Faecal haemoglobin can define risk of colorectal neoplasia at surveillance colonoscopy in patients at increased risk of colorectal cancer

The value of hypersensitivity quantitative fecal immunochemical test in early colorectal cancer detection

At present, both the incidence and mortality rates of colorectal cancer are on the rise, making early screening a crucial tool in reducing the fatality rate. Although colonoscopy is the recommended method according to the guidelines, compliance tends to be poor. The fecal immunochemical test (FIT), a new technology that uses latex immunoturbidimetry to detect fecal blood, offers high specificity and sensitivity. Additionally, it is low-cost, easy to operate, and less likely to be affected by food and drugs, thus improving the compliance rate for population screening. Compared to other screening techniques, FIT represents a safer and more accurate option. This article reviews the application of FIT in early colorectal cancer screening.

FIT for purpose: study protocol for a randomized controlled trial to personalize surveillance colonoscopy for individuals at elevated risk of colorectal cancer

PURPOSE

There is increasing demand for colorectal cancer (CRC) surveillance, but healthcare capacity is limited. The burden on colonoscopy resources could be reduced by personalizing surveillance frequency using the fecal immunochemical test (FIT). This study will determine the safety, cost-effectiveness, and patient acceptance of using FIT to extend surveillance colonoscopy intervals for individuals at elevated risk of CRC.

METHODS

This multicenter, prospective, randomized controlled trial will invite participants who are scheduled for surveillance colonoscopy (due to a personal history of adenomas or a family history of CRC) and who have returned a low fecal hemoglobin (< 2 μg Hb/g feces; F-Hb) using a two-sample FIT (OC Sensor, Eiken Chemical Company) in the prior 3 years. A total of 1344 individuals will be randomized to either surveillance colonoscopy as scheduled or delayed by 1 or 2 years for individuals originally recommended a 3- or 5-year surveillance interval, respectively. The primary endpoint is incidence of advanced neoplasia (advanced adenoma and/or CRC). Secondary endpoints include cost-effectiveness and consumer acceptability of extending surveillance intervals, determined using surveys and discrete choice experiments.

CONCLUSION

This study will establish the safety, cost-effectiveness, and acceptability of utilizing a low FIT Hb result to extend colonoscopy surveillance intervals in a cohort at elevated risk for CRC. This personalized approach to CRC surveillance will lead to a reduction in unnecessary colonoscopies, increases in healthcare savings, and a better patient experience.  TRIAL REGISTRATION: Registration was approved on December 9, 2019 with the Australian New Zealand Clinical Trials Registry ANZCTR 12619001743156.

Faecal immunochemical testing reduces demand and improves yield of Leicester's 2-week pathway for change in bowel habit

AIM

We look at the effect of introducing the faecal immunochemical test (FIT) in the straight-to-test 2-week pathway for change in bowel habit (CIBH).

METHOD

The FIT in primary care triages 2-week wait (2WW) colorectal referrals for patients aged 60 years and above for straight-to-test CT colonography (CTC). We compare the impact of the FIT on numbers of 2WW CTCs, in the year before and after FIT, in both colorectal cancer (CRC) detection and cost-effectiveness at both 4 μg Hb/g faeces and 10 μg Hb/g faeces.

RESULTS

At a threshold of 4 μg Hb/g faeces, the positive predictive value of the FIT for diagnosis of CRC is 5.0% with a negative predictive value of 99.8% and a polyp detection rate of 25.5%. The introduction of the FIT resulted in a reduction in the number of CTCs performed through the CIBH pathway from a mean of 143.9 per month prior to the FIT to 66.8 CTCs per month once the FIT was well established. Given a FIT threshold of 10 μg Hb/g the number of CTCs would be predicted to fall by 70.4% to 42.6 CTCs per month resulting in higher CRC and polyp detection rate, and an estimated annual cost saving of £238 258 in our institution.

CONCLUSION

The FIT use in primary care improves the yield of 2WW referrals for CIBH alone and reduces the burden and cost of investigations to exclude CRC. Improvements may be possible by increasing the cut-off employed, without adversely affecting the risk of missing a cancer.

A comparison of the faecal haemoglobin concentrations and diagnostic accuracy in patients suspected with colorectal cancer and serious bowel disease as reported on four different faecal immunochemical test systems

OBJECTIVES

Faecal immunochemical tests for haemoglobin (FIT) are used in colorectal cancer (CRC) screening programmes and to triage patients presenting with symptoms suggestive of CRC for further bowel investigations. There are a number of quantitative FIT analytical systems available. Currently, there is no harmonisation or standardisation of FIT methods. The aim of the study was to assess the comparability of numerical faecal haemoglobin concentrations (f-Hb) obtained with four quantitative FIT systems and the diagnostic accuracy at different f-Hb thresholds.

METHODS

A subgroup of the National Institute for Health and Care Excellence (NICE) FIT study, a multicentre, prospective diagnostic accuracy study were sent four FIT specimen collection devices from four different FIT systems or two FIT devices for one FIT system. Faecal samples were examined and analysis of results carried out to assess difference between methods at thresholds of limit of detection (LoD), 10 µg haemoglobin/g faeces (µg/g) and 100 μg/g.

RESULTS

233 patients returned specimen collection devices for examination on four different systems; 189 patients returned two FIT kits for one system. At a threshold of 100 μg/g the sensitivity is the same for all methods. At lower thresholds of LoD and 10 μg/g differences were observed between systems in terms of patients who would be referred and diagnostic accuracies.

CONCLUSIONS

The lack of standardisation or harmonisation of FIT means that differences are observed in f-Hb generated on different systems. Further work is required to understand the clinical impact of these differences and to minimise them.

Systematic review: non-endoscopic surveillance for colorectal neoplasia in individuals with Lynch syndrome

BACKGROUND

Individuals with Lynch syndrome are at high risk for colorectal cancer (CRC). Regular colonoscopies have proven to decrease CRC incidence and mortality. However, colonoscopy is burdensome and interval CRCs still occur. Hence, an accurate, less-invasive screening method that guides the timing of colonoscopy would be of important value.

AIM

To outline the performance of non-endoscopic screening modalities for Lynch-associated CRC and adenomas.

METHODS

Systematic literature search in MEDLINE and EMBASE to identify studies investigating imaging techniques and biomarkers for detection of CRC and adenomas in Lynch syndrome. The QUADAS-2 tool was used for the quality assessment of included studies.

RESULTS

Seven of 1332 screened articles fulfilled the inclusion criteria. Two studies evaluated either CT colonography or MR colonography; both techniques were unable to detect CRC and (advanced) adenomas <10 mm. The other five studies evaluated plasma methylated-SEPTIN9, faecal immunochemical test (FIT), faecal tumour DNA markers (BAT-26, hMLH1, p53, D9S171, APC, D9S162, IFNA and DCC) and faecal microbiome as screening modalities. Sensitivity for CRC varied from 33% (BAT-26) to 70% (methylated-SEPTIN9) to 91% (hMLH1). High specificity (94-100%) for CRC and/or adenomas was observed for methylated-SEPTIN9, FIT and BAT-26. Desulfovibrio was enriched in the stool of patients having adenomas. However, all these studies were characterised by small populations, high/unclear risk of bias and/or low prevalence of adenomas.

CONCLUSIONS

Imaging techniques are unsuitable for colon surveillance in Lynch syndrome, whereas biomarkers are understudied. Having outlined biomarker research in Lynch-associated and sporadic CRC/adenomas, we believe that these non-invasive markers may hold potential (whether or not combined) for this population. As they could be of great value, (pre-)clinical studies in this field should be prioritised.

Faecal haemoglobin concentration in adenoma, before and after polypectomy, approaches the ideal tumour marker

Background

Polypectomy may be performed at colonoscopy and then subsequent surveillance undertaken. It is thought that faecal haemoglobin concentration (f-Hb), estimated by quantitative faecal immunochemical tests (FIT), might be a useful tumour marker.

Methods

Consecutive patients enrolled in colonoscopy surveillance were approached at two hospitals. A specimen for FIT was provided before colonoscopy and, ideally after 3 weeks, a second FIT sample from those who had polypectomy. A single FIT system (OC-Sensor io, Eiken Chemical Co., Ltd) was used to generate f-Hb.

Results

1103 Patients were invited; 643 returned a FIT device (uptake: 58.3%). Four patients had known inflammatory bowel disease (IBD) and were excluded, leaving 639 (57.9%) with an age range of 25–90 years (median 64 years), 54.6% male. Of 593 patients who had a f-Hb result and completed colonoscopy, advanced neoplasia was found in 41 (6.9%); four colorectal cancer (CRC): 0.7% and 37 advanced adenoma (AA): 6.3%, and a further 127 (21.4%) had non-advanced adenoma (NAA). The median f-Hb was significantly greater in AA as compared to NAA; 6.0 versus 1.0 μg Hb/g faeces, p < 0.0001.134/164 (81.7%) of invited patients returned a second FIT device: 28 were patients with AA in whom median pre-polypectomy f-Hb was 19.2, falling to 3.5 μg Hb/g faeces post-polypectomy, p = 0.01, and 106 with NAA had median pre-polypectomy f-Hb 0.8 compared to 1.0 μg Hb/g faeces post-polypectomy, p = 0.96.

Conclusions

Quantitative FIT could provide a good tumour marker in post-polypectomy surveillance, reduce colonoscopy requirements and minimise potential risk to patients.

Post-polypectomy colonoscopy surveillance: Can we improve the diagnostic yield?

Although adenomas and serrated polyps are the preneoplastic lesions of colorectal cancer, only few of them will eventually progress to cancer. This review provides a comprehensive overview of the present and future of post-polypectomy colonoscopy surveillance. Post-polypectomy surveillance guidelines have recently been updated and all share the aim towards more selective and less frequent surveillance. We have examined these current guidelines and compared the recommendations of each of them. To improve the diagnostic yield of post-polypectomy surveillance it is important to find predictors of metachronous polyps that better identify high-risk individuals of developing advanced neoplasia. For this reason, we have also conducted a literature review of the molecular biomarkers of metachronous advanced colorectal polyps. Finally, we have discussed future directions of post-polypectomy surveillance and identified possible strategies to improve the use of endoscopic resources with the COVID-19 pandemic.

Faecal Haemoglobin Estimated by Faecal Immunochemical Tests-An Indicator of Systemic Inflammation with Real Clinical Potential

Multimorbidity is the major cause of ill-health and premature death in developed countries. The ability to identify individuals at risk of developing chronic disease, particularly multimorbidity, reliably, and simply, and to identify undiagnosed disorders, is vital to reducing the global burden of disease. This narrative review, the first of recent studies, demonstrates that raised faecal haemoglobin concentration (f-Hb) is associated with increased all-cause and cause-specific mortality and with longer-term conditions including diabetes, hypertension, cardiovascular disease, and psoriasis, and with probable intake of particulate matter. We and others have hypothesized that elevated f-Hb (measured using a faecal immunochemical test) has considerable potential to identify individuals at risk of, or who already have, early stage, undiagnosed chronic disease. If f-Hb does prove to be an effective biomarker for chronic disease and multimorbidity, individuals with detectable f-Hb, but without an obvious source of gastrointestinal blood loss, could benefit from further assessment and early intervention. To test this hypothesis rigorously, longitudinal data-linkage methodology is required linking colorectal cancer screening data, and data on patients presenting with lower gastrointestinal symptoms, with routinely collected health information.

Faecal immunochemical test outside colorectal cancer screening?

Faecal immunochemical tests (FITs) are the most widely colorectal cancer (CRC) diagnostic biomarker available. Many population screening programmes are based on this biomarker, with the goal of reducing CRC mortality. Moreover, in recent years, a large amount of evidence has been produced on the use of FIT to detect CRC in patients with abdominal symptoms in primary healthcare as well as in surveillance after adenoma resection. The aim of this review is to highlight the available evidence on these two topics. We will summarize the evidence on diagnostic yield in symptomatic patients with CRC and significant colonic lesion and the different options to use this (thresholds, brands, number of determinations, prediction models and combinations). We will include recommendations on FIT strategies in primary healthcare proposed by regulatory bodies and scientific societies and their potential effects on healthcare resources and CRC prognosis. Finally, we will show information regarding FIT-based surveillance as an alternative to endoscopic surveillance after high-risk polyp resection. To conclude, due to the coronavirus disease 2019 pandemic, FIT-based strategies have become extremely relevant since they enable a reduction of colonoscopy demand and access to the healthcare system by selecting individuals with the highest risk of CRC.

Faecal haemoglobin distributions by sex, age, deprivation and geographical region: consequences for colorectal cancer screening strategies

Objectives Faecal immunochemical tests for haemoglobin (FIT) are becoming widely used in colorectal cancer (CRC) screening and assessment of symptomatic patients. Faecal haemoglobin concentration (f-Hb) thresholds are used to guide subsequent investigation. We established the distributions of f-Hb in a large screening population by sex, age, deprivation and geography. Methods Single estimates of f-Hb were documented for all individuals participating in the first 18 months of the Scottish Bowel Screening Programme (SBoSP). The distributions of f-Hb were generated for all participants, all men and women, and men and women by age quintile and deprivation quintile. Distributions were also generated by geographical region for all participants, men and women, and by deprivation. Comparisons of f-Hb distributions with those found in a pilot evaluation of FIT and three other countries were performed. Results f-Hb was documented for 887,248 screening participants, 422,385 men and 464,863 women. f-Hb varied by sex, age, deprivation quintile and geographical region. The f-Hb distributions by sex and age differed between the SBoSP and the pilot evaluation and the three other countries. Conclusions f-Hb is higher in men than in women and increases with age and deprivation in both sexes. f-Hb also varies by geographical region, independently of deprivation, and by country. The f-Hb distribution estimated by pilot evaluation may not represent the population distribution. Decision limits have advantages over reference intervals. Use of partitioned f-Hb thresholds for further investigation, based on the data generated, has advantages and disadvantages, as do risk scores based on a spectrum of influencing variables.

Faecal immunochemical tests for haemoglobin: Analytical challenges and potential solutions

Quantitative faecal immunochemical tests for haemoglobin (FIT) are being used increasingly around the world in colorectal cancer screening programmes, and in patients presenting with lower bowel symptoms to determine who should proceed to further bowel visualisation investigations, usually colonoscopy. The clinical utility of FIT is well reported. There are a number of analytical challenges including pre-analytical variation, difficulty setting up external quality assessment schemes, access to third party internal quality control material and a lack of standardisation or harmonisation of FIT methods. Here we report the work of the International Federation of Clinical Chemistry FIT Working Group. We provide an overview of the main pre-analytical variables; discuss different approaches to external quality assurance of FIT; propose a solution to third party internal quality assurance materials and summarise the challenges of standardisation and harmonisation of FIT.