The case for population-based screening for colorectal cancer

Plasma Circulating mRNA Profile for the Non-Invasive Diagnosis of Colorectal Cancer Using NanoString Technologies

Colorectal cancer (CRC) is one of the most prevalent cancers and the second leading cause of cancer deaths in developed countries. Early CRC may have no symptoms and symptoms usually appear with more advanced diseases. Regular screening can identify people who are at increased risk of CRC in order to offer earlier treatment. A cost-effective non-invasive platform for the screening and monitoring of CRC patients allows early detection and appropriate treatment of the disease, and the timely application of adjuvant therapy after surgical operation is needed. In this study, a cohort of 71 plasma samples that include 48 colonoscopy- and histopathology-confirmed CRC patients with TNM stages I to IV were recruited between 2017 and 2019. Plasma mRNA profiling was performed in CRC patients using NanoString nCounter. Normalized data were analyzed using a Mann-Whitney U test to determine statistically significant differences between samples from CRC patients and healthy subjects. A multiple-group comparison of clinical phenotypes was performed using the Kruskal-Wallis H test for statistically significant differences between multiple groups. Among the 27 selected circulating mRNA markers, all of them were found to be overexpressed (gene expression fold change > 2) in the plasma of patients from two or more CRC stages. In conclusion, NanoString-based targeted plasma CRC-associated mRNAs circulating the marker panel that can significantly distinguish CRC patients from a healthy population were developed for the non-invasive diagnosis of CRC using peripheral blood samples.

Re-engineering of peptides with high binding affinity to develop an advanced electrochemical sensor for colon cancer diagnosis

Colorectal cancer (CRC) develops from polyps in the inner large intestine or rectum and an increasing incidence and high mortality rate has been observed in humans. Currently, colonoscopy is the preferred modality for early CRC diagnosis. However, this technique has several limitations, such as high medical costs and intricate procedures, leading to increasing demands for the development of a new, simple, and affordable diagnostic method. In this study, an advanced electrochemical biosensor based on rationally designed affinity peptides was developed for discriminating adenoma to carcinoma progression. Amino acid-substituted and rationally designed synthetic peptides (BP3-1 to BP3-8) based on in silico modeling studies were chemically synthesized, and covalently immobilized onto a gold electrode using aromatic ring compounds through surface chemistry techniques. The binding performance of the developed sensor system was observed using square wave voltammetry (SWV). The peptide BP3-2 was selected depending on its relative binding affinity; SWV indicated the limit of detection of BP3-2 for LRG1 to be 0.025 μg/mL. This sensor could distinguish the adenoma-carcinoma transition with improved binding abilities (specificity and selectivity), and stability in plasma samples spiked with LRG1 and real samples from patients with CRC. These results indicate that this electrochemical sensor system can be used for early monitoring of the colorectal adenoma to carcinoma progression.

Can Vascular Endothelial Growth Factors and CD34 Expression Implement NICE (Narrow-Band Imaging International Colorectal Endoscopic) Classification in Colorectal Polypoid Lesion Diagnosis?

BACKGROUND

Vascular endothelial growth factor (VEGF) is a subfamily of growth factors involved in angiogenesis; CD34+ cells are normally found in endothelial progenitor cells and endothelial cells of blood vessels. Colonic adenomatous polyps may not always be completely removable endoscopically, and a preoperative diagnosis might still be necessary. The aim of the study was to evaluate whether VEGF-A, VEGF-C and CD34 mRNA expression along colorectal carcinogenesis steps can implement NICE (Narrow-Band Imaging International Colorectal Endoscopic) classification in the diagnosis of malignancy in colorectal polypoid lesions.

METHODS

Seventy-one subjects with colonic adenoma or cancer who underwent screening narrow-band imaging (NBI) colonoscopy were prospectively enrolled in the MICCE1 project (Treviso center). Polyps were classified according to the NICE classification. Real-time RT-PCR for VEGF-A, VEGF-C and CD34 mRNA expression was performed. Nonparametric statistics, receiver-operating characteristic curve analysis and logistic multiple regression analysis were used.

RESULTS

VEGF-A and CD34 mRNA expression was significantly higher in sessile adenomas than in polypoid ones (p < 0.001 and p = 0.01, respectively). VEGF-A, VEGF-C and CD34 mRNA expression was significantly higher in adenocarcinoma than in adenoma (p = 0.01, p = 0.01 and p = 0.01, respectively). The accuracy of VEGF-A, VEGF-C and CD34 mRNA expression for prediction of malignancy was 0.79 (95% CI 0.65-0.90), 0.81 (95% CI 0.66-0.91) and 0.80 (95% CI 0.65-0.90), respectively, while the accuracy of the NICE classification was 0.85 (95% CI 0.72-0.94). The determination coefficient R2, which indicates the amount of the variability explained by a regression model, for NICE classification alone was 0.24 (p < 0.001). A regression model that included NICE classification and VEGF-C mRNA expression showed an R2 = 0.39 as well as a model including NICE classification and CD34 mRNA levels.

CONCLUSIONS

This study demonstrated that VEGF-C and CD34 mRNA levels might be useful to stratify colorectal polyps in different risk of progression classes by implementing the accuracy of the NICE classification. Studies on in vivo detection of these markers are warranted.

Hotspot KRAS exon 2 mutations in CD166 positive colorectal cancer and colorectal adenoma cells

Colorectal cancer (CRC) is the third most common cancer and the fourth leading cause of cancer deaths worldwide. Recent studies have shown that cancer stem cells (CSCs) are an important cause of tumor recurrence and metastasis. We hypothesized that CSCs marker CD166-positive CRC and colorectal adenoma (CAD) cells consist of more hotspot mutations than CD166-negative CRC and colorectal adenoma cells. To verify this, formalin fixed paraffin embedded tissue specimens from 42 patients each with CRC and CAD were recruited and CD166 immunohistochemical (IHC) staining followed by macrodissection was performed. DNA extracted was used for quantitative polymerase chain reaction detection on a somatic mutation array. Results showed that the immunoreactivity of CD166 protein had significant difference among CRC, CAD, and normal colorectal epithelial tissues (NCET) (P < 0.0001, Kruskal-Wallis test). Moreover, nucleotide changes were found in APC, KRAS, P53, PIK3CA, FBXW7 and SRC genes. Among those genes, KRAS exon 2 mutations were validated in another cohort of 70 CRC and 72 CAD specimens. Results showed that the difference in percentage of KRAS exon 2 mutations between CD166 positive and CD166 negative CRC specimens was significant (P < 0.05, chi-square test). Long term follow-up of the CRC patients showed that CD166-positive KRAS exon 2 mutations was useful in discriminating CRC patients with worse outcome. This study has provided evidence that KRAS exon 2 mutations are concentrated in CD166-positive cancer cells, with prognostic significance in CRC, and those mutations are also detected in CAD.

Colorectal polypoid lesions and expression of vascular endothelial growth factor in a consecutive series of endoscopic and surgical patients

Colorectal cancer incidence in patients undergoing screening protocols is decreasing because of the higher rate of discovered preneoplastic colonic lesions; however, adenomatous polyps may not always be removable endoscopically and surgery may still be necessary. The aim of this study was to assess the vascular endothelial growth factor expression in the different steps of colorectal carcinogenesis to explore its potential role as a marker of malignancy in polypoid lesions. A total of 92 subjects with colonic adenoma or cancer who underwent screening colonoscopy or surgery were prospectively enrolled. Real-time reverse transcription polymerase chain reaction for VEGF-A messenger RNA expression and immunohistochemistry for VEGF-A were performed. Immunoassays for VEGF-A, VEGF-C, VEGFR-1, VEGFR-2, and VEGFR-3 were also performed. Non-parametric statistics, receiver operating characteristic curve analysis, and logistic multiple regression analysis were used. VEGF-A messenger RNA expression was higher in patients with high-grade dysplasia or colorectal cancer than in those with low-grade dysplasia adenomas (p = 0.01). At immunohistochemistry, VEGF-A expression was significantly higher in colorectal cancer patients compared to dysplastic adenomas (p < 0.001), and the accuracy of VEGF-A expression for prediction of malignancy was 91.7 (95% confidence interval = 78.7-97.9). VEGF-C protein expression was lower in colorectal cancer patients than in simple adenomas (p = 0.02). VEGF-A levels were directly correlated to polyp size (rho = 0.73, p = 0.0062). Multivariate analysis demonstrated that malignancy and polyp size were independent predictors of VEGF-A mucosal levels. This study demonstrated that the VEGF-A expression changes along the colorectal carcinogenesis pathway showing a neat step up at the passage from high-grade dysplasia to invasive cancer. This feature might potentially be useful to stratify colorectal polyps in different risks of progression classes. Moreover, the high level of VEGF-A expression predicted the presence of lymphovascular invasion with good accuracy.

Peptide-Based Treatment: A Promising Cancer Therapy

Many new therapies are currently being used to treat cancer. Among these new methods, chemotherapy based on peptides has been of great interest due to the unique advantages of peptides, such as a low molecular weight, the ability to specifically target tumor cells, and low toxicity in normal tissues. In treating cancer, peptide-based chemotherapy can be mainly divided into three types, peptide-alone therapy, peptide vaccines, and peptide-conjugated nanomaterials. Peptide-alone therapy may specifically enhance the immune system's response to kill tumor cells. Peptide-based vaccines have been used in advanced cancers to improve patients' overall survival. Additionally, the combination of peptides with nanomaterials expands the therapeutic ability of peptides to treat cancer by enhancing drug delivery and sensitivity. In this review, we mainly focus on the new advances in the application of peptides in treating cancer in recent years, including diagnosis, treatment, and prognosis.

Flavonoids and Wnt/β-catenin signaling: potential role in colorectal cancer therapies

It is now well documented that natural products have played an important role in anticancer therapy. Many studies focus on the ability of these natural compounds to modulate tumor-related signaling pathways and the relationship of these properties to an anticancer effect. According to the World Health Organization (WHO), colorectal cancer (CRC) is the third most common cancer and the fourth leading cause of cancer death among men and women. Therefore, finding strategies to fight against CRC is an emergent health problem. CRC has a strong association with deregulation of Wnt/β-catenin signaling pathway. As some types of natural compounds are capable of modulating the Wnt/β-catenin signaling, one important question is whether they could counteract CRC. In this review, we discuss the role of flavonoids, a class of natural compounds, on Wnt/β-catenin regulation and its possible potential for therapeutic usage on colorectal cancer.

Proteomic analysis of colorectal cancer: discovering novel biomarkers

Colorectal cancer is one of the most common cancers in the Western world. When detected at an early stage, the majority of cancers can be cured with current treatment modalities. However, most cancers present at an intermediate stage. The discovery of sensitive and specific biomarkers has the potential to improve preclinical diagnosis of primary and recurrent colorectal cancer, and holds the promise of prognostic and therapeutic application. Current biomarkers such as carcinoembryonic antigen lack sensitivity and specificity for general population screening. This review aims to highlight the role of current proteomic technologies in the discovery and validation of potential biomarkers with a view to translation to the clinic.

Clinical significance of frizzled homolog 3 protein in colorectal cancer patients

Frizzled homolog 3 receptor was up-regulated in several gastrointestinal cancers such as esophageal and gastric cancers. Moreover, frizzled homolog 3 has recently reported to be expressed in colorectal adenoma specimens. In the present study, we investigated the clinical significance of frizzled homolog 3 protein in colorectal cancer patients. Using immunocytochemical staining, frizzled homolog 3 expression was examined in 186 colorectal cancer specimens, 79 colorectal adenoma specimens, 133 colorectal polyp specimens, 127 colorectal cancer specimens with lymph node and/or distant metastasis, 310 specimens of various non-colorectal cancer metastatic carcinomas and 40 specimens with simultaneous occurrence of colorectal cancer, colorectal adenoma and colorectal polyp. Statistical analysis was used to correlate frizzled homolog 3 protein expression to the clinicohistopathological factors, recurrence/metastasis and survival after follow-up for 42 months in colorectal cancer patients. Frizzled homolog 3 protein was expressed in 100% colorectal cancer specimens, 89% colorectal adenoma specimens, 75% colorectal polyp specimens and 69% normal colorectal epithelial tissues. Moreover, frizzled homolog 3 immunocytochemical scores were highly correlated with colorectal cancer progression. Furthermore, frizzled homolog 3 was expressed in a comparatively lower percentage of metastatic hepatocellular carcinoma and metastatic renal clear cell carcinoma with focal and very weak staining than other metastatic tumor types. On the other hand, the frizzled homolog 3 immunocytochemical scores of colorectal adenomas with synchronous colorectal carcinomas were significantly higher than those of pure colorectal adenomas. Statistical analysis showed that frizzled homolog 3 immunocytochemical scores were associated with Dukes stage and lymph node status. Finally, stratified groups of colorectal cancer patients had significant differences in their recurrence/metastasis and survival. In conclusion, the present large-scale study has clearly showed that frizzled homolog 3 protein can generate clinically important information for colorectal cancer patients.

Candidate biomarker verification: Critical examination of a serum protein pattern for human colorectal cancer

PURPOSE

We critically examine a candidate serum protein pattern for human colorectal cancer (CRC) with respect to reproducibility, sample handling, and disease specificity.

EXPERIMENTAL DESIGN

Serum samples from CRC patients, patients with benign colon tumors and healthy individuals, were obtained at two collection sites and analyzed by SELDI-TOF MS on 8 days, over a period of 5 weeks. The spectra were subjected to multivariate analysis. Tissues from normal colon and CRC were analyzed by SELDI-TOF MS. Selected mass peaks were identified.

RESULTS

Using an elaborate experimental design we developed a multivariate classifier that correctly classified CRC and control serum measured on an independent day. The classifier did not discriminate between samples from CRC patients and patients with benign colon tumors, and, secondly, did not correctly classify serum from an independent collection site. All discriminatory mass peaks were identified as high abundant plasma proteins. Tissue profiling provided support of increased proteolytic activity in CRC tissue.

CONCLUSION AND CLINICAL RELEVANCE

Critical verification did not justify advancing the identified CRC serum protein pattern into clinical validation without improvement. We believe that proteomics biomarker research could benefit if the presented, or a similar, verification scheme was more commonly employed in explorative biomarker studies.

EPAS1 mRNA in plasma from colorectal cancer patients is associated with poor outcome in advanced stages

The presence of free nucleic acids in plasma has been detected in cancer patients and is associated with poor prognosis. In the present study, the mRNA levels of three genes (EPAS1, KIAA0101 and UBE2D3) in plasma from colorectal cancer patients were analyzed. These genes were selected from a previous study of genomic profiles, discriminating between healthy controls and colorectal cancer patients. mRNA levels were analyzed by real-time PCR in the plasma of 154 patients with colorectal cancer. The association of plasma mRNA levels with clinicopathological parameters and patient survival were analyzed. High levels of EPAS1 in the plasma were associated with patients aged over 50 years, relapse of disease and patient mortality. When patients were divided into two groups, early (I and II) and advanced (III and IV) stages, an association was observed between high levels of EPAS1 mRNA and worse disease-free and overall survival in advanced stages. The expression of KIAA0101 and UBE2D3 was not associated with poor prognosis. Thus, our results suggest that EPAS1 mRNA levels may be an indicator of poor prognosis in colorectal cancer patients at advanced stages, obtained by a non-invasive method.

Emerging adenosine receptor agonists

Adenosine receptors (ARs) are a four-member subfamily of G protein-coupled receptors and are major targets of caffeine and theophylline. There are four subtypes of ARs, designated as A1, A2A, A2B and A3. Selective agonists are now available for all four subtypes. Over a dozen of these selective agonists are now in clinical trials for various conditions, although none has received regulatory approval except for the endogenous AR agonist adenosine itself. A1AR agonists are in clinical trials for cardiac arrhythmias and neuropathic pain. A2AAR agonists are now in trials for myocardial perfusion imaging and as anti-inflammatory agents. A2BAR agonists are under preclinical scrutiny for potential treatment of cardiac ischemia. A3AR agonists are in clinical trials for the treatment of rheumatoid arthritis and colorectal cancer. The present review will mainly cover the agonists that are presently in clinical trials for various conditions and only a brief introduction will be given to major chemical classes of AR agonists presently under investigation.

Referring patients to nurses: outcomes and evaluation of a nurse flexible sigmoidoscopy training program for colorectal cancer screening

Colorectal cancer is a significant health burden. Several screening options exist that can detect colorectal cancer at an early stage, leading to a more favourable prognosis. However, despite years of knowledge on best practice, screening rates are still very low in Canada, particularly in Ontario. The present paper reports on efforts to increase the flexible sigmoidoscopy screening capacity in Ontario by training nurses to perform this traditionally physician-performed procedure. Drawing on American, British and local experience, a professional regulatory framework was established, and training curriculum and assessment criteria were developed. Training was initiated at Princess Margaret Hospital and Sunnybrook and Women's College Health Sciences Centre in Toronto, Ontario. (During the study, Sunnybrook and Women's College Health Sciences Centre was deamalgamated into two separate hospitals: Women's College Hospital and Sunnybrook Health Sciences Centre.) Six registered nurses participated in didactic, simulator and practical training. These nurses performed a total of 77 procedures in patients, 23 of whom had polyps detected and biopsied. Eight patients were advised to undergo colonoscopy because they had one or more neoplastic polyps. To date, six of these eight patients have undergone colonoscopy, one patient has moved out of the province and another patient is awaiting the procedure. Classifying the six patients according to the most advanced polyp histology, one patient had a negative colonoscopy (no polyps found), one patient's polyps were hyperplastic, one had a tubular adenoma, two had advanced neoplasia (tubulovillous adenomas) and one had adenocarcinoma. All these lesions were excised completely at colonoscopy. Overall, many difficulties were anticipated and addressed in the development of the training program; ultimately, the project was affected most directly by challenges in encouraging family physicians to refer patients to the program. As health human resource strategies continue to evolve, it is believed that lessons learned from experience make an important contribution to the knowledge of how nontraditional health services can be organized and delivered.

Human neutrophil peptides 1, 2 and 3 are biochemical markers for metastatic colorectal cancer

Colorectal cancer (CRC) patients have increased levels of human neutrophil peptides 1-3 (HNP1-3) in tumour tissue and plasma. The aim is to study whether the amount of HNP1-3 in tumour and plasma from CRC patients correlate with Dukes' stages A-D. The amount of HNP1-3 in tumour tissue, normal colonic mucosa, and plasma was determined with mass spectrometry. Plasma levels of HNP1-3 were determined with enzyme-linked immuno-sorbent assay (ELISA). The amount of HNP1-3 determined with mass spectrometry was increased in tumours compared to normal colonic tissue in CRC patients in Dukes' stage A-D, whereas HNP1-3 in plasma was only elevated in Dukes' stage D compared to healthy individuals. HNP1-3 plasma concentration determined with ELISA was increased in Dukes' stages C and D, but not in A and B. It is concluded that HNP1-3 is a potential marker for prognostic assessment, surveillance of patients, and monitoring chemotherapy in CRC patients with advanced disease.

Thymidylate synthase messenger RNA expression in plasma from patients with colon cancer: prognostic potential

PURPOSE

Thymidylate synthase (TS), a critical target in fluorouracil-based chemotherapy, is a prognostic marker in colon carcinomas and a predictor of response to treatment. Tumor RNA has been detected in plasma from cancer patients and is associated with poor prognosis. This is the first study to examine extracellular TS mRNA in plasma from patients with colon carcinoma, and its possible relation with TS promoter enhancer region (TSER) polymorphism.

EXPERIMENTAL DESIGN

TS expression was measured in plasma from 88 patients and 26 controls, and in a tumor subgroup of this series by quantitative PCR. Genotyping for TSER polymorphism was done in 60 patients. Clinicopathologic variables were correlated with these molecular changes.

RESULTS

TS mRNA was detected in plasma in 47% of patients, showing significant differences from healthy controls. Patients with TS mRNA in plasma had higher levels of TS in tumor tissue than patients without. The presence of TS mRNA was associated with lymph node metastases and more advanced stages. Polymorphism TSER 3/3 was found in 38% of cases, and was significantly correlated with high amounts of TS mRNA in plasma.

CONCLUSIONS

Our results suggest that TS mRNA in plasma originated from tumors, it may indicate poor prognosis and might help to classify tumors in Dukes' stages B and C. The TSER genotype may influence TS mRNA expression in plasma.

Microsatellite instability in colorectal cancer

BACKGROUND

Microsatellite instability (MSI) causes hereditary non-polyposis colorectal cancer (HNPCC), and occurs in about 15 per cent of sporadic colorectal cancers. Although the basic mechanisms are not clear, there is increased understanding of the clinicopathological consequences of MSI.

METHODS

Medline was searched for articles with a combination of keywords relating to MSI in colorectal cancer, focusing on molecular mechanisms, clinicopathological implications, and prognostic and predictive value. Emphasis was placed on articles from the past 5 years.

RESULTS

The genetic mechanisms differ in hereditary (germline mutation) and sporadic (epigenetic silencing) colorectal cancer. The MSI pathway frequently has altered transforming growth factor beta receptor II and BAX genes, often beta-catenin, and occasionally p16INK4A and PTEN. Changes in K-ras, adenomatous polyposis coli and p53 are rare. Polymerase chain reaction testing for MSI is superior to immunohistochemistry, but complicated by the number and types of nucleotide markers. The Bethesda panel guides HNPCC testing, but guidelines are lacking for general screening. The presence and role of low-frequency MSI remains controversial. Tumours with MSI tend to occur in the proximal colon and be large, but they have a good prognosis. Their reduced response to adjuvant chemotherapy requires confirmation.

CONCLUSION

Research on colorectal cancer needs to be stratified according to microsatellite status in order further to explore the molecular mechanisms and clinicopathological consequences of MSI.

Understanding non-compliance to colorectal cancer screening: a case control study, nested in a randomised trial [ISRCTN83029072]

Background

The major limit to colorectal cancer screening effectiveness is often low compliance. We studied the reasons for non compliance and determinants of compliance to faecal occult blood tests in Lazio, Italy.

Methods

This is a case-control study nested within a trial that tested the effect of type of test and provider on colorectal cancer screening compliance. Non compliant trial subjects were classified as cases, and compliant subjects were classified as controls. We sampled 600 cases and 600 controls matched by their general practitioner, half were invited for screening at the hospital, and the other half directly at their general practitioner's office. Cases and controls answered questions on: distance from test provider, logistical problems, perception of colorectal cancer risk, confidence in screening efficacy, fear of results, presence of colorectal cancer in the family, and gastrointestinal symptoms.

Results

About 31% of cases never received the letter offering free screening, and 17% of the sampled population had already been screened. The first reported reason for non-compliance was "lack of time" (30%); the major determinant of compliance was the distance from the test provider: odds ratio >30 minutes vs <15 minutes 0.3 (95%CI = 0.2–0.7). The odds ratio for lack of time was 0.16 (95% IC 0.1–0.26). The effect was stronger if the hospital (0.03 95%CI = 0.01–0.1) rather than the general practitioner (0.3 95%CI = 0.2–0.6) was the provider. Twenty-two percent of controls were accompanied by someone to the test.

Conclusion

To increase compliance, screening programmes must involve test providers who are geographically close to the target population.

The genetic factors in cancer development and their implications for cancer prevention and detection

Experimental data from laboratory animals indicate that the same extent of DNA damage or the same mutations in oncogenes and tumor suppressor genes in different hosts result in widely differing cancer development because of numerous polymorphic tumor susceptibility genes. Similarly, recent epidemiological data indicate that susceptibility to common, "sporadic" cancers in humans is influenced considerably by multiple polymorphic host genes with relatively weak effects. This indicates that in addition to hereditary familial cancer syndromes, the sporadic cancer is also under strong genetic control. The multiplicity of genes involved, variation in exposure to environmental carcinogens, and small sizes of cancer families prevent efficient searches for the responsible genes in humans. Therefore, an alternative strategy based on the definition of susceptibility genes in experimental animals and the subsequent study of their human homologues has been successfully employed by several groups. This strategy also helped reveal several important features of cancer susceptibility, including mutual interactions of cancer susceptibility genes, their functional heterogeneity, and the existence of stage-specific control of cancer development. This latter phenomenon is especially important, because the susceptibility to early stages of cancer development may be quite different from that of late stages of cancer development. This needs to be taken into account when introducing preventive testing of biomarkers of early preneoplastic lesions or early cancers, because their predictive value is greatly influenced by the genetically determined individual tendency to proceed toward a more advanced form of neoplasia. Therefore, genetic testing of persons in danger of being exposed to carcinogenic factors should be an important part of the personnel selection.

Modulatory effects of quercetin on proliferation and differentiation of the human colorectal cell line Caco-2

The effect of the dietary flavonoid quercetin was investigated on proliferation and differentiation of the human colon cancer cell line Caco-2. Confluent Caco-2 monolayers exposed to quercetin showed a biphasic effect on cell proliferation and a decrease in cell differentiation (0.001<P<0.05). During differentiation Caco-2 cells formed 5 phase II metabolites, of which the amount of 4'-O-methyl-quercetin-3'-O-glucuronide correlated with the differentiation grade (r=0.99, P<0.003). The increment of cell proliferation at low quercetin concentrations and the decrease in cell differentiation are effects opposite to what would be expected for a functional food ingredient with anti-carcinogenic potential.

Colon cancer secreted protein-2 (CCSP-2), a novel candidate serological marker of colon neoplasia

Cancers of the colon and rectum are the second leading cause of cancer death among adult Americans. When detected at early stages, colon cancer is highly curable. Colonoscopy, an effective but invasive screening test, has been limited in its public acceptance. The goal of this study was to identify novel serum markers of colon cancers and precancerous colon adenomas as potential candidates for noninvasive detection of early colon neoplasms. Employing expression microarrays, we identified colon cancer secreted protein-2 (CCSP-2) as a novel transcript whose expression is generally absent in normal colon and other normal body tissues, but that is induced an average of 78-fold in Stage II, III, and IV colon cancers, as well as in colon adenomas and colon cancer cell lines. These findings were validated by real-time PCR analysis in an independent panel of colon cancer cases. Moreover, CCSP-2 was shown to encode a secreted protein that circulates stably and is detectable in the blood of mice bearing human cancer xenografts transfected with epitope-tagged CCSP-2. As a novel secreted protein that is markedly induced in colon adenomas and cancers, CCSP-2 is a novel candidate for development as a diagnostic serum marker of early stage colon cancer.

Upregulated expression of human neutrophil peptides 1, 2 and 3 (HNP 1-3) in colon cancer serum and tumours: a biomarker study

Background

Molecular markers for localized colon tumours and for prognosis following therapy are needed. Proteomics research is currently producing numerous biomarker studies with clinical potential. We investigate the protein composition of plasma and of tumour extracts with the aim of identifying biomarkers for colon cancer.

Methods

By Surface Enhanced Laser Desorption/Ionisation – Time Of Flight / Mass spectrometry (SELDI-TOF/MS) we compare the protein profiles of colon cancer serum with serum from healthy individuals and the protein profiles of colon tumours with normal colon tissue. By size exclusion chromatography, we investigate the binding of HNP 1-3 to high mass plasma proteins. By microflow we investigate the effect of HNP 1-3 on mammalian cells.

Results

Human Neutrophil Peptides -1, -2 and -3 (HNP 1-3), also known as alfa-defensin-1, -2 and -3, are present in elevated concentrations in serum from colon cancer patients and in protein extracts from colon tumours. A fraction of HNP 1-3 in serum is bound to unidentified high mass plasma proteins. HNP 1-3 purified from colon tumours are lethal to mammalian cells.

Conclusions

HNP 1-3 may serve as blood markers for colon cancer in combination with other diagnostic tools. We propose that HNP 1-3 are carried into the bloodstream by attaching to high mass plasma proteins in the tumour microenvironment. We discuss the effect of HNP 1-3 on tumour progression.

Quantification of plasma beta-catenin mRNA in colorectal cancer and adenoma patients

PURPOSE

Colorectal cancer is an important cause of cancer deaths. Here, we focused our investigation on the beta-catenin gene which is implicated in colorectal carcinogenesis and tested whether beta-catenin mRNA is detectable in the plasma of colorectal carcinoma and adenoma patients using quantitative reverse transcriptase-PCR.

EXPERIMENTAL DESIGN

Plasma beta-catenin mRNA was measured from 58 colorectal carcinoma patients, 49 colorectal adenoma patients, and 43 apparently normal subjects using intron-spanning primers and Taqman probes. Five clinicopathological parameters were studied and correlated with plasma beta-catenin mRNA concentration. Additionally, 19 colorectal carcinoma patients after tumor removal were also recruited for plasma beta-catenin mRNA measurement to further demonstrate the clinical usefulness of this test.

RESULTS

beta-catenin mRNA was detected with median concentrations of 8737 (range: 1480-933100), 1218 (range: 541-2254) and 291 (range: 0-1366) copies/ml plasma in colorectal carcinoma, colorectal adenoma, and apparently normal subjects, respectively. Statistical analysis demonstrated that plasma beta-catenin mRNA concentration was correlated to tumor stage but not sex, age, lymph node status, and degree in differentiation. Moreover, plasma beta-catenin mRNA concentration decreased significantly after tumor removal in 16 of 19 (84%) colorectal carcinoma patients.

CONCLUSIONS

We conclude that plasma beta-catenin mRNA may potentially serve as a marker for colorectal cancer.

Detection of colorectal polyps by multislice CT colonography with ultra-low-dose technique: comparison with high-resolution videocolonoscopy

BACKGROUND

This prospective study compared multislice CT colonography with ultra-low-dose technique to high-resolution videocolonoscopy as the standard for detection of colorectal cancer and polyps.

METHODS

After standard bowel preparation, 115 patients underwent multislice CT colonography with an ultra-low-dose multislice CT colonography protocol immediately before videocolonoscopy. After noise reduction by using a mathematical algorithm, ultra-low-dose multislice CT colonographic images were analyzed in blinded fashion, and the results were compared with the results of high-resolution videocolonoscopy.

RESULTS

A total of 150 lesions were detected by high-resolution videocolonoscopy in 115 patients. For ultra-low-dose multislice CT colonography, sensitivities for detection of polyps less than 5 mm in size, 5 to 10 mm, and greater than 10 mm in diameter were 76%, 91%, and 100%, respectively. Although the sensitivity for detection of flat lesions was only 50%, the sensitivity and the specificity for detection of polyps 5 mm or greater in size were 94% and 84%, respectively. For adenomatous lesions greater than 5 mm in size, sensitivity was 94% and specificity was 92%. The overall specificity was 79%. The calculated effective radiation dose ranged between 0.75 and 1.25 mSv.

CONCLUSIONS

Compared with high-resolution videocolonoscopy, ultra-low-dose multislice CT colonography has excellent sensitivity and specificity for detection of colorectal lesions 5 mm or greater in size, and the radiation exposure is relatively low. However, before this technique can be generally recommended for colorectal screening, further improvement in the detection of flat and extremely small lesions must be achieved.

Evidence-based health policy: context and utilisation

Evidence-based decision-making is centred on the justification of decisions. In the shift from an individual-clinical to a population-policy level, the decision-making context becomes more uncertain, variable and complex. To address this we have developed a conceptual framework for evidence-based decision-making, focusing on how context impacts on what constitutes evidence and how that evidence is utilised. We present two distinct orientations towards what constitutes evidence, representing different relationships between evidence and context. We also categorise the decision-making context based on the ways in which context impacts on evidence-based decision-making. Furthermore, we invoke the concept of axes of evidence-based decision-making to describe the relationship between evidence and context as we move from evidence-based medicine to evidence-based health policy. From this, we suggest that it may be more important how evidence is utilised than how it is defined. Based on the research and knowledge utilisation literature, we present a process model of evidence utilisation, which forms the basis for the conceptual framework for context-based evidence-based decision-making. The conceptual framework attempts to capture the role that context plays in the introduction, interpretation and application of evidence. We illustrate this framework with examples from policy development for colorectal cancer screening.