Detection of methylated septin 9 in tissue and plasma of colorectal patients with neoplasia and the relationship to the amount of circulating cell-free DNA

Advances in the diagnosis of colorectal cancer: the application of molecular biomarkers and imaging techniques: a literature review

Background

Following neoplasms of the lung and breast, colorectal cancer (CRC) is the third most frequent malignancy globally. Screening for CRC at the age of 50 years is strongly encouraged for prompt earlier diagnosis owing to prognoses being greatly correlated with time of detection and cancer staging.

Aim

This review aimed to elucidate the most recent advancements in the detection of CRC, with an emphasis on the latest innovations in diagnostic molecular biomarkers in conjunction with radiological imaging alongside stool-based tests for CRC screening.

Methods

A comprehensive review of the literature was performed, focusing on specific terms in different electronic databases, including that of PubMed/MEDLINE. Keywords pertaining to "colorectal cancer," "diagnosis," "screening," "imaging," and "biomarkers," among others, were employed in the search strategy. Articles screened and evaluated were deemed relevant to the study aim and were presented in the medium of the English language.

Results

There have been several innovations in the diagnostics and identification of CRC. These generally comprise molecular biomarkers, currently being studied for suitability in disease detection. Examples of these include genetic, epigenetic, and protein biomarkers. Concurrently, recent developments in CRC diagnostics highlight the advancements made in radiological imaging that offer precise insights on tumor biology in addition to morphological information. Combining these with statistical methodologies will increase the sensitivity and specificity of CRC diagnostics. However, putting these strategies into reality is hampered by several issues.

Conclusion

Progress in diagnostic technology alongside the identification of a few prognostic predictive molecular biomarkers suggested great promise for prompt detection and management of CRC. This clearly necessitates further efforts to learn more in this specific sector.

The common bisulfite-conversion-based techniques to analyze DNA methylation in human cancers

DNA methylation is an important molecular modification that plays a key role in the expression of cancer genes. Evaluation of epigenetic changes, hypomethylation and hypermethylation, in specific genes are applied for cancer diagnosis. Numerous studies have concentrated on describing DNA methylation patterns as biomarkers for cancer diagnosis monitoring and predicting response to cancer therapy. Various techniques for detecting DNA methylation status in cancers are based on sodium bisulfite treatment. According to the application of these methods in research and clinical studies, they have a number of advantages and disadvantages. The current review highlights sodium bisulfite treatment-based techniques, as well as, the advantages, drawbacks, and applications of these methods in the evaluation of human cancers.

DNA methylation modulates epigenetic regulation in colorectal cancer diagnosis, prognosis and precision medicine

Colorectal cancer (CRC) is a multifaceted disease influenced by the interplay of genetic and environmental factors. The clinical heterogeneity of CRC cannot be attributed exclusively to genetic diversity and environmental exposures, and epigenetic markers, especially DNA methylation, play a critical role as key molecular markers of cancer. This review compiles a comprehensive body of evidence underscoring the significant involvement of DNA methylation modifications in the pathogenesis of CRC. Moreover, this review explores the potential utility of DNA methylation in cancer diagnosis, prognostics, assessment of disease activity, and prediction of drug responses. Recognizing the impact of DNA methylation will enhance the ability to identify distinct CRC subtypes, paving the way for personalized treatment strategies and advancing precision medicine in the management of CRC.

Advances in blood DNA methylation-based assay for colorectal cancer early detection: a systematic updated review

Aim

A systematic review was conducted to summarize the methylated circulating tumor DNA (ctDNA) markers reported over the last decade for early detection of colorectal cancer (CRC) and to identify the main technical challenges that are impeding their clinical implementation.

Background

CRC is a major cause of cancer deaths worldwide, but early detection is key for successful treatment. Non-invasive methods such as methylated ctDNA testing show promise for improving detection and monitoring of CRC.

Methods

A comprehensive search was performed using Web of Science, PubMed, and Scopus up to December 30, 2023, limited to articles published in the last 10 years (after 2012), while including advanced adenoma/stage 0 or stage I/II samples in biomarker validation.

Results

After identifying 694 articles, removing duplicates and screening titles, abstracts, and full texts, a total of 62 articles were found to meet the inclusion criteria. Among the single biomarkers, MYO1-G, SEPT9, SDC2, and JAM3 revealed the highest sensitivity for polyps and stage I/II CRC. For multi-biomarkers with suitable sensitivity, combinations of SFRP1, SFRP2, SDC2, PRIMA1, or ALX4, BMP3, NPTX2, RARB, SDC2, SEPT9, VIM or ZFHX4, ZNF334, ELOVL2, UNC5C, LOC146880, SFMBT2, GFRA1 were identified for polyps and stage I/II CRC.

Conclusion

Enhancing sensitivity and specificity of molecular screening methods is crucial for improving CRC detection. Identifying a select few valuable biomarkers is key to reducing costs, despite challenges posed by low ctDNA levels in plasma, particularly in early-stage cancers.

Effects of obesity, and of weight loss following bariatric surgery, on methylation of DNA from the rectal mucosa and in cell-free DNA from blood

BACKGROUND

DNA methylation is an epigenetic mechanism through which environmental factors including nutrition and inflammation influence health. Obesity is a major modifiable risk factor for many common diseases including cardiovascular diseases and cancer. In particular, obesity-induced inflammation resulting from aberrantly-methylated inflammatory genes may drive risk of several non-communicable diseases including colorectal cancer (CRC). This study is the first to investigate the effects of weight loss induced by bariatric surgery (BS) on DNA methylation in the rectum and in cell-free DNA (cfDNA) from blood.

SUBJECTS AND METHODS

DNA methylation was quantified in rectal mucosal biopsies and cfDNA from serum of 28 participants with obesity before and 6 months after BS, as well as in 12 participants without obesity (control group) matched for age and sex from the Biomarkers Of Colorectal cancer After Bariatric Surgery (BOCABS) Study. DNA methylation of LEP, IL6, POMC, LINE1, MAPK7 and COX2 was quantified by pyrosequencing.

RESULTS

BMI decreased significantly from 41.8 kg/m2 pre-surgery to 32.3 kg/m2 at 6 months after BS. Compared with the control group, obesity was associated with lower LEP methylation in both the rectal mucosa and in cfDNA from serum. BS normalised LEP methylation in DNA from the rectal mucosa but not in cfDNA. BS decreased methylation of some CpG sites of LINE1 in the rectal mucosal DNA and in cfDNA to levels comparable with those in participants without obesity. Methylation of POMC in rectal mucosal DNA was normalised at 6 months after BS.

CONCLUSION

BS reversed LINE1, POMC and LEP methylation in the rectal mucosa of patients with obesity to levels similar to those in individuals without obesity. These findings support current evidence of effects of BS-induced weight loss on reversibility of DNA methylation in other tissues. The DNA methylation changes in the rectal mucosa shows promise as a biomarker for objective assessment of effects of weight loss interventions on risk of cancer and other diseases.

Complete Blood Count Alterations Prior to the Diagnosis of Colorectal Cancer May Help in the Detection of Synchronous Liver Metastases

Background and Aims: Colorectal cancer (CRC) represents 10% of all cancers worldwide with the highest incidence in developed countries; its incidence is also increasing in middle- and low-income countries. Population screening programs facilitate early diagnosis of the disease. When the diagnosis is carried out in advanced stages, approximately 80% of patients with liver metastases (LM) are considered unresectable at the time of diagnosis. In our study, variations in blood counts prior to CRC diagnosis were analyzed to assess whether they could be useful in identifying smaller, more manageable metastases at earlier stages for more effective treatment. Methods: A study was carried out using complete blood counts (CBCs) from CRC patients, obtained from primary health centers and the La Ribera University Hospital within La Ribera Health Department, Valencian Community, Spain, between July 2012 and September 2020. Data from CRC patients who presented synchronous liver metastasis (CRLM) were compared with those with CRC without LM at diagnosis (CRC patients). Results: Our analysis shows that at least 15 months before CRC diagnosis, a progressive alteration was observed in CBC parameters in both groups. A higher incidence of anemia (p < 0.001) was observed among CRLM patients in the three months prior to CRC diagnosis than in CRC patients showing no LM. Conclusions: A statistically significant deterioration of CBC was observed in patients with advanced-stage CRC and synchronous or early LM (CRLM) in the three months prior to diagnosis. The primary goal of incorporating CBC variations into predictive models is to identify individuals who are at a greater risk of developing metastatic colon cancer, leading to early diagnosis. Our research improves these models by highlighting a more pronounced and rapid decline in hemoglobin levels among CRLM patients. Identification of metastases at an earlier stage when they are smaller, more manageable, and more amenable to treatment may be a valuable tool to prevent their further progression.

Health Economic Evidence and Modeling Challenges for Liquid Biopsy Assays in Cancer Management: A Systematic Literature Review

BACKGROUND

Cancer-derived material circulating in the bloodstream and other bodily fluids, referred to as liquid biopsies (LBs), has become an appealing adjunct or alternative to tissue biopsies, showing vital promise in several clinical applications.

PURPOSE

A systematic literature review was conducted to (1) summarize the current health economic evidence for LB assays and (2) identify and analyze the studies addressed or reported on the challenges of health economic modeling in precision medicine.

METHODS

Relevant studies were identified in the EMBASE, MEDLINE, Cochrane Library, EconLit, and the University of Melbourne Full Text Journal databases from 1 January 2013 to 16 September 2022. Included papers were selected if they were economic evaluations and/or budget impact analyses.

RESULTS

A total of 24 studies were included and analyzed, with the majority being full economic evaluations (n = 19, 79.2%). Four studies (16.7%) were health and budget impact analyses, and one study (4.1%) incorporated both an economic evaluation and a budget impact analysis. Cohort-level modeling techniques were the most common approach (n = 16; 80%). LB technologies were cost-effective in 15 studies (75%) considering different biomarkers, cancer types and stages, and economic analyses. These studies evaluated LBs for screening and early detection (66.7%), treatment selection (26.7%), and monitoring treatment response (6.6%). Budget impact analysis results were varied among included studies, with the majority of studies (n = 4; 80%) reporting either cost savings, minimal, or modest budget impact, while one study (20%) reported LBs as an efficient strategy. The reviewed studies often inadequately reported or addressed modeling challenges, such as patient-level processes, the combination of tests and treatments, preferences, and uncertainty.

CONCLUSION

LBs could provide a cost-effective approach for treatment selection in lung cancer and aid in the screening and early detection of other cancers, including colorectal, gastric, breast, and brain cancers. This is in comparison with various alternatives, such as the standard of care (SOC) and no screening scenario. However, it is important to mention that in some comparisons, LBs were used in combination with SOC instead of replacing it. Importantly, few studies have pointed toward LBs' cost-effectiveness for monitoring treatment response. Most health and budget impact analyses, especially those focused on lung cancer, suggest potential cost savings or a minimal-to-moderate budget impact. Nevertheless, additional research is needed to ascertain their effectiveness across various stages of lung and colorectal cancer, as well as to address potential modeling challenges.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022307939.

Progress in the field of noninvasive diagnostics for colorectal cancer: a systematic review for the accuracy of blood-based biomarkers for detection of advanced pre-cancerous lesions

BACKGROUND

Early detection of pre-cancerous adenomas through screening can reduce colorectal cancer (CRC) incidence. Fecal immunochemical tests are commonly used, but have limited sensitivity for pre-cancerous lesions. Blood-based screening may improve test sensitivity. This systematic review and meta-analysis was conducted to evaluate the accuracy of blood-based biomarkers for detection of advanced pre-cancerous lesions.

RESEARCH DESIGN AND METHODS

We present the accuracy of blood-based biomarkers for the detection of advanced pre-cancerous lesions. EMBASE, Web of Science and PubMed databases were searched, with study populations limited to adults diagnosed with advanced pre-cancerous lesions at colonoscopy, who had a blood-based biomarker test analyzed with reports of sensitivity and specificity.

RESULTS

69 studies were identified, which assessed 133 unique biomarkers sets. The best performing test was a panel of 6 miRNAs, with a sensitivity of 95% and specificity of 90% for advanced pre-cancerous lesions. Only 6 biomarkers demonstrated sensitivity ≥ 50% and specificity ≥ 90% for the detection of advanced pre-cancerous lesions.

CONCLUSION

Many different blood-based biomarkers have been assessed for detection of advanced pre-cancerous lesions, but few have progressed beyond the discovery stage. While some biomarkers have reported high sensitivity and specificity, larger prospective studies in unbiased intended-use screening populations are required for validation.

SEPT9 Expression in Hepatic Nodules: An Immunohistochemical Study of Hepatocellular Neoplasm and Metastasis

The methylated SEPT9 DNA ( mSEPT9 ) in plasma is a US Food and Drug Administration (FDA)-approved screening biomarker in colorectal cancer and is emerging as a promising diagnostic and prognostic biomarker in hepatocellular carcinoma (HCC). We evaluated the SEPT9 protein expression by immunohistochemistry (IHC) in various hepatic tumors from 164 hepatectomies and explants. Cases diagnosed as HCC (n=68), hepatocellular adenoma (n=31), dysplastic nodule (n=24), and metastasis (n=41) were retrieved. SEPT9 stain was performed on representative tissue blocks showing tumor/liver interface. For HCC, archived IHC (SATB2, CK19, CDX2, CK20, and CDH17) slides were also reviewed. The findings were correlated with demographics, risk factors, tumor size, alpha fetoprotein levels at diagnosis, T stage and oncologic outcomes, with significance defined as P <0.05. Percentage of SEPT9 positivity differed significantly among hepatocellular adenoma (3%), dysplastic nodule (0%), HCC (32%), and metastasis (83%, P <0.001). Compared with patients with SEPT9- HCC, those with SEPT9+ HCC were older (70 vs. 63 y, P =0.01). The extent of SEPT9 staining correlated with age ( rs =0.31, P =0.01), tumor grade ( rs =0.30, P =0.01), and extent of SATB2 staining ( rs =0.28, P =0.02). No associations were found between SEPT9 staining and tumor size, T stage, risk factors, CK19, CDX2, CK20, or CDH17 expression, alpha fetoprotein levels at diagnosis, METAVIR fibrosis stage, and oncologic outcome in the HCC cohort. SEPT9 is likely implicated in liver carcinogenesis in a HCC subset. Similar to mSEPT9 DNA measurement in liquid biopsies, SEPT9 staining by IHC may prove helpful as an adjunct diagnostic biomarker with potential prognostic ramifications.

Aberrant circulating tumor DNA methylation and exosomal microRNA biomarkers for early detection of colorectal cancer

INTRODUCTION

Colorectal cancer (CRC) became the third most commonly diagnosed malignancy and the second leading cause of cancer death in 2020. However, the rates of early screening and early diagnosis for CRC remain unsatisfactory. Thus, it is essential to explore the initiating factors of CRC and strategies for its early diagnosis. Research progress in liquid biopsy has led to the finding that circulating tumor-derived DNA (ctDNA) and exosomes play vital roles in early detection of CRC. THE APPLICATIONS OF LIQUID BIOPSY FOR EARLY DETECTION OF COLORECTAL CANCER: Moreover, the increased understanding of epigenetics has highlighted the role of ctDNA methylation in CRC carcinogenesis, and the detection of aberrant ctDNA methylation markers is a feasible strategy for diagnosis of early-stage CRC. Among exosomal markers, microRNAs (miRNAs) are abundant and are the most researched. Upregulated or downregulated expression of exosome-derived miRNAs can indicate the occurrence of early-stage CRC.

FUTURE PERSPECTIVE

The current research progress on aberrant ctDNA methylation and tumor exosomal miRNA biomarkers in early detection of CRC is summarized in this review, and the advantages and shortcomings of the methods are discussed.

Computational Simulation of Colorectal Cancer Biomarker Particle Mobility in a 3D Model

Even though some methods for the detection of colorectal cancer have been used clinically, most of the techniques used do not consider the in situ detection of colorectal cancer (CRC) biomarkers, which would favor in vivo real-time monitoring of the carcinogenesis process and consequent studies of the disease. In order to give a scientific and computational framework ideal for the evaluation of diagnosis techniques based on the early detection of biomarker molecules modeled as spherical particles from the computational point of view, a computational representation of the rectum, stool and biomarker particles was developed. As consequence of the transport of stool, there was a displacement of CRC biomarker particles that entered the system as a result of the cellular apoptosis processes in polyps with a length lower than 1 cm, reaching a maximum velocity of 3.47×10-3 m/s. The biomarkers studied showed trajectories distant to regions of the polyp of origin in 1 min of simulation. The research results show that the biomarker particles for CRC respond to the variations in the movements of the stool with trajectories and speeds that depend on the location of the injury, which will allow locating the regions with the highest possibilities of catching particles through in situ measurement instruments in the future.

Using Circulating Tumor DNA as a Novel Biomarker to Screen and Diagnose Colorectal Cancer: A Meta-Analysis

(1) Background: Circulating tumor DNA (ctDNA) has emerged as a promising biomarker for many kinds of tumors. However, whether ctDNA could be an accurate diagnostic biomarker in colorectal cancer (CRC) remains to be clarified. The aim of this study was to evaluate the diagnostic accuracy of ctDNA in CRC. (2) Methods: PubMed, Web of Science, and Cochrane databases were searched to identify studies reporting the use of ctDNA to screen and diagnose CRC, and all relevant studies published until October 2022 were enrolled for our analysis. These studies were divided into three primer subgroups: the subgroup of quantitative or qualitative analysis of ctDNA and the subgroup of septin9 (SEPT9) methylation assay. (3) Results: A total of 79 qualified articles with 25,240 subjects were incorporated into our meta-analysis. For quantitative studies, the combined sensitivity (SEN), specificity (SPE), and diagnostic odds ratio (DOR) were 0.723 (95% CI: 0.623-0.803), 0.920 (95% CI: 0.827-0.966), and 23.305 (95% CI: 9.378-57.906), respectively, yielding an AUC of 0.860. The corresponding values for qualitative studies were 0.610 (95% CI: 0.566-0.651), 0.891 (95% CI: 0.878-0.909), 12.569 (95% CI: 9.969-15.848), and 0.823, respectively. Detection of SEPT9 methylation depicted an AUC of 0.879, with an SEN of 0.679 (95% CI: 0.622-0.732), an SPE of 0.903 (95% CI: 0.878-0.923), and a DOR of 20.121 (95% CI:14.404-28.106), respectively. (4) Conclusion: Blood-based ctDNA assay would be a potential novel biomarker for CRC screening and diagnosis. Specifically, quantitative analysis of ctDNA or qualitative analysis of SEPT9 methylation exhibited satisfying diagnostic efficiency. Larger sample studies are needed to further confirm our conclusions and to make the ctDNA approach more sensitive and specific.

Extracellular Nucleic Acids in the Diagnosis and Progression of Colorectal Cancer

Colorectal cancer (CRC) is the 3rd most common malignant neoplasm worldwide, with more than two million new cases diagnosed yearly. Despite increasing efforts in screening, many cases are still diagnosed at a late stage, when mortality is high. This paper briefly reviews known genetic causes of CRC (distinguishing between sporadic and familial forms) and discusses potential and confirmed nucleic acid biomarkers obtainable from liquid biopsies, classified by their molecular features, focusing on clinical relevance. We comment on advantageous aspects such as better patient compliance due to blood sampling being minimally invasive, the possibility to monitor mutation characteristics of sporadic and hereditary CRC in a disease showing genetic heterogeneity, and using up- or down-regulated circulating RNA markers to reveal metastasis or disease recurrence. Current difficulties and thoughts on some possible future directions are also discussed. We explore current evidence in the field pointing towards the introduction of personalized CRC management.

Seven DNA Methylation Biomarker Prediction Models for Monitoring the Malignant Progression From Advanced Adenoma to Colorectal Cancer

Advanced adenoma (AA) holds a significantly increased risk for progression to colorectal cancer (CRC), and we developed a noninvasive DNA methylation prediction model to monitor the risk of AA progression to CRC. We analyzed the differential methylation markers between 53 normal mucosa and 138 CRC tissues, as well as those in cfDNA (cell-free DNA) between 59 AA and 68 early-stage CRC patients. We screened the overlapping markers between tissue DNA and cfDNA for model variables and optimized the selected variables. Then, we established a cfDNA methylation prediction model (SDMBP model) containing seven methylation markers that can effectively discriminate early-stage CRC and AA in the training and validation cohorts, and the AUC (area under the curve) reached 0.979 and 0.918, respectively. Our model also reached high precision (AUC=0.938) in detecting advanced CRC (stage III/IV) and presented better performance than serum CEA and CA199 in screening CRC. The cd-score of the SDMBP model could also robustly predict the TNM stage of CRC. Overall, our SDMBP model can monitor the malignant progression from AA to CRC, and may provide a noninvasive monitoring method for high-risk populations with AA.

Epigenome-Wide DNA Methylation Profiling in Colorectal Cancer and Normal Adjacent Colon Using Infinium Human Methylation 450K

The aims were to profile the DNA methylation in colorectal cancer (CRC) and to explore cancer-specific methylation biomarkers. Fifty-four pairs of CRCs and the adjacent normal tissues were subjected to Infinium Human Methylation 450K assay and analysed using ChAMP R package. A total of 26,093 differentially methylated probes were identified, which represent 6156 genes; 650 probes were hypermethylated, and 25,443 were hypomethylated. Hypermethylated sites were common in CpG islands, while hypomethylated sites were in open sea. Most of the hypermethylated genes were associated with pathways in cancer, while the hypomethylated genes were involved in the PI3K-AKT signalling pathway. Among the identified differentially methylated probes, we found evidence of four potential probes in CRCs versus adjacent normal; HOXA2 cg06786372, OPLAH cg17301223, cg15638338, and TRIM31 cg02583465 that could serve as a new biomarker in CRC since these probes were aberrantly methylated in CRC as well as involved in the progression of CRC. Furthermore, we revealed the potential of promoter methylation ADHFE1 cg18065361 in differentiating the CRC from normal colonic tissue from the integrated analysis. In conclusion, aberrant DNA methylation is significantly involved in CRC pathogenesis and is associated with gene silencing. This study reports several potential important methylated genes in CRC and, therefore, merit further validation as novel candidate biomarker genes in CRC.

Novel Diagnostic Biomarkers in Colorectal Cancer

Colorectal cancer (CRC) is still a leading cause of cancer death worldwide. Less than half of cases are diagnosed when the cancer is locally advanced. CRC is a heterogenous disease associated with a number of genetic or somatic mutations. Diagnostic markers are used for risk stratification and early detection, which might prolong overall survival. Nowadays, the widespread use of semi-invasive endoscopic methods and feacal blood tests characterised by suboptimal accuracy of diagnostic results has led to the detection of cases at later stages. New molecular noninvasive tests based on the detection of CRC alterations seem to be more sensitive and specific then the current methods. Therefore, research aiming at identifying molecular markers, such as DNA, RNA and proteins, would improve survival rates and contribute to the development of personalized medicine. The identification of “ideal” diagnostic biomarkers, having high sensitivity and specificity, being safe, cheap and easy to measure, remains a challenge. The purpose of this review is to discuss recent advances in novel diagnostic biomarkers for tumor tissue, blood and stool samples in CRC patients.

Identification and Validation of Esophageal Squamous Cell Carcinoma Targets for Fluorescence Molecular Endoscopy

Dysplasia and intramucosal esophageal squamous cell carcinoma (ESCC) frequently go unnoticed with white-light endoscopy and, therefore, progress to invasive tumors. If suitable targets are available, fluorescence molecular endoscopy might be promising to improve early detection. Microarray expression data of patient-derived normal esophagus (n = 120) and ESCC samples (n = 118) were analyzed by functional genomic mRNA (FGmRNA) profiling to predict target upregulation on protein levels. The predicted top 60 upregulated genes were prioritized based on literature and immunohistochemistry (IHC) validation to select the most promising targets for fluorescent imaging. By IHC, GLUT1 showed significantly higher expression in ESCC tissue (30 patients) compared to the normal esophagus adjacent to the tumor (27 patients) (p < 0.001). Ex vivo imaging of GLUT1 with the 2-DG 800CW tracer showed that the mean fluorescence intensity in ESCC (n = 17) and high-grade dysplasia (HGD, n = 13) is higher (p < 0.05) compared to that in low-grade dysplasia (LGD) (n = 7) and to the normal esophagus adjacent to the tumor (n = 5). The sensitivity and specificity of 2-DG 800CW to detect HGD and ESCC is 80% and 83%, respectively (ROC = 0.85). We identified and validated GLUT1 as a promising molecular imaging target and demonstrated that fluorescent imaging after topical application of 2-DG 800CW can differentiate HGD and ESCC from LGD and normal esophagus.

[Value of plasma SEPTIN9 methylation detection for diagnosis and predicting radiosensitivity of esophageal carcinoma]

OBJECTIVE

To investigate the value of plasma mSEPT9 detection in the diagnosis and prediction of radiosensitivity of esophageal carcinoma.

METHODS

This study was conducted in 72 patients with esophageal cancer who received radical radiotherapy in the Department of Radiotherapy of First Affiliated Hospital of Bengbu Medical College between January, 2019 and December, 2020.Plasma mSEPT9 of the patients were examined with PCR before and after radiotherapy, with 20 healthy subjects from the physical examination center as the controls.The receiver operating characteristic curve (ROC) was used to assess the value of mSEPT9 in diagnosis of esophageal cancer, and the correlation between mSEPT9 and clinicopathological characteristics of the patients was analyzed.According to their response to radiotherapy, the patients were divided into radiosensitive group and insensitive group, and their plasma mSEPT9 levels were compared before radiotherapy.All the patients were observed for dynamic changes of mSEPT9 levels after radiotherapy to analyze the association of mSEPT9 variation with radiosensitivity of the tumors.

RESULTS

The sensitivity and specificity of mSEPT9 for the diagnosis of esophageal carcinoma were 62.5% and 100%, respectively, with an area under the ROC curve of 0.813.Plasma mSEPT9 level was correlated with lymph node metastasis and clinical stages of esophageal carcinoma (P < 0.05), but not with gender, age, invasion site, tumor length, degree of differentiation, or depth of invasion (P > 0.05).The radiosensitive patients had a significantly lower positivity rate for mSEPT9 than the insensitive patients before radiotherapy(53.06% vs 82.61%, P=0.016).In the 72 patients, the positivity rate for mSEPT9 decreased significantly after radiotherapy (30.56% vs 62.5%, P < 0.001); the positivity rate was significantly lowered after radiotherapy in the radiosensitive group (14.29% vs 53.06%, P < 0.001), but the reduction was not significant in the insensitive group (65.22% vs 82.61%, P=0.125).

CONCLUSION

Detection of plasma mSEPT9 level is helpful for diagnosis and prediction of radiosensitivity of esophageal carcinoma.

Methylation profile of colon cancer genes in colorectal precursor lesions and tumor tissue: perspectives for screening

AIMS

Epigenetic alterations of genes involved in colorectal carcinogenesis are likely to be informative biomarkers for early detection. We assessed the methylation profile of a panel of seven colon cancer-related genes comparing normal colon, colorectal cancer (CRC) precursor lesions and cancer tissues from a Brazilian cohort.

METHODS

The cohort comprised 114 CRC patients, including 40 matched normal tissue, 47 patients with adenomas, 33 with serrated polyps and 8 with normal colonic biopsy. DNA methylation status of SEPT9, ALX4, NDRG4, BMP3, APC, p16 and MLH1 was determined by pyrosequencing and correlated with clinicopathological features. Sensitivity, specificity, positive predictive value and negative predictive value were calculated for all genes using cancer endpoint.

RESULTS

The most frequently methylated genes in cancer and in precancer lesions were SEPT9, ALX4, NDRG4, and BMP3, ranging from 55.3 to 95% of the samples. Overall, the frequency of methylation of these four genes in normal colonic tissue was significantly lower as compared to cancer or precursor lesions both in adenoma-carcinoma (p < .001 and p < .050) and serrated (sessile-serrated lesion) (p < .001 and p < .050) pathways. Additionally, sensitivity for the cancer endpoint ranged from 65.6 to 91.8%, and specificity from 17.9 to 62.9% for SEPT9, ALX4, NDRG4, and BMP3 genes. Moreover, the comethylation of ≥4 genes was higher in sessile-serrated lesion (87.5%) and conventional adenomas (78.7%) than in hyperplastic polyps (43.7%) (p = .025) and was significantly associated with proximal cancers (p = .042).

CONCLUSIONS

Our study suggests the DNA methylation can constitute potential biomarkers in CRC screening of Brazilian population.

Methylated circulating tumor DNA as a biomarker for colorectal cancer diagnosis, prognosis, and prediction

Worldwide, colorectal cancer (CRC) is a deadly disease whose death rate ranks second among cancers though its incidence ranks third. Early CRC detection is key and is associated with improved survival outcomes. However, existing tests for CRC diagnosis have several weaknesses thus rendering them inefficient. Moreover, reliable prognostic tests that can predict the overall cancer outcome and recurrence of the disease as well as predictive markers that can assess effectiveness of therapy are still lacking. Thus, shifting to noninvasive liquid biopsy or blood-based biomarkers is vital to improving CRC diagnosis, prognosis, and prediction. Methylated circulating tumor DNA (ctDNA) has gained increased attention as a type of liquid biopsy that is tumor-derived fragmented DNA with epigenetic alterations. Methylated ctDNA are more consistently present in blood of cancer patients as compared to mutated ctDNA. Hence, methylated ctDNA serves as a potential biomarker for CRC that is worth investigating. In this review, we explore what has been reported about methylated ctDNA as a biomarker for CRC diagnosis that can distinguish between CRC patients or those having adenoma and healthy controls as validated specifically through ROC curves. We also examine methylated ctDNA as a biomarker for CRC prognosis and prediction as confirmed through robust statistical analyses. Finally, we discuss the major technical challenges that limits the use of methylated ctDNA for clinical application and suggest possible recommendations to enhance its usage.

Identification of DNA methylation markers for early detection of CRC indicates a role for nervous system-related genes in CRC

Purpose

Colonoscopy and the fecal immunochemical test (FIT) are currently the most widely used screening modalities for colorectal cancer (CRC), however, both with their own limitations. Here we aim to identify and validate stool-based DNA methylation markers for the early detection of CRC and investigate the biological pathways prone to DNA methylation.

Methods

DNA methylation marker discovery was performed using The Cancer Genome Atlas (TCGA) colon adenocarcinoma data set consisting of normal and primary colon adenocarcinoma tissue. The performance of the five best candidate markers and a previously identified marker, NDRG4, was evaluated on tissues and whole stool samples of healthy subjects and CRC patients using quantitative MSP assays. The results were compared and combined with FIT data. Finally, pathway and gene ontology enrichment analyses were performed using ToppFun, GOrilla and clusterProfiler.

Results

GDNF, HAND2, SLC35F3, SNAP91 and SORCS1 were ranked as the best performing markers. Gene combinations of all five markers, NDRG4 and FIT were evaluated to establish the biomarker panel with the highest diagnostic potential, resulting in the identification of GDNF/SNAP91/NDRG4/FIT as the best performing marker panel. Pathway and gene ontology enrichment analyses revealed that genes associated with the nervous system were enriched in the set of best performing CRC-specific biomarkers.

Conclusion

In silico discovery analysis using TCGA-derived data yielded a novel DNA-methylation-based assay for the early detection of CRC, potentially improving current screening modalities. Additionally, nervous system-related pathways were enriched in the identified genes, indicating an epigenetic regulation of neuronal genes in CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01067-9.

Methylated SFRP2 and SDC2 in stool specimens for Colorectal Cancer early detection: A cost-effective strategy for Chinese population

Background: The aim of this study was to evaluate the feasibility of combination of methylated SFRP2 and methylated SDC2 (SpecColon test) in stool specimens for colorectal cancer (CRC) early detection and to optimize the cut-off value of methylated SFRP2 and methylated SDC2. Methods: Approximately 5 g of stool specimen each was collected from 420 subjects (291 in the training cohort and 129 in the validation cohort). Stool DNA was extracted and bisulfite-converted, followed by detection of methylated level of SFRP2 and SDC2. Youden index was employed to determine the cut-off value. Results: The whole operating time for stool SpecColon test takes less than 5 hours. The limit of detection of combination of methylated SFRP2 and methylated SDC2 was as low as 5 pg per reaction. The optimized cut-off value was methylated SFRP2 analyzed by 3/3 rule and methylated SDC2 analyzed by 2/3 rule. In the training cohort, the sensitivities of stool SpecColon test for detecting AA and early stage CRC (stage 0-II) were 53.8% (95% CI: 26.1%-79.6%) and 89.1% (95% CI: 77.1%-95.5%) with a specificity of 93.5% (95% CI: 87.2%-96.9%), and the AUC for CRC diagnosis was 0.879 (95% CI: 0.830-0.928). Similar performance was achieved by SpecColon test also in the validation cohort, where its sensitivities for detecting AA and early stage CRC (stage 0-II) were 61.5% (95% CI: 32.3-84.9%) and 88.5% (95% CI: 68.5%-97.0%) with a specificity of 89.5% (95% CI: 74.3-96.7%). Conclusion: Combined detections of methylated SFRP2 and methylated SDC2 in stool samples demonstrated high sensitivities and specificity for the detection of AA and early stage CRC. Therefore, this combination has the potential to become an accurate and cost-effective tool for CRC early detection.

DNA methylation markers detected in blood, stool, urine, and tissue in colorectal cancer: a systematic review of paired samples

PURPOSE

Methylated cell-free DNA in liquid biopsies are promising non-invasive biomarkers for colorectal cancer (CRC). Optimal markers would have high sensitivity and specificity for early detection of CRC and could be detected in more than one type of material from the patient. We systematically reviewed the literature on DNA methylation markers of colorectal cancer, detected in more than one type of material, regarding their potential as contributors to a panel for screening and follow-up of CRC.

METHODS

The databases MEDLINE, Web of Science, and Embase were systematically searched. Data extraction and review was performed by two authors independently. Agreement between methylation status in tissue and other materials (blood/stool/urine) was analyzed using the McNemar test and Cohen's kappa.

RESULTS

From the 51 included studies, we identified seven single markers with sensitivity ≥ 75% and specificity ≥ 90% for CRC. We also identified one promising plasma panel and two stool panels. The correspondence of methylation status was evaluated as very good for four markers, but only marginal for most of the other markers investigated (12 of 21).

CONCLUSION

The included studies reported only some of the variables and markers of interest and included few patients. Hence, a meta-analysis was not possible at this point. Larger, prospective studies must be designed to study the discordant detection of markers in tissue and liquid biopsies. When reporting their findings, such studies should use a standardized format.

Diagnostic performance of various liquid biopsy methods in detecting colorectal cancer: A meta-analysis

Liquid biopsy is a promising method in detecting colorectal cancer (CRC). However, previous meta‐analyses only focused on the diagnostic performance of cell‐free DNA (cfDNA). Therefore, we firstly evaluated the overall performance of all liquid biopsy methods. The pooled sensitivities, specificities, diagnostic odds ratios, and area under curve (AUC) of summary receiver operating characteristic curve for all liquid biopsy methods, exosomes, circulating tumor cells (CTCs), and cfDNA were calculated, respectively. A total of 62 articles involving 18 739 individuals were included. Fifty‐one articles were about cfDNA, five articles were about CTCs, and six articles were about exosomes. The overall performance of all liquid biopsy methods had a pooled sensitivity, specificity, and AUC of 0.77 (95% confidence interval [CI] 0.76‐0.78), 0.89 (95% CI 0.88‐0.90), and 0.9004, respectively. The sensitivities were 0.82 (95% CI 0.79‐0.85), 0.76 (95% CI 0.72‐0.80), and 0.76 (95% CI 0.75‐0.77) for CTCs, exosomes, and cfDNA, respectively. The specificities were 0.97 (95% CI95% CI 0.95‐0.99), 0.92 (95% CI 0.89‐0.94), and 0.88 (95% CI 0.87‐0.89) for CTCs, exosomes, and cfDNA, respectively. The AUC were 0.9772, 0.9037, and 0.8963 for CTCs, exosomes, and cfDNA, respectively. The overall performance of all liquid biopsy methods had great diagnostic value in detecting CRC, regardless of subtypes. Among all liquid biopsy methods, CTCs showed the best diagnostic performance.

Application of Multiplex Bisulfite PCR-Ligase Detection Reaction-Real-Time Quantitative PCR Assay in Interrogating Bioinformatically Identified, Blood-Based Methylation Markers for Colorectal Cancer

The analysis of CpG methylation in circulating tumor DNA fragments has emerged as a promising approach for the noninvasive early detection of solid tumors, including colorectal cancer (CRC). The most commonly employed assay involves bisulfite conversion of circulating tumor DNA, followed by targeted PCR, then real-time quantitative PCR (alias methylation-specific PCR). This report demonstrates the ability of a multiplex bisulfite PCR-ligase detection reaction-real-time quantitative PCR assay to detect seven methylated CpG markers (CRC or colon specific), in both simulated (approximately 30 copies of fragmented CRC cell line DNA mixed with approximately 3000 copies of fragmented peripheral blood DNA) and CRC patient-derived cell-free DNAs. This scalable assay is designed for multiplexing and incorporates steps for improved sensitivity and specificity, including the enrichment of methylated CpG fragments, ligase detection reaction, the incorporation of ribose bases in primers, and use of uracil DNA glycosylase. Six of the seven CpG markers (located in promoter regions of PPP1R16B, KCNA3, CLIP4, GDF6, SEPT9, and GSG1L) were identified through integrated analyses of genome-wide methylation data sets for 31 different types of cancer. These markers were mapped to CpG sites at the promoter region of VIM; VIM and SEPT9 are established epigenetic markers of CRC. Additional bioinformatics analyses show that the methylation at these CpG sites negatively correlates with the transcription of their corresponding genes.

Genome-wide DNA methylation profiles of low- and high-grade adenoma reveals potential biomarkers for early detection of colorectal carcinoma

Background

Abnormal DNA methylation is a hallmark of human cancers and may be a promising biomarker for early diagnosis of human cancers. However, the majority of DNA methylation biomarkers that have been identified are based on the hypothesis that early differential methylation regions (DMRs) are maintained throughout carcinogenesis and could be detected at all stages of cancer.

Methods

In this study, we identified potential early biomarkers of colorectal cancer (CRC) development by genome-wide DNA methylation assay (Illumina infinium450, 450 K) of normal (N = 20) and pre-colorectal cancer samples including 18 low-grade adenoma (LGA) and 22 high-grade adenoma (HGA), integrated with GEO and ArrayExpress datasets (N = 833).

Results

We identified 209 and 8692 CpG sites that were significantly hyper-methylated in LGA and HGA, respectively. Pathway analysis identified nervous system-related methylation changes that are significantly associated with early adenoma development. Integration analysis revealed that DNA methylation in the promoter region of ADHFE1 has the most potential for being an early diagnostic biomarker for colorectal adenoma and cancer (sensitivity = 0.96, specificity = 0.95, area under the curve = 0.97).

Conclusions

Overall, we demonstrated that DNA methylation have been shown significant changes in the stage of LGA and HGA in the development of colon cancer. Genome-wide DNA methylation to LGA and HGA provided an important proxy to identify promising early diagnosis biomarkers for colorectal cancer.

Performance Comparison Between Plasma and Stool Methylated SEPT9 Tests for Detecting Colorectal Cancer

Colorectal cancer (CRC) is the most common type of malignancies of the gastrointestinal tract worldwide. Plasma methylated SEPT9 test has been used clinically for CRC screening for several years, but the study about the performance comparison between plasma and stool has rarely been reported. In this study, 124 plasma samples, 100 stool samples, and 60 sets of plasma and paired stool samples were collected and tested by a methylated SEPT9 test in three PCR replicates. The results indicated methylated SEPT9 levels in stool samples were significant higher than those in plasma samples (p < 0.0001). When a plasma sample was called positive if 1 out of 3 PCR replicates was positive and a stool sample was called positive if 3 out of 3 PCR replicates were positive with a mean Cp value of less than 40.0, stool methylated SEPT9 test achieved similar sensitivity (83.3% vs 85.6%) and specificity (92.1% vs 90.1%) to those by plasma methylated SEPT9 test, and the overall concordance rate is 78.3%. However, stool methylated SEPT9 test showed 35.9 and 7.9% improvement in detecting advanced adenomas (AA) and stage I-II CRC in comparison to plasma methylated SEPT9 test. The AUC for plasma methylated SEPT9 and stool methylated SEPT9 in detecting CRC were 0.885 (95% CI: 0.832-0.938) and 0.935 (95% CI: 0.895-0.975), respectively. In conclusion, stool methylated SEPT9 test showed higher sensitivities for detection AA and early stage CRC compared with plasma methylated SEPT9 test, and stool methylated SEPT9 test may be a more suitable tool for early stage CRC screening.

DNA Methylation-Based Testing in Liquid Biopsies as Detection and Prognostic Biomarkers for the Four Major Cancer Types

Lung, breast, colorectal, and prostate cancers are the most incident worldwide. Optimal population-based cancer screening methods remain an unmet need, since cancer detection at early stages increases the prospects of successful and curative treatment, leading to a lower incidence of recurrences. Moreover, the current parameters for cancer patients' stratification have been associated with divergent outcomes. Therefore, new biomarkers that could aid in cancer detection and prognosis, preferably detected by minimally invasive methods are of major importance. Aberrant DNA methylation is an early event in cancer development and may be detected in circulating cell-free DNA (ccfDNA), constituting a valuable cancer biomarker. Furthermore, DNA methylation is a stable alteration that can be easily and rapidly quantified by methylation-specific PCR methods. Thus, the main goal of this review is to provide an overview of the most important studies that report methylation biomarkers for the detection and prognosis of the four major cancers after a critical analysis of the available literature. DNA methylation-based biomarkers show promise for cancer detection and management, with some studies describing a "PanCancer" detection approach for the simultaneous detection of several cancer types. Nonetheless, DNA methylation biomarkers still lack large-scale validation, precluding implementation in clinical practice.

SEPT9_v2, frequently silenced by promoter hypermethylation, exerts anti-tumor functions through inactivation of Wnt/β-catenin signaling pathway via miR92b-3p/FZD10 in nasopharyngeal carcinoma cells

Background

Nasopharyngeal carcinoma tends to present at an advanced stage because the primary anatomic site is located in a less visible area and its clinical symptoms are nonspecific. Prognosis of advanced nasopharyngeal carcinoma cases remains disappointing. SEPT9 is a methylation-based biomarker approved by the US Food and Drug Administration for colorectal cancer screening and diagnosis. Interestingly, downregulation of SEPT9, especially SEPT9_v2, mediated by promoter hypermethylation has been also detected in head and neck squamous cell carcinoma than in head and neck squamous epithelium, while other SEPT9 variants did not. These reasons above indicate a crucial role of SEPT9_v2 in cancer progression. Therefore, we address the methylation status of SEPT9_v2 in nasopharyngeal carcinoma and explore the role of SEPT9_v2 in nasopharyngeal carcinoma proliferation and cancer progression.

Results

SEPT9_v2 expression was found to be downregulated via promoter methylation in nasopharyngeal carcinoma cell lines and tissues. Ectopic expression of SEPT9_v2 induced G0/G1 cell cycle arrest and apoptosis, which exerted an inhibitory effect in cell proliferation and colony formation. Additionally, nasopharyngeal carcinoma cell migration and invasion were shown to be inhibited by SEPT9_v2. Furthermore, our data suggested that SEPT9_v2 inhibits proliferation and migration of nasopharyngeal carcinoma cells through inactivation of the Wnt/β-catenin signaling pathway via miR92b-3p/FZD10.

Conclusions

This study delineates SEPT9_v2, frequently silenced by promoter hypermethylation, exerts anti-tumor functions through inactivation of the Wnt/β-catenin signaling pathway via miR92b-3p/FZD10 in nasopharyngeal carcinoma cells and, hence, SEPT9_v2 may be a promising therapeutic target and biomarker for nasopharyngeal carcinoma.

Utility of the methylated SEPT9 test for the early detection of colorectal cancer: a systematic review and meta-analysis of diagnostic test accuracy

Background

Circulating tumour DNA from colorectal cancer (CRC) is a biomarker for early detection of the disease and therefore potentially useful for screening. One such biomarker is the methylated SEPT9 (mSEPT9) gene, which occurs during CRC tumourigenesis. This systematic review and meta-analysis aims to establish the sensitivity, specificity and accuracy of mSEPT9 tests for the early diagnosis of CRC.

Methods

A systematic search of the relevant literature was conducted using Medline and Embase databases. Data were extracted from the eligible studies and analysed to estimate pooled sensitivity, specificity and diagnostic test accuracy.

Results

Based on 19 studies, the pooled estimates (and 95% CIs) for mSEPT9 to detect CRC were: sensitivity 69% (62-75); specificity 92% (89-95); positive likelihood ratio 9.1 (6.1-13.8); negative likelihood ratio 0.34 (0.27-0.42); diagnostic OR 27 (15-48) and area under the curve 0.89 (0.86-0.91). The test has a positive predictive value of 2.6% and negative predictive value of 99.9% in an average risk population (0.3% CRC prevalence), and 9.5% (positive predictive value) and 99.6% (negative predictive value) in a high-risk population (1.2% CRC prevalence).

Conclusion

The mSEPT9 test has high specificity and moderate sensitivity for CRC and is therefore a potential alternative screening method for those declining faecal immunochemical test for occult blood (FIT) or other screening modalities. However, it is limited by its poor diagnostic performance for precancerous lesions (advanced adenomas and polyps) and its relatively high costs, and little is known about its acceptability to those declining to use the FIT.

Current Update of Laboratory Molecular Diagnostics Advancement in Management of Colorectal Cancer (CRC)

Colorectal cancer (CRC) continues to be one of the most common cancers globally. The incidence has increased in developing countries in the past few decades, this could be partly attributed to aging populations and unhealthy lifestyles. While the treatment of CRC has seen significant improvement since the advent of target-specific therapies and personalized medicine, CRC is oftentimes detected at late or advanced stages, thereby reducing the efficacy of treatment. Hence, screening for early detection is still the key to combat CRC and to increase overall survival (OS). Considering that the field of medical diagnostics is moving towards molecular diagnostics, CRC can now be effectively screened and diagnosed with high accuracy and sensitivity. Depending on the tumor genotype and genetic profile of the individual, personalized treatments including tyrosine kinase inhibitor therapy and immunotherapy can be administered. Notably, there can be no one single treatment that is effective for all CRC patients due to the variation in tumor genetics, which highlights the importance of molecular diagnostics. This review provides insights on therapeutic modalities, molecular biomarkers, advancement of diagnostic technologies, and current challenges in managing CRC.

A Novel Prognostic DNA Methylation Panel for Colorectal Cancer

Colorectal cancer (CRC) is one of the most common cancers and the second leading cause of cancer-related deaths. Discrepancies in clinical outcomes are observed even among patients with same-stage CRC due to molecular heterogeneity. Thus, biomarkers for predicting prognosis in CRC patients are urgently needed. We previously demonstrated that stage II CRC patients with NKX6.1 methylation had poor 5-year overall survival. However, the methylation frequency of NKX6.1 was only 23% in 151 pairs of CRC tissues. Thus, we aimed to develop a more robust prognostic panel for CRC using NKX6.1 in combination with three genes: LIM homeobox transcription factor 1α (LMX1A), sex-determining region Y-box 1 (SOX1), and zinc finger protein 177 (ZNF177). Through quantitative methylation analysis, we found that LMX1A, SOX1, and ZNF177 were hypermethylated in CRC tissues. LMX1A methylation was significantly associated with poor 5-year overall, and disease-free survivals in stage I and II CRC patients. Sensitivity and specificity analyses of the four-gene combination revealed the best sensitivity and optimal specificity. Moreover, patients with the four-gene methylation profile exhibited poorer disease-free survival than those without methylation. A significant effect of the four-gene methylation status on overall survival and disease-free survival was observed in early stage I and II CRC patients (p = 0.0016 and p = 0.0230, respectively). Taken together, these results demonstrate that the combination of the methylation statuses of NKX6.1, LMX1A, SOX1, and ZNF177 creates a novel prognostic panel that could be considered a molecular marker for outcomes in CRC patients.

Diagnostic Value and Clinical Significance of Methylated SEPT9 for Colorectal Cancer: A Meta-Analysis

Background

This meta-analysis aimed to clarify the diagnostic role of plasma methylated SEPT9 (mSEPT9) in colorectal cancer (CRC) and examined its association with CRC.

Material/Methods

A systematic review was conducted prior to July 2018. Summary sensitivity, specificity, and positive and negative likelihood ratio (PLR/NLR) were calculated for the diagnostic value of mSEPT9 for CRC. The areas under the receiver operating curves (AUCs) were used to summarize the overall test performance.

Results

Twenty-two studies with 2271 CRC patients were enrolled. The summary sensitivity, specificity, PLR, NLR, DOR, and AUC of the overall analysis of mSEPT9 were 0.69, 0.92, 8.1, 0.34, 24, and 0.89, respectively. Subgroup and meta-regression analyses demonstrated that the diagnostic value was higher for the Epi proColon 2.0 assay, Asian ethnicity, and mSEPT9 test combined with fecal occult blood test (FOBT) or fecal immunochemical test (FIT) than for other test methods, white ethnicity, and mSEPT9 test alone. The rate of mSEPT9 positivity was higher in advanced CRC cases compared with early-stage CRC cases, and was higher in CRC cases than in adenoma cases. No significant difference in mSEPT9 positivity rate was found between left- and right-sided CRC.

Conclusions

Plasma mSEPT9 has a high diagnostic value for CRC, especially on the newly developed Epi proColon test 2.0 method. The diagnostic sensitivity is superior among Asians compared to whites, and the combination of mSEPT9 and FOBT/FIT has a better performance than mSEPT9 alone. Finally, the expression of mSEPT9 is associated with CRC stage but not with location.

Circulating Biomarkers for Response Prediction of Rectal Cancer to Neoadjuvant Chemoradiotherapy

Rectal cancer response to neoadjuvant Chemoradiotherapy (pCRT) is highly variable. In fact, it has been estimated that only about 21 % of patients show pathologic Complete Response (pCR) after therapy, while in most of the patients a partial or incomplete tumour regression is observed. Consequently, patients with a priori chemoradioresistant tumour should not receive the treatment, which is associated with substantial adverse effects and does not guarantee any clinical benefit. For Locally Advanced Rectal Cancer Patients (LARC), a standardized neoadjuvant treatment protocol is applied, the identification and the usefulness of prognostic or predictive biomarkers can improve the antitumoural treatment strategy, modifying the sequence, dose, and combination of radiotherapy, chemotherapy and surgical resection. For these reasons, a growing number of studies are actually focussed on the discovery and investigation of new predictive biomarkers of response to pCRT. In this review, we have selected the most recent literature (2012-2017) regarding the employment of blood-based biomarkers potentially predicting pCR in LARC patients and we have critically discussed them to highlight their real clinical benefit and the current limitations of the proposed methodological approaches.

Clinical value of preoperative methylated septin 9 in Chinese colorectal cancer patients

BACKGROUND

The methylated septin 9 (mSEPT9) assay was the first blood-based test approved by the United States Food and Drug Administration as a colorectal screening test. However, the diagnostic and prognostic role of preoperative mSEPT9 for colorectal cancer (CRC) in Chinese patients is still unknown.

AIM

To improve the understanding of diagnostic and prognostic factors, serum mSEPT9 was detected in Chinese CRC patients.

METHODS

A retrospective analysis of 354 cases, of which 300 had CRC and 54 were normal, was performed in China. Patients' characteristics, treatments, and laboratory data, including age, the date of surgery, Union for International Cancer Control (UICC) stages, distant metastasis (M), and so on, were collected. Methylation levels of SEPT9 were quantified by quantitative, methylation-specific polymerase chain reaction before surgery. In addition, the effects of mSEPT9 on the occurrence and prognosis of 330 CRC cases from The Cancer Genome Atlas (TCGA) database were evaluated using bioinformatics analyses. Potential prognostic factors for overall survival (OS) and progression-free survival (PFS) were evaluated by Kaplan-Meier univariate analysis.

RESULTS

In Chinese CRC patients, positive mSEPT9 was strongly associated with advanced UICC stages, deeper invasion by the primary tumor, and more distant metastasis. Methylation levels of SEPT9 were stage-dependent and showed a stepwise increase in UICC stages (I-IV), primary tumor categories (T1-T4), regional node categories (N0-N2), and distant metastasis categories (M0-M1). The patients with positive mSEPT9 showed a tendency toward lower PFS. After analyzing TCGA clinical data, the high mSEPT9 group was found to be obviously correlated only with more distant metastasis. The patients with high mSEPT9 levels showed a tendency toward lower OS. Besides, nine meaningful mSEPT9 sites were found to provide guidance for the follow-up studies.

CONCLUSION

MSEPT9 analysis may add valuable information to current tumor staging. Serum mSEPT9 in Chinese CRC patients appears to offer promising novel prognostic markers and might be considered for monitoring CRC recurrence.

Cell-free DNA testing: future applications in gastroenterology and hepatology

The application of next-generation sequencing in clinical practice is increasing as accuracy and interpretation have improved and the cost continues to decline rapidly. Cell-free DNA is a unique source for next-generation sequencing that could change routine clinical practice in gastroenterology and hepatology. Testing of cell-free DNA in blood and fecal samples is an easy, rapid, and noninvasive method to assess for premalignant, malignant, metabolic, infectious, inflammatory, and autoimmune gastrointestinal and liver diseases. In this review, we describe cell-free DNA technologies, current applications of cell-free DNA testing, and proposed cell-free DNA targets for gastrointestinal and hepatic diseases, with a specific focus on malignancy. In addition, we provide commentary on how cell-free DNA can be integrated into clinical practice and help guide diagnosis, prognosis, disease management, and therapeutic response.

Diagnostic Assessment of septin9 DNA Methylation for Colorectal Cancer Using Blood Detection: A Meta-Analysis

This meta-analysis aimed to assess the diagnostic efficiency of blood-based septin 9 (SEPT9) methylation assay for the detection of colorectal cancer (CRC). Studies were searched in the Springer, Wiley, Cochrane Library, PubMed, Ovid, Embase, Web of Science, China BioMedicine, Wanfang and China National Knowledge Infrastructure databases until July 2017. Methodological quality assessment was performed based on the guidelines of the Quality Assessment of Diagnostic Accuracy Studies. According to 1/3 and 2/3 algorithms, the meta-analyses for the diagnostic effect of SEPT9 in CRC were compared with healthy subjects and subjects with polyps, adenoma, and non-CRC, respectively. The random effects model was applied and publication bias was evaluated. The included 29 studies comprised 10,486 subjects (3202 patients with CRC and 7284 controls). In comparison with healthy subjects, the pooled sensitivity with 95% confidence intervals (CIs) of SEPT9 methylation for the diagnosis of CRC was 0.74 (95% CI: 0.61-0.84) in the 1/3 algorithm group, whereas the specificity was 0.96 (95% CI: 0.95-0.97) in the 2/3 algorithm group. Additionally, positive likelihood ratio was less than 10 and negative likelihood ratio more than 0.1 in the 2/3 algorithm group for patients with CRC vs. polyps and adenoma. The P value of Deeks' funnel plot was 0.36, suggesting that there was no publication bias. SEPT9 methylation can be used to diagnose CRC in healthy individuals under the 2/3 algorithm. The determination of SEPT9 methylation does not distinguish well between CRC and polyps or adenoma.

Discovery of methylated circulating DNA biomarkers for comprehensive non-invasive monitoring of treatment response in metastatic colorectal cancer

OBJECTIVE

Mutations in cell-free circulating DNA (cfDNA) have been studied for tracking disease relapse in colorectal cancer (CRC). This approach requires personalised assay design due to the lack of universally mutated genes. In contrast, early methylation alterations are restricted to defined genomic loci allowing comprehensive assay design for population studies. Our objective was to identify cancer-specific methylated biomarkers which could be measured longitudinally in cfDNA (liquid biopsy) to monitor therapeutic outcome in patients with metastatic CRC (mCRC).

DESIGN

Genome-wide methylation microarrays of CRC cell lines (n=149) identified five cancer-specific methylated loci (EYA4, GRIA4, ITGA4, MAP3K14-AS1, MSC). Digital PCR assays were employed to measure methylation of these genes in tumour tissue DNA (n=82) and cfDNA from patients with mCRC (n=182). Plasma longitudinal assessment was performed in a patient subset treated with chemotherapy or targeted therapy.

RESULTS

Methylation in at least one marker was detected in all tumour tissue samples and in 156 mCRC patient cfDNA samples (85.7%). Plasma marker prevalence was 71.4% for EYA4, 68.5% for GRIA4, 69.7% for ITGA4, 69.1% for MAP3K14-AS1% and 65.1% for MSC. Dynamics of methylation markers was not affected by treatment type and correlated with objective tumour response and progression-free survival.

CONCLUSION

This five-gene methylation panel can be used to circumvent the absence of patient-specific mutations for monitoring tumour burden dynamics in liquid biopsy under different therapeutic regimens. This method might be proposed for assessing pharmacodynamics in clinical trials or when conventional imaging has limitations.

Assessing the Impact of Circulating Tumor DNA (ctDNA) in Patients With Colorectal Cancer: Separating Fact From Fiction

Significant advances and increased awareness have been in made in the field of non-invasive liquid biopsies for cancer, spanning several malignancies from gastrointestinal, pulmonary, and other etiologies. Broadly, the genetic source material for liquid biopsies includes circulating tumor cells, cell-free circulating tumor DNA (ctDNA), or cell-free circulating tumor microRNA (mRNA). In this review, we specifically focus on ctDNA and its current role in colorectal cancer. While there are several commercially available assays that detect ctDNA, the utility of these products is still variable and therefore the clinical applications of ctDNA in the management of patients with cancer has yet to be determined. This is reflected by the recent joint review set forth by the American Society of Clinical Oncology (ASCO) and the College of American Pathologists (CAP), clarifying and somewhat tempering the present role of ctDNA in patients with cancer. This review provides additional detail regarding ctDNA in the limited setting of colorectal cancer. The increasing importance and promise of ctDNA remains an area of active research, and further prospective studies may enhance the clinical utility of ctDNA in the future.

Diagnostic Value of Methylated Septin9 for Colorectal Cancer Detection

Background

Methylated Septin9 (mSEPT9) has been suggested as a reliable biomarker in colorectal cancer (CRC) detection. We aimed to determine the diagnostic value of mSEPT9 for CRC detection in Chinese patients. In addition, we compared the diagnostic efficacy of mSEPT9 to traditional screening method [fecal occult blood test (FOBT)] and two biomarkers [carcinoembryonic antigen (CEA) and carbohydrate antigen-199 (Ca-199)].

Methods

Overall 248 subjects including 123 patients with CRC and 125 controls were included. Plasma and fecal samples were collected for CEA, Ca-199, mSEPT9, and FOBT tests. Sensitivity and specificity were calculated to evaluate the diagnostic efficacy of each method; receiver operating characteristic (ROC) curve was plotted for the assessment of diagnostic accuracy, and comparisons among FOBT, mSEPT9, and the combination were assessed through area under the ROC curve (AUC).

Results

mSEPT9 achieved overall sensitivity and specificity of 61.8% [95% confidence interval (CI): 53.0–69.9%] and 89.6% (83.0–93.8%), respectively, with an AUC value of 0.757 (95% CI: 0.701–0.807), superior to FOBT [sensitivity: 61.4% (50.9–70.9%); specificity: 70.3% (59.1–79.5%); AUC: 0.658 (0.578–0.723)], CEA [sensitivity: 35.0% (27.1–43.7%); specificity: 62.6% (53.8–70.7%); AUC: 0.485 (0.411–0.559)], and Ca-199 [sensitivity: 17.9% (12.1–25.6%); specificity: 55.7% (48.9–64.1%); AUC: 0.353 (0.283–0.423)]. The combination of mSEPT9 and FOBT further improved sensitivity and AUC value of 84.1% (75.1–90.3%) and 0.807 (0.752–0.863), respectively, while specificity was declined to 62.2% (50.8–72.4%).

Conclusion

mSEPT9 demonstrated best diagnostic ability in CRC detection compared with FOBT, CEA, and Ca-199. The combination of mSEPT9 and FOBT further improved diagnostic sensitivity especially for early stage disease, which may provide a new approach for future CRC screening, though further investigations are warranted.

Cell-Free Circulating Methylated SEPT9 for Noninvasive Diagnosis and Monitoring of Colorectal Cancer

Identification of early-stage tumor and monitoring therapeutic efficacy and recurrence or metastasis of colorectal cancer (CRC) are urgently warranted for improving the outcome of CRC patients and reducing the disease-related mortality. In this study, we evaluated the diagnostic value of cell-free circulating methylated SEPT9 (mSEPT9) for CRC and beyond CRC and examined the potentiality of mSEPT9 in assessing therapeutic efficacy and monitoring recurrence of CRC. Our results confirmed the favorable diagnostic value of plasma mSEPT9 for CRC, with a sensitivity of 61.22% (95% confidence interval (CI): 51.33%–70.27%) and specificity of 93.7% (95% CI: 91.09%–95.57%) using 2/3 algorithm. The positive rate of mSEPT9 in CRC was correlated with tumor size, histological grade, and general histological type (P < 0.05). Beyond CRC, gastric cancer patients also presented a high positive rate of plasma mSEPT9 (70%). The conversions between preoperative and postoperative plasma mSEPT9 reflected the therapeutic efficacy of curatively intended surgery for CRC patients. The persistent positivity of plasma mSEPT9 after surgery (within 7–14 days) was highly associated with impending recurrences or metastases (within one year), with a sensitivity of 100%. Postoperative mSEPT9 status during follow-up also provided valuable indication for CRC recurrence or metastases, with a good consistency (kappa = 0.818, P = 0.001). Our results verified the reliability of plasma mSEPT9 as a biomarker for noninvasive diagnosis of CRC. More significantly, we revealed its valuable role in appraising CRC therapeutic efficacy and monitoring CRC recurrences or metastases. Further studies with larger sample sizes are needed to verify and elucidate the clinical utility of the promising findings.

Epigenomic biomarkers for prognostication and diagnosis of gastrointestinal cancers

Altered epigenetic regulation is central to many human diseases, including cancer. Over the past two decade, major advances have been made in our understanding of the role of epigenetic alterations in carcinogenesis, particularly for DNA methylation, histone modifications and non-coding RNAs. Aberrant hypermethylation of DNA at CpG islands is a well-established phenomenon that mediates transcriptional silencing of tumor suppressor genes, and it is an early event integral to gastrointestinal cancer development. As such, detection of aberrant DNA methylation is being developed as biomarkers for prognostic and diagnostic purposes in gastrointestinal cancers. Diverse tissue types are suitable for the analyses of methylated DNA, such as tumor tissues, blood, plasma, and stool, and some of these markers are already utilized in the clinical setting. Recent advances in the genome-wide epigenomic approaches are enabling the comprehensive mapping of the cancer methylome, thus providing new avenues for mining novel biomarkers for disease prognosis and diagnosis. Here, we review the current knowledge on DNA methylation biomarkers for the prognostication and non-invasive diagnosis of gastrointestinal cancers and highlight their clinical application.

Potential of quantitative SEPT9 and SHOX2 methylation in plasmatic circulating cell-free DNA as auxiliary staging parameter in colorectal cancer: a prospective observational cohort study

Background

Septin 9 (SEPT9) and short stature homeobox 2 (SHOX2) methylation in circulating cell-free DNA (ccfDNA) are powerful biomarkers for colorectal cancer (CRC) screening, as well as head and neck squamous cell carcinoma staging and monitoring. In the present study, we investigated SEPT9 and SHOX2 ccfDNA methylation as auxiliary pre and post-therapeutic staging parameters in CRC patients.

Methods

ccfDNA methylation was quantified in 184 prospectively enrolled patients prior to and 3–10 days after surgery, and biomarker levels were associated with clinico-pathological parameters.

Results

Pre-therapeutic levels of SHOX2 and SEPT9 ccfDNA methylation were strongly associated with Union for International Cancer Control (UICC) stages, tumour (T), nodal (N), and metastasis (M) categories, and histological grade (all P ≤ 0.001), as well as lymphatic invasion and extracapsular lymph node extension (all P< 0.05). Post-therapeutic SHOX2 and SEPT9 ccfDNA methylation levels correlated with UICC stage (all P  <0.01). SEPT9 ccfDNA methylation further allowed for an accurate pre- and post-therapeutic detection of distant metastases (AUC_{pre-therapeutic} = 0.79 (95%CI 0.69–0.89), AUC_{post-therapeutic} = 0.93 (95% CI 0.79–1.0)).

Conclusions

DNA methylation analysis in plasma is a powerful pre and post-therapeutic diagnostic tool for CRC and may add valuable information to current TNM staging, thereby holding the potential to assist in the development of individually tailored treatment protocols.

Review of Blood-Based Colorectal Cancer Screening: How Far Are Circulating Cell-Free DNA Methylation Markers From Clinical Implementation?

Colorectal cancer (CRC) is a leading cause of cancer related deaths worldwide, and late stages (III-IV) in particular have low 5-year survival rates. Stage shifting by CRC screening programs has proven effective by decreasing morbidity and mortality and in many countries national CRC screening programs have been implemented. Currently, European, Asian, and American authorities recommend screening for CRC using fecal occult blood testing, sigmoidoscopy, or colonoscopy. Because these approaches all have weaknesses (eg, poor compliance, high costs, test invasiveness), much effort has been put into the development of alternative screening approaches, many of which are blood-based. Blood-based strategies especially present the advantages of minimally invasiveness compared to endoscopies and an expectantly higher compliance rate compared to stool-based tests. The last decades have seen many discovery studies identifying promising blood-based biomarkers of CRC; however, common to all of these markers is that their clinical usefulness remains evasive. At present only one blood-based CRC screening marker has been approved in the United States. The aim of this review is to discuss the development of blood-based cell-free DNA methylation marker candidates for CRC screening. On the basis of a methodical literature search, the past, present, and future of cell-free DNA screening markers for CRC are revised and discussed. Resource limitations and technical challenges related to sensitivity and specificity measurements keep many markers at bay. Possible solutions to these problems are offered to enable markers to benefit future screening participants.

Alu methylation serves as a biomarker for non-invasive diagnosis of glioma

Current techniques for diagnosing glioma are invasive and do not accurately predict prognosis. We developed a novel, non-invasive liquid chip assay to diagnose glioma and predict prognosis. Using this method, we determined the methylation state of the Alu element in cell-free DNA extracted from the serum of 109 glioma patients. Controls included 56 patients with benign intracranial tumors and 50 healthy subjects. Matched tumor tissues were processed for 36 patients. The cfDNA from glioma patients showed lower levels of Alu methylation than the controls (P<0.01). Alu methylation was also lower in high-grade than low-grade gliomas (P<0.01), indicating that Alu methylation correlates negatively with disease severity. Moreover, Alu methylation correlated positively with survival (P<0.01). These findings suggest high-throughput liquid chip could serve as a non-invasive diagnostic assay for glioma.

NKX6.1 hypermethylation predicts the outcome of stage II colorectal cancer patients undergoing chemotherapy

Colorectal cancer (CRC) is a common malignancy worldwide. CRC patients in the same stage often present with dramatically different clinical scenarios. Thus, robust prognostic biomarkers are urgently needed to guide therapies and improve treatment outcomes. The NKX6.1 gene has been identified as a hypermethylation marker in cervical cancer, functioning as a metastasis suppressor by regulating epithelial-mesenchymal transition. Here, we investigated whether hypermethylation of NKX6.1 might be a prognostic biomarker for CRC. By analyzing the methylation and expression of NKX6.1 in CRC tissues and CRC cell lines. We quantitatively examined the NKX6.1 methylation levels in 151 pairs of CRC tissues by using methylation-specific polymerase chain reaction analysis and found that NKX6.1 was hypermethylated in 35 of 151 CRC tissues (23%). NKX6.1 gene expression was inversely correlated with the DNA methylation level in CRC cell lines in vitro. Then, we analyzed the association of NKX6.1 methylation with clinical characteristics of these CRC patients. Our data demonstrated that patients with NKX6.1 methylation presented poorer 5-year overall survival (P = 0.0167) and disease-free survival (P = 0.0083) than patients without NKX6.1 methylation after receiving adjuvant chemotherapy. Most importantly, these data revealed that stage II CRC patients with NKX6.1 methylation had poorer 5-year disease-free survival (P = 0.0322) than patients without NKX6.1 methylation after adjuvant chemotherapy. Our results demonstrate that methylation of NKX6.1 is a novel prognostic biomarker in CRC and that it may be used as a predictor of the response to chemotherapy.

Advance in plasma SEPT9 gene methylation assay for colorectal cancer early detection

This review article summarizes the research advances of the plasma-based SEPT9 gene methylation assay for the clinical detection of colorectal cancer and its limitations. Colorectal cancer is a common malignancy with a poor prognosis and a high mortality, for which early detection and diagnosis are particularly crucial for the high-risk groups. Increasing evidence supported that SEPT9 gene methylation is associated with the pathogenesis of colorectal cancer and that detecting the level of methylation of SEPT9 in the peripheral blood can be used for screening of colorectal cancer in susceptible populations. In recent years, the data obtained in clinical studies demonstrated that the SEPT9 gene methylation assay has a good diagnostic performance with regard to both sensitivity and specificity with the advantage of better acceptability, convenience and compliance with serological testing compared with fecal occult blood tests and carcinoembryonic antigen for colorectal cancer (CRC). Furthermore, the combination of multiple methods or markers has become a growing trend for CRC detection and screening. Nevertheless, the clinical availability of the methylated SEPT9 assay is still limited because of the large degree of sample heterogeneity caused by demographic characteristics, pathological features, comorbidities and/or technique selection. Another factor is the cost-effectiveness of colorectal cancer screening strategies that hinders its large-scale application. In addition, improvements in its accuracy in detecting adenomas and premalignant polyps are required.