Advances in Fecal Tests for Colorectal Cancer Screening. ACTA ACUST UNITED AC. 2016;14:152-162. [PMID: 26825703 PMCID: PMC4783443 DOI: 10.1007/s11938-016-0076-0]

Aberrant protein glycosylation in the colon adenoma-cancer sequence: Colorectal cancer mechanisms and clinical implications

Colorectal cancer (CRC) is a leading contributor to global cancer-related morbidity and mortality. Glycosylation is a common post-translational protein modification. Aberrant protein glycosylation is a hallmark of cancer, affecting biological processes and driving malignant CRC phenotypes. Specifically, abnormal N-glycosylation manifests as structural alterations in high mannose, sialylated, and fucosylated structures, collectively promoting cancer stemness and invasiveness. Concurrently, O-GlcNAcylation facilitates tumorigenesis through metabolic reprogramming and oncogene activation. Dysregulated mucin-type O-glycans (e.g., Core-1/Core-3 imbalance) and elevated SLex/SLea antigen expression are significantly correlated with tumor adhesion, metastatic dissemination, and adverse clinical outcomes. Furthermore, protein glycosylation contributes to chemoresistance through anti-apoptotic mechanisms, aberrant signaling activation, and pro-angiogenic pathways. This review systematically examines the dynamic evolution of protein glycosylation during CRC progression from normal mucosa to adenoma to adenocarcinoma. It also evaluates the CRC diagnostic and therapeutic implications of glycoproteins and glycans. This review can provide a molecular understanding for advancing CRC diagnostics and treatment.

Evaluating the implementation of colorectal cancer screening practices at King Abdul-Aziz Medical City, Riyadh

Background

Colorectal cancer (CRC) is a major public health problem in Saudi Arabia, where there is currently no widespread CRC screening program. This study aimed to assess the implementation of CRC screening within medical practices at King Abdul-Aziz Medical City in Riyadh, Saudi Arabia, targeting beneficiaries aged 50-75 years.

Methodology

A retrospective chart review and cross-sectional analysis were conducted between January and December 2022 for an age group from 50 to 75 years. Frequency and percentages were used to display categorical variables. The Chi-square test and independent t-test were used to assess the association between the variables.

Results

Out of the 296 patients between the ages of 50 and 75 years, less than half were men (49%). The average age of the participants was 61.5 years, ranging from 56 to 69. During the research, the incidence of CRC among patients was found to be 8.1%. Most patients had negative FOBT tests (73%), while about 27% tested positive, and approximately 23% underwent colonoscopy. Patients with a FOBT test positive tended to be older than those with a negative result.

Conclusion

This study found that the utilization of CRC screening is not fully maximized at King Abdul-Aziz Medical City. It highlights the importance of raising awareness and promoting adherence to screening guidelines for individuals between the ages of 50 and 75 years. Additional research is necessary to identify the factors that hinder or facilitate CRC screening in this context to assess the effectiveness and cost-effectiveness of various screening methods.

Global prevalence of Fusobacterium nucleatum and Bacteroides fragilis in patients with colorectal cancer: an overview of case reports/case series and meta-analysis of prevalence studies

BACKGROUND

Colorectal cancer (CRC) is the second deadliest carcinoma across the globe and has been known as a multi-factor induced-disease. Emerging research have demonstrated that bacterial colonization may contribute to the initiation and promotion of the CRC. The presence of Fusobacterium nucleatum (F. nucleatum) and Bacteroides fragilis (B. fragilis) in the gut is associated with the development of CRC. In this study, the prevalence of F. nucleatum and B. fragilis among CRC patients has been assessed worldwide through a systematic review and meta-analysis.

METHODS

The extensive search was performed using "Fusobacterium nucleatum", "Bacteroides fragilis", "Colorectal cancer" and all relevant keywords. Then, a systematic paper screening was done following a comprehensive search in Embase, Web of Science, and PubMed databases while the time range was limited between the years 2000 and 2024. Afterwards, statistical analysis was performed utilizing the comprehensive meta-analysis (CMA) software (version 2.0, Biostat, USA).

RESULTS

According to the meta-analysis of prevalence studies, the prevalence of F. nucleatum among 19 countries and B. fragilis among 10 countries were indicated to be 38.9% (95% CI 33.7-44.3%) and 42.5% (95% CI 34.4-51.1%), respectively, among the CRC patients. It was then revealed that Asia had the highest prevalence of F. nucleatum while most of the B. fragilis isolates in CRC cases were reported in European countries. Moreover, the data suggested that the most common comorbidity observed among the CRC cases was diabetes.

CONCLUSION

Our results emphasized the high prevalence of F. nucleatum and B. fragilis in CRC patients. Based on this meta-analysis review, regulating the gut microbiota in CRC patients seemed to be a promising approach to improving the efficacy of CRC therapy.

Microbiome confounders and quantitative profiling challenge predicted microbial targets in colorectal cancer development

Despite substantial progress in cancer microbiome research, recognized confounders and advances in absolute microbiome quantification remain underused; this raises concerns regarding potential spurious associations. Here we study the fecal microbiota of 589 patients at different colorectal cancer (CRC) stages and compare observations with up to 15 published studies (4,439 patients and controls total). Using quantitative microbiome profiling based on 16S ribosomal RNA amplicon sequencing, combined with rigorous confounder control, we identified transit time, fecal calprotectin (intestinal inflammation) and body mass index as primary microbial covariates, superseding variance explained by CRC diagnostic groups. Well-established microbiome CRC targets, such as Fusobacterium nucleatum, did not significantly associate with CRC diagnostic groups (healthy, adenoma and carcinoma) when controlling for these covariates. In contrast, the associations of Anaerococcus vaginalis, Dialister pneumosintes, Parvimonas micra, Peptostreptococcus anaerobius, Porphyromonas asaccharolytica and Prevotella intermedia remained robust, highlighting their future target potential. Finally, control individuals (age 22-80 years, mean 57.7 years, standard deviation 11.3) meeting criteria for colonoscopy (for example, through a positive fecal immunochemical test) but without colonic lesions are enriched for the dysbiotic Bacteroides2 enterotype, emphasizing uncertainties in defining healthy controls in cancer microbiome research. Together, these results indicate the importance of quantitative microbiome profiling and covariate control for biomarker identification in CRC microbiome studies.

Reduction in colorectal cancer incidence by screening endoscopy

Colorectal cancer (CRC) incidence rates decreased by up to 50% in older age groups in the USA in the era of the widespread uptake of screening colonoscopy, despite adverse trends in CRC risk factors and increasing CRC incidence at younger ages. However, reported first results from a randomized trial, the NordICC study, suggested rather modest effects of screening colonoscopy. As outlined in this Perspective, the apparent discrepancy between real-world and trial evidence could be explained by strong attenuation of effect estimates from screening endoscopy trials by several factors, including limited screening adherence, widespread uptake of colonoscopy outside the screening offers and the inclusion of prevalent, non-preventable CRC cases in reported numbers of incident cases. Alternative interpretations of screening endoscopy trial results accounting for prevalence bias are in line with trends in CRC incidence reduction in countries offering CRC screening, and should encourage more widespread implementation and uptake of effective CRC screening.

Colorectal cancer: Genetic alterations, novel biomarkers, current therapeutic strategies and clinical trials

Colorectal cancer (CRC) is the third most commonly detected cancer with a serious global health issue. The rates for incidence and mortality for CRC are alarming, especially since the prognosis is abysmal when the CRC is diagnosed at an advanced or metastatic stage. Both type of (modifiable/ non-modifiable) types of risk factors are established for CRC. Despite the advances in recent technology and sophisticated research, the survival rate is still meager due to delays in diagnosis. Therefore, there is urgently required to identify critical biomarkers aiming at early diagnosis and improving effective therapeutic strategies. Additionally, a complete understanding of the dysregulated pathways like PI3K/Akt, Notch, and Wnt associated with CRC progression and metastasis is very beneficial in designing a therapeutic regimen. This review article focused on the dysregulated signaling pathways, genetics and epigenetics alterations, and crucial biomarkers of CRC. This review also provided the list of clinical trials targeting signaling cascades and therapies involving small molecules. This review discusses up-to-date information on novel diagnostic and therapeutic strategies alongside specific clinical trials.

Glycoproteomics-based liquid biopsy: translational outlook for colorectal cancer clinical management in Southeast Asia

Colorectal cancer (CRC) signifies a significant healthcare challenge in Southeast Asia. Despite advancements in screening approaches and treatment modalities, significant medical gaps remain, ranging from prevention and early diagnosis to determining targeted therapy and establishing personalized approaches to managing CRC. There is a need to expand more validated biomarkers in clinical practice. An advanced technique incorporating high-throughput mass spectrometry as a liquid biopsy to unravel a repertoire of glycoproteins and glycans would potentially drive the development of clinical tools for CRC screening, diagnosis and monitoring, and it can be further adapted to the existing standard-of-care procedure. Therefore this review offers a perspective on glycoproteomics-driven liquid biopsy and its potential integration into the clinical care of CRC in the southeast Asia region.

Stool DNA testing for early detection of colorectal cancer: systematic review using the HTA Core Model® for Rapid Relative Effectiveness Assessment

Background

Stool DNA testing for early detection of colorectal cancer (CRC) is a non-invasive technology with the potential to supplement established CRC screening tests. The aim of this health technology assessment was to evaluate effectiveness and safety of currently CE-marked stool DNA tests, compared to other CRC tests in CRC screening strategies in an asymptomatic screening population.

Methods

The assessment was carried out following the guidelines of the European Network for Health Technology Assessment (EUnetHTA). This included a systematic literature search in MED-LINE, Cochrane and EMBASE in 2018. Manufacturers were asked to provide additional data. Five patient interviews helped assessing potential ethical or social aspects and patients' experiences and preferences. We assessed the risk of bias using QUADAS-2, and the quality of the body of evidence using GRADE.

Results

We identified three test accuracy studies, two of which investigated a multitarget stool DNA test (Cologuard®, compared fecal immunochemical test (FIT)) and one a combined DNA stool assay (ColoAlert®, compared to guaiac-based fecal occult blood test (gFOBT), Pyruvate Kinase Isoenzyme Type M2 (M2-PK) and combined gFOBT/M2-PK). We found five published surveys on patient satisfaction. No primary study investigating screening effects on CRC incidence or on overall mortality was found. Both stool DNA tests showed in direct comparison higher sensitivity for the detection of CRC and (advanced) adenoma compared to FIT, or gFOBT, respectively, but had lower specificity. However, these comparative results may depend on the exact type of FIT used. The reported test failure rates were higher for stool DNA testing than for FIT. The certainty of evidence was moderate to high for Cologuard® studies, and low to very low for the ColoAlert® study which refers to a former version of the product and yielded no direct evidence on the test accuracy for ad-vanced versus non-advanced adenoma.

Conclusions

ColoAlert® is the only stool DNA test currently sold in Europe and is available at a lower price than Cologuard®, but reliable evidence is lacking. A screening study including the current product version of ColoAlert® and suitable comparators would, therefore, help evaluate the effectiveness of this screening option in a European context.

A Focused Clinical Review of Lynch Syndrome

Lynch syndrome (LS) is an autosomal dominant condition that increases an individual's risk of a constellation of cancers. LS is defined when an individual has inherited pathogenic variants in the mismatch repair genes. Currently, most people with LS are undiagnosed. Early detection of LS is vital as those with LS can be enrolled in cancer reduction strategies through chemoprophylaxis, risk reducing surgery and cancer surveillance. However, these interventions are often invasive and require refinement. Furthermore, not all LS associated cancers are currently amenable to surveillance. Historically only those with a strong family history suggestive of LS were offered testing; this has proved far too restrictive. New criteria for testing have recently been introduced including the universal screening for LS in associated cancers. This has increased the number of people being diagnosed with LS but has also brought about unique challenges such as when to consent for germline testing and questions over how and who should carry out the consent. The results of germline testing for LS can be complicated and the diagnostic pathway is not always clear. Furthermore, by testing only those with cancer for LS we fail to identify these individuals before they develop potentially fatal pathology. This review will outline these challenges and explore solutions. Furthermore, we consider the potential future of LS care and the related treatments and interventions which are the current focus of research.

Risk-stratified selection to colonoscopy in FIT colorectal cancer screening: development and temporal validation of a prediction model

BACKGROUND

Faecal immunochemical tests (FITs) yield many false positives and challenge colonoscopy capacity in colorectal cancer (CRC) screening programmes. We aimed to develop a risk-based selection of participants to undergo diagnostic colonoscopy.

METHODS

The study was observational and used registry data from the Danish CRC screening programme. We included all participants invited 2014-2016 with a positive FIT (≥ 20 μg fHb/g) who underwent colonoscopy (n = 56,459). We predicted the risk of CRC or advanced neoplasia (AN) from age, gender and FIT value using logistic regression. We evaluated calibration and discrimination and conducted temporal validation. We compared the number of CRCs and adenomas identified by risk cut-offs and by a corresponding FIT cut-off.

RESULTS

AUCs were 74.9% (95% CI: 73.6; 76.3) and 67.4% (95% CI: 66.8%; 68.0%) for the models predicting CRC and AN in the validation dataset. The cut-off of CRC risk calculated from age, gender and FIT value identified 1.03 times (95% CI: 1.02; 1.05) more CRCs and 1.01 times (95% CI: 1.01; 1.01) more medium/high-risk adenomas compared with the corresponding FIT cut-off.

CONCLUSIONS

With existing data, risk-stratified FIT screening using a risk cut-off instead of a FIT cut-off can slightly improve the selection to colonoscopy of those at highest risk of cancer and adenomas.

Effect of colorectal cancer screening on long-term survival of colorectal cancer patients: Results of the Korea National Cancer Screening Program

The Korea National Cancer Screening Program (KNCSP) provides fecal immunochemical test-based colorectal cancer (CRC) screening for people aged ≥50 years. This study aimed to investigate the long-term survival effects of CRC screening based on screening history and interval time since screening. The study cohort was obtained by linking three national databases, namely the Korea Central Cancer Registry, KNCSP database, and Death Certificate. We included 32 509 CRC patients diagnosed in 2008-2009, who underwent CRC screening via the KNCSP between 2004 and 2009. The patients were followed-up until 2019, and their survival was assessed according to their CRC screening history. Cox proportional hazards regression was used to compare time to deaths among CRC patients according to CRC screening history, after adjusting for covariates. Of the 32 509 patients, 20 022 (61.5%) patients were alive by the end of 2019. Long-term survival was significantly higher among screened patients (68.2%) than non-screened (57.2%) individuals. Compared with never-screened patients, the hazard ratio (HR) for CRC-specific death in screened patients was 0.77 (95% CI%, 0.73-0.80). Lowest HR was observed in screened, localized CRC patients (HR, 0.48; 95% CI, 0.42-0.56); HR for CRC-specific death was the lowest in patients screened within 12 months of diagnosis (HR, 0.70; 95% CI, 0.66-0.74), following which, the HRs increased with increasing time interval. CRC screening was positively associated with favorable prognosis in CRC patients aged 50-79 years. The effects on long-term survival according to interval time was the best among individuals screened within one year before diagnosis. This article is protected by copyright. All rights reserved.

Accuracy of H. pylori fecal antigen test using fecal immunochemical test (FIT)

BACKGROUND

Gastric and colorectal cancer (CRC) are both one of the most common cancers worldwide. In many countries fecal immunochemical tests (FIT)-based CRC screening has been implemented. We investigated if FIT can also be applied for detection of H. pylori, the main risk factor for gastric cancer.

METHODS

This prospective study included participants over 18 years of age referred for urea breath test (UBT). Patients were excluded if they had used antibiotics/bismuth in the past 4 weeks, or a proton pomp inhibitor (PPI) in the past 2 weeks. Participants underwent UBT, ELISA stool antigen test in standard feces tube (SAT), ELISA stool antigen test in FIT tube (Hp-FIT), and blood sampling, and completed a questionnaire on user friendliness. UBT results were used as reference.

RESULTS

A total of 182 patients were included (37.4% male, median age 52.4 years (IQR 22.4)). Of these, 60 (33.0%) tested H. pylori positive. SAT and Hp-FIT showed comparable overall accuracy 71.1% (95%CI 63.2-78.3) vs. 77.6% (95%CI 70.4-83.8), respectively (p = 0.97). Sensitivity of SAT was 91.8% (95%CI 80.4-97.7) versus 94.2% (95%CI 84.1-98.9) of Hp-FIT (p = 0.98). Serology scored low with an overall accuracy of 49.7% (95%CI 41.7-57.7). Hp-FIT showed the highest overall user convenience.

CONCLUSIONS

FIT can be used with high accuracy and sensitivity for diagnosis of H. pylori and is rated as the most convenient test. Non-invasive Hp-FIT test is highly promising for combined upper and lower gastrointestinal (pre-) cancerous screening. Further research should investigate the clinical implications, benefits and cost-effectiveness of such an approach.

Superiority of fecal carcinoembryonic antigen as diagnosis marker for adenomatous polyposis coli and asymptomatic colorectal cancer

BACKGROUND

Non-invasive diagnostic tools of adenomatous polyposis coli (APC) and asymptomatic colorectal cancer (CRC) are urgently needed. Although fecal carcinoembryonic antigen (FCEA) has been documented in some studies, the diagnostic potential for the detection of APC and asymptomatic CRC has not been described yet.

METHODS

This is a retrospective study. The pre-diagnostic serum carcinoembryonic antigen (SCEA) and fecal occult blood test (FOBT) levels were retrospectively analyzed in 212 patients with intestinal diseases group (IDG) and 224 controls. The levels of FCEA across all the studied groups were measured using electronic chemiluminescence immunoassay (ECLIA), and their sensitivity and specificity were used to evaluate their diagnostic potential. The individual diagnostic accuracy of the three indices, as well as their combined diagnostic potential, was compared using the receiver operating characteristic (ROC) curve and chi-square test.

RESULTS

The FCEA had low sensitivity (50%) and high specificity (93.91%) for the diagnosis of IDG, with the area under the curve (AUC) value of 0.781. The AUC of FCEA was higher than that of SCEA for the diagnosis of APC and CRC in the APC, asymptomatic CRC, and APC + CRC-stage I patients. The AUCs of FCEA were 0.708 and 0.691 for the 'double-negative patients' and 'triple-negative patients', respectively. In addition, FCEA could diagnose 45.5% of the 'double-negative' patients, 43.3% of the asymptomatic patients, and 42.9% of the 'triple-negative' patients. The combination of FCEA and FOBT improved the diagnostic value (AUC = 0.916).

CONCLUSION

FCEA has been demonstrated to be a favorable diagnostic marker in intestinal diseases, especially in the APC, asymptomatic CRC, and 'double-negative' or 'triple-negative' CRC patients.

Fecal CEA Has an Advantage in the Diagnosis of Colorectal Cancer at Early Stage

Purpose

Serum carcinoembryonic antigen (SCEA) level is often measured in patients with CRC but suffers from poor sensitivity and specificity as a diagnostic biomarker. CEA is more abundant in stool than in serum, but it has not been widely studied. This study aimed to elucidate the efficacy of fecal CEA (FCEA) as a potential non-invasive biomarker for early diagnosis of CRC.

Materials and Methods

We retrospectively analyzed the determination of FCEA and SCEA levels by electrochemiluminescence. We evaluated the diagnostic accuracy of FCEA and SCEA levels in early-stage CRC patients and healthy controls using ROC curve.

Results

A total of 298 people were included: 115 patients with CRC, 35 patients with adenomatous polyp (APC), 46 patients with non-gastrointestinal cancer (NGC), and 102 healthy controls (HC). The FCEA concentrations in CRC and APC patients were significantly higher than that of NGC and HC, and this is different from SCEA expression in APC and NGC. As a diagnostic biomarker of CRC, FCEA had significantly larger AUC compared with SCEA (.802 vs .735, P  < .001). For identifying early-stage colorectal cancer, FCEA showed better diagnostic efficacy (AUC: .831) than SCEA (AUC: .750), and the combination of the 2 biomarkers was even higher (AUC: .896). The sensitivity of FCEA was higher than that of SCEA (78.7% vs 29.8%). When SCEA was negative, 80.3% of CRC and 54.6% of APC cases could be identified by FCEA.

Conclusion

Compared with SCEA, FCEA has more advantages in the diagnosis of the early stage of colorectal cancer and adenomatous polyps.

Role of gut microbiota in epigenetic regulation of colorectal Cancer

Colorectal cancer (CRC) remains one of the most commonly diagnosed cancers and a leading cause of cancer-related deaths worldwide. The stepwise accumulation of epigenetic alterations in the normal colorectal epithelium has been reported to act as a driving force for the initiation and promotion of tumorigenesis in CRC. From a mechanistic standpoint, emerging evidence indicates that within the colorectal epithelium, the diverse gut microbiota can interact with host cells to regulate multiple physiological processes. In fact, recent studies have found that the gut microbiota represents a potential cause of carcinogenesis, invasion, and metastasis via DNA methylation, histone modifications, and non-coding RNAs - providing an epigenetic perspective for the connection between the gut microbiota and CRC. Herein, we comprehensively review the recent research that provides a comprehensive yet succinct evidence connecting the gut microbiota to CRC at an epigenetic level, including carcinogenic mechanisms of cancer-related microbiota, and the potential for utilizing the gut microbiota as CRC biomarkers. These scientific findings highlight a promising future for manipulating the gut microbiota to improve clinical outcomes in patients suffering from CRC.

Faecal tests in the early detection of colorectal cancer

Colorectal cancer is one of the most common cancers in the world. It is the second most common cause of cancer deaths in both genders in Poland. Screening tests allow for early cancer detection, resulting in reduced mortality and better prognosis. Tests include a stool test for occult blood, checking for biomarkers in faeces, and stool DNA testing. Colonoscopy remains the gold standard in the diagnosis of cancer, both in Poland and around the world. To convince patients of the importance of such testing, it is necessary to have a wider knowledge of all the available diagnostic tests, to understand their advantages and disadvantages. This article will give descriptions of the respective tests and compare their effectiveness in the diagnosis of colorectal cancer.

Colorectal Adenomas-Genetics and Searching for New Molecular Screening Biomarkers

Colorectal cancer (CRC) is a malignant disease with an incidence of over 1.8 million new cases per year worldwide. CRC outcome is closely related to the respective stage of CRC and is more favorable at less advanced stages. Detection of early colorectal adenomas is the key to survival. In spite of implemented screening programs showing efficiency in the detection of early precancerous lesions and CRC in asymptomatic patients, a significant number of patients are still diagnosed in advanced stages. Research on CRC accomplished during the last decade has improved our understanding of the etiology and development of colorectal adenomas and revealed weaknesses in the general approach to their detection and elimination. Recent studies seek to find a reliable non-invasive biomarker detectable even in the blood. New candidate biomarkers could be selected on the basis of so-called liquid biopsy, such as long non-coding RNA, microRNA, circulating cell-free DNA, circulating tumor cells, and inflammatory factors released from the adenoma into circulation. In this work, we focused on both genetic and epigenetic changes associated with the development of colorectal adenomas into colorectal carcinoma and we also discuss new possible biomarkers that are detectable even in adenomas prior to cancer development.

Plausibility of an extensive use of stool DNA test for screening advanced colorectal neoplasia

PURPOSE

FIT-DNA test is supposed to be highly sensitive for advanced colorectal neoplasms and is advocated in some developed countries, but lack extensive use in developing countries.

METHODS

A case control study on stool DNA test for colorectal neoplasms patients was conducted from March 2016 to October 2017 in China. We recruited CRC, colorectal neoplasms and normal controls from ambulatory patients and screening attendees in communities. The stool DNA was tested by a molecular panel similar as ColoGuard in addition to fecal immunochemical test(FIT) in a blinded manner. A risk scoring system was used to determine the positiveness of tests with histological diagnosis as its reference standard.

RESULTS

Eligible subjects included 203 colorectal cancer (CRC), 49 advanced adenoma (AA), 156 non-advanced adenoma(NAA) and 431 normal controls(NC). The FIT-DNA kit detected 97.5% CRC (n = 198, 95% CI = 95.4-99.7) and 53.1% AA (n = 26, 95% CI = 39.1-67.0), with specificity of 89.1% (95% CI = 86.2-92.0) in NC and 88.1% (95% CI = 85.5-90.7) in non-advanced controls. The FIT embedded in the kit alone identified 94.6% (n = 192, 95% CI = 91.5-97.7) CRC and 36.7% AA (n = 18, 95% CI = 23.2-50.2). Consistency of KRAS mutation, BMP3 methylation, NDRG4 methylation in 26 paires stool DNA and CRC tumor DNA were 80.9%, 71.4% and 81.8%, respectively.

CONCLUSION

At the sacrifice of significantly decreased specificity, a FIT-DNA kit may has better sensitivity than FIT for predicting advanced colorectal adenoma, but not for predicting colorectal cancer. More evidences are needed for the extensive use of FIT-DNA testing.

Faecal immunochemical tests (FIT) versus colonoscopy for surveillance after screening and polypectomy: a diagnostic accuracy and cost-effectiveness study

OBJECTIVE

The English Bowel Cancer Screening Programme (BCSP) recommends 3 yearly colonoscopy surveillance for patients at intermediate risk of colorectal cancer (CRC) postpolypectomy (those with three to four small adenomas or one ≥10 mm). We investigated whether faecal immunochemical tests (FITs) could reduce surveillance burden on patients and endoscopy services.

DESIGN

Intermediate-risk patients (60-72 years) recommended 3 yearly surveillance were recruited within the BCSP (January 2012-December 2013). FITs were offered at 1, 2 and 3 years postpolypectomy. Invitees consenting and returning a year 1 FIT were included. Participants testing positive (haemoglobin ≥40 µg/g) at years one or two were offered colonoscopy early; all others were offered colonoscopy at 3 years. Diagnostic accuracy for CRC and advanced adenomas (AAs) was estimated considering multiple tests and thresholds. We calculated incremental costs per additional AA and CRC detected by colonoscopy versus FIT surveillance.

RESULTS

74% (5938/8009) of invitees were included in our study having participated at year 1. Of these, 97% returned FITs at years 2 and 3. Three-year cumulative positivity was 13% at the 40 µg/g haemoglobin threshold and 29% at 10 µg/g. 29 participants were diagnosed with CRC and 446 with AAs. Three-year programme sensitivities for CRC and AAs were, respectively, 59% and 33% at 40 µg/g, and 72% and 57% at 10 µg/g. Incremental costs per additional AA and CRC detected by colonoscopy versus FIT (40 µg/g) surveillance were £7354 and £180 778, respectively.

CONCLUSIONS

Replacing 3 yearly colonoscopy surveillance in intermediate-risk patients with annual FIT could reduce colonoscopies by 71%, significantly cut costs but could miss 30%-40% of CRCs and 40%-70% of AAs.

TRIAL REGISTRATION NUMBER

ISRCTN18040196; Results.

Defensin alpha 6 (DEFA6) is a prognostic marker in colorectal cancer

Defensin alpha 6 (DEFA6) is a member of the alpha defensin family of microbicidal and cytotoxic peptides that defend against bacteria and viruses. Here, we provide a novel function of DEFA6 in tumorigenesis of colorectal cancer (CRC) in vitro and in vivo. Specifically, DEFA6 is highly expressed in both CRC cancer cell lines as well as patient-derived samples at the level of RNA and protein. By shRNA-mediated loss of function of DEFA6, we found that proliferation, migration, invasion, colony forming ability of CRC cell lines were impaired in the absence of DEFA6 in vitro. Furthermore, DEFA6-deficient cancer cells exhibited significantly reduced growth rates compared to control cells in vivo. More importantly, by analyzing 352 patient-derived samples, we revealed that DEFA6 is associated with overall survival rate of CRC patients and thus an independent prognostic marker for CRC. These results suggest that DEFA6 plays an essential oncogenic role in CRC and serves a good therapeutic target for the disease.

A Soft Pneumatic Inchworm Double balloon (SPID) for colonoscopy

The design of a smart robot for colonoscopy is challenging because of the limited available space, slippery internal surfaces, and tortuous 3D shape of the human colon. Locomotion forces applied by an endoscopic robot may damage the colonic wall and/or cause pain and discomfort to patients. This study reports a Soft Pneumatic Inchworm Double balloon (SPID) mini-robot for colonoscopy consisting of two balloons connected by a 3 degrees of freedom soft pneumatic actuator. SPID has an external diameter of 18 mm, a total length of 60 mm, and weighs 10 g. The balloons provide anchorage into the colonic wall for a bio-inspired inchworm locomotion. The proposed design reduces the pressure applied to the colonic wall and consequently pain and discomfort during the procedure. The mini-robot has been tested in a deformable plastic colon phantom of similar shape and dimensions to the human anatomy, exhibiting efficient locomotion by its ability to deform and negotiate flexures and bends. The mini-robot is made of elastomer and constructed from 3D printed components, hence with low production costs essential for a disposable device.

Multiple rounds of one sample versus two sample faecal immunochemical test-based colorectal cancer screening: a population-based study

BACKGROUND

Faecal immunochemical test (FIT)-based colorectal cancer screening requires successive rounds for maximum preventive effect. Advanced neoplasia can bleed intermittently and thus might be missed by single faecal sampling. Few studies have been done on two sample FIT (2-FIT) screening over multiple rounds. Therefore, we compared multiple rounds of one sample FIT (1-FIT) with 2-FIT screening with respect to participation, positive predictive value (PPV), diagnostic yield, and interval colorectal cancer.

METHODS

In this population-based study, a random selection of asymptomatic individuals aged 50-74 years in the Rotterdam-Rijnmond region, Netherlands, were invited by post for four rounds (every 2 years) of 1-FIT or 2-FIT screening. Key exclusion criteria were a history or colorectal cancer or inflammatory bowel disease, colon imaging in the previous 2 years, and life expectancy of less than 5 years. Per round, invitees received one or two FITs to sample either one or two consecutive bowel movements. OC-Sensor Micro (Eiken Chemical Co., Ltd, Japan) FITs were used by all participants, except the fourth round of screening for the 1-FIT cohort, for which participants used either an OC-Sensor or a FOB-Gold (Sentinel Diagnostics, Milan, Italy). A faecal haemoglobin cutoff concentration of 10 μg/g of faeces in at least one test was used for referral for colonoscopy.

FINDINGS

Between 2006 and 2015, of 10 008 invited individuals for the 1-FIT cohort, 9787 were eligible for inclusion, of whom 7310 participated at least once in four successive rounds. Of 3197 invited individuals for the 2-FIT cohort, 3131 were eligible for inclusion, and 2269 participated at least once in four successive rounds. In the 1-FIT screening cohort, 74·7% (7310 of 9787) of invitees participated at least once versus 72·5% (2269 of 3131) of invitees in the 2-FIT cohort (p=0·013). Among participants who participated at least once, the cumulative positivity rate over four rounds was 19·2% (1407 of 7310) for the 1-FIT cohort versus 28·5% (647 of 2269) for the 2-FIT cohort (p<0·0001). The cumulative PPV for advanced neoplasia was 33·0% (432 of 1308 colonoscopies) for the 1-FIT cohort versus 24·2% (147 of 607 colonoscopies) for the 2-FIT cohort (p<0·0001). The cumulative diagnostic yield of advanced neoplasia among invited individuals was 4·4% (432 of 9787) for 1-FIT versus 4·7% (147 of 3131) for 2-FIT screening (p=0·46)). FIT interval colorectal cancers were detected in eight (0·1%) of 7310 participants in the 1-FIT cohort and two (0·1%) of 2269 with 2-FIT screening (p=1·00).

INTERPRETATION

Four rounds of 2-FIT screening with a low faecal haemoglobin cutoff level did not result in a significant increase in diagnostic yield or a decrease in interval colorectal cancers compared with 1-FIT, despite higher colonoscopy demand. Therefore, 1-FIT colorectal cancer screening programmes should be preferred.

FUNDING

None.

Participation and Ease of Use in Colorectal Cancer Screening: A Comparison of 2 Fecal Immunochemical Tests

INTRODUCTION

The impact of fecal immunochemical test (FIT)-based colorectal cancer (CRC) screening on disease incidence and mortality is affected by participation, which might be influenced by ease of use of the FIT. We compared the participation rates and ease of use of 2 different FITs in a CRC screening program.

METHODS

There were two study designs within the Dutch CRC screening program. In a paired cohort study, all invitees received 2 FITs (OC-Sensor, Eiken, Japan, and FOB-Gold, Sentinel, Italy) and were asked to sample both from the same stool. Ease of use of both FITs was evaluated by a questionnaire. In a randomized controlled trial, invitees were randomly allocated to receive one of the 2 FITs to compare participation and analyzability.

RESULTS

Of 42,179 invitees in the paired cohort study, 21,078 (50%) completed 2 tests and 20,727 (98%) returned the questionnaire. FOB-Gold was reported significantly easier to use. More participants preferred FOB-Gold (36%) than OC-Sensor (5%), yet most had no preference (59%; P < 0.001). In the randomized trial, 936 of 1,923 invitees (48.7%) returned the FOB-Gold and 940 of 1,923 invitees (48.9%) returned the OC-Sensor, a difference of -0.2% (confidence interval, -3.4% to 3.0%), well within the pre-specified 5% noninferiority margin (P = 0.001). Only one FOB-Gold (0.1%) and 4 OC-Sensors (0.4%) were not analyzable (P = 0.18).

CONCLUSIONS

Although FOB-Gold was significantly but marginally considered easier to use than OC-Sensor, the number of analyzable tests and the participation rates in organized CRC screening are not affected when either of the FITs is implemented as a primary screening test.

Equivalent Accuracy of 2 Quantitative Fecal Immunochemical Tests in Detecting Advanced Neoplasia in an Organized Colorectal Cancer Screening Program

BACKGROUND & AIMS

Although different brands of fecal immunochemical tests (FITs) are used for colorectal cancer (CRC) screening, few studies have compared their accuracy in detecting advanced neoplasia.

METHODS

We performed a large prospective cohort study within the Dutch national CRC screening program to evaluate 2 quantitative FITs: FOB-Gold (Sentinel, Milan, Italy) and OC-Sensor (Eiken Chemical, Tokyo Japan), from May 2016 through March 2017. We randomly selected 42,179 screening-naïve individuals (55-75 years old), who were asked to perform both FITs themselves using the same bowel movement. Participants with positive results from 1 or both FITs (≥15 μg hemoglobin/gram feces) were invited for colonoscopy examination (reference standard). Equivalence in detection of advanced neoplasia was evaluated with a predefined margin of 0.15%.

RESULTS

Of 42,179 invitees, 22,064 (52%) participated and FITs were completed for 21,078 participants. Of 2112 participants (9.6%) with 1 or 2 positive results from FITs, 1778 (84%) underwent a colonoscopy. Of all invitees, the FOB-Gold test detected advanced neoplasia (confirmed by colonoscopy) in 610 participants (1.45%) and the OC-Sensor detected advanced neoplasia (confirmed by colonoscopy) in 606 participants (1.44%)-an absolute difference of 0.01% (95% confidence interval [CI], -0.06% to 0.08%). Of the 21,078 participants who completed both FITs, 1582 (7.5%) had a positive result from the FOB-Gold test and 1627 (7.7%) a positive result from the OC-Sensor test (P = .140). The relative true-positive rate of FOB-Gold vs OC-Sensor in detecting advanced neoplasia was 0.97 (95% CI, 0.92-1.01) and 0.95 (95% CI, 0.87-1.03) for CRC. The relative false-positive rate of the FOB-Gold test vs the OC-Sensor test in detecting advanced neoplasia was 0.99 (95% CI, 0.93-1.05).

CONCLUSIONS

In a large prospective study of individuals invited for CRC screening in The Netherlands, we found equivalent accuracy of the FOB-Gold FIT vs the OC-Sensor FIT in detecting advanced neoplasia. These results are relevant for selecting FITs for CRC screening programs worldwide. Dutch National Trial Registry: NTR5874.

Microbial markers in colorectal cancer detection and/or prognosis

Colorectal cancer (CRC) is the second leading cause of cancer worldwide. CRC is still associated with a poor prognosis among patients with advanced disease. On the contrary, due to its slow progression from detectable precancerous lesions, the prognosis for patients with early stages of CRC is encouraging. While most robust methods are invasive and costly, actual patient-friendly screening methods for CRC suffer of lack of sensitivity and specificity. Therefore, the development of sensitive, non-invasive and cost-effective methods for CRC detection and prognosis are necessary for increasing the chances of a cure. Beyond its beneficial functions for the host, increasing evidence suggests that the intestinal microbiota is a key factor associated with carcinogenesis. Many clinical studies have reported a disruption in the gut microbiota balance and an alteration in the faecal metabolome of CRC patients, suggesting the potential use of a microbial-based test as a non-invasive diagnostic and/or prognostic tool for CRC screening. This review aims to discuss the microbial signatures associated with CRC known to date, including dysbiosis and faecal metabolome alterations, and the potential use of microbial variation markers for non-invasive early diagnosis and/or prognostic assessment of CRC and advanced adenomas. We will finally discuss the possible use of these markers as predicators for treatment response and their limitations.

A systematic review of clinic and community intervention to increase fecal testing for colorectal cancer in rural and low-income populations in the United States - How, what and when?

BACKGROUND

Interventions to improve fecal testing for colorectal cancer (CRC) exist, but are not yet routine practice. We conducted this systematic review to determine how implementation strategies and contextual factors influenced the uptake of interventions to increase Fecal Immunochemical Tests (FIT) and Fecal Occult Blood Testing (FOBT) for CRC in rural and low-income populations in the United States.

METHODS

We searched Medline and the Cochrane Library from January 1998 through July 2016, and Scopus and clinicaltrials.gov through March 2015, for original articles of interventions to increase fecal testing for CRC. Two reviewers independently screened abstracts, reviewed full-text articles, extracted data and performed quality assessments. A qualitative synthesis described the relationship between changes in fecal testing rates for CRC, intervention components, implementation strategies, and contextual factors. A technical expert panel of primary care professionals, health system leaders, and academicians guided this work.

RESULTS

Of 4218 citations initially identified, 27 unique studies reported in 29 publications met inclusion criteria. Studies were conducted in primary care (n = 20, 74.1%), community (n = 5, 18.5%), or both (n = 2, 7.4%) settings. All studies (n = 27, 100.0%) described multicomponent interventions. In clinic based studies, components that occurred most frequently among the highly effective/effective study arms were provision of kits by direct mail, use of a pre-addressed stamped envelope, client reminders, and provider ordered in-clinic distribution. Interventions were delivered by clinic staff/community members (n = 10, 37.0%), research staff (n = 6, 22.2%), both (n = 10, 37.0%), or it was unclear (n = 1, 3.7%). Over half of the studies lacked information on training or monitoring intervention fidelity (n = 15, 55.6%).

CONCLUSIONS

Studies to improve FIT/FOBT in rural and low-income populations utilized multicomponent interventions. The provision of kits through the mail, use of pre-addressed stamped envelopes, client reminders and in-clinic distribution appeared most frequently in the highly effective/effective clinic-based study arms. Few studies described contextual factors or implementation strategies. More robust application of guidelines to support reporting on methods to select, adapt and implement interventions can help end users determine not just which interventions work to improve CRC screening, but which interventions would work best in their setting given specific patient populations, clinical settings, and community characteristics.

TRIAL REGISTRATION

In accordance with PRISMA guidelines, our systematic review protocol was registered with PROSPERO, the international prospective register of systematic reviews, on April 16, 2015 (registration number CRD42015019557 ).

Barriers to Colorectal Cancer Screening in a Primary Care Setting in Turkey

Colorectal cancer (CRC) is the third most common form of cancer in men worldwide and the second most common in women. The purpose of this study was to determine both barriers established by primary health care providers (PHCPs) and barriers perceived by them and to produce solutions for achieving the desired results. A four-part questionnaire was administered to family physicians (FPs) and family health personnels (FHPs) in Samsun, Turkey on 01-15 May, 2016. Sixty-six percent of PHCPs were contacted. Data were evaluated as numbers and percentages, and statistical significance was analyzed using the Chi square and t tests. 478 PHCPs participated; 49.4 % were FPs and 50.6 % FHPs. Of the participants, 86.6 % stated that they performed CRC screening on patients. The level of participants knowing that screening should start at age 50 and conclude at age 70 was 49.7 %. The level of subjects requesting the fecal occult blood test (FOBT) at the correct intervals was 29.7 %, but only 6.9 % recommended colonoscopy at the correct intervals. Additionally, 18.2 % of subjects knew that the test used is immunochemical FOBT, and 60.5 % reported not using reminders. PHCPs' low levels of knowledge, awareness and advice compatible with guidelines concerning CRC screening may represent an obstacle to such screening. Barriers perceived by PHCPs include patients' inability to access definite medical information, deficiencies in the reminder system and patients' lack of interest in CRC screening. Additions to the screening program will be useful in overcoming barriers.

Colorectal Cancer Screening-Who, How, and When?

Colorectal cancer (CRC) is the third most common cancer worldwide. It is amenable to screening as it occurs in premalignant, latent, early, and curable stages. PubMed, Cochrane Database of Systematic Reviews, and national and international CRC screening guidelines were searched for CRC screening methods, populations, and timing. CRC screening can use direct or indirect tests, delivered opportunistically or via organized programs. Most CRCs are diagnosed after 60 years of age; most screening programs apply to individuals 50-75 years of age. Screening may reduce disease-specific mortality by detecting CRC in earlier stages, and CRC incidence by detecting premalignant polyps, which can subsequently be removed. In randomized controlled trials (RCTs) guaiac fecal occult blood testing (gFOBt) was found to reduce CRC mortality by 13%-33%. Fecal immunochemical testing (FIT) has no RCT data comparing it to no screening, but is superior to gFOBt. Flexible sigmoidoscopy (FS) trials demonstrated an 18% reduction in CRC incidence and a 28% reduction in CRC mortality. Currently, RCT evidence for colonoscopy screening is scarce. Although not yet corroborated by RCTs, it is likely that colonoscopy is the best screening modality for an individual. From a population perspective, organized programs are superior to opportunistic screening. However, no nation can offer organized population-wide colonoscopy screening. Thus, organized programs using cheaper modalities, such as FS/FIT, can be tailored to budget and capacity.

Colonoscopy overuse in colorectal cancer screening and associated factors in Argentina: a retrospective cohort study

Background

In recent years, there has been growing concern about the overuse of colonoscopy (CC). Our objective was to evaluate the incidence rate and cumulative probability of having a potentially inadequate CC (PI-CC, e.g. a CC that was performed earlier that recommended) and the association between the report of a hyperplastic polyp in the baseline CC report and the probability of having a PI-CC.

Methods

A retrospective cohort of adults 50y/o or older with a complete baseline CC between January 1st and December 31st 2005, without reported lesions or with hyperplastic polyps, based on secondary data extracted from the electronic medical record of the Hospital Italiano of Buenos Aires. The outcome consisted of time until a PI-CC, defined as the time measured between basal colonoscopy and a colonoscopy performed earlier than the inter-screening interval recommended by the USPSTF and the USMSTF.

Results

389 patients were included. The cumulative probability of receiving a PI-CC over 10 years was 0.29 (95% CI 0.241, 0.342). The incidence rate resulted in 30.91 PI-CC per 1000 person-years (95% CI 25.14, 38). The crude analysis of the association between the outcome and the presence of hyperplastic polyps in the baseline CC, showed a statistically significant difference between both groups (log rank, p 0.036). The multivariate analysis yielded a hazard ratio of 1.67 (95% CI 1.02–2.73).

Conclusion

We observed that 3 in every 10 patients treated in our health system received a PI-CC during the first ten consecutive years after a normal complete CC. Furthermore, this could be in part attributed to the presence of a hyperplastic polyp in the baseline CC.

Proteomics for early detection of colorectal cancer: recent updates

INTRODUCTION

Colorectal cancer (CRC) is a common type of cancer with a relatively poor survival rate. The survival rate of patients could be improved if CRC is detected early. Biomarkers associated with early stages of tumor development might provide useful tools for the early diagnosis of colorectal cancer. Areas covered: Online searches using PubMed and Google Scholar were performed using keywords and with a focus on recent proteomic studies. The aim of this review is to highlight the need for biomarkers to improve the detection rate of early CRC and provide an overview of proteomic technologies used for biomarker discovery and validation. This review will also discuss recent proteomic studies which focus on identifying biomarkers associated with the early stages of CRC development. Expert commentary: A large number of CRC biomarkers are increasingly being identified by proteomics using diverse approaches. However, the clinical relevance and introduction of these markers into clinical practice cannot be determined without a robust validation process. The size of validation cohorts remains a major limitation in many biomarker studies.

Current Tissue Molecular Markers in Colorectal Cancer: A Literature Review

BACKGROUND

Colorectal cancer (CRC) is one of the most spread neoplasia types all around the world, especially in western areas. It evolves from precancerous lesions and adenomatous polyps, through successive genetic and epigenetic mutations. Numerous risk factors intervene in its development and they are either environmental or genetic.

AIM OF THE REVIEW

Alongside common screening techniques, such as fecal screening tests, endoscopic evaluation, and CT-colonography, we have identified the most important and useful biomarkers and we have analyzed their role in the diagnosis, prevention, and prognosis of CRC.

CONCLUSION

Biomarkers can become an important tool in the diagnostic and therapeutic process for CRC. But further studies are needed to identify a noninvasive, cost-effective, and highly sensible and specific screening test for their detection and to standardize their use in clinical practice.

Global and targeted serum metabolic profiling of colorectal cancer progression

BACKGROUND

Patients with colorectal adenoma polyps (PLPs) are at higher risk for developing colorectal cancer (CRC). However, the development of improved and robust biomarkers to enable the screening, surveillance, and early detection of PLPs and CRC continues to be a challenge. The aim of this study was to identify biomarkers of progression to CRC through metabolomic profiling of human serum samples with a multistage approach.

METHODS

Metabolomic profiling was conducted with the Metabolon platform for 30 CRC patients, 30 PLP patients, and 30 control subjects, and this was followed by the targeted validation of the top metabolites in an additional set of 50 CRC patients, 50 PLP patients, and 50 controls with liquid chromatography-tandem mass spectrometry. Unconditional multivariate logistic regression models, adjusted for covariates, were used to evaluate associations with PLP and CRC risk.

RESULTS

For the discovery phase, 404 serum metabolites were detected, with 50 metabolites showing differential levels between CRC patients, PLP patients, and controls (P for trend < .05). After validation, the 3 top metabolites (xanthine, hypoxanthine, and d-mannose) were validated: lower levels of xanthine and hypoxanthine and higher levels of d-mannose were found in PLP and CRC cases versus controls. A further exploratory analysis of metabolic pathways revealed key roles for the urea cycle and caffeine metabolism associated with PLP and CRC risk. In addition, a joint effect of the top metabolites with smoking and a significant interaction with the body mass index were observed. An analysis of the ratio of hypoxanthine levels to xanthine levels indicated an association with CRC progression.

CONCLUSIONS

These results suggest the potential utility of circulating metabolites as novel biomarkers for the early detection of CRC. Cancer 2017;123:4066-74. © 2017 American Cancer Society.

Predictive and prognostic biomarkers in colorectal cancer: A systematic review of recent advances and challenges

BACKGROUND

Colorectal cancer (CRC) is one of the leading cause of cancer deaths worldwide. Since CRC is largely asymptomatic until alarm features develop to advanced stages, the implementation of the screening programme is very much essential to reduce cancer incidence and mortality rates. CRC occurs predominantly from accumulation of genetic and epigenetic changes in colon epithelial cells, which later gets transformed into adenocarcinomas.

SCOPE OF REVIEW

The current challenges of screening paradigm and diagnostic ranges are from semi-invasive methods like colonoscopy to non-invasive stool-based test, have resulted in over-diagnosis and over-treatment of CRC. Hence, new screening initiatives and deep studies are required for early diagnosis of CRC. In this regard, we not only summarise current predictive and prognostic biomarkers with their potential for diagnostic and therapeutic applications, but also describe current limitations, future perspectives and challenges associated with the progression of CRC.

MAJOR CONCLUSIONS

Currently many potential biomarkers have already been successfully translated into clinical practice eg. Fecal haemoglobin, Carcinoembryonic antigen (CEA) and CA19.9, although these are not highly promising diagnostic target for personalized medicine. So there is a critical need for reliable, minimally invasive, highly sensitive and specific genetic markers of an individualised and optimised patient treatment at the earliest disease stage possible.

GENERAL SIGNIFICANCE

Identification of a new biomarker, or a set of biomarkers to the development of a valid, and clinical sensible assay that can be served as an alternative tool for early diagnosis of CRC and open up promising new targets in therapeutic intervention strategies.