Perioperative ctDNA-based Molecular Residual Disease Detection for Non-Small Cell Lung Cancer: A Prospective Multicenter Cohort Study (LUNGCA-1)

Liquid biopsy: paving a new avenue for cancer research

The current constraints associated with cancer diagnosis and molecular profiling, which rely on invasive tissue biopsies or clinical imaging, have spurred the emergence of the liquid biopsy field. Liquid biopsy involves the extraction of circulating tumor cells (CTCs), circulating free or circulating tumor DNA (cfDNA or ctDNA), circulating cell-free RNA (cfRNA), extracellular vesicles (EVs), and tumor-educated platelets (TEPs) from bodily fluid samples. Subsequently, these components undergo molecular characterization to identify biomarkers that are critical for early cancer detection, prognosis, therapeutic assessment, and post-treatment monitoring. These innovative biosources exhibit characteristics analogous to those of the primary tumor from which they originate or interact. This review comprehensively explores the diverse technologies and methodologies employed for processing these biosources, along with their principal clinical applications.

Checkmate 77T: Perioperative chemoimmunotherapy outperforms in early-stage NSCLC

Approximately 1 in 4 patients with NSCLC present with resectable disease. Although surgery is potentially curative, 30%-50% of patients relapse. Studies have shown that neoadjuvant, adjuvant, and perioperative chemoimmunotherapy improve outcomes. The Checkmate 77T trial explored if perioperative platinum-based chemotherapy plus nivolumab, surgical resection, then adjuvant nivolumab further improved outcomes including EFS.1.

Circulating tumor DNA (ctDNA) application in investigation of cancer: Bench to bedside

Now, genomics forms the core of the precision medicine concept. Comprehensive investigations of tumor genomes have made it possible to characterize tumors at the molecular level and, specifically, to identify the fundamental processes that cause condition. A variety of kinds of tumors have seen better outcomes for patients as a result of the development of novel medicines to tackle these genetic-driving processes. Since therapy may exert selective pressure on cancers, non-invasive methods such as liquid biopsies can provide the opportunity for rich reservoirs of crucial and real-time genetic data. Liquid biopsies depend on the identification of circulating cells from tumors, circulating tumor DNA (ctDNA), RNA, proteins, lipids, and metabolites found in patient biofluids, as well as cell-free DNA (cfDNA), which exists in those with cancer. Although it is theoretically possible to examine biological fluids other than plasma, such as pleural fluid, urine, saliva, stool, cerebrospinal fluid, and ascites, we will limit our discussion to blood and solely cfDNA here for the sake of conciseness. Yet, the pace of wider clinical acceptance has been gradual, partly due to the increased difficulty of choosing the best analysis for the given clinical issue, interpreting the findings, and delaying proof of value from clinical trials. Our goal in this review is to discuss the current clinical value of ctDNA in cancers and how clinical oncology systems might incorporate procedures for ctDNA testing.

Evaluation of molecular residual disease in operable non-small cell lung cancer with gene fusions, MET exon skipping or de novo MET amplification

Gene fusions and MET alterations are rare and difficult to detect in plasma samples. The clinical detection efficacy of molecular residual disease (MRD) based on circulating tumor DNA (ctDNA) in patients with non-small cell lung cancer (NSCLC) with these mutations remains unknown. This prospective, non-intervention study recruited 49 patients with operable NSCLC with actionable gene fusions (ALK, ROS1, RET, and FGFR1), MET exon 14 skipping or de novo MET amplification. We analyzed 43 tumor tissues and 111 serial perioperative plasma samples using 1021- and 338-gene panels, respectively. Detectable MRD correlated with a significantly higher recurrence rate (P < 0.001), yielding positive predictive values of 100% and 90.9%, and negative predictive values of 82.4% and 86.4% at landmark and longitudinal time points, respectively. Patients with detectable MRD showed reduced disease-free survival (DFS) compared to those with undetectable MRD (P < 0.001). Patients who harbored tissue-derived fusion/MET alterations in their MRD had reduced DFS compared to those who did not (P = 0.05). To our knowledge, this is the first comprehensive study on ctDNA-MRD clinical detection efficacy in operable NSCLC patients with gene fusions and MET alterations. Patients with detectable tissue-derived fusion/MET alterations in postoperative MRD had worse clinical outcomes.

Clinical application of ctDNA in early diagnosis, treatment and prognosis of patients with non-small cell lung cancer

Lung cancer is one of the most common malignancies worldwide, with non-small cell lung cancer (NSCLC) being the most common type. As understanding of precise treatment options for NSCLC deepens, circulating tumor DNA (ctDNA) has emerged as a potential biomarker that has become a research hotspot and may represent a new approach for the individualized diagnosis and treatment of NSCLC. This article reviews the applications of ctDNA for the early screening of patients with NSCLC, guiding targeted therapy and immunotherapy, evaluating chemotherapy and postoperative efficacy, assessing prognosis and monitoring recurrence. With the in-depth study of the pathogenesis of NSCLC, plasma ctDNA may become an indispensable part of the precise treatment of NSCLC, which has great clinical application prospects.

Alectinib in Early-Stage Anaplastic Lymphoma Kinase-Positive Non-Small Cell Lung Cancer: Current Evidence and Future Challenges

BACKGROUND

Targeted therapies changed the treatment of advanced oncogene-addicted non-small cell lung cancer and could also improve outcomes in resectable disease.

RESULTS

The ALINA trial evaluated the clinical benefit of adjuvant alectinib compared with standard chemotherapy and met the primary endpoint with a significant increase in disease-free survival at 2 years among anaplastic lymphoma kinase positive patients with stage IB-IIIA disease; two phase II trials (ALNEO and NAUTIKA1) are currently evaluating perioperative treatment with alectinib, and the results of the case reports published to date are encouraging.

CONCLUSION

In resectable anaplastic lymphoma kinase-positive lung cancer, adjuvant alectinib represents the new standard of care and could soon be used in perioperative treatment.

Prognostic implication of methylation-based circulating tumor DNA detection prior to surgery in stage I non-small cell lung cancer

BACKGROUND

Circulating tumor DNA (ctDNA) positivity at diagnosis, which is associated with worse outcomes in multiple solid tumors including stage I-III non-small cell lung cancer (NSCLC), may have utility to guide (neo)adjuvant therapy.

METHODS

In this retrospective study, 260 patients with clinical stage I NSCLC (180 adenocarcinoma, 80 squamous cell carcinoma) were allocated (2:1) to high- and low-risk groups based on relapse versus disease-free status ≤5 years post-surgery. We evaluated the association of preoperative ctDNA detection by a plasma-only targeted methylation-based multi-cancer early detection (MCED) test with NSCLC relapse ≤5 years post-surgery in the overall population, followed by histology-specific subgroup analyses.

RESULTS

Across clinical stage I patients, preoperative ctDNA detection did not associate with relapse within 5 years post-surgery. Sub-analyses confined to lung adenocarcinoma suggested a histology-specific association between ctDNA detection and outcome. In this group, ctDNA positivity tended to associate with relapse within 2 years, suggesting prognostic implications of MCED test positivity may be histology- and time-dependent in stage I NSCLC. Preoperative ctDNA detection was associated with upstaging of clinical stage I to pathological stage II-III NSCLC.

CONCLUSIONS

Our findings suggest preoperative ctDNA detection in patients with resectable clinical stage I NSCLC using MCED, a pan-cancer screening test developed for use in an asymptomatic population, has no detectable prognostic value for relapse ≤5 years post-surgery. MCED detection may be associated with early adenocarcinoma relapse and increased pathological upstaging rates in stage I NSCLC. However, given the exploratory nature of these findings, independent validation is required.

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

OBJECTIVES

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

METHOD

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

RESULTS

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

CONCLUSION

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

The ASCENT Trial: a phase 2 study of induction and consolidation afatinib and chemoradiation with or without surgery in stage III EGFR-mutant NSCLC

BACKGROUND

The role of tyrosine kinase inhibitors (TKIs) in early-stage and metastatic oncogene-driven non-small cell lung cancer (NSCLC) is established, but it remains unknown how best to integrate TKIs with concurrent chemoradiotherapy (cCRT) in locally advanced disease. The phase 2 ASCENT trial assessed the efficacy and safety of afatinib and cCRT with or without surgery in locally advanced epidermal growth factor receptor (EGFR)-mutant NSCLC.

PATIENTS AND METHODS

Adults ≥18 years with histologically confirmed stage III (AJCC 7th edition) NSCLC with activating EGFR mutations were enrolled at Mass General and Dana-Farber/Brigham Cancer Centers, Boston, Massachusetts. Patients received induction afatinib 40 mg daily for 2 months, then cisplatin 75 mg/m2 and pemetrexed 500 mg/m2 IV every 3 weeks during RT (definitive or neoadjuvant dosing). Patients with resectable disease underwent surgery. All patients were offered consolidation afatinib for 2 years. The primary endpoint was the objective response rate (ORR) to induction TKI. Secondary endpoints were safety, conversion to operability, progression-free survival (PFS), and overall survival (OS). Analyses were performed on the intention-to-treat population.

RESULTS

Nineteen patients (median age 56 years; 74% female) were enrolled. ORR to induction afatinib was 63%. Seventeen patients received cCRT; 2/9 previously unresectable became resectable. Ten underwent surgery; 6 had a major or complete pathological response. Thirteen received consolidation afatinib. With a median follow-up of 5.0 years, median PFS and OS were 2.6 (95% CI, 1.4-3.1) and 5.8 years (2.9-NR), respectively. Sixteen recurred or died; 6 recurrences were isolated to CNS. The median time to progression after stopping consolidation TKI was 2.9 months (95% CI, 1.1-7.2). Four developed grade 2 pneumonitis. There were no treatment-related deaths.

CONCLUSION

We explored the efficacy of combining TKI with cCRT in oncogene-driven NSCLC. Induction TKI did not compromise subsequent receipt of multimodality therapy. PFS was promising, but the prevalence of CNS-only recurrences and rapid progression after TKI discontinuation speak to unmet needs in measuring and eradicating micrometastatic disease.

Decoding the Dynamics of Circulating Tumor DNA in Liquid Biopsies

Circulating tumor DNA (ctDNA), a fragment of tumor DNA found in the bloodstream, has emerged as a revolutionary tool in cancer management. This review delves into the biology of ctDNA, examining release mechanisms, including necrosis, apoptosis, and active secretion, all of which offer information about the state and nature of the tumor. Comprehensive DNA profiling has been enabled by methods such as whole genome sequencing and methylation analysis. The low abundance of the ctDNA fraction makes alternative techniques, such as digital PCR and targeted next-generation exome sequencing, more valuable and accurate for mutation profiling and detection. There are numerous clinical applications for ctDNA analysis, including non-invasive liquid biopsies for minimal residual disease monitoring to detect cancer recurrence, personalized medicine by mutation profiling for targeted therapy identification, early cancer detection, and real-time evaluation of therapeutic response. Integrating ctDNA analysis into routine clinical practice creates promising avenues for successful and personalized cancer care, from diagnosis to treatment and follow-up.

Implementing circulating tumor DNA as a prognostic biomarker in resectable non-small cell lung cancer

Systemic treatment of resectable non-small cell lung cancer (NSCLC) is evolving with emerging neoadjuvant, perioperative, and adjuvant immunotherapy approaches. Circulating tumor DNA (ctDNA) detection at clinical diagnosis, during neoadjuvant therapy, or after resection may discern high-risk patients who might benefit from therapy escalation or switch. This Review summarizes translational implications of data supporting ctDNA-based risk determination in NSCLC and outstanding questions regarding ctDNA validity/utility as a prognostic biomarker. We discuss emerging ctDNA capabilities to refine clinical tumor-node-metastasis (TNM) staging in lung adenocarcinoma, ctDNA dynamics during neoadjuvant therapy for identifying patients deriving suboptimal benefit, and postoperative molecular residual disease (MRD) detection to escalate systemic therapy. Considering differential relapse characteristics in landmark MRD-negative/MRD-positive patients, we propose how ctDNA might integrate with pathological response data for optimal postoperative risk stratification.

A Locally Advanced NSCLC Patient Harboring a Rare KIF13A-RET Fusion Benefited from Pralsetinib: A Case Report

The application of adjuvant treatment has significantly enhanced the survival of patients with resectable non-small cell lung cancer (NSCLC) carrying driver gene mutations. However, adjuvant-targeted therapy remains controversial for some NSCLC patients carrying rare gene mutations such as RET, as there is currently a lack of confirmed randomized controlled trials demonstrating efficacy. In this report, we describe the case of a 58-year-old man with stage IIIA NSCLC who underwent complete lobectomy with selective lymph node dissection. Postoperative next-generation sequencing revealed that the patient harbored a rare KIF13A-RET fusion. The patient elected to receive adjuvant treatment with pralsetinib monotherapy and underwent serial circulating tumor DNA (ctDNA) monitoring after surgery. During follow-up, despite experiencing dose reduction and irregular medication adherence, the patient still achieved a satisfactory disease-free survival (DFS) of 27 months. Furthermore, ctDNA predicted tumor recurrence 4 months earlier than imaging techniques. The addition of bevacizumab to the original regimen upon recurrence continued to be beneficial. Pralsetinib demonstrated promising efficacy as adjuvant therapy, while ctDNA analysis offered a valuable tool for early detection of tumor recurrence. By leveraging targeted therapies and innovative monitoring techniques, we aim to improve outcomes and quality of life for NSCLC patients in the future.

Current status of molecular diagnostics for lung cancer

The management of lung cancer (LC) requires the analysis of a diverse spectrum of molecular targets, including kinase activating mutations in EGFR, ERBB2 (HER2), BRAF and MET oncogenes, KRAS G12C substitutions, and ALK, ROS1, RET and NTRK1-3 gene fusions. Administration of immune checkpoint inhibitors (ICIs) is based on the immunohistochemical (IHC) analysis of PD-L1 expression and determination of tumor mutation burden (TMB). Clinical characteristics of the patients, particularly age, gender and smoking history, significantly influence the probability of finding the above targets: for example, LC in young patients is characterized by high frequency of kinase gene rearrangements, while heavy smokers often have KRAS G12C mutations and/or high TMB. Proper selection of first-line therapy influences overall treatment outcomes, therefore, the majority of these tests need to be completed within no more than 10 working days. Activating events in MAPK signaling pathway are mutually exclusive, hence, fast single-gene testing remains an option for some laboratories. RNA next-generation sequencing (NGS) is capable of detecting the entire repertoire of druggable gene alterations, therefore it is gradually becoming a dominating technology in LC molecular diagnosis.

Advancing neoadjuvant therapies in resectable non-small cell lung cancer: implications for novel treatment strategies and biomarker discovery

The delivery of neoadjuvant and perioperative therapies for non-small cell lung cancer has been radically altered by significant advances and by the incorporation of targeted therapies as well as immune checkpoint inhibitors alone or alongside conventional chemotherapy. This evolution has been particularly notable in the incorporation of immunotherapy and targeted therapy into the treatment of resectable NSCLC, where recent FDA approvals of drugs such as nivolumab and pembrolizumab, in combination with platinum doublet chemotherapy, have led to considerable improvements in pathological complete response rates and the potential for enhanced long-term survival outcomes. This review emphasizes the growing importance of biomarkers in optimizing treatment selection and explores the impact of emerging studies that challenge existing treatment paradigms and investigate novel therapeutic combinations poised to redefine standard of care practices. Furthermore, the discussion extends to the unmet needs within perioperative treatment assessment and prognostication, highlighting the prospective value of biomarkers in evaluating treatment responses and prognosis.

Optimizing perioperative treatment for potentially resectable stage III squamous cell lung carcinoma: promising results of a condensed four-cycle regimen with tislelizumaband chemotherapy

BACKGROUND

The standard care for resectable non-small cell lung cancer (NSCLC) involves perioperative therapy combining chemotherapy and immune checkpoint inhibitors, typically lasting 6 to 12 months. However, the optimal treatment strategies for potentially resectable squamous cell lung carcinoma (SCC) remain unclear. This Phase 2 trial aimed to assess the efficacy and safety of a condensed four-cycle perioperative treatment regimen with tislelizumab combined with chemotherapy in patients with potentially resectable stage III SCC.

METHODS

Patients with potentially resectable stage IIIA-IIIB (N2) SCC received intravenous tislelizumab, albumin-bound paclitaxel, and carboplatin for up to four cycles. The primary endpoints were major pathologic response (MPR) and incidence of treatment-related adverse events. Safety and potential biomarkers for efficacy prediction were also assessed.

RESULTS

Among 35 enrolled patients, 32 underwent surgery with R0 resection achieved in all cases. MPR was achieved in 24 patients and pathological complete response (pCR) in 14 patients. Radiographic objective response was observed in 31 patients. The 12-month and 24-month event-free survival rate was 85.7 and 61.0%, respectively. Four patients experienced grade 3 or 4 adverse events. Tumor tissue based next-generation sequencing revealed the potential associations between several biomarkers and pathological response, including tumor neoantigen burden score, 18-gene expression profile score, CD8 + T cells, M1/M2 macrophages ratio and interferon-gamma expression level. Besides, circulating tumor DNA (ctDNA) dynamics and concentration were also associated with pathological response and the presence of ctDNA at postoperative month 1 was a strong predictor for disease relapse. Furthermore, metagenomic sequencing in bronchoalveolar lavage fluid demonstrated Streptococcus was the most abundant genus in the pCR group.

CONCLUSIONS

A condensed four-cycle perioperative treatment regimen of tislelizumab combined with chemotherapy demonstrated promising efficacy and manageable toxicities in potentially resectable stage III SCC. Specific biomarkers showed potential for predicting treatment efficacy and the mechanism of superior antitumor response of pCR patients was preliminarily and indirectly explored.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05024266. Registered August 27, 2021.

Development of new techniques and clinical applications of liquid biopsy in lung cancer management

Lung cancer is an exceedingly malignant tumor reported as having the highest morbidity and mortality of any cancer worldwide, thus posing a great threat to global health. Despite the growing demand for precision medicine, current methods for early clinical detection, treatment and prognosis monitoring in lung cancer are hampered by certain bottlenecks. Studies have found that during the formation and development of a tumor, molecular substances carrying tumor-related genetic information can be released into body fluids. Liquid biopsy (LB), a method for detecting these tumor-related markers in body fluids, maybe a way to make progress in these bottlenecks. In recent years, LB technology has undergone rapid advancements. Therefore, this review will provide information on technical updates to LB and its potential clinical applications, evaluate its effectiveness for specific applications, discuss the existing limitations of LB, and present a look forward to possible future clinical applications. Specifically, this paper will introduce technical updates from the prospectives of engineering breakthroughs in the detection of membrane-based LB biomarkers and other improvements in sequencing technology. Additionally, it will summarize the latest applications of liquid biopsy for the early detection, diagnosis, treatment, and prognosis of lung cancer. We will present the interconnectedness of clinical and laboratory issues and the interplay of technology and application in LB today.

Bridging horizons beyond CIRCULATE-Japan: a new paradigm in molecular residual disease detection via whole genome sequencing-based circulating tumor DNA assay

Circulating tumor DNA (ctDNA) is the fraction of cell-free DNA in patient blood that originates from a tumor. Advances in DNA sequencing technologies and our understanding of the molecular biology of tumors have increased interest in exploiting ctDNA to facilitate detection of molecular residual disease (MRD). Analysis of ctDNA as a promising MRD biomarker of solid malignancies has a central role in precision medicine initiatives exemplified by our CIRCULATE-Japan project involving patients with resectable colorectal cancer. Notably, the project underscores the prognostic significance of the ctDNA status at 4 weeks post-surgery and its correlation to adjuvant therapy efficacy at interim analysis. This substantiates the hypothesis that MRD is a critical prognostic indicator of relapse in patients with colorectal cancer. Despite remarkable advancements, challenges endure, primarily attributable to the exceedingly low ctDNA concentration in peripheral blood, particularly in scenarios involving low tumor shedding and the intrinsic error rates of current sequencing technologies. These complications necessitate more sensitive and sophisticated assays to verify the clinical utility of MRD across all solid tumors. Whole genome sequencing (WGS)-based tumor-informed MRD assays have recently demonstrated the ability to detect ctDNA in the parts-per-million range. This review delineates the current landscape of MRD assays, highlighting WGS-based approaches as the forefront technique in ctDNA analysis. Additionally, it introduces our upcoming endeavor, WGS-based pan-cancer MRD detection via ctDNA, in our forthcoming project, SCRUM-Japan MONSTAR-SCREEN-3.

Personalized, tumor-informed, circulating tumor DNA assay for detecting minimal residual disease in non-small cell lung cancer patients receiving curative treatments

BACKGROUND

Circulating tumor DNA (ctDNA) has emerged as a prognostic and predictive biomarker for detection of minimal residual disease (MRD), monitoring treatment response, and early detection of recurrence in cancer patients. In this study, we explored the utility of ctDNA-based MRD detection to predict recurrence in a real-world cohort of primarily early-stage non-small cell lung cancer (NSCLC) patients treated with curative intent.

METHODS

Longitudinal plasma samples were collected post curative-intent treatment from 36 patients with stage I-IV NSCLC. A personalized, tumor-informed assay was used to detect and quantify ctDNA in plasma samples.

RESULTS

Of the 24 patients with plasma samples available during the MRD window (within 6 months of curative surgery and before adjuvant therapy), ctDNA was detectable in two patients. Patients with ctDNA-positivity during the MRD window were 15 times more likely to recur compared to ctDNA-negative patients (HR: 15.0, 95% CI: 1.0-253.0, p = 0.010). At any time post-curative intent treatment, ctDNA-positivity was associated with significantly poorer recurrence-free survival compared to persistently ctDNA-negative patients (p < 0.0001).

CONCLUSION

Our real-world data indicate that longitudinal, personalized, tumor-informed ctDNA monitoring is a valuable tool in patients with NSCLC receiving curative treatment to identify patients at high risk for recurrence.

Liquid biopsy techniques and lung cancer: diagnosis, monitoring and evaluation

Lung cancer stands as the most prevalent form of cancer globally, posing a significant threat to human well-being. Due to the lack of effective and accurate early diagnostic methods, many patients are diagnosed with advanced lung cancer. Although surgical resection is still a potential means of eradicating lung cancer, patients with advanced lung cancer usually miss the best chance for surgical treatment, and even after surgical resection patients may still experience tumor recurrence. Additionally, chemotherapy, the mainstay of treatment for patients with advanced lung cancer, has the potential to be chemo-resistant, resulting in poor clinical outcomes. The emergence of liquid biopsies has garnered considerable attention owing to their noninvasive nature and the ability for continuous sampling. Technological advancements have propelled circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), extracellular vesicles (EVs), tumor metabolites, tumor-educated platelets (TEPs), and tumor-associated antigens (TAA) to the forefront as key liquid biopsy biomarkers, demonstrating intriguing and encouraging results for early diagnosis and prognostic evaluation of lung cancer. This review provides an overview of molecular biomarkers and assays utilized in liquid biopsies for lung cancer, encompassing CTCs, ctDNA, non-coding RNA (ncRNA), EVs, tumor metabolites, TAAs and TEPs. Furthermore, we expound on the practical applications of liquid biopsies, including early diagnosis, treatment response monitoring, prognostic evaluation, and recurrence monitoring in the context of lung cancer.

Circulating Tumor DNA in the Immediate Postoperative Setting

BACKGROUND

Circulating tumor DNA (ctDNA) has emerged as an accurate real-time biomarker of disease status across many solid tumor types. Most studies evaluating the utility of ctDNA have focused on time points weeks to months after surgery, which, for many cancer types, is significantly later than decision-making time points for adjuvant treatment. In this systematic review, we summarize the state of the literature on the feasibility of using ctDNA as a biomarker in the immediate postoperative period.

METHODS

We performed a systematic review evaluating the early kinetics, defined here as 3 days of ctDNA in patients who underwent curative-intent surgery.

RESULTS

Among the 2057 studies identified, eight cohort studies met the criteria for evaluation. Across six different cancer types, all studies showed an increased risk of cancer recurrence in patients with detectable ctDNA in the immediate postoperative period.

CONCLUSION

While ctDNA clearance kinetics appear to vary based on tumor type, across all studies detectable ctDNA after surgery was predictive of recurrence, suggesting early postoperative time points could be feasibly used for determining minimal residual disease. However, larger studies need to be performed to better understand the precise kinetics of ctDNA clearance across different cancer types as well as to determine optimal postoperative time points.

Postoperative ctDNA in indicating the recurrence risk and monitoring the effect of adjuvant therapy in surgical non-small cell lung cancer

BACKGROUND

Circulating tumor DNA (ctDNA) has emerged as a potential novel biomarker to predict molecular residual disease (MRD) in lung cancer after definitive treatment. Herein, we investigated the value of ctDNA in prognosing risk of relapse and monitoring the effect of adjuvant therapy in surgical non-small cell lung cancer (NSCLC).

METHODS

We enrolled 58 NSCLC patients in a real-world setting, and 58 tumor tissues and 325 plasma samples were analyzed. Tumor tissues and plasma samples were subjected to targeted next-generation sequencing (NGS) of 1021 cancer-related and ultra-deep targeted NGS covering 338 genes, respectively.

RESULTS

ctDNA was detected in 31.0% of cases at the first postoperative time, which was associated with advanced tumor stage, T stage and KEAP1 or GRIN2A mutations in tissues. ctDNA positivity at landmark and longitudinal indicated the shorter disease-free survival. For patients with ctDNA positivity at the first postoperative time, regardless of adjuvant therapy, all patients who were persistently ctDNA positive during postoperative surveillance had disease recurrence. Among the patients who were ctDNA negative, only two patients (15.4%, 2/13) receiving adjuvant therapy relapsed, while one patient (50.0%, 1/2) without adjuvant therapy relapsed. For the first postoperative ctDNA negative patients, the recurrence rate of patients with adjuvant therapy was and higher than without adjuvant therapy (22.6% [7/31] vs. 11.1% [1/9]). The patients who became ctDNA positive may also benefit from intervention therapy.

CONCLUSION

Postoperative ctDNA is a prognostic marker, and ctDNA-detection may facilitate personalized adjuvant therapy, and applying adjuvant therapy to the patients with detectable ctDNA could bring clinical benefits for them.

ctDNA-based minimal residual disease detection in lung cancer patients treated with curative intended chemoradiotherapy using a clinically transferable approach

BACKGROUND

Reliable biomarkers are needed to identify tumor recurrence of non-small cell lung cancer (NSCLC) patients after chemoradiotherapy (CRT) with curative intent. This could improve consolidation therapy of progressing patients. However, the approach of existing studies has limited transferability to the clinic.

MATERIALS AND METHODS

A retrospective analysis of 135 plasma samples from 56 inoperable NSCLC patients who received CRT with curative intent was performed. Plasma samples collected at baseline, at the first check-up (average 1.6 months post-RT), and at the second check-up (average 4.5 months post-RT) were analyzed by deep sequencing with a commercially available cancer personalized profiling strategy (CAPP-Seq) using a tumor-agnostic approach.

RESULTS

Detection of circulating tumor DNA (ctDNA) at 4.5 months after therapy was significantly associated with higher odds of tumor recurrence (OR: 5.4 (CI: 1.1-31), Fisher's exact test: p-value = 0.022), and shorter recurrence-free survival (RFS) (HR: 4.1 (CI: 1.7-10); log-rank test: p-value = 9e-04). In contrast, detection of ctDNA at 1.6 months after therapy was not associated with higher odds of tumor recurrence (OR: 2.7 (CI: 0.67-12), Fisher's exact test: p-value = 0.13) or shorter RFS (HR: 1.5 (CI: 0.67-3.3); log-rank test: p-value = 0.32).

CONCLUSION

This study demonstrates that the detection of ctDNA can be used to identify minimal residual disease 4.5 months after CRT in NSCLC patients using a commercially available kit and a tumor-agnostic approach. Furthermore, the time point of collecting the plasma sample after CRT has decisive importance for the prognostic value of ctDNA.

MICRO ABSTRACT

This study analysed 135 plasma samples from 56 NSCLC patients treated with curative intent chemoradiotherapy using a tumor-agnostic approach. Detecting ctDNA at 4.5 months post-treatment was linked to higher recurrence odds, indicating ctDNA's potential as a biomarker for identifying residual disease after treatment with curative intent. Importantly, the study emphasizes the importance of timing for accurate ctDNA analysis results.

Biomarkers of minimal residual disease and treatment

Minimal residual disease (MRD) has been defined as a very small numbers of cancer cells that remain in the body after curative treatment. Its presence or absence will ultimately determine prognosis. With the introduction of new technologies the presence of MRD in patients with solid tumours can be detected and characterized. As MRD predicts future relapse, be it early or late treatment failure, in an otherwise asymptomatic patient its treatment and when to start treatment remains to be determined. Thus the concepts of personalized medicine using different biomarkers to classify the biological properties of MRD maybe come possible. Based on this determinations it may be possible to use targeted therapies rather than all patients with the same type of cancer receiving a standard treatment. However, it is important to understand the limitations of the different technologies, what these techniques are detecting and how they may help in the treatment of patients with cancer. The majority of published studies are in patients with metastatic cancer and there are few reports in patients with MRD. In this chapter the concept of MRD, the methods used to detect it and what treatments may be effective based on the biological characteristics of the tumour cells as determined by different biomarkers is reviewed. MRD depends on the phenotypic properties of the tumour cells to survive in their new environment and the anti-tumour immune response. This is a dynamic process and changes with time in the wake of immunosuppression caused by the tumour cells and/or the effects of treatment to select resistant tumour cells. With the use of biomarkers to typify the characteristics of MRD and the development of new drugs a personalized treatment can be designed rather than all patients given the same treatment. Patients who are initially negative for MRD may not require further treatment with liquid biopsies used to monitor the patients during follow-up in order to detect those patients who may become MRD positive. The liquid biopsy used during the follow up of MRD positive patients can be used to detect changes in the biological properties of the tumour cells and thus may need treatment changes to overcome tumour cell resistance.

Perioperative Treatment Strategies in EGFR-Mutant Early-Stage NSCLC: Current Evidence and Future Challenges

Treatment with 3 years of adjuvant osimertinib is considered a new standard in patients with completely resected stage I to IIIA NSCLC harboring a common sensitizing EGFR mutation. This therapeutic approach significantly prolonged the disease-free survival and the overall survival versus placebo and revealed a significant role in preventing the occurrence of brain metastases. However, many unanswered questions remain, including the optimal duration of this therapy, whether all patients benefit from adjuvant osimertinib, and the role of adjuvant chemotherapy in this population. Indeed, there is a renewed interest in neoadjuvant strategies with targeted therapies in resectable NSCLC harboring oncogenic drivers. In light of these considerations, we discuss the past and current treatment options, and the clinical challenges that should be addressed to optimize the treatment outcomes in this patient population.

Liquid biopsy in lung cancer

Lung cancer is a highly prevalent malignancy worldwide and the primary cause of mortality. The absence of systematic and standardized diagnostic approaches for identifying potential pulmonary nodules, early-stage cancers, and indeterminate tumors has led clinicians to consider tissue biopsy and pathological sections as the preferred method for clinical diagnosis, often regarded as the gold standard. The conventional tissue biopsy is an invasive procedure that does not adequately capture the diverse characteristics and evolving nature of tumors. Recently, the concept of 'liquid biopsy' has gained considerable attention as a promising solution. Liquid biopsy is a non-invasive approach that facilitates repeated analysis, enabling real-time monitoring of tumor recurrence, metastasis, and response to treatment. Currently, liquid biopsy includes circulating tumor cells, circulating cell-free DNA, circulating tumor DNA, circulating cell-free RNA, extracellular vesicles, and other proteins and metabolites. With rapid progress in molecular technology, liquid biopsy has emerged as a highly promising and intriguing approach, yielding compelling results. This article critically examines the significant role and potential clinical implications of liquid biopsy in the diagnosis, treatment, and prognosis of lung cancer.

Prognostic value of preoperative circulating tumor DNA in non-small cell lung cancer: a systematic review and meta-analysis

BACKGROUND

Several recent studies have reported the increasing application of preoperative circulating tumor DNA (ctDNA) as a biomarker of tumor burden for guiding potential postoperative treatment strategies.

METHODS

A meta-analysis of prospective/retrospective cohort studies was conducted to compare the prognosis of preoperatively genetically positive and genetically negative NSCLC patients. The endpoints used in the included studies were overall survival (OS) and recurrence-free survival (RFS). The objective of the meta-analysis was to comprehensively explore the prognostic value of preoperative ctDNA for patients with non-small-cell lung cancer (NSCLC) and its significance in guiding postoperative adjuvant therapy (AT) in patients with NSCLC.

RESULTS

The preliminary analysis identified 1565 studies, among which only 11 studies fulfilled the eligibility criteria and were finally included in the present systematic review and meta-analysis. The statistical results revealed that the expression of preoperative ctDNA was associated with worse RFS (HR = 3.00; 95% CI 2.26-3.98; I2 = 0%) and OS (HR = 2.77; 95% CI 1.67-4.58; I2 = 0%), particularly in lung adenocarcinoma (LUAD) patients (RFS: HR = 3.46; 95% CI 2.37-5.05; I2 = 0%; OS: HR = 3.52; 95% CI 1.91-6.49; I2 = 0%) and patients with I-II stage of NSCLC (RFS: HR = 2.84; 95% CI 1.88-4.29; I2 = 0%; OS: HR = 2.60; 95% CI 1.43-4.74; I2 = 0%). Moreover, compared to patients with negative preoperative ctDNA, patients with positive preoperative ctDNA presented greater survival benefits (HR = 0.39; 95% CI 0.22-0.67; I2 = 2%) from postoperative AT.

CONCLUSION

The evaluation of the prognostic value of preoperative ctDNA revealed that preoperative ctDNA might be used as a prognostic biomarker for patients with LUAD or those with stage I-II NSCLC. In addition, postoperative AT is recommended for NSCLC patients with positive preoperative ctDNA, regardless of the disease stage and subtype.

Analysis of circulating tumor DNA identifies distinct therapeutic response to intraperitoneal and intravenous paclitaxel plus S-1 in gastric cancer patients with peritoneal metastasis

Background

Circulating tumor DNA (ctDNA) is a promising technique for predicting curative effects and monitoring tumor recurrence. The utility of ctDNA for gastric cancer with peritoneal dissemination remains elusive.

Objectives

To assess the feasibility of ctDNA in predicting tumor response to chemotherapy in gastric cancer with peritoneal dissemination.

Design

This was a prospective study.

Methods

We enrolled 30 patients with gastric cancer peritoneal metastasis, treated with intraperitoneal and intravenous paclitaxel plus S-1. Peripheral blood samples of patients were prospectively collected at baseline, after treatment initiation accompanied by computed tomography scan and disease progression. Mutational profiles from ctDNA were analyzed to evaluate its association with chemotherapeutic response.

Results

Tumor protein 53 (TP53) was the most frequently altered gene at baseline blood samples. Although baseline TP53 mutation was not related to therapeutic response, patients with TP53 mutation had worse progression-free survival (PFS) and overall survival (OS). Additionally, baseline ctDNA content fraction (CCF) was found to be significantly lower in responders than non-responders. Meanwhile, patients with high CCF had a trend of worse PFS and OS. Combining TP53 alteration and CCF, the prognosis of TP53-wt patients could be further stratified. Patients with CCF-low_TP53-wt had markedly longer survival than those with CCF-high_TP53-wt.

Conclusion

Our study highlighted the significance of ctDNA in predicting potential clinical outcomes in gastric cancer patients during chemotherapy.

Trial registration

ChiCTR-IIR-16009802 (Chinese Clinical Trial Registry).

Efficacy and safety of neoadjuvant immunotherapy protocols and cycles for non-small cell lung cancer: a systematic review and meta-analysis

Objectives

This study evaluated the use of different neoadjuvant immunotherapy cycles and regimens for non-small cell lung cancer.

Materials and methods

Databases were searched for articles published up until December 2023. Data on the major pathologic response (MPR), complete pathologic response (pCR), radiological response, treatment-related adverse events (TRAEs), serious adverse events (SAEs), surgical resection, surgical complications, R0 resection, and conversion to thoracotomy were collected. A subgroup analysis was performed according to the treatment regimens and cycles. Stata/MP software was used for statistical analyses.

Results

In total, 2430 individuals were assessed from 44 studies. Compared with those following neoadjuvant immunotherapy alone (MPR/pCR/TRAEs/SAEs: ES=0.26/0.07/0.43/0.08, 95% CI: 0.18-0.34/0.04-0.10/0.28-0.58/0.04-0.14), the MPR and pCR rates, incidence of TRAEs and SAEs following neoadjuvant chemoimmunotherapy increased significantly (MPR/pCR/TRAEs/SAEs: ES=0.55/0.34/0.81/0.22, 95% CI: 0.48-0.63/0.28-0.41/0.69-0.90/0.13-0.33, P=0.001/0.002/0.009/0.034). No significant differences were found in the surgical resection, surgical complications, R0 resection, or conversion to thoracotomy. In the chemoimmunotherapy group, no statistically significant differences were found in the MPR and pCR rates, incidence of TRAEs and SAEs in the two-cycle, three-cycle and four-cycle groups (MPR/pCR/TRAEs/SAEs: ES=0.50;0.70;0.36/0.32;0.49;0.18/0.95;0.85;0.95/0.34;0.27;0.37, P=0.255/0.215/0.253/0.848). In the ICIs group, there was little change in the MPR and pCR rates, incidence of TRAEs and SAEs in the two-cycle group compared to the three-cycle group. (MPR/pCR/TRAEs/SAEs: ES=0.28;0.20/0.06;0.08/0.45;0.35/0.10;0.02, P=0.696/0.993/0.436/0.638). The neoadjuvant treatment cycle had no significant effect on surgical resection, surgical complications, R0 resection, or conversion to thoracotomy in both regimens.

Conclusion

Neoadjuvant chemoimmunotherapy significantly increased the rate of tumor pathological remission compared to neoadjuvant immunotherapy alone but also increased the incidence of TRAEs and SAEs. The efficacy and safety of neoadjuvant chemoimmunotherapy are found to be favorable when administered for a duration of three cycles, in comparison to both two and four cycles.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/#recordDetails, identifier CRD42023407415.

Minimal residual disease guided radical chemoradiotherapy combined with immunotherapy after neoadjuvant immunochemotherapy followed by adjuvant immunotherapy for esophageal squamous cell cancer (ECMRD-001): a study protocol for a prospective cohort study

Introduction

For locally advanced, inoperable esophageal cancer, concurrent chemoradiotherapy (CCRT) becomes the norm. Combining immunotherapy with radiotherapy has been shown to improve efficacy. Circulating tumor DNA (ctDNA) is a strong predictor of effectiveness and tumor recurrence and is indicative of minimal residual disease (MRD). Patients with inoperable stage II-III esophageal squamous cell carcinoma (ESCC) are enrolled in the ECMRD-001 trial to evaluate changes in MRD status before and after CCRT combined with immunotherapy and adjuvant immunotherapy following neoadjuvant immunochemotherapy.

Methods and analysis

The ECMRD-001 trial is a prospective cohort study. Eligible patients will receive radical concurrent chemoradiotherapy combined with immunotherapy after neoadjuvant immunochemotherapy, followed by adjuvant immunotherapy for at least one year. Follow-up will be up to three years. MRD-related blood and tissue samples and T-cell immunohistobank related blood and tissue samples collected before, during and after treatment and follow-up will be grouped into sample collection time points. The relationship between MRD status at different time points and treatment efficacy is the primary outcome. Correlation between MRD status and immune microenvironment, radiotherapy dose, and tumor recurrence are the secondary outcomes. Examination of ctDNA mutations is the exploratory outcome.

Discussion

ctDNA-based MRD may be a potential predictive marker for the efficacy and tumor recurrence of inoperable ESCC patients. Elevated ctDNA-MRD may predict tumor recurrence earlier than imaging. ctDNA-based MRD analysis and ctDNA-based MRD guided diagnosis and treatment should be implemented into clinical practice to improve efficacy and reduce tumor recurrence of inoperable stage II-III ESCC.

Trial registration

The ECMRD-001 study has been registered at ClinicalTrials.gov as NCT05952661 (July 19, 2023), https://classic.clinicaltrials.gov/ct2/show/NCT05952661.

Is there role of adjuvant radiotherapy after complete resection of locally advanced nonsmall cell lung cancer?

PURPOSE OF REVIEW

This review aims to provide a timely and relevant overview of the role of postoperative radiotherapy (PORT) in completely resected stage IIIA-N2 nonsmall cell lung cancer (NSCLC). Given the controversy surrounding the use of PORT and the emergence of advanced radiation techniques and therapies, this review provides valuable insight into current and potential treatment strategies.

RECENT FINDINGS

The Lung ART and PORT-C trials have provided valuable insights into the efficacy of PORT in stage IIIA-N2 NSCLC. While the results have been mixed, studies have shown that advanced radiation techniques, such as intensity-modulated radiotherapy (IMRT) and proton therapy, can reduce cardiopulmonary toxicities associated with PORT. Molecular targeted therapies and immunotherapies have also shown potential in improving NSCLC treatment outcomes.

SUMMARY

The role of radiotherapy becomes smaller and smaller in new era. However, it is too early to abolish radiotherapy for all the patients after complete resection of locally advanced NSCLC. Nowadays, it is recommended to adopt individualized treatment approaches guided by multidisciplinary team consultations. The integration of IMRT, proton therapy, and emerging therapies offers the potential to enhance treatment efficacy while minimizing toxicity. Further research is needed to optimize the use of PORT and explore the method to identify the patients who can really benefit from PORT.

Adjuvant Therapy-Free Strategy for Stage IB to IIIA Non-Small-Cell Lung Cancer Patients After Radical Resection Based on Longitudinal Undetectable Molecular Residual Disease: Prospective, Multicenter, Single-Arm Study (CTONG 2201)

BACKGROUND

The utility of circulating tumor DNA to monitor molecular residual disease (MRD) has been clinically confirmed to predict disease recurrence in non-small cell lung cancer (NSCLC) patients after radical resection. Patients with longitudinal undetectable MRD show a favorable prognosis and might not benefit from adjuvant therapy.

PATIENTS AND METHODS

The CTONG 2201 trial is a prospective, multicenter, single-arm study (ClinicalTrials.gov identifier, NCT05457049), designed to evaluate the hypothesis that no adjuvant therapy is needed for patients with longitudinal undetectable MRD. Pathologically confirmed stage IB-IIIA NSCLC patients who have undergone radical resection will be screened. Only patients with 2 consecutive rounds of undetectable MRD will be enrolled (first at days 3-10, second at days 30 ± 7 after surgery), and admitted for imaging and MRD monitoring every 3 months without adjuvant therapy. The primary endpoint is the 2-year disease-free survival rate for those with longitudinal undetectable MRD. The recruitment phase began in August 2022 and 180 patients will be enrolled.

CONCLUSIONS

This prospective trial will contribute data to confirm the negative predictive value of MRD on adjuvant therapy for NSCLC patients.

CLINICAL TRIAL REGISTRATION

NCT05457049 (CTONG 2201).

The use of minimal residual disease in thoracic oncology: Gaps between promises and the on-the-ground reality of daily practice

The assessment of minimal residual disease (MRD) from blood samples of patients with resected non-small cell lung carcinoma (NSCLC) is promising and opens up many opportunities for the optimisation of patient care in daily practice. Notably, this includes the potential for escalation or de-escalation of adjuvant therapies. Thus, the evaluation of MRD status can directly contribute to an increase in the overall survival of early stage NSCLC patients and/or limit therapeutic but also "financial" toxicity. Therefore, several clinical trials recently evaluated MRD in early stage NSCLC by integrating and retrospectively comparing the results of MRD assessments. In this context, there is an urgent need to close the gap between clinical research and the use of the evaluation of MRD in routine daily practice. Further action needs to be taken, particularly in evaluating the pertinence of the detection of MRD in prospective interventional clinical studies. This may be done in part by comparing different parameters, such as the techniques used, the different time points and the cutoffs of MRD assessments. This article investigates the assessment of MRD in non-small cell lung cancers, with a special focus on the issues associated with the various assays and the limitations of using circulating free DNA analyses for MRD assessment in early stage lung cancer. Recommendations and tips for the optimisation of MRD evaluation in non-small cell lung cancers are provided.

Management of locally advanced non-small cell lung cancer: State of the art and future directions

Lung cancer is the second most common and the deadliest type of cancer worldwide. Clinically, non-small cell lung cancer (NSCLC) is the most common pathological type of lung cancer; approximately one-third of affected patients have locally advanced NSCLC (LA-NSCLC, stage III NSCLC) at diagnosis. Because of its heterogeneity, LA-NSCLC often requires multidisciplinary assessment. Moreover, the prognosis of affected patients is much below satisfaction, and the efficacy of traditional therapeutic strategies has reached a plateau. With the emergence of targeted therapies and immunotherapies, as well as the continuous development of novel radiotherapies, we have entered an era of novel treatment paradigm for LA-NSCLC. Here, we reviewed the landscape of relevant therapeutic modalities, including adjuvant, neoadjuvant, and perioperative targeted and immune strategies in patients with resectable LA-NSCLC with/without oncogenic alterations; as well as novel combinations of chemoradiation and immunotherapy/targeted therapy in unresectable LA-NSCLC. We addressed the unresolved challenges that remain in the field, and examined future directions to optimize clinical management and increase the cure rate of LA-NSCLC.

Neoadjuvant nivolumab with or without platinum-doublet chemotherapy based on PD-L1 expression in resectable NSCLC (CTONG1804): a multicenter open-label phase II study

This prospective multicenter phase II study evaluated the clinical efficacy of neoadjuvant nivolumab-exclusive (N) and nivolumab-chemotherapy (N/C) combinations based on PD-L1 expression. Eligible patients exhibited resectable clinical stage IIA-IIIB (AJCC 8th edition) NSCLC without EGFR/ALK alterations. Patients received either mono-nivolumab (N) or nivolumab + nab-paclitaxel+ carboplatin (N/C) for three cycles based on PD-L1 expression. The primary endpoint was the major pathological response (MPR). Key secondary endpoints included the pathologic complete response (pCR), objective response rate (ORR), and event-free survival (EFS). Baseline PD-L1 expression and perioperative circulating tumor DNA (ctDNA) status were correlated with pCR and EFS. Fifty-two patients were enrolled, with 46 undergoing surgeries. The MPR was 50.0% (26/52), with 25.0% (13/52) achieving pCR, and 16.7% and 66.7% for patients with PD-L1 ≥ 50% in N and N/C groups, respectively. Thirteen (25.0%) patients experienced grade 3 or higher immune-related adverse events during neoadjuvant treatment. Patients with post-neoadjuvant ctDNA negativity was more likely to have pCR (39.1%) compared with those remained positive (6.7%, odds ratio = 6.14, 95% CI 0.84-Inf, p = 0.077). With a median follow-up of 25.1 months, the 18-month EFS rate was 64.8% (95% CI 51.9-81.0%). For patients with ctDNA- vs. ctDNA + , the 18m-EFS rate was 93.8% vs 47.3% (HR, 0.15; 95% CI 0.04, 0.94; p = 0.005). Immunochemotherapy may serve as an optimal neoadjuvant treatment even for patients with PD-L1 expression ≥ 50%. ctDNA negativity following neoadjuvant treatment and surgery could help identify superior pathological and survival benefits, which requires further confirmation in a prospective clinical trial (NCT04015778).

Circulating Tumor DNA Is a Variant of Liquid Biopsy with Predictive and Prognostic Clinical Value in Breast Cancer Patients

This paper introduces the reader to the field of liquid biopsies and cell-free nucleic acids, focusing on circulating tumor DNA (ctDNA) in breast cancer (BC). BC is the most common type of cancer in women, and progress with regard to treatment has been made in recent years. Despite this, there remain a number of unresolved issues in the treatment of BC; in particular, early detection and diagnosis, reliable markers of response to treatment and for the prediction of recurrence and metastasis, especially for unfavorable subtypes, are needed. It is also important to identify biomarkers for the assessment of drug resistance and for disease monitoring. Our work is devoted to ctDNA, which may be such a marker. Here, we describe its main characteristics and potential applications in clinical oncology. This review considers the results of studies devoted to the analysis of the prognostic and predictive roles of various methods for the determination of ctDNA in BC patients. Currently known epigenetic changes in ctDNA with clinical significance are reviewed. The possibility of using ctDNA as a predictive and prognostic marker for monitoring BC and predicting the recurrence and metastasis of cancer is also discussed, which may become an important part of a precision approach to the treatment of BC.

Circulating tumor DNA (ctDNA)-based minimal residual disease in non-small cell lung cancer

Lung cancer is the second most common cancer worldwide and the leading cause of cancer-related fatalities, with non-small cell lung cancer (NSCLC) accounting for 85% of all lung cancers. Over the past forty years, patients with NSCLC have had a 5-year survival rate of only 16%, despite improvements in chemotherapy, targeted therapy, and immunotherapy. Circulating tumor DNA (ctDNA) in blood can be used to identify minimal residual disease (MRD), and ctDNA-based MRD has been shown to be of significance in prognostic assessment, recurrence monitoring, risk of recurrence assessment, efficacy monitoring, and therapeutic intervention decisions in NSCLC. The level of MRD can be obtained by monitoring ctDNA to provide guidance for more precise and personalized treatment, the scientific feasibility of which could dramatically modify lung cancer treatment paradigm. In this review, we present a comprehensive review of MRD studies in NSCLC and focus on the application of ctDNA-based MRD in different stages of NSCLC in current clinical practice.

Residual circulating tumor DNA after adjuvant chemotherapy effectively predicts recurrence of stage II-III gastric cancer

BACKGROUND

Circulating tumor DNA (ctDNA) is a promising biomarker for predicting relapse in multiple solid cancers. However, the predictive value of ctDNA for disease recurrence remains indefinite in locoregional gastric cancer (GC). Here, we aimed to evaluate the predictive value of ctDNA in this context.

METHODS

From 2016 to 2019, 100 patients with stage II/III resectable GC were recruited in this prospective cohort study (NCT02887612). Primary tumors were collected during surgical resection, and plasma samples were collected perioperatively and within 3 months after adjuvant chemotherapy (ACT). Somatic variants were captured via a targeted sequencing panel of 425 cancer-related genes. The plasma was defined as ctDNA-positive only if one or more variants detected in the plasma were presented in at least 2% of the primary tumors.

RESULTS

Compared with ctDNA-negative patients, patients with positive postoperative ctDNA had moderately higher risk of recurrence [hazard ratio (HR) = 2.74, 95% confidence interval (CI) = 1.37-5.48; P = 0.003], while patients with positive post-ACT ctDNA showed remarkably higher risk (HR = 14.99, 95% CI = 3.08-72.96; P < 0.001). Multivariate analyses indicated that both postoperative and post-ACT ctDNA positivity were independent predictors of recurrence-free survival (RFS). Moreover, post-ACT ctDNA achieved better predictive performance (sensitivity, 77.8%; specificity, 90.6%) than both postoperative ctDNA and serial cancer antigen. A comprehensive model incorporating ctDNA for recurrence risk prediction showed a higher C-index (0.78; 95% CI = 0.71-0.84) than the model without ctDNA (0.71; 95% CI = 0.64-0.79; P = 0.009).

CONCLUSIONS

Residual ctDNA after ACT effectively predicts high recurrence risk in stage II/III GC, and the combination of tissue-based and circulating tumor features could achieve better risk prediction.

Clinical definition of secondary resistance to immunotherapy in non-small cell lung cancer

Immune checkpoint inhibitors (PD-1/PD-L1 and CTLA-4 blockade) have revolutionized the treatment landscape in non-small cell lung cancer (NSCLC). Secondary resistance to immunotherapy (IO), which poses a substantial challenge in clinical settings, occurs in several initial responders. Currently, new treatment approaches have been extensively evaluated in investigational studies for these patients to tackle this difficult problem; however, the lack of consistency in clinical definition, uniform criteria for enrollment in clinical trials, and interpretation of results remain significant hurdles to progress. Thus, our expert panel comprehensively synthesized data from current studies to propose a practical clinical definition of secondary resistance to immunotherapy in NSCLC in metastatic and neoadjuvant settings. In addition to patients who received IO alone (including IO-IO combinations), we also generated a definition for patients treated with chemotherapy plus IO. This consensus aimed to provide guidance for clinical trial design and facilitate future discussions with investigators. It should be noted that additional updates in this consensus are required when new data is available.

Circulating tumor DNA as liquid biopsy in lung cancer: Biological characteristics and clinical integration

Lung cancer maintains high morbidity and mortality rate globally despite significant advancements in diagnosis and treatment in the era of precision medicine. Pathological analysis of tumor tissue, the current gold standard for lung cancer diagnosis, is intrusive and intrinsically confined to evaluating the limited amount of tissues that could be physically extracted. However, tissue biopsy has several limitations, including the invasiveness of the procedure and difficulty in obtaining samples for patients at advanced stages., there Additionally,has been no major breakthrough in tumor biomarkers with high specificity and sensitivity, particularly for early-stage lung cancer. Liquid biopsy has been considered a feasible auxiliary tool for tearly dianosis, evaluating treatment responses and monitoring prognosis of lung cancer. Circulating tumor DNA (ctDNA), an ideal biomarker of liquid biopsy, has emerged as one of the most reliable tools for monitoring tumor processes at molecular levels. Herein, this review focuses on tumor heterogeneity to elucidate the superiority of liquid biopsy and retrospectively discussdeciphersolution. We systematically elaborate ctDNA biological characteristics, introduce methods for ctDNA detection, and discuss the current role of plasma ctDNA in lung cancer management. Finally, we summarize the drawbacks of ctDNA analysis and highlight its potential clinical application in lung cancer.

Non-invasive monitoring of neoadjuvant radiation therapy response in soft tissue sarcomas by multiparametric MRI and quantification of circulating tumor DNA-A study protocol

BACKGROUND

Wide resection remains the cornerstone of localized soft-tissue sarcomas (STS) treatment. Neoadjuvant radiation therapy (NRT) may decrease the risk of local recurrences; however, its effectiveness for different histological STS subtypes has not been systematically investigated. The proposed prospective study evaluates the NRT response in STS using liquid biopsies and the correlation of multiparametric magnetic resonance imaging (mpMRI) with histopathology and immunohistochemistry.

METHODS

Patients with localized high-grade STS, who qualify for NRT, are included in this study.

LIQUID BIOPSIES

Quantification of circulating tumor DNA (ctDNA) in patient blood samples is performed by targeted next-generation sequencing. Soft-tissue sarcoma subtype-specific panel sequencing in combination with patient-specific exome sequencing allows the detection of individual structural variants and point mutations. Circulating free DNA is isolated from peritherapeutically collected patient plasma samples and ctDNA quantified therein. Identification of breakpoints is carried out using FACTERA. Bioinformatic analysis is performed using samtools, picard, fgbio, and the MIRACUM Pipeline.

MPMRI

Combination of conventional MRI sequences with diffusion-weighted imaging, intravoxel-incoherent motion, and dynamic contrast enhancement. Multiparametric MRI is performed before, during, and after NRT. We aim to correlate mpMRI data with the resected specimen's macroscopical, histological, and immunohistochemical findings.

RESULTS

Preliminary data support the notion that quantification of ctDNA in combination with tumor mass characterization through co-registration of mpMRI and histopathology can predict NRT response of STS.

CLINICAL RELEVANCE

The methods presented in this prospective study are necessary to assess therapy response in heterogeneous tumors and lay the foundation of future patient- and tumor-specific therapy concepts. These methods can be applied to various tumor entities. Thus, the participation and support of a wider group of oncologic surgeons are needed to validate these findings on a larger patient cohort.

Individualized tumor-informed circulating tumor DNA analysis for postoperative monitoring of non-small cell lung cancer

We report a personalized tumor-informed technology, Patient-specific pROgnostic and Potential tHErapeutic marker Tracking (PROPHET) using deep sequencing of 50 patient-specific variants to detect molecular residual disease (MRD) with a limit of detection of 0.004%. PROPHET and state-of-the-art fixed-panel assays were applied to 760 plasma samples from 181 prospectively enrolled early stage non-small cell lung cancer patients. PROPHET shows higher sensitivity of 45% at baseline with circulating tumor DNA (ctDNA). It outperforms fixed-panel assays in prognostic analysis and demonstrates a median lead-time of 299 days to radiologically confirmed recurrence. Personalized non-canonical variants account for 98.2% with prognostic effects similar to canonical variants. The proposed tumor-node-metastasis-blood (TNMB) classification surpasses TNM staging for prognostic prediction at the decision point of adjuvant treatment. PROPHET shows potential to evaluate the effect of adjuvant therapy and serve as an arbiter of the equivocal radiological diagnosis. These findings highlight the potential advantages of personalized cancer techniques in MRD detection.

circulating tumor DNA in the immediate post-operative setting

Background

Circulating tumor DNA (ctDNA) has emerged as an accurate real-time biomarker of disease status across most solid tumor types. Most studies evaluating the utility of ctDNA have focused on time points weeks to months after surgery, which for many cancer types, is significantly later than decision-making time points for adjuvant treatment. In this systematic review, we summarize the state of the literature on the feasibility of using ctDNA as a biomarker in the immediate postoperative period.

Methods

We performed a systematic review evaluating the early kinetics, defined here as three days, of ctDNA in patients who underwent curative-intent surgery across several cancer types.

Results

Among the 2057 studies identified, we evaluated eight cohort studies with ctDNA levels measured within the first three days after surgery. Across six different cancer types, all studies showed an increased risk of cancer recurrence in patients with a positive early postoperative ctDNA level.

Discussion

While ctDNA clearance kinetics appear to vary based on tumor type, across all studies- detectable ctDNA after surgery was predictive of recurrence, suggesting early postoperative timepoints could be feasibly used for determining minimal residual disease. However, larger studies need to be performed to better understand the precise kinetics of ctDNA clearance across different cancer types as well as to determine optimal postoperative time points.

Synopsis

This systematic review analyzed the use of ctDNA as a biomarker for minimal residual disease detection in the early postoperative setting and found that ctDNA detection within three days after surgery is associated with an increased risk of recurrence.

Immune-checkpoint inhibition for resectable non-small-cell lung cancer - opportunities and challenges

Therapeutic strategies harnessing the immune system to eliminate tumour cells have been successfully used for several cancer types, including in patients with advanced-stage non-small-cell lung cancer (NSCLC). In these patients, immune-checkpoint inhibitors (ICIs) can provide durable responses and improve overall survival either as monotherapy, or combined with chemotherapy or other immunotherapeutic agents. However, the implementation of ICIs in early stage NSCLC has been hampered by the continuous struggle to develop robust end points to assess their efficacy in this setting, especially those enabling a fast and reproducible evaluation of the clinical activity of neoadjuvant strategies. Several trials are testing ICIs, alone or in combination with chemotherapy, in early stage NSCLC as an adjuvant, neoadjuvant or perioperative approach. As a novelty, most trials in the neoadjuvant setting have adopted pathological response as a primary end point. ICIs have been approved for use in the neoadjuvant and adjuvant settings on the basis of event-free survival and disease-free survival benefit, respectively; however, the correlation of these end points with overall survival remains unclear in these settings. Unresolved challenges for the optimal use of ICIs with curative intent include concerns about their applicability in daily clinical practice and about improving patient selection based on predictive biomarkers or assessment of pathological response and minimal residual disease. In this Review, we discuss the rationale, available strategies and current trial landscape for the implementation of ICIs in patients with resectable NSCLC, and we further elaborate on future approaches to optimize their clinical benefit.

Multimodal analysis of cell-free DNA whole-methylome sequencing for cancer detection and localization

Multimodal epigenetic characterization of cell-free DNA (cfDNA) could improve the performance of blood-based early cancer detection. However, integrative profiling of cfDNA methylome and fragmentome has been technologically challenging. Here, we adapt an enzyme-mediated methylation sequencing method for comprehensive analysis of genome-wide cfDNA methylation, fragmentation, and copy number alteration (CNA) characteristics for enhanced cancer detection. We apply this method to plasma samples of 497 healthy controls and 780 patients of seven cancer types and develop an ensemble classifier by incorporating methylation, fragmentation, and CNA features. In the test cohort, our approach achieves an area under the curve value of 0.966 for overall cancer detection. Detection sensitivity for early-stage patients achieves 73% at 99% specificity. Finally, we demonstrate the feasibility to accurately localize the origin of cancer signals with combined methylation and fragmentation profiling of tissue-specific accessible chromatin regions. Overall, this proof-of-concept study provides a technical platform to utilize multimodal cfDNA features for improved cancer detection.

The Clinical Significance of Circulating Tumor DNA for Minimal Residual Disease Identification in Early-Stage Non-Small Cell Lung Cancer

Lung cancer (LC) is the deadliest malignancy worldwide. In an operable stage I-III patient setting, the detection of minimal residual disease (MRD) after curative treatment could identify patients at higher risk of relapse. In this context, the study of circulating tumor DNA (ctDNA) is emerging as a useful tool to identify patients who could benefit from an adjuvant treatment, and patients who could avoid adverse events related to a more aggressive clinical management. On the other hand, ctDNA profiling presents technical, biological and standardization challenges before entering clinical practice as a decisional tool. In this paper, we review the latest advances regarding the role of ctDNA in identifying MRD and in predicting patients' prognosis, with a particular focus on clinical trials investigating the potential of ctDNA, the technical challenges to address and the biological parameters that influence the MRD detection.

A Review of Biomarkers and Their Clinical Impact in Resected Early-Stage Non-Small-Cell Lung Cancer

The postoperative survival of early-stage non-small-cell lung cancer (NSCLC) patients remains unsatisfactory. In this review, we examined the relevant literature to ascertain the prognostic effect of related indicators on early-stage NSCLC. The prognostic effects of the epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), mesenchymal-epithelial transition (MET), C-ros oncogene 1 (ROS1), or tumour protein p53 (TP53) alterations in resected NSCLC remains debatable. Kirsten rat sarcoma viral oncogene homologue (KRAS) alterations indicate unfavourable outcomes in early-stage NSCLC. Meanwhile, adjuvant or neoadjuvant EGFR-targeted agents can substantially improve prognosis in early-stage NSCLC with EGFR alterations. Based on the summary of current studies, resected NSCLC patients with overexpression of programmed death-ligand 1 (PD-L1) had worsening survival. Conversely, PD-L1 or PD-1 inhibitors can substantially improve patient survival. Considering blood biomarkers, perioperative peripheral venous circulating tumour cells (CTCs) and pulmonary venous CTCs predicted unfavourable prognoses and led to distant metastases. Similarly, patients with detectable perioperative circulating tumour DNA (ctDNA) also had reduced survival. Moreover, patients with perioperatively elevated carcinoembryonic antigen (CEA) in the circulation predicted significantly worse survival outcomes. In the future, we will incorporate mutated genes, immune checkpoints, and blood-based biomarkers by applying artificial intelligence (AI) to construct prognostic models that predict patient survival accurately and guide individualised treatment.