A Comparison of Fecal Immunochemical and High-Sensitivity Guaiac Tests for Colorectal Cancer Screening

Repeat Faecal Immunochemical Testing for Colorectal Cancer Detection in Symptomatic and Screening Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Faecal immunochemical testing (FIT) is widely used in bowel screening programmes and assessing symptomatic patients for suspected colorectal cancer (CRC). The evidence for single test performance of FIT in both settings is considerable; however, the use of a repeat test to increase sensitivity remains uncertain. We aimed to review what increase in test positivity would be generated by additional FITs, whether a repeated FIT detects previously missed CRC and advanced colorectal neoplasia (ACRN), and to estimate the sensitivity of double-FIT strategies to diagnose CRC and ACRN.

METHODS

A systematic search of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) was performed using key search terms. Studies reporting the use of more than one FIT in the same screening round or planned assessment of a single symptomatic patient episode were included. Studies were categorised by the reported study population into asymptomatic, mixed (cohorts of combined asymptomatic, symptomatic, or high-risk surveillance), or symptomatic cohorts.

RESULTS

A total of 68 studies were included for analysis (39 asymptomatic, 21 mixed, 7 symptomatic, and 1 study with discrete asymptomatic and symptomatic data). At a threshold of 10 µg Hb/g, the two-test positivity ranged between 8.1 and 34.5%, with an increase from the second test of 3-9.2 percentage points. Four out of five studies comparing one versus two tests for diagnosing CRC at 10 µg Hb/g identified additional cases with the second test, with a minimum of 50% reduction in missed CRC. At a threshold of 20 µg Hb/g, the second test increased the positivity by 1.3-6.7 percentage points, with a two-test positivity of between 5.1 and 25.0%. Using a threshold of 20 µg Hb/g, five out of seven studies had a 25% reduction in missed CRC. A meta-analysis estimated the double-FIT sensitivity at 10 µg Hb/g for CRC in mixed-risk and symptomatic cohorts to be 94% and 98%, respectively.

CONCLUSIONS

Repeated use of FIT helps to diagnose more cases of CRC with a moderate increase in positivity. A double-FIT strategy at 10 µg Hb/g in mixed and symptomatic cohorts has a very high sensitivity for CRC.

Effect of fecal immunochemical test cut-off levels on adenoma detection rate: a systematic review and meta-analysis

BACKGROUND

Adenoma detection rate (ADR) is higher after a positive fecal immunochemical test (FIT) compared to direct screening colonoscopy.

OBJECTIVE

This meta-analysis evaluated how ADR, the rates of advanced adenoma detection (AADR), colorectal cancer detection (CDR), and sessile serrated lesion detection (SSLDR) are affected by different FIT positivity thresholds.

METHODS

We searched MEDLINE, EMBASE, CINAHL, and EBM Reviews databases for studies reporting ADR, AADR, CDR, and SSLDR according to different FIT cut-off values in asymptomatic average-risk individuals aged 50-74 years old. Data were stratified according to sex, age, time to colonoscopy, publication year, continent, and FIT kit type. Study quality, heterogeneity, and publication bias were assessed.

RESULTS

Overall, 4280 articles were retrieved and fifty-eight studies were included (277,661 FIT-positive colonoscopies; mean cecal intubation 96.3%; mean age 60.8 years; male 52.1%). Mean ADR was 56.1% (95% CI 53.4 - 58.7%), while mean AADR, CDR, and SSLDR were 27.2% (95% CI 24.4 - 30.1%), 5.3% (95% CI 4.7 - 6.0%), and 3.0% (95% CI 1.7 - 4.6%), respectively. For each 20 μg Hb/g increase in FIT cut-off level, ADR increased by 1.54% (95% CI 0.52 - 2.56%, p < 0.01), AADR by 3.90% (95% CI 2.76 - 5.05%, p < 0.01) and CDR by 1.46% (95% CI 0.66 - 2.24%, p < 0.01). Many detection rates were greater amongst males and Europeans.

CONCLUSIONS

ADRs in FIT-positive colonoscopies are influenced by the adopted FIT positivity threshold, and identified targets, importantly, proved to be higher than most current societal recommendations.

Screening of colorectal cancer: Methods and strategies

Colorectal cancer (CRC) has high incidence and mortality rates, and the emergence and application of CRC screening have helped us effectively control the occurrence and development of CRC. Currently, common international screening methods include tests based on feces and blood, and examination methods that allow for visualization, such as sigmoidoscopy and colonoscopy. Some methods have been widely used, whereas others such as multi-target stool RNA test are still being explored and developed, and are expected to become front-line screening methods for CRC in the future. The choice of screening method is affected by external conditions and the patients' situation, and the clinician must choose an appropriate strategy according to the actual situation and the patient's wishes. This article introduces various CRC screening methods and analyzes the factors relevant to the screening strategy.

Why is early detection of colon cancer still not possible in 2023?

Colorectal cancer (CRC) screening is a fundamental tool in the prevention and early detection of one of the most prevalent and lethal cancers. Over the years, screening, particularly in those settings where it is well organized, has succeeded in reducing the incidence of colon and rectal cancer and improving the prognosis related to them. Despite considerable advancements in screening technologies and strategies, the effectiveness of CRC screening programs remains less than optimal. This paper examined the multifaceted reasons behind the persistent lack of effectiveness in CRC screening initiatives. Through a critical analysis of current methodologies, technological limitations, patient-related factors, and systemic challenges, we elucidated the complex interplay that hampers the successful reduction of CRC morbidity and mortality rates. While acknowledging the advancements that have improved aspects of screening, we emphasized the necessity of addressing the identified barriers comprehensively. This study aimed to raise awareness of how important CRC screening is in reducing costs for this disease. Screening and early diagnosis are not only important in improving the prognosis of patients with CRC but can lead to an important reduction in the cost of treating a disease that is often diagnosed at an advanced stage. Spending more sooner can mean saving money later.

Predictive biomarkers for colorectal cancer: a state-of-the-art systematic review

INTRODUCTION

Colorectal cancer (CRC) poses a substantial health burden, with early detection paramount for improved prognosis. This study aims to evaluate potential CRC biomarkers and detection techniques.

MATERIALS AND METHODS

This systematic review, reported in adherence to PRISMA Statement 2020 guidelines, collates the latest research on potential biomarkers and detection/prognosis methods for CRC, spanning the last decade.

RESULTS

Out of the 38 included studies, diverse biomarkers and detection methods emerged, with DNA methylation markers like SFRP2 and SDC2, microRNAs including miR-1290, miR-506, and miR-4316, and serum and plasma markers such as NTS levels and U2 snRNA fragments standing out. Methylated cfDNA and m5C methylation alteration in immune cells of the blood, along with circular RNA, showed promise as diagnostic markers. Meanwhile, techniques involving extracellular vesicles and lateral flow immunoassays exhibited potential for swift and effective CRC screening.

DISCUSSION

Our state-of-the-art review identifies potential biomarkers, including SFRP2, SDC2, miR-1290, miR-506, miR-4316, and U2 snRNA fragments, with significant potential in enhancing CRC detection. However, comprehensive validation studies and a rigorous evaluation of clinical utility and cost-effectiveness remain necessary before integration into routine clinical practice.

CONCLUSION

The findings emphasize the need for continued research into biomarkers and detection methods to improve patient outcomes.

Combined detection of SDC2/ADHFE1/PPP2R5C methylation in stool DNA for colorectal cancer screening

BACKGROUND

Colorectal cancer (CRC) is a disease of global concern, and its increasing incidence suggests the need for early and accurate diagnosis. The aim of this study was to investigate the value of combined detection of SDC2, ADHFE1 and PPP2R5C gene methylation in stool samples for early CRC screening.

METHODS

Stool samples from patients with CRC (n = 105), advanced adenoma (AA) (n = 54), non-advanced adenoma (NA) (n = 57), hyperplastic or other polyps (HOP) (n = 47) or no evidence of disease (NED) (n = 100) were collected from September 2021 to September 2022. The methylation levels of SDC2, ADHFE1 and PPP2R5C were quantified by quantitative methylation-specific polymerase chain reaction (qMSP), and faecal immunochemical testing (FIT) was performed. The diagnostic value was assessed using reporter operating characteristic (ROC) curve analysis.

RESULTS

The sensitivity of combined detection of SDC2/ADHFE1/PPP2R5C methylation in predicting CRC (0-IV) was 84.8%, the specificity was 98.0%, and the AUC was 0.930 (95% CI 0.889-0.970). Compared to FIT and serum tumour biomarkers, it showed better diagnostic performance for different stages of CRC.

CONCLUSION

The results of this study verified that the methylation levels of SDC2, ADHFE1 and PPP2R5C in stool DNA were significantly increased in CRC patients. Combined detection of SDC2/ADHFE1/PPP2R5C methylation is a potential non-invasive diagnostic method for CRC and precancerous lesion screening.

CLINICAL TRIAL REGISTRATION

Chinese Clinical Trials Registry, ChiCTR2100046662, registered on 26 May 2021, prospective registration.

Reducing disparities and achieving health equity in colorectal cancer screening

Increases in colorectal cancer screening are linked to the declining incidence of the disease over the past three decades. These favorable trends, however, are not observed in marginalized racial and ethnic populations with disproportionately lower rates of screening, higher disease incidence, and increased mortality despite advances in health technology and policy. This review describes the differences in screening uptake and test selection amongst racial and ethnic groups, discusses known obstacles and facilitators that impact screening, and highlights existing frameworks developed to achieve health equity in colorectal cancer screening.

Sessile serrated lesion detection rates continue to increase: 2008-2020

Background and study aims  We assessed sessile serrated lesion detection rate (SSLDR) at a large academic medical center from 2008 to 2020 and modeled a local, aspirational target SSLDR. We also assessed SSLDRs among all gastroenterology fellows to better understand the relationship between SSLDRs and total colonoscopies performed. Patients and methods  SSL-positive pathology results were flagged from a dataset composed of all screening colonoscopies for average-risk patients from 2008 to 2020. Unadjusted SSLDRs were calculated for individual endoscopists by year. A mixed effects logistic regression was used to estimate the log odds of SSL detection, with one model estimating division-wide predictors of SSL detection and a second model focused exclusively on colonoscopies performed by fellows. Model-adjusted SSLDRs were estimated for all 13 years and across both categories of all endoscopists and fellows only. Results  Adjusted SSLDRs showed a consistent improvement in SSLDR from a low of 0.37 % (95 % confidence interval [CI]: 0.10-0.63) in 2008 to a high of 7.94 % (95 % CI: 6.34-9.54) in 2020. Among fellows only, the odds of SSL detection were significantly lower during their first year compared to their second year (OR: 0.80, 95 % CI: 0.66-0.98) but not significantly higher in their third year compared to their second year (OR: 1.09, 95 % CI: 0.85-1.4). Conclusions  SSLDR increased steadily and significantly throughout our study period but variance among endoscopists persists. The peak SSLDR from 2020 of 7.94 % should serve as the local aspirational target for this division's attendings and fellows but should be continuously reevaluated.

Potential Modifiers and Different Cut-offs in Diagnostic Accuracy of Fecal Immunochemical Test in Detecting Advanced Colon Neoplasia: A Diagnostic Test Accuracy Meta-analysis

Background: Fecal immunoglobulin test (FIT) has been advocated as the first line of screening for colorectal cancer (CRC) in several jurisdictions. Most studies have focused on CRC as the outcome of interest. Our goal was to quantify the diagnostic accuracy of different thresholds of FIT as compared with colonoscopy for detection of advanced colonic neoplasia and potential modifiers using proper Cochrane methodology. Methods: A comprehensive electronic search was performed for studies on FIT using colonoscopy as the reference standard to detect advanced neoplasia. Cochrane methodology was used to perform a diagnostic test accuracy (DTA) meta-analysis. Diagnostic accuracy of different cut-offs of FIT, including 25, 50, 75, 100, 150, and 200 ng/mL, were calculated separately. Meta-regression analysis was also performed to detect potential a priori modifiers, including age, location of the tumor, and time from FIT to colonoscopy. Results: Twenty-four studies were included with no evidence of publication bias. The sensitivity of FIT did not decrease with lowering the cut-off, although specificity increased in higher cut-offs. Commonly used cut-offs of 50 ng/mL, 75 ng/mL, and 100 ng/mL for FIT provided sensitivity of 39%, 36%, 27% and specificity of 92%, 94%, 96%, respectively. Diagnostic accuracy of FIT did not significantly differ in proximal versus distal lesions or in individuals below or over the age of 50 years. The results remained robust in a meta-regression of the location of the study, time from FIT to colonoscopy, and methodological quality. Conclusion: The sensitivity of FIT might have been overestimated in previous studies focusing on CRC, and it seems to be independent of age, location of neoplasia, or cut-offs, contrary to some previous studies. Lowering the cut-off will reduce the diagnostic odds ratio (DOR) by increasing specificity but without any effect on sensitivity.

Assessing Suitability of a Colorectal Cancer Screening Program in Oman

Colorectal cancer is among the most common cancers globally and carries a high mortality rate. The incidence of colorectal cancer has been increasing in the Middle East, including in Oman. While many countries have implemented a bowel cancer screening program, Oman has yet to establish one. A standard tool for bowel cancer screening is a fecal immunochemical test where a fecal sample is sent to a laboratory to check for blood content in the feces. In Oman, such fecal test kits are available at the primary health care level, but primary care physicians were unaware of the signs and symptoms or screening methods for colorectal cancer. This review article aims to assess the suitability of a colorectal cancer screening program in Oman using guidelines from the Supporting the Use of Research Evidence (SURE) collaboration.

Advances in tests for colorectal cancer screening and diagnosis

INTRODUCTION

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths globally. Nonetheless, with early detection of CRC or its precancerous lesions, mortality, and CRC incidence can be reduced. Although colonoscopy is currently the gold standard for CRC screening and diagnosis, its invasive nature, and troublesome bowel preparation deter patient participation. Therefore, there is a need to expand the use of noninvasive or minimally invasive methods to increase patient compliance.

AREAS COVERED

This review summarizes advances in different methods for CRC screening, including stool bacterial and metagenomic markers, fecal proteins, genetic and epigenetic markers in blood and stools, and imaging modalities. The cost-effectiveness of these methods is also discussed. FIT is more cost-effective compared to virtual colonoscopy, mSEPT9 test, and Multitarget Stool DNA test, while the cost-effectiveness of other noninvasive methods requires further evaluation.

EXPERT OPINION

Recent evidence has well demonstrated the usefulness of gut microbiome and certain fecal bacterial markers in the noninvasive diagnosis of CRC and its precancerous lesions. Many of the fecal biomarkers, from host cells or the gut environment, show better diagnostic sensitivity than FIT. New screening tests based on these fecal biomarkers can be expected to replace FIT with higher cost-effectiveness in the near future.

Effectiveness and Harms of Colorectal Cancer Screening Strategies

Colorectal cancer screening incorporates various testing modalities. Factors including effectiveness, harms, cost, screening interval, patient preferences, and test availability should be considered when determining which test to use. Fecal occult blood testing and endoscopic screening have the most robust evidence, while newer blood- and imaging-based techniques require further evaluation. In this review, we compare the effectiveness, harms, and costs of the various screening strategies.

Evaluation of fecal SYPL1 as a diagnostic biomarker in colorectal cancer

BACKGROUND

At present, there is still no ideal non-invasive biomarker for colorectal cancer (CRC) screening. Previously, we foundserum synaptophysin like 1 (SYPL1) served as a potential biomarker for CRC diagnosis. However, whether fecal SYPL1 (fSYPL1) are more sensitive and specific for CRC remains unclear.

METHODS

We analyzed fSYPL1 in controls (n = 70), adenoma patients (n = 80), CRC patients (n = 150) and postoperative CRC patients (n = 25) by ELISA.

RESULTS

SYPL1 was stable in feces. The fSYPL1 levels were significantly higher in CRC patients than in either controls or adenoma patients (P < 0.0001). ROC curves showed that fSYPL1 performed superbly in distinguishing CRC patients from controls (AUC = 0.947; 95% CI: 0.920 - 0.974, P < 0.0001, sensitivity: 80.67%, specificity: 100.00%), which showed much stronger performance than the traditional biomarkers (FOBT, CEA and CA19-9). Meanwhile, the fSYPL1 level positively correlated with tumor size, tumor invasion, lymph node invasion and clinical stage (P < 0.05). In addition, the detection rate of fSYPL1 was high in early CRC (75.00% in stage I and II). The fSYPL1 levels in CRC patients declined substantially after surgery (P = 0.0002). By means of a lower cut off level, 73.58% of high-risk adenomas were detected. The combination of fSYPL1 and FOBT performed better than the combination of plasma SYPL1, CEA and CA199 in distinguishing CRC patients from controls.

CONCLUSION

The fSYPL1 might be a potential biomarker for CRC screening, early diagnosis, prognosis prediction and therapeutic effect monitoring.

Alterations in the Gut Microbiota and Their Metabolites in Colorectal Cancer: Recent Progress and Future Prospects

Colorectal cancer (CRC) is a leading cause of cancer morbidity and mortality worldwide. The etiology and pathogenesis of CRC remain unclear. A growing body of evidence suggests dysbiosis of gut bacteria can contribute to the occurrence and development of CRC by generating harmful metabolites and changing host physiological processes. Metabolomics, a systems biology method, will systematically study the changes in metabolites in the physiological processes of the body, eventually playing a significant role in the detection of metabolic biomarkers and improving disease diagnosis and treatment. Metabolomics, in particular, has been highly beneficial in tracking microbially derived metabolites, which has substantially advanced our comprehension of host-microbiota metabolic interactions in CRC. This paper has briefly compiled recent research progress of the alterations of intestinal flora and its metabolites associated with CRC and the application of association analysis of metabolomics and gut microbiome in the diagnosis, prevention, and treatment of CRC; furthermore, we discuss the prospects for the problems and development direction of this association analysis in the study of CRC. Gut microbiota and their metabolites influence the progression and causation of CRC, and the association analysis of metabolomics and gut microbiome will provide novel strategies for the prevention, diagnosis, and therapy of CRC.

Dysbiosis of human gut microbiome in young-onset colorectal cancer

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

Nanotechnology in Colorectal Cancer for Precision Diagnosis and Therapy

Colorectal cancer (CRC) is the third most frequently occurring tumor in the human population. CRCs are usually adenocarcinomatous and originate as a polyp on the inner wall of the colon or rectum which may become malignant in the due course of time. Although the therapeutic options of CRC are limited, the early diagnosis of CRC may play an important role in preventive and therapeutic interventions to decrease the mortality rate. The CRC-affected tissues exhibit several molecular markers that may be exploited as the novel strategy to develop newer approaches for the treatment of the disease. Nanotechnology consists of a wide array of innovative and astonishing nanomaterials with both diagnostics and therapeutic potential. Several nanomaterials and nano formulations such as Carbon nanotubes, Dendrimer, Liposomes, Silica Nanoparticles, Gold nanoparticles, Metal-organic frameworks, Core-shell polymeric nano-formulations, Nano-emulsion System, etc can be used to targeted anticancer drug delivery and diagnostic purposes in CRC. The light-sensitive photosensitizer drugs loaded gold and silica nanoparticles can be used to diagnose as well as the killing of CRC cells by the targeted delivery of anticancer drugs to cancer cells. This review is focused on the recent advancement of nanotechnology in the diagnosis and treatment of CRC.

Screening and prevention of colorectal cancer

Mortality from colorectal cancer is reduced through screening and early detection; moreover, removal of neoplastic lesions can reduce cancer incidence. While understanding of the risk factors, pathogenesis, and precursor lesions of colorectal cancer has advanced, the cause of the recent increase in cancer among young adults is largely unknown. Multiple invasive, semi- and non-invasive screening modalities have emerged over the past decade. The current emphasis on quality of colonoscopy has improved the effectiveness of screening and prevention, and the role of new technologies in detection of neoplasia, such as artificial intelligence, is rapidly emerging. The overall screening rates in the US, however, are suboptimal, and few interventions have been shown to increase screening uptake. This review provides an overview of colorectal cancer, the current status of screening efforts, and the tools available to reduce mortality from colorectal cancer.

Low Rates of Colonoscopy Follow-up After a Positive Fecal Immunochemical Test in a Medicaid Health Plan Delivered Mailed Colorectal Cancer Screening Program

BACKGROUND

Follow-up colonoscopy after a positive fecal immunochemical test (FIT) is necessary for colorectal cancer (CRC) screening to be effective. We report colonoscopy follow-up rates after a positive FIT overall and by population characteristics in the BeneFIT demonstration pilot, a Medicaid health insurance plan-delivered mailed FIT outreach program.

METHODS

In 2016, 2 health insurance plans in Oregon and in Washington state mailed FIT kits to Medicaid patients who, based on claims data, were overdue for CRC screening. We report follow-up colonoscopy completion rates after positive FIT, and differences in completion rates by age, sex, race, ethnicity, preferred language, and number of primary care visits in the prior year. This research was human subjects approved with a waiver of consent for data collection.

RESULTS

The FIT positivity rates in Health Plan Oregon and Health Plan Washington were 7.9% (39/488) and 14.6% (125/857), respectively. Colonoscopy completion rates within 12 months of the positive test were 35.9% (14/41) in Health Plan Oregon and 32.8% (41/125) in Health Plan Washington. Colonoscopy completion rates were higher among individuals who preferred a language other than English (Non-English speakers 70.0%, English speakers 31.3%, P = .04).

CONCLUSION

In a health plan-delivered mailed FIT outreach program, follow-up colonoscopy rates after a positive test were low. Additional interventions are needed to assure colonoscopy after a positive FIT test and to reap the benefits of screening.

Screening for Colorectal Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Colorectal cancer (CRC) remains a significant cause of morbidity and mortality in the US.

OBJECTIVE

To systematically review the effectiveness, test accuracy, and harms of screening for CRC to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials for relevant studies published from January 1, 2015, to December 4, 2019; surveillance through March 26, 2021.

STUDY SELECTION

English-language studies conducted in asymptomatic populations at general risk of CRC.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently appraised the articles and extracted relevant study data from fair- or good-quality studies. Random-effects meta-analyses were conducted.

MAIN OUTCOMES AND MEASURES

Colorectal cancer incidence and mortality, test accuracy in detecting cancers or adenomas, and serious adverse events.

RESULTS

The review included 33 studies (n = 10 776 276) on the effectiveness of screening, 59 (n = 3 491 045) on the test performance of screening tests, and 131 (n = 26 987 366) on the harms of screening. In randomized clinical trials (4 trials, n = 458 002), intention to screen with 1- or 2-time flexible sigmoidoscopy vs no screening was associated with a decrease in CRC-specific mortality (incidence rate ratio, 0.74 [95% CI, 0.68-0.80]). Annual or biennial guaiac fecal occult blood test (gFOBT) vs no screening (5 trials, n = 419 966) was associated with a reduction of CRC-specific mortality after 2 to 9 rounds of screening (relative risk at 19.5 years, 0.91 [95% CI, 0.84-0.98]; relative risk at 30 years, 0.78 [95% CI, 0.65-0.93]). In observational studies, receipt of screening colonoscopy (2 studies, n = 436 927) or fecal immunochemical test (FIT) (1 study, n = 5.4 million) vs no screening was associated with lower risk of CRC incidence or mortality. Nine studies (n = 6497) evaluated the test accuracy of screening computed tomography (CT) colonography, 4 of which also reported the test accuracy of colonoscopy; pooled sensitivity to detect adenomas 6 mm or larger was similar between CT colonography with bowel prep (0.86) and colonoscopy (0.89). In pooled values, commonly evaluated FITs (14 studies, n = 45 403) (sensitivity, 0.74; specificity, 0.94) and stool DNA with FIT (4 studies, n = 12 424) (sensitivity, 0.93; specificity, 0.85) performed better than high-sensitivity gFOBT (2 studies, n = 3503) (sensitivity, 0.50-0.75; specificity, 0.96-0.98) to detect cancers. Serious harms of screening colonoscopy included perforations (3.1/10 000 procedures) and major bleeding (14.6/10 000 procedures). CT colonography may have harms resulting from low-dose ionizing radiation. It is unclear if detection of extracolonic findings on CT colonography is a net benefit or harm.

CONCLUSIONS AND RELEVANCE

There are several options to screen for colorectal cancer, each with a different level of evidence demonstrating its ability to reduce cancer mortality, its ability to detect cancer or precursor lesions, and its risk of harms.

Impact of changing from a guaiac faecal occult blood test to a faecal immunochemical test in a national screening programme: Results from a pilot study within the national bowel cancer screening programme in England

OBJECTIVE

Testing for occult blood in faeces is widely used in bowel cancer screening around the world. In many programmes, the faecal immunochemical test (FIT) is replacing the traditional guiaic faecal occult blood test (gFOBT). There have been a number of reports on the clinical impact of making this change; yet, no-one has considered the pre-analytical and analytical impact of moving from a gFOBT to a FIT bowel cancer screening programme.

METHODS

We interrogated data obtained in a FIT pilot carried out in England in 2014 to assess the timeliness of specimen collection device return time and analysis for gFOBT and FIT, the impact of time to analysis on faecal haemoglobin (f-Hb) concentration, and any differences observed between analyses carried out at two different testing laboratories.

RESULTS

FIT kits were returned on average 5.6 days sooner than gFOBT. The time to analysis for FIT leads to an overall rise in f-Hb concentration within the manufacturer's stated 14-day stability period.

CONCLUSION

Both these factors are important considerations for laboratories when considering setting up a bowel cancer screening programme, especially if transitioning from gFOBT to FIT. Our data also support previous evidence of males having a higher f-Hb than females and demonstrate that after adjusting for sex, age and screening hub, neither index of multiple deprivation nor screening episode significantly affected f-Hb.

Early colorectal cancer detection-Current and evolving challenges in evidence, guidelines, policy, and practices

The understanding at the beginning of the last century that colorectal cancer began as a localized disease that progressed and became systemic, and that most colorectal cancer arose from adenomatous polyps gave rise to aggressive attempts at curative treatment and eventually attempts to detect advanced lesions before they progressed to invasive disease. In the last four decades, steadily greater uptake of screening has led to reductions in colorectal cancer incidence and mortality. However, the fullest potential of screening is not being met due to the lack of organized screening, where a systems approach could lead to higher rates of screening of average and high risk groups, higher quality screening, and prompt followup of adults with positive screening tests. ABSTRACT: Since the beginning of the 20th century, there has been a general understanding that colorectal cancer is a clonal disease that progresses from a localized stage with a favorable prognosis through progressively more advanced stages which have progressively worse prognosis. That understanding led first to determined efforts to detect and treat early stage symptomatic disease, and then to detect pre-symptomatic colorectal cancer and precursor lesions, where there was hope that the natural history of the disease could be arrested and the incidence and premature mortality of colorectal cancer averted. Toward the end of the last century, guidelines for colorectal cancer screening, growth in the number of technical options for screening, and a steady increase in the proportion of the adult population who attended screening contributed to the beginning of a significant decline in colorectal cancer incidence and mortality. Despite this progress, colorectal cancer remains the third leading cause of death among men and women in the United States. Screening for early detection of precursor lesions and localized cancer offers the single most productive opportunity to further reduce the burden of disease, and yet nearly four in five deaths from colorectal cancer are associated with having never been screened, not recently screened, or not followed up for an abnormal screening test. This simple observation is a call to action in all communities to apply existing knowledge to fulfill the potential to prevent avertable incidence and mortality.

Feasibility of Methylated CLIP4 in Stool for Early Detection of Colorectal Cancer: A Training Study in Chinese Population

BACKGROUND

Early detection of colorectal cancer (CRC) and precancerous lesion is vitally important for mitigating CRC morbidity and mortality. Aberrant DNA methylations in certain promoter regions have been identified to be closely associated with CRC development and progression, suggesting their potential as diagnostic biomarkers for early detection. In this study, we evaluated the performance of methylated CLIP4 in stool specimens as a potential biomarker for CRC detection.

METHODS

A total of 321 subjects out of 365 enrolled participants were included in the final analysis, including 154 CRC patients, 23 advanced adenoma (AA) patients, 49 small polyp (SP) patients, and 95 healthy controls. CLIP4 methylation level was examined by qPCR with bisulfite converted DNA purified from approximately 5 g stool specimen.

RESULTS

Methylated CLIP4 test showed high sensitivities of 78.3% (95% CI: 55.8%-91.7%) and 90.3% (95% CI: 84.2%-94.3%) for detecting AA and CRC, respectively, with a specificity of 88.4% (95% CI: 79.8%-93.8%). CLIP4 methylation level discriminated AA and CRC patients from control subjects with area under the curve values of 0.892 (95% CI: 0.795-0.988) and 0.961 (95% CI: 0.938-0.983). Further analysis indicated no significant difference in sensitivities among different ages, genders, stages, locations, sides, tumor sizes and differentiation statuses.

CONCLUSIONS

Methylated CLIP4 showed a strong potential as a noninvasive biomarker for early CRC detection.

PPV and Detection Rate of mt-sDNA Testing, FIT, and CT Colonography for Advanced Neoplasia: A Hierarchic Bayesian Meta-Analysis of the Noninvasive Colorectal Screening Tests

BACKGROUND. Noninvasive tests for colorectal cancer (CRC) screening and prevention limit the need for invasive colonoscopy to follow up positive test results. However, the relative performance characteristics of available noninvasive tests have not yet been adequately compared. OBJECTIVE. We performed a systematic review and meta-analysis to compare the diagnostic performance of the available noninvasive CRC screening tests, including multitarget stool DNA (mt-sDNA) testing, fecal immunochemical testing (FIT), and CT colonography (CTC), with an emphasis on comparison of PPV and detection rate (DR) for advanced neoplasia (AN; encompassing cases of advanced adenomas and CRC). EVIDENCE ACQUISITION. After systematic searches of MEDLINE and Google Scholar databases, 10 mt-sDNA, 27 CTC, and 88 FIT published screening studies involving 25,132, 33,493, and 2,355,958 asymptomatic adults, respectively, were included. Meta-analysis with hierarchic Bayesian modeling was conducted in accordance with Cochrane Collaboration and PRISMA guidelines to determine test positivity rates (TPRs) leading to optical colonoscopy, as well as PPVs and DRs for both AN and CRC. Different positivity thresholds were considered for FIT and CTC. EVIDENCE SYNTHESIS. Point estimates (with 95% credible intervals) from pooled Bayesian meta-analysis combining all thresholds for FIT and stratifying CTC results by a polyp size threshold of 6 mm or larger (CTC6) and 10 mm or larger (CTC10) were calculated. TPR was 13.5% (10.9-16.6%) for mt-sDNA testing, 6.4% (5.8-7.2%) for FIT, 13.4% (11.4-15.6%) for CTC6, and 6.6% (5.2-7.7%) for CTC10. AN PPV was 26.9% (95% credible interval, 21.8-33.2%) for mt-sDNA testing, 31.8% (29.3-34.5%) for FIT, 34.4% (27.2-41.0%) for CTC6, and 61.0% (54.0-70.0%) for CTC10. CRC PPV was 2.4% (1.5-3.9%) for mt-sDNA testing, 4.9% (4.3-5.3%) for FIT, 3.5% (2.5-4.8%) for CTC6, and 6.0% (4.3-8.0%) for CTC10. The DR for AN was 3.4% (95% credible interval, 2.5-4.8%) for mt-SDNA, 2.0% (1.8-2.3%) for FIT, 4.8% (4.0-6.5%) for CTC6, and 4.0% (3.0-4.6%) for CTC10. When FIT is restricted to a lower threshold (< 10 μg Hb/g feces), its performance profile is similar to that of mt-sDNA testing, although available data are limited. AN PPV odds ratios (relative to CTC10 as the reference) were 0.24 (95% credible interval, 0.17-0.33) for mt-sDNA testing, 0.30 (0.24-0.45) for FIT, and 0.33 (0.25-0.47) for CTC6. CONCLUSION. Among noninvasive CRC screening tests, CTC with a polyp size threshold of 10 mm or larger most effectively targets AN, preserving detection while also decreasing unnecessary colonoscopies compared with mt-sDNA testing and FIT. CLINICAL IMPACT. CTC performed with a polyp size threshold for colonoscopy referral set at 10 mm or larger represents the most effective and efficient noninvasive screening test for CRC prevention and detection.

Precision Oncology, Signaling and Anticancer Agents in Cancer Therapeutics

BACKGROUND

The global alliance for genomics and healthcare facilities provides innovational solutions to expedite research and clinical practices for complex and incurable health conditions. Precision oncology is an emerging field explicitly tailored to facilitate cancer diagnosis, prevention and treatment based on patients' genetic profile. Advancements in "omics" techniques, next-generation sequencing, artificial intelligence and clinical trial designs provide a platform for assessing the efficacy and safety of combination therapies and diagnostic procedures.

METHOD

Data were collected from Pubmed and Google scholar using keywords: "Precision medicine", "precision medicine and cancer", "anticancer agents in precision medicine" and reviewed comprehensively.

RESULTS

Personalized therapeutics including immunotherapy, cancer vaccines, serve as a groundbreaking solution for cancer treatment. Herein, we take a measurable view of precision therapies and novel diagnostic approaches targeting cancer treatment. The contemporary applications of precision medicine have also been described along with various hurdles identified in the successful establishment of precision therapeutics.

CONCLUSION

This review highlights the key breakthroughs related to immunotherapies, targeted anticancer agents, and target interventions related to cancer signaling mechanisms. The success story of this field in context to drug resistance, safety, patient survival and in improving quality of life is yet to be elucidated. We conclude that, in the near future, the field of individualized treatments may truly revolutionize the nature of cancer patient care.

ACG Clinical Guidelines: Colorectal Cancer Screening 2021

Colorectal cancer (CRC) is the third most common cancer in men and women in the United States. CRC screening efforts are directed toward removal of adenomas and sessile serrated lesions and detection of early-stage CRC. The purpose of this article is to update the 2009 American College of Gastroenterology CRC screening guidelines. The guideline is framed around several key questions. We conducted a comprehensive literature search to include studies through October 2020. The inclusion criteria were studies of any design with men and women age 40 years and older. Detailed recommendations for CRC screening in average-risk individuals and those with a family history of CRC are discussed. We also provide recommendations on the role of aspirin for chemoprevention, quality indicators for colonoscopy, approaches to organized CRC screening and improving adherence to CRC screening. CRC screening must be optimized to allow effective and sustained reduction of CRC incidence and mortality. This can be accomplished by achieving high rates of adherence, quality monitoring and improvement, following evidence-based guidelines, and removing barriers through the spectrum of care from noninvasive screening tests to screening and diagnostic colonoscopy. The development of cost-effective, highly accurate, noninvasive modalities associated with improved overall adherence to the screening process is also a desirable goal.

Stool DNA test targeting methylated syndecan-2 (SDC2) as a noninvasive screening method for colorectal cancer

Despite the steadily increasing worldwide incidence of colorectal cancer (CRC), an effective noninvasive approach for early detection of CRC is still under investigation. The guaiac-based fecal occult blood test (FOBT) and fecal immunochemical test (FIT) have gained popularity as noninvasive CRC screening tests owing to their convenience and relatively low costs. However, the FOBT and FIT have limited sensitivity and specificity. To develop a noninvasive tool for the detection of CRC, we investigated the sensitivity, specificity, and accuracy of a stool DNA test targeting methylated syndecan-2 (SDC2), which is frequently methylated in patients with CRC. The present study enrolled 62 patients diagnosed as having stage 0-IV CRC and 76 healthy participants between July 2018 and June 2019 from two institutions. Approximately 4.5 g of stool sample was collected from each participant for detection of human methylated SDC2 gene. In total, 48 of 62 (77.4%) patients with CRC showed positive results, whereas 67 out of 76 (88.2%) healthy participants showed negative results. The area under the curve of the receiver operating characteristic curve constructed was 0.872 for discrimination between patients with CRC and healthy individuals. The present study highlights the potential of the fecal methylated SDC2 test as a noninvasive detection method for CRC screening with a relatively favorable sensitivity of 77.4%, a specificity of 88.2% and a positive predictive value of 84.2% compared with other available fecal tests. Further multicenter clinical trials comprising subjects of varied ethnicities are required to validate this test for the mass screening of patients with CRC.

DIAGNOSTIC ACCURACY OF ONE SAMPLE OR TWO SAMPLES QUANTITATIVE FECAL IMMUNOCHEMICAL TESTS FOR INTESTINAL NEOPLASIA DETECTION

BACKGROUND

Rectal bleeding is the most important symptom of intestinal neoplasia; thus, tests of occult blood detection in stools are widely used for pre neoplastic lesions and colorectal cancer (CRC) screening.

OBJECTIVE

Evaluate the accuracy of OC-Sensor quantitative test (Eiken Chemical, Tokyo, Japan) at cut-off 10 µg Hb/g feces (50 ng/mL) in a cohort of subjects that had to undergo diagnostic colonoscopy, and if more than one sample collected in consecutive days would improve the diagnostic accuracy of the test.

METHODS

Patients (mean age 56.3±9.7 years) that underwent colonoscopy prospectively randomly received one (1-sample FIT, FIT 1) or two (2-sample FIT, FIT 2) collection tubes. They collected the stool sample before starting colonoscopy preparation. Samples were analyzed by the OC-Auto Micro 80 (Eiken Chemical, Tokyo, Japan). The performance of FIT 1 and FIT 2 were compared to the colonoscopy findings.

RESULTS

Among 289 patients, CRC was diagnosed in 14 (4.8%), advanced adenoma in 37 (12.8%), early adenoma in 71 (24.6%) and no abnormalities in 141 (48.8%). For FIT 1, the sensitivity for CRC was 83.3% (95%CI 36.5-99.1%), for advanced adenoma was 24% (95%CI 10.1-45.5%), with specificity of 86.9% (95%CI 77.3-92.9%). For FIT 2, the sensitivity for CRC was 75% (95%CI 35.6-95.5%), for advanced adenoma was 50% (95%CI 22.3-77.7%), with specificity of 92.9% (95%CI 82.2-97.7%). The positive likelihood ratios were 1.8 (95%CI 0.7-4.4 for FIT 1) and 7.1 (95%CI 2.4-21.4 for FIT 2) for advanced adenoma, and 6.4 (95%CI 3.3-12.3, for FIT 1) and 10.7 (95%CI 3.8-29.8, for FIT 2) for CRC. The negative likelihood ratio were 0.9 (95%CI 0.7-1, for FIT 1) and 0.5 (95%CI 0.3-0.9, for FIT 2) for advanced adenoma, and 0.2 (0.03-1.1, for FIT 1) and 0.3 (0.08-0.9, for FIT 2) for CRC. The differences between FIT 1 and FIT 2 performances were not significant. However, the comparison of the levels of hemoglobin in feces of patients of FIT 1 and FIT 2 showed that the differences between no polyp group and advanced adenoma and CRC were significant.

CONCLUSION

The accuracy of OCR Sensor with 10 µg Hb/g feces cut-off was comparable to other reports and two-sample collection improved the detection rate of advanced adenoma, a pre neoplastic condition to prevent CRC incidence.

Pilot study of the effect of gastrointestinal diets on fecal occult blood testing in cats

OBJECTIVES

The aim of this study was to assess the methodology of guaiac-based fecal occult blood (FOB) testing in healthy cats, and to examine the effect of feeding selected gastrointestinal diets (canned and dry) on FOB results.

METHODS

Stool obtained from three cats was mixed with incremental quantities of EDTA whole blood. FOB tests were performed in triplicate and interpreted at 5 mins, and at 24, 48 and 72 h post-test set-up. Ten cats were fed their normal diets, a dry hydrolyzed protein diet, a dry gastrointestinal diet and then transitioned back to their normal diet over a 7-week period. A subsequent study was repeated with similar hydrolyzed protein and gastrointestinal canned diets. Two fecal samples were tested per cat each week using human point-of-care guaiac tests.

RESULTS

Ten microliters of whole feline blood could be reliably detected in feline stool at all time points evaluated. There was no evidence of an association between the dry hydrolyzed and dry gastrointestinal diets and a positive FOB test result (P = 0.33). Cats fed a canned gastrointestinal diet had a significantly higher probability of producing a positive FOB result than when on their normal diet (P <0.01). Feeding the canned hydrolyzed diet was not associated with an increased probability of a positive FOB test vs the normal diet (P = 0.94).

CONCLUSIONS AND RELEVANCE

Small amounts of blood in feline stool can be reliably and repeatedly detected as early as 5 mins post-FOB test set-up, making this a user-friendly bench-top screening test in a veterinary setting. Cats fed a single dry hydrolyzed, dry gastroenteric or canned hydrolyzed diet in this study had a low chance of false-positive FOB test results, while those fed the canned gastrointestinal diet had a significantly greater likelihood of producing false-positive results.

Diagnostic Value of Combinatorial Markers in Colorectal Carcinoma

Objectives: Blood-based tests have been shown to be an effective strategy for colorectal cancer (CRC) detection in screening programs. This study was aimed to test the performance of 20 blood markers including tumor antigens, inflammatory markers, and apolipoproteins as well as their combinations.

Methods: In total 203 healthy volunteers and 102 patients with CRC were enrolled into the study. Differences between healthy and cancer subjects were evaluated using Wilcoxon rank-sum test. Several multivariate classification algorithms were employed using information about different combinations of biomarkers altered in CRC patients as well as age and gender of the subjects; random sub-sampling cross-validation was done to overcome overfitting problem. Diagnostic performance of single biomarkers and multivariate classification models was evaluated by receiver operating characteristic (ROC) analysis.

Results: Of 20 biomarkers, 16 were significantly different between the groups (p-value ≤ 0.001); ApoA1, ApoA2 and ApoA4 levels were decreased, whereas levels of tumor antigens (e.g. carcinoembriogenic antigen) and inflammatory markers (e.g., C-reactive protein) were increased in CRC patients vs. healthy subjects. Combinatorial markers including information about all 16 significant analytes, age and gender of patients, demonstrated better performance over single biomarkers with average accuracy on test datasets ≥95% and area under ROC curve (AUROC) ≥98%.

Conclusions: Combinatorial approach was shown to be a valid strategy to improve performance of blood-based CRC diagnostics. Further evaluation of the proposed models in screening programs will be performed to gain a better understanding of their diagnostic value.

Making FIT Count: Maximizing Appropriate Use of the Fecal Immunochemical Test for Colorectal Cancer Screening Programs

Colorectal cancer (CRC) remains one of the most common and deadly malignancies despite advancements in screening, diagnostic capabilities, and treatment. The ability to detect and remove precancerous and cancerous lesions via screening has altered the epidemiology of the disease, decreasing incidence, mortality, and late-stage disease presentation. The fecal immunochemical test (FIT) is a screening test that aims to detect human hemoglobin in the stool. FIT is the most common CRC screening modality worldwide and second most common in the United States. Its use in screening programs has been shown to increase screening uptake and improve CRC outcomes. However, FIT-based screening programs vary widely in quality and effectiveness. In health systems with high-quality FIT screening programs, only superior FIT formats are used, providers order FIT appropriately, annual patient participation is high, and diagnostic follow-up after an abnormal result is achieved in a timely manner. Proper utilization of FIT involves multiple steps beyond provider recommendation of the test. In this commentary, we aim to highlight ongoing challenges in FIT screening and suggest interventions to maximize FIT effectiveness. Through active engagement of patients and providers, health systems can use FIT to help optimize CRC screening rates and improve CRC outcomes.

Utilisation of Colorectal Cancer Screening Tests in European Countries by Type of Screening Offer: Results from the European Health Interview Survey

In the past two decades, an extensive rollout of colorectal cancer (CRC) screening programmes has been initiated in European countries with a large heterogeneity of screening offers. Using data from a population-based cross-sectional survey conducted between 2013 and 2016 in all European Union countries, we analysed the utilisation of faecal tests and colonoscopy among people aged 50–74 years and the factors associated with uptake by type of screening offer. We observed the highest utilisation of either test for countries with fully rolled out organised programmes with faecal tests (ranging from 29.7% in Croatia to 66.7% in the UK) and countries offering both faecal tests and colonoscopy (from 22.7% in Greece to 70.9% in Germany). Utilisation was very low for countries with no programme (from 6.3% in Romania to 30.5% in Norway). Younger age (50–54 years), longer time since last consultation with a doctor and a lifestyle score associated with increased CRC risk were significantly associated with lower test use, a pattern observed across all types of screening offers. Our results suggest that more countries should implement organised programmes with faecal immunochemical tests, in combination with alternative endoscopy offers where resources allow. Furthermore, there is a large potential for increasing screening use in Europe by better reaching the younger eligible individuals, those who have not been to the doctor recently and those at increased risk for CRC.

Impact of Social Support on Colorectal Cancer Screening among Adult Hispanics/Latinos: A Randomized Community-based Study in Central Pennsylvania

In the United States, the five-year survival rate of colorectal cancer for Latinos is lower than it is for White, non-Latinos. Differences in survival are due, in part, to Latinos being diagnosed at a later stage. An ethnic gap in the use of colorectal cancer screening contributes to the difference in survival. We developed, implemented, and evaluated a targeted colorectal cancer screening intervention to increase colorectal cancer screening uptake by sex, ethnicity, and geography. We measured actual colorectal cancer screening uptake in both arms as a method to determine completion rates. We used a randomized, community-based, participatory design to test the impact of social support (intervention) on completion of a provider-recommended, take-home fecal immunochemical test (FIT) kit screening test among average-risk, urban, and rural Pennsylvania Latino adults age 50 and older not currently adherent to national colorectal cancer screening guidelines (n = 264). Participants in each arm attended a community-based educational program offered at eight sites. Among the 264 participants, 154 (58%) returned a completed usable FIT kit screening test. A higher return rate was observed among participants in the social support arm (66.0%) compared with the control (47.2%). Participants in the social support arm were statistically significant 2.67 times as likely to return a completed FIT kit. Of these, 27 (17.5%) had a positive FIT kit screening test result. The results of this study suggest that social support is an effective method to increase colorectal cancer screening rates among Latinos. Future studies should examine dissemination and implementation of community-based strategies among Latinos that include social support.

Effect of Sex, Age, and Positivity Threshold on Fecal Immunochemical Test Accuracy: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Quantitative fecal immunochemical tests (FITs) for hemoglobin are commonly used for colorectal cancer (CRC) screening. We aimed to quantify the change in CRC and advanced adenoma detection and number of positive test results at different positivity thresholds and by sex and age.

METHODS

We searched MEDLINE and EMBASE, selecting articles of FIT for CRC detection in asymptomatic adults undergoing screening. We calculated sensitivity and specificity, as well as detected number of cancers, advanced adenomas, and positive test results at positivity thresholds ≤10 μg hemoglobin/g feces, 10 to ≤20 μg/g, 20 to ≤30 μg/g, and >30 μg/g. We also analyzed results from stratified by patient sex, age, and reference standard.

RESULTS

Our meta-analysis comprised 46 studies with 2.4 million participants and 6478 detected cancers. Sensitivity for detection of CRC increased from 69% (95% confidence interval [CI], 63%-75%) at thresholds >10 μg/g and ≤20 μg/g to 80% (95% CI, 76%-83%) at thresholds ≤10 μg/g. At these threshold values, sensitivity for detection of advanced adenomas increased from 21% (95% CI, 18%-25%) to 31% (95% CI, 27%-35%), whereas specificity decreased from 94% (95% CI, 93%-96%) to 91% (95% CI, 89%-93%). In 3 studies stratified by sex, sensitivity of CRC detection was 77% in men (95% CI, 75%-79%) and 81% in women (95% CI, 60%-100%) (P = .68). In 3 studies stratified by age groups, sensitivity of CRC detection was 85% for ages 50-59 years (95% CI, 71%-99%) and 73% for ages 60-69 years (95% CI, 71%-75%) (P = .10). All studies with colonoscopy follow-up had similar sensitivity levels for detection of CRC to studies that analyzed 2-year registry follow-up data (74%; 95% CI, 68%-78% vs 75%; 95% CI, 73%-77%).

CONCLUSIONS

In a meta-analysis of studies that analyzed detection of CRC and advanced adenomas at different FIT positivity thresholds, we found the sensitivity and specificity of detection to vary with positive cutoff value. It might be possible to decrease positive threshold values for centers with sufficient follow-up colonoscopy resources. More research is needed to precisely establish FIT thresholds for each sex and age subgroup.

PROTOCOL

PROSPERO CRD42017068760.

Colorectal carcinoma screening: Established methods and emerging technology

Colorectal carcinoma screening programs have shown success in lowering both the incidence and mortality rate of colorectal carcinoma at a population level, in part because this carcinoma is relatively slow growing and has an identifiable premalignant lesion. Still, many patients do not undergo the recommended screening for colorectal carcinoma, and of those who do, a subset may be over- or under-diagnosed by the currently available testing methods. The primary purpose of this article is to review the data regarding currently available colorectal cancer screening modalities, which include fecal occult blood testing, direct colonic visualization, and noninvasive imaging techniques. In addition, readers will be introduced to a variety of biomarkers that may serve as stand-alone or adjunct tests in the future. Finally, there is a brief discussion of the current epidemiologic considerations that public health officials must address as they create population screening guidelines. The data we provide as laboratory physicians and scientists are critical to the construction of appropriate recommendations that ultimately decrease the burden of disease from colorectal carcinoma.

Colorectal cancer screening with faecal immunochemical testing, sigmoidoscopy or colonoscopy: a microsimulation modelling study

OBJECTIVE

To estimate benefits and harms of different colorectal cancer screening strategies, stratified by (baseline) 15-year colorectal cancer risk.

DESIGN

Microsimulation modelling study using MIcrosimulation SCreening ANalysis-Colon (MISCAN-Colon).

SETTING

A parallel guideline committee (BMJ Rapid Recommendations) defined the time frame and screening interventions, including selection of outcome measures.

POPULATION

Norwegian men and women aged 50-79 years with varying 15-year colorectal cancer risk (1-7%).

COMPARISONS

Four screening strategies were compared with no screening: biennial or annual faecal immunochemical test (FIT) or single sigmoidoscopy or colonoscopy at 100% adherence.

MAIN OUTCOME MEASURES

Colorectal cancer mortality and incidence, burdens, and harms over 15 years of follow-up. The certainty of the evidence was assessed using the GRADE approach.

RESULTS

Over 15 years of follow-up, screening individuals aged 50-79 at 3% risk of colorectal cancer with annual FIT or single colonoscopy reduced colorectal cancer mortality by 6 per 1000 individuals. Single sigmoidoscopy and biennial FIT reduced it by 5 per 1000 individuals. Colonoscopy, sigmoidoscopy, and annual FIT reduced colorectal cancer incidence by 10, 8, and 4 per 1000 individuals, respectively. The estimated incidence reduction for biennial FIT was 1 per 1000 individuals. Serious harms were estimated to be between 3 per 1000 (biennial FIT) and 5 per 1000 individuals (colonoscopy); harms increased with older age. The absolute benefits of screening increased with increasing colorectal cancer risk, while harms were less affected by baseline risk. Results were sensitive to the setting defined by the guideline panel. Because of uncertainty associated with modelling assumptions, we applied a GRADE rating of low certainty evidence to all estimates.

CONCLUSIONS

Over a 15 year period, all screening strategies may reduce colorectal cancer mortality to a similar extent. Colonoscopy and sigmoidoscopy may also reduce colorectal cancer incidence, while FIT shows a smaller incidence reduction. Harms are rare and of similar magnitude for all screening strategies.

Diagnostic colonoscopy completion after abnormal fecal immunochemical testing and quality of tests used at 8 Federally Qualified Health Centers in Southern California: Opportunities for improving screening outcomes

BACKGROUND

The effectiveness of colorectal cancer screening with fecal immunochemical tests (FITs) of stool blood depends on high rates of colonoscopy follow-up for abnormal FITs and the use of high-quality tests. This study characterized colonoscopy referral and completion among patients with abnormal FITs and the types of FITs implemented in a sample of Southern California Federally Qualified Health Centers (FQHCs).

METHODS

FQHCs in San Diego, Imperial, and Los Angeles Counties were invited to define a cohort of ≥150 consecutive patients with abnormal FITs in 2015-2016 and to provide data on sex, insurance status, diagnostic colonoscopy referrals and completion within 6 months of abnormal FITs, and the types (brands) of FITs implemented. The primary outcomes were the proportions with colonoscopy referrals and completion for all patients at each FQHC and in aggregate.

RESULTS

Eight FQHCs provided data for 1229 patients with abnormal FITs; 46% were male, and 20% were uninsured. Among patients with abnormal FITs, 89% (1091 of 1229; 95% confidence interval [CI], 0.87-0.91) had a colonoscopy referral, and 44% (539 of 1229; 95% CI, 0.41-0.47) had colonoscopy completion. Across FQHCs, the range for colonoscopy referral was 73% to 96%, and the range for completion was 18% to 57%. Six of the 8 FQHCs (75%) reported FIT brands with limited data to support their effectiveness.

CONCLUSIONS

In a sample of Southern California FQHCs, diagnostic colonoscopy completion after abnormal FITs was substantially below the nationally recommended benchmark to achieve 80% completion, and the use of FIT brands with limited data to support their effectiveness was high. These findings suggest a need for policies and multilevel interventions to promote diagnostic colonoscopy among individuals with abnormal FITs and the use of higher quality FITs.

Low Literacy Level Instructions and Reminder Calls Improve Patient Handling of Fecal Immunochemical Test Samples

BACKGROUND & AIMS

The fecal immunochemical test (FIT) is an alternative to colonoscopy and can increase overall screening for colorectal cancer (CRC). However, little is known about the frequency of and reasons for mishandled FIT samples.

METHODS

We performed a prospective study, nested within a randomized controlled trial of patients, recruited from December 2015 through August 2017, who were not up to date with colorectal cancer screening (50-75 years old). The patients were randomly assigned to usual care or outreach groups that received a mailed FIT with low literacy level instructions or a reminder call, or both. We examined frequency of and reasons for mishandled FIT samples, including absence of collection date; time from collection to laboratory receipt of more than 14 days; or mishandling of stool, buffer, or cap. The outcomes were the frequency of mishandled FIT samples, effects of outreach on mishandling, and positive results from the FIT among proper and mishandled samples.

RESULTS

FIT samples were returned from 1871 patients assigned to usual care and 3045 who received the low literacy level instructions and a reminder call. In total, 19.8% of samples were mishandled; most of these (93.7%) had not labeled the date of stool collection but were still processed. Of the received samples, 1.2% of were not processed because the time from patient collection to laboratory receipt was more than 14 days. Outreach was associated with a lower proportion of mishandled samples (16.5% vs 25.0% for usual care; P < .0001). The proportion of mishandled samples was lowest among patients who received the low literacy level instruction and a reminder call (12.8%, P < .0001). There was no significant difference in proportions of positive results between properly processed samples (7.5%) and improperly processed samples (6.2%) (P = .14).

CONCLUSION

In a prospective study of patients who were not up to date with colorectal cancer screening, we found that almost 20% of FIT samples were mishandled, with most patients missing the stool collection date. Patient outreach was associated with a lower proportion of mishandled samples, but there was no difference in proportions of positive results between properly and improperly handled samples. Our findings indicate that routine processing of undated FIT samples is associated with similar rates of positive results. There are limited data on test characteristics for FIT samples beyond the 14 days of stool acquisition. The inclusion of low literacy level instructions with reminder calls was associated with improved patient handling of the FIT sample. ClincialTrials.gov no: NCT02613260.

The Rise of Colorectal Cancer in Asia: Epidemiology, Screening, and Management

PURPOSE OF REVIEW

Colorectal cancer (CRC) remains the third most commonly diagnosed cancer globally, and its incidence and mortality rates have been on the rise in Asia. In this paper, we summarize the recent trends and screening challenges of CRC in this region.

RECENT FINDINGS

In 2018, Asia had the highest proportions of both incident (51.8%) and mortality (52.4%) CRC cases (all genders and ages) per 100,000 population in the world. In addition, there has been a rising trend of this disease across Asia with some regional geographic variations. This rise in CRC can be attributed to westernized dietary lifestyle, increasing population aging, smoking, physical inactivity, and other risk factors. In curbing the rising trend, Japan, South Korea, Singapore, and Taiwan have launched nationwide population-based screening programs. CRC screening across this region has been found to be effective and cost-effective compared with no screening at all. The emergence of new therapies has caused a reduction in case fatality; however, these new options have had a limited impact on cure rates and long-term survival due to the great disparity in treatment capacity/resources and screening infrastructures among Asian countries with different degrees of economic development. CRC is still rising in Asia, and implementation of screening is necessary for moderate- to high-incidence countries and construction of treatment capacity is the priority task in low-incidence and low-income countries. Unless countries in Asia implement CRC screening, the incidence and mortality rates of this disease will continue to rise especially with the rapidly rising population growth, economic development, westernized lifestyle, and increasing aging.

Reduction of faecal immunochemical test false-positive results using a signature based on faecal bacterial markers

BACKGROUND

Colorectal cancer is the second commonest cause of cancer mortality. Some countries are implementing colorectal cancer screening to detect lesions at an early stage using non-invasive tools like the faecal immunochemical test. Despite affordability, this test shows a low sensitivity for precancerous lesions and a low positive predictive value for colorectal cancer, resulting in a high false-positive rate.

AIM

To develop a new, non-invasive colorectal cancer screening tool based on bacterial faecal biomarkers, which in combination with the faecal immunochemical test, could allow a reduction in the false-positive rate. This tool is called risk assessment of intestinal disease for colorectal cancer (RAID-CRC).

METHODS

We performed both the faecal immunochemical test and the bacterial markers analysis (RAID-CRC test) in stool samples from individuals with normal colonoscopy (167), non-advanced adenomas (88), advanced adenomas (30) and colorectal cancer (48). All the participants showed colorectal cancer-associated symptoms.

RESULTS

Performance of the faecal immunochemical test for advanced neoplasia (ie advanced adenoma and colorectal cancer) was determined by using the cut-off value established in Catalonia (20 µg haemoglobin/g of faeces) for a population-based screening approach. Sensitivity and specificity values of 83% and 80%, respectively, and positive and negative predictive values of 56% and 94%, respectively, were obtained. When both the immunological and the biological analysis were combined, the corresponding values were 80% and 90% for sensitivity and specificity, respectively, and 70% and 94% for positive and negative predictive values, respectively, resulting in a 50% reduction of the false-positive rate.

CONCLUSIONS

RAID-CRC test allows a substantial reduction in the faecal immunochemical test false-positive results (50%) in a symptomatic population. Further validation is indicated in a colorectal cancer-screening scenario.

Diagnostic Accuracy of FOBT and Colorectal Cancer Genetic Testing: A Systematic Review & Meta-Analysis

Introduction:

Colorectal cancer (CRC) is the second leading cause of cancer related death in the world after lung cancer. Early detection of CRC leads to improvement in cancer survival rate. In recent years, efforts have been made to discover a non-invasive screening marker of higher sensitivity and specificity. Fecal occult blood testing (FOBT) and genetic testing become alternative modalities to screen CRC in the population other than colonoscopy. The aim of this systematic review and meta-analysis is to determine the diagnostic accuracy, sensitivity and specificity of FOBT and genetic testing as screening tools in colorectal cancer.

Methods:

A literature search of PubMed, ScienceDirect, and Scopus was carried out. The search strategy was restricted to human subjects and studies are published in English. Data on sensitivity and specificity were extracted and pooled. Heterogeneity was assumed at significance level of p < 0.10 and was tested by chi squared. Degree of heterogeneity was quantified using the I² statistic, and values of less than 25% is considered as homogenous. All analyses were performed using the software Meta-Disc.

Results:

A total of eleven studies were suitable for data synthesis and analysis. Five studies were analyzed for the accuracy of genetic testing, the pooled estimate for sensitivity and specificity were 71% (95% CI: 66, 75%) and 95% (95% CI: 93, 97%) respectively. Another group of studies which had been evaluated for the accuracy of FOBT, the pooled sensitivity was 31% (95% CI: 25, 38%) while the pooled specificity was 87% (95% CI: 86, 89%).

Conclusions:

FOBTs is recommended to use as population-based screening tools for colorectal cancer while genetic testing should be focusing on patients with moderate and high risk individuals.

Performance Characteristics of Fecal Immunochemical Tests for Colorectal Cancer and Advanced Adenomatous Polyps: A Systematic Review and Meta-analysis

BACKGROUND

Studies report inconsistent performance of fecal immunochemical tests (FITs) for colorectal cancer (CRC) and advanced adenomas.

PURPOSE

To summarize performance characteristics of FITs for CRC and advanced adenomas in average-risk persons undergoing screening colonoscopy (reference standard) and to identify factors affecting these characteristics.

DATA SOURCES

Ovid MEDLINE, PubMed, Embase, and the Cochrane Library from inception through October 2018; reference lists of studies and reviews.

STUDY SELECTION

Two reviewers independently screened records to identify published English-language prospective or retrospective observational studies that evaluated FIT sensitivity and specificity for colonoscopic findings in asymptomatic, average-risk adults.

DATA EXTRACTION

Two authors independently extracted data and evaluated study quality.

DATA SYNTHESIS

Thirty-one studies (120 255 participants; 18 FITs) were included; all were judged to have low to moderate risk of bias. Performance characteristics depended on the threshold for a positive result. A threshold of 10 µg/g resulted in sensitivity of 0.91 (95% CI, 0.84 to 0.95) and a negative likelihood ratio of 0.10 (CI, 0.06 to 0.19) for CRC, whereas a threshold of greater than 20 µg/g resulted in specificity of 0.95 (CI, 0.94 to 0.96) and a positive likelihood ratio of 15.49 (CI, 9.82 to 22.39). For advanced adenomas, sensitivity was 0.40 (CI, 0.33 to 0.47) and the negative likelihood ratio was 0.67 (CI, 0.57 to 0.78) at 10 µg/g, and specificity was 0.95 (CI, 0.94 to 0.96) and the positive likelihood ratio was 5.86 (CI, 3.77 to 8.97) at greater than 20 µg/g. Studies had low to high heterogeneity, depending on the threshold. Although several FITs had adequate performance, sensitivity and specificity for CRC for 1 qualitative FIT were 0.90 and 0.91, respectively, at its single threshold of 10 µg/g; positive and negative likelihood ratios were 10.13 and 0.11, respectively. Comparison of 3 FITs at 3 thresholds was inconclusive: CIs overlapped, and the comparisons were across rather than within studies.

LIMITATIONS

Only English-language studies were included. Incomplete reporting limited quality assessment of some evidence. Performance characteristics are for 1-time rather than serial testing.

CONCLUSION

Single-application FITs have moderate to high sensitivity and specificity for CRC, depending on the positivity threshold. Sensitivity of 1-time testing for advanced adenomas is low, regardless of the threshold.

PRIMARY FUNDING SOURCE

Department of Medicine, Indiana University School of Medicine.

Fecal Fusobacterium nucleatum for the diagnosis of colorectal tumor: A systematic review and meta-analysis

The fecal Fusobacterium nucleatum has been reported as a potential noninvasive biomarker for colorectal tumor in several studies, but its exact diagnostic accuracy was ambiguous due to the wide range of sensitivity and specificity. To assess the diagnostic accuracy of fecal F. nucleatum for colorectal tumor, we searched electronic databases including PubMed, Cochrane Library, Embase, and Web of Science, without any date and language restrictions. Two reviewers independently extracted data and appraised study quality with Quality Assessment of Diagnostic Accuracy Studies. We included ten studies comprising 13 cohorts for colorectal cancer (CRC) and seven cohorts for colorectal adenoma (CRA). A total of 1450 patients and 1421 controls for CRC and 656 patients and 827 controls for CRA were included. The pooled sensitivity and specificity of fecal F. nucleatum for CRC were 71% (95% CI, 61%‐79%) and 76% (95% CI, 66%‐84%), with the area under the receiver‐operating characteristics (AUC) curve of 0.80 (95% CI, 0.76‐0.83). The pooled sensitivity and specificity of fecal F. nucleatum for CRA were 36% (95% CI, 27%‐46%) and 73% (95% CI, 65%‐79%), with an AUC of 0.60 (95% CI, 0.56‐0.65). Substantial heterogeneity among studies existed, which was partly caused by DNA extraction kits, regions of study, sample size, and demographic characteristics of participants. Fecal F. nucleatum was valuable for the diagnosis of CRC although it performed below expectation. For CRA, the specificity of fecal F. nucleatum indicated the possibility of noninvasive screening. Subgroup analyses for adenoma were incomplete due to lack of data. Heterogeneity limited the credibility of the study.

Faecal immunochemical testing implementation to increase colorectal cancer screening in primary care

Colorectal cancer (CRC) is the second leading cause of cancer death in USA, and CRC screening remains suboptimal. The aim of this quality improvement was to increase CRC screening in the internal medicine clinic (IMC) patients, between the ages of 50–75 years, from a baseline rate of 50%–70% over 12 months with the introduction of faecal immunochemical test (FIT) testing. We used the Plan–Do–Study–Act (PDSA) method and performed a root cause analysis to identify barriers to acceptance of CRC screening. The quality improvement team created a driver diagram to identify and prioritise change ideas. We developed a process flow map to optimise opportunities to improve CRC screening. We performed eight PDSA cycles. The major components of interventions included: (1) leveraging health information technology; (2) optimising team work, (3) education to patient, physicians and IMC staff, (4) use of patient navigator for tracking FIT completion and (5) interactive workshops for the staff and physicians to learn motivational interview techniques. The outcome measure included CRC screening rates with either FIT or colonoscopy. The process measures included FIT order and completion rates. Data were analysed using a statistical process control and run charts. Four hundred and seven patients visiting the IMC were offered FIT, and 252 (62%) completed the test. Twenty-two (8.7%) of patients were FIT positive, 14 of those (63.6%) underwent a subsequent diagnostic colonoscopy. We achieved 75% CRC screening with FIT or colonoscopy within 12 months and exceeded our goal. Successful strategies included engaging the leadership, the front-line staff and a highly effective multidisciplinary team. For average-risk patients, FIT was the preferred method of screening. We were able to sustain a CRC screening rate of 75% during the 6-month postproject period. Sustainable annual FIT is required for successful CRC screening.

Accuracy of a fecal immunochemical test according to outside temperature and travel time

Background

Fecal immunochemical tests (FITs) are widely used and recommended for colorectal cancer (CRC) screening. Fecal hemoglobin (Hb) may degrade with long transport durations and high ambient temperatures, potentially reducing sensitivity to detect CRC and its precursors. This study aimed at investigating the impact of temperatures and sample travel times on diagnostic performance of a quantitative FIT for detection of advanced neoplasms (AN, CRC, or advanced adenoma).

Methods

Participants of screening colonoscopy in south-western Germany conducted a quantitative FIT prior to bowel preparation between February 2012 and June 2016. From available locations and dates of stool sampling and transport, maximum ambient temperatures were linked to 2,870 participants aged 50–79 years and sample return durations were recorded. The impact of ambient temperatures and return duration on FIT sensitivity and specificity was assessed for five different cutoffs between 10 and 25 µg Hb/g feces.

Results

At a positivity threshold of 20 µg Hb/g feces, overall sensitivity and specificity for detecting any AN were 40% (95% CI, 35–47%) and 95% (95% CI, 94–96%), respectively. Inverse associations between maximum ambient temperature (median 18.1°C, inter-quartile range [IQR] =11.4–24.9°C) and sensitivity of FIT were observed which were stronger at higher cutoffs. Sample return durations (median 6 days, IQR =4–8 days) were not associated with variable sensitivities or specificities.

Conclusion

Hb degredation during fecal sample transportation in summer months may be of some concern for diagnostic performance of the FIT evaluated under routine conditions in a middle-European climate.

Interval colorectal cancer rates after Hemoccult Sensa and survival by detection mode for individuals diagnosed with colorectal cancer in Winnipeg, Manitoba

Objective

To assess the performance of the Sensa fecal occult blood test (FOBT) in a population-based screening program.

Setting

Manitoba, Canada.

Methods

This historical cohort study included individuals 52 to 74 years of age diagnosed with colorectal cancer (CRC) from 2008 to 2013. CRCs were categorized by detection following a screening program FOBT (Sensa), non-program FOBT (non-Sensa), or no FOBT. Screening program CRCs were classified as program-detected, interval program, or non-compliant. Logistic regression was used to compare characteristics by detection mode. Cox regression adjusted for lead-time was used to examine the effect of detection mode on survival.

Results

1,498 individuals were diagnosed with CRC; 132 (8.8%) had a screening program FOBT, 626 (41.8%) had a non-program FOBT, and 740 (49.4%) had no FOBT. Of the screening program FOBT CRCs, 72 were program-detected (54.5%), 42 were interval program (31.8%), and 18 were non-compliant (13.6%). Sensa interval cancer rate was 37.4% and sensitivity was 63.1% (95% Confidence Interval (CI): 54.3%-72.0%). The risk of death for individuals that had a non-program (Hazard ratio (HR) = 0.57, 95% CI:0.44–0.75) or a screening program FOBT (HR = 0.55, 95% CI:0.31–0.97) was lower than no FOBT. There was no significant difference in the risk of death for interval, non-compliant, and non-program CRCs compared to program-detected CRCs. Adjusting for lead time bias, sex, income quintile, tumour location, and age at diagnosis did not appreciably change the risk estimates.

Conclusion

More than one-third of CRCs may not be detected by Sensa. There may be no difference in survival between CRC detected by Sensa and non-Sensa FOBTs.

Positive predictive values of fecal immunochemical tests used in the STOP CRC pragmatic trial

Annual fecal immunochemical testing (FIT) is cost-effective for colorectal cancer (CRC) screening. However, FIT positivity rates and positive predictive value (PPV) can vary substantially, with false-positive (FP) results adding to colonoscopy burden without improving cancer detection. Our objective was to describe FIT PPV and the factors associated with FP results among patients undergoing CRC screening. In an ongoing pragmatic clinical trial of mailed-FIT outreach, clinics delivered one of three FIT brands (InSure, OC-Micro, and Hemosure). Patients who had a positive FIT result and a follow-up colonoscopy were included in this analysis (N = 1130). Patients' demographic and medical histories were abstracted from electronic health records (EHR). Associations with a FP result (ie, a positive FIT result with no evidence of advanced neoplasia during follow-up colonoscopy) were evaluated for FIT brand and patient factors using mixed-effects multivariable logistic regression. The mean proportion of FIT-positive results ranged from 8% in centers using the OC-Micro test to 21% for Hemosure. PPVs for advanced neoplasia were 0.30 to 0.17, respectively (P for χ2  = 0.08). In multivariable-adjusted models, use of Hemosure was associated with greater odds of a FP result than OC-Micro (OR = 2.00, 95% CI: 0.47-8.56) or InSure (OR = 1.72, 95% CI: 0.44-6.68). However, only female sex (OR = 1.58, 95% CI: 1.19-2.10) and history of a colorectal condition (OR = 2.17, 95% CI: 1.13-4.15) were significantly associated with FP. In conclusion, FIT positivity varied by brand, and FP results differed by patient factors available through the EHR. These results can be used to minimize the frequency of FP results, reducing patient distress and colonoscopy burden.

A taxonomic signature of obesity in a large study of American adults

Animal models suggest that gut microbiota contribute to obesity; however, a consistent taxonomic signature of obesity has yet to be identified in humans. We examined whether a taxonomic signature of obesity is present across two independent study populations. We assessed gut microbiome from stool for 599 adults, by 16S rRNA gene sequencing. We compared gut microbiome diversity, overall composition, and individual taxon abundance for obese (BMI ≥ 30 kg/m2), overweight (25 ≤ BMI < 30), and healthy-weight participants (18.5 ≤ BMI < 25). We found that gut species richness was reduced (p = 0.04), and overall composition altered (p = 0.04), in obese (but not overweight) compared to healthy-weight participants. Obesity was characterized by increased abundance of class Bacilli and its families Streptococcaceae and Lactobacillaceae, and decreased abundance of several groups within class Clostridia, including Christensenellaceae, Clostridiaceae, and Dehalobacteriaceae (q < 0.05). These findings were consistent across two independent study populations. When random forest models were trained on one population and tested on the other as well as a previously published dataset, accuracy of obesity prediction was good (~70%). Our large study identified a strong and consistent taxonomic signature of obesity. Though our study is cross-sectional and causality cannot be determined, identification of microbes associated with obesity can potentially provide targets for obesity prevention and treatment.