Liquid Biopsies Using Circulating Tumor DNA in Non-Small Cell Lung Cancer

Plasma DNA methylation detection for early screening, diagnosis, and monitoring of esophageal adenocarcinoma and squamous cell carcinoma

BACKGROUND

The early diagnosis rate of esophageal cancer (EC), one of the most prevalent digestive tract cancers worldwide, remains low.

AIM

To investigate the utility of plasma SHOX2, SEPTIN9, EPO, and RNF180 methylation in the clinical diagnosis and monitoring of EC.

METHODS

Plasma samples were collected from 210 patients at Hubei Cancer Hospital, and TaqMan polymerase chain reaction was employed to detect plasma SHOX2, SEPTIN9, RNF180, and EPO methylation. The area under the curve was used to estimate their diagnostic value for EC. Cox and logistic regression analyses were used to estimate the independent screening risk factors for patients with EC.

RESULTS

The sensitivity and specificity of combined assessment of plasma SHOX2, SEPTIN9, RNF180, and EPO methylation for adenocarcinoma, squamous cell carcinoma (SCC), and EC detection were 66.67% and 86.27%, 77.40% and 85.29%, and 76.19% and 86.27%, respectively; the area under the curve values for diagnosing adenocarcinoma, SCC, and EC were 0.737 [95% confidence interval (CI): 0.584–0.89], 0.824 (95%CI: 0.775–0.891), and 0.864 (95%CI: 0.809–0.92), respectively.

CONCLUSION

According to our findings, plasma SHOX2, SEPTIN9, RNF180, and EPO methylation exhibits appreciated sensitivity for diagnosing EC. The precise measurement of plasma SHOX2, SEPTIN9, RNF180, and EPO methylation can improve EC diagnosis and therapy efficacy monitoring.

Discrepancy Between Liquid Biopsy and Tumor Next-Generation Sequencing Due to Low Tumor Fraction in a Patient With Lung Adenocarcinoma

Tumor next-generation sequencing (NGS) is the gold standard molecular testing for driver genomic alterations in patients with advanced non-small cell lung cancer (NSCLC). However, it requires a biopsy, which is an invasive procedure. In contrast, a liquid biopsy is a minimally invasive test that measures circulating tumor DNA (ctDNA) in the plasma and can be also used for molecular profiling. We report a case of a patient with stage IV metastatic lung adenocarcinoma with a negative liquid biopsy for tumor-derived genomic alterations but positive tissue NGS for mutations, including a driver KRASG12C mutation. The discrepancy between the two results can be attributed to low levels of ctDNA determined by tumor fraction below 1%, which prevents the liquid biopsy assay from detecting genomic alterations when the tumor shedding into the blood is below the detection threshold. It is well known in the literature that false negative liquid biopsies are possible, but a significant finding this case highlights is the clinical importance of tumor fraction in a liquid biopsy report. We conclude that patients with a liquid biopsy with low tumor fraction need further testing with tumor NGS to determine the presence of driver genomic alterations.

ctDNA for the Evaluation and Management of EGFR-Mutant Non-Small Cell Lung Cancer

Circulating tumor DNA (ctDNA) offers a new paradigm in optimizing treatment strategies for epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC). Its potential spans early-stage disease, influencing adjuvant therapy, to advanced disease, where it aids in identifying genomic markers and resistance mechanisms. This review explores the evolving landscape of utilizing liquid biopsies, specifically circulating tumor DNA (ctDNA), in the management of NSCLC with EGFR mutations. While tissue-based genomic testing remains the cornerstone for clinical decision-making, liquid biopsies offer a well-validated, guideline-recommended alternative approach. Ongoing trials integrating ctDNA for EGFR-mutant NSCLC management are also discussed, shedding light on the potential of ctDNA in early-stage disease, including its applications in prognostication, risk stratification, and minimal residual disease detection post-curative intent treatment. For advanced disease, the role of ctDNA in identifying resistance mechanisms to EGFR tyrosine kinase inhibitors (TKIs) is explored, providing insights into disease progression and guiding treatment decisions. This review also addresses the challenges, including the limitations in sensitivity of current assays for disease recurrence detection, and calls for future studies to refine treatment approaches, standardize reporting, and explore alternative biofluids for enhanced sensitivity. A systematic approach is crucial to address barriers to ctDNA deployment, ensuring equitable access, and facilitating its integration into routine clinical practice.

Saliva as a potential non-invasive liquid biopsy for early and easy diagnosis/prognosis of head and neck cancer

Head and neck squamous cell carcinomas (HNSCCs) are the most devastating diseases in India and southeast Asia. It is a preventable and curable disease if detected early. Tobacco and alcohol consumption are the two major risk-factors but infection of high-risk HPVs are also associated with development of predominantly oral and oropharyngeal carcinomas. Interestingly, unlike cervical cancer, HPV-induced HNSCCs show good prognosis and better survival in contrast, majority of tobacco-associated HPV-ve HNSCCs are highly aggressive with poor clinical outcome. Biomarker analysis in circulatory body-fluids for early cancer diagnosis, prognosis and treatment monitoring are becoming important in clinical practice. Early diagnosis using non-invasive saliva for oral or other diseases plays an important role in successful treatment and better prognosis. Saliva mirrors the body's state of health as it comes into direct contact with oral lesions and needs no trained manpower to collect, making it a suitable bio-fluid of choice for screening. Saliva can be used to detect not only virus, bacteria and other biomarkers but variety of molecular and genetic markers for an early detection, treatment and monitoring cancer and other diseases. The performance of saliva-based diagnostics are reported to be highly (≥95 %) sensitive and specific indicating the test's ability to correctly identify true positive or negative cases. This review focuses on the potentials of saliva in the early detection of not only HPV or other pathogens but also identification of highly reliable gene mutations, oral-microbiomes, metabolites, salivary cytokines, non-coding RNAs and exosomal miRNAs. It also discusses the importance of saliva as a reliable, cost-effective and an easy alternative to invasive procedures.

Role of radiation in oligometastases and oligoprogression in metastatic non-small cell lung cancer: consensus and controversy

INTRODUCTION

The oligometastatic state in non-small cell lung cancer (NSCLC) has recently become well-established. However, the specific definition of oligometastases remains unclear. Several smaller randomized studies have investigated the safety and efficacy of radiation as metastasis-directed therapy (MDT) in oligometastatic NSCLC, which have led the way to larger studies currently accruing patients globally.

AREAS COVERED

This review covers the definitions of 'oligometastases' and explains why the oligometastatic state is becoming increasingly relevant in metastatic NSCLC. This includes the rationale for MDT in oligometastatic NSCLC, specifically reviewing stereotactic body radiation therapy (SBRT) as a treatment strategy. This review details many randomized trials that support radiation as MDT and introduces trials that are currently accruing patients. Finally, it explores some of the controversies that warrant further investigation.

EXPERT OPINION

Radiation treatment, specifically SBRT, has been shown to be safe, convenient, and cost-effective as MDT. As systemic therapy, including targeted agents and immunotherapy, continues to improve, the precise role(s) and timing of radiation therapy may evolve. However, radiation therapy as MDT will continue to be an integral part of treatment in patients with oligometastatic NSCLC.

Genomic approaches to cancer and minimal residual disease detection using circulating tumor DNA

Liquid biopsies using cell-free circulating tumor DNA (ctDNA) are being used frequently in both research and clinical settings. ctDNA can be used to identify actionable mutations to personalize systemic therapy, detect post-treatment minimal residual disease (MRD), and predict responses to immunotherapy. ctDNA can also be isolated from a range of different biofluids, with the possibility of detecting locoregional MRD with increased sensitivity if sampling more proximally than blood plasma. However, ctDNA detection remains challenging in early-stage and post-treatment MRD settings where ctDNA levels are minuscule giving a high risk for false negative results, which is balanced with the risk of false positive results from clonal hematopoiesis. To address these challenges, researchers have developed ever-more elegant approaches to lower the limit of detection (LOD) of ctDNA assays toward the part-per-million range and boost assay sensitivity and specificity by reducing sources of low-level technical and biological noise, and by harnessing specific genomic and epigenomic features of ctDNA. In this review, we highlight a range of modern assays for ctDNA analysis, including advancements made to improve the signal-to-noise ratio. We further highlight the challenge of detecting ultra-rare tumor-associated variants, overcoming which will improve the sensitivity of post-treatment MRD detection and open a new frontier of personalized adjuvant treatment decision-making.

Atezolizumab and stereotactic body radiotherapy in patients with advanced non-small cell lung cancer: safety, clinical activity and ctDNA responses-the ComIT-1 trial

The introduction of immune checkpoint inhibitors has transformed the treatment landscape of metastatic non-small cell lung cancer. However, challenges remain to increase the fraction of patients achieving durable clinical responses to these drugs and to help monitor the treatment effect. In this phase II trial, we investigated the toxicity, systemic responses and circulating tumour DNA responses in patients (n = 21) with advanced non-small-cell lung cancer treated with atezolizumab and stereotactic body radiotherapy in the second or later line. We found the combined treatment to be safe with grade 3 toxicity reported in three patients. As the best overall response, four patients had a partial response, eight had stable disease and five had progressive disease. Median overall survival time was still not reached after a median follow-up of 26.5 months and 10/15 patients with programmed death-ligand 1 negative tumours were alive >18 months after the start of the study treatment. ctDNA was detectable at baseline in 11 patients. A rapid decline in ctDNA to <30% of baseline levels was seen in three patients, two of which were radiographic responders and one was considered clinically benefiting from therapy for almost 1 year.

Liquid Biopsies in Lung Cancer

As lung cancer has the highest cancer-specific mortality rates worldwide, there is an urgent need for new therapeutic and diagnostic approaches to detect early-stage tumors and to monitor their response to the therapy. In addition to the well-established tissue biopsy analysis, liquid-biopsy-based assays may evolve as an important diagnostic tool. The analysis of circulating tumor DNA (ctDNA) is the most established method, followed by other methods such as the analysis of circulating tumor cells (CTCs), microRNAs (miRNAs), and extracellular vesicles (EVs). Both PCR- and NGS-based assays are used for the mutational assessment of lung cancer, including the most frequent driver mutations. However, ctDNA analysis might also play a role in monitoring the efficacy of immunotherapy and its recent accomplishments in the landscape of state-of-the-art lung cancer therapy. Despite the promising aspects of liquid-biopsy-based assays, there are some limitations regarding their sensitivity (risk of false-negative results) and specificity (interpretation of false-positive results). Hence, further studies are needed to evaluate the usefulness of liquid biopsies for lung cancer. Liquid-biopsy-based assays might be integrated into the diagnostic guidelines for lung cancer as a tool to complement conventional tissue sampling.

Minimal Residual Disease Monitoring in Radically Treated Non-Small Cell Lung Cancer: Challenges and Future Directions

Circulating tumor DNA (ctDNA) analysis can identify patients with residual disease before it is clinically or radiologically evident. Minimal residual disease (MRD) is an advancing area in the management of radically treated solid tumors. Which MRD assay is optimum and when it should be used is still not defined. Whilst promising, the clinical utility of this technology to guide patient care is still investigational in non-small cell lung cancer (NSCLC) and has not entered routine care. Once technically and clinically optimized, MRD may be utilized to personalize adjuvant therapy, detect disease relapse earlier and improve cure rates. In this review, we discuss the current status of MRD monitoring in NSCLC by summarizing frequently used MRD assays and their associated evidence in NSCLC. We discuss the potential applications of these technologies and the challenge of demonstrating MRD clinical utility in trials.

Aneuploid subtypes of circulating tumor cells and circulating tumor-derived endothelial cells predict the overall survival of advanced lung cancer

Objective

This study aimed to detect circulating tumor cells (CTCs) and circulating tumor-derived endothelial cells (CTECs) in patients with advanced lung cancer, for describing the distribution characteristics of CTC and CTEC subtypes, exploring the correlation between CTC/CTEC subtypes and novel prognostic biomarkers.

Methods

A total of 52 patients with advanced lung cancer were enrolled in this study. Using the subtraction enrichment-immunofluorescence in situ hybridization (SE-iFISH) system, CTCs and CTECs derived from these patients were identified.

Results

Based on cell size, there were 49.3% small and 50.7% large CTCs, and 23.0% small and 77.0% large CTECs. Triploidy, tetraploidy, and multiploidy varied in the small and large CTCs/CTECs. Besides these three aneuploid subtypes, monoploidy was found in the small and large CTECs. Triploid and multiploid small CTCs and tetraploid large CTCs were associated with shorter overall survival (OS) in patients with advanced lung cancer. However, none of the CTECs subtypes showed a significant correlation with patient prognosis. In addition, we found strong positive correlations (P<0.0001) in the four groups including triploid small cell size CTCs and multiploid small cell size CTECs, and multiploid small cell size CTCs and monoploid small cell size CTECs. Furthermore, combined detection of the specific subtypes, including triploid small CTC and monoploid small CTEC, triploid small CTC and triploid small CTEC, and multiploid small CTC and monoploid small CTEC, were associated with poor prognosis in advanced lung cancer.

Conclusions

Aneuploid small CTCs are associated with the outcome of patients with advanced lung cancer. In particular, the combined detection of triploid small CTCs and monoploid small CTECs, triploid small CTCs and triploid small CTECs, and multiploid small CTCs and monoploid small CTECs has clinical significance for predicting prognosis in patients with advanced lung cancer.

Making the Rounds: Exploring the Role of Circulating Tumor DNA (ctDNA) in Non-Small Cell Lung Cancer

Advancements in the clinical practice of non-small cell lung cancer (NSCLC) are shifting treatment paradigms towards increasingly personalized approaches. Liquid biopsies using various circulating analytes provide minimally invasive methods of sampling the molecular content within tumor cells. Plasma-derived circulating tumor DNA (ctDNA), the tumor-derived component of cell-free DNA (cfDNA), is the most extensively studied analyte and has a growing list of applications in the clinical management of NSCLC. As an alternative to tumor genotyping, the assessment of oncogenic driver alterations by ctDNA has become an accepted companion diagnostic via both single-gene polymerase chain reactions (PCR) and next-generation sequencing (NGS) for advanced NSCLC. ctDNA technologies have also shown the ability to detect the emerging mechanisms of acquired resistance that evolve after targeted therapy. Furthermore, the detection of minimal residual disease (MRD) by ctDNA for patients with NSCLC after curative-intent treatment may serve as a prognostic and potentially predictive biomarker for recurrence and response to therapy, respectively. Finally, ctDNA analysis via mutational, methylation, and/or fragmentation multi-omic profiling offers the potential for improving early lung cancer detection. In this review, we discuss the role of ctDNA in each of these capacities, namely, for molecular profiling, treatment response monitoring, MRD detection, and early cancer detection of NSCLC.

Liquid Biopsy and Circulating Biomarkers for the Diagnosis of Precancerous and Cancerous Oral Lesions

Oral cancer is one of the most common malignancies worldwide, accounting for 2% of all cases annually and 1.8% of all cancer deaths. To date, tissue biopsy and histopathological analyses are the gold standard methods for the diagnosis of oral cancers. However, oral cancer is generally diagnosed at advanced stages with a consequent poor 5-year survival (~50%) due to limited screening programs and inefficient physical examination strategies. To address these limitations, liquid biopsy is recently emerging as a novel minimally invasive tool for the early identification of tumors as well as for the evaluation of tumor heterogeneity and prognosis of patients. Several studies have demonstrated that liquid biopsy in oral cancer could be useful for the detection of circulating biomarkers including circulating tumor DNA (ctDNA), microRNAs (miRNAs), proteins, and exosomes, thus improving diagnostic strategies and paving the way to personalized medicine. However, the application of liquid biopsy in oral cancer is still limited and further studies are needed to better clarify its clinical impact. The present manuscript aims to provide an updated overview of the potential use of liquid biopsy as an additional tool for the management of oral lesions by describing the available methodologies and the most promising biomarkers.

Prognostic potential of circulating tumor DNA detection at different time periods in resectable non-small cell lung cancer: Evidence from a meta-analysis

This study was undertaken to evaluate the prognostic significance of circulating tumour DNA (ctDNA) detection at different time periods in resectable non-small cell lung cancer (NSCLC). A comprehensive search strategy was conducted through the electronic platforms published up to June 2022. In total, 7 studies with 1138 patients were included. Patients with positive ctDNA have an increased risk of recurrence and mortality. The association between risk of recurrence and detectable ctDNA after surgery 3 days-2 weeks and 1-3 months was stronger than detected at 1 week before surgery. The predictive value of longitudinal detection ctDNA for recurrence and mortality was not stronger than at other time periods. In conclusion, ctDNA is a promising biomarker for predictive recurrence and survival in resectable NSCLC patients. The ctDNA detection after surgery 3 days-2 weeks with more reliably and feasible in identifying resectable NSCLC patients at high risk for recurrence.

Comparison of the somatic mutations between circulating tumor DNA and tissue DNA in Chinese patients with non-small cell lung cancer

BACKGROUND

Non-invasive liquid biopsies of circulating tumor DNA (ctDNA) is a rapidly growing field in the research of non-small cell lung cancer (NSCLC). In this study, factors affecting the concordance of mutations in paired plasma and tissue and the detection rate of ctDNA in real-world Chinese patients with NSCLC were identified.

METHODS

Peripheral blood and paired formalin-fixed paraffin-embedded tumor tissue samples from 125 NSCLC patients were collected and analyzed by sequencing 15 genes. Serological biomarkers were tested by immunoassay.

RESULTS

The overall concordance between tumor and plasma samples and the detection rate of somatic mutations in ctDNA was 69.2% and 78.4%, respectively. The concordance and detection rate raised with clinical stage were stage I: 14.3%, 14.3%; stage II: 53.3%, 60.0%; stage III: 71.4%, 78.1%; stage IV: 74.1%, 85.2%. With increased tumor diameter, the concordance and detection rate raised from 33.33% to 71.64% and 33.33% to 80.8%, respectively. For patients with partial response, stable disease, progressive disease, and who were treatment-naïve, the concordance and detection rates were 0.0%, 62.7%, 75.2, 73.6%, and 16.7%, 61.9%, 83.3%, 86.5%, respectively. Serological markers: CEA, CA125, NSE, and CYFRA21-1 were significantly higher for patients with detectable somatic alterations in ctDNA than in those who were ctDNA negative (17.08 ng/mL vs. 3.95 ng/mL, 21.63 U/mL vs. 18.27 U/mL, 17.68 U/mL vs. 14.14 U/mL, and 6.55 U/mL vs. 3.81 U/mL, respectively).

CONCLUSION

Advanced-stage, treatment naïve or poor therapy outcome, and large tumor size were associated with a high concordance and detection rate. Patients with detectable mutations in ctDNA had a higher level of carcinoembryonic antigen, CA125, NSE, and CYFRA21-1.

Circulating Tumor DNA Minimal Residual Disease Detection of Non-Small-Cell Lung Cancer Treated With Curative Intent

Circulating tumor DNA (ctDNA) minimal residual disease (MRD) is a powerful biomarker with the potential to improve survival outcomes for non-small-cell lung cancer (NSCLC). Multiple groups have shown the ability to detect MRD following curative-intent NSCLC treatment using next-generation sequencing-based assays of plasma cell-free DNA. These studies have been modest in size, largely retrospective, and without thorough prospective clinical validation. Still, when restricting measurement to the first post-treatment timepoint to assess the clinical performance of ctDNA MRD detection, they have demonstrated sensitivity for predicting disease relapse ranging between 36% and 100%, and specificity ranging between 71% and 100%. When considering all post-treatment follow-up timepoints (surveillance), including those beyond the initial post-treatment measurement, these assays' performances improve with sensitivity and specificity for identifying relapse ranging from 82% to 100% and 70% to 100%, respectively. In this manuscript, we review the evidence available to date regarding ctDNA MRD detection in patients with NSCLC undergoing curative-intent treatment and the ongoing prospective studies involving ctDNA MRD detection in this patient population.

Case Report: Durable Clinical Response to Third-Line Pyrotinib After Resistance to Trastuzumab in a Gastric Cancer Patient

Background

Trastuzumab plus chemotherapy remains the standard first-line treatment strategy for HER2-positive gastric cancer (GC). Trastuzumab resistance, on the other hand, remains a significant issue. There are a few effective anti-HER2 agents for patients who develop resistance to trastuzumab.

Case Presentation

A 49-year-old female was diagnosed with stage IV GC with liver and lung metastasis in July 2017. She underwent gastrostomy, and the immunohistochemistry (IHC) result of postoperative tissue demonstrated HER2 (3+). She received first-line treatment of trastuzumab (440 mg), oxaliplatin (200 mg), and S-1 (40 mg). After treatment for 6 months, the patient achieved complete response (CR) with PFS up to 21 months. After progression, she subsequently received trastuzumab (440 mg) plus oxaliplatin (200 mg) as second-line treatment. However, the patient developed resistance to trastuzumab after 12 months of treatment. She started to receive third-line treatment of irinotecan (200 mg d1) and capecitabine (60 mg bid) plus pyrotinib (400 mg/day). After 2 months of treatment, the tumor is evaluated as partial response with PFS of 12 months.

Conclusions

We presented a patient with HER2-positive GC who benefited from the pyrotinib-based treatment after two lines of trastuzumab-based therapies failed. Further research is required to validate such conclusions.

The Stroma Liquid Biopsy Panel Contains a Stromal-Epithelial Gene Signature Ratio That Is Associated with the Histologic Tumor-Stroma Ratio and Predicts Survival in Colon Cancer

Liquid biopsy has emerged as a novel approach to tumor characterization, offering advantages in sample accessibility and tissue heterogeneity. However, as mutational analysis predominates, the tumor microenvironment has largely remained unacknowledged in liquid biopsy research. The current work provides an explorative transcriptomic characterization of the Stroma Liquid Biopsy^TM (SLB) proteomics panel in colon carcinoma by integrating single-cell and bulk transcriptomics data from publicly available repositories. Expression of SLB genes was significantly enriched in tumors with high histologic stromal content in comparison to tumors with low stromal content (median enrichment score 0.308 vs. 0.222, p = 0.036). In addition, we identified stromal-specific and epithelial-specific expression of the SLB genes, that was subsequently integrated into a gene signature ratio. The stromal-epithelial signature ratio was found to have prognostic significance in a discovery cohort of 359 colon adenocarcinoma patients (OS HR 2.581, 95%CI 1.567-4.251, p < 0.001) and a validation cohort of 229 patients (OS HR 2.590, 95%CI 1.659-4.043, p < 0.001). The framework described here provides transcriptomic evidence for the prognostic significance of the SLB panel constituents in colon carcinoma. Plasma protein levels of the SLB panel may reflect histologic intratumoral stromal content, a poor prognostic tumor characteristic, and hence provide valuable prognostic information in liquid biopsy.

The value of cell-free circulating tumour DNA profiling in advanced non-small cell lung cancer (NSCLC) management

Liquid biopsy (LB) has boosted a remarkable change in the management of cancer patients by contributing to tumour genomic profiling. Plasma circulating cell-free tumour DNA (ctDNA) is the most widely searched tumour-related element for clinical application. Specifically, for patients with lung cancer, LB has revealed valuable to detect the diversity of targetable genomic alterations and to detect and monitor the emergence of resistance mechanisms. Furthermore, its non-invasive nature helps to overcome the difficulty in obtaining tissue samples, offering a comprehensive view about tumour diversity. However, the use of the LB to support diagnostic and therapeutic decisions still needs further clarification. In this sense, this review aims to provide a critical view of the clinical importance of plasma ctDNA analysis, the most widely applied LB, and its limitations while anticipating concepts that will intersect the present and future of LB in non-small cell lung cancer patients.

Graphical Abstract

Can Circulating Cell-Free DNA or Circulating Tumor DNA Be a Promising Marker in Ovarian Cancer?

In recent years, the studies on ovarian cancer have made great progress, but the morbidity and mortality of patients with ovarian cancer are still very high. Due to the lack of effective early screening and detecting tools, 70% of ovarian cancer patients are diagnosed at an advanced stage. The overall survival rate of ovarian cancer patients treated with surgical combined with chemotherapy has not been significantly improved, and they usually relapse or resist chemotherapy. Therefore, a novel tumor marker is beneficial for the diagnosis and prognosis of patients with ovarian cancer. As the index of "liquid biopsy," circulating cell-free DNA/circulating tumor DNA (cfDNA/ctDNA) has attracted a lot of attention. It has more remarkable advantages than traditional methods and gives a wide range of clinical applications in kinds of solid tumors. This review attempts to illuminate the important value of cfDNA/ctDNA in ovarian cancer, including diagnosis, monitoring, and prognosis. Meanwhile, we will present future directions and challenges for detection of cfDNA/ctDNA.