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

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.

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.

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.

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.

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.

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Key Words

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

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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

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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.

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.

Transmission of Lung Adenocarcinoma From a Single Donor in 2 Transplant Recipients: A Case Report With Literature Review

Malignancies transmitted to recipients during solid organ transplants carry significant morbidity and mortality. We present 2 cases of adenocarcinoma of donor lung origin transmitted via liver and kidney transplant from a single donor. Both recipients developed metastatic adenocarcinoma of lung origin with p.L858R mutation in the epidermal growth factor receptor gene and a microsatellite signature of donor origin. Osimertinib was trialed in the liver recipient; however, it was discontinued because of hepatotoxicity and disease progression. Standard donor screening protocols limit malignancy transmission but do not include multicancer detection assays. As these technologies evolve, they may be implemented in donor screening.

Potential biomarkers for immunotherapy in non-small-cell lung cancer

For individuals with advanced or metastatic non-small cell lung cancer (NSCLC), the primary treatment is platinum-based doublet chemotherapy. Immune checkpoint inhibitors (ICIs), primarily PD-1/PD-L1 and CTLA-4, have been found to be effective in patients with NSCLC who have no EGFR/ALK mutations. Furthermore, ICIs are considered a standard therapy. The quantity of fresh immunogenic antigens discovered by cytotoxic T cells was measured by PD-L1 expression and tumor mutational burden (TMB), which were the first biomarkers assessed in clinical trials. However, immunotherapy did not have response efficacy markers similar to targeted therapy, highlighting the significance of newly developed biomarkers. This investigation aims to review the research on immunotherapy for NSCLC, focusing primarily on the impact of biomarkers on efficacy prediction to determine whether biomarkers may be utilized to evaluate the effectiveness of immunotherapy.

Clinical significance of circulating tumor DNA in localized non-small cell lung cancer: a systematic review and meta-analysis

Circulating tumor DNA (ctDNA) detection holds promise for genetic analyses and quantitative assessment of tumor burden. A systematic review and meta-analysis were conducted to investigate the clinical relevance of ctDNA among patients with localized non-small cell lung cancer (NSCLC). PubMed, EMBASE, and the Cochrane Library were searched for eligible studies published from January 2001 to April 2022. After quality assessments and data extraction, diagnostic accuracy variables and prognostic data were calculated and analyzed by Meta-Disc 1.4, Review Manager 5.4.1, and STATA 17.0. Eight prospective studies and one retrospective study including 784 patients with localized NSCLC were used in our meta-analysis. The pooled sensitivity and specificity of ctDNA for minimal residual disease (MRD) detection were 0.58 and 0.93, respectively. The pooled positive and negative likelihood ratios were 7.57 (95% confidence interval (CI) 2.84-20.20) and 0.45 (95% CI 0.37-0.55), respectively. The area under the summary receiver operating characteristic curve was 0.8967, and the diagnostic odds ratio was 32.26 (95% CI 14.63-71.12). In addition, both precurative-treatment and postcurative-treatment ctDNA positivity was associated with worse recurrence-free survival (hazard ratio (HR), 3.82 and 8.32, respectively) and worse overall survival (HR, 3.82 and 4.73, respectively). The findings suggested that ctDNA detection has beneficial utility regarding MRD detection specificity; moreover, positive ctDNA was associated with poor prognosis in patients with localized NSCLC.

Circulating tumor cells in cancer-risk populations as a cancer interception tool

Cancer interception (CI) is a new approach to cancer prevention and treatment in a cancer-risk population that aims to detect and treat pre-tumoral stages. It has several potential advantages over traditional cancer diagnosis and monitoring methods because it is non-invasive, making it less painful and risky than conventional biopsy procedures. The circulating tumor cells (CTCs), liquid biopsy family members, are essential for the CI approach; then, the liquid biopsy (LB) is used as a CI tool. LB can be performed frequently because of its easy sampling and early pathological stages, which allow repeated non-invasive monitoring of cancer progression and response to treatment. CTCs have been found in the bloodstream of several types of cancer patients, including in early-stage cancer and premalignant lesions, suggesting a tumor development role in cancer's early stages. This chapter will present foundational scientific studies addressing CI and the clinical impact of CTC screening in a population at risk for cancer.

Pretreatment Tumor Growth Rate and Radiological Response as Predictive Markers of Pathological Response and Survival in Patients with Resectable Lung Cancer Treated by Neoadjuvant Treatment

INTRODUCTION

Predictive biomarkers associated with pathological response, progression precluding surgery, and/or recurrence after surgery are needed for patients with resectable non-small cell lung carcinoma (NSCLC) treated by neoadjuvant treatment. We evaluated the clinical impact of the pretreatment tumor growth rate (TGR0) and radiological response for patients with resectable NSCLC treated with neoadjuvant therapies.

METHODS

Consecutive patients with resectable stage IB (≥4 cm) to IIIA NSCLC treated by neoadjuvant platinum-doublet chemotherapy with or without nivolumab at our tertiary center were retrospectively analyzed. TGR0 and RECIST objective responses were determined. Multivariable analyses identified independent predictors of event-free survival (EFS), overall survival (OS), and major pathological response (MPR).

RESULTS

Between November 2017 and December 2022, 32 patients (mean [SD] age, 63.8 [8.0] years) were included. At a median follow-up of 54.8 months (95% CI, 42.3-60.4 months), eleven patients (34%) experienced progression or recurrence, and twelve deaths (38%) were recorded. The TGR0 cutoff of 30%/month remained the only independent factor associated with EFS (HR = 0.04; 95% CI, 0.01-0.3; p = 0.003) and OS (HR = 0.2; 95% CI, 0.03-0.7; p = 0.01). The TGR0 cut-off had a mean time-dependent AUC of 0.83 (95% CI, 0.64-0.95) and 0.80 (95% CI, 0.62-0.97) for predicting EFS and OS, respectively. Fifteen of 26 resection cases (58%) showed MPR including nine with pathological complete responses (35%). Only the objective response of the primary tumor was associated with MPR (OR = 27.5; 95% CI, 2.6-289.1; p = 0.006).

CONCLUSIONS

Assessment of TGR0 can identify patients who should benefit from neoadjuvant treatment. A tumor objective response might be a predictor of MPR after neoadjuvant treatment, which will help to adapt surgical management.

Potential value of ctDNA monitoring in metastatic HR + /HER2 - breast cancer: longitudinal ctDNA analysis in the phase Ib MONALEESASIA trial

BACKGROUND

There is increasing interest in the use of liquid biopsies, but data on longitudinal analyses of circulating tumor DNA (ctDNA) remain relatively limited. Here, we report a longitudinal ctDNA analysis of MONALEESASIA, a phase Ib trial evaluating the efficacy and safety of ribociclib plus endocrine therapy (ET) in Asian patients with hormone receptor-positive, human epidermal growth factor receptor-2-negative advanced breast cancer.

METHODS

MONALEESASIA enrolled premenopausal and postmenopausal Japanese and postmenopausal non-Japanese Asian patients. All patients received ribociclib with ET (letrozole, fulvestrant, or tamoxifen with goserelin). ctDNA was analyzed using a targeted next-generation sequencing panel of 572 cancer-related genes and correlated by best overall response (BOR).

RESULTS

Five hundred seventy-four cell-free DNA samples from 87 patients were tested. The most frequently altered genes at baseline included PIK3CA (29%) and TP53 (22%). Treatment with ribociclib plus ET decreased ctDNA in most patients at the first on-treatment time point, regardless of dose or ET partner. Patients with partial response and stable disease had lower ctDNA at baseline that remained low until data cutoff if no progressive disease occurred. Most patients with progressive disease as the best response had higher ctDNA at baseline that remained high at the end of treatment. For patients with partial response and stable disease with subsequent progression, ctDNA increased towards the end of treatment in most patients, with a median lead time of 83 days (14-309 days). In some patients with BOR of partial response who experienced disease progression later, specific gene alterations and total ctDNA fraction increased; this was sometimes observed concurrently with the development of new lesions without a change in target lesion size. Patients with alterations in PIK3CA and TP53 at baseline had shorter median progression-free survival compared with patients with wild-type PIK3CA and TP53, 12.7 and 7.3 months vs 19.2 and 19.4 months, respectively (P = .016 and P = .0001, respectively).

CONCLUSIONS

Higher ctDNA levels and PIK3CA and TP53 alterations detected at baseline were associated with inferior outcomes. On-treatment ctDNA levels were associated with different patterns based on BOR. Longitudinal tracking of ctDNA may be useful for monitoring tumor status and detection of alterations with treatment implications.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02333370 . Registered on January 7, 2015.

ctDNA as a novel and promising approach for cancer diagnosis: a focus on hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most prevalent forms of cancer worldwide. Therefore, it is essential to diagnose and treat HCC patients promptly. As a novel discovery, circulating tumor DNA (ctDNA) can be used to analyze the tumor type and the cancer location. Additionally, ctDNA assists the cancer stage determination, which enables medical professionals to provide patients with the most appropriate treatment. This review will discuss the HCC-related mutated genes diagnosed by ctDNA. In addition, we will introduce the different and the most appropriate ctDNA diagnosis approaches based on the facilities.

Minimal residual disease in solid tumors: an overview

Minimal residual disease (MRD) is termed as the small numbers of remnant tumor cells in a subset of patients with tumors. Liquid biopsy is increasingly used for the detection of MRD, illustrating the potential of MRD detection to provide more accurate management for cancer patients. As new techniques and algorithms have enhanced the performance of MRD detection, the approach is becoming more widely and routinely used to predict the prognosis and monitor the relapse of cancer patients. In fact, MRD detection has been shown to achieve better performance than imaging methods. On this basis, rigorous investigation of MRD detection as an integral method for guiding clinical treatment has made important advances. This review summarizes the development of MRD biomarkers, techniques, and strategies for the detection of cancer, and emphasizes the application of MRD detection in solid tumors, particularly for the guidance of clinical treatment.

Longitudinal Monitoring of Circulating Tumor DNA to Assess the Efficacy of Immune Checkpoint Inhibitors in Patients With Advanced Genitourinary Malignancies

PURPOSE

Circulating tumor DNA (ctDNA) detection in blood has emerged as a prognostic and predictive biomarker demonstrating improved assessment of treatment response in patients receiving immune checkpoint inhibitors (ICIs). Here, we performed a pilot study to support the role of ctDNA for longitudinal treatment response monitoring in patients with advanced genitourinary (GU) malignancies receiving ICIs.

MATERIALS AND METHODS

Patients with histologically confirmed advanced GU malignancies were prospectively enrolled. All eligible patients received ICI treatment for at least 12 weeks, followed by serial collection of blood samples every 6-8 weeks and conventional scans approximately every 12 weeks until disease progression. ctDNA analysis was performed using Signatera, a tumor-informed multiplex-polymerase chain reaction next-generation sequencing assay. Overall, the objective response rate (ORR) was reported and its association with ctDNA status was evaluated. Concordance rate between ctDNA dynamics and conventional imaging was also assessed.

RESULTS

ctDNA analysis was performed on 98 banked plasma samples from 20 patients (15 renal, four urothelial, and one prostate). The median follow-up from the time of initiation of ICI to progressive disease (PD) or data cutoff was 67.7 weeks (range, 19.6-169.6). The ORR was 70% (14/20). Eight patients ultimately developed PD. The overall concordance between ctDNA dynamics and radiographic response was observed in 83% (15/18) of patients. Among the three patients with discordant results, two developed CNS metastases and one progressed with extracranial systemic disease while ctDNA remained undetectable.

CONCLUSION

In this pilot study, longitudinal ctDNA analysis for monitoring response to ICI in patients with advanced GU tumors was feasible. Larger prospective studies are warranted to validate the utility of ctDNA as an ICI response monitoring tool in patients with advanced GU malignancies.

Practical recommendations for using ctDNA in clinical decision making

The continuous improvement in cancer care over the past decade has led to a gradual decrease in cancer-related deaths. This is largely attributed to improved treatment and disease management strategies. Early detection of recurrence using blood-based biomarkers such as circulating tumour DNA (ctDNA) is being increasingly used in clinical practice. Emerging real-world data shows the utility of ctDNA in detecting molecular residual disease and in treatment-response monitoring, helping clinicians to optimize treatment and surveillance strategies. Many studies have indicated ctDNA to be a sensitive and specific biomarker for recurrence. However, most of these studies are largely observational or anecdotal in nature, and peer-reviewed data regarding the use of ctDNA are mainly indication-specific. Here we provide general recommendations on the clinical utility of ctDNA and how to interpret ctDNA analysis in different treatment settings, especially in patients with solid tumours. Specifically, we provide an understanding around the implications, strengths and limitations of this novel biomarker and how to best apply the results in clinical practice.

Detection of endometrial cancer using tampon-based collection and methylated DNA markers

OBJECTIVE

Alterations in DNA methylation are early events in endometrial cancer (EC) development and may have utility in EC detection via tampon-collected vaginal fluid.

METHODS

For discovery, DNA from frozen EC, benign endometrium (BE), and benign cervicovaginal (BCV) tissues underwent reduced representation bisulfite sequencing (RRBS) to identify differentially methylated regions (DMRs). Candidate DMRs were selected based on receiver operating characteristic (ROC) discrimination, methylation level fold-change between cancers and controls, and absence of background CpG methylation. Methylated DNA marker (MDM) validation was performed using qMSP on DNA from independent EC and BE FFPE tissue sets. Women ≥45 years of age with abnormal uterine bleeding (AUB) or postmenopausal bleeding (PMB) or any age with biopsy-proven EC self-collected vaginal fluid using a tampon prior to clinically indicated endometrial sampling or hysterectomy. Vaginal fluid DNA was assayed by qMSP for EC-associated MDMs. Random forest modeling analysis was performed to generate predictive probability of underlying disease; results were 500-fold in-silico cross-validated.

RESULTS

Thirty-three candidate MDMs met performance criteria in tissue. For the tampon pilot, 100 EC cases were frequency matched by menopausal status and tampon collection date to 92 BE controls. A 28-MDM panel highly discriminated between EC and BE (96% (95%CI 89-99%) specificity; 76% (66-84%) sensitivity (AUC 0.88). In PBS/EDTA tampon buffer, the panel yielded 96% (95% CI 87-99%) specificity and 82% (70-91%) sensitivity (AUC 0.91).

CONCLUSION

Next generation methylome sequencing, stringent filtering criteria, and independent validation yielded excellent candidate MDMs for EC. EC-associated MDMs performed with promisingly high sensitivity and specificity in tampon-collected vaginal fluid; PBS-based tampon buffer with added EDTA improved sensitivity. Larger tampon-based EC MDM testing studies are warranted.

Circulating Tumor DNA as a Minimal Residual Disease Assessment and Recurrence Risk in Patients Undergoing Curative-Intent Resection with or without Adjuvant Chemotherapy in Colorectal Cancer: A Systematic Review and Meta-Analysis

Emerging data have suggested that circulating tumor DNA (ctDNA) can be a reliable biomarker for minimal residual disease (MRD) in CRC patients. Recent studies have shown that the ability to detect MRD using ctDNA assay after curative-intent surgery will change how to assess the recurrence risk and patient selection for adjuvant chemotherapy. We performed a meta-analysis of post-operative ctDNA in stage I-IV (oligometastatic) CRC patients after curative-intent resection. We included 23 studies representing 3568 patients with evaluable ctDNA in CRC patient post-curative-intent surgery. Data were extracted from each study to perform a meta-analysis using RevMan 5.4. software. Subsequent subgroup analysis was performed for stages I-III and oligometastatic stage IV CRC patients. Results showed that the pooled hazard ratio (HR) for recurrence-free survival (RFS) in post-surgical ctDNA-positive versus -negative patients in all stages was 7.27 (95% CI 5.49-9.62), p < 0.00001. Subgroup analysis revealed pooled HRs of 8.14 (95% CI 5.60-11.82) and 4.83 (95% CI 3.64-6.39) for stages I-III and IV CRC, respectively. The pooled HR for RFS in post-adjuvant chemotherapy ctDNA-positive versus -negative patients in all stages was 10.59 (95% CI 5.59-20.06), p < 0.00001. Circulating tumor DNA (ctDNA) analysis has revolutionized non-invasive cancer diagnostics and monitoring, with two primary forms of analysis emerging: tumor-informed techniques and tumor-agnostic or tumor-naive techniques. Tumor-informed methods involve the initial identification of somatic mutations in tumor tissue, followed by the targeted sequencing of plasma DNA using a personalized assay. In contrast, the tumor-agnostic approach performs ctDNA analysis without prior knowledge of the patient's tumor tissue molecular profile. This review highlights the distinctive features and implications of each approach. Tumor-informed techniques enable the precise monitoring of known tumor-specific mutations, leveraging the sensitivity and specificity of ctDNA detection. Conversely, the tumor-agnostic approach allows for a broader genetic and epigenetic analysis, potentially revealing novel alterations and enhancing our understanding of tumor heterogeneity. Both approaches have significant implications for personalized medicine and improved patient outcomes in the field of oncology. The subgroup analysis based on the ctDNA method showed pooled HRs of 8.66 (95% CI 6.38-11.75) and 3.76 (95% CI 2.58-5.48) for tumor-informed and tumor-agnostic, respectively. Our analysis emphasizes that post-operative ctDNA is a strong prognostic marker of RFS. Based on our results, ctDNA can be a significant and independent predictor of RFS. This real-time assessment of treatment benefits using ctDNA can be used as a surrogate endpoint for the development of novel drugs in the adjuvant setting.

Clinical application of liquid biopsy based on circulating tumor DNA in non-small cell lung cancer

Lung cancer is a widely occurring and deadly malignancy, with high prevalence rates in China and across the globe. Specifically, non-small cell lung cancer (NSCLC) represents about 85% of all lung cancer cases. The 5-year disease-free survival rate after surgery for stage IB-IIIB NSCLC patients (disease-free survival, DFS) has notably declined from 73% to 13%. Early detection of abnormal cancer molecules and subsequent personalized treatment plans are the most effective ways to address this problem. Liquid biopsy, surprisingly, enables safe, accurate, non-invasive, and dynamic tracking of disease progression. Among the various modalities, circulating tumor DNA (ctDNA) is the most commonly used liquid biopsy modality. ctDNA serves as a credible "liquid biopsy" diagnostic tool that, to a certain extent, overcomes tumor heterogeneity and harbors genetic mutations in malignancies, thereby providing early information on tumor genetic alterations. Despite considerable academic interest in the clinical significance of ctDNA, consensus on its utility remains lacking. In this review, we assess the role of ctDNA testing in the diagnosis and management of NSCLC as a reference for clinical intervention in this disease. Lastly, we examine future directions to optimize ctDNA for personalized therapy.

Private Payer and Medicare Coverage Policies for Use of Circulating Tumor DNA Tests in Cancer Diagnostics and Treatment

BACKGROUND

Circulating tumor DNA (ctDNA) is used to select initial targeted therapy, identify mechanisms of therapeutic resistance, and measure minimal residual disease (MRD) after treatment. Our objective was to review private and Medicare coverage policies for ctDNA testing.

METHODS

Policy Reporter was used to identify coverage policies (as of February 2022) from private payers and Medicare Local Coverage Determinations (LCDs) for ctDNA tests. We abstracted data regarding policy existence, ctDNA test coverage, cancer types covered, and clinical indications. Descriptive analyses were performed by payer, clinical indication, and cancer type.

RESULTS

A total of 71 of 1,066 total policies met study inclusion criteria, of which 57 were private policies and 14 were Medicare LCDs; 70% of private policies and 100% of Medicare LCDs covered at least one indication. Among 57 private policies, 89% specified a policy for at least 1 clinical indication, with coverage for ctDNA for initial treatment selection most common (69%). Of 40 policies addressing progression, coverage was provided 28% of the time, and of 20 policies addressing MRD, coverage was provided 65% of the time. Non-small cell lung cancer (NSCLC) was the cancer type most frequently covered for initial treatment (47%) and progression (60%). Among policies with ctDNA coverage, coverage was restricted to patients without available tissue or in whom biopsy was contraindicated in 91% of policies. MRD was commonly covered for hematologic malignancies (30%) and NSCLC (25%). Of the 14 Medicare LCD policies, 64% provided coverage for initial treatment selection and progression, and 36% for MRD.

CONCLUSIONS

Some private payers and Medicare LCDs provide coverage for ctDNA testing. Private payers frequently cover testing for initial treatment, especially for NSCLC, when tissue is insufficient or biopsy is contraindicated. Coverage remains variable across payers, clinical indications, and cancer types despite inclusion in clinical guidelines, which could impact delivery of effective cancer care.

Soluble biomarkers to predict clinical outcomes in non-small cell lung cancer treated by immune checkpoints inhibitors

Lung cancer remains the first cause of cancer-related death despite many therapeutic innovations, including immune checkpoint inhibitors (ICI). ICI are now well used in daily practice at late metastatic stages and locally advanced stages after a chemo-radiation. ICI are also emerging in the peri-operative context. However, all patients do not benefit from ICI and even suffer from additional immune side effects. A current challenge remains to identify patients eligible for ICI and benefiting from these drugs. Currently, the prediction of ICI response is only supported by Programmed death-ligand 1 (PD-L1) tumor expression with perfectible results and limitations inherent to tumor-biopsy specimen analysis. Here, we reviewed alternative markers based on liquid biopsy and focused on the most promising biomarkers to modify clinical practice, including non-tumoral blood cell count such as absolute neutrophil counts, platelet to lymphocyte ratio, neutrophil to lymphocyte ratio, and derived neutrophil to lymphocyte ratio. We also discussed soluble-derived immune checkpoint-related products such as sPD-L1, circulating tumor cells (detection, count, and marker expression), and circulating tumor DNA-related products. Finally, we explored perspectives for liquid biopsies in the immune landscape and discussed how they could be implemented into lung cancer management with a potential biological-driven decision.

Liquid Biopsy in Lung Cancer: Biomarkers for the Management of Recurrence and Metastasis

Liquid biopsies have emerged as a promising tool for the detection of metastases as well as local and regional recurrence in lung cancer. Liquid biopsy tests involve analyzing a patient's blood, urine, or other body fluids for the detection of biomarkers, including circulating tumor cells or tumor-derived DNA/RNA that have been shed into the bloodstream. Studies have shown that liquid biopsies can detect lung cancer metastases with high accuracy and sensitivity, even before they are visible on imaging scans. Such tests are valuable for early intervention and personalized treatment, aiming to improve patient outcomes. Liquid biopsies are also minimally invasive compared to traditional tissue biopsies, which require the removal of a sample of the tumor for further analysis. This makes liquid biopsies a more convenient and less risky option for patients, particularly those who are not good candidates for invasive procedures due to other medical conditions. While liquid biopsies for lung cancer metastases and relapse are still being developed and validated, they hold great promise for improving the detection and treatment of this deadly disease. Herein, we summarize available and novel approaches to liquid biopsy tests for lung cancer metastases and recurrence detection and describe their applications in clinical practice.

Sequence-Based Platforms for Discovering Biomarkers in Liquid Biopsy of Non-Small-Cell Lung Cancer

Lung cancer detection and monitoring are hampered by a lack of sensitive biomarkers, which results in diagnosis at late stages and difficulty in tracking response to treatment. Recent developments have established liquid biopsies as promising non-invasive methods for detecting biomarkers in lung cancer patients. With concurrent advances in high-throughput sequencing technologies and bioinformatics tools, new approaches for biomarker discovery have emerged. In this article, we survey established and emerging biomarker discovery methods using nucleic acid materials derived from bodily fluids in the context of lung cancer. We introduce nucleic acid biomarkers extracted from liquid biopsies and outline biological sources and methods of isolation. We discuss next-generation sequencing (NGS) platforms commonly used to identify novel biomarkers and describe how these have been applied to liquid biopsy. We highlight emerging biomarker discovery methods, including applications of long-read sequencing, fragmentomics, whole-genome amplification methods for single-cell analysis, and whole-genome methylation assays. Finally, we discuss advanced bioinformatics tools, describing methods for processing NGS data, as well as recently developed software tailored for liquid biopsy biomarker detection, which holds promise for early diagnosis of lung cancer.

Endovascular image-guided sampling of tumor-draining veins provides an enriched source of oncological biomarkers

Introduction

Circulating tumor-derived biomarkers can potentially impact cancer management throughout the continuum of care. This small exploratory study aimed to assess the relative levels of such biomarkers in the tumor-draining vascular beds in patients with solid tumors compared to levels in their peripheral veins.

Methods

Using an endovascular image-guided approach, we obtained blood samples from peripheral veins and other vascular compartments–including the most proximal venous drainage from solid tumors–from a set of nine oncology patients with various primary and metastatic malignancies. We then interrogated these samples for a panel of oncological biomarkers, including circulating tumor cells (CTCs), exosome-derived microRNAs (miRNAs), circulating tumor DNA (ctDNA) mutations, and certain cancer-related proteins/biochemical markers.

Results

We found substantially higher levels of CTCs, certain miRNAs, and specific ctDNA mutations in samples from vascular beds closer to the tumor compared with those from peripheral veins and also noted that some of these signals were altered by treatment procedures.

Discussion

Our results indicate that tumor-proximal venous samples are highly enriched for some oncological biomarkers and may allow for more robust molecular analysis than peripheral vein samples.

Diagnostic value of liquid biopsy in the era of precision medicine: 10 years of clinical evidence in cancer

Liquid biopsy is a diagnostic repeatable test, which in last years has emerged as a powerful tool for profiling cancer genomes in real-time with minimal invasiveness and tailoring oncological decision-making. It analyzes different blood-circulating biomarkers and circulating tumor DNA (ctDNA) is the preferred one. Nevertheless, tissue biopsy remains the gold standard for molecular evaluation of solid tumors whereas liquid biopsy is a complementary tool in many different clinical settings, such as treatment selection, monitoring treatment response, cancer clonal evolution, prognostic evaluation, as well as the detection of early disease and minimal residual disease (MRD). A wide number of technologies have been developed with the aim of increasing their sensitivity and specificity with acceptable costs. Moreover, several preclinical and clinical studies have been conducted to better understand liquid biopsy clinical utility. Anyway, several issues are still a limitation of its use such as false positive and negative results, results interpretation, and standardization of the panel tests. Although there has been rapid development of the research in these fields and recent advances in the clinical setting, many clinical trials and studies are still needed to make liquid biopsy an instrument of clinical routine. This review provides an overview of the current and future clinical applications and opening questions of liquid biopsy in different oncological settings, with particular attention to ctDNA liquid biopsy.

CtDNA's prognostic value in patients with early-stage colorectal cancer after surgery: A meta-analysis and systematic review

BACKGROUND

Circulating tumor DNA (ctDNA) positivity has been shown to suggest the presence of minimally residual tumor cells in numerous investigations. We aimed to assess the prognostic value of ctDNA positivity for recurrence-free survival in patients with early-stage colorectal cancer after radical surgery and following adjuvant chemotherapy.

METHODS

We systematically reviewed studies published in English until August 15, 2022, concerning ctDNA and tumor-node-metastasis I to III colorectal cancer after surgery, and quantified the correlation between ctDNA positivity and early-stage (tumor-node-metastasis stage I-III) colorectal cancer using meta-analysis methods.

RESULTS

In total, the meta-analysis comprised 1713 patients from 6 studies. Patients with ctDNA-positive colorectal cancer after surgery had a significantly higher risk of recurrence than patients with ctDNA-negative colorectal cancer (hazard ratio 4.64, 95% confidence interval 2.17-9.92, z = 3.96; P < .001). After adjuvant chemotherapy, patients who were ctDNA-positive had a significantly higher risk of recurrence than those who were ctDNA-negative (hazard ratio 7.27, 95% confidence interval 4.50-11.75, z = 8.1; P < .001).

CONCLUSIONS

CtDNA positivity may potentially be a predictor for early-stage colorectal tumor recurrence following surgery and adjuvant chemotherapy.

Neoadjuvant sintilimab and chemotherapy in patients with potentially resectable esophageal squamous cell carcinoma (KEEP-G 03): an open-label, single-arm, phase 2 trial

BACKGROUND

The standard neoadjuvant treatments in patients with esophageal squamous cell carcinoma (ESCC) still have either poor safety or efficacy. Better therapies are needed in China.

METHODS

This was an open-label, single-arm, phase 2 trial. Patients with potentially resectable ESCC (cT1b-3, Nany, M0 or T4a, N0-1, or M0) received preoperative intravenous sintilimab plus triplet chemotherapy (liposomal paclitaxel, cisplatin, and S-1) every 3 weeks for two cycles. The primary endpoints were safety and surgical feasibility; the secondary endpoint was major pathological response (MPR) rate. Genomic biomarkers (genetic mutations, tumor mutational burden (TMB), circulating tumor DNA status and immune microenvironment) in baseline tumor samples were investigated.

RESULTS

All 30 patients completed two cycles of neoadjuvant treatment and underwent surgical resection. Grade 3-4 treatment-related adverse events (TRAEs) occurred in 36.7% (11/30) of patients. The most frequent TRAEs were decreased white cell count (76.7%), anemia (76.7%), and decreased neutrophil count (73.3%). All TRAEs were hematological toxicities; none caused ≥30 days surgical delay. The MPR and pathological complete response (pCR) rates were 50.0% (15/30; 95% CI 33.2 to 66.9) and 20.0% (6/30; 95% CI 9.5 to 37.3), respectively. Patients with higher TMB and more clonal mutations were more likely to respond. ERBB2 alterations and ctDNA high-releaser status have a negative correlation with neoadjuvant ICI response. No significant difference was observed between therapeutic response and tumor immune microenvironment.

CONCLUSIONS

Neoadjuvant sintilimab plus platinum-based triplet chemotherapy appeared safe and feasible, did not delay surgery and induced a pCR rate of 20.0% in patients with potentially resectable ESCC.

TRIAL REGISTRATION NUMBER

NCT03946969.

Framework for Adoption of Next-Generation Sequencing (NGS) Globally in the Oncology Area

Radical new possibilities of improved treatment of cancer are on offer from an advanced medical technology already demonstrating its significance: next-generation sequencing (NGS). This refined testing provides unprecedentedly precise diagnoses and permits the use of focused and highly personalized treatments. However, across regions globally, many cancer patients will continue to be denied the benefits of NGS as long as some of the yawning gaps in its implementation remain unattended. The challenges at the regional and national levels are linked because putting the solutions into effect is highly dependent on cooperation between regional- and national-level cooperation, which could be hindered by shortfalls in interpretation or understanding. The aim of the paper was to define and explore the necessary conditions for NGS and make recommendations for effective implementation based on extensive exchanges with policy makers and stakeholders. As a result, the European Alliance for Personalised Medicine (EAPM) developed a maturity framework structured around demand-side and supply-side issues to enable interested stakeholders in different countries to self-evaluate according to a common matrix. A questionnaire was designed to identify the current status of NGS implementation, and it was submitted to different experts in different institutions globally. This revealed significant variability in the different aspects of NGS uptake. Within different regions globally, to ensure those conditions are right, this can be improved by linking efforts made at the national level, where patients have needs and where care is delivered, and at the global level, where major policy initiatives in the health field are underway or in preparation, many of which offer direct or indirect pathways for building those conditions. In addition, in a period when consensus is still incomplete and catching up is needed at a political level to ensure rational allocation of resources-even within individual countries-to enable the best ways to make the necessary provisions for NGS, a key recommendation is to examine where closer links between national and regional actions could complement, support, and mutually reinforce efforts to improve the situation for patients.

Circulating Tumor DNA, Imaging, and Carcinoembryonic Antigen: Comparison of Surveillance Strategies Among Patients Who Underwent Resection of Colorectal Cancer-A Systematic Review and Meta-analysis

BACKGROUND

Almost one-third of colorectal cancer (CRC) patients experience recurrence after resection; nevertheless, follow-up strategies remain controversial. We sought to systematically assess and compare the accuracy of carcinoembryonic antigen (CEA), imaging [positron emission tomography (PET) and computed tomography (CT) scans], and circulating tumor DNA (CtDNA) as surveillance strategies.

PATIENTS AND METHODS

PubMed, Medline, Embase, Scopus, Cochrane, Web of Science, and CINAHL were systematically searched. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was used to assess methodological quality. We performed a bivariate random-effects meta-analysis and reported pooled sensitivity, specificity, and diagnostic odds ratio (DOR) values for each surveillance strategy.

RESULTS

Thirty studies were included in the analysis. PET scans had the highest sensitivity to detect recurrence (0.95; 95%CI 0.91-0.97), followed by CT scans (0.77; 95%CI 0.67-0.85). CtDNA positivity had the highest specificity to detect recurrence (0.95; 95%CI 0.91-0.97), followed by increased CEA levels (0.88; 95%CI 0.82-0.92). Furthermore, PET scans had the highest DOR to detect recurrence (DOR 120.7; 95%CI 48.9-297.9) followed by CtDNA (DOR 37.6; 95%CI 20.8-68.0).

CONCLUSION

PET scans had the highest sensitivity and DOR to detect recurrence, while CtDNA had the highest specificity and second highest DOR. Combinations of traditional cross-sectional/functional imaging and newer platforms such as CtDNA may result in optimized surveillance of patients following resection of CRC.

Emerging Biomarkers in Immune Oncology to Guide Lung Cancer Management

Over the last decade, the use of targeted therapies and immune therapies led to drastic changes in the management lung cancer and translated to improved survival outcomes. This growing arsenal of therapies available for the management of non-small cell lung cancer added more complexity to treatment decisions. The genomic profiling of tumors and the molecular characterization of the tumor microenvironment gradually became essential steps in exploring and identifying markers that can enhance patient selection to facilitate treatment personalization and narrow down therapy options. The advent of innovative diagnostic platforms, such as next-generation sequencing and plasma genotyping (also known as liquid biopsies), has aided in this quest. Currently, programmed cell death ligand 1 expression remains the most recognized and fully validated predictive biomarker of response to immune checkpoint inhibitors. Other markers such as tumor mutational burden, tumor infiltrating lymphocytes, driver mutations, and other molecular elements of the tumor microenvironment bear the potential to be predictive tools; however, the majority are still investigational. In this review, we describe the advances noted thus far on currently validated as well as novel emerging biomarkers that have the potential to guide the use of immunotherapy agents in the management of non-small cell lung cancer.

Simultaneous extraction and quantification of circulating mitochondrial and nuclear DNA using a single plasma sample to predict specific molecular diagnostic implications

The magnitude of variations in the level of circulating mitochondrial (cir-mtDNA) and nuclear DNA (cir-ncDNA) in different diseases has indicated the need for investigating a discriminative approach for evaluating their diagnostic significance. This study reports a typical in-house process for extracting both types of cir-DNAs from a single plasma sample and assessed their usefulness in discriminating type 2 diabetes mellitus patients from healthy individuals to eliminate the prevailing dispute about their discriminative role and improve their diagnostic value. This approach offers a more precise and valuable tool for distinguishing the impact of cir-mtDNA from cir-ncDNA in diagnostic implications.

The Role of Cell-Free DNA in Cancer Treatment Decision Making

The aim of this review is to evaluate the present status of the use of cell-free DNA and its fraction of circulating tumor DNA (ctDNA) because this year July 2022, an ESMO guideline was published regarding the application of ctDNA in patient care. This review is for clinical oncologists to explain the concept, the terms used, the pros and cons of ctDNA; thus, the technical aspects of the different platforms are not reviewed in detail, but we try to help in navigating the current knowledge in liquid biopsy. Since the validated and adequately sensitive ctDNA assays have utility in identifying actionable mutations to direct targeted therapy, ctDNA may be used for this soon in routine clinical practice and in other different areas as well. The cfDNA fragments can be obtained by liquid biopsy and can be used for diagnosis, prognosis, and selecting among treatment options in cancer patients. A great proportion of cfDNA comes from normal cells of the body or from food uptake. Only a small part (<1%) of it is related to tumors, originating from primary tumors, metastatic sites, or circulating tumor cells (CTCs). Soon the data obtained from ctDNA may routinely be used for finding minimal residual disease, detecting relapse, and determining the sites of metastases. It might also be used for deciding appropriate therapy, and/or emerging resistance to the therapy and the data analysis of ctDNA may be combined with imaging or other markers. However, to achieve this goal, further clinical validations are inevitable. As a result, clinicians should be aware of the limitations of the assays. Of course, several open questions are still under research and because of it cfDNA and ctDNA testing are not part of routine care yet.

Cell-Free DNA Fragmentomics: A Promising Biomarker for Diagnosis, Prognosis and Prediction of Response in Breast Cancer

Identifying novel circulating biomarkers predictive of response and informative about the mechanisms of resistance, is the new challenge for breast cancer (BC) management. The integration of omics information will gradually revolutionize the clinical approach. Liquid biopsy is being incorporated into the diagnostic and decision-making process for the treatment of BC, in particular with the analysis of circulating tumor DNA, although with some relevant limitations, including costs. Circulating cell-free DNA (cfDNA) fragmentomics and its integrity index may become a cheaper, noninvasive biomarker that could provide significant additional information for monitoring response to systemic treatments in BC. The purpose of our review is to focus on the available research on cfDNA integrity and its features as a biomarker of diagnosis, prognosis and response to treatments in BC, highlighting new perspectives and critical issues for future applications.