Biomarker measurement in non-invasively sampled colorectal mucus as a novel approach to colorectal cancer detection: screening and triage implications

Advancing Non-Invasive Colorectal Cancer Screening: Exploring the Potential of Monoclonal Antibody L2A5

Early detection of colorectal cancer (CRC) significantly improves overall prognosis and increases 5-year survival rates up to 90%. Current non-invasive screening methods for CRC, such as the Faecal Immunohistochemical Test (FIT), have some drawbacks, namely, low sensitivity and a high false-positive rate. The Sialyl-Tn (STn) antigen, frequently expressed in pre-malignant lesions and adenocarcinomas, has been shown to be detected by the novel monoclonal antibody L2A5. In this study, we explored the potential of L2A5 as a non-invasive CRC screening method in an attempt to overcome current limitations. The subjects were categorised into four groups based on colonoscopy findings: no lesion (NL), low-grade dysplasia (LGD), high-grade dysplasia (HGD), and colorectal cancer (CRC). Slot blot analysis using the L2A5 antibody was performed on stool samples from 95 colonoscopy patients. Our findings showed a differential STn expression between the different clinical groups, evidencing excellent discrimination between NL and CRC (AUC, 0.8252; 95% CI: 0.6983-0.9521; sensitivity, 70%). Moreover, moderate discrimination between the NL+LGD and HGD+CRC groups was discerned (AUC, 0.7766; 95% CI: 0.6792-0.8740; sensitivity, 58%). These findings support the application of L2A5 as a tool for detecting STn, allowing for the identification of advanced lesions in non-invasive CRC screening.

Biomarkers of inflammation and colorectal cancer risk

Globally, colorectal malignancy ranks among the most prevalent forms of cancer and stands as the third principal cause of cancer-associated mortality. Recent studies indicate that inflammatory processes play a significant role in the initiation and advancement of various malignancies, colorectal cancer included. It explores inflammatory biomarkers, with C-reactive protein (CRP) being a key focus. While CRP's elevation during inflammation is linked to tumorigenesis, studies on its association with CRC risk are inconsistent, showing gender and methodological differences. Interleukin-6 (IL-6), TNF - α, and their receptors also play roles in CRC development, yet research findings vary. Adiponectin and leptin, secreted by adipocytes, have complex associations with CRC, with gender disparities noted. In terms of screening, non-invasive methods like fecal occult blood tests (FOBTs) are widely used, and combining biomarkers with iFOBT shows potential. Multi-omics techniques, including genomics and microbiomics, offer new avenues for CRC diagnosis. Overall, while evidence highlights the significance of inflammatory biomarkers in CRC risk prediction, larger prospective studies are urgently needed to clarify their roles due to existing inconsistencies and methodological limitations.

Machine learning-assisted label-free colorectal cancer diagnosis using plasmonic needle-endoscopy system

Early and accurate detection of colorectal cancer (CRC) is critical for improving patient outcomes. Existing diagnostic techniques are often invasive and carry risks of complications. Herein, we introduce a plasmonic gold nanopolyhedron (AuNH)-coated needle-based surface-enhanced Raman scattering (SERS) sensor, integrated with endoscopy, for direct mucus sampling and label-free detection of CRC. The thin and flexible stainless-steel needle is coated with polymerized dopamine, which serves as an adhesive layer and simultaneously initiates the nucleation of gold nanoparticle (AuNP) seeds on the needle surface. The AuNP seeds are further grown through a surface-directed reduction using Au ions-hydroxylamine hydrochloride solution, resulting in the formation of dense AuNHs. The formation mechanism of AuNHs and the layered structure of the plasmonic needle-based SERS (PNS) sensor are thoroughly analyzed. Furthermore, a strong field enhancement of the PNS sensor is observed, amplified around the edges of the polyhedral shapes and at nanogap sites between AuNHs. The feasibility of the PNS sensor combined with endoscopy system is further investigated using mouse models for direct colonic mucus sampling and verifying noninvasive label-free classification of CRC from normal controls. A logistic regression-based machine learning method is employed and successfully differentiates CRC and normal mice, achieving 100% sensitivity, 93.33% specificity, and 96.67% accuracy. Moreover, Raman profiling of metabolites and their correlations with Raman signals of mucus samples are analyzed using the Pearson correlation coefficient, offering insights for identifying potential cancer biomarkers. The developed PNS-assisted endoscopy technology is expected to advance the early screening and diagnosis approach of CRC in the future.

A simplified and efficient extracellular vesicle-based proteomics strategy for early diagnosis of colorectal cancer

Colorectal cancer (CRC) is a major cause of cancer-related death worldwide and an effective screening strategy for diagnosis of early-stage CRC is highly desired. Although extracellular vesicles (EVs) are expected to become some of the most promising tools for liquid biopsy of early disease diagnosis, the existing EV-based proteomics methods for practical application in clinical samples are limited by technical challenges in high-throughput isolation and detection of EVs. In the current study, we have developed a simplified and efficient EV-based proteomics strategy for early diagnosis of CRC. DSPE-functionalized beads were specifically designed that enabled direct capture of EVs from plasma samples in 10 minutes with good reproducibility and comprehensive proteome coverage. The single-pot, solid-phase-enhanced sample-preparation (SP3) technology was then combined with data-independent acquisition mass spectrometry (DIA-MS) for in-depth analysis and quantification of EV proteomes. From a cohort with 30 individuals including 11 healthy controls, 8 patients with adenomatous polyp and 11 patients with early-stage CRC, our streamlined workflow reproducibly quantified over 800 proteins from their plasma-derived EV samples, from which dysregulated protein signatures for molecular diagnosis of CRC were revealed. We selected a panel of 10 protein markers to train a machine learning (ML) model, which resulted in accurate prediction of polyp and early-stage CRC in an independent and single-blind validation cohort with excellent diagnostic ability of 89.3% accuracy. Our simplified and efficient clinical proteomic strategy will serve as a valuable tool for fast, accurate, and cost-effective diagnosis of CRC that can be easily extended to other disease samples for discovery of unique EV-based biomarkers.

Epigenetic and metabolic reprogramming in inflammatory bowel diseases: diagnostic and prognostic biomarkers in colorectal cancer

BACKGROUND AND AIM

"Inflammatory bowel disease" (IBD) is a chronic, relapsing inflammatory disease of the intestinal tract that typically begins at a young age and might transit to colorectal cancer (CRC). In this manuscript, we discussed the epigenetic and metabolic change to present a extensive view of IBDs transition to CRC. This study discusses the possible biomarkers for evaluating the condition of IBDs patients, especially before the transition to CRC.

RESEARCH APPROACH

We searched "PubMed" and "Google Scholar" using the keywords from 2000 to 2022.

DISCUSSION

In this manuscript, interesting titles associated with IBD and CRC are discussed to present a broad view regarding the epigenetic and metabolic reprogramming and the biomarkers.

CONCLUSION

Epigenetics can be the main reason in IBD transition to CRC, and Hypermethylation of several genes, such as VIM, OSM4, SEPT9, GATA4 and GATA5, NDRG4, BMP3, ITGA4 and plus hypomethylation of LINE1 can be used in IBD and CRC management. Epigenetic, metabolisms and microbiome-derived biomarkers, such as Linoleic acid and 12 hydroxy 8,10-octadecadienoic acid, Serum M2-pyruvate kinase and Six metabolic genes (NAT2, XDH, GPX3, AKR1C4, SPHK and ADCY5) expression are valuable biomarkers for early detection and transition to CRC condition. Some miRs, such as miR-31, miR-139-5p, miR -155, miR-17, miR-223, miR-370-3p, miR-31, miR -106a, miR -135b and miR-320 can be used as biomarkers to estimate IBD transition to CRC condition.

Current Status and Emerging Trends in Colorectal Cancer Screening and Diagnostics

Colorectal cancer (CRC) is a prevalent and potentially fatal disease categorized based on its high incidences and mortality rates, which raised the need for effective diagnostic strategies for the early detection and management of CRC. While there are several conventional cancer diagnostics available, they have certain limitations that hinder their effectiveness. Significant research efforts are currently being dedicated to elucidating novel methodologies that aim at comprehending the intricate molecular mechanism that underlies CRC. Recently, microfluidic diagnostics have emerged as a pivotal solution, offering non-invasive approaches to real-time monitoring of disease progression and treatment response. Microfluidic devices enable the integration of multiple sample preparation steps into a single platform, which speeds up processing and improves sensitivity. Such advancements in diagnostic technologies hold immense promise for revolutionizing the field of CRC diagnosis and enabling efficient detection and monitoring strategies. This article elucidates several of the latest developments in microfluidic technology for CRC diagnostics. In addition to the advancements in microfluidic technology for CRC diagnostics, the integration of artificial intelligence (AI) holds great promise for further enhancing diagnostic capabilities. Advancements in microfluidic systems and AI-driven approaches can revolutionize colorectal cancer diagnostics, offering accurate, efficient, and personalized strategies to improve patient outcomes and transform cancer management.

Bacterial biomarkers: new aspects of colorectal tumors diagnosis: reality or fantasy

As one of the most common cancers, colorectal cancer (CRC) is considered as a significant leading cause of cancer-related deaths worldwide. Gut microbiota is part of a complex microbial-based ecosystem in the human body so that changes in the microbiota could lead to a variety of diseases. A growing number of studies have shown that bacteria are both individually and collectively involved in the progression of CRC. The present review study provided a summary of some of the available data on the advantages and limitations of current CRC screening methods as well as gut biomarkers including genetic, epigenetic, and protein markers. Moreover, a summary of the applications and limitations in the detection of gut microbiota markers as well as their role in early diagnosis and timely treatment response in CRC patients was provided.

Colon mucus in colorectal neoplasia and beyond

Little was known about mammalian colon mucus (CM) until the beginning of the 21st century. Since that time considerable progress has been made in basic research addressing CM structure and functions. Human CM is formed by two distinct layers composed of gel-forming glycosylated mucins that are permanently secreted by goblet cells of the colonic epithelium. The inner layer is dense and impenetrable for bacteria, whereas the loose outer layer provides a habitat for abundant commensal microbiota. Mucus barrier integrity is essential for preventing bacterial contact with the mucosal epithelium and maintaining homeostasis in the gut, but it can be impaired by a variety of factors, including CM-damaging switch of commensal bacteria to mucin glycan consumption due to dietary fiber deficiency. It is proven that impairments in CM structure and function can lead to colonic barrier deterioration that opens direct bacterial access to the epithelium. Bacteria-induced damage dysregulates epithelial proliferation and causes mucosal inflammatory responses that may expand to the loosened CM and eventually result in severe disorders, including colitis and neoplastic growth. Recently described formation of bacterial biofilms within the inner CM layer was shown to be associated with both inflammation and cancer. Although obvious gaps in our knowledge of human CM remain, its importance for the pathogenesis of major colorectal diseases, comprising inflammatory bowel disease and colorectal cancer, is already recognized. Continuing progress in CM exploration is likely to result in the development of a range of new useful clinical applications addressing colorectal disease diagnosis, prevention and therapy.

Emerging role of colorectal mucus in gastroenterology diagnostics

Colonoscopy is currently the gold standard for diagnosis of inflammatory bowel disease (IBD) and colorectal cancer (CRC). This has the obvious drawback of being invasive as well as carrying a small risk. The most widely used non-invasive approaches include the use of faecal calprotectin in the case of IBD and fecal immunochemical test in the case of CRC. However, the necessity of stool collection limits their acceptability for some patients. Over the recent years, there has been emerging data looking at the role of non-invasively obtained colorectal mucus as a screening and diagnostic tool in IBD and CRC. It has been shown that the mucus rich material obtained by self-sampling of anal surface following defecation, can be used to measure various biomarkers that can aid in diagnosis of these conditions.

Comparison of faecal protein biomarkers' diagnostic accuracy for colorectal advanced neoplasms: a systematic review and meta-analysis

Early diagnosis of colorectal advanced neoplasms (ANs), including colorectal cancer (CRC) and advanced adenoma (AA), has a positive effect on the survival rate. As a first attempt, the aim of this meta-analysis was to compare the diagnostic accuracy of faecal protein biomarkers for the detection of colorectal neoplasms with consideration of a wide range of covariates. A systematic literature search was performed up to Jun 10, 2021 on Web of Sciences, Scopus and PubMed. The diagnostic accuracies were calculated using the bivariate/hierarchical random effect model. Biomarkers were determined to be clinically applicable (CA) if they had areas under the curve > 0.70 and positive and negative likelihood ratios > 2 and < 0.5, respectively. A total of 47,059 test results were extracted from 16 immunochemical faecal occult blood test (iFOBT), 26 pyruvate kinase-M2 (PK-M2) and 23 faecal calprotectin (FC) studies. Only iFOBT, PK-M2 and FC for CRC plus iFOBT and PK-M2 for AN were CA. iFOBT had significantly superior accuracy (P = 0.02 versus PK-M2 and P < 0.01 versus FC for CRC; P < 0.01 versus PK-M2 for AN). Regarding covariates, the lateral flow method of PK-M2 measurement increased its accuracy for CRC detection compared to the enzyme-linked immunosorbent assay (P < 0.01). iFOBT is recommended as the most accurate faecal biomarker for CRC and AN diagnosis.

Biomarkers to Detect Early-Stage Colorectal Cancer

Colorectal cancer is a leading cause of mortality worldwide. The high incidence and the acceleration of incidence in younger people reinforces the need for better techniques of early detection. The use of noninvasive biomarkers has potential to more accurately inform how patients are prioritised for clinical investigation, which, in turn, may ultimately translate into improved survival for those subsequently found to have curable-stage CRC. This review surveys a wide range of CRC biomarkers that may (alone or in combination) identify symptomatic patients presenting in primary care who should be progressed for clinical investigation.