Evaluation of a 5-Marker Blood Test for Colorectal Cancer Early Detection in a Colorectal Cancer Screening Setting

Enhancing the diagnostic accuracy of colorectal cancer through the integration of serum tumor markers and hematological indicators with machine learning algorithms

BACKGROUND

Colorectal cancer has a high incidence and mortality rate due to a low rate of early diagnosis. Therefore, efficient diagnostic methods are urgently needed.

PURPOSE

This study assesses the diagnostic effectiveness of Carbohydrate Antigen 19-9 (CA19-9), Carcinoembryonic Antigen (CEA), Alpha-fetoprotein (AFP), and Cancer Antigen 125 (CA125) serum tumor markers for colorectal cancer (CRC) and investigates a machine learning-based diagnostic model incorporating these markers with blood biochemical indices for improved CRC detection.

METHOD

Between January 2019 and December 2021, data from 800 CRC patients and 697 controls were collected; 52 patients and 63 controls attending the same hospital in 2022 were collected as an external validation set. Markers' effectiveness was analyzed individually and collectively, using metrics like ROC curve AUC and F1 score. Variables chosen through backward regression, including demographics and blood tests, were tested on six machine learning models using these metrics.

RESULT

In the case group, the levels of CEA, CA199, and CA125 were found to be higher than those in the control group. Combining these with a fourth serum marker significantly improved predictive efficacy over using any single marker alone, achieving an Area Under the Curve (AUC) value of 0.801. Using stepwise regression (backward), 17 variables were meticulously selected for evaluation in six machine learning models. Among these models, the Gradient Boosting Machine (GBM) emerged as the top performer in the training set, test set, and external validation set, boasting an AUC value of over 0.9, indicating its superior predictive power.

CONCLUSION

Machine learning models integrating tumor markers and blood indices offer superior CRC diagnostic accuracy, potentially enhancing clinical practice.

Significance of SDC2 and NDRG4 methylation in stool for colorectal cancer diagnosis

BACKGROUND

Recent studies have identified methylated SDC2 and NDRG4 in colorectal cancer (CRC), however, the diagnostic value of the combined two genes remains undefined. This study aims to investigate the methylation of SDC2 and NDRG4 in stool samples and their application in diagnosis of CRC.

METHODS

Five groups were enrolled in our study which consisted of CRC (n = 138), advanced adenomas (n = 27), polyp (n = 35), intestinal disease control (n = 150), and healthy individuals (n = 28). Methylation status of SDC2 and NDRG4 in fecal samples were tested with appropriate commercial kits. Primary data were collected and statistical analyses were performed.

RESULTS

The positive rates of both SDC2 and NDRG4 methylation in stool samples of CRC group were significantly higher (P < 0.001) than those of either group of advanced adenomas, or polyp, or intestinal disease or the healthy control. It was suggested that both methylated SDC2,NDRG4, SDC2/NDRG4 and age were independent risk factors for CRC. The sensitivity of SDC2 and NDRG4 for CRC diagnosis were 73.9 % and 63.0 %, respectively, while SDC2 combined with NDRG4 had a higher sensitivity of 85.5 %. The specificity of SDC2, NDRG4 and SDC2 combined with NDRG4 achieved 91.6 %, 88.3 % and 84.6 %, respectively. The AUC for methylated SDC2 and NDRG4 were 0.828 (95 % CI: 0.780-0.876) and 0.757 (95 % CI: 0.703-0.811), respectively. In contrast, SDC2 combined with NDRG4 improved the AUC to 0.850 (95 % CI: 0.807-0.893).

CONCLUSIONS

This research confirmed the significance of detection of SDC2 and NDRG4 methylation by using noninvasive samples of stool. More importantly, attributing to their high level and frequency of methylation in stool, SDC2 and NDRG4 could be promising biomarkers for stool-based method for screening and early diagnosis of CRC, especially when combined.

Radiomics-based T-staging of hollow organ cancers

Cancer growing in hollow organs has become a serious threat to human health. The accurate T-staging of hollow organ cancers is a major concern in the clinic. With the rapid development of medical imaging technologies, radiomics has become a reliable tool of T-staging. Due to similar growth characteristics of hollow organ cancers, radiomics studies of these cancers can be used as a common reference. In radiomics, feature-based and deep learning-based methods are two critical research focuses. Therefore, we review feature-based and deep learning-based T-staging methods in this paper. In conclusion, existing radiomics studies may underestimate the hollow organ wall during segmentation and the depth of invasion in staging. It is expected that this survey could provide promising directions for following research in this realm.

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.

Optimizing Screening for Colorectal Cancer: An Algorithm Combining Fecal Immunochemical Test, Blood-Based Cancer-Associated Proteins and Demographics to Reduce Colonoscopy Burden

BACKGROUND

Fecal Immunochemical Test (FIT) is widely used in population-based screening for colorectal cancer (CRC). This had led to major challenges regarding colonoscopy capacity. Methods to maintain high sensitivity without compromising the colonoscopy capacity are needed. This study investigates an algorithm that combines FIT result, blood-based biomarkers associated with CRC, and individual demographics, to triage subjects sent for colonoscopy among a FIT positive (FIT⁺) screening population and thereby reduce the colonoscopy burden.

MATERIALS AND METHODS

From the Danish National Colorectal Cancer Screening Program, 4048 FIT⁺ (≥100 ng/mL Hemoglobin) subjects were included and analyzed for a panel of 9 cancer-associated biomarkers using the ARCHITECT i2000. Two algorithms were developed: 1) a predefined algorithm based on clinically available biomarkers: FIT, age, CEA, hsCRP and Ferritin; and 2) an exploratory algorithm adding additional biomarkers: TIMP-1, Pepsinogen-2, HE4, CyFra21-1, Galectin-3, B2M and sex to the predefined algorithm. The diagnostic performances for discriminating subjects with or without CRC in the 2 models were benchmarked against the FIT alone using logistic regression modeling.

RESULTS

The discrimination of CRC showed an area under the curve (AUC) of 73.7 (70.5-76.9) for the predefined model, 75.3 (72.1-78.4) for the exploratory model, and 68.9 (65.5-72.2) for FIT alone. Both models performed significantly better (P < .001) than the FIT model. The models were benchmarked vs. FIT at cutoffs of 100, 200, 300, 400, and 500 ng/mL Hemoglobin using corresponding numbers of true positives and false positives. All performance metrics were improved at all cutoffs.

CONCLUSION

A screening algorithm including a combination of FIT result, blood-based biomarkers and demographics outperforms FIT in discriminating subjects with or without CRC in a screening population with FIT results above 100 ng/mL Hemoglobin.

Combination of automated sample preparation and micro-flow LC-MS for high-throughput plasma proteomics

BACKGROUND

Non-invasive detection of blood-based markers is a critical clinical need. Plasma has become the main sample type for clinical proteomics research because it is easy to obtain and contains measurable protein biomarkers that can reveal disease-related physiological and pathological changes. Many efforts have been made to improve the depth of its identification, while there is an increasing need to improve the throughput and reproducibility of plasma proteomics analysis in order to adapt to the clinical large-scale sample analysis.

METHODS

We have developed and optimized a robust plasma analysis workflow that combines an automated sample preparation platform with a micro-flow LC-MS-based detection method. The stability and reproducibility of the workflow were systematically evaluated and the workflow was applied to a proof-of-concept plasma proteome study of 30 colon cancer patients from three age groups.

RESULTS

This workflow can analyze dozens of samples simultaneously with high reproducibility. Without protein depletion and prefractionation, more than 300 protein groups can be identified in a single analysis with micro-flow LC-MS system on a Orbitrap Exploris 240 mass spectrometer, including quantification of 35 FDA approved disease markers. The quantitative precision of the entire workflow was acceptable with median CV of 9%. The preliminary proteomic analysis of colon cancer plasma from different age groups could be well separated with identification of potential colon cancer-related biomarkers.

CONCLUSIONS

This workflow is suitable for the analysis of large-scale clinical plasma samples with its simple and time-saving operation, and the results demonstrate the feasibility of discovering significantly changed plasma proteins and distinguishing different patient groups.

CTPS1 inhibition suppresses proliferation and migration in colorectal cancer cells

Colorectal cancer (CRC) is now the third most prevalent tumor and one of the deadliest cancers worldwide, with an increasing prevalence every year. Therefore, we urgently need to understand the mechanisms regulating the progression of colorectal cancer and find potential diagnostic biomarkers. In this study, we performed an analysis using the TCGA and GEO databases to find a molecular biomarker for the diagnosis of CRC, namely CTPS1. The results of this analysis revealed that CTPS1 could promote tumor proliferation and metastasis. Furthermore, bioinformatics analysis revealed that CTPS1 promoted CRC progression through cell cycle and p53 pathways. Further investigation demonstrated that CTPS1 might be involved in the regulation of CCNB1, RRM2, GTSE1, CDK2 and CHEK2 genes. Moreover, PCR confirmed that CTPS1 regulated GTSE1 and CDK2 molecules. Then, western blot was used to verify that CTPS1 promoted the expression of GTSE1 and CDK2 by inhibiting the expression of p53. In summary, we identified an important diagnostic biomarker for CRC, namely CTPS1, and its importance was validated at the cellular level. These results suggest that CTPS1 could serve as a candidate biomarker for CRC and CTPS1 inhibitors may be a potential treatment for CRC.

FJX1 as a candidate diagnostic and prognostic serum biomarker for colorectal cancer

PURPOSE

Colorectal cancer (CRC) is one of the most common cancer worldwide. It is essential to identify non-invasive diagnostic and prognostic biomarkers of CRC. The aim of the present study was to screen candidate biomarkers in diagnosis and prognosis of CRC based on a novel strategy.

MATERIALS AND METHODS

The expression level of gene higher in cancer than in adjacent non-cancer tissue was defined as "positive", and the top 10% genes with "positive rate" were filtered out as candidate diagnostic biomarkers in four Gene Expression Omnibus (GEO) datasets. Then, the prognostic value of candidate biomarkers was estimated Cox regression analysis. Moreover, the concentration of biomarker in serum was detected in CRC patients.

RESULTS

Eighteen candidate biomarkers were identified with efficient diagnostic value in CRC. As a prognostic biomarker, FJX1 (four-jointed box kinase 1) showed a good performance in predicting overall survivals in CRC patients. In serum levels, FJX1 showed high sensitivity and specificity in distinguishing CRC patients from controls, and the concentration of serum FJX1 was associated with distant metastasis in CRC. In addition, serum FJX1 was significantly decreased after surgery in CRC patients. Compared with traditional CRC biomarkers CEA and CA 19-9, FJX1 still showed good efficiency in diagnosis and prognosis. Moreover, inhibition of FJX1 expression by siRNA or neutralization of secreted FJX1 by antibody could suppress cell proliferation and migration in vitro.

CONCLUSION

Our findings provided a novel strategy to identify diagnostic biomarkers based on public datasets, and suggested that FJX1 was a candidate diagnostic and prognostic biomarker in CRC patients.

Screening of serum oxysterol biomarkers for colon cancer by liquid chromatography-tandem mass spectrometry

结肠癌(CC)是全球常见恶性肿瘤之一,发病率呈逐年上升趋势,目前没有有效的标志物用于疾病早期诊断和干预跟踪。胆固醇及其氧化衍生物氧固醇在众多恶性肿瘤发生发展中发挥关键作用。该研究采用液相色谱-串联质谱(LC-MS/MS)技术,对CC临床血清样本中胆固醇及相关10种氧固醇代谢物进行了定性定量分析,并采用偏最小二乘判别分析(PLS-DA)和正交偏最小二乘判别分析(OPLS-DA)进行多元统计分析,发现上述目标代谢物能够较好地区分CC组与健康对照组。为防止数据过拟合,该研究在PLS-DA模型各代谢物变量投影重要性(VIP)基础上,结合最优组分数及K-均值聚类结果,筛选得到3种代谢标志物。通过受试者操作特征曲线(ROC)的曲线下面积(AUC)分析,发现筛选得到的3种潜在标志物联合预测CC达到0.998,说明模型性能优良。GO(基因本体论)富集分析显示3种潜在标志物主要分布在内质网和包被囊泡上,参与胆固醇代谢、运输、低密度脂蛋白重塑等生物进程,发挥胆固醇运输活性和低密度脂蛋白颗粒受体结合的分子功能。KEGG(京都基因与基因组百科全书)通路分析显示3种潜在标志物富集于类固醇生物合成、PPAR(过氧化物酶体增殖物激活受体)信号通路及ABC(ATP结合盒)转运等通路上。该研究为寻找CC标志物及进一步阐明胆固醇及氧固醇在CC发病过程中的作用奠定了一定的基础。

A model of multiple tumor marker for lymph node metastasis assessment in colorectal cancer: a retrospective study

Background

Assessment of colorectal cancer (CRC) lymph node metastasis (LNM) is critical to the decision of surgery, prognosis, and therapy strategy. In this study, we aimed to develop and validate a multiple tumor marker nomogram for predicting LNM in CRC patients.

Methods

A total of 674 patients who met the inclusion criteria were collected and randomly divided into primary cohort and internal test cohort at a ratio of 7:3. An external test cohort enrolled 178 CRC patients from the West China Hospital. Clinicopathologic variables were obtained from electronic medical records. The least absolute shrinkage and selection operator (LASSO) and interquartile range analysis were carried out for variable dimensionality reduction and feature selection. Multivariate logistic regression analysis was conducted to develop predictive models of LNM. The performance of the established models was evaluated by the receiver operating characteristic (ROC) curve, calibration belt, and clinical usefulness.

Results

Based on minimum criteria, 18 potential features were reduced to six predictors by LASSO and interquartile range in the primary cohort. The model demonstrated good discrimination and ROC curve (AUC = 0.721 in the internal test cohort, AUC = 0.758 in the external test cohort) in LNM assessment. Good calibration was shown for the probability of CRC LNM in the internal and external test cohorts. Decision curve analysis illustrated that multi-tumor markers nomogram was clinically useful.

Conclusions

The study proposed a reliable nomogram that could be efficiently and conveniently utilized to facilitate the assessment of individually-tailored LNM in patients with CRC, complementing imaging and biopsy tests.

Correlation of Repeat Measurements of 27 Candidate Protein Markers for Colorectal Cancer Screening Taken Three Years and Multiple Freeze-Thaw Cycles Apart

In recent years the blood proteome has been increasingly researched for biomarkers for early detection of colorectal cancer (CRC). Blood samples from screening studies are often subject to preanalytical variability and repeated freeze−thaw cycles. We aimed to assess the correlation of repeat measurements of 27 candidate protein markers for CRC screening taken three years and multiple freeze−thaw cycles apart. The concentrations of 27 protein markers were measured in plasma samples of 39 newly detected CRC cases from a cohort of 9245 participants of screening colonoscopies. The proteins were measured using proximity extension assays (PEA) carried out on the same set of samples twice, three years apart, with an average of three freeze−thaw cycles in between the two measurements. Pearson’s product moment correlation coefficients were calculated. Correlation coefficients ranged from +0.43 to +0.97, with a median of 0.67 and an interquartile range of +0.58 to +0.84, with all p-values of correlation being <0.01 (<0.0005 for 22 proteins, <0.001 for 4 proteins). Repeat measurements of the 27 protein biomarkers for CRC screening performed three years later, and on average three freeze−thaw cycles apart, showed moderate to high levels of correlation. Apart from the effects of freeze−thaw cycles, slightly different preprocessing performed on the data may have contributed to recorded differences between measurements.

Methylation of SDC2/TFPI2 and Its Diagnostic Value in Colorectal Tumorous Lesions

Background:SDC2 methylation is a feasible biomarker for colorectal cancer detection. Its specificity for colorectal cancer is higher than 90%, but the sensitivity is normally lower than 90%. This study aims to improve the sensitivity of SDC2 detection through finding a high positive target from the false-negative samples of SDC2 detection based on analysis of the bowel subsite difference in methylation.

Methods: Hypermethylated TFPI2 was identified in SDC2 hypomethylated colorectal cancer samples retrieved from TCGA database with the methylation level lower than 0.2. The methylation-specific PCR assay was developed and then evaluated using tissue samples (184 cancer and 54 healthy control samples) and stool samples (289 cancer, 190 adenoma, and 217 healthy control samples).

Results:TFPI2 was hypermethylated in most SDC2 hypomethylated colorectal cancer samples. When the SDC2/TFPI2-combined PCR assay was performed in stool specimens, the AUC value of cancer vs. control was 0.98, with the specificity of 96.40% and sensitivity of 96.60%, and the AUC value of adenoma vs. control was 0.87, with the specificity of 95.70% and the sensitivity of 80.00%. The improvement in sensitivity was the most momentous in the left colon. As the detection index, the Ct value was better in improving the sensitivity of detection than the methylation level based on the 2^−ΔΔCt value.

Conclusion:TFPI2 can improve the sensitivity of SDC2 methylation–specific detection of colorectal tumorous lesions while maintaining high specificity, in particular reducing the missed detection of left colon cancer and adenoma.

Dysbiosis of human gut microbiome in young-onset colorectal cancer

The incidence of sporadic young-onset colorectal cancer (yCRC) is increasing. A significant knowledge gap exists in the gut microbiota and its diagnostic value for yCRC patients. Through 16S rRNA gene sequencing, 728 samples are collected to identify microbial markers, and an independent cohort of 310 samples is used to validate the results. Furthermore, species-level and functional analysis are performed by metagenome sequencing using 200 samples. Gut microbial diversity is increased in yCRC. Flavonifractor plautii is an important bacterial species in yCRC, while genus Streptococcus contains the key phylotype in the old-onset colorectal cancer. Functional analysis reveals that yCRC has unique characteristics of bacterial metabolism characterized by the dominance of DNA binding and RNA-dependent DNA biosynthetic process. The random forest classifier model achieves a powerful classification potential. This study highlights the potential of the gut microbiota biomarkers as a promising non-invasive tool for the accurate detection and distinction of individuals with yCRC.

Machine Learning Models Cannot Replace Screening Colonoscopy for the Prediction of Advanced Colorectal Adenoma

Screening for colorectal cancer (CRC) continues to rely on colonoscopy and/or fecal occult blood testing since other (non-invasive) risk-stratification systems have not yet been implemented into European guidelines. In this study, we evaluate the potential of machine learning (ML) methods to predict advanced adenomas (AAs) in 5862 individuals participating in a screening program for colorectal cancer. Adenomas were diagnosed histologically with an AA being ≥ 1 cm in size or with high-grade dysplasia/villous features being present. Logistic regression (LR) and extreme gradient boosting (XGBoost) algorithms were evaluated for AA prediction. The mean age was 58.7 ± 9.7 years with 2811 males (48.0%), 1404 (24.0%) of whom suffered from obesity (BMI ≥ 30 kg/m²), 871 (14.9%) from diabetes, and 2095 (39.1%) from metabolic syndrome. An adenoma was detected in 1884 (32.1%), as well as AAs in 437 (7.5%). Modelling 36 laboratory parameters, eight clinical parameters, and data on eight food types/dietary patterns, moderate accuracy in predicting AAs with XGBoost and LR (AUC-ROC of 0.65–0.68) could be achieved. Limiting variables to established risk factors for AAs did not significantly improve performance. Moreover, subgroup analyses in subjects without genetic predispositions, in individuals aged 45–80 years, or in gender-specific analyses showed similar results. In conclusion, ML based on point-prevalence laboratory and clinical information does not accurately predict AAs.

Risk-Predictive and Diagnostic Biomarkers for Colorectal Cancer; a Systematic Review of Studies Using Pre-Diagnostic Blood Samples Collected in Prospective Cohorts and Screening Settings

This systematic review summarizes the evidence for blood-based colorectal cancer biomarkers from studies conducted in pre-diagnostic, asymptomatic settings. Of 1372 studies initially identified, the final selection included 30 studies from prospective cohorts and 23 studies from general screening settings. Overall, the investigations had high quality but considerable variability in data analysis and presentation of results, and few biomarkers demonstrated a clinically relevant discriminatory ability. One of the most promising biomarkers was the anti-p53 antibody, with consistent findings in one screening cohort and in the 3-4 years prior to diagnosis in two prospective cohort studies. Proteins were the most common type of biomarker assessed, particularly carcinoembryonic antigen (CEA) and C-reactive protein (CRP), with modest results. Other potentially promising biomarkers included proteins, such as AREG, MIC-1/GDF15, LRG1 and FGF-21, metabolites and/or metabolite profiles, non-coding RNAs and DNA methylation, as well as re-purposed routine lab tests, such as ferritin and the triglyceride-glucose index. Biomarker panels generally achieved higher discriminatory performance than single markers. In conclusion, this systematic review highlighted anti-p53 antibodies as a promising blood-based biomarker for use in colorectal cancer screening panels, together with other specific proteins. It also underscores the need for validation of promising biomarkers in independent pre-diagnostic settings.

Osteopontin as a Regulator of Colorectal Cancer Progression and Its Clinical Applications

Simple Summary

The mortality of colorectal cancer is principally related to metastatic disease at the time of diagnosis or to the growth of initially undetectable micro-metastasis. Current therapeutic strategies are efficient in patients with locally advanced cancer, but are rarely able to cure patients with metastatic disease. Therapeutic failure is mainly associated with drug resistance and an aggressive phenotype. The identification of new biomarkers for micro-metastasis and tumor progression remains an unmet clinical need that should allow for improved patient stratification for optimal treatment and may lead to the identification of novel therapeutic targets. Osteopontin (OPN), a multifunctional protein, has emerged as a potentially valuable biomarker in several cancer types. This review principally describes the molecular mechanisms of OPN that are associated with colorectal cancer (CRC) progression and metastasis, as well as the use of OPN as a clinical biomarker. This review identifies a role for OPN as a biomarker ready for extended clinical application and discusses its use as a therapeutic target.

Abstract

A high expression of the phosphoprotein osteopontin (OPN) has been associated with cancer progression in several tumor types, including breast cancer, hepatocarcinoma, ovarian cancer, and colorectal cancer (CRC). Interestingly, OPN is overexpressed in CRC and is associated with a poor prognosis linked to invasion and metastasis. Here, we review the regulation and functions of OPN with an emphasis on CRC. We examine how epigenetic and genetic regulators interact with the key signaling pathways involved in this disease. Then, we describe the role of OPN in cancer progression, including proliferation, survival, migration, invasion, and angiogenesis. Furthermore, we outline the interest of using OPN as a clinical biomarker, and discuss if and how osteopontin can be implemented as a routine assay in clinical laboratories for monitoring CRC patients. Finally, we discuss the use of OPN an attractive, but challenging, therapeutic target.

Advances in Early Detection of Colorectal Cancer: A Focus on Non-invasive Biomarkers

BACKGROUND

Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide. Currently, colonoscopy remains the gold standard diagnostic test for CRC detection. Nonetheless, this technique is invasive and expensive. Remarkable ongoing strategies are focusing on the development of affordable methods to diagnose CRC at earlier stages. The introduction of suitable noninvasive, sensitive and specified diagnostic tests for early CRC detection by employing biomarker analysis seems to be a fundamental need to reduce the numbers of unnecessary colonoscopies. In this review, we provide an overview of single- and multi-panel biomarkers (Genomic markers, transcriptome markers, proteomic markers, inflammatory markers, and microbiome markers) encompassing noninvasive tests in blood and stool for early CRC detection.

METHODS

A bibliographic search using PubMed/Medline, Web of Science, and EBSCOhost databases was performed to find relevant published studies over the last 6 years. Forty-three pertinent studies were included in this review.

RESULTS

The primary outcome highlights the sensitivity and specificity of single diagnostic biomarkers studied in blood or stool. The secondary outcome reveals the sensitivity and specificity of the biomarkers panel (combinations) in blood or stool. While some markers show better performance, others are not suitable for screening purposes.

CONCLUSION

There is a need to adjust experimental and analytical tests that can interfere with a robust result to replace or supplement those markers that are currently in use. Nevertheless, robust verification and validation with large clinical cohorts are needed for successful noninvasive tests that can fulfill the role of colonoscopy.

Impact of Inadequate Bowel Cleansing on Colonoscopic Findings in Routine Screening Practice

INTRODUCTION

Colonoscopy is an imperfect gold standard for detecting colorectal neoplasms because some proportion of adenomas may be missed, mainly small lesions. This proportion is expected to be higher in case of inadequate bowel cleansing, which is frequently seen in routine practice. We estimated the proportions of neoplasms that are in principle detectable by colonoscopy but might be missed in case of incomplete bowel preparation.

METHODS

For 8,193 participants of screening colonoscopy in South-Western Germany, recruited between 2005 and 2016, the prevalence and numbers of different findings were extracted from colonoscopy reports and compared according to the reported bowel preparation quality.

RESULTS

Bowel preparation quality was reported as good, poor, or was unspecified in 30.3%, 11.1%, and 58.6% of colonoscopy records. Reported prevalences of nonadvanced adenomas (NAAs) were similar among participants with poor and unspecified bowel preparation quality but substantially lower than among participants with good bowel preparation (adjusted prevalence rate ratio [RR] 0.86, 95% confidence interval [CI]: 0.77-0.96). The differences were observed for proximal but not for distal NAAs (RRs 0.82, 95% CI: 0.71-0.95 and 0.95, 95% CI: 0.82-1.10).

DISCUSSION

Our study suggests that a significant proportion of NAAs located in the proximal colon might be missed during colonoscopy if bowel cleansing is not adequate. Major efforts should be made to further facilitate and enhance high-quality bowel preparation in routine screening practice.

Sensitive detection of colorectal cancer in peripheral blood by a novel methylation assay

BACKGROUND

Colorectal cancer (CRC) is a leading cause of cancer-related deaths worldwide. Early detection of CRC can significantly reduce its mortality rate. Current method of CRC diagnosis relies on the invasive endoscopy. Non-invasive assays including fecal occult blood testing (FOBT) and fecal immunological test (FIT) are compromised by low sensitivity and specificity, especially at early stages. Thus, a non-invasive and accurate approach for CRC screening would be highly desirable.

RESULTS

A new qPCR-based assay combining the simultaneous detection of the DNA methylation status of ten candidate genes was used to examine plasma samples from 56 normal controls, 6 hyperplastic polys, 9 non-advanced adenomas (NAAs), 22 advanced adenomas (AAs) and 175 CRC patients, using 10 ng of cfDNA. We further built a logistic regression model for CRC diagnosis. We tested ten candidate methylation markers including twist1, vav3-as1, fbn1, c9orf50, sfmbt2, kcnq5, fam72c, itga4, kcnj12 and znf132. All markers showed moderate diagnostic performance with AUCs ranging from 0.726 to 0.815. Moreover, a 4-marker model, comprised of two previously reported markers (c9orf50 and twist1) and two novel ones (kcnj12 and znf132), demonstrated high performance for detecting colorectal cancer in an independent validation set (N = 69) with an overall AUC of 0.911 [95% confidence interval (CI) 0.834-0.988], sensitivity of 0.800 [95% CI 0.667-0.933] and specificity of 0.971 [95% CI 0.914-1.000]. The stage-stratified sensitivity of the model was 0.455 [95% CI 0.227-0.682], 0.667 [95% CI 0.289-1.000], 0.800 [95% CI 0.449-1.000], 0.800 [95% CI 0.449-1.000] and 0.842 [95% CI 0.678-1.000] for advanced adenoma and CRC stage I-IV, respectively.

CONCLUSION

kcnj12 and znf132 are two novel methylation biomarkers for CRC diagnosis. The 4-marker methylation model provides a new non-invasive choice for CRC screening and interception.

A two-tiered targeted proteomics approach to identify pre-diagnostic biomarkers of colorectal cancer risk

Colorectal cancer prognosis is dependent on stage, and measures to improve early detection are urgently needed. Using prospectively collected plasma samples from the population-based Northern Sweden Health and Disease Study, we evaluated protein biomarkers in relation to colorectal cancer risk. Applying a two-tiered approach, we analyzed 160 proteins in matched sequential samples from 58 incident colorectal cancer case-control pairs. Twenty-one proteins selected from both this discovery phase and the literature were then analyzed in a validation set of 450 case-control pairs. Odds ratios were estimated by conditional logistic regression. LASSO regression and ROC analysis were used for multi-marker analyses. In the main validation analysis, no proteins retained statistical significance. However, exploratory subgroup analyses showed associations between FGF-21 and colon cancer risk (multivariable OR per 1 SD: 1.23 95% CI 1.03-1.47) as well as between PPY and rectal cancer risk (multivariable OR per 1 SD: 1.47 95% CI 1.12-1.92). Adding protein markers to basic risk predictive models increased performance modestly. Our results highlight the challenge of developing biomarkers that are effective in the asymptomatic, prediagnostic window of opportunity for early detection of colorectal cancer. Distinguishing between cancer subtypes may improve prediction accuracy. However, single biomarkers or small panels may not be sufficient for effective precision screening.

Auto-antibodies to p53 and the Subsequent Development of Colorectal Cancer in a U.S. Prospective Cohort Consortium

BACKGROUND

Auto-antibodies to tumor suppressor p53 are found in a subset of patients with colorectal cancer. A recent prospective study in the United States has reported a significant 1.8-fold increased odds for colorectal cancer development with prediagnostic seropositivity to p53. In this study, we sought to examine this association in a U.S. colorectal cancer cohort consortium to evaluate the potential utility of p53 auto-antibodies as an early biomarker for colorectal cancer.

METHODS

Auto-antibodies to p53 were measured in prediagnostic blood samples of 3,702 incident colorectal cancer cases and 3,702 controls, matched by age, race, and sex, from 9 U.S. prospective cohorts. The association of seropositivity to p53 with colorectal cancer risk, overall and by time between blood draw and diagnosis, was determined by conditional logistic regression.

RESULTS

Overall, 5% of controls and 7% of cases were seropositive to p53, resulting in a statistically significant 33% increased colorectal cancer risk [odds ratio (OR), 1.33; 95% confidence interval (CI), 1.09-1.61]. By follow-up time, the association was only significant with colorectal cancer diagnoses within 4 years after blood draw (OR, 2.27; 95% CI, 1.62-3.19), but not thereafter (OR, 0.97; 95% CI, 0.76-1.24).

CONCLUSIONS

In this large consortium of prospective cohorts, we found that prediagnostic seropositivity to tumor suppressor p53 was significantly associated with an over 2-fold increased odds of developing colorectal cancer within 4 years after blood draw.

IMPACT

Our finding suggests that p53 seropositivity may not be a useful predictor of long-term colorectal cancer risk; however, it might be considered as a marker to aid in the early diagnosis of colorectal cancer.

Triage May Improve Selection to Colonoscopy and Reduce the Number of Unnecessary Colonoscopies

Implementation of population screening for colorectal cancer by direct colonoscopy or follow-up colonoscopy after a positive fecal blood test has challenged the overall capacity of bowel examinations. Certain countries are facing serious colonoscopy capacity constraints, which have led to waiting lists and long time latency of follow-up examinations. Various options for improvement are considered, including increased cut-off values of the fecal blood tests. Results from major clinical studies of blood-based, cancer-associated biomarkers have, however, led to focus on a Triage concept for improved selection to colonoscopy. The Triage test may include subject age, concentration of hemoglobin in a feces test and a combination of certain blood-based cancer-associated biomarkers. Recent results have indicated that Triage may reduce the requirements for colonoscopy by around 30%. Such results may be advantageous for the capacity, the healthcare budgets and in particular, the subjects, who do not need an unnecessary, unpleasant and risk-associated bowel examination.

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.

Serum SYPL1 is a promising diagnostic biomarker for colorectal cancer

BACKGROUND

At present, the overall sensitivity and specificity of blood biomarkers are insufficient for a diagnosis of colorectal cancer (CRC).

METHODS

We analyzed the serum synaptophysin like 1 (sSYPL1) in controls, adenoma patients, CRC patients, pre- and postoperative CRC patients by ELISA.

RESULTS

The upregulation of SYPL1 was confirmed in CRC tissues at both mRNA and protein levels. Consistently, sSYPL1 was significantly higher in CRC patients than in either controls (t = 14.50, P < 0.0001) or adenoma patients (t = 10.56, P < 0.0001) and was associated with lymph node invasion (χ² = 4.27, P = 0.039). ROC curves showed that sSYPL1 performed superbly in distinguishing CRC patients from controls (AUC: 0.9481; sensitivity: 86.09%, specificity: 91.01%) and adenoma (AUC: 0.8631; sensitivity: 98.68%, specificity: 78.08%). This performance was much better than that of carcinoembryonic antigen (CEA) or carbohydrate antigen 19-9 (CA19-9). Even for patients with low CEA levels (under 5 ng/mL), SYPL1 maintained the same high performance for identification of CRC. Furthermore, sSYPL1 levels declined significantly after radical surgery (t = 5.903, P < 0.0001).

CONCLUSION

sSYPL1 might be an outstanding marker for CRC diagnosis, especially for patients with low CEA levels.

Noninvasive Detection of Colorectal Carcinomas Using Serum Protein Biomarkers

BACKGROUND

A major roadblock to reducing the mortality of colorectal cancer (CRC) is prompt detection and treatment, and a simple blood test is likely to have higher compliance than all of the current methods. The purpose of this report is to examine the utility of a mass spectrometry-based blood serum protein biomarker test for detection of CRC.

MATERIALS AND METHODS

Blood was drawn from individuals (n = 213) before colonoscopy or from patients with nonmetastatic CRC (n = 50) before surgery. Proteins were isolated from the serum of patients using targeted liquid chromatography-tandem mass spectrometry. We designed a machine-learning statistical model to assess these proteins.

RESULTS

When considered individually, over 70% of the selected biomarkers showed significance by Mann-Whitney testing for distinguishing cancer-bearing cases from cancer-free cases. Using machine-learning methods, peptides derived from epidermal growth factor receptor and leucine-rich alpha-2-glycoprotein 1 were consistently identified as highly predictive for detecting CRC from cancer-free cases. A five-marker panel consisting of leucine-rich alpha-2-glycoprotein 1, epidermal growth factor receptor, inter-alpha-trypsin inhibitor heavy-chain family member 4, hemopexin, and superoxide dismutase 3 performed the best with 70% specificity at over 89% sensitivity (area under the curve = 0.86) in the validation set. For distinguishing regional from localized cancers, cross-validation within the training set showed that a panel of four proteins consisting of CD44 molecule, GC-vitamin D-binding protein, C-reactive protein, and inter-alpha-trypsin inhibitor heavy-chain family member 3 yielded the highest performance (area under the curve = 0.75).

CONCLUSIONS

The minimally invasive blood biomarker panels identified here could serve as screening/detection alternatives for CRC in a human population and potentially useful for staging of existing cancer.

Early Detection and Recurrence of Colorectal Adenomas by Combination of Eight Cancer-Associated Biomarkers in Plasma

INTRODUCTION

Plasma levels of eight combined proteins have shown value as biomarkers for detection of colorectal cancer (CRC). However, their value in identifying colorectal adenoma needs further evaluation. The aim was to evaluate the eight proteins (AFP, CA19-9, CEA, CyFra21-1, Ferritin, Galectin-3, hs-CRP and TIMP-1) in detection of high-risk adenoma (HRA) and in prediction of recurrence of adenoma. Furthermore, the discrimination between HRA and low-risk adenoma (LRA) or CRC lesions was evaluated.

METHODS

The study included 4698 individuals undergoing diagnostic colonoscopy. Automated ELISA platforms were used in the determination of protein levels in samples collected just before colonoscopy.

RESULTS

Univariably, five proteins (AFP, CEA, CyFra21-1, hs-CRP and TIMP-1), respectively, significantly discriminated individuals with HRA from individuals with non-malignant findings. Multivariably, the combination of CEA and hs-CRP improved performance; AUC= 0.63 (sensitivity=0.19 at specificity=0.90). CyFra21-1, Ferritin and TIMP-1 demonstrated significant discrimination between individuals with HRA and LRA in univariable analyses, respectively. Performance was improved in multivariable analysis; AUC=0.61 (sensitivity=0.13 at specificity=0.90). Discrimination between individuals with colorectal adenomas and healthy individuals was significant for CA19-9, CEA, hs-CRP and TIMP-1, respectively, in univariable analyses. Multivariable analysis improved performance; AUC=0.63 (sensitivity=0.17 at specificity=0.90). All proteins except AFP demonstrated significant discrimination between individuals with HRA and CRC. Combination of CEA, CyFra21-1, Ferritin, hs-CRP and TIMP-1 in multivariable analysis improved discrimination; AUC=0.78 (sensitivity=0.34 at specificity=0.90). Association between plasma levels of any of the eight proteins and recurrence of colorectal adenomas after endoscopic removal could not be demonstrated.

DISCUSSION

The protein panel shows a promising potential in detection of colorectal adenomas in general, but specifically of HRA. However, improvements are needed for the panel to be valuable as a screening test. Finally, plasma levels of the eight proteins were not predictive of recurrence of colorectal adenomas.

Serum CNPY2 isoform 2 represents a novel biomarker for early detection of colorectal cancer

Since early diagnosis is very important for treating CRC, we decided to detect peripheral serum canopy fibroblast growth factor signaling regulator 2 (CNPY2) isoform 2 to verify its diagnostic value for CRC patients. Serum samples were collected from 430 CRC patients and 201 healthy controls. Enzyme-linked immunosorbent assay (ELISA) detection kits for CNPY2 isoform 2 were generated and then applied to measure serum CNPY2 isoform 2 concentrations. Serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) were also measured. The median serum CNPY2 isoform 2 concentrations in all CRC patients were significantly higher than those in the healthy control group (all P<0.001). Those with stage I CRC presented the highest area under the receiver operating characteristic curve (AUC) for CNPY2 isoform 2 [0.707, 95% confidence interval (CI): 0.649-0.765, P<0.001]. The diagnostic efficiency of the combination of CNPY2 isoform 2, CEA and CA19-9 was significantly higher than that of each biomarker detected separately (all P<0.0167). Serum CNPY2 isoform 2 may be a valuable biomarker for the early detection of CRC and presents an improvement in the diagnostic efficiency by combination of CEA and CA19-9.

Evaluation and Validation of Plasma Proteins Using Two Different Protein Detection Methods for Early Detection of Colorectal Cancer

Objective: Plasma protein biomarkers could be an efficient alternative for population-based screening for early detection of colorectal cancer (CRC). The objective of this study was to evaluate and validate plasma proteins individually and as a signature for early detection of CRC. Methods: In a three-stage design, proteins were measured firstly by liquid chromatography/multiple reaction monitoring-mass spectrometry (LC/MRM-MS) and later by proximity extension assay (PEA) in a discovery set consisting of 96 newly diagnosed CRC cases and 94 controls free of neoplasms at screening colonoscopy. Two algorithms (one for each measurement method) were derived by Lasso regression and .632+ bootstrap based on 11 proteins that were included in both the LC/MRM-MS and PEA measurements. Additionally, another algorithm was constructed from the same eleven biomarkers plus amphireglin, the most promising protein marker in the PEA measurements that had not been available from the LC/MRM-MS measurements. Lastly the three prediction signatures were validated with PEA in independent samples of participants of screening colonoscopy (CRC (n = 56), advanced adenoma (n = 101), and participants free of neoplasm (n = 102)). Results: The same four proteins were included in all three prediction signatures; mannan binding lectin serine protease 1, osteopontin, serum paraoxonase lactonase 3 and transferrin receptor protein 1, and the third prediction signature additionally included amphiregulin. In the independent validation set from a true screening setting, the five-marker blood-based signature including AREG presented areas under the curves of 0.82 (95% CI, 0.74–0.89), 0.86 (95% CI, 0.77–0.92) and 0.76 (95% CI, 0.64–0.86) for all, early and late stages CRC, respectively. Conclusion: Two different measurement methods consistently identified four protein markers and an algorithm additionally including amphiregulin, a marker measured by PEA only, showed promising performance for detecting early stage CRC in an independent validation in a true screening setting. These proteins may be potential candidates for blood-based tests for early detection of CRC.

Systemic inflammation in colorectal cancer: Underlying factors, effects, and prognostic significance

Systemic inflammation is a marker of poor prognosis preoperatively present in around 20%-40% of colorectal cancer patients. The hallmarks of systemic inflammation include an increased production of proinflammatory cytokines and acute phase proteins that enter the circulation. While the low-level systemic inflammation is often clinically silent, its consequences are many and may ultimately lead to chronic cancer-associated wasting, cachexia. In this review, we discuss the pathogenesis of cancer-related systemic inflammation, explore the role of systemic inflammation in promoting cancer growth, escaping antitumor defense, and shifting metabolic pathways, and how these changes are related to less favorable outcome.

The clinical value of carcinoembryonic antigen for tumor metastasis assessment in lung cancer

Background

Carcinoembryonic antigen (CEA) as a diagnostic or prognostic marker has been widely studied in patients with lung cancer. However, the relationship between serum CEA and tumor metastasis in lung cancer remains controversial. This study aimed to investigate the ability of serum CEA to assess tumor metastasis in lung cancer patients.

Methods

We performed a retrospective analysis of 238 patients diagnosed with lung cancer from January to December 2016 at pneumology department of Dazhou Central Hospital (Dazhou, China). Serum CEA levels were quantified in each patient at the time of diagnosis of lung cancer. Metastasis was confirmed by computed tomography (CT), and/or positron emission tomography (PET) and/or surgery or other necessary detecting methods.

Results

Of the 213 patients eligible for final analysis, 128 were diagnosed with metastasis and 85 were diagnosed without metastasis. Compared to non-metastatic patients, the serum CEA was markedly higher in patients with metastasis (p < 0.001), and the area under the curve (AUC) was 0.724 (95% CI [0.654–0.793]). Subsequent analyses regarding the number and location of tumor metastases showed that CEA also had clinical value for multiple metastases versus single metastasis (AUC = 0.780, 95% CI [0.699–0.862]) and distant metastasis versus non-distant metastasis (AUC = 0.815, 95% CI [0.733–0.897]). In addition, we found that tumor size, histology diagnosis, age and gender had no impact on the assessment performance of CEA.

Conclusion

Our study suggested the serum CEA as a valuable marker for tumor metastases assessment in newly diagnosed lung cancer patients, which could have some implications in clinical application.

Fecal Immunochemical Tests for Colorectal Cancer Screening: Is Fecal Sampling from Multiple Sites Necessary?

Fecal immunochemical tests (FITs) for hemoglobin (Hb) are increasingly used for colorectal cancer (CRC) screening. Most FIT manufacturers instruct that fecal samples from multiple parts of one bowel movement should be obtained. Our aim was to compare the FIT diagnostic performance based on fecal samples from just one versus two different sites of one bowel movement. A total of 1141 participants of screening colonoscopy provided two fecal samples from two different sites of a single bowel movement for FIT analyses. There was no statistically significant difference in the diagnostic performance of the FIT when either one or both fecal samples were used for analysis, with area under the curve (AUC) for detecting CRC ranging from 0.94 (95% confidence interval (CI) 0.84–0.99) for one FIT to 0.95 (95%CI 0.86–0.99) for a geometric mean of two FITs. The manufacturers’ recommendation of sampling multiple sites of the stool aims to reduce intra-individual Hb variability and improve diagnostic performance. If no such improvement can be achieved, the recommendation for multiple-site sampling might have potential adverse effects on population adherence to FIT-based CRC screening. Our results point to a potential of increasing adherence to FIT screening by simplifying instructions for fecal sampling at no loss of the diagnostic performance.

An enrichment model using regular health examination data for early detection of colorectal cancer

Objective

Challenges remain in current practices of colorectal cancer (CRC) screening, such as low compliance, low specificities and expensive cost. This study aimed to identify high-risk groups for CRC from the general population using regular health examination data.

Methods

The study population consist of more than 7,000 CRC cases and more than 140,000 controls. Using regular health examination data, a model detecting CRC cases was derived by the classification and regression trees (CART) algorithm. Receiver operating characteristic (ROC) curve was applied to evaluate the performance of models. The robustness and generalization of the CART model were validated by independent datasets. In addition, the effectiveness of CART-based screening was compared with stool-based screening.

Results

After data quality control, 4,647 CRC cases and 133,898 controls free of colorectal neoplasms were used for downstream analysis. The final CART model based on four biomarkers (age, albumin, hematocrit and percent lymphocytes) was constructed. In the test set, the area under ROC curve (AUC) of the CART model was 0.88 [95% confidence interval (95% CI), 0.87-0.90] for detecting CRC. At the cutoff yielding 99.0% specificity, this model's sensitivity was 62.2% (95% CI, 58.1%-66.2%), thereby achieving a 63-fold enrichment of CRC cases. We validated the robustness of the method across subsets of test set with diverse CRC incidences, aging rates, genders ratio, distributions of tumor stages and locations, and data sources. Importantly, CART-based screening had the higher positive predictive value (1.6%) than fecal immunochemical test (0.3%).

Conclusions

As an alternative approach for the early detection of CRC, this study provides a low-cost method using regular health examination data to identify high-risk individuals for CRC for further examinations. The approach can promote early detection of CRC especially in developing countries such as China, where annual health examination is popular but regular CRC-specific screening is rare.

Branched rolling circle amplification method for measuring serum circulating microRNA levels for early breast cancer detection

Serum circulating microRNAs (c‐miRNAs) are serving as useful biomarkers for cancer diagnosis. Here, we describe the development of a one‐step branched rolling circle amplification (BRCA) method to measure serum c‐miRNAs levels for early diagnosis of breast cancer. Four c‐miRNAs, c‐miRNA16 (c‐miR‐16), c‐miRNA21 (c‐miR‐21), c‐miRNA155 (c‐miR‐155), and c‐miRNA195 (c‐miR‐195) were isolated from the serum of 49 breast cancer patients (stages I‐IV) and 19 healthy controls, and analyzed using one‐step BRCA. The serum levels of c‐miR16, c‐miR21, c‐miR155, and c‐miR195 were higher (P < 0.0001) in stage I breast cancer patients than healthy controls. These levels were also higher in several breast cancer molecular subtypes (HER‐2 over‐expression, Luminal A, Luminal B, and triple negative breast cancer) than in healthy control subjects. The diagnostic accuracy of c‐miR16, c‐miR21, c‐miR155, and c‐miR195 for early diagnosis of breast cancer was confirmed by receiver operating characteristic (ROC) curve assay. These results show that the BRCA method can be used to measure serum c‐miRNAs levels, and that this method has high accuracy, sensitivity, and specificity. Moreover, both BRCA approach and quantitative real‐time PCR (qRT‐PCR) method show that the serum levels of c‐miR16, c‐miR21, c‐miR155, and c‐miR195 could be used as biomarkers to improve the early diagnosis of breast cancer, and distinguish different breast cancer molecular subtypes.

Biomarker discovery study of inflammatory proteins for colorectal cancer early detection demonstrated importance of screening setting validation

OBJECTIVES

Most studies identifying inflammatory markers for early detection of colorectal cancer (CRC) were conducted using clinically manifest cases. We aimed to identify circulating inflammatory biomarkers for early detection of CRC and validate them in both a clinical setting and a true screening setting.

STUDY DESIGN AND SETTING

A total of 92 inflammatory proteins were quantified in baseline plasma samples from individuals clinically diagnosed with CRC and neoplasm-free controls matched on age and sex (training set). A multimarker panel was selected and evaluated in samples from another clinical setting (validation set C) and a screening setting (validation set S).

RESULTS

In the training set (N = 330), a five-biomarker signature was selected that provided an area under curve (AUC) of 0.85 and 60.9% sensitivity to detect CRC at 90% specificity. When this algorithm was applied to validation set C (N = 318), the AUC (0.80) and sensitivity (49.5%) at 90% specificity for CRC diagnosis were only slightly lower than those in the training set. By contrast, the diagnostic performance of the algorithm in validation set S (N = 126) from a true screening setting was much poorer, with an AUC of 0.59 and a sensitivity of 28.6% at 90% specificity.

CONCLUSIONS

An inflammation-related protein panel with apparently good diagnostic properties for CRC detection was identified and confirmed in an independent clinical validation set. However, the biomarker combination performed substantially worse in a validation sample from a true screening setting. Our results underline the importance of validation in screening settings subsequently to novel signature discovery for cancer early detection.

Pro-tumorigenic roles of fibroblast activation protein in cancer: back to the basics

Fibroblast activation protein (FAP) is a cell-surface serine protease that acts on various hormones and extracellular matrix components. FAP is highly upregulated in a wide variety of cancers, and is often used as a marker for pro-tumorigenic stroma. It has also been proposed as a molecular target of cancer therapies, and, especially in recent years, a great deal of research has gone into design and testing of diverse FAP-targeted treatments. Yet despite this growing field of research, our knowledge of FAP's basic biology and functional roles in various cancers has lagged behind its use as a tumor-stromal marker. In this review, we summarize and analyze recent advances in understanding the functions of FAP in cancer, most notably its prognostic value in various tumor types, cellular effects on various cell types, and potential as a therapeutic target. We highlight outstanding questions in the field, the answers to which could shape preclinical and clinical studies of FAP.

Systematic review of blood diagnostic markers in colorectal cancer

The purpose of this systematic review was to compare the diagnostic ability of blood markers for colorectal cancer (CRC). A systematic review of the literature for diagnostic blood markers for primary human colorectal cancer over the last 5 years was performed. The primary outcome was to assess the diagnostic ability of these markers in diagnosing colorectal cancer. The secondary outcome was to see whether the marker was compared to other markers. The tertiary outcome was to assess diagnostic ability in early versus late CRC, including stage IV disease. We identified 51 studies (29 prospective, 14 retrospective, and 8 meta-analyses). The markers were divided in broadly four groups: nucleic acids (RNA/DNA/messenger RNA/microRNAs), cytokines, antibodies, and proteins. The most promising circulating markers identified among the nucleid acids were NEAT_v2 non-coding RNA, SDC2 methylated DNA, and SEPT9 methylated DNA. The most promising cytokine to detect CRC was interleukin 8, and the most promising circulating proteins were CA11-19 glycoprotein and DC-SIGN/DC-SIGNR. Sensitivities of these markers for detecting primary colorectal carcinoma ranged from 70 to 98% and specificities from 84 to 98.7%. The best studied blood marker was SEPT9 methylated DNA, which showed great variability with sensitivities ranging from 48.2 to 95.6% and specificities from 80 to 98.9%, making its clinical applicability challenging. If combined with fecal immunochemical test (FIT), the sensitivity improved from 78 to 94% in detecting CRC. Methylated SEPT9, methylated SDC2, and -SIGN/DC-SIGNR protein had better sensitivity and specificity than CEA or CA 19-9. With the exception of SEPT9 which is currently being implemented as a screening test for CRC all other markers lacked reproducibility and standardization and were studied in relatively small population samples.

Evaluation of the circulating level of fibroblast activation protein α for diagnosis of esophageal squamous cell carcinoma

To evaluate whether circulating fibroblast activation protein α (FAPα) could serve as a biomarker for the diagnosis of esophageal squamous cell carcinoma (ESCC), enzyme-linked immunosorbent assay (ELISA) was used to detect plasma FAPα in 556 participants including ESCC group, benign esophageal disease group, healthy controls and other cancer controls group. The levels of plasma FAPα were significantly decreased in ESCC patients (P < 0.001) and showed a positive correlation with HDL-C levels (R = 0.372, P < 0.001). The sensitivity and specificity of plasma FAPα were 56.1% and 85.6% based on the optimal cut-off (49.04 ng/ml, AUC = 0.714). The combination of FAPα and the traditional biomarkers (CEA, CYFR211 and SCCA) improved the sensitivity (41.5%) without compromising the specificity (95.0%). Contradictorily, the immunohistochemical staining revealed the overexpression of FAPα in stroma of ESCC tissues. So the source of soluble FAPα was further explored by qRT-PCR, Western blotting, ELISA and immunoprecipitation in fibroblast cell lines and mouse xenograft models. We found that the plasma FAPα was not correlated with the FAPα expressed in tumor, and the multi-organ might contribute to the circulating levels of FAPα including skeletal muscle, liver and bone marrow. These results indicated that the low plasma FAPα level might due to the systemic reaction to the presence of tumor and circulating FAPα level might be a potential indicator for diagnosing ESCC.

Myoferlin is a novel exosomal protein and functional regulator of cancer-derived exosomes

Exosomes are communication mediators participating in the intercellular exchange of proteins, metabolites and nucleic acids. Recent studies have demonstrated that exosomes are characterized by a unique proteomic composition that is distinct from the cellular one. The mechanisms responsible for determining the proteome content of the exosomes remain however obscure. In the current study we employ ultrastructural approach to validate a novel exosomal protein myoferlin. This is a multiple C2-domain containing protein, known for its conserved physiological function in endocytosis and vesicle fusion biology. Emerging studies demonstrate that myoferlin is frequently overexpressed in cancer, where it promotes cancer cell migration and invasion. Our data expand these findings by showing that myoferlin is a general component of cancer cell derived exosomes from different breast and pancreatic cancer cell lines. Using proteomic analysis, we demonstrate for the first time that myoferlin depletion in cancer cells leads to a significantly modulated exosomal protein load. Such myoferlin-depleted exosomes were also functionally deficient as shown by their reduced capacity to transfer nucleic acids to human endothelial cells (HUVEC). Beyond this, myoferlin-depleted cancer exosomes also had a significantly reduced ability to induce migration and proliferation of HUVEC. The present study highlights myoferlin as a new functional player in exosome biology, calling for novel strategies to target this emerging oncogene in human cancer.

Blood-Based Protein Signatures for Early Detection of Colorectal Cancer: A Systematic Review

OBJECTIVES

Blood-based proteins might be an attractive option for early detection of colorectal cancer (CRC), but individually they are unlikely to achieve the diagnostic performance required for population based screening. We aimed at summarizing current evidence of diagnostic performance of signatures based on multiple proteins for early detection of CRC.

METHODS

A systematic literature review adhering to the PRISMA (preferred reporting items for systematic reviews and meta-analysis) guidelines was performed. PubMed and Web of Science databases were searched for potentially relevant studies published until 28th August, 2017. Relevant studies were identified by predefined eligibility criteria. Estimates of indicators of diagnostic performance such as sensitivity, specificity, and the area under the curve (AUC), along with information on validation and other key methodological procedures were extracted. Study quality was assessed by a QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2) instrument tool.

RESULTS

Thirty six eligible studies with numbers of CRC cases ranging from 23 to 512 and the number of proteins included in signatures ranged from 3 to 13 were identified. Reported Youden's Index and AUC ranged from 0.19 to 0.95 and from 0.62 to 0.996, respectively. However most studies, especially those reporting better diagnostic performance, were conducted in clinical rather than screening setting and many studies lacked any internal or external validation of identified algorithm.

CONCLUSIONS

Blood-based tests using signatures of multiple proteins may be a promising approach for non-invasive CRC screening. However, promising signatures identified in clinical settings still require rigorous evaluation in large studies conducted in true screening setting.

Prospective evaluation of 64 serum autoantibodies as biomarkers for early detection of colorectal cancer in a true screening setting

Novel blood-based screening tests are strongly desirable for early detection of colorectal cancer (CRC). We aimed to identify and evaluate autoantibodies against tumor-associated antigens as biomarkers for early detection of CRC. 380 clinically identified CRC patients and samples of participants with selected findings from a cohort of screening colonoscopy participants in 2005–2013 (N=6826) were included in this analysis. Sixty-four serum autoantibody markers were measured by multiplex bead-based serological assays. A two-step approach with selection of biomarkers in a training set, and validation of findings in a validation set, the latter exclusively including participants from the screening setting, was applied. Anti-MAGEA4 exhibited the highest sensitivity for detecting early stage CRC and advanced adenoma. Multi-marker combinations substantially increased sensitivity at the price of a moderate loss of specificity. Anti-TP53, anti-IMPDH2, anti-MDM2 and anti-MAGEA4 were consistently included in the best-performing 4-, 5-, and 6-marker combinations. This four-marker panel yielded a sensitivity of 26% (95% CI, 13–45%) for early stage CRC at a specificity of 90% (95% CI, 83–94%) in the validation set. Notably, it also detected 20% (95% CI, 13–29%) of advanced adenomas. Taken together, the identified biomarkers could contribute to the development of a useful multi-marker blood-based test for CRC early detection.

Fecal immunochemical tests in combination with blood tests for colorectal cancer and advanced adenoma detection-systematic review

Background

Colorectal cancer (CRC) is a common but largely preventable cancer. Although fecal immunochemical tests (FITs) detect the majority of CRCs, they miss some of the cancers and most advanced adenomas (AAs). The potential of blood tests in complementing FITs for the detection of CRC or AA has not yet been systematically investigated.

Methods

We conducted a systematic review of performance of FIT combined with an additional blood test for CRC and AA detection versus FIT alone. PubMed and Web of Science were searched until June 9, 2017.

Results

Some markers substantially increased sensitivity for CRC when combined with FIT, albeit typically at a major loss of specificity. For AA, no relevant increase in sensitivity could be achieved.

Conclusion

Combining FIT and blood tests might be a promising approach to enhance sensitivity of CRC screening, but comprehensive evaluation of promising marker combinations in screening populations is needed.

Serological biomarkers in triage of FIT-positive subjects?

FIT-based colorectal cancer screening has been implemented in many countries including Denmark, where 916 colorectal cancer and 4468 high- or medium-risk adenoma patients were identified within April-December 2014, among 16,806 subjects with a positive FIT test. Screening increases the overall requirements for colonoscopy, which may challenge the current capacity. Some countries have increased their initial FIT cut-off level in order to comply with lack of colonoscopy capacity. Many patients with neoplasia will not be detected, however, by using increased FIT cut-off levels. The number of patients with neoplastic lesions missed by increased cut-off levels appears to be much higher than expected. Therefore, tests that identify those patients missed by increased FIT cut-off levels must be developed. Preliminary results of determination of one of several biomarker entities currently under investigation show that nucleosome blood tests may be one option for identifying some of these patients. Implementation of a triage test consisting of FIT, blood-based biomarkers and plus/minus colonoscopy is suggested to identify subjects with FIT levels between the initial and the increased cut-off level that must be offered colonoscopy. In addition, triage may reduce the frequency of unnecessary colonoscopies by 25%.

Fusobacterium and colorectal cancer: causal factor or passenger? Results from a large colorectal cancer screening study

Colorectal cancer is a leading cause of morbidity and mortality worldwide in both men and women. The gut microbiome is increasingly recognized as having an important role in human health and disease. Fusobacterium has been identified in former studies as a leading gut bacterium associated with colorectal cancer, but it is still not clear if it plays an oncogenic role. In the current study, fecal samples were collected prior to bowel preparation from participants of screening colonoscopy in the German BliTz study. Using 16S rRNA gene analysis, we examined the presence and relative abundance of Fusobacterium in fecal samples from 500 participants, including 46, 113, 110 and 231 individuals with colorectal cancer, advanced adenomas, non-advanced adenomas and without any neoplasms, respectively. We found that the abundance of Fusobacterium in feces was strongly associated with the presence of colorectal cancer (P-value < 0.0001). This was confirmed by PCR at the species level for Fusobacterium nucleatum. However, no association was seen with the presence of advanced adenomas (P-value = 0.80) or non-advanced adenomas (P-value = 0.80), nor were there any associations observed with dietary or lifestyle habits. Although a causal role cannot be ruled out, our observations, based on fecal microbiome, support the hypothesis that Fusobacterium is a passenger that multiplies in the more favorable conditions caused by the malignant tumor rather than a causal factor in colorectal cancer development.

A synthetic urinary probe-coated nanoparticles sensitive to fibroblast activation protein α for solid tumor diagnosis

We developed fibroblast activation protein α (FAPα)-sensitive magnetic iron oxide nanoparticles (MNPs) by conjugating a substrate-reporter tandem peptide as a synthetic biomarker to the surface of MNPs (marker-MNPs). In vitro, the marker-MNPs showed stability when treated with serum or urine and exhibited high susceptibility and specificity for FAPα enzyme and 3T3/FAPα cell line. Furthermore, the marker-MNPs were administered to esophageal squamous cell carcinoma xenograft tumor mice; they reached the tumor tissues in the mice, where they were cleaved effectively by the local overexpressed FAPα to release the reporter peptide and filter it into the urine. The tumor targeting and biodistribution of marker-MNPs were verified by in vivo imaging. The cleaved reporter peptides in urine detected by enzyme-linked immunosorbent assay have high diagnostic accuracy for esophageal squamous cell carcinoma (area under the receiver-operating characteristic curve =1.0). Our study implies a promising strategy of utilizing the low-cost and noninvasive synthetic urinary probe–coated nanoparticles for the diagnosis of FAPα-positive solid tumors, except for in renal cancer.

Detection of colorectal neoplasia: Combination of eight blood-based, cancer-associated protein biomarkers

Serological biomarkers may be an option for early detection of colorectal cancer (CRC). The present study assessed eight cancer-associated protein biomarkers in plasma from subjects undergoing first time ever colonoscopy due to symptoms attributable to colorectal neoplasia. Plasma AFP, CA19-9, CEA, hs-CRP, CyFra21-1, Ferritin, Galectin-3 and TIMP-1 were determined in EDTA-plasma using the Abbott ARCHITECT® automated immunoassay platform. Primary endpoints were detection of (i) CRC and high-risk adenoma and (ii) CRC. Logistic regression was performed. Final reduced models were constructed selecting the four biomarkers with the highest likelihood scores. Subjects (N = 4,698) were consecutively included during 2010-2012. Colonoscopy detected 512 CRC patients, 319 colonic cancer and 193 rectal cancer. Extra colonic malignancies were detected in 177 patients, 689 had adenomas of which 399 were high-risk, 1,342 had nonneoplastic bowell disease and 1,978 subjects had 'clean' colorectum. Univariable analysis demonstrated that all biomarkers were statistically significant. Multivariate logistic regression demonstrated that the blood-based biomarkers in combination significantly predicted the endpoints. The reduced model resulted in the selection of CEA, hs-CRP, CyFra21-1 and Ferritin for the two endpoints; AUCs were 0.76 and 0.84, respectively. The postive predictive value at 90% sensitivity was 25% for endpoint 1 and the negative predictive value was 93%. For endpoint 2, the postive predictive value was 18% and the negative predictive value was 97%. Combinations of serological protein biomarkers provided a significant identification of subjects with high risk of the presence of colorectal neoplasia. The present set of biomarkers could become important adjunct in early detection of CRC.

Epigenome-wide discovery and evaluation of leukocyte DNA methylation markers for the detection of colorectal cancer in a screening setting

Background

Colorectal cancer (CRC) is the third most common cancer worldwide. If detected at an early stage, prognosis is good. Despite increasing evidence for the benefits of implemented screening programs, such as screening colonoscopy, compliance is rather low. Hence there is demand for non-invasive tests for the early detection of CRC with high acceptance in population-wide screening. The objective of this study was to identify and evaluate leukocyte DNA methylation patterns as a potential biomarker for early detection of CRC.

Methods

Blood samples of patients scheduled for a screening colonoscopy were collected before the procedure. Additionally, blood samples from CRC cases recruited in a clinical setting were collected. DNA was extracted from leukocytes, and DNA methylation was measured with the Infinium 450K BeadChip. In total, 46 CRC cases and 140 controls from the screening setting and 93 CRC cases from the clinical setting were measured.

Results

An epigenome-wide discovery revealed two CpG sites in the promoter region of KIAA1549L that were significantly differentially methylated between cases and controls. A third marker in the body region of BCL2 was discovered in a candidate approach testing biomarkers reported in the literature. Logistic regression models built on these three markers yielded an optimism-corrected c-statistic of 0.69 in the screening setting and 0.73 in the clinical setting.

Conclusions

Although diagnostic performance of the DNA methylation signature identified in this first epigenome-wide association study of leukocyte DNA methylation with CRC in a screening setting is not competitive with established screening tests, the identified markers may contribute to multimarker panels for early detection of CRC.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-017-0322-x) contains supplementary material, which is available to authorized users.

Evaluation of serum nucleoside diphosphate kinase A for the detection of colorectal cancer

We previously described the over-expression of nucleoside diphosphate kinase A (NDKA) in tumours and serum from colorectal cancer (CRC) patients, suggesting its use as biomarker. In this study we evaluated the diagnostic accuracy of serum NDKA to detect advanced neoplasia (CRC or advanced adenomas). Furthermore, the performance of NDKA was compared with the faecal immunochemical test (FIT). The study population included a case-control cohort and a screening cohort (511 asymptomatic first-degree relatives of CRC patients that underwent a colonoscopy and a FIT). Serum NDKA was elevated in CRC patients in the case-control cohort (p = 0.002). In the screening cohort, NDKA levels were higher for advanced adenomas (p = 0.010) and advanced neoplasia (p = 0.006) compared to no neoplasia. Moreover, elevated NDKA was associated with severe characteristics of adenomas (≥3 lesions, size ≥ 1 cm or villous component). Setting specificity to 85%, NDKA showed a sensitivity of 30.19% and 29.82% for advanced adenomas and advanced neoplasia, respectively. NDKA combined with FIT (100 ng/mL cut-off) detected advanced adenomas and advanced neoplasia with 45.28% and 49.12% sensitivity, with specificity close to 90%. The combination of serum NDKA and FIT can improve the detection of advanced neoplasia, mainly for lesions located on the proximal colon, in asymptomatic individuals with CRC family-risk.