Deep sequencing of circulating tumor DNA detects molecular residual disease and predicts recurrence in gastric cancer

Correlation of the treatment sensitivity of patient-derived organoids with treatment outcomes in patients with head and neck cancer (SOTO): protocol for a prospective observational study

INTRODUCTION

Organoids have been successfully used in several areas of cancer research and large living biobanks of patient-derived organoids (PDOs) have been developed from various malignancies. The characteristics of the original tumour tissue such as mutation signatures, phenotype and genetic diversity are well preserved in organoids, thus showing promising results for the use of this model in translational research. In this study, we aim to assess whether we can generate PDOs from head and neck squamous cell carcinoma (HNSCC) samples and whether PDOs can be used to predict treatment sensitivity in HNSCC patients as well as to explore potential biomarkers.

METHODS AND ANALYSIS

This is a prospective observational study at a single centre (Guy's and St Thomas' NHS Foundation Trust) to generate PDOs from patients' samples to assess treatment response and to correlate with patients' treatment outcomes. Patients will be included if they are diagnosed with HNSCC undergoing curative treatment (primary surgery or radiotherapy) or presenting with recurrent or metastatic cancers and they will be categorised into three groups (cohort 1: primary surgery, cohort 2: primary radiotherapy and cohort 3: recurrent/metastatic disease). Research tumour samples will be collected and processed into PDOs and chemosensitivity/radiosensitivity will be assessed using established methods. Moreover, blood and other biological samples (eg, saliva) will be collected at different time intervals during treatment and will be processed in the laboratory for plasma and peripheral blood mononuclear cell (PBMC) isolation. Plasma and saliva will be used for circulating tumour DNA analysis and PBMC will be stored for assessment of the peripheral immune characteristics of the patients as well as to perform co-culture experiments with PDOs. SOTO study (correlation of the treatment Sensitivity of patient-derived Organoids with Treatment Outcomes in patients with head and neck cancer) uses the collaboration of several specialties in head and neck cancer and has the potential to explore multiple areas of research with the aim of offering a valid and effective approach to personalised medicine for cancer patients.

ETHICS AND DISSEMINATION

This study was approved by North West-Greater Manchester South Research Ethics Committee (REC Ref: 22/NW/0023) on 21 March 2022. An informed consent will be obtained from all participants prior to inclusion in the study. Results will be disseminated via peer-reviewed publications and presentations at international conferences.

TRIAL REGISTRATION NUMBER

NCT05400239.

Circulating tumor DNA predicts recurrence and survival in patients with resectable gastric and gastroesophageal junction cancer

BACKGROUND

Gastric and gastroesophageal junction (GEJ) cancer represents a significant global health challenge, with high recurrence rates and poor survival outcomes. This study investigates circulating tumor DNA (ctDNA) as a biomarker for assessing recurrence risk in patients with resectable gastric and GEJ adenocarcinomas (AC).

METHODS

Patients with resectable gastric and GEJ AC, undergoing perioperative chemotherapy and surgery, were prospectively enrolled. Serial plasma samples were collected at baseline, after one cycle of chemotherapy, after preoperative chemotherapy, and after surgery. ctDNA was assessed by a ddPCR test (TriMeth), which targets the gastrointestinal cancer-specific methylation patterns of the genes C9orf50, KCNQ5, and CLIP4.

RESULTS

ctDNA analysis was performed on 229 plasma samples from 86 patients. At baseline, ctDNA was detected in 56% of patients, which decreased to 37% following one cycle of chemotherapy, 25% after preoperative chemotherapy and 15% after surgical resection. The presence of ctDNA after one cycle of chemotherapy was associated with reduced recurrence-free survival (RFS) (HR = 2.54, 95% confidence interval (CI) 1.33-4.85, p = 0.005) and overall survival (OS) (HR = 2.23, 95% CI 1.07-4.62, p = 0.032). Similarly, ctDNA after surgery was associated with significantly shorter RFS (HR = 6.22, 95% CI 2.39-16.2, p < 0.001) and OS (HR = 6.37, 95% CI 2.10-19.3, p = 0.001). Multivariable regression analysis confirmed ctDNA after surgery as an independent prognostic factor (p < 0.001).

CONCLUSION

ctDNA analysis has the potential to identify patients at elevated risk of recurrence, thus providing personalized treatment strategies for patients with resectable gastric and GEJ cancer. Further validation in larger cohorts and ctDNA-guided interventions are needed for future clinical use.

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.

The Overlooked Cornerstone in Precise Medicine: Personalized Postoperative Surveillance Plan for NSCLC

Non-small cell lung cancer recurrence after curative-intent surgery remains a challenge despite advancements in treatment. We review postoperative surveillance strategies and their impact on overall survival, highlighting recommendations from clinical guidelines and controversies. Studies suggest no clear benefit from more intensive imaging, whereas computed tomography scans reveal promise in detecting recurrence. For early-stage disease, including ground-glass opacities and adenocarcinoma in situ or minimally invasive adenocarcinoma, less frequent surveillance may suffice owing to favorable prognosis. Liquid biopsy, especially circulating tumor deoxyribonucleic acid, holds potential for detecting minimal residual disease. Clinicopathologic factors and genomic profiles can also provide information about site-specific metastases. Machine learning may enable personalized surveillance plans on the basis of multi-omics data. Although precision medicine transforms non-small cell lung cancer treatment, optimizing surveillance strategies remains essential. Tailored surveillance strategies and emerging technologies may enhance early detection and improve patients' survival, necessitating further research for evidence-based protocols.

Mutational and transcriptional profile predicts the prognosis of stage IV gastric cancer - Prognostic factors for metastatic gastric cancer

BACKGROUND AND STUDY AIMS

The clinicopathological risk factors in the prognosis of stage IV gastric cancer have been comprehensively studied. However, the influencing factors of stage IV gastric cancer prognosis at genomic and transcriptional levels have not been well defined.

PATIENTS AND METHODS

The mutational and transcriptional data, along with demographic, clinicopathological and prognostic information of 44 stage IV gastric cancer patients were downloaded from the TCGA database. Univariate and multivariate analyses were performed to identify the significant risk factors and a Nomogram model was established to predict the patient prognosis.

RESULTS

TTN, TP53, FLG, LRP1B, SYNE1 and ARID1A were among the top mutated genes without hot-spot mutations. The mutational status of AHNAK2, ASCC3, DNAH3, DOP1A, MYLK, SIPA1L1, SORBS2, SYNE1 and ANF462 significantly stratified the patient prognosis. The transcription of several genes, such as AQP10, HOXC8/9/10, COL10A1/COL11A1, WNT7B, KRT17 and KLK6 was significantly up-regulated or down-regulated. Enrichment analysis on mutations and transcription revealed cell skeleton and membrane function, extracellular matrix function, HPV infection, and several cancer-related pathways as the main aberrancies. Univariate analyses revealed a series of significant factors stratifying patient prognosis, mainly including cancer location, several mutated genes and many up- or down-regulated genes. However, subsequent multivariate analysis revealed SYNE1 mutation, DNAH3 mutation, COMMD3 transcription level, and cancer location as the independent risk factors. A Nomogram model has been established with these significant risk factors to predict the patient prognosis. Further validation is needed to ensure the effectiveness of the model in real clinical practice.

CONCLUSIONS

Cancer location, along with the mutational status of SYNE1 and DNAH3 and the transcriptional level of COMMD3 were independent risk factors of stage IV gastric cancer. A Nomogram model was established with these factors for prognosis prediction.

Circulating miRNA and circulating tumor DNA application as liquid biopsy markers in gastric cancer

Liquid biopsy has been investigated as a novel method to overcome the numerous challenges in gastric cancer (GC) management. This non-invasive, feasible, and easy-to-repeat method has been shown to be cost-effective and capable of increasing diagnostic sensitivity and prognostic assessment. Additionally, it is potentially accurate to aid decision-making and personalized treatment planning. MicroRNA (miRNA) and circulating tumor DNA (ctDNA) markers can enhance GC management in various aspects, including diagnosis (mainly earlier diagnosis and the ability to perform population-based screening), prognosis (more precise stratification of prognosis), and treatment (including more accurate prediction of treatment response and earlier detection of resistance to the treatment). Concerning the treatment-related application, miRNAs' mimics and antagonists (by using two main strategies of restoring tumor suppressor miRNAs and inhibiting oncogene miRNAs) have been shown to be effective therapeutic agents. However, these need to be further validated in clinical trials. Furthermore, novel delivery systems, such as lipid-based vectors, polymeric-based vectors, and exosome-based delivery, have been developed to enhance the performance of these agents. Moreover, this paper explores the current detection and measuring methods for these markers. These approaches are categorized into direct methods (e.g., Chem-NAT, HTG EdgeSeq, and Multiplex Circulating Fireplex) and indirect methods (e.g., Reverse transcription-quantitative polymerase chain reaction (RT-qPCR), qPCR, microarray, and NGS) for miRNA detection. For ctDNA measurement, main core technologies like NGS, digital PCR, real-time PCR, and mass spectrometry are suggested.

Updates in Translational Science for Esophageal and Gastric Cancers

In this article, the authors summarize the current state of translational science for esophageal and gastric cancers. The available targeted therapies, immunotherapies, and recently discovered molecular targets are reviewed. The authors introduce circulating tumor deoxyribonucleic acid and its promise as a biomarker to detect disease recurrence. The authors present patient-derived organoids as a new model for studying carcinogenesis and treatment responses. Finally, we discuss the implications of organoid models for precision oncology and describe exciting new work applying gene editing technology to organoids and studying tumor-microenvironment interactions using 3-dimensional co-culture systems.

Development and validation of a circulating tumor DNA-based optimization-prediction model for short-term postoperative recurrence of endometrial cancer

BACKGROUND

Endometrial cancer (EC) is a common gynecological malignancy that typically requires prompt surgical intervention; however, the advantage of surgical management is limited by the high postoperative recurrence rates and adverse outcomes. Previous studies have highlighted the prognostic potential of circulating tumor DNA (ctDNA) monitoring for minimal residual disease in patients with EC.

AIM

To develop and validate an optimized ctDNA-based model for predicting short-term postoperative EC recurrence.

METHODS

We retrospectively analyzed 294 EC patients treated surgically from 2015-2019 to devise a short-term recurrence prediction model, which was validated on 143 EC patients operated between 2020 and 2021. Prognostic factors were identified using univariate Cox, Lasso, and multivariate Cox regressions. A nomogram was created to predict the 1, 1.5, and 2-year recurrence-free survival (RFS). Model performance was assessed via receiver operating characteristic (ROC), calibration, and decision curve analyses (DCA), leading to a recurrence risk stratification system.

RESULTS

Based on the regression analysis and the nomogram created, patients with postoperative ctDNA-negativity, postoperative carcinoembryonic antigen 125 (CA125) levels of < 19 U/mL, and grade G1 tumors had improved RFS after surgery. The nomogram's efficacy for recurrence prediction was confirmed through ROC analysis, calibration curves, and DCA methods, highlighting its high accuracy and clinical utility. Furthermore, using the nomogram, the patients were successfully classified into three risk subgroups.

CONCLUSION

The nomogram accurately predicted RFS after EC surgery at 1, 1.5, and 2 years. This model will help clinicians personalize treatments, stratify risks, and enhance clinical outcomes for patients with EC.

A predictive nomogram developed and validated for gastric cancer patients with triple-negative tumor markers

Aim: To predict the prognosis of gastric cancer patients with triple-negative tumor markers. Materials & methods: Prognostic factors of the nomogram were identified through univariate and multivariate Cox regression analyses. Calibration and receiver operating characteristic curves were used to assess accuracy. Decision curve analysis and concordance indexes were utilized to compare the nomogram with the pathological tumor, node, metastasis stage. Results: A nomogram incorporating log odds of positive lymph nodes, tumor size and lymphocyte-to-monocyte ratio was constructed. The calibration and receiver operating characteristic curves (area under the curve >0.85) showed high accuracy in predicting overall survival. The concordance indexes (0.832 vs 0.760; p < 0.001) and decision curve analysis demonstrated that the nomogram was superior to the pathological tumor, node, metastasis stage. Conclusion: A prediction and risk stratification nomogram has been developed and validated for gastric cancer patients with triple-negative tumor markers.

Circulating tumour DNA-Based molecular residual disease detection in resectable cancers: a systematic review and meta-analysis

BACKGROUND

Circulating tumour DNA (ctDNA)-based molecular residual disease (MRD) detection technology has been widely used for recurrence evaluation, but there is no agreement on the efficacy of assessing recurrence and overall survival (OS) prognosis, as well as the sensitivity and specificity of landmark detection and longitudinal detection.

METHODS

We systematically searched Pubmed, Embase, Cochrane, and Scopus for prospective studies or randomized controlled trials that collected blood samples prospectively. The search period was from Jan 1, 2013, to Sept 10, 2023. We excluded retrospective studies. The primary endpoint was to assess the hazard ratio (HR) between circulating tumour DNA positive (ctDNA+) and negative (ctDNA-) for recurrence-free survival incidence (RFS), disease-free survival (DFS), progression-free survival (PFS), event-free survival (EFS), time to recurrence (TTR), distant metastasis-free survival (DMFS) or OS in patients with resectable cancers. We calculated the pooled HR of recurrence and OS and 95% confidence interval (CI) in patients with resected cancers using a random-effects model. Pooled sensitivity and specificity were estimated using the bivariate random effects model.

FINDINGS

This systematic review and meta-analysis returned 7578 records, yielding 80 included studies after exclusion. We found that the HR of recurrence across all included cancers between patients with ctDNA+ and ctDNA- was 7.48 (95% CI 6.39-8.77), and the OS was 5.58 (95% CI 4.17-7.48). We also found that the sensitivity, area under the summary receiver operating characteristic curve (AUSROC) and diagnostic odds ratio (DOR) of longitudinal tests were higher than that of landmark tests between patients with ctDNA+ and ctDNA- (0.74, 95% CI 0.68-0.80 vs 0.50, 95% CI 0.46-0.55; 0.88 vs. 0.80; 25.70, 95% CI 13.20-45.40 vs. 9.90, 95% CI 7.77-12.40).

INTERPRETATION

Postoperative ctDNA testing was a significant prognosis factor for recurrence and OS in patients with resectable cancers. However, the overall sensitivity of ctDNA-MRD detection could be better. Longitudinal monitoring can improve the sensitivity, AUSROC, and DOR.

FUNDING

Special fund project for clinical research of Qingyuan People's Hospital (QYRYCRC2023006), plan on enhancing scientific research in GMU (GZMU-SH-301).

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.

Error-Corrected Deep Targeted Sequencing of Circulating Cell-Free DNA from Colorectal Cancer Patients for Sensitive Detection of Circulating Tumor DNA

Circulating tumor DNA (ctDNA) is a promising biomarker, reflecting the presence of tumor cells. Sequencing-based detection of ctDNA at low tumor fractions is challenging due to the crude error rate of sequencing. To mitigate this challenge, we developed ultra-deep mutation-integrated sequencing (UMIseq), a fixed-panel deep targeted sequencing approach, which is universally applicable to all colorectal cancer (CRC) patients. UMIseq features UMI-mediated error correction, the exclusion of mutations related to clonal hematopoiesis, a panel of normal samples for error modeling, and signal integration from single-nucleotide variations, insertions, deletions, and phased mutations. UMIseq was trained and independently validated on pre-operative (pre-OP) plasma from CRC patients (n = 364) and healthy individuals (n = 61). UMIseq displayed an area under the curve surpassing 0.95 for allele frequencies (AFs) down to 0.05%. In the training cohort, the pre-OP detection rate reached 80% at 95% specificity, while it was 70% in the validation cohort. UMIseq enabled the detection of AFs down to 0.004%. To assess the potential for detection of residual disease, 26 post-operative plasma samples from stage III CRC patients were analyzed. From this we found that the detection of ctDNA was associated with recurrence. In conclusion, UMIseq demonstrated robust performance with high sensitivity and specificity, enabling the detection of ctDNA at low allele frequencies.

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.

Liquid biopsy for gastric cancer: Techniques, applications, and future directions

After the study of circulating tumor cells in blood through liquid biopsy (LB), this technique has evolved to encompass the analysis of multiple materials originating from the tumor, such as nucleic acids, extracellular vesicles, tumor-educated platelets, and other metabolites. Additionally, research has extended to include the examination of samples other than blood or plasma, such as saliva, gastric juice, urine, or stool. LB techniques are diverse, intricate, and variable. They must be highly sensitive, and pre-analytical, patient, and tumor-related factors significantly influence the detection threshold, diagnostic method selection, and potential results. Consequently, the implementation of LB in clinical practice still faces several challenges. The potential applications of LB range from early cancer detection to guiding targeted therapy or immunotherapy in both early and advanced cancer cases, monitoring treatment response, early identification of relapses, or assessing patient risk. On the other hand, gastric cancer (GC) is a disease often diagnosed at advanced stages. Despite recent advances in molecular understanding, the currently available treatment options have not substantially improved the prognosis for many of these patients. The application of LB in GC could be highly valuable as a non-invasive method for early diagnosis and for enhancing the management and outcomes of these patients. In this comprehensive review, from a pathologist's perspective, we provide an overview of the main options available in LB, delve into the fundamental principles of the most studied techniques, explore the potential utility of LB application in the context of GC, and address the obstacles that need to be overcome in the future to make this innovative technique a game-changer in cancer diagnosis and treatment within clinical practice.

A novel label-free capillary electrophoresis LED-induced fluorescence platform based on catalytic hairpin assembly for sensitive detection of multiple circulating tumor DNA

Circulating tumor DNA (ctDNA) is a highly promising biomarker for the early diagnosis and treatment of gastric cancer (GC). However, there is still a lack of effective and practical ctDNA detection methods. In this work, a simple and economical capillary non-gel sieving electrophoresis-LED induced fluorescence detection (NGCE-LEDIF) platform coupled with catalytic hairpin assembly (CHA) as the signal amplification strategy is proposed for quantitative detection of PIK3CA E542K and TP53 (two types of ctDNA associated with GC). We have reasonably designed two pairs of programmable oligonucleotide hairpin probes for PIK3CA E542K and TP53. Using a one-pot reaction, the presence of ctDNA triggers the cyclic amplification of CHA, forming numerous thermodynamically stable H1/H2 double-strands. The H1/H2 double-stranded DNA catalyzed by PIK3CA E542K and TP53 can be easily separated by NGCE due to their different lengths, enabling simultaneous detection of both ctDNAs. Under optimal experimental conditions, the detection limits of this strategy for detecting GC-related biomarkers PIK3CA E542K and TP53 are 20.35 pM and 19.61 pM, respectively, and can achieve 730-fold signal amplification. This strategy has a good recovery in the serum matrix. The results of this study show that this strategy has significant advantages such as high selectivity, a simple process, no special instruments and equipment, no need for fluorescence modification of hairpin probes in advance, high automation, low cost, and minimal sample consumption. This provides a powerful method for the detection of trace cancer biomarkers in the serum matrix with good application prospects.

Circulating cell-free DNA-based methylation pattern in plasma for early diagnosis of esophagus cancer

With the increased awareness of early tumor detection, the importance of detecting and diagnosing esophageal cancer in its early stages has been underscored. Studies have consistently demonstrated the crucial role of methylation levels in circulating cell-free DNA (cfDNA) in identifying and diagnosing early-stage cancer. cfDNA methylation pertains to the methylation state within the genomic scope of cfDNA and is strongly associated with cancer development and progression. Several research teams have delved into the potential application of cfDNA methylation in identifying early-stage esophageal cancer and have achieved promising outcomes. Recent research supports the high sensitivity and specificity of cfDNA methylation in early esophageal cancer diagnosis, providing a more accurate and efficient approach for early detection and improved clinical management. Accordingly, this review aims to present an overview of methylation-based cfDNA research with a focus on the latest developments in the early detection of esophageal cancer. Additionally, this review summarizes advanced analytical technologies for cfDNA methylation that have significantly benefited from recent advancements in separation and detection techniques, such as methylated DNA immunoprecipitation sequencing (MeDIP-seq). Recent findings suggest that biomarkers based on cfDNA methylation may soon find successful applications in the early detection of esophageal cancer. However, large-scale prospective clinical trials are required to identify the potential of these biomarkers.

Neoadjuvant and adjuvant therapy for biliary tract cancer: Advances and limitations

Biliary tract cancers (BTC) are a rare and aggressive consortium of malignancies, consisting of intrahepatic cholangiocarcinoma, extrahepatic cholangiocarcinoma, and gallbladder carcinoma. While most patients present with metastatic disease, a minority of patients with BTC are eligible for curative surgical resection at the time of presentation. However, these patients have poor 5-year overall survival rates and high rates of recurrence, necessitating the improvement of the neoadjuvant and adjuvant treatment of BTC. In this review, we assess the neoadjuvant and adjuvant clinical trials for the treatment of BTC and discuss the challenges and limitations of clinical trials, as well as future directions for the treatment of BTC.

Early real-world experience monitoring circulating tumor DNA in resected early-stage non-small cell lung cancer

OBJECTIVE

The study objective was to evaluate the impact of monitoring circulating tumor DNA on the detection and management of recurrence in patients with resected early-stage non-small cell lung cancer.

METHODS

Between October 2021 and March 2023, postoperative circulating tumor DNA was monitored in patients with non-small cell lung cancer (N = 108). Longitudinal blood samples (n = 378 samples) were collected for prospective circulating tumor DNA analysis at 3-month intervals after curative-intent resection. A tumor-informed assay was used for the detection and quantification of circulating tumor DNA. The primary outcome measure was a circulating tumor DNA-positive result. The secondary outcome measure was changes in practice after a circulating tumor DNA-positive result.

RESULTS

The mean age of the patients in this cohort was 68.1 years. Of the 108 patients, 12 (11.1%) were circulating tumor DNA positive at least at 1 timepoint postsurgery, of whom 8 (66.7%) had a clinically evident recurrence and the remaining 4 had limited clinical follow-up. Of the 10 patients with recurrent disease, 8 demonstrated circulating tumor DNA positivity and the remaining 2 patients had brain-only metastases. Postoperative clinical care was altered in 100% (12/12) of circulating tumor DNA-positive patients, with 58.3% (7/12) receiving an early computed tomography scan and 100% (12/12) receiving an early positron emission tomography computed tomography scan as part of their surveillance strategy. Among the patients who received an early positron emission tomography scan, 66.6% (8/12) were positive for malignant features.

CONCLUSIONS

Routine monitoring of tumor-informed circulating tumor DNA after curative intent therapy improved patient risk stratification and prognostication.

A Practical Approach to Interpreting Circulating Tumor DNA in the Management of Gastrointestinal Cancers

BACKGROUND

There is accumulating evidence supporting the clinical use of circulating tumor DNA (ctDNA) in solid tumors, especially in different types of gastrointestinal cancer. As such, appraisal of the current and potential clinical utility of ctDNA is needed to guide clinicians in decision-making to facilitate its general applicability.

CONTENT

In this review, we firstly discuss considerations surrounding specimen collection, processing, storage, and analysis, which affect reporting and interpretation of results. Secondly, we evaluate a selection of studies on colorectal, esophago-gastric, and pancreatic cancer to determine the level of evidence for the use of ctDNA in disease screening, detection of molecular residual disease (MRD) and disease recurrence during surveillance, assessment of therapy response, and guiding targeted therapy. Lastly, we highlight current limitations in the clinical utility of ctDNA and future directions.

SUMMARY

Current evidence of ctDNA in gastrointestinal cancer is promising but varies depending on its specific clinical role and cancer type. Larger prospective trials are needed to validate different aspects of ctDNA clinical utility, and standardization of collection protocols, analytical assays, and reporting guidelines should be considered to facilitate its wider applicability.

Liquid Biopsy: An Emerging Diagnostic, Prognostic, and Predictive Tool in Gastric Cancer

Liquid biopsy, a minimally invasive procedure that causes minimal pain and complication risks to patients, has been extensively studied for cancer diagnosis and treatment. Moreover, it facilitates comprehensive quantification and serial assessment of the whole-body tumor burden. Several biosources obtained through liquid biopsy have been studied as important biomarkers for establishing early diagnosis, monitoring minimal residual disease, and predicting the prognosis and response to treatment in patients with cancer. Although the clinical application of liquid biopsy in gastric cancer is not as robust as that in other cancers, biomarker studies using liquid biopsy are being actively conducted in patients with gastric cancer. Herein, we aimed to review the role of various biosources that can be obtained from patients with gastric cancer through liquid biopsies, such as blood, saliva, gastric juice, urine, stool, peritoneal lavage fluid, and ascites, by dividing them into cellular and acellular components. In addition, we reviewed previous studies on the diagnostic, prognostic, and predictive biomarkers for gastric cancer using liquid biopsy and discussed the limitations of liquid biopsy and the challenges to overcome these limitations in patients with gastric cancer.

Landscape of Innovative Methods for Early Diagnosis of Gastric Cancer: A Systematic Review

From a global perspective, gastric cancer (GC) persists as a significant healthcare issue. In the Western world, the majority of cases are discovered at late stages, when the treatment is generally unsuccessful. There are no organized screening programs outside of Asia (Japan and Republic of Korea). Traditional diagnosis techniques (such as upper endoscopy), conventional tumor markers (CEA, CA19-9, and CA72-4), radiographic imaging, and CT scanning all have drawbacks. The gold standard for the earliest detection of cancer and related premalignant lesions is still endoscopy with a proper biopsy follow-up. Since there are currently no clinically approved biomarkers for the early diagnosis of GC, the identification of non-invasive biomarkers is expected to help improve the prognosis and survival rate of these patients. The search for new screening biomarkers is currently underway. These include genetic biomarkers, such as circulating tumor cells, microRNAs, and exosomes, as well as metabolic biomarkers obtained from biofluids. Meanwhile, cutting-edge high-resolution endoscopic technologies are demonstrating promising outcomes in the visual diagnosis of mucosal lesions with the aid of linked color imaging and machine learning models. Following the PRISMA guidelines, this study examined the articles in databases such as PubMed, resulting in 167 included articles. This review discusses the currently available and emerging methods for diagnosing GC early on, as well as new developments in the endoscopic detection of early lesions of the stomach.

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.

Concordance of circulating tumor DNA and matched formalin-fixed paraffin-embedded tumor tissue in gastric cancer as a predictor of recurrence

PURPOSE

Combined analysis of the variant composition of circulating tumor DNA (ctDNA) from cell-free plasma and DNA from tumor tissue could provide insight into the implications of the genetic alterations responsible for the intratumoral and intertumoral heterogeneity of gastric cancer. We aimed to evaluate the usefulness of this approach in these patients.

METHODS

Cell-free plasma and formalin-fixed paraffin-embedded tumor tissue samples from 46 patients with gastric cancer were examined. Targeted deep sequencing was performed using a commercially available kit.

RESULTS

The cell-free DNA (cfDNA) concentration was higher in stage II-IV versus stage I patients and in larger versus smaller tumors. Only 12 of the 36 (33.3%) alterations in the tumor tissue samples were in concordance with those in the ctDNA samples. Two variants were in concordance in stage I samples and 10 in stage II-IV samples. Actionable variants that were detected in concordance were in the stage II-IV samples. Preoperative ctDNA positivity of actionable variants was significantly associated with cfDNA concentration, lymphatic invasion, N stage, and TNM stage. Cancer recurrence was significantly associated with tumor size, lymphatic/vascular invasion, TNM stage, and ctDNA-tumor tissue variant concordance.

CONCLUSION

Preoperative ctDNA genetic analysis using a multigene panel offers substantial clinical benefits when performed in conjunction with targeted deep sequencing of tumor tissue. Concordance between preoperative ctDNA and tumor tissue mutations may serve as a prognostic indicator in patients with gastric cancer.

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.

Tumor-agnostic plasma assay for circulating tumor DNA detects minimal residual disease and predicts outcome in locally advanced squamous cell carcinoma of the head and neck

BACKGROUND

Forty to fifty percent of patients with locally advanced squamous cell carcinoma of the head and neck (LA SCCHN) relapse despite multimodal treatment. Circulating tumor DNA (ctDNA) has the potential to detect minimal residual disease (MRD) after curative-intent therapy and to identify earlier which patients will progress. We developed a tumor-agnostic plasma ctDNA assay to detect MRD in unselected LA SCCHN with the aim of predicting progression-free survival (PFS) and overall survival without the need for tumor sequencing.

PATIENTS AND METHODS

A 26-gene next-generation sequencing panel was constructed that included the most frequently mutated genes in SCCHN and two HPV-16 genes. MRD was assessed in each patient through an in-house informatic workflow informed by somatic mutations identified in the corresponding pre-treatment plasma sample. The presence of MRD was defined as the detection of ctDNA in one plasma sample collected within 1-12 weeks of the end of curative treatment. The primary endpoint was the PFS rate at 2 years. At least 32 patients were planned for inclusion with the hypothesis that PFS at 2 years was >80% in MRD-negative patients and <30% in MRD-positive patients (α = 0.05, β = 0.9).

RESULTS

We sequenced DNA from 116 plasma samples derived from 53 LA SCCHN patients who underwent curative-intent treatment. ctDNA was detected in 41/53 (77%) patients in the pre-treatment samples. Out of these 41 patients, 17 (41%) were MRD positive after treatment. The 2-year PFS rate was 23.53% (9.9% to 55.4%) and 86.6% (73.4% to 100%) in MRD-positive and MRD-negative patients, respectively (P < 0.05). Median survival was 28.37 months (14.30 months-not estimable) for MRD-positive patients and was not reached for the MRD-negative cohort (P = 0.011).

CONCLUSIONS

Our ctDNA assay detects MRD in LA SCCHN and predicts disease progression and survival without the need for tumor sequencing, making this approach easily applicable in daily practice.

Circulating tumor DNA predicts recurrence and assesses prognosis in operable gastric cancer: A systematic review and meta-analysis

BACKGROUND

Selecting the appropriate patient for further treatment after surgery for gastric cancer can improve the patient prognosis. Circulating tumor DNA (ctDNA) has the potential to predict recurrence and prognosis after gastric cancer surgery, but the results are still inconclusive. As the completed studies had small sample sizes and were inconsistent, a meta-analysis was conducted to assess the effect of ctDNA on recurrence and prognosis after gastric cancer surgery.

METHODS

PubMed, Embase, Scopus, and the Web of Science were searched for potentially eligible studies published up to April 7, 2023. Pooled relative risk (RR) and pooled hazard ratio (HR) were calculated to evaluate recurrence, recurrence-free survival (RFS), and overall survival (OS) following gastric cancer surgery.

RESULTS

A pooled analysis revealed that patients who were ctDNA positive before and after surgery were at a high risk of gastric cancer recurrence (RR = 1.79, 95% CI: 1.19-2.71; RR = 3.17, 95% CI: 2.36-4.25). The pooled data revealed that ctDNA-positive patients had a poorer RFS and OS (HR = 6.37, 95% CI: 2.70-15.01; HR = 4.58, 95% CI: 1.68-12.49).

CONCLUSIONS

ctDNA-positive patients were at a high risk of recurrence after gastric cancer surgery and had a poorer prognosis. Hence, ctDNA-positive patients needed close follow-up and further treatment.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Sintilimab plus fluorouracil, leucovorin, oxaliplatin and docetaxel regimen as neoadjuvant therapy for resectable gastric cancer and biomarker exploration

At present, preoperative chemotherapy is the standard of care for the neoadjuvant treatment of potentially resectable gastric cancer (GC). However, because the efficacy and prognosis are not ideal, curative effects for this population are unsatisfactory. With the development of immune checkpoint inhibitors, the results of a few encouraging early trials of immunotherapeutic agents as neoadjuvant therapies for resectable GC have been reported. However, markers of the efficacy of immune checkpoint inhibitors remain unclear. This prospective single-center, single-arm observational study was designed to evaluate the efficacy of sintilimab plus the fluorouracil, leucovorin, oxaliplatin and docetaxel regimen as a neoadjuvant treatment for localized GC. More importantly, this work assesses multiple dimensions and include ctDNA, the immune microenvironment and intestinal microbiome to explore correlations between biomarkers and neoadjuvant therapeutic efficacy. Clinical trial registration: ChiCTR2200061629 (www.chictr.org.cn/index.aspx).

Circulating tumor DNA based minimal residual disease detection and adjuvant treatment decision-making for muscle-invasive bladder cancer guided by modern clinical trials

Up to 430,000 cases of bladder cancer are diagnosed each year worldwide. A proposed method for non-invasive monitoring has been to utilize a "liquid biopsy." Liquid biopsy has been proposed as a non-invasive method of testing biomarkers in bodily fluids in order to detect and survey cancer. The liquid biopsy could be utilized to obtain information regarding circulating tumor cells, circulating cell-free tumor DNA, circulating cell-free tumor RNA, and more. It is currently being investigated to help guide adjuvant therapy and improve oncological outcomes. We highlight an array of exciting past and ongoing clinical trials regarding ctDNA and adjuvant therapy in regard to urothelial carcinoma which we believe to be amongst the leaders in the field.

Efficacy and safety of XELOX combined with anlotinib and penpulimab vs XELOX as an adjuvant therapy for ctDNA-positive gastric and gastroesophageal junction adenocarcinoma: a protocol for a randomized, controlled, multicenter phase II clinical trial (EXPLORING study)

Background

The efficacy of current adjuvant chemotherapy for gastric adenocarcinoma/gastroesophageal junction adenocarcinoma (GA/GEJA) leaves much to be desired. ctDNA could serve as a potential marker to identify patients who are at higher risk of recurrence. Reinforcing standard adjuvant chemotherapy with immunotherapy has already been indicated to significantly improve clinical outcome, albeit such evidence is rare in GA/GEJA. Here, we intend to explore the clinical benefit of the reinforcement of adjuvant immunotherapy and antiangiogenics alongside with chemotherapy in patients who are deemed in high risk of recurrence by ctDNA analysis, which might shed light on further improvements in adjuvant therapy for GA/GEJA.

Methods/Design

This study is designed as a prospective, multicenter, randomized, controlled phase II study in patients histologically or cytologically diagnosed with GA/GEJA who underwent D2 gastrectomy and achieved R0 or R1 resection. From February 2022, a total of 300 stage III patients will be enrolled and subjected according to ctDNA sequencing results, and those with positive results will subsequently be randomized 1:1 to arm A or B. Patients in arm A will receive anlotinib, penpulimab and XELOX for 6-8 cycles, maintained with anlotinib and penpulimab for up to 1 year, while patients in arm B will receive XELOX alone for 6-8 cycles. ctDNA-negative patients will be assigned to arm C, and patients who are ctDNA positive but failed in randomization will be assigned to arm D. Patients in arms C and D will receive the investigator's choice of therapy. The primary endpoint is the median disease-free survival (DFS) of arm A versus arm B determined via CT/MRI imaging. Secondary endpoints include the DFS of ctDNA positive patients versus ctDNA negative patients, the 2- and 3-year DFS rates, overall survival (OS), the impact of hallmark molecules on the treatment response, adverse events (AEs), and the impact of nutrition status or exercise on recurrence.

Discussion

We expect that ctDNA would be a strong prognostic factor and ctDNA-positive patients are at higher risk of relapse than ctDNA-negative patients. The addition of anlotinib and penpulimab to XELOX, may contribute to delaying relapse in ctDNA-positive patients.

Trial registration

https://www.clinicaltrials.gov, identifier NCT05494060.

[Research progress on circulating tumor DNA as a biomarker for minimal residual disease in solid tumors]

Circulating tumor DNA (ctDNA) is emerging as a novel biomarker for tumor evaluation, offering advantages such as high sensitivity and specificity, minimal invasiveness, and absence of radiation. Currently, various techniques including gene sequencing and PCR are employed for ctDNA detection. The utilization of ctDNA for monitoring minimal residual disease (MRD) enables comprehensive assessment of tumor status and early identification of tumor recurrence, achieving a remarkable detection sensitivity of 0.01%. Therefore, ctDNA holds promise as a biomarker for early diagnosis, treatment response monitoring, and prognosis prediction in solid tumors. This article reviews the commonly used methods for detecting ctDNA and their advantages in evaluating tumor MRD and guiding clinical diagnosis and treatment.

Study protocol of a phase II clinical trial evaluating the efficacy of neoadjuvant intraperitoneal and systemic albumin-bound paclitaxel combined with camrelizumab and S-1 in the treatment of patients with exfoliative cell-positive gastric cancer

Background

Currently, gastric cancer with positive lavage cytology without gross peritoneal dissemination (GC-CY1) is a special type of metastatic form with poor prognosis. Consensus guidelines on treatment strategies for patients with GC-CY1 have not been established. This study involves a single-arm, prospective, phase II clinical trial to examine the efficacy and safety of neoadjuvant intraperitoneal and systemic (NIPS) albumin-bound paclitaxel combined with Camrelizumab and S-1 in the treatment of GC-CY1 patients.

Methods/design

This is a prospective single-center exploratory study, and the primary endpoints of the trial are R0 resection rate and conversion rate of abdominal free cancer cells (FCCs), with secondary endpoints of 3-year progression-free survival (PFS); 3-year overall survival (OS); objective remission rate (ORR); disease control rate (DCR); safety and TRG classification.

Discussion

This study is the first to apply NIPS albumin-bound paclitaxel combined with Camrelizumab and S-1 to the conversion therapy of GC-CY1 patients. It is speculated that this combination of regimens will increase the negative conversion rate of FCCs by 20%, which will provide innovative insights into conversion treatment ideas for GC-CY1 patients to be managed in a more comprehensive and optimized manner.

Clinical trial registration

http://clinicaltrials.gov/, identifier NCT05410847.

The Emerging Role of Circulating Tumor DNA in Non-Colorectal Gastrointestinal Cancers

Assays to detect circulating tumor DNA (ctDNA) have multiple clinically important applications in management of multiple types of gastrointestinal cancers. Different methodologies of ctDNA detection have varying sensitivities and potential applications in different contexts. For patients with localized cancers treated for curative intent, ctDNA detection is associated with prognosis in multiple cancer types, and persistent detection of ctDNA after surgical resection is highly concerning for minimal residual disease (MRD) and forebodes impending radiographic and clinical recurrence. CtDNA assays for comprehensive genomic profiling enable genotyping of cancers in the absence of tumor tissue data, and longitudinal testing can also characterize clonal evolution and emergence of putative resistance mechanisms upon treatment with targeted agents. These applications have proven instructive in patients with HER2-amplified gastric and esophageal cancers and in patients with FGFR2 fusion cholangiocarcinomas. In this review, we summarize data supporting the role of ctDNA as a novel predictive and prognostic biomarker and potential impacts on current management of patients with pancreatic, gastroesophageal, and hepatobiliary cancers.

Current management of gastric adenocarcinoma: a narrative review

Gastric adenocarcinoma is a leading cause of cancer death worldwide. The management of this aggressive malignancy largely depends on tumor characteristics especially stage. Superficial early-stage gastric cancer can be safely managed by endoscopic resection, though clear negative deep and lateral margins must be obtained. Optimal surgical resection is an essential part of the treatment for locally advanced gastric adenocarcinoma, with perioperative and adjuvant therapies having significant impact on long-term outcomes. Chemoradiation is reserved for patients with suboptimal surgical resection. Recent therapeutic advances have prolonged survival in patients with metastatic gastric adenocarcinoma, include checkpoint inhibitors and biomarker-directed therapy. Targeted therapies in gastric adenocarcinoma include monoclonal antibodies directed against vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor-2 (VEGFR-2), and human epidermal growth factor receptor 2 (HER2). While anti-VEGF therapies were not found beneficial in the perioperative setting, the effectiveness of HER2 targeted agents in resectable HER2-positive gastric adenocarcinoma is being studied. Microsatellite instability (MSI) varies greatly in patients with gastric adenocarcinoma between 5-20% based on ethnic origin, tumour heterogeneity and staging. The role chemotherapy in the perioperative setting for patients with MSI-high tumors remains controversial while immunotherapy demonstrates promising results in preliminary studies. Immune checkpoint inhibitors in combination with chemotherapy has been shown to improve outcomes in patients with metastatic gastric adenocarcinoma who express programmed cell death 1 ligand 1 (PD-L1) and is now being investigated in the perioperative setting.

Postoperative circulating tumor DNA detection and CBLB mutations are prognostic biomarkers for gastric cancer

BACKGROUND

Several studies have demonstrated that circulating tumor DNA (ctDNA) can be used to predict the postoperative recurrence of several cancers. However, there are few studies on the use of ctDNA as a prognosis tool for gastric cancer (GC) patients.

OBJECTIVE

This study aims to determine whether ctDNA could be used as a prognostic biomarker in GC patients through multigene-panel sequencing.

METHODS

Using next-generation sequencing (NGS) Multigene Panels, the mutational signatures associated with the prognosis of GC patients were identified. We calculated the survival probability with Kaplan-Meier and used the Log-rank test to compare survival curves between ctDNA-positive and ctDNA-negative groups. Potential application of radiology combined with tumor plasma biomarker analysis of ctDNA in GC patients was carried out.

RESULTS

Disease progression is more likely in ctDNA-positive patients as characterized clinically by a generally higher T stage and a poorer therapeutic response (P < 0.05). ctDNA-positive patients also had worse overall-survival (OS: P = 0.203) and progression-free survival (PFS: P = 0.037). The combined analysis of ctDNA, radiological, and serum biomarkers in four patients indicated that ctDNA monitoring can be a good complement to radiological and plasma tumor markers for GC patients. Kaplan-Meier analysis using a cohort of GC patients in the TCGA database showed that patients with CBLB mutations had shorter OS and PFS than wild-type patients (OS: P = 0.0036; PFS: P = 0.0027).

CONCLUSIONS

This study confirmed the utility and feasibility of ctDNA in the prognosis monitoring of gastric cancer.

A Liquid Biopsy Signature for the Early Detection of Gastric Cancer in Patients

BACKGROUND & AIMS

Diagnosing gastric cancer (GC) while the disease remains eligible for surgical resection is challenging. In view of this clinical challenge, novel and robust biomarkers for early detection thus improving prognosis of GC are necessary. The present study is to develop a blood-based long noncoding RNA (LR) signature for the early-detection of GC.

METHODS

The present 3-step study incorporated data from 2141 patients, including 888 with GC, 158 with chronic atrophic gastritis, 193 with intestinal metaplasia, 501 healthy donors, and 401 with other gastrointestinal cancers. The LR profile of stage I GC tissue samples were analyzed using transcriptomic profiling in discovery phase. The extracellular vesicle (EV)-derived LR signature was identified with a training cohort (n = 554) and validated with 2 external cohorts (n = 429 and n = 504) and a supplemental cohort (n = 69).

RESULTS

In discovery phase, one LR (GClnc1) was found to be up-regulated in both tissue and circulating EV samples with an area under the curve (AUC) of 0.9369 (95% confidence interval [CI], 0.9073-0.9664) for early-stage GC (stage I/II). The diagnostic performance of this biomarker was further confirmed in 2 external validation cohorts (Xi'an cohort, AUC: 0.8839; 95% CI: 0.8336-0.9342; Beijing cohort, AUC: 0.9018; 95% CI: 0.8597-0.9439). Moreover, EV-derived GClnc1 robustly distinguished early-stage GC from precancerous lesions (chronic atrophic gastritis and intestinal metaplasia) and GC with negative traditional gastrointestinal biomarkers (CEA, CA72-4, and CA19-9). The low levels of this biomarker in postsurgery and other gastrointestinal tumor plasma samples indicated its GC specificity.

CONCLUSIONS

EV-derived GClnc1 serves as a circulating biomarker for the early detection of GC, thus providing opportunities for curative surgery and improved survival outcomes.

Minimal residual disease in solid tumors: an overview

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

Monitoring of gastrointestinal carcinoma via molecular residual disease with circulating tumor DNA using a tumor-informed assay

BACKGROUND

Circulating tumor DNA (ctDNA)-based minimal residual disease (MRD) detection, which can identify disease relapse ahead of radiological imaging, has shown promising performance. The objective of this study was to develop and validate OriMIRACLE S (Minimal Residual Circulating Nucleic Acid Longitudinal Detection in Solid Tumor), a highly sensitive and specific tumor-informed assay for MRD detection.

METHODS

Tumor-specific somatic single nucleotide variants (SNVs) were identified via whole exome sequencing of tumor tissue and matched germline DNA. Clonal SNVs were selected using the OriSelector algorithm for patient-specific, multiplex PCR-based NGS assays in MRD detection. Plasma-free DNA from patients with gastrointestinal tumors prior to and following an operation, and during monitoring, were ultradeep sequenced.

RESULTS

The detection of three positive sites was sufficient to achieve nearly 100% overall sample level sensitivity and specificity and was determined by calculating binomial probability based on customized panels containing 21 to 30 variants. A total of 127 patients with gastrointestinal tumors were enrolled in our study. Preoperatively, MRD was positive in 18 of 26 patients (69.23%). Following surgery, MRD was positive in 24 of 82 patients (29.27%). The positivity rate for MRD was 33.33% (n = 18) for gastric adenocarcinoma and 32.26% (n = 62) for colorectal cancer. Twenty (20) of 59 patients (34.48%) experienced a change in MRD status over the monitoring period. Patients 8 and 31 responded to 3 cycles of systemic therapy, after which levels for all ctDNA dropped below the detection limit. Patient 53 was an example of using MRD to predict tumor metastasis. Patient 55 showed a weak response to treatments first and respond to new systemic therapy after tumor progression.

CONCLUSION

Our study identified a sensitive and specific clinical detection method for low frequency ctDNA, and explored the detection performance of this technology in gastrointestinal tumors.

The evolution of minimal residual disease: key insights based on a bibliometric visualization analysis from 2002 to 2022

Background

The topic of minimal residual disease (MRD) has emerged as a crucial subject matter in the domain of oncology in recent years. The detection and monitoring of MRD have become essential for the diagnosis, treatment, and prognosis of various types of malignancy.

Aims

The purpose of this study is to explore the research trends, hotspots, and frontiers of MRD in the last two decades through bibliometric analysis.

Methods

We employed Web of Science databases to carry out a bibliometric visualization analysis of research on 8,913 academic papers about MRD research from 2002 to 2022. VOSviewer, CiteSpace, RStudio, and a bibliometric online analysis platform were mainly used to conduct co-occurrence analysis and cooperative relationship analysis of countries/regions, institutions, journals, and authors in the literature. Furthermore, co-occurrence, co-citation, and burst analyses of keyword and reference were also conducted to generate relevant knowledge maps.

Results

In the past 20 years, the number of MRD research papers has presented an overall rising trend, going through three stages: a plateau, development, and an explosion. The output of articles in the United States was notably superior and plays a dominant role in this field, and the Netherlands had the highest average citation per article. The most productive and influential institution was the University of Texas MD Anderson Cancer Center. Blood published the most papers and was the most cited journal. A collection of leading academics has come to the fore in the research field, the most prolific of which is Kantarjian HM. It was found that the application of MRD in "acute myeloid leukemia", "acute lymphoblastic leukemia", "multiple myeloma", as well as the detection technology of MRD, are the research hotspots and frontiers in this domain. Furthermore, we analyzed the co-citation network of references and found that the top 10 co-cited references were all associated with MRD in hematological malignancies.

Conclusion

This bibliometric visualization analysis conducted a thorough exploration into the research hotspots and trends in MRD from 2002 to 2022. Our findings can aid researchers in recognizing possible collaborations, guiding future research directions, and fostering the growth of MRD detection and monitoring technologies.

Novel Biomarkers of Gastric Cancer: Current Research and Future Perspectives

Gastric cancer is a heterogeneous disease with diverse histological and genomic subtypes, making it difficult to demonstrate treatment efficacy in clinical trials. However, recent efforts have been made to identify molecular biomarkers with prognostic and predictive implications to better understand the broad heterogeneity of gastric cancer and develop effective targeted therapies for it. HER2 overexpression, HER2/neu amplification, MSI-H, and PD-L1+ are predictive biomarkers in gastric cancer, and a growing number of clinical trials based on novel biomarkers have demonstrated the efficacy of targeted therapies alone or in combination with conventional chemotherapy. Enrichment design clinical trials of targeted therapies against FGFR2b and claudin 18.2 have demonstrated efficacy in unresectable advanced gastric cancer. Nonetheless, it is essential to continuously validate promising molecular biomarkers and introduce them into clinical practice to optimize treatment selection and improve patient outcomes. In this review, we focused on established (PD-L1, HER2, MSI) and emerging biomarkers (FGFR2, CLDN18.2) in gastric cancer, their clinical significance, detection methods, limitations, and molecular agents that target these biomarkers.

Case Report: A rare synchronous multiple gastric carcinoma achieved progression-free disease through NGS-guided serial treatment

Synchronous multiple gastric carcinoma (SMGC) is a rare condition characterized by the simultaneous occurrence of two or more primary malignant tumors in the stomach, each with its own distinct pathological morphology. SMGC differs from gastric metastases, which originate from primary gastric or non-gastric tumors. At present, the incidence of SMGC is low in China, with no established guidelines for standard treatment. Here, we report a rare case of advanced SMGC that achieved long-lasting clinical benefits through a treatment strategy informed by next-generation sequencing (NGS). Dynamically monitoring of the tumor and/or circulating cell-free DNA guided the patient's treatment sequentially. The patient received anti-HER2 therapy, followed by immunotherapy, pembrolizumab in combination with trastuzumab and chemotherapy, and ultimately underwent successful total gastrectomy. This case highlights a novel approach of utilizing liquid biopsy-based NGS to gain insights into disease progression and molecular response to NGS-guided treatment in SMGC patients.

Current and emerging applications of liquid biopsy in pan-cancer

Cancer morbidity and mortality are growing rapidly worldwide and it is urgent to develop a convenient and effective method that can identify cancer patients at an early stage and predict treatment outcomes. As a minimally invasive and reproducible tool, liquid biopsy (LB) offers the opportunity to detect, analyze and monitor cancer in any body fluids including blood, complementing the limitations of tissue biopsy. In liquid biopsy, circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) are the two most common biomarkers, displaying great potential in the clinical application of pan-cancer. In this review, we expound the samples, targets, and newest techniques in liquid biopsy and summarize current clinical applications in several specific cancers. Besides, we put forward a bright prospect for further exploring the emerging application of liquid biopsy in the field of pan-cancer precision medicine.

Circulating Tumor DNA in Gastric Adenocarcinoma: Future Clinical Applications and Perspectives

Gastric cancer (GC) is still one of the most aggressive cancers with a few targetable alterations and a dismal prognosis. A liquid biopsy allows for identifying and analyzing the DNA released from tumor cells into the bloodstream. Compared to tissue-based biopsy, liquid biopsy is less invasive, requires fewer samples, and can be repeated over time in order to longitudinally monitor tumor burden and molecular changes. Circulating tumor DNA (ctDNA) has been recognized to have a prognostic role in all the disease stages of GC. The aim of this article is to review the current and future applications of ctDNA in gastric adenocarcinoma, in particular, with respect to early diagnosis, the detection of minimal residual disease (MRD) following curative surgery, and in the advanced disease setting for treatment decision choice and therapeutic monitoring. Although liquid biopsies have shown potentiality, pre-analytical and analytical steps must be standardized and validated to ensure the reproducibility and standardization of the procedures and data analysis methods. Further research is needed to allow the use of liquid biopsy in everyday clinical practice.

Novel biomarkers for early detection of gastric cancer

Gastric cancer (GC) remains a leading cause of cancer-related death worldwide. Less than half of GC cases are diagnosed at an advanced stage due to its lack of early symptoms. GC is a heterogeneous disease associated with a number of genetic and somatic mutations. Early detection and effective monitoring of tumor progression are essential for reducing GC disease burden and mortality. The current widespread use of semi-invasive endoscopic methods and radiologic approaches has increased the number of treatable cancers: However, these approaches are invasive, costly, and time-consuming. Thus, novel molecular noninvasive tests that detect GC alterations seem to be more sensitive and specific compared to the current methods. Recent technological advances have enabled the detection of blood-based biomarkers that could be used as diagnostic indicators and for monitoring postsurgical minimal residual disease. These biomarkers include circulating DNA, RNA, extracellular vesicles, and proteins, and their clinical applications are currently being investigated. The identification of ideal diagnostic markers for GC that have high sensitivity and specificity would improve survival rates and contribute to the advancement of precision medicine. This review provides an overview of current topics regarding the novel, recently developed diagnostic markers for GC.

Neoadjuvant PD-1 blockade plus chemotherapy versus chemotherapy alone in locally advanced stage II-III gastric cancer: A single-centre retrospective study

BACKGROUND

PD-1 blockade has been shown to have promising efficacy and acceptable safety profiles in advanced and metastatic gastric cancer; however, the efficacy and safety of neoadjuvant PD-1 blockade-based immunotherapy plus chemotherapy in locally advanced gastric cancer (LAGC) remain uncertain.

METHODS

We performed a retrospective review of patients with LAGC who received neoadjuvant treatment followed by D2 radical resection at the Affiliated Hospital of Qingdao University from 2019 to 2021. The primary aim was to investigate the difference in pathological response rates between neoadjuvant PD-1 immunotherapy plus chemotherapy and neoadjuvant chemotherapy alone. Multivariable models for pathological complete response (pCR) were constructed to investigate the factors that facilitate pCR.

TRIAL REGISTRATION

QYFYWZLL27406.

RESULTS

A total of 77 patients were included in the analysis, among whom 34 (44.2%) received neoadjuvant PD-1 blockade immunotherapy plus chemotherapy. A higher pCR rate was observed in the neoadjuvant PD-1 blockade immunotherapy plus chemotherapy group (8 of 34, 23.5% vs. 2 of 43, 4.7%, P=0.019). Multivariate logistic regression analysis of pCR revealed neoadjuvant PD-1 blockade plus chemotherapy regimen promoted pCR (OR 12.95, P=0.016). Regarding safety, 76.5% (26 of 34) of patients in the PD-1 blockade plus chemotherapy group and 76.7% (33 of 43) of patients in the chemotherapy group experienced treatment-related adverse events (TRAEs), and grade 3 or worse adverse events were 29.4% (10 of 34) and 34.9% (15 of 43), respectively.

CONCLUSION

Neoadjuvant PD-1 blockade plus chemotherapy induced a higher pCR rate than neoadjuvant chemotherapy, and the combined therapy was tolerable in LAGC patients.

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.

Current Applications of Liquid Biopsy in Gastrointestinal Cancer Disease-From Early Cancer Detection to Individualized Cancer Treatment

Worldwide, gastrointestinal (GI) cancers account for a significant amount of cancer-related mortality. Tests that allow an early diagnosis could lead to an improvement in patient survival. Liquid biopsies (LBs) due to their non-invasive nature as well as low risk are the current focus of cancer research and could be a promising tool for early cancer detection. LB involves the sampling of any biological fluid (e.g., blood, urine, saliva) to enrich and analyze the tumor's biological material. LBs can detect tumor-associated components such as circulating tumor DNA (ctDNA), extracellular vesicles (EVs), and circulating tumor cells (CTCs). These components can reflect the status of the disease and can facilitate clinical decisions. LBs offer a unique and new way to assess cancers at all stages of treatment, from cancer screenings to prognosis to management of multidisciplinary therapies. In this review, we will provide insights into the current status of the various types of LBs enabling early detection and monitoring of GI cancers and their use in in vitro diagnostics.

Immune Checkpoint Inhibitors for Solid Tumors in the Adjuvant Setting: Current Progress, Future Directions, and Role in Transplant Oncology

The rationale for administering immune checkpoint inhibitors (ICIs) in the adjuvant setting is to eradicate micro-metastases and, ultimately, prolong survival. Thus far, clinical trials have demonstrated that 1-year adjuvant courses of ICIs reduce the risk of recurrence in melanoma, urothelial cancer, renal cell carcinoma, non-small cell lung cancer, and esophageal and gastroesophageal junction cancers. Overall survival benefit has been shown in melanoma while survival data are still not mature in other malignancies. Emerging data also show the feasibility of utilizing ICIs in the peri-transplant setting for hepatobiliary malignancies. While ICIs are generally well-tolerated, the development of chronic immune-related adverse events, typically endocrinopathies or neurotoxicities, as well as delayed immune-related adverse events, warrants further scrutiny regarding the optimal duration of adjuvant therapy and requires a thorough risk-benefit determination. The advent of blood-based, dynamic biomarkers such as circulating tumor DNA (ctDNA) can help detect minimal residual disease and identify the subset of patients who would likely benefit from adjuvant treatment. In addition, the characterization of tumor-infiltrating lymphocytes, neutrophil-to-lymphocyte ratio, and ctDNA-adjusted blood tumor mutation burden (bTMB) has also shown promise in predicting response to immunotherapy. Until additional, prospective studies delineate the magnitude of overall survival benefit and validate the use of predictive biomarkers, a tailored, patient-centered approach to adjuvant ICIs that includes extensive patient counseling on potentially irreversible adverse effects should be routinely incorporated into clinical practice.

State of the Art: ctDNA in Upper Gastrointestinal Malignancies

Circulating tumor DNA (ctDNA) has emerged as a promising non-invasive source to characterize genetic alterations related to the tumor. Upper gastrointestinal cancers, including gastroesophageal adenocarcinoma (GEC), biliary tract cancer (BTC) and pancreatic ductal adenocarcinoma (PADC) are poor prognostic malignancies, usually diagnosed at advanced stages when no longer amenable to surgical resection and show a poor prognosis even for resected patients. In this sense, ctDNA has emerged as a promising non-invasive tool with different applications, from early diagnosis to molecular characterization and follow-up of tumor genomic evolution. In this manuscript, novel advances in the field of ctDNA analysis in upper gastrointestinal tumors are presented and discussed. Overall, ctDNA analyses can help in early diagnosis, outperforming current diagnostic approaches. Detection of ctDNA prior to surgery or active treatment is also a prognostic marker that associates with worse survival, while ctDNA detection after surgery is indicative of minimal residual disease, anticipating in some cases the imaging-based detection of progression. In the advanced setting, ctDNA analyses characterize the genetic landscape of the tumor and identify patients for targeted-therapy approaches, and studies show variable concordance levels with tissue-based genetic testing. In this line, several studies also show that ctDNA serves to follow responses to active therapy, especially in targeted approaches, where it can detect multiple resistance mechanisms. Unfortunately, current studies are still limited and observational. Future prospective multi-center and interventional studies, carefully designed to assess the value of ctDNA to help clinical decision-making, will shed light on the real applicability of ctDNA in upper gastrointestinal tumor management. This manuscript presents a review of the evidence available in this field up to date.