Circulating Tumor DNA as a Prognostic Biomarker in Localized Non-small Cell Lung Cancer

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.

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.

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.

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.

Prognostic value of circulating tumor DNA in operable non-small cell lung cancer: a systematic review and reconstructed individual patient-data based meta-analysis

BACKGROUND

This reconstructed individual patient data (IPD)-based meta-analysis is aimed to summarize the current findings and comprehensively investigate the predictive value of circulating tumor DNA (ctDNA) in operable non-small cell lung cancer (NSCLC).

METHODS

PubMed, Cochrane and Embase were searched to include potentially eligible studies. The primary outcomes included progression-free survival (DFS) by ctDNA status at baseline, postoperative, and longitudinal timepoints. The IPD-based survival data was retracted and used in reconstructed IPD-based meta-analysis. Subgroup analysis was implemented based on the baseline characteristics.

RESULTS

Totally, 28 studies were involved, including 15 full-length articles (1686 patients) for IPD-based synthesis and 20 studies for conventional meta-analysis. The IPD-based meta-analysis discovered that patients with positive ctDNA status at the baseline (hazard ratio, HR = 3.73, 95% confidential interval, CI: 2.95-4.72), postoperative (3.96, 2.19-7.16), or longitudinal timepoints (12.33, 8.72-17.43) showed significantly higher risk of recurrence. Patients with persistent ctDNA-negative status had the lowest recurrence rate, and the negative conversion of ctDNA from baseline to postoperative timepoints was correlated with elevated DFS. Subgroup analyses suggested that stage II-III patients with ctDNA-positive status may achieve preferable therapeutic outcomes.

CONCLUSIONS

Plasm ctDNA monitoring shows excellent clinical significance at the tested timepoints. Perioperative conversion of ctDNA status may indicate the therapeutic effect of radical surgery. Postoperative adjuvant therapy may be determined according to the ctDNA status.

TRAIL REGISTRATION

CRD42022304445.

Incidental detection of FGFR3 fusion via liquid biopsy leading to earlier diagnosis of urothelial carcinoma

The rising utilization of circulating tumor DNA (ctDNA) assays in Precision Oncology may incidentally detect genetic material from secondary sources. It is important that such findings are recognized and properly leveraged for both diagnosis and monitoring of response to treatment. Here, we report a patient in whom serial cell-free DNA (cfDNA) monitoring for his known prostate adenocarcinoma uncovered the emergence of an unexpected FGFR3-TACC3 gene fusion, a BRCA1 frameshift mutation, and other molecular abnormalities. Due to the rarity of FGFR3 fusions in prostate cancer, a workup for a second primary cancer was performed, leading to the diagnosis of an otherwise-asymptomatic urothelial carcinoma (UC). Once UC-directed treatment was initiated, the presence of these genetic abnormalities in cfDNA allowed for disease monitoring and early detection of resistance, well before radiographic progression. These findings also uncovered opportunities for targeted therapies against FGFR and BRCA1. Overall, this report highlights the multifaceted utility of longitudinal ctDNA monitoring in early cancer diagnosis, disease prognostication, therapeutic target identification, monitoring of treatment response, and early detection of emergence of resistance.

Immune checkpoint inhibitors in non-small cell lung cancer - When should we dare to stop treatment?

Over the last years, the emergence of immune checkpoint inhibitors (ICI) has revolutionized the treatment of non-small cell lung cancer (NSCLC). Patients in a palliative setting with previously very poor prognosis may now show remarkable responses over years. Yet, ICI therapy is very cost-intensive and involves frequent contacts with healthcare resources. Some of the early trial protocols restricted ICI treatment duration to two years. Now follow-up data of these studies is available and reveal the possibility of a persistent response after two or more years without further treatment for patients having successfully completed two years of therapy. May we now dare to think (and speak) of cure in the palliative setting? Does it mean we can stop ICI therapy after an initial two-year treatment? In this review, we try to improve confidence in clinical decision-making for this patient group. To this end, trials with a restricted treatment duration of two years and other data considering potential ICI discontinuation in responding patients were evaluated. Up to 25% of patients successfully complete an initial two-year course of ICI. Within this group about 40-46% of patients are alive at five years without further treatment with five-year survival rates of up to 83%. Data on ICI rechallenge are scarce, yet it does not seem to provide the same level of efficacy as at first exposure. At present there are no established biomarkers to help with decision-making. Possible future (bio-)markers, such as PD-L1, mutations, circulating tumor DNA (ctDNA) or Positron emission tomography (PET) need to be evaluated further in a prospective setting. In conclusion, we propose that the concept of discontinuing ICI therapy in patients with tumor response has to be seriously taken into consideration as it may be of benefit to our patients and health care systems.

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.

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

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

Minimal residual disease (MRD) detection in solid tumors using circulating tumor DNA: a systematic review

Minimal residual disease (MRD) refers to a very small number of residual tumor cells in the body during or after treatment, representing the persistence of the tumor and the possibility of clinical progress. Circulating tumor DNA (ctDNA) is a DNA fragment actively secreted by tumor cells or released into the circulatory system during the process of apoptosis or necrosis of tumor cells, which emerging as a non-invasive biomarker to dynamically monitor the therapeutic effect and prediction of recurrence. The feasibility of ctDNA as MRD detection and the revolution in ctDNA-based liquid biopsies provides a potential method for cancer monitoring. In this review, we summarized the main methods of ctDNA detection (PCR-based Sequencing and Next-Generation Sequencing) and their advantages and disadvantages. Additionally, we reviewed the significance of ctDNA analysis to guide the adjuvant therapy and predict the relapse of lung, breast and colon cancer et al. Finally, there are still many challenges of MRD detection, such as lack of standardization, false-negatives or false-positives results make misleading, and the requirement of validation using large independent cohorts to improve clinical outcomes.

Correlation analysis of MRD positivity in patients with completely resected stage I-IIIA non-small cell lung cancer: a cohort study

Background

The primary objective of this study is to thoroughly investigate the intricate correlation between postoperative molecular residual disease (MRD) status in individuals diagnosed with stage I-IIIA non-small cell lung cancer (NSCLC) and clinicopathological features, gene mutations, the tumour immune microenvironment and treatment effects.

Methods

The retrospective collection and analysis were carried out on the clinical data of ninety individuals diagnosed with stage I-IIIA NSCLC who underwent radical resection of lung cancer at our medical facility between January 2021 and March 2022. The comprehensive investigation encompassed an evaluation of multiple aspects including the MRD status, demographic information, clinicopathological characteristics, results from genetic testing, the tumor immune microenvironment, and treatment effects.

Results

No significant associations were observed between postoperative MRD status and variables such as gender, age, smoking history, pathological type, and gene mutations. However, a statistically significant correlation was found between MRD positivity and T (tumor diameter > 3 cm) as well as N (lymph node metastasis) stages (p values of 0.004 and 0.003, respectively). It was observed that higher proportions of micropapillary and solid pathological subtypes within lung adenocarcinoma were associated with increased rates of MRD-positivity after surgery (p = 0.007;0.005). MRD positivity demonstrated a correlation with the presence of vascular invasion (p = 0.0002). For the expression of programmed cell death ligand 1 (PD-L1), tumour positive score (TPS) ≥ 1% and combined positive score (CPS) ≥ 5 were correlated with postoperative MRD status (p value distribution was 0.0391 and 0.0153). In terms of ctDNA elimination, among patients identified as having postoperative MRD and lacking gene mutations, postoperative adjuvant targeted therapy demonstrated superiority over chemotherapy (p = 0.027).

Conclusion

Postoperative ctDNA-MRD status in NSCLC patients exhibits correlations with the size of the primary tumor, lymph node metastasis, pathological subtype of lung adenocarcinoma, presence of vascular invasion, as well as TPS and CPS values for PD-L1 expression; in postoperative patients with MRD, the effectiveness of adjuvant EGFR-TKI targeted therapy exceeds that of chemotherapy, as evidenced by the elimination of ctDNA.

Circulating tumor DNA minimal residual disease in clinical practice of non-small cell lung cancer

INTRODUCTION

The advance of diagnostics and treatments has greatly improved the prognosis of non-small cell lung cancer (NSCLC) patients. However, relapse and metastasis are still common problems encountered by NSCLC patients who have achieved complete remission. Therefore, overcoming the challenge of relapse and metastasis is particularly important for improving the prognosis of NSCLC patients. Research has shown that minimal residual disease (MRD) was a potential source of tumor relapse and metastasis, and circulating tumor DNA (ctDNA) MRD has obvious advantages in predicting the relapse and metastasis of NSCLC and evaluating treatment effectiveness. Therefore, dynamic monitoring of MRD is of great significance for NSCLC patient management strategies.

AREAS COVERED

We have reviewed articles related to NSCLC MRD included in PubMed and describes the biological significance and historical context of MRD research, reasons for using ctDNA to evaluate MRD, and potential value and challenges of ctDNA MRD in assessing relapse and metastasis of NSCLC, ultimately guiding clinical therapeutic strategies and management.

EXPERT OPINION

The standardized scope of ctDNA MRD detection for NSCLC requires more clinical research evidence to minimize study differences, making it possible to include in the clinical staging as a reliable indicator.

Prognostic value of postoperative ctDNA detection in patients with early non-small cell lung cancer: a systematic review and meta-analysis

Background

Circulating tumor DNA (ctDNA) has emerged as a potential biomarker for monitoring early non-small cell lung cancer (ENSCLC), particularly after radical surgery. However, the prognostic value of postoperative ctDNA is still being investigated due to the small sample size and heterogeneity of patients with ENSCLC in current trials. Moreover, the potential clinical utility of ctDNA assessment for administering adjuvant therapy (AT) in patients with ENSCLC is also an important area of active research.

Objectives

We aimed to identify the prognostic value of postoperative ctDNA detection in ENSCLC patients with stages I-III.

Design

This study type is a systematic review and meta-analysis.

Data sources and methods

We conducted a search in the Cochrane Library, Embase, PubMed, and ScienceDirect for prospective or retrospective investigations involving patients with ENSCLC, gathering outcomes based on predefined end points. The literature review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the Newcastle-Ottawa scale was employed to carry out a quality evaluation of the included studies. The primary end point of the study was to evaluate the association of ctDNA status in two time points (within 1 month after surgery and long-term postoperative monitoring with more than 3 months) with relapse-free survival (RFS) and overall survival (OS). In addition, the study investigated the role of ctDNA in predicting the response to AT. The secondary end points of the study were to determine the impact of ctDNA on RFS and OS in different subgroups of ENSCLC patients based on pathological subtypes and TNM staging.

Results

In total, 2149 studies were screened, and 11 studies met the inclusion criteria for the analysis. The presence of ctDNA within 1 month after surgery as well as long-term postoperative ctDNA were both associated with poorer RFS [hazard ratio (HR) = 4.43; 95% CI: 3.23-6.07 and HR = 7.99; 95% CI: 3.28-19.44, respectively] and worse OS (HR = 5.07; 95% CI: 2.80-9.19 and HR = 7.49; 95% CI: 3.42-16.43, respectively). Most subgroup analyses yielded similar results. Moreover, ctDNA-positive patients could acquire survival benefits from AT (HR = 0.30; 95% CI: 0.16-0.54), while ctDNA-negative patients that received AT did not show significant improvement in RFS (HR = 1.18; 95% CI: 0.67-2.09).

Conclusion

The postoperative ctDNA assessment is a promising approach to stratify the risk of relapse and death in ENSCLC patients. Our data suggest that patients with negative ctDNA in the postoperative setting may not benefit from AT, which warrants further investigation. This finding, if validated in prospective trials with a larger sample size, could aid in better-individualized treatment for patients and avoid potential side effects of AT.

Registration

This study was designed in accordance with PRISMA and registered with PROSPERO (CRD42022311615).

Accuracy of minimal residual disease detection by circulating tumor DNA profiling in lung cancer: a meta-analysis

BACKGROUND

The sensitivity and specificity of minimal residual disease detected by circulating tumor DNA profiling (ctDNA MRD) in lung cancer, with particular attention to the distinction between landmark strategy and surveillance strategy, for predicting relapse in lung cancer patients after definitive therapy has yet to be determined.

METHODS

The prognostic value of ctDNA MRD by landmark strategy and surveillance strategy was evaluated in a large cohort of patients with lung cancer who received definitive therapy using a systemic literature review and meta-analysis. Recurrence status stratified by ctDNA MRD result (positive or negative) was extracted as the clinical endpoint. We calculated the area under the summary receiver operating characteristic curves, and pooled sensitivities and specificities. Subgroup analyses were conducted based on histological type and stage of lung cancer, types of definitive therapy, and ctDNA MRD detection methods (detection technology and strategy such as tumor-informed or tumor-agnostic).

RESULTS

This systematic review and meta-analysis of 16 unique studies includes 1251 patients with lung cancer treated with definitive therapy. The specificity of ctDNA MRD in predicting recurrence is high (0.86-0.95) with moderate sensitivity (0.41-0.76), whether shortly after treatment or during the surveillance. The landmark strategy appears to be more specific but less sensitive than the surveillance strategy.

CONCLUSIONS

Our study suggests that ctDNA MRD is a relatively promising biomarker for relapse prediction among lung cancer patients after definitive therapy, with a high specificity but suboptimal sensitivity, whether in landmark strategy or surveillance strategy. Although surveillance ctDNA MRD analysis decreases specificity compared with the landmark strategy, the decrease is minimal compared to the increase in sensitivity for relapse prediction of lung cancer.

Multi-omics integrated circulating cell-free DNA genomic signatures enhanced the diagnostic performance of early-stage lung cancer and postoperative minimal residual disease

BACKGROUND

Liquid biopsy is a promising non-invasive alternative for cancer screening and minimal residual disease (MRD) detection, although there are some concerns regarding its clinical applications. We aimed to develop an accurate detection platform based on liquid biopsy for both cancer screening and MRD detection in patients with lung cancer (LC), which is also applicable to clinical use.

METHODS

We applied a modified whole-genome sequencing (WGS) -based High-performance Infrastructure For MultIomics (HIFI) method for LC screening and postoperative MRD detection by combining the hyper-co-methylated read approach and the circulating single-molecule amplification and resequencing technology (cSMART2.0).

FINDINGS

For early screening of LC, the LC score model was constructed using the support vector machine, which showed sensitivity (51.8%) at high specificity (96.3%) and achieved an AUC of 0.912 in the validation set prospectively enrolled from multiple centers. The screening model achieved detection efficiency with an AUC of 0.906 in patients with lung adenocarcinoma and outperformed other clinical models in solid nodule cohort. When applied the HIFI model to real social population, a negative predictive value (NPV) of 99.92% was achieved in Chinese population. Additionally, the MRD detection rate improved significantly by combining results from WGS and cSMART2.0, with sensitivity of 73.7% at specificity of 97.3%.

INTERPRETATION

In conclusion, the HIFI method is promising for diagnosis and postoperative monitoring of LC.

FUNDING

This study was supported by CAMS Innovation Fund for Medical Sciences, Chinese Academy of Medical Sciences, National Natural Science Foundation of China, Beijing Natural Science Foundation and Peking University People's Hospital.

Adjuvant therapies in stages I-III epidermal growth factor receptor-mutated lung cancer: current and future perspectives

Surgical resection followed by adjuvant cisplatin-based chemotherapy is the recommended treatment for patients with completely resected stage IB-IIIA non-small cell lung cancer (NSCLC). Even with the best management, recurrence is common and increases with disease stage (stage I: 26-45%; stage II: 42-62%; stage III: 70-77%). For patients with metastatic lung cancer and tumours that harbour epidermal growth factor receptor (EGFR) mutations, EGFR-tyrosine kinase inhibitors (TKIs) have improved survival. Their effectiveness in advanced stages of NSCLC raises the possibility that these agents may improve outcomes for patients with resectable EGFR-mutated lung cancer. In the ADAURA study, adjuvant osimertinib provided a significant improvement in disease-free survival (DFS) and reduced central nervous system (CNS) disease recurrence in patients with resected stage IB-IIIA EGFR-mutated NSCLC, with or without prior adjuvant chemotherapy. To reap the maximum benefits of EGFR-TKIs for patients with lung cancer, the early and rapid identification of EGFR mutations [and other oncogenic drivers, such as programmed cell death-ligand 1 (PD-L1), with matched targeted therapies] in diagnostic pathologic specimens has become essential. To ensure patients receive the most appropriate treatment, routine, comprehensive histological, immunohistochemical, and molecular analyses (with multiplex next generation sequencing) should be undertaken at the time of diagnosis. The potential for personalised treatments to cure more patients with early-stage lung cancer can only be realised if all therapies are considered when the care plan is formulated, by the multi-specialty experts managing patients. In this review, we discuss the progress and prospects for adjuvant treatments as part of a comprehensive plan of care for patients with resected stages I-III EGFR-mutated lung cancer, and explore how the field could go beyond DFS and overall survival to make cure a more frequent outcome of treatment in patients with resected EGFR-mutated lung cancer.

Longitudinal ctDNA profiling in precision oncology and immunο-oncology

Serial analysis of circulating tumor DNA (ctDNA) over the disease course is emerging as a prognostic, predictive and patient-monitoring biomarker. In the metastatic setting, several multigene ctDNA assays have been approved or recommended by regulatory organizations for personalized targeted therapy, especially for lung cancer. By contrast, in nonmetastatic disease, detection of ctDNA resulting from minimal residual disease (MRD) following multimodal treatment with curative intent presents major technical challenges. Several studies using tumor genotyping-informed serial ctDNA profiling have provided promising findings on the sensitivity and specificity of ctDNA in predicting the risk of recurrence. We discuss progress, limitations and future perspectives relating to the use of ctDNA as a biomarker to guide targeted therapy in metastatic disease, as well as the use of ctDNA MRD detection to guide adjuvant treatment in the nonmetastatic setting.

Tracking early lung cancer metastatic dissemination in TRACERx using ctDNA

Circulating tumour DNA (ctDNA) can be used to detect and profile residual tumour cells persisting after curative intent therapy1. The study of large patient cohorts incorporating longitudinal plasma sampling and extended follow-up is required to determine the role of ctDNA as a phylogenetic biomarker of relapse in early-stage non-small-cell lung cancer (NSCLC). Here we developed ctDNA methods tracking a median of 200 mutations identified in resected NSCLC tissue across 1,069 plasma samples collected from 197 patients enrolled in the TRACERx study2. A lack of preoperative ctDNA detection distinguished biologically indolent lung adenocarcinoma with good clinical outcome. Postoperative plasma analyses were interpreted within the context of standard-of-care radiological surveillance and administration of cytotoxic adjuvant therapy. Landmark analyses of plasma samples collected within 120 days after surgery revealed ctDNA detection in 25% of patients, including 49% of all patients who experienced clinical relapse; 3 to 6 monthly ctDNA surveillance identified impending disease relapse in an additional 20% of landmark-negative patients. We developed a bioinformatic tool (ECLIPSE) for non-invasive tracking of subclonal architecture at low ctDNA levels. ECLIPSE identified patients with polyclonal metastatic dissemination, which was associated with a poor clinical outcome. By measuring subclone cancer cell fractions in preoperative plasma, we found that subclones seeding future metastases were significantly more expanded compared with non-metastatic subclones. Our findings will support (neo)adjuvant trial advances and provide insights into the process of metastatic dissemination using low-ctDNA-level liquid biopsy.

Advances in liquid biopsy-based markers in NSCLC

Lung cancer is the second most-frequently occurring cancer and the leading cause of cancer-associated deaths worldwide. Non-small cell lung cancer (NSCLC), the most common type of lung cancer is often diagnosed in middle or advanced stages and have poor prognosis. Diagnosis of disease at an early stage is a key factor for improving prognosis and reducing mortality, whereas, the currently used diagnostic tools are not sufficiently sensitive for early-stage NSCLC. The emergence of liquid biopsy has ushered in a new era of diagnosis and management of cancers, including NSCLC, since analysis of circulating tumor-derived components, such as cell-free DNA (cfDNA), circulating tumor cells (CTCs), cell-free RNAs (cfRNAs), exosomes, tumor-educated platelets (TEPs), proteins, and metabolites in blood or other biofluids can enable early cancer detection, treatment selection, therapy monitoring and prognosis assessment. There have been great advances in liquid biopsy of NSCLC in the past few years. Hence, this chapter introduces the latest advances on the clinical application of cfDNA, CTCs, cfRNAs and exosomes, with a particular focus on their application as early markers in the diagnosis, treatment and prognosis of NSCLC.

Primary endpoints to assess the efficacy of novel therapeutic approaches in epidermal growth factor receptor-mutated, surgically resectable non-small cell lung cancer: A review

While the discovery of oncogenic driver mutations has personalized the metastatic non-small cell lung cancer (NSCLC) treatment landscape with effective targeted therapies, implementation of new treatments in resectable NSCLC has been limited due to the long follow-up needed for overall survival (OS). Until recently, treatment for patients with early-stage resectable NSCLC has been limited to perioperative chemotherapy, which provides modest benefits. However, the regulatory acceptance of two surrogate endpoints for OS has allowed recent approval of both adjuvant osimertinib and atezolizumab, providing patients with new treatment options to improve outcomes. In phase 3 oncology trials, OS has historically been viewed as the gold-standard efficacy measure, but disease-free survival and event-free survival (EFS) are now validated surrogate endpoints for OS in clinical trials and should be considered when mature OS data is unavailable. Another potential surrogate endpoint in the adjuvant NSCLC setting is circulating tumor DNA (ctDNA)-based minimal residual disease (MRD), although prospective validation is needed. For neoadjuvant targeted therapies, EFS, major pathologic response and ctDNA-based MRD are potential surrogate endpoints. To fully translate the success of the personalized treatment advances in the metastatic setting to earlier-stage disease, prospective validation studies of these potential surrogate endpoints that can accelerate the evaluation of drug efficacy are needed. A collaborative effort is also needed from all clinical and regulatory parties to collate surrogate endpoint data for large-scale validation. In this review we discuss the trends in surrogate endpoints used in oncology trials, with a focus on considerations for selecting appropriate primary endpoints in early-stage resectable EGFR-mutant NSCLC, an area of unmet need for novel treatment options.

Post nephrectomy management of localized renal cell carcinoma. From risk stratification to therapeutic evidence in an evolving clinical scenario

Standard treatment for localized non-metastatic renal cell carcinoma (RCC) is radical or partial nephrectomy. However, after radical surgery, patients with stage II-III have a substantial risk of relapse (around 35%). To date a unique standardized classification for the risk of disease recurrence still lack. Moreover, in the last years great attention has been focused in developing systemic therapies with the aim of improving the disease-free survival (DFS) of high-risk patients, with negative results from adjuvant VEGFR-TKIs. Therefore, there is still a need for developing effective treatments for radically resected RCC patients who are at intermediate/high risk of relapse. Recently, interesting results came from immune-checkpoint inhibitors (ICIs) targeting the PD-1/PD-L1 pathway, with a significant benefit in terms of disease-free survival from adjuvant pembrolizumab. However, the conflicting results of diverse clinical trials investigating different ICI-based regimens in the adjuvant setting, together with the still immature data on the overall survival advantage of immunotherapy, requires careful considerations. Furthermore, several questions remain unanswered, primarily regarding the selection of patients who could benefit the most from immunotherapy. In this review, we have summarized the main clinical trials investigating adjuvant therapy in RCC, with a particular focus on immunotherapy. Moreover, we have analyzed the crucial issue of patients' stratification according to the risk of disease recurrence, and we have described the possible future prospective and novel agents under evaluation for perioperative and adjuvant therapies.

Can Liquid Biopsy Based on ctDNA/cfDNA Replace Tissue Biopsy for the Precision Treatment of EGFR-Mutated NSCLC?

More and more clinical trials have explored the role of liquid biopsy in the diagnosis and treatment of EGFR-mutated NSCLC. In certain circumstances, liquid biopsy has unique advantages and offers a new way to detect therapeutic targets, analyze drug resistance mechanisms in advanced patients, and monitor MRD in patients with operable NSCLC. Although its potential cannot be ignored, more evidence is needed to support the transition from the research stage to clinical application. We reviewed the latest progress in research on the efficacy and resistance mechanisms of targeted therapy for advanced NSCLC patients with plasma ctDNA EGFR mutation and the evaluation of MRD based on ctDNA detection in perioperative and follow-up monitoring.

Progress and perspectives of perioperative immunotherapy in non-small cell lung cancer

Lung cancer is one of the leading causes of cancer-related death. Lung cancer mortality has decreased over the past decade, which is partly attributed to improved treatments. Curative surgery for patients with early-stage lung cancer is the standard of care, but not all surgical treatments have a good prognosis. Adjuvant and neoadjuvant chemotherapy are used to improve the prognosis of patients with resectable lung cancer. Immunotherapy, an epoch-defining treatment, has improved curative effects, prognosis, and tolerability compared with traditional and ordinary cytotoxic chemotherapy, providing new hope for patients with non-small cell lung cancer (NSCLC). Immunotherapy-related clinical trials have reported encouraging clinical outcomes in their exploration of different types of perioperative immunotherapy, from neoadjuvant immune checkpoint inhibitor (ICI) monotherapy, neoadjuvant immune-combination therapy (chemoimmunotherapy, immunotherapy plus antiangiogenic therapy, immunotherapy plus radiotherapy, or concurrent chemoradiotherapy), adjuvant immunotherapy, and neoadjuvant combined adjuvant immunotherapy. Phase 3 studies such as IMpower 010 and CheckMate 816 reported survival benefits of perioperative immunotherapy for operable patients. This review summarizes up-to-date clinical studies and analyzes the efficiency and feasibility of different neoadjuvant therapies and biomarkers to identify optimal types of perioperative immunotherapy for NSCLC.

Postoperative ctDNA detection predicts relapse but has limited effects in guiding adjuvant therapy in resectable stage I NSCLC

Background

To date, identifying resectable stage I non-small cell lung cancer (NSCLC) patients likely to benefit from adjuvant therapy (ADT) remains a major challenge. Previous studies suggest that circulating tumor DNA (ctDNA) is emerging as a promising biomarker for NSCLC. However, the effectiveness of ctDNA detection in guiding ADT for resectable stage I NSCLC patients remains elusive. This study aimed to elucidate the role of ctDNA detection in estimating prognosis and guiding ADT for resectable stage I NSCLC patients.

Methods

Individual patient data and ctDNA results data were collected from 270 patients across four independent cohorts. The detection of ctDNA was conducted at 3 days to 1 month after surgery. The endpoint for this study was relapse-free survival (RFS) and overall survival (OS).

Results

Of the 270 resectable stage I NSCLC patients, 9 patients with ctDNA-positive and 261 patients with ctDNA-negative. We found that the risk of recurrence was significantly lower in the ctDNA-negative group compared to the ctDNA-positive group(HR=0.11, p<0.0001). However, there is no difference in the risk of death between the two groups (p =0.39). In the ctDNA-positive group, there were no significant differences in RFS between patients who received ADT and patients who did not receive ADT (p =0.58). In the ctDNA-negative group, those who received ADT had a worse RFS in comparison with those who did not receive ADT (HR=2.36, p =0.029). No difference in OS was seen between patients who received ADT and patients who did not receive ADT in both the ctDNA-positive group and the ctDNA-negative group (All p values>0.05). Furthermore, there was no difference in RFS and OS between patients who received chemotherapy-based or tyrosine kinase inhibitor-based ADT and patients who did not receive ADT in both the ctDNA-positive group and the ctDNA-negative group (All p values>0.05).

Conclusions

Postoperative ctDNA detection can be a prognostic marker to predict recurrence but has limited effects in guiding ADT for resectable stage I NSCLC. Future prospective investigations are needed to verify these results.

Potential clinical utility of liquid biopsy in early-stage non-small cell lung cancer

BACKGROUND

Liquid biopsy has been widely researched for early diagnosis, prognostication and disease monitoring in lung cancer, but there is a need to investigate its clinical utility for early-stage non-small cell lung cancer (NSCLC).

METHODS

We performed a meta-analysis and systematic review to evaluate diagnostic and prognostic values of liquid biopsy for early-stage NSCLC, regarding the common biomarkers, circulating tumor cells, circulating tumor DNA (ctDNA), methylation signatures, and microRNAs. Cochrane Library, PubMed, EMBASE databases, ClinicalTrials.gov, and reference lists were searched for eligible studies since inception to 17 May 2022. Sensitivity, specificity and area under the curve (AUC) were assessed for diagnostic values. Hazard ratio (HR) with a 95% confidence interval (CI) was extracted from the recurrence-free survival (RFS) and overall survival (OS) plots for prognostic analysis. Also, potential predictive values and treatment response evaluation were further investigated.

RESULTS

In this meta-analysis, there were 34 studies eligible for diagnostic assessment and 21 for prognostic analysis. The estimated diagnostic values of biomarkers for early-stage NSCLC with AUCs ranged from 0.84 to 0.87. The factors TNM stage I, T1 stage, N0 stage, adenocarcinoma, young age, and nonsmoking contributed to a lower tumor burden, with a median cell-free DNA concentration of 8.64 ng/ml. For prognostic analysis, the presence of molecular residual disease (MRD) detection was a strong predictor of disease relapse (RFS, HR, 4.95; 95% CI, 3.06-8.02; p < 0.001) and inferior OS (HR, 3.93; 95% CI, 1.97-7.83; p < 0.001), with average lead time of 179 ± 74 days between molecular recurrence and radiographic progression. Predictive values analysis showed adjuvant therapy significantly benefited the RFS of MRD + patients (HR, 0.27; p < 0.001), while an opposite tendency was detected for MRD - patients (HR, 1.51; p = 0.19). For treatment response evaluation, a strong correlation between pathological response and ctDNA clearance was detected, and both were associated with longer survival after neoadjuvant therapy.

CONCLUSIONS

In conclusion, our study indicated liquid biopsy could reliably facilitate more precision and effective management of early-stage NSCLC. Improvement of liquid biopsy techniques and detection approaches and platforms is still needed, and higher-quality trials are required to provide more rigorous evidence prior to their routine clinical application.

Role of ctDNA for the detection of minimal residual disease in resected non-small cell lung cancer: a systematic review

Background

Operable stage I-III non-small cell lung cancer (NSCLC) has a high risk of recurrence, mainly due to remnant clones of the disease defined as minimal residual disease (MRD). Adjuvant chemotherapy has a limited efficacy in reducing the risk of relapse, and prognostic as well as predictive biomarkers in this context are currently missing.

Methods

We performed a systematic review to evaluate the state of the art about the role of circulating tumor DNA detection through liquid biopsy for the assessment of MRD in resected early-stage NSCLC patients.

Results

Among the 650 studies identified, 13 were eligible and included. Although highly heterogeneous, all the studies demonstrated a poor prognosis in patients with post-operative MRD, with a detection rate ranging from 6% to 45%. MRD detection preceded radiographic/clinical recurrence by a mean of 5.5 months. MRD positive patients were most likely to benefit from adjuvant treatment in terms of recurrence-free survival (RFS). Consistently, adjuvant therapy did not minimize the risk of relapse in the MRD negative group.

Conclusions

Liquid biopsy has a relevant role in assessing post-surgical MRD in resected NSCLC. Since currently there are no criteria other than stage and risk factors for the choice of adjuvant treatment in this setting, post-operative assessment of MRD through liquid biopsy might be a promising approach to guide the decision.

Predictive value of early kinetics of ctDNA combined with cfDNA and serum CEA for EGFR-TKI treatment in advanced non-small cell lung cancer

BACKGROUND

Circulating tumor DNA (ctDNA) has made a breakthrough as an early biomarker in operable early-stage cancer patients. However, the function of ctDNA combined with cell-free DNA (cfDNA) as a predictor in advanced non-small cell lung cancer (NSCLC) remains unknown. Here, we explored its potential as a biomarker for predicting the efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in patients with advanced NSCLC.

METHODS

A retrospective analysis was undertaken. Plasma collected from 51 patients with advanced NSCLC prior to and serially after starting treatment with EGFR-TKIs was analyzed by next-generation sequencing (NGS). The performance of ctDNA, cfDNA, and combining ctDNA with cfDNA were evaluated for their ability to predict survival outcomes.

RESULTS

Patients with early undetectable ctDNA and increasing cfDNA had a markedly better progression-free survival (PFS) (p < 0.001) and overall survival (OS) (p = 0.001) than those with early detectable ctDNA and decreasing cfDNA. Patients with early ctDNA clearance were more likely to have the ctDNA persistent clearance (p = 0.006). The early clearance rate of ctDNA in the normal carcinoembryonic antigen (CEA) group was significantly higher than in the low and high groups (p = 0.028). Patients with greater CEA decline had a higher early clearance rate of ctDNA than those with minor CEA change (p = 0.016).

CONCLUSIONS

We based this study on ctDNA and cfDNA, explored its prognostic predictive ability, and combined CEA to monitor EGFR-TKI efficacy. This study may provide new perspectives and insights into the precise treatment strategies for NSCLC patients.

Circulating tumor DNA-minimal residual disease: An up-and-coming nova in resectable non-small-cell lung cancer

Circulating tumor DNA (ctDNA) in the bloodstream can be used to reliably identify a minimal residual disease (MRD). ctDNA-MRD has demonstrated clinical values as a predictive and prognostic marker for resectable non-small cell lung cancer (NSCLC) regarding efficacy evaluation, recurrence monitoring, risk classification, and adjuvant treatment choices, and it has the advantage of being non-invasive, real-time, and dynamic. A recent large-scale prospective study of patients with resectable NSCLC revealed that patients with longitudinal undetectable MRD might represent a potentially curable population, benefiting many patients by eliminating wasteful therapies and side effects. However, there are still barriers to using ctDNA-MRD in clinical management, and the most significant is the lack of high-sensitivity detection technologies and consistent detection times. Herein, we defined the clinical significance of ctDNA-MRD in resectable NSCLC, summarized the available next-generation sequencing (NGS) detection approaches, and speculated on future clinical trial design and detection technology optimization.

Immunotherapy in unresectable stage III non-small-cell lung cancer: state of the art and novel therapeutic approaches

The standard of care for patients with stage III non-small-cell lung cancer (NSCLC) is concurrent chemoradiotherapy (CCRT) followed by 1 year of adjuvant durvalumab. Despite the survival benefit granted by immunotherapy in this setting, only 1/3 of patients are alive and disease free at 5 years. Novel treatment strategies are under development to improve patient outcomes in this setting: different anti-programmed cell death protein 1/programmed death-ligand 1 [anti-PD-(L)1] antibodies after CCRT, consolidation immunotherapy after sequential chemoradiotherapy, induction immunotherapy before CCRT and immunotherapy concurrent with CCRT and/or sequential chemoradiotherapy. Cross-trial comparison is particularly challenging in this setting due to the different timing of immunotherapy delivery and different patients' inclusion and exclusion criteria. In this review, we present the results of clinical trials investigating immune therapy in unresectable stage III NSCLC and discuss in-depth their biological rationale, their pitfalls and potential benefits. Particular emphasis is placed on the potential mechanisms of synergism between chemotherapy, radiation therapy and different monoclonal antibodies, and how this affects the tumor immune microenvironment. The designs and questions tackled by ongoing clinical trials are also discussed. Last, we address open questions and unmet clinical needs, such as the necessity for predictive biomarkers (e.g. radiomics and circulating tumor DNA). Identifying distinct subsets of patients to tailor anticancer treatment is a priority, especially in a heterogeneous disease such as stage III NSCLC.

Application of Non-Blood-Derived Fluid Biopsy in Monitoring Minimal Residual Diseases of Lung Cancer

Lung cancer is one of the most fatal malignant tumors in the world. Overcoming this disease is difficult due to its late diagnosis and relapse after treatment. Minimal residual disease (MRD) is described as the presence of free circulating tumor cells or other tumor cell derivatives in the biological fluid of patients without any clinical symptoms of cancer and negative imaging examination after the treatment of primary tumors. It has been widely discussed in the medical community as a bridge to solid tumor recurrence. Radiology, serology (carcinoembryonic antigen), and other clinical diagnosis and treatment methods widely used to monitor the progression of disease recurrence have obvious time-limited and -specific defects. Furthermore, as most samples of traditional liquid biopsies come from patients’ blood (including plasma and serum), the low concentration of tumor markers in blood samples limits the ability of these liquid biopsies in the early detection of cancer recurrence. The use of non-blood-derived fluid biopsy in monitoring the status of MRD and further improving the postoperative individualized treatment of patients with lung cancer is gradually ushering in the dawn of hope. This paper reviews the progress of several non-blood-derived fluid samples (urine, saliva, sputum, and pleural effusion) in detecting MRD in lung cancer as well as selecting the accurate treatment for it.

The Diagnostic Utility of Cell-Free DNA from Ex Vivo Bronchoalveolar Lavage Fluid in Lung Cancer

Simple Summary

This study aims to detect cell-free DNA released from lung cancer cells into the airway using the ex vivo BAL model of our own establishing. We finally demonstrated that cell-free DNA released from lung cancer cells is more abundant in the airway than in the blood, and the efficient collection of cell-free DNA derived from lung cancer in the airway by BAL and its genomic analysis could allow the accurate diagnosis of lung cancer. We believe that this approach will possibly make a breakthrough in the currently unsatisfactory diagnostic yield for lung cancer, since it is a new and constitutive diagnostic focusing on the gene mutations of lung cancer and their release into the airway in the form of cell-free DNA.

Abstract

Although bronchoscopy is generally performed to diagnose lung cancer, its diagnostic yield remains unsatisfactory. Assuming that lung cancer cells release cell-free DNA into the epithelial lining fluid, we hypothesized that lung cancer could be diagnosed by analyzing gene mutations in cell-free DNA in this fluid. This study included 32 patients with lung cancer who underwent surgery at our hospital. Bronchoalveolar lavage (BAL) was performed on the resected lung samples (ex vivo BAL model) after lobectomy. Each DNA sample (i.e., BAL fluid, primary lesion, and plasma) underwent deep targeted sequencing. Gene mutation analyses in the BAL fluid samples identified mutations identical to those in the primary lesions in 30 (93.8%) of 32 patients. In contrast, the microscopic cytology of the same BAL fluid samples yielded a diagnosis of lung cancer in only one of 32 patients, and the analysis of plasma samples revealed gene mutations identical to those in the primary lesions in only one of 32 patients. In conclusion, cell-free DNA released from lung cancer cells exists more abundantly in the airway than in the blood. The collection and analysis of the BAL fluid containing cell-free DNA derived from lung cancer can thus allow lung cancer diagnosis and the screening of driver mutations.

Updated Prognostic Factors in Localized NSCLC

Lung cancer is the most common cause of cancer mortality worldwide, and non-small cell lung cancer (NSCLC) represents 80% of lung cancer subtypes. Patients with localized non-small cell lung cancer may be considered for upfront surgical treatment. However, the overall 5-year survival rate is 59%. To improve survival, adjuvant chemotherapy (ACT) was largely explored and showed an overall benefit of survival at 5 years < 7%. The evaluation of recurrence risk and subsequent need for ACT is only based on tumor stage (TNM classification); however, more than 25% of patients with stage IA/B tumors will relapse. Recently, adjuvant targeted therapy has been approved for EGFR-mutated resected NSCLC and trials are evaluating other targeted therapies and immunotherapies in adjuvant settings. Costs, treatment duration, emergence of resistant clones and side effects stress the need for a better selection of patients. The identification and validation of prognostic and theranostic markers to better stratify patients who could benefit from adjuvant therapies are needed. In this review, we report current validated clinical, pathological and molecular prognosis biomarkers that influence outcome in resected NSCLC, and we also describe molecular biomarkers under evaluation that could be available in daily practice to drive ACT in resected NSCLC.

Prognostic Factors for Localized Clear Cell Renal Cell Carcinoma and Their Application in Adjuvant Therapy

Simple Summary

Approximately one fifth of patients with newly diagnosed renal cell carcinoma (RCC) present with metastatic disease and over one third of the remaining patients with localized RCC will eventually have metastases spread to distant sites after complete resection of the primary tumor in the kidney. Usually, disease recurrence is observed within the first five years of follow-up, but late recurrences after five years are seen in up to 10% of patients. Despite novel biomarkers, simple histopathological factors, such as tumor size, tumor grade, and tumor extension into the blood vessels or beyond the kidney, are still valid features in predicting the risk of disease recurrence after surgery. The optimal set of prognostic factors remains unclear. The results from ongoing placebo-controlled adjuvant therapy trials may elucidate prognostic features that help to define high-risk patients for disease recurrence.

Abstract

Approximately 20% of patients with renal cell carcinoma (RCC) present with primarily metastatic disease and over 30% of patients with localized RCC will develop distant metastases later, after complete resection of the primary tumor. Accurate postoperative prognostic models are essential for designing personalized surveillance programs, as well as for designing adjuvant therapy and trials. Several clinical and histopathological prognostic factors have been identified and adopted into prognostic algorithms to assess the individual risk for disease recurrence after radical or partial nephrectomy. However, the prediction accuracy of current prognostic models has been studied in retrospective patient cohorts and the optimal set of prognostic features remains unclear. In addition to traditional histopathological prognostic factors, novel biomarkers, such as gene expression profiles and circulating tumor DNA, are extensively studied to supplement existing prognostic algorithms to improve their prediction accuracy. Here, we aim to give an overview of existing prognostic features and prediction models for localized postoperative clear cell RCC and discuss their role in the adjuvant therapy trials. The results of ongoing placebo-controlled adjuvant therapy trials may elucidate prognostic factors and biomarkers that help to define patients at high risk for disease recurrence.

Update on adjuvant therapy in completely resected NSCLC patients

In patients with completely resected non‐small cell lung cancer (NSCLC), postoperative adjuvant chemotherapy has been associated with improvement in survival by minimizing the risk of recurrence. For years, systemic chemotherapy including platinum based regimen has been a mainstay treatment modality of adjuvant treatment after complete resection. ADAURA study showed that among completely resected IB to IIIA NSCLC, disease‐free survival was significantly better in patients under adjuvant osimertinib than a placebo group. After the advent of a variety of new treatment regimens, such as third generation TKI and immunotherapy, the landscape of postoperative adjuvant treatment has been changing. In this review, we discuss some key issues regarding choice of adjuvant treatment after complete resection in NSCLC, and provide further updates on recent advances in treatment modalities.

Detecting Liquid Remnants of Solid Tumors: Circulating Tumor DNA Minimal Residual Disease

Growing evidence demonstrates that circulating tumor DNA (ctDNA) minimal residual disease (MRD) following treatment for solid tumors predicts relapse. These results suggest that ctDNA MRD could identify candidates for adjuvant therapy and measure response to such treatment. Importantly, factors such as assay type, amount of ctDNA release, and technical and biological background can affect ctDNA MRD results. Furthermore, the clinical utility of ctDNA MRD for treatment personalization remains to be fully established. Here, we review the evidence supporting the value of ctDNA MRD in solid cancers and highlight key considerations in the application of this potentially transformative biomarker.

SIGNIFICANCE

ctDNA analysis enables detection of MRD and predicts relapse after definitive treatment for solid cancers, thereby promising to revolutionize personalization of adjuvant and consolidation therapies.

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

Circulating tumor DNA (ctDNA) is cell-free DNA (cfDNA) fragment in the bloodstream that originates from malignant tumors or circulating tumor cells. Recently, ctDNA has emerged as a promising non-invasive biomarker in clinical oncology. Analysis of ctDNA opens up new avenues for individualized cancer diagnosis and therapy in various types of tumors. Evidence suggests that minimum residual disease (MRD) is closely associated with disease recurrence, thus identifying specific genetic and molecular alterations as novel MRD detection targets using ctDNA has been a research focus. MRD is considered a promising prognostic marker to identify individuals at increased risk of recurrence and who may benefit from treatment. This review summarizes the current knowledge of ctDNA and MRD in solid tumors, focusing on the potential clinical applications and challenges. We describe the current state of ctDNA detection methods and the milestones of ctDNA development and discuss how ctDNA analysis may be an alternative for tissue biopsy. Additionally, we evaluate the clinical utility of ctDNA analysis in solid tumors, such as recurrence risk assessment, monitoring response, and resistance mechanism analysis. MRD detection aids in assessing treatment response, patient prognosis, and risk of recurrence. Moreover, this review highlights current advancements in utilizing ctDNA to monitor the MRD of solid tumors such as lung cancer, breast cancer, and colon cancer. Overall, the clinical application of ctDNA-based MRD detection can assist clinical decision-making and improve patient outcomes in malignant tumors.

The Role and Impact of Minimal Residual Disease in NSCLC

Purpose of Review

There has been a huge development in the assessment of malignancies through liquid biopsies last years, especially for NSCLC, where its use has become part of clinical practice in some settings. We aim to summarize current evidence about minimal residual disease and its use in lung cancer.

Recent Findings

Recent studies using ctDNA in NSCLC but also in other types of cancer found strong correlations between the presence of ctDNA and the risk of disease progression or death after curative intent, despite current technical difficulties in performing this analysis (high sensitivity and specificity required).

Summary

Evaluation of MRD in NSCLC, especially through ctDNA, could be an important point in future trial designs and could permit a more “targeted” adjuvant treatment.

Liquid Biopsy to Detect Minimal Residual Disease: Methodology and Impact

One reason why some patients experience recurrent disease after a curative-intent treatment might be the persistence of residual tumor cells, called minimal residual disease (MRD). MRD cannot be identified by standard radiological exams or clinical evaluation. Tumor-specific alterations found in the blood indirectly diagnose the presence of MRD. Liquid biopsies thus have the potential to detect MRD, allowing, among other things, the detection of circulating tumor DNA (ctDNA), circulating tumor cells (CTC), or tumor-specific microRNA. Although liquid biopsy is increasingly studied, several technical issues still limit its clinical applicability: low sensitivity, poor standardization or reproducibility, and lack of randomized trials demonstrating its clinical benefit. Being able to detect MRD could give clinicians a more comprehensive view of the risk of relapse of their patients and could select patients requiring treatment escalation with the goal of improving cancer survival. In this review, we are discussing the different methodologies used and investigated to detect MRD in solid cancers, their respective potentials and issues, and the clinical impacts that MRD detection will have on the management of cancer patients.

Potential utility of longitudinal somatic mutation and methylation profiling for predicting molecular residual disease in postoperative non-small cell lung cancer patients

GROWING EFFORTS ARE BEING INVESTED IN INVESTIGATING VARIOUS MOLECULAR APPROACHES TO DETECT MINIMAL RESIDUAL DISEASE (MRD) AND PREDICT DISEASE RECURRENCE. IN OUR STUDY, WE INVESTIGATED THE UTILITY OF PARALLEL LONGITUDINAL ANALYSIS OF MUTATION AND DNA METHYLATION PROFILES FOR PREDICTING MRD IN POSTOPERATIVE NON-SMALL-CELL LUNG CANCER (NSCLC) PATIENTS. TUMOR TISSUES AND LONGITUDINAL BLOOD SAMPLES WERE OBTAINED FROM 65 PATIENTS WITH RESECTED STAGE IA-IIIB NSCLC. SOMATIC MUTATION AND DNA METHYLATION PROFILING WERE PERFORMED USING ULTRA-DEEP TARGETED SEQUENCING AND TARGETED BISULFITE SEQUENCING, RESPECTIVELY. DYNAMIC CHANGES IN PLASMA-BASED MUTATION AND TUMOR-INFORMED METHYLATION PROFILES, REFLECTED AS MRD SCORE, WERE OBSERVED FROM BEFORE SURGERY (BASELINE) TO POSTOPERATIVE FOLLOW-UP, REFLECTING THE DECREASE IN TUMOR BURDEN OF THE PATIENTS WITH RESECTED NSCLC. MUTATIONS WERE DETECTED FROM PLASMA SAMPLES IN 63% OF THE PATIENTS AT BASELINE, WHICH SIGNIFICANTLY REDUCED TO 23-25% DURING POST-OPERATIVE FOLLOW-UPS. MRD SCORE POSITIVE RATE WAS 95.7% AT BASELINE, WHICH REDUCED TO 74% AT THE FIRST AND 70% AT THE SECOND FOLLOW-UP. AMONG THE 5 RELAPSED PATIENTS WITH PARALLEL LONGITUDINAL ANALYSIS OF MUTATION AND METHYLATION PROFILE, ELEVATED MRD SCORE WAS OBSERVED AT FOLLOW-UP BETWEEN 0.5-7 MONTHS PRIOR TO RADIOLOGIC RECURRENCE FOR ALL 5 PATIENTS. OF THEM, 4 PATIENTS ALSO HAD CONCOMITANT INCREASE IN ALLELIC FRACTION OF MUTATIONS IN AT LEAST 1 FOLLOW-UP TIME POINT, BUT ONE PATIENT HAD NO MUTATION DETECTED THROUGHOUT ALL FOLLOW-UPS. OUR RESULTS DEMONSTRATE THAT LONGITUDINAL PROFILING OF MUTATION AND DNA METHYLATION MAY HAVE POTENTIAL FOR DETECTING MRD AND PREDICTING RECURRENCE IN POSTOPERATIVE NSCLC PATIENTS.

Early assessment of circulating tumor DNA after curative-intent resection predicts tumor recurrence in early-stage and locally advanced non-small-cell lung cancer

Circulating tumor DNA (ctDNA) has demonstrated great potential as a noninvasive biomarker to assess minimal residual disease (MRD) and profile tumor genotypes in patients with non‐small‐cell lung cancer (NSCLC). However, little is known about its dynamics during and after tumor resection, or its potential for predicting clinical outcomes. Here, we applied a targeted‐capture high‐throughput sequencing approach to profile ctDNA at various disease milestones and assessed its predictive value in patients with early‐stage and locally advanced NSCLC. We prospectively enrolled 33 consecutive patients with stage IA to IIIB NSCLC undergoing curative‐intent tumor resection (median follow‐up: 26.2 months). From 21 patients, we serially collected 96 plasma samples before surgery, during surgery, 1–2 weeks postsurgery, and during follow‐up. Deep next‐generation sequencing using unique molecular identifiers was performed to identify and quantify tumor‐specific mutations in ctDNA. Twelve patients (57%) had detectable mutations in ctDNA before tumor resection. Both ctDNA detection rates and ctDNA concentrations were significantly higher in plasma obtained during surgery compared with presurgical specimens (57% versus 19% ctDNA detection rate, and 12.47 versus 6.64 ng·mL⁻¹, respectively). Four patients (19%) remained ctDNA‐positive at 1–2 weeks after surgery, with all of them (100%) experiencing disease progression at later time points. In contrast, only 4 out of 12 ctDNA‐negative patients (33%) after surgery experienced relapse during follow‐up. Positive ctDNA in early postoperative plasma samples was associated with shorter progression‐free survival (P = 0.013) and overall survival (P = 0.004). Our findings suggest that, in early‐stage and locally advanced NSCLC, intraoperative plasma sampling results in high ctDNA detection rates and that ctDNA positivity early after resection identifies patients at risk for relapse.

Liquid Biopsy-Based Biosensors for MRD Detection and Treatment Monitoring in Non-Small Cell Lung Cancer (NSCLC)

Globally, non-small cell lung cancer (NSCLC) is the leading cause of cancer deaths. Despite advancements in chemotherapy and targeted therapies, the 5-year survival rate has remained at 16% for the past forty years. Minimal residual disease (MRD) is described as the existence of either isolated tumour cells or circulating tumour cells in biological liquid of patients after removal of the primary tumour without any clinical signs of cancer. Recently, liquid biopsy has been promising as a non-invasive method of disease monitoring and treatment guidelines as an MRD marker. Liquid biopsy could be used to detect and assess earlier stages of NSCLC, post-treatment MRD, resistance to targeted therapies, immune checkpoint inhibitors (ICIs) and tumour mutational burden. MRD surveillance has been proposed as a potential marker for lung cancer relapse. Principally, biosensors provide the quantitative analysis of various materials by converting biological functions into quantifiable signals. Biosensors are usually operated to detect antibodies, enzymes, DNA, RNA, extracellular vesicles (EVs) and whole cells. Here, we present a category of biosensors based on the signal transduction method for identifying biosensor-based biomarkers in liquid biopsy specimens to monitor lung cancer treatment.

Associations between tumor mutations in cfDNA and survival in non-small cell lung cancer

INTRODUCTION

Studies have indicated that detection of mutated KRAS or EGFR in circulating tumor DNA (ctDNA) from pre-treatment plasma samples is a negative prognostic factor for non-small cell lung cancer (NSCLC) patients. This study aims to investigate whether this is the case also for NSCLC patients with other tumor mutations.

METHODS

Tumor tissue DNA from 107 NSCLC patients was sequenced and corresponding pre-treatment plasma samples were analyzed using a limited target next-generation sequencing approach validated in this study. Patients without detected mutations in tumor samples were excluded from further analyses.

RESULTS

Mutations were detected in tumor samples from 71 patients. Median age was 68 years, 51% were female, and 88% were current/former smokers, 91% had adenocarcinoma, 4% had squamous cell carcinoma and 6% had other NSCLC. The distribution between stage I, II, III and IV was 33%, 8%, 30%, and 29%, respectively. Between one and three tumor mutation(s) were detected in ctDNA from corresponding plasma samples. Patients with detected ctDNA had shorter PFS (9.6 vs. 41.3 months, HR: 2.9, 95% CI: 1.6-5.2, p = 0.0003) and OS (13.6 vs. 115.0 months, HR: 4.0, 95% CI: 2.1-7.6, p = 0.00002) than patients without detected ctDNA. ctDNA remained a significant negative prognostic factor for OS (HR: 2.5, 95% CI: 1.1-5.7, p=0.0327), but not PFS, in the multivariable analyses adjusting for baseline patient and disease characteristics including stage of disease.

CONCLUSIONS

This study adds further evidence supporting that detectable tumor mutations in cfDNA is associated with a worse prognosis in NSCLC harboring a variety of tumor mutations.

EGFR Status Assessment for Better Care of Early Stage Non-Small Cell Lung Carcinoma: What Is Changing in the Daily Practice of Pathologists?

The recent emergence of novel neoadjuvant and/or adjuvant therapies for early stage (I-IIIA) non-small cell lung carcinoma (NSCLC), mainly tyrosine kinase inhibitors (TKIs) targeting EGFR mutations and immunotherapy or chemo-immunotherapy, has suddenly required the evaluation of biomarkers predictive of the efficacy of different treatments in these patients. Currently, the choice of one or another of these treatments mainly depends on the results of immunohistochemistry for PD-L1 and of the status of EGFR and ALK. This new development has led to the setup of different analyses for clinical and molecular pathology laboratories, which have had to rapidly integrate a number of new challenges into daily practice and to establish new organization for decision making. This review outlines the impact of the management of biological samples in laboratories and discusses perspectives for pathologists within the framework of EGFR TKIs in early stage NSCLC.

The Landscape of Cell-Free HBV Integrations and Mutations in Cirrhosis and Hepatocellular Carcinoma Patients

PURPOSE

Intratumoral hepatitis B virus (HBV) integrations and mutations are related to hepatocellular carcinoma (HCC) progression. Circulating cell-free DNA (cfDNA) has shown itself as a powerful noninvasive biomarker for cancer. However, the HBV integration and mutation landscape on cfDNA remains unclear.

EXPERIMENTAL DESIGN

A cSMART (Circulating Single-Molecule Amplification and Resequencing Technology)-based method (SIM) was developed to simultaneously investigate HBV integration and mutation landscapes on cfDNA with HBV-specific primers covering the whole HBV genome. Patients with HCC (n = 481) and liver cirrhosis (LC; n = 517) were recruited in the study.

RESULTS

A total of 6,861 integration breakpoints including TERT and KMT2B were discovered in HCC cfDNA, more than in LC. The concentration of circulating tumor DNA (ctDNA) was positively correlated with the detection rate of these integration hotspots and total HBV integration events in cfDNA. To track the origin of HBV integrations in cfDNA, whole-genome sequencing (WGS) was performed on their paired tumor tissues. The paired comparison of WGS data from tumor tissues and SIM data from cfDNA confirmed most recurrent integration events in cfDNA originated from tumor tissue. The mutational landscape across the whole HBV genome was first generated for both HBV genotype C and B. A region from nt1100 to nt1500 containing multiple HCC risk mutation sites (OR > 1) was identified as a potential HCC-related mutational hot zone.

CONCLUSIONS

Our study provides an in-depth delineation of HBV integration/mutation landscapes at cfDNA level and did a comparative analysis with their paired tissues. These findings shed light on the possibilities of noninvasive detection of virus insertion/mutation.

Neoadjuvant immunotherapy for non-small cell lung cancer: State of the art

Lung cancer mortality has decreased over the past decade and can be partly attributed to advances in targeted therapy and immunotherapy. Immune checkpoint inhibitors (ICIs) have rapidly evolved from investigational drugs to standard of care for the treatment of metastatic non-small cell lung cancer (NSCLC). In particular, antibodies that block inhibitory immune checkpoints, such as programmed cell death protein 1 (PD-1) and programmed cell death 1 ligand 1 (PD-L1), have revolutionized the treatment of advanced NSCLC, when administered alone or in combination with chemotherapy. Immunotherapy is associated with higher response rates, improved overall survival (OS), and increased tolerability compared with conventional cytotoxic chemotherapy. These benefits may increase the utility of immunotherapy and its combinational use with chemotherapy in the neoadjuvant treatment of patients with NSCLC. Early findings from various ongoing clinical trials suggest that neoadjuvant ICIs alone or combined with chemotherapy may significantly reduce systemic recurrence and improve long-term OS or cure rates in resectable NSCLC. Here we further summarize the safety and efficacy of various neoadjuvant treatment regimens including immunotherapy from ongoing clinical trials and elaborate the role of neoadjuvant immunotherapy in patients with resectable NSCLC. In addition, we discuss several unresolved challenges, including the evaluations to assess neoadjuvant immunotherapy response, the role of adjuvant treatment after neoadjuvant immunotherapy, the efficacy of treatment for oncogenic-addicted tumors, and predictive biomarkers. We also provide our perspective on ways to overcome current obstacles and establish neoadjuvant immunotherapy as a standard of care.