Emerging role of liquid biopsy in rat sarcoma virus mutated metastatic colorectal cancer:A case report

BACKGROUND In patients with metastatic colorectal cancer(mCRC),the treatment options are limited and have been proved to be affected by rat sarcoma virus(RAS)mutational status.In RAS wild-type(wt)patients,the combination of antiepidermal growth factor receptor(EGFR)monoclonal antibodies with chemotherapy(CT)is more effective than CT alone.On the other hand,RAS-mutated patients are not eligible for treatment with anti-EGFR antibodies.CASE SUMMARY Eleven patients with initially RAS-mutated mCRC were followed from diagnosis to May 2022.At the time of cell-free DNA determination,five patients had undergone one CT line,five patients had undergone two CT lines,and one patient had undergone three CT lines(all in combination with bevacizumab).At the second and third treatment lines[second line(2L),third line(3L)],patients with neo-RAS wt received a combination of CT and cetuximab.In neo-RAS wt patients treated with anti-EGFR,our findings indicated an increase in progression-free survival for both 2L and 3L(14.5 mo,P=0.119 and 3.9 mo,P=0.882,respectively).Regarding 2L overall survival,we registered a slight increase in neo-RAS wt patients treated with anti-EGFR(33.6 mo vs 32.4 mo,P=0.385).At data cut-off,two patients were still alive:A RAS-mutated patient undergoing 3L treatment and a neo-RAS wt patient who received 2L treatment with anti-EGFR(ongoing).CONCLUSION Our case series demonstrated that monitoring RAS mutations in mCRC by liquid biopsy may provide an additional treatment line for neo-RAS wt patients.

Emerging roles of non-coding RNAs in colorectal cancer oxaliplatin resistance and liquid biopsy potential

Colorectal cancer(CRC)is one of the most common malignancies of the digestive tract,with the annual incidence and mortality increasing consistently.Oxaliplatinbased chemotherapy is a preferred therapeutic regimen for patients with advanced CRC.However,most patients will inevitably develop resistance to oxaliplatin.Many studies have reported that non-coding RNAs(ncRNAs),such as microRNAs,long non-coding RNAs,and circular RNAs,are extensively involved in cancer progression.Moreover,emerging evidence has revealed that ncRNAs mediate chemoresistance to oxaliplatin by transcriptional and post-transcriptional regulation,and by epigenetic modification.In this review,we summarize the mechanisms by which ncRNAs regulate the initiation and development of CRC chemoresistance to oxaliplatin.Furthermore,we investigate the clinical application of ncRNAs as promising biomarkers for liquid CRC biopsy.This review provides new insights into overcoming oxaliplatin resistance in CRC by targeting ncRNAs.

Liquid biopsy in colorectal cancer:No longer young,but not yet old

Colorectal cancer(CRC)is one of the most prevalent cancers and the second leading cause of cancer-related deaths worldwide.The treatment strategy employed in CRC patients is becoming highly dependent on molecular characteristics present at diagnosis and during treatment.Liquid biopsy is an emerging field in the management of this cancer,and its relevance as a potential diagnostic,prognostic,monitoring,and therapeutic tool makes it a viable strategy in the clinical management of CRC patients.Liquid biopsy also has certain limitations,but these limitations seem to be at the reach of near-future technological development.In this letter,we focus on the clinical perspectives of liquid biopsy in CRC with particular regard to the various biomarkers recently identified that have been shown to be potentially useful in multiple aspects of early stage or metastatic CRC.

Liquid biopsy to detect resistance mutations against anti-epidermal growth factor receptor therapy in metastatic colorectal cancer

Colorectal cancer(CRC) is a major cause of mortality worldwide, associated with a steadily growing prevalence. Notably, the identification of KRAS, NRAS, and BRAF mutations has markedly improved targeted CRC therapy by affording treatments directed against the epidermal growth factor receptor(EGFR) and other anti-angiogenic therapies. However, the survival benefit conferred by these therapies remains variable and difficult to predict, owing to the high level of molecular heterogeneity among patients with CRC. Although classification into consensus molecular subtypes could optimize response prediction to targeted therapies, the acquisition of resistance mutations to targeted therapy is, in part, responsible for the lack of response in some patients. However, the acquisition of such mutations can induce challenges in clinical practice. The utility of liquid biopsy to detect resistance mutations against anti-EGFR therapy has recently been described. This approach may constitute a new standard in the decision algorithm for targeted CRC therapy.

Cancer-associated fibroblasts of colorectal cancer: Translationalprospects in liquid biopsy and targeted therapy

Colorectal cancer (CRC) is a major global health concern. Accumulation of cancer-associated fibroblasts(CAFs) in CRC is associated with poor prognosis and disease recurrence. CAFs are the main cellular component ofthe tumor microenvironment. CAF-tumor cell interplay, which is facilitated by various secretomes, drives colorectalcarcinogenesis. The complexity of CAF populations contributes to the heterogeneity of CRC and influences patientsurvival and treatment response. Due to their significant roles in colorectal carcinogenesis, different clinicalapplications utilizing or targeting CAFs have been suggested. Circulating CAFs (cCAFs) which can be detected inblood samples, have been proposed to help in determining patient prognosis and enables the detection of cancerthrough liquid biopsy. Liquid biopsy is gaining traction as it is non-invasive, allows frequent and easy sampling, andshows concordance to tissue biopsy analysis. In addition, CAF-targeted therapy is currently being studied extensivelyto be used as one of the treatment avenues for CRC. Various mechanisms of CAF-targeted therapy have beenreported, including blocking the signaling pathways involving CAFs and cancer cells, thus abolishing the CAF-tumorcell crosstalk and subsequently hindering tumorigenesis. These translational applications of cCAFs and utilization ofCAFs as key targets for CRC therapy, although still in the early phases of development, will potentially improve CRCpatient management in the future.

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.

Colorectal cancer screening: Modalities and adherence

In the last decade,several studies have explored various modalities and strategies for colorectal cancer(CRC)screening,taking into account epidemiological data,individual characteristics,and socioeconomic factors.In this editorial,we comment further on a retrospective study by Agatsuma et al published in the recent issue of the World Journal of Gastroenterology.Our focus is on screening trends,particularly in relation to efforts to improve the currently suboptimal uptake among the general population worldwide,aiming to enhance early diagnosis rates of CRC.There is a need to raise awareness through health edu-cation programs and to consider the use of readily available,non-invasive screening methods.These strategies are crucial for attracting screen-eligible populations to participate in first-line screening,especially those in high-or average-risk groups and in regions with limited resources.Liquid biopsies and biomarkers represent rapidly evolving trends in screening and diagnosis;however,their clinical relevance has yet to be standardized.

Utilization of molecular genetic approaches for colorectal cancer screening

The feasibility of population screening for colorectal cancer has been demonstrated in several studies.Most of these studies have considered individual characteristics,diagnostic approaches,epidemiological data,and socioeconomic factors.In this article,we comment on an editorial by Metaxas et al published in the recent issue of the journal.The authors emphasized the need to raise public awareness through health education programs and the possibility of using easily accessible non-invasive screening methods.Here,we focus on non-invasive molecular genetic approaches that can aid in colorectal cancer screening.On the one hand,we highlighted the use of tumor DNA/RNA markers directly for screening and,on the other hand,underline the use of polygenic risk assessment and hereditary predisposition to select individuals for more thorough cancer screening.

Cell-free DNA liquid biopsy for early detection of gastrointestinal cancers:A systematic review

BACKGROUND Gastrointestinal tumors are among the most common cancer types,and early detection is paramount to improve their management.Cell-free DNA(cfDNA)liquid biopsy raises significant hopes for non-invasive early detection.AIM To describe current applications of this technology for gastrointestinal cancer detection and screening.METHODS A systematic review of the literature was performed across the PubMed database.Articles reporting the use of cfDNA liquid biopsy in the screening or diagnosis of gastrointestinal cancers were included in the analysis.RESULTS A total of 263 articles were screened for eligibility,of which 13 articles were included.Studies investigated colorectal cancer(5 studies),pancreatic cancer(2 studies),hepatocellular carcinoma(3 studies),and multi-cancer detection(3 studies),including gastric,oesophageal,or bile duct cancer,representing a total of 4824 patients.Test sensitivities ranged from 71% to 100%,and specificities ranged from 67.4% to 100%.Pre-cancerous lesions detection was less performant with a sensitivity of 16.9% and a 100% specificity in one study.Another study using a large biobank demonstrated a 94.9% sensitivity in detecting cancer up to 4 years before clinical symptoms,with a 61% accuracy in tissue-of-origin identification.CONCLUSION cfDNA liquid biopsy seems capable of detecting gastrointestinal cancers at an early stage of development in a non-invasive and repeatable manner and screening simultaneously for multiple cancer types in a single blood sample.Further trials in clinically relevant settings are required to determine the exact place of this technology in gastrointestinal cancer screening and diagnosis strategies.

Circulating tumor DNA in liquid biopsy: Current diagnostic limitation

With the rapid development of science and technology,cell-free DNA(cfDNA)is rapidly becoming an important biomarker for tumor diagnosis,monitoring and prognosis,and this cfDNA-based liquid biopsy technology has great potential to become an important part of precision medicine.cfDNA is the total amount of free DNA in the systemic circulation,including DNA fragments derived from tumor cells and all other somatic cells.Tumor cells release fragments of DNA into the bloodstream,and this source of cfDNA is called circulating tumor DNA(ctDNA).cfDNA detection has become a major focus in the field of tumor research in recent years,which provides a new opportunity for non-invasive diagnosis and prognosis of cancer.In this paper,we discuss the limitations of the study on the origin and dynamics analysis of ctDNA,and how to solve these problems in the future.Although the future faces major challenges,it also con-tains great potential.

Liquid biopsy of gastric cancer patients:Circulating tumor cells and cell-free nucleic acids

To improve the clinical outcomes of cancer patients, early detection and accurate monitoring of diseases are necessary. Numerous genetic and epigenetic alterations contribute to oncogenesis and cancer progression, and analyses of these changes have been increasingly utilized for diagnostic, prognostic and therapeutic purposes in malignant diseases including gastric cancer (GC). Surgical and/or biopsy specimens are generally used to understand the tumor-associated alterations; however, those approaches cannot always be performed because of their invasive characteristics and may fail to reflect current tumor dynamics and drug sensitivities, which may change during the therapeutic process. Therefore, the importance of developing a non-invasive biomarker with the ability to monitor real-time tumor dynamics should be emphasized. This concept, so called “liquid biopsy”, would provide an ideal therapeutic strategy for an individual cancer patient and would facilitate the development of “tailor-made” cancer management programs. In the blood of cancer patients, the presence and potent utilities of circulating tumor cells (CTCs) and cell-free nucleic acids (cfNAs) such as DNA, mRNA and microRNA have been recognized, and their clinical relevance is attracting considerable attention. In this review, we discuss recent developments in this research field as well as the relevance and future perspectives of CTCs and cfNAs in cancer patients, especially focusing on GC.

Role of different examination methods in colorectal cancer screening:Insights and future directions

Colorectal cancer is a malignant tumor with the third and second highest incidence and mortality rates worldwide,and its mortality rate is increasing annually.Colorectal cancer evolves gradually over a long period of time.The evolving process from colorectal adenoma to colorectal cancer takes approximately 10-15 years,providing a sufficiently long"window period"for early screening and diagnosis of colorectal cancer.The recurrence and mortality rates can be controlled at a low level with an early intervention.Metaxas et al summarized existing screening methods and their applicable scope in a recent publication.Moreover,they provide suggestions on how to improve adherence.This editorial provides a commentary on their article and discuss the roles of different screening methods in the early screening of colorectal cancer.

The promise of liquid biopsy in cancer:a clinical perspective

The clinical utility of liquid biopsy in cancer treatment will increase as circulating tumor cells （CTCs） analysis move from the enumeration to the real-time measurement of tumor characteristics. Intratumor heterogeneity is becoming increasingly recognized as a major drawback to the shift to personalized medicine. Spatial and temporal heterogeneity might be reflected by the serial assessment of CTCs. Indeed, the developing technologies for CTCs analysis now allow digital genomic and next- generation sequencing approaches, able to differentiate molecular subtypes of the disease and to monitor genetic variation over time. The liquid biopsy of cancer might offer a real-time assessment of tumor biology, providing the opportunity to serially evaluate patients most likely to benefit from targeted drugs based on a dynamic characterization of the disease at the molecular level. Mthough hurdles remain before liquid biopsy is seen in routine clinical practice, the information derived from CTCs may facilitate the real-time identification of actionable mutations in cancer leading the way toward personalized medicine.

Liquid biopsy approach to pancreatic cancer

Pancreatic cancer(PC)continues to pose a major clinical challenge.There has been little improvement in patient survival over the past few decades,and it is projected to become the second leading cause of cancer mortality by 2030.The dismal 5-year survival rate of less than 10%after the diagnosis is attributable to the lack of early symptoms,the absence of specific biomarkers for an early diagnosis,and the inadequacy of available chemotherapies.Most patients are diagnosed when the disease has already metastasized and cannot be treated.Cancer interception is vital,actively intervening in the malignization process before the development of a full-blown advanced tumor.An early diagnosis of PC has a dramatic impact on the survival of patients,and improved techniques are urgently needed to detect and evaluate this disease at an early stage.It is difficult to obtain tissue biopsies from the pancreas due to its anatomical position;however,liquid biopsies are readily available and can provide useful information for the diagnosis,prognosis,stratification,and follow-up of patients with PC and for the design of individually tailored treatments.The aim of this review was to provide an update of the latest advances in knowledge on the application of carbohydrates,proteins,cell-free nucleic acids,circulating tumor cells,metabo-lome compounds,exosomes,and platelets in blood as potential biomarkers for PC,focusing on their clinical relevance and potential for improving patient outcomes.

Mutations in epigenetic regulator KMT2C detected by liquid biopsy are associated with worse survival in prostate cancer patients

Background:KMT2(lysine methyltransferase)family enzymes are epigenetic regulators that activate gene transcription.KMT2C is mainly involved in enhancer-associated H3K4me1,and is also one of the top mutated genes in cancer(6.6%in pan-cancer).Currently,the clinical significance of KMT2C mutations in prostate cancer is understudied.Methods:We included 221 prostate cancer patients diagnosed between 2014 and 2021 in West China Hospital of Sichuan University with cell-free DNA-based liquid biopsy test results in this study.We investigated the association between KMT2C mutations,other mutations,and pathways.Furthermore,we evaluated the prognostic value of KMT2C mutations,measured by overall survival(OS)and castration resistance-free survival(CRFS).Also,we explored the prognostic value of KMT2C mutations in different patient subgroups.Lastly,we investigated the predictive value of KMT2C mutations in individuals receiving conventional combined anti-androgen blockade(CAB)and abiraterone(ABI)as measured by PSA progression-free survival(PSA-PFS).Results:The KMT2C mutation rate in this cohort is 7.24%(16/221).KMT2C-mutated patients showed worse survival than KMT2C-wild type(WT)patients regarding both CRFS and OS(CRFS:mutated:9.9 vs.WT:22.0 months,p=0.015;OS:mutated:71.9 vs.WT 137.4 months,p=0.012).KMT2C mutations were also an independent risk factor in OS[hazard ratio:3.815(1.461,9.96),p=0.006]in multivariate analyses.Additionally,we explored the association of KMT2C mutations with other genes.This showed that KMT2C mutations were associated with Serine/Threonine-Protein Kinase 11(STK11,p=0.004)and Catenin Beta 1(CTNNB1,p=0.008)mutations.In the CAB treatment,KMT2C-mutated patients had a significantly shorter PSA-PFS compared to KMT2C-WT patients.(PSA-PFS:mutated:9.9 vs.WT:17.6 months,p=0.014).Moreover,KMT2C mutations could effectively predict shorter PSA-PFS in 10 out of 23 subgroups and exhibited a strong trend in the remaining subgroups.Conclusions:KMT2C-mutated patients showed worse survival compared to KMT2C-WT patients in terms of both CRFS and OS,and KMT2C mutations were associated with STK11 and CTNNB1 mutations.Furthermore,KMT2C mutations indicated rapid progression during CAB therapy and could serve as a potential biomarker to predict therapeutic response in prostate cancer.

Liquid biopsy in ovarian cancer:Catching the silent killer before it strikes

Epithelial ovarian cancer(EOC)is the most lethal gynaecological malignancy in the western world.The majority of women presenting with the disease are asymptomatic and it has been dubbed the“silent killer”.To date there is no effective minimally invasive method of stratifying those with the disease or screening for the disease in the general population.Recent molecular and pathological discoveries,along with the advancement of scientific technology,means there is a real possibility of having disease-specific liquid biopsies available within the clinical environment in the near future.In this review we discuss these discoveries,particularly in relation to the most common and aggressive form of EOC,and their role in making this possibility a reality.

Exosomes:Key tools for cancer liquid biopsy

Precision medicine is based on the identification of biomarkers of tumor development and progression.Liquid biopsy is at the forefront of the ability to gather diagnostic and prognostic information on tumors,as it can be noninvasively performed prior or during treatment.Liquid biopsy mostly utilizes circulating tumor cells,or free DNA,but also exosomes.The latter are nanovesicles secreted by most cell types,found in any body fluid that deliver proteins,nucleic acids and lipids to nearby and distant cells with a unique homing ability.Exosomes function in signalling between the tumor microenvironment and the rest of the body,promoting metastasis,immune remodelling and drug resistance.Exosomes are emerging as a key tool in precision medicine for cancer liquid biopsy,as they efficiently preserve their biomarker cargo.Moreover,exosomes strongly resemble the parental cell,which can help in assessing the oxidative and metabolic state of the donor cell.In this respect,exosomes represent one of the most promising new tools to fight cancer.This review will discuss the clinical applications of profiling exosomal proteins and lipids by high-throughput proteomics and metabolomics,and nucleic acids by next generation sequencing,as well as how this may allow cancer diagnosis,therapy response monitoring and recurrence detection.

Analysis of microsatellite instability in stool DNA of patients with colorectal cancer using denaturing high performance liquid chromatography

AIM： To evaluate the usefulness of denaturing high performance liquid chromatography （DHPLC） for analyzing microsatellite instability （MSI） status in stool DNA of patients with colorectal cancer. METHODS： A total of 80 cancer tissues from patients with primary sporadic colorectal tumor （proximal cancer： 27, distal cancer： 53） and matched stool （which were employed for comparison with the tissues） were analyzed for MSI status in BAT 26. DNA samples extracted from stool were evaluated by nested polymerase chain reaction （PCR） and DHPLC for MSI analysis. RESULTS： Six cases （7.5%） of MSI were identified in BAT 26 from 80 cancer tissues. All the stool DNA samples from patients whose cancer tissue showed IVlSI also displayed MSI in BAT 26. CONCLUSION： As MSI is one of the established fecal DNA markers to screen colorectal cancer, we propose to use DHPLC for the IVlSI analysis in fecal DNA.

Overview of microRNAs as liquid biopsy biomarkers for colorectal cancer sub-type profiling and chemoresistance

Colorectal cancer(CRC)is the third most common cancer worldwide.It has also been demonstrated that over the last ten years the incidence of CRC among younger people below the age of 50 is also increasing.Screening for colorectal cancer is of utmost importance;the rationale behind screening is to target the malignancy and reduce the incidence and mortality of the disease.Diagnostic methods to screen for incidence or relapse are therefore a requisite to detect cancer as early as possible.Scientific findings demonstrate that many deaths are due to lack of screening and therefore early identification will lead to greater survivability.In colorectal cancer,diagnostic tests include liquid biopsy biomarkers.Since the discovery of microRNAs(miRNAs),many studies have demonstrated the relationship between miRNAs and the various sub-types of CRC.Several miRNAs have been identified after analysing serum or plasma samples in patients,and such miRNAs were found to be significantly dysregulated.Such findings place the possibility of miRNAs to be at the epicentre of novel diagnostic techniques for CRC identification and sub-type stratification,including other characteristics associated with CRC development such as patient prognosis.The following review serves to underline the latest findings for miRNAs with such potential for routine diagnostic employment in CRC diagnostics and treatments.

Liquid biopsy in patients with pancreatic cancer: Circulating tumor cells and cell-free nucleic acids

Despite recent advances in surgical techniques and perioperative management, the prognosis of pancreatic cancer(PCa) remains extremely poor. To provide optimal treatment for each patient with Pca, superior biomarkers are urgently needed in all phases of management from early detection to staging, treatment monitoring, and prognosis. In the blood of patients with cancer, circulating tumor cells(CTCs) and cell-free nucleic acids(cf NAs), such as DNA, m RNA, and noncoding RNA have been recognized. In the recent years, their presence in the blood has encouraged researchers to investigate their potential use as novel blood biomarkers, and numerous studies have demonstrated their potential clinical utility as a biomarker for certain types of cancer. This concept, called "liquid biopsy" has been focused on as a less invasive, alternative approach to cancer tissue biopsy for obtaining genetic and epigenetic aberrations that contribute to oncogenesis and cancer progression. In this article, we review the available literature on CTCs and cfN As in patients with cancer, particularly focusing on PCa, and discuss future perspectives in this field.