Early Detection of Colon Cancer

Dietary, addictive and habitual factors, and risk of colorectal cancer

BACKGROUND

In Pakistan, the incidence of colorectal cancer (CRC) has sharply increased in recent years. Although several studies have reported global risk factors for CRC, no study has been conducted in Khyber Pakhtunkhwa (KPK), Pakistan, to investigate the risk factors associated with the increased CRC burden in this population.

OBJECTIVES

Therefore, we conducted a clinical survey using a case-control study design to explore the risk factors associatd with CRC.

METHODS

In the present study, one control was enrolled for each case. Both cases and controls were asked to complete a questionnaire to gather data. We analyzed all data using SPSS.

RESULTS

Our study found that certain dietary factors, such as consuming fast food (OR: 3.0; P = 0.0001) and reusing ghee (OR: 2.45; P = 0.0001) and oil (OR: 4.30; P = 0.0001), increase the risk of CRC. Additionally, use of tobacco products like smoking cigarettes (OR: 1.91; P = 0.0001) and using snuff (OR: 3.72; P = 0.0001) significantly increases the risk of CRC. Certain habitual factors, including binge eating (OR: 2.42; P = 0.0001) and spending excessive time watching TV (OR: 1.98; P = 0.0001), also increase the odds of developing CRC. However, our study also identified some protective factors against CRC, such as consuming vegetables (OR: .41; P = 0.0001), developing healthy eating habits (OR: .61; P = 0.0001), and maintaining regular sleeping patterns (OR: .45; P = 0.0001).

CONCLUSION

Given these findings, targeted health education is necessary to prevent the increase in CRC in this area. We also recommend developing and enforcing appropriate control guidelines for cancer risk factors to curb the incidence of CRC.

Recent advancements in biosensor designs toward the detection of intestine cancer miRNA biomarkers

Cancer diagnosis and treatment have been of broad interest among scientists in the last decades due to the high death rate, widespread occurrence, and recurrence after treatment. The survival rate of cancer patients depends greatly on early detection and appropriate treatments. Therefore developing new technologies applicable to sensitive and specific methods of cancer detection is an inevitable task for cancer researchers. Abnormal miRNA expression is contributed to severe diseases such as cancers and since their expression level and type differ strictly during carcinogenesis and later metastasis and treatments, the improved detection accuracy of these miRNAs would undoubtedly lead to early diagnosis, prognosis, and targeted therapy. Biosensors are accurate and straightforward analytical devices that have had practical applications especially in the last decade. Their domain is still growing through a combination of attractive nanomaterials and amplification methods, leading to innovative biosensing platforms for the efficient detection of miRNAs as diagnostic and prognostic biomarkers. In this review, we will provide the recent developments in biosensors to detect intestine cancer miRNA biomarkers and also discuss the challenges and outcomings of this field.

A comparative examination of colorectal cancer burden in European Union, 1990-2019: Estimates from Global Burden of Disease 2019 Study

AIM

This study examines the burden of colorectal cancer (CRC) in European Union (EU) countries in the last 3 decades.

METHODS

The data pertaining to CRC burden were procured from the Global Burden of Disease 2019 Study for 28 EU countries (including United Kingdom) for the period 1990-2019. The age-standardized rates of CRC were utilized to compare the country-wise burden and joinpoint regression models were applied to examine the trends.

RESULTS

In EU, CRC incident cases increased by 70.2% from 261,306 to 444,872 and deaths increased by 36.8% from 155,823 to 213,174 between 1990 and 2019. The age-standardized incidence rate (ASIR) increased by 11.9% from 37.8/100,000 to 42.3/100,000 between 1990 and 2019; in contrast, the age-standardized mortality rate (ASMR) decreased by 16.9% (1990: 22.4/100,000; 2019: 18.6/100,000) and age-standardized DALYs rate (ASDALR) decreased by 18.6% (1990: 472.9/100,000; 2019: 385.1/100,000) in the study period. In 2019, Hungary was the leading country in terms of ASMR (28.6/100,000) and ASDALR (630.3/100,000), and Lithuania (29.2/100,000) had the lowest ASIR, whereas Finland had the lowest ASMR (12.3/100,000) and ASDALR (253.6/100,000) in 2019.

CONCLUSION

CRC incidence is increasing in EU and mortality rates, although decreasing, are still unacceptably high. CRC control efforts must be focused around early detection using screening and prevention through reduction of modifiable risk factors. Increasing CRC incidence rates in young adults in recent years requires more research to pinpoint risk factors, and there must be more awareness of this recent development among general public and clinicians.

Regulation of signal transduction pathways in colorectal cancer: implications for therapeutic resistance

Resistance to anti-cancer treatments is a critical and widespread health issue that has brought serious impacts on lives, the economy and public policies. Mounting research has suggested that a selected spectrum of patients with advanced colorectal cancer (CRC) tend to respond poorly to both chemotherapeutic and targeted therapeutic regimens. Drug resistance in tumours can occur in an intrinsic or acquired manner, rendering cancer cells insensitive to the treatment of anti-cancer therapies. Multiple factors have been associated with drug resistance. The most well-established factors are the emergence of cancer stem cell-like properties and overexpression of ABC transporters that mediate drug efflux. Besides, there is emerging evidence that signalling pathways that modulate cell survival and drug metabolism play major roles in the maintenance of multidrug resistance in CRC. This article reviews drug resistance in CRC as a result of alterations in the MAPK, PI3K/PKB, Wnt/β-catenin and Notch pathways.

Health literacy and cancer screening behaviors among community-dwelling female adults in Taiwan

This study was designed to explore the association among health literacy and cancer screening behaviors in Taiwanese females. A total of 353 community-dwelling females were recruited in this cross-sectional study from February to October 2015. Demographic, socioeconomic and personal behavior variables including physical activity, community activity, smoking, alcohol consumption, and betel nut chewing were recorded. Health literacy was evaluated using the Mandarin version of the European Health Literacy Survey Questionnaire. Data on screening behaviors for cervical, breast and colorectal cancers were confirmed by the Taiwanese National eHealth Database. Most respondents with inadequate or problematic general health literacy had no or irregular screening behaviors for cervical, breast and colorectal cancers. In multivariable regression analysis, women with inadequate health literacy were at a greater risk (Odds ratio = 5.71; 95% CI: 1.40-23.26) of having no previous Pap smear screening or >3 years screening interval regardless of education level. However, this association was not detected for breast or colorectal cancer. Women with inadequate health literacy were more likely to have irregular cervical cancer screening, however no associations among health literacy and breast or colorectal cancer were detected. The impact of health literacy on cancer screening behavior warrants further attention and research.

Diagnostic Value of Combining miRNAs, CEA Measurement and the FOBT in Colorectal Cancer Screening

Introduction

Colorectal cancer (CRC) is one of the most common illnesses that seriously threatens human health; many papers have reported that microRNAs (miRNAs) are promising biomarkers for cancer detection. However, miRNAs have not been used in clinical practice even though they are superior to the currently used screening tools, such as the fecal occult blood test (FOBT) and carcinoembryonic antigen (CEA) measurement.

Methods

In this study, we focused on the usefulness of a panel of miRNAs and the combination of miRNAs with the FOBT and CEA measurement, the currently used general diagnosis methods, to improve the accuracy of CRC diagnosis.

Results

The results showed that the miRNA panel has great potential value as a diagnostic biomarker with high specificity and sensitivity, and further analysis demonstrated that the miRNA panel had higher sensitivity and specificity than the FOBT and CEA measurement, even when these methods were combined. More importantly, although the miRNA panel is superior to the FOBT and CEA measurement, it cannot replace them.

Conclusions

In this research, we investigated whether complementarity exists between the miRNA panel and the FOBT and CEA measurement for CRC diagnosis. Interestingly, the results indicated that the FOBT and CEA measurement could improve the positivity rate of the miRNA panel as a biomarker and vice versa.

Antitumorigenic Effects of Inhibiting Ephrin Receptor Kinase Signaling by GLPG1790 against Colorectal Cancer Cell Lines In Vitro and In Vivo

Erythropoietin-producing hepatocellular receptors (Eph) promote the onset and sustain the progression of cancers such as colorectal cancer (CRC), in which the A2 subtype of Eph receptor expression has been shown to correlate with a poor prognosis and has been identified as a promising therapeutic target. Herein, we investigated, in vitro and in vivo, the effects of treatment with GLPG1790, a potent pan-Eph inhibitor. The small molecule has selective activity against the EphA2 isoform in human HCT116 and HCT15 CRC cell lines expressing a constitutively active form of RAS concurrently with a wild-type or mutant form of p53, respectively. GLPG1790 reduced EPHA2 phosphorylation/activation and induced G₁/S cell-cycle growth arrest by downregulating the expression of cyclin E and PCNA, while upregulating p21^Waf1/Cip1 and p27^Cip/Kip. The inhibition of ephrin signaling induced quiescence in HCT15 and senescence in HCT116 cells. While investigating the role of CRC-related, pro-oncogenic p53 and RAS pathways, we found that GLPG1790 upregulated p53 expression and that silencing p53 or inhibiting RAS (human rat sarcoma)/ERKs (extracellular signal-regulated kinase) signaling restrained the ability of GLPG1790 to induce senescence in HCT116 cells. On the other hand, HCT15 silencing of p53 predisposed cells to GLPG1790-induced senescence, whilst no effects of ERK inhibition were observed. Finally, GLPG1790 hindered the epithelial-mesenchymal transition, reduced the migratory capacities of CRC, and affected tumor formation in xenograft models in vivo more efficiently using HCT116 than HCT15 for xenografts. Taken together, our data suggest the therapeutic potential of GLPG1790 as a signal transduction-based therapeutic strategy in to treat CRC.

Alterations in folate-dependent one-carbon metabolism as colon cell transition from normal to cancerous

Folate-dependent one-carbon cycle metabolism (FOCM) plays a critical role in maintaining genomic stability through regulating DNA biosynthesis, repair and methylation. Folate metabolites as well as other metabolites in the FOCM are hypothesized to be altered when cells transition from normal to cancerous state. Using cells at different stages in their development into colorectal cancer, the FOCM metabolites were profiled as an effort to phenotype the cells, and the metabolite levels were compared to the expressions of related genes. Here, we investigate whether there is a correlation between the metabolite levels, DNA methylation levels and the expression of the related genes that drive the levels of these metabolites. Using CRL1459, APC10.1, HCT116 and Caco-2, we show for the first time that FOCM metabolites correlate with the gene expression patterns. These differences follow a trend that may facilitate distinguishing colon cells at the different stages as they transition into cancerous state. The folate distribution and methionine levels were found to be key in determining the staging of the colon cells in CRC development. Also, expression of CBS, MTRR and MAT genes may facilitate distinguishing between untransformed and transformed colon cells.

Exploratory metabolomic study to identify blood-based biomarkers as a potential screen for colorectal cancer

INTRODUCTION

colorectal cancer (CRC) continues to be difficult to diagnose due to the lack of reliable and predictive biomarkers.

OBJECTIVE

to identify blood-based biomarkers that can be used to distinguish CRC cases from controls.

METHODS

a workflow for untargeted followed by targeted metabolic profiling was conducted on the plasma samples of 26 CRC cases and ten healthy volunteers (controls) using liquid chromatography-mass spectrometry (LCMS). The data acquired in the untargeted scan was processed and analyzed using MarkerView™ software. The significantly different ions that distinguish CRC cases from the controls were identified using a mass-based human metabolome search. The result was further used to inform the targeted scan workflow.

RESULTS

the untargeted scan yielded putative biomarkers some of which were related to the folate-dependent one-carbon metabolism (FOCM). Analysis of the targeted scan found the plasma levels of nine FOCM metabolites to be significantly different between cases and controls. The classification models of the cases and controls, in both the targeted and untargeted approaches, each yielded a 97.2% success rate after cross-validation.

CONCLUSION

we have identified plasma metabolites with screening potential to discriminate between CRC cases and controls.

Metabolomics Biomarkers for Detection of Colorectal Neoplasms: A Systematic Review

BACKGROUND

Several approaches have been suggested to be useful in the early detection of colorectal neoplasms. Since metabolites are closely related to the phenotype and are available from different human bio-fluids, metabolomics are candidates for non-invasive early detection of colorectal neoplasms.

OBJECTIVES

We aimed to summarize current knowledge on performance characteristics of metabolomics biomarkers that are potentially applicable in a screening setting for the early detection of colorectal neoplasms.

DESIGN

We conducted a systematic literature search in PubMed and Web of Science and searched for biomarkers for the early detection of colorectal neoplasms in easy-to-collect human bio-fluids. Information on study design and performance characteristics for diagnostic accuracy was extracted.

RESULTS

Finally, we included 41 studies in our analysis investigating biomarkers in different bio-fluids (blood, urine, and feces). Although single metabolites mostly had limited ability to distinguish people with and without colorectal neoplasms, promising results were reported for metabolite panels, especially amino acid panels in blood samples, as well as nucleosides in urine samples in several studies. However, validation of the results is limited.

CONCLUSIONS

Panels of metabolites consisting of amino acids in blood and nucleosides in urinary samples might be useful biomarkers for early detection of advanced colorectal neoplasms. However, to make metabolomic biomarkers clinically applicable, future research in larger studies and external validation of the results is required.

Quantitative mass spectrometry analysis reveals a panel of nine proteins as diagnostic markers for colon adenocarcinomas

Adenocarcinomas are cancers originating from the gland forming cells of the colon and rectal lining, and are known to be the most common type of colorectal cancers. The current diagnosis strategies for colorectal cancers include biopsy, laboratory tests, and colonoscopy which are time consuming. Identification of protein biomarkers could aid in the detection of colon adenocarcinomas (CACs). In this study, tissue proteome of colon adenocarcinomas (n = 11) was compared with the matched control specimens (n = 11) using isobaric tags for relative and absolute quantitation (iTRAQ) based liquid chromatography-mass spectrometry (LC-MS/MS) approach. A list of 285 significantly altered proteins was identified in colon adenocarcinomas as compared to its matched controls, which are associated with growth and malignancy of the tumors. Protein interaction analysis revealed the association of altered proteins in colon adenocarcinomas with various transcription factors and their targets. A panel of nine proteins was validated using multiple reaction monitoring (MRM). Additionally, S100A9 was also validated using immunoblotting. The identified panel of proteins may serve as potential biomarkers and thereby aid in the detection of colon adenocarcinomas.

Screening for Colorectal Cancer Is Associated With Lower Disease Stage: A Population-Based Study

BACKGROUND & AIMS

Screening for colorectal cancer (CRC) using fecal occult blood tests (FOBT) is associated with reduced CRC incidence and mortality. Population-based FOBT screening has led to identification of CRCs at earlier stages and longer patient survival times. We investigated the stage distribution of CRCs detected by colonoscopy in a large outpatient cohort.

METHODS

We performed a retrospective analysis of colonoscopies performed on 524,954 outpatients (age, ≥55 y) in Germany from January 2006 through December 2009. Patients with chronic inflammatory bowel diseases, and those with a personal history of adenoma or CRC, were excluded. Colonoscopy findings were categorized on the basis of the most advanced lesion found; histologic samples were obtained from all patients with suspected cancer and analyzed. Cancers were staged based on Union Internationale Contre le Cancer criteria. We analyzed absolute and relative frequencies of CRCs identified and tumor stages for patients who underwent colonoscopy for screening, evaluation of a positive FOBT, and evaluation of symptoms.

RESULTS

Of the 6065 CRCs identified, 1750 were found in the screening group, 1075 in subjects with positive FOBT, and 3240 in patients with symptoms. Stage I CRC was detected more frequently in subjects who received screening colonoscopies (41.15%) or in those with positive FOBT (39.10%), than in individuals with symptoms (24.42%; P < .001). In contrast, the detection rates of stage IV CRC were 10.67%, 10.76%, and 18.64%, respectively (P < .001). We observed a shift toward lower T stages in the screening and FOBT work-up groups compared with the group with symptoms. Compared with subjects with symptoms, the odds of diagnosing CRC at an advanced stage were significantly lower in the screening group (odds ratio, 0.533; 95% confidence interval, 0.451-0.631) and the FOBT work-up group (odds ratio, 0.570; 95% confidence interval, 0.469-0.694).

CONCLUSIONS

In this large population-based study, CRC detected by colonoscopies performed for screening and evaluation of positive FOBTs had a lower stage than those diagnosed by colonoscopies in symptomatic patients. These findings support the value of screening colonoscopy to reduce the burden of CRC.

Simultaneous Analysis of SEPT9 Promoter Methylation Status, Micronuclei Frequency, and Folate-Related Gene Polymorphisms: The Potential for a Novel Blood-Based Colorectal Cancer Biomarker

One challenge in colorectal cancer (CRC) is identifying novel biomarkers to be introduced in screening programs. The present study investigated the promoter methylation status of the SEPT9 gene in peripheral blood samples of subjects' positive fecal occult blood test (FOBT). In order to add new insights, we investigated the association between SEPT9 promoter methylation and micronuclei frequency, and polymorphisms in the folate-related pathway genes. SEPT9 promoter methylation, micronuclei frequency, and genotypes were evaluated on 74 individuals' FOBT positive. Individuals were subjected to a colonoscopy that provided written informed consent for study participation. SEPT9 promoter methylation status was significantly lower in the CRC group than controls (p = 0.0006). In contrast, the CaCo2 cell-line, analyzed as a tissue specific model of colon adenocarcinoma, showed a significantly higher percentage of SEPT9 promoter methylation compared to the CRC group (p < 0.0001). Linear regression analysis showed an inverse correlation between micronuclei frequency and the decrease in the methylation levels of SEPT9 promoter region among CRC patients (β = -0.926, p = 0.0001). With regard to genotype analysis, we showed the involvement of the DHFR polymorphism (rs70991108) in SEPT9 promoter methylation level in CRC patients only. In particular, the presence of at least one 19 bp del allele significantly correlates with decreased SEPT9 promoter methylation, compared to the 19 bp ins/ins genotype (p = 0.007). While remaining aware of the strengths and limitations of the study, this represents the first evidence of a novel approach for the early detection of CRC, using SEPT9 promoter methylation, micronuclei frequency and genotypes, with the potential to improve CRC risk assessment.

Current Challenges in Volatile Organic Compounds Analysis as Potential Biomarkers of Cancer

An early diagnosis and appropriate treatment are crucial in reducing mortality among people suffering from cancer. There is a lack of characteristic early clinical symptoms in most forms of cancer, which highlights the importance of investigating new methods for its early detection. One of the most promising methods is the analysis of volatile organic compounds (VOCs). VOCs are a diverse group of carbon-based chemicals that are present in exhaled breath and biofluids and may be collected from the headspace of these matrices. Different patterns of VOCs have been correlated with various diseases, cancer among them. Studies have also shown that cancer cells in vitro produce or consume specific VOCs that can serve as potential biomarkers that differentiate them from noncancerous cells. This review identifies the current challenges in the investigation of VOCs as potential cancer biomarkers, by the critical evaluation of available matrices for the in vivo and in vitro approaches in this field and by comparison of the main extraction and detection techniques that have been applied to date in this area of study. It also summarises complementary in vivo, ex vivo, and in vitro studies conducted to date in order to try to identify volatile biomarkers of cancer.

PAX1 methylation as a potential biomarker for cervical cancer screening

OBJECTIVES

DNA methylation is a potential biomarker for early cancer detection. Previous studies suggested that the methylations of several genes are promising markers for the detection of cervical intraepithelial neoplasia at grade III or worse (CIN3+). The purpose of the present study was to explore the feasibility of these DNA methylation testing in cervical cancer screening.

METHODS

A total of 443 women were recruited from the Yuan's General Hospital. Cervical scrapings were collected for Papanicolaou (Pap) test by using cervical brushes, and the cytological data were used for analysis. The residual cells on the brush were preserved in phosphate-buffered saline solution at 4°C until DNA extraction. Then, the extracted DNA were used for molecular tests, which included human papillomavirus typing and quantification of the methylation levels for PAX1, SOX1, and NKX6-1 genes. Subjects who had abnormal Pap test results underwent colposcopy or biopsy with subsequent conization or major surgery when biopsy results revealed CIN2+. The final diagnosis for this group was confirmed by colposcopy or pathological examination. The study was approved by the institutional review board of Yuan's General Hospital, and all the molecular tests were performed by ISO17025 certified laboratories.

RESULTS

The sensitivity of PAX1 and SOX1 was greater than 80%, and the specificity of PAX1 and NXK6-1 was greater than 80% for the detection of CIN3+ lesions. PAX1 detection alone had a sensitivity and specificity of 86% and 85%, respectively, whereas when used as a cotest with the Pap test, the sensitivity and specificity were 89% and 83%, respectively.

CONCLUSIONS

PAX1 showed great potential as a biomarker for cervical cancer screening. When incorporating PAX1 detection into current screening protocol, the efficacy of screening could be greatly improved. Moreover, unnecessary referral for colposcopy and biopsy could be reduced up to 60%. However, prospective population-based studies are necessary for further implementation of this screening program.

Colorectal cancer prevention in Europe: burden of disease and status of screening programs

Colorectal cancer is a major public health challenge worldwide. In Europe it is the first malignancy in terms of incidence and the second in terms of mortality in both genders. Despite evidence indicating that removal of premalignant and early-stage cancer lesion scan greatly reduce mortality, remarkable differences are still found among countries both in terms of organized screening programs and of the tests used. In 2003 the European Council recommended that priority be given to activation of organized cancer screening programs, and various states have been making significant efforts to adopt effective prevention programs with international quality standards and centralizing screening organization and result evaluation. After a 2008 European Union report on the state of screening program, activation highlighted that little more than 50% (12/22) of Member States had colorectal cancer screening programs, Screening programs have been adopted or earlier pilot projects have been extended nationwide. This paper examines the state of activation and the screening strategies of colorectal cancer screening programs in EU States as of July 2013.

Competition in Colon Cancer Screening? What Is the Role of Colonoscopy?

BACKGROUND

Colorectal cancer (CRC) is one of the leading causes of cancer-related death in the Western world. The incidence could be reduced if this cancer were to be diagnosed at an early stage of disease. A competition has started between the existing screening methods to be the most efficient in detecting premalignant conditions. This review illustrates the current state of screening techniques for CRC.

METHOD

Pubmed was searched for meta-analyses and prospective studies on screening for CRC, with an emphasis on colonography, computed tomographic colonography (CTC), magnetic resonance colonography (MRC), stool DNA testing, and colon capsule endoscopy, and critical appraisal of the research was done by the reviewers.

RESULTS

The imaging techniques (CTC and MRC) had similar detection rates for bigger lesions (≥10 mm) as colonoscopy. High-definition colonoscopy showed better efficiency with smaller lesions. The techniques developing around colonoscopy such as the retro-viewing colonoscope, the balloon colonoscope, or the 330-degree viewing colonoscope try to enhance efficacy by reducing the adenoma miss rate in right-sided, non-polypoid lesions. Colon capsule endoscopy and the stool detection systems are limited to identifying cancer but not necessarily adenomas.

CONCLUSION

Colonoscopy is the preferred CRC screening strategy and the undisputed gold standard in terms of efficacy.

Identification and evaluation of plasma microRNAs for early detection of colorectal cancer

Background

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers. Circulating microRNAs (miRNAs) have been suggested as potentially promising markers for early detection of CRC. We aimed to identify and evaluate a panel of miRNAs that might be suitable for CRC early detection.

Methods

MiRNAs were profiled by TaqMan MicroRNA Array and screened for differential expression in 5 pools of plasma samples of CRC patients (N = 50) and 5 pools of neoplasm-free controls (N = 50). Additional miRNAs were selected from a literature review. Identified candidates were evaluated in independent validation samples with respect to discrimination of CRC patients (N = 80) or advanced adenoma patients (N = 50) and neoplasm-free controls (N = 194). Diagnostic performance of the panel of miRNAs was assessed by multiple logistic regression, using bootstrap analysis to correct for over-optimism.

Results

Five miRNAs identified to be differentially expressed from TaqMan MicroRNA Array (miR-29a, -106b, -133a, -342-3p, -532-3p), and seven miRNAs reported to be differentially expressed in the literature (miR-18a, -20a, -21, -92a, -143, -145, -181b) were selected for validation. Nine of the twelve miRNAs (miR-18a, -20a, -21, -29a, -92a, -106b, -133a, -143, -145) were found to be differentially expressed in CRC patients and controls in the validation samples. The optimism-corrected area under the curve was 0.745 (95% confidence interval: 0.708–0.846). None of the selected miRNAs showed significant differential expression between advanced adenoma patients and neoplasm-free controls.

Conclusion

The identified panel of miRNAs could be of potential use in the development of a multi-marker blood based test for early detection of CRC. Impact: The study underscores the high potential of plasma miRNAs for the improvement of current offers of non-invasive CRC screening.

Correlations between cytoplasmic CSE1L in neoplastic colorectal glands and depth of tumor penetration and cancer stage

Background

Colorectal carcinomas spread easily to nearby tissues around the colon or rectum, and display strong potential for invasion and metastasis. CSE1L, the chromosome segregation 1-like protein, is implicated in cancer progression and is located in both the cytoplasm and nuclei of tumor cells. We investigated the prognostic significance of cytoplasmic vs. nuclear CSE1L expression in colorectal cancer.

Methods

The invasion- and metastasis-stimulating activities of CSE1L were studied by in vitro invasion and animal experiments. CSE1L expression in colorectal cancer was assayed by immunohistochemistry, with tissue microarray consisting of 128 surgically resected specimens; and scored using a semiquantitative method. The correlations between CSE1L expression and clinicopathological parameters were analyzed.

Results

CSE1L overexpression was associated with increased invasiveness and metastasis of cancer cells. Non-neoplastic colorectal glands showed minimal CSE1L staining, whereas most colorectal carcinomas (99.2%, 127/128) were significantly positive for CSE1L staining. Cytoplasmic CSE1L was associated with cancer stage (P=0.003) and depth of tumor penetration (P=0.007). Cytoplasmic CSE1L expression also correlated with lymph node metastasis of the disease in Cox regression analysis

Conclusions

CSE1L regulates the invasiveness and metastasis of cancer cells, and immunohistochemical analysis of cytoplasmic CSE1L in colorectal tumors may provide a useful aid to prognosis.

[Screening for colorectal cancer. Current evidence and novel developments]

CLINICAL ISSUE

Colorectal cancer is one of the leading causes of cancer-related morbidity and mortality. Screening has been demonstrated to reduce both the incidence and mortality of colorectal cancer. In addition to the large group with a normal risk level, two further risk groups need to be distinguished: increased family risk and hereditary colorectal cancer syndromes. STANDARD METHODS FOR SCREENING: The highest evidence for all screening tests has been demonstrated for guaiac-based fecal occult blood testing. Colonoscopy is a diagnostic and therapeutic tool and it serves as the reference standard for other tests in clinical studies.

INNOVATIONS

Fecal immunochemical tests have a higher sensitivity than guaiac-based tests. Several novel techniques are under development and could be adopted by screening programs in the future. Next to colonoscopy, computed tomography (CT) colonography and colon capsule endoscopy have the highest sensitivity for colorectal neoplasia. Molecular tests which are based on the detection of genetic and epigenetic changes of DNA released by the tumor into feces or blood have a high potential and could potentially replace occult blood tests in the future.

PRACTICAL RECOMMENDATIONS

Colonoscopy is the primary instrument for screening for colorectal neoplasia. Fecal occult blood testing should only be performed if colonoscopy is denied and CT colonography has not yet been approved for screening in Germany.

Discriminant function based on parameters of hyaluronic acid metabolism and nitric oxide to differentiate metastatic from non-metastatic colorectal cancer patients

Colorectal cancer (CRC) is one of the most common causes of cancer-related deaths worldwide. Because there is currently no useful serological marker for metastatic colorectal cancer, the search for simple biomarkers for colorectal cancer diagnosis and prognosis is needed. Hyaluronic acid level was determined by ELISA; in addition to its degrading enzymes, degradation products and nitric oxide were determined by standard techniques in 185 CRC patients with and without metastases. Statistical analyses were performed by logistic regression and receiver-operating characteristic (ROC) curves. The multivariate discriminate analysis (MDA) selects a function based on absolute values of six biochemical markers; score = [-0.62 (numerical constant) + hyaluronic acid (pg/l) × 0.002 + hyaluronidase (mg N-acetyl glucosamine/ml/18 h) × 0.009-β-glucuronidase (μmol/ml/min) × 0.07 + N-acetyl-β-D-glucosaminidase (μmol/ml/min) × 0.019-glucuronic acid (μg/dl) × 0.001 + nitric oxide (μmol/l) × 0.01]. The selected MDA function correctly classified 92% of the metastatic CRC patients at a discriminate cut-off score = 0.24 (i.e., less than 0.24 indicated patients with non-metastatic colon cancer, and greater than 0.24 indicated patients with metastatic colon cancer with high degrees of sensitivity (100%) and specificity (93%)). The positive predictive and negative predictive values were also high (81% and 85%, respectively). Colorectal cancer patients can be simply and efficiently classified into metastatic or non-metastatic using their MDA score.

Screening for colorectal cancer: established and emerging modalities

It has been estimated that >95% of cases of colorectal cancer (CRC) would benefit from curative surgery if diagnosis was made at an early or premalignant polyp stage of disease. Over the past 10 years, most developed nation states have implemented mass population screening programs, which are typically targeted at the older (at-risk) age group (>50-60 years old). Conventional screening largely relies on periodic patient-centric investigation, particularly involving colonoscopy and flexible sigmoidoscopy, or else on the fecal occult blood test. These methods are compromised by either low cost-effectiveness or limited diagnostic accuracy. Advances in the development of diagnostic molecular markers for CRC have yielded an expanding list of potential new screening modalities based on investigations of patient stool (for colonocyte DNA mutations, epigenetic changes or microRNA expression) or blood specimens (for plasma DNA mutations, epigenetic changes, heteroplasmic mitochondrial DNA mutations, leukocyte transcriptome profile, plasma microRNA expression or protein and autoantibody expression). In this Review, we present a critical evaluation of the performance data and relative merits of these various new potential methods. None of these molecular diagnostic methods have yet been evaluated beyond the proof-of-principle and pilot-scale study stage and it could be some years before they replace existing methods for population screening in CRC.

Analysis of post-operative changes in serum protein expression profiles from colorectal cancer patients by MALDI-TOF mass spectrometry: a pilot methodological study

BACKGROUND

Mass spectrometry-based protein expression profiling of blood sera can be used to discriminate colorectal cancer (CRC) patients from unaffected individuals. In a pilot methodological study, we have evaluated the changes in protein expression profiles of sera from CRC patients that occur following surgery to establish the potential of this approach for monitoring post-surgical response and possible early prediction of disease recurrence.

METHODS

In this initial pilot study, serum specimens from 11 cancer patients taken immediately prior to surgery and at approximately 6 weeks following surgery were analysed alongside 10 normal control sera by matrix-assisted laser desorption ionisation time of-flight-mass spectrometry (MALDI-TOF MS). Using a two-sided t-test the top 20 ranked protein peaks that discriminate normal from pre-operative sera were identified. These were used to classify post-operative sera by hierarchical clustering analysis (Spearman's Rank correlation) and, as an independent 'test' dataset, by k-nearest neighbour and weighted voting supervised learning algorithms.

RESULTS

Hierarchical cluster analysis classified post-operative sera from all six early Dukes' stage (A and B) patients as normal. The remaining five post-operative sera from more advanced Dukes' stages (C1 and C2) were classified as cancer. Analysis by supervised learning algorithms similarly grouped all advanced Dukes' stages as cancer, with four of the six post-operative sera from early Dukes' stages being classified as normal (P = 0.045; Fisher's exact test).

CONCLUSIONS

The results of this pilot methodological study illustrate the proof-of-concept of using protein expression profiling of post-surgical blood sera from individual patients to monitor disease course. Further validation on a larger patient cohort and using an independent post-operative sera dataset would be required to evaluate the potential clinical relevance of this approach. Prospective data, including follow-up on patient survival, could in the future, then be evaluated to inform decisions on individualised treatment modalities.

Serum cellular apoptosis susceptibility protein is a potential prognostic marker for metastatic colorectal cancer

Colorectal cancer has high rates of recurrence and metastasis. Many patients with similar histopathological features show significantly different clinical outcomes, and these differences are primarily related to metastases undetected by current diagnostic methods. There is no useful serological marker for metastatic disease. We investigated the cellular apoptosis susceptibility (CSE1L/CAS) protein in comparison with carcinoembryonic antigen (CEA) as a marker for metastatic colorectal cancer. Using serum from 103 patients with stage I, II, III, and IV disease, CSE1L was detected in 36.0% (9 of 25), 57.7% (15 of 26), 71.4% (30 of 42), and 88.9% (8 of 9) of patients, respectively; a pathological CEA level was found in 16.0% (4 of 25), 42.3% (11 of 26), 47.6% (20 of 42), and 77.8% (7 of 9) of patients, respectively; a combined CSE1L/CEA assay was detected in 48.0% (12 of 25), 65.4% (17 of 26), 88.1% (37 of 42), and 100% (9 of 9) of patients, respectively. Lymphatic metastasis is an important predictor of poor prognosis and crucial for determination of therapeutic strategy. Serum CSE1L was detected in 74.5% (38 of 51) of patients with lymph node metastasis, whereas a pathological CEA level was found in only 52.9% (27 of 51) of the same patients (P < 0.001); the combined CSE1L/CEA assay increased sensitivity to 90.2% (46 of 51). Animal experiments showed CSE1L reduction in B16-F10 melanoma cells correlated with decreased metastasis to the colorectal tract in C57BL/6 mice. These results indicate that assay of serum CSE1L may facilitate diagnosis of colorectal cancer lymphatic metastases; furthermore, CSE1L is a possible therapeutic target.

Measuring the combinatorial expression of solute transporters and metalloproteinases transcripts in colorectal cancer

Background

It was hypothesised that colorectal cancer (CRC) could be diagnosed in biopsies by measuring the combined expression of a small set of well known genes. Genes were chosen based on their role in either the breakdown of the extracellular matrix or with changes in cellular metabolism both of which are associated with CRC progression

Findings

Gene expression data derived from quantitative real-time PCR for the solute transporter carriers (SLCs) and the invasion-mediating matrix metalloproteinases (MMPs) were examined using a Linear Descriminant Analysis (LDA). The combination of MMP-7 and SLC5A8 was found to be the most predictive of CRC.

Conclusion

A combinatorial analysis technique is an effective method for both furthering our understanding on the molecular basis of some aspects of CRC, as well as for leveraging well defined cancer-related gene sets to identify cancer. In this instance, the combination of MMP-7 and SLC5A8 were optimal for identifying CRC.

Circulating methylated SEPT9 DNA in plasma is a biomarker for colorectal cancer

BACKGROUND

The presence of aberrantly methylated SEPT9 DNA in plasma is highly correlated with the occurrence of colorectal cancer. We report the development of a new SEPT9 biomarker assay and its validation in case-control studies. The development of such a minimally invasive blood-based test may help to reduce the current gap in screening coverage.

METHODS

A new SEPT9 DNA methylation assay was developed for plasma. The assay comprised plasma DNA extraction, bisulfite conversion of DNA, purification of bisulfite-converted DNA, quantification of converted DNA by real-time PCR, and measurement of SEPT9 methylation by real-time PCR. Performance of the SEPT9 assay was established in a study of 97 cases with verified colorectal cancer and 172 healthy controls as verified by colonoscopy. Performance based on predetermined algorithms was validated in an independent blinded study with 90 cases and 155 controls.

RESULTS

The SEPT9 assay workflow yielded 1.9 microg/L (CI 1.3-3.0) circulating plasma DNA following bisulfite conversion, a recovery of 45%-50% of genomic DNA, similar to yields in previous studies. The SEPT9 assay successfully identified 72% of cancers at a specificity of 93% in the training study and 68% of cancers at a specificity of 89% in the testing study.

CONCLUSIONS

Circulating methylated SEPT9 DNA, as measured in the new (m)SEPT9 assay, is a valuable biomarker for minimally invasive detection of colorectal cancer. The new assay is amenable to automation and standardized use in the clinical laboratory.