.53), although there was heterogeneity in these results. Pre-operative and post-operative ctDNA measurements were significantly associated with OS outcomes (pre-operative: HR = 2.03, 95% CI: 1.12-3.70; post-operative: HR = 6.03, 95% CI: 1.31-27.78).

Conclusions

In this review, ctDNA measurements at different timepoints are correlated with evaluation indexes at different periods after treatment. The ctDNA can be used as an early potential postoperative prognosis biomarker in breast cancer, and also as a reference index to evaluate the therapeutic effect at different stages.

Circulating Nucleic Acids in Colorectal Cancer: Diagnostic and Prognostic Value

Colorectal cancer (CRC) is the third most prevalent cancer in the world and the fourth leading cause of cancer-related mortality. DNA (cfDNA/ctDNA) and RNA (cfRNA/ctRNA) in the blood are promising noninvasive biomarkers for molecular profiling, screening, diagnosis, treatment management, and prognosis of CRC. Technological advancements that enable precise detection of both genetic and epigenetic abnormalities, even in minute quantities in circulation, can overcome some of these challenges. This review focuses on testing for circulating nucleic acids in the circulation as a noninvasive method for CRC detection, monitoring, detection of minimal residual disease, and patient management. In addition, the benefits and drawbacks of various diagnostic techniques and associated bioinformatics tools have been detailed.

Association of circulating tumor HPV16DNA levels and quantitative PET parameters in patients with HPV-positive head and neck squamous cell carcinoma

Circulating tumor DNA (ctDNA), which circulates in the blood after being shed from cancer cells in the body, has recently gained attention as an excellent tumor marker. The purpose of this study was to evaluate whether ct human papillomavirus (HPV) 16 DNA (ctHPV16DNA) levels were associated with quantitative PET parameters in patients with HPV-positive head and neck (HN) squamous cell carcinoma (SCC). Fifty patients with oropharyngeal SCC (OPSCC) and 5 with SCC of unknown primary (SCCUP) before treatment were included. They all underwent blood sampling to test ctHPV16DNA levels and FDG PET-CT examinations. Quantitative PET parameters included SUVmax, metabolic tumor volume (MTV), MTV of whole-body lesions (wbMTV), and 56 texture features. ctHPV16DNA levels were compared to texture features of primary tumors in OPSCC patients (Group A) or the largest primary or metastatic lymph node lesions in OPSCC and SCCUP patients (Group B) and to other PET parameters. Spearman rank correlation test and multiple regression analysis were used to confirm the associations between ctHPV16DNA levels and PET parameters. ctHPV16DNA levels moderately correlated with wbMTV, but not with SUVmax or MTV in Groups A and B. ctHPV16DNA levels exhibited a weak negative correlation with low gray-level zone emphasis in Groups A and B. Multiple regression analysis revealed that wbMTV and high gray-level zone emphasis were the significant factors for ctHPV16DNA levels in Group B. These results were not observed in Group A. This study demonstrated that ctHPV16DNA levels correlated with the whole-body tumor burden and tumor heterogeneity visualized on FDG PET-CT in patients with HPV-positive HNSCC.

Serial circulating tumor DNA profiling predicts tumor recurrence after liver transplantation for liver cancer

BACKGROUND

Minimal residual disease (MRD) is proposed to be responsible for tumor recurrence. The role of circulating tumor DNA (ctDNA) to detect MRD, monitor recurrence, and predict prognosis in liver cancer patients undergoing liver transplantation (LT) remains unrevealed.

METHODS

Serial blood samples were collected to profile ctDNA mutational changes. Baseline ctDNA mutational profiles were compared with those of matched tumor tissues. Correlations between ctDNA status and recurrence rate (RR) and recurrence-free survival (RFS) were analyzed, respectively. Dynamic change of ctDNA was monitored to predict tumor recurrence.

RESULTS

Baseline mutational profiles of ctDNA were highly concordant with those of tumor tissues (median, 89.85%; range 46.2-100%) in the 74 patients. Before LT, positive ctDNA status was associated with higher RR (31.7% vs 11.5%; p = 0.001) and shorter RFS than negative ctDNA status (17.8 vs 19.4 months; p = 0.019). After LT, the percentage of ctDNA positivity decreased (17.6% vs 47.0%; p < 0.001) and patients with positive ctDNA status had higher RR (46.2% vs 21.3%; p < 0.001) and shorter RFS (17.2 vs 19.2 months; p = 0.010). Serial ctDNA profiling demonstrated patients with decreased or constant negative ctDNA status had lower RR (33.3% vs 50.0%; p = 0.015) and favorable RFS (18.2 vs 15.0 months, p = 0.003) than those with increased or constant positive ctDNA status. Serial ctDNA profiling predicted recurrence months ahead of imaging evidence and serum tumor biomarkers.

CONCLUSIONS

ctDNA could effectively detect MRD and predict tumor recurrence in liver cancer patients undergone LT.

Tumor-derived cell-free DNA and circulating tumor cells: partners or rivals in metastasis formation?

The origin of metastases is a topic that has sparked controversy. Despite recent advancements, metastatic disease continues to pose challenges. The first admitted model of how metastases develop revolves around cells breaking away from the primary tumor, known as circulating tumor cells (CTCs). These cells survive while circulating through the bloodstream and subsequently establish themselves in secondary organs, a process often referred to as the "metastatic cascade". This intricate and dynamic process involves various steps, but all the mechanisms behind metastatic dissemination are not yet comprehensively elucidated. The "seed and soil" theory has shed light on the phenomenon of metastatic organotropism and the existence of pre-metastatic niches. It is now established that these niches can be primed by factors secreted by the primary tumor before the arrival of CTCs. In particular, exosomes have been identified as important contributors to this priming. Another concept then emerged, i.e. the "genometastasis" theory, which challenged all other postulates. It emphasizes the intriguing but promising role of cell-free DNA (cfDNA) in metastasis formation through oncogenic formation of recipient cells. However, it cannot be ruled out that all these theories are intertwined. This review outlines the primary theories regarding the metastases formation that involve CTCs, and depicts cfDNA, a potential second player in the metastasis formation. We discuss the potential interrelationships between CTCs and cfDNA, and propose both in vitro and in vivo experimental strategies to explore all plausible theories.

Advancements in Biotechnology and Stem Cell Therapies for Breast Cancer Patients

This comprehensive review article examines the integration of biotechnology and stem cell therapy in breast cancer diagnosis and treatment. It discusses the use of biotechnological tools such as liquid biopsies, genomic profiling, and imaging technologies for accurate diagnosis and monitoring of treatment response. Stem cell-based approaches, their role in modeling breast cancer progression, and their potential for breast reconstruction post-mastectomy are explored. The review highlights the importance of personalized treatment strategies that combine biotechnological tools and stem cell therapies. Ethical considerations, challenges in clinical translation, and regulatory frameworks are also addressed. The article concludes by emphasizing the potential of integrating biotechnology and stem cell therapy to improve breast cancer outcomes, highlighting the need for continued research and collaboration in this field.

Cancer cell seeding density as a mechanism of chemotherapy resistance: a novel cancer cell density index based on IC50-Seeding Density Slope (ISDS) to assess chemosensitivity

Although the 50% inhibitory concentration (IC50) is a commonly used measurement of chemosensitivity in cancer cells, it has been known to vary with the density of the treated cells (in that more densely seeded cells are more resistant to chemotherapeutic agents). Indeed, density-dependent chemoresistance may be a significant independent mechanism of therapy resistance. We examine the nature of cell density-dependent chemoresistance and explore possible underlying mechanisms. CellTiter-Glo assays and ethidium homodimer staining revealed that response to chemotherapy is density-dependent in all cancer cell lines tested. Our results prompted us to develop a novel cancer cell seeding density index of chemosensitivity, the ISDS (IC50-Seeding Density Slope), which we propose can serve as an improved method of analyzing how cancer cells respond to chemotherapeutic treatment compared to the widely-used IC50. Furthermore, western blot analysis suggests that levels of autophagy and apoptotic markers are modulated by cancer cell density. Cell viability experiments using the autophagy inhibitor chloroquine showed that chloroquine's efficacy was reduced at higher cell densities and that chloroquine and cisplatin exhibited synergy at both higher and lower cell densities in TOV-21G cells. We discuss alternative mechanisms of density-dependent chemoresistance and in vivo/clinical applications, including challenges of adjuvant chemotherapy and minimal residual disease. Taken together, our findings show that cell density is a significant contributor in shaping cancer chemosensitivity, that the ISDS (aka the Ujwal Punyamurtula/Wafik El-Deiry or Ujwal-WAF Index) can be used to effectively assess cell viability and that this phenomenon of density-dependent chemoresistance may be leveraged for a variety of biologic and cancer therapeutic applications.

Harnessing liquid biopsies: Exosomes and ctDNA as minimally invasive biomarkers for precision cancer medicine

Liquid biopsies have emerged as groundbreaking tools for minimally invasive monitoring of cancer, encompassing the analysis of Cell-Free DNA (cfDNA), circulating tumor DNA (ctDNA) and exosomes. This paradigm shift offers an emerging approach for understanding tumor dynamics, treatment responses, and disease progression. Leveraging advancements in molecular biology and technology, liquid biopsies enable clinicians to gain intricate insights from peripheral blood, thereby transforming the landscape of cancer care. This review describes the clinical impact, technological innovations, and recent evidence surrounding the integration of ctDNA and exosome analysis in cancer monitoring. Through early detection, real-time treatment response assessment, and the tracking of minimal residual disease, liquid biopsies have redefined the standards of precision oncology. Key advancements in ctDNA analysis, such as high-throughput sequencing and digital PCR, empower the detection of actionable mutations with high sensitivity. Concurrently, the characterization of exosomal cargo, facilitated by next-generation sequencing and mass spectrometry, unveils the molecular nuances of tumors. Recent studies underscore the utility of these approaches, demonstrating their efficacy in predicting relapse, guiding therapeutic decisions, and ultimately improving patient outcomes. As the field continues to evolve, liquid biopsies hold promise not only as diagnostic tools but also as agents of personalized medicine, enabling precise navigation of the intricate landscape of cancer with minimally invasiveness.

Tumour excisional surgery, anaesthetic-analgesic techniques, and oncologic outcomes: a narrative review

Cancer is a growing global burden; there were an estimated 18 million new cancer diagnoses worldwide in 2020. Excisional surgery remains one of the main treatments for solid organ tumours in cancer patients and is potentially curative. Cancer- and surgery-induced inflammatory processes can facilitate residual tumour cell survival, growth, and subsequent recurrence. However, it has been hypothesised that anaesthetic and analgesic techniques during surgery might influence the risk of cancer recurrence. This narrative review aims to provide an updated summary of recent observational studies and new randomised controlled clinical trials on whether certain specific anaesthetic and analgesic techniques or perioperative interventions during tumour resection surgery of curative intent materially affect long-term oncologic outcomes.

Current state and challenges of emerging biomarkers for immunotherapy in hepatocellular carcinoma (Review)

Hepatocellular carcinoma (HCC) is the most prevalent form of primary liver cancer. According to the American Cancer Society, among patients diagnosed with advanced liver cancer, HCC has the sixth-highest incident rate, resulting in a poor prognosis. Surgery, radiofrequency ablation, transcatheter arterial chemoembolization, radiation, chemotherapy, targeted therapy and immunotherapy are the current treatment options available. Immunotherapy, which has emerged as an innovative treatment strategy over the past decade, is serving a vital role in the treatment of advanced liver cancer. Since only a small number of individuals can benefit from immunotherapy, biomarkers are required to help clinicians identify the target populations for this precision medicine. These biomarkers, such as PD-1/PD-L1, tumor mutational burden and circulating tumor DNA, can be used to investigate interactions between immune checkpoint inhibitors and tumors. The present review summarizes information on the currently available biomarkers used for immunotherapy and the challenges that are present.

Prognostic utility of preoperative and postoperative KRAS-mutated circulating tumor DNA (ctDNA) in resected pancreatic ductal adenocarcinoma: A systematic review and meta-analysis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a challenging disease, with surgery being the only possible cure. However, despite surgery, the majority of patients experience recurrence. Recent evidence suggests that perioperative KRAS-mutated circulating tumor DNA (ctDNA) may have prognostic value. Therefore, we conducted a systematic review and meta-analysis to explore the prognostic significance of preoperative and postoperative KRAS-mutated ctDNA testing in resected PDAC.

METHODS

We searched PubMed/MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases for studies that reported the effect of preoperative and postoperative KRAS-mutated ctDNA on overall survival (OS) and/or relapse-free survival (RFS) in resected PDAC. We used a random-effects model to determine the pooled OS and RFS hazard ratios (HR) and their corresponding 95 % confidence intervals (CI).

RESULTS

We identified 15 studies (868 patients) eligible for analysis. In the preoperative setting, positive ctDNA correlated with worse RFS in 8 studies (HR, 2.067; 95 % CI, 1.346-3.174, P < 0.001) and worse OS in 10 studies (HR, 2.170; 95 % CI, 1.451-3.245, P < 0.001) compared to negative ctDNA. In the postoperative setting, positive ctDNA correlated with worse RFS across 9 studies (HR, 3.32; 95 % CI, 2.19-5.03, P < 0.001) and worse OS in 6 studies (HR, 6.62; 95 % CI, 2.18-20.16, P < 0.001) compared to negative ctDNA.

CONCLUSION

Our meta-analysis supports the utility of preoperative and postoperative KRAS-mutated ctDNA testing as a prognostic marker for resected PDAC. Further controlled studies are warranted to confirm these results and to investigate the potential therapeutic implications of positive KRAS-mutated ctDNA.

Circulating tumour DNA testing in metastatic breast cancer: Integration with tissue testing

Breast cancer biomarker profiling predominantly relies on tissue testing (surgical and/or biopsy samples). However, the field of liquid biopsy, particularly the analysis of circulating tumour DNA (ctDNA), has witnessed remarkable progress and continues to evolve rapidly. The incorporation of ctDNA-based testing into clinical practice is creating new opportunities for patients with metastatic breast cancer (MBC). ctDNA offers advantages over conventional tissue analyses, as it reflects tumour heterogeneity and enables multiple serial biopsies in a minimally invasive manner. Thus, it serves as a valuable complement to standard tumour tissues and, in certain instances, may even present a potential alternative approach. In the context of MBC, ctDNA testing proves highly informative in the detection of disease progression, monitoring treatment response, assessing actionable biomarkers, and identifying mechanisms of resistance. Nevertheless, ctDNA does exhibit inherent limitations, including its generally low abundance, necessitating timely blood samplings and rigorous management of the pre-analytical phase. The development of highly sensitive assays and robust bioinformatic tools has paved the way for reliable ctDNA analyses. The time has now come to establish how ctDNA and tissue analyses can be effectively integrated into the diagnostic workflow of MBC to provide patients with the most comprehensive and accurate profiling. In this manuscript, we comprehensively analyse the current methodologies employed in ctDNA analysis and explore the potential benefits arising from the integration of tissue and ctDNA testing for patients diagnosed with MBC.

Circulating Tumor DNA from Ascites as an alternative to tumor sampling for genomic profiling in ovarian cancer patients

Genomic testing is crucial for the management of ovarian cancer. DNA from biopsies at diagnostic laparoscopies or interval debulking surgery after neoadjuvant chemotherapy, has a high failure rate. At relapse, biopsies may not be feasible. The aim of our study was to evaluate the feasibility and usefulness of measuring genomic instability score (GIS) on cell-free DNA (cfDNA) from ascites.Patients enrolled in a prospective study (NCT03010124) consented to analysis of biological samples. CfDNA was extracted from 1 to 4 ml of double-centrifuged fresh ascites. Targeted Next-generation sequencing (NGS) including TP53 mutation (TP53m) was performed on cfDNA to confirm the presence of tumor cfDNA. Single Nucleotide Polymorphism Array estimating somatic copy number alterations (SCNA) was performed to calculate GIS for Homologous-Recombination deficiency (HRD).Twenty nine ascites were collected from 20 patients with suspected or confirmed OC. 93% (27/29) samples had detectable cfDNA (median 1120 ng [24-5732]) even when obtained during chemotherapy. A deleterious mutation was identified in 100%, with high allelic frequencies (median 60% [3.3-87%]), confirming that cfDNA was tumoral. SCNA analyses on 17 patients showed 11 high GIS, and 6 low GIS. 4 patients with confirmed BRCA mutation had a high GIS on ascites. When available from the same patient, SCNA profiles on ascites and tumor were superimposable.Ascites is frequent at diagnosis and relapse and yields large amounts of tumoral cfDNA. SCNA analysis on ascitic cfDNA is feasible and can detect the same HRD scar as tumor testing. Ascites could provide an alternative to tumor sampling for HRD and BRCA testing.