Service evaluation of faecal immunochemical testing and anaemia for risk stratification in the 2-week-wait pathway for colorectal cancer

The increasing burden of the 2-week wait colorectal cancer pathway in a single centre: the impact of faecal immunochemical tests

INTRODUCTION

Two-week wait (TWW) volume and colorectal cancer (CRC) detection pose an increasing challenge for NHS cancer services. Primary aims were to assess the introduction of faecal immunochemical tests (FIT) into clinical practice at our centre, the impact on TWW referral volume and CRC diagnoses, and to provide an update to previously published work. A secondary aim was to correlate FIT value and investigation.

METHODS

TWW CRC data following incorporation of FIT into clinical practice were analysed (1 June 2019-31 July 2021). Parameters assessed were monthly referral volume, CRC detection, primary care FIT volume and secondary care investigations. Referrals and CRC detection rates were compared with previously published data (2009-2019). Data relating to primary care FIT were collated from Berkshire and Surrey Pathology Services.

RESULTS

TWW referrals increased 360% (2009-2020). CRC incidence decreased from 8.87% to 3.24%. Following incorporation into clinical practice, primary care FIT requests have increased to >450/month and accompanied 1,722/4,796 referrals. CRC incidence is static (3-4%). Patients with FIT <10µg Hb/g faeces undergo radiological imaging more commonly, whereas FIT-positive patients are more likely to undergo endoscopy, although the difference is not statistically significant.

CONCLUSIONS

No significant change in CRC diagnosis was observed, despite increasing TWW referrals. Increasing utilisation of FIT in both primary and secondary care has helped maintain CRC detection while avoiding diagnostic delay. This study supports growing evidence highlighting the value of FIT in triage, referral and TWW investigation. FIT appears increasingly important for allocating secondary care resources (endoscopy), while guiding primary care referral. Additional low-cost strategies to determine prioritisation or reassurance (e.g. repeat FIT) require further evaluation.

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.

'Low' faecal immunochemical test (FIT) colorectal cancer: a 4-year comparison of the Nottingham '4F' protocol with FIT10 in symptomatic patients

AIM

The aim of this work was to evaluate colorectal cancer (CRC) outcomes after 'low' (sub-threshold) faecal immunochemical test (FIT) results in symptomatic patients tested in primary care.

METHOD

This work comprised a retrospective audit of 35 289 patients with FIT results who had consulted their general practitioner with lower gastrointestinal symptoms and had subsequent CRC diagnoses. The Rapid Colorectal Cancer Diagnosis pathway was introduced in November 2017 to allow incorporation of FIT into clinical practice. The local '4F' protocol combined FIT results with blood tests and digital rectal examination (DRE): FIT, full blood count, ferritin and finger [DRE]. The outcome used was detection rates of CRC, missed CRC and time to diagnosis in local 4F protocols for patients with a subthreshold faecal haemoglobin (fHb) result compared with thresholds of 10 and 20 μg Hb/g faeces.

RESULTS

A single threshold of 10 μg Hb/g faeces identifies a population in whom the risk of CRC is 0.2%, but this would have missed 63 (10.5%) of 599 CRCs in this population. The Nottingham 4F protocol would have missed fewer CRCs [42 of 599 (7%)] despite using a threshold of 20 μg Hb/g faeces for patients with normal blood tests. Subthreshold FIT results in patients subsequently diagnosed with a palpable rectal tumour yielded the longest delays in diagnosis.

CONCLUSION

A combination of FIT with blood results and DRE (the 4F protocol) reduced the risk of missed or delayed diagnosis. Further studies on the impact of such protocols on the diagnostic accuracy of FIT are expected. The value of adding blood tests to FIT may be restricted to specific parts of the fHb results spectrum.

A service evaluation of the use of faecal immunochemical tests in symptomatic patients aged under 50 years presenting to primary care

BACKGROUND

Most colorectal cancers (CRCs) occur in individuals aged over 50 years; however, the incidence in younger age groups is increasing. Diagnosis in younger patients is frequently delayed due to non-specific symptoms and the relative frequency of benign disease. There is a need to identify patients who warrant further investigation for CRC. This study reviewed whether a faecal haemoglobin (f-Hb) ≥10 μg Hb/g faeces measured by the faecal immunochemical test for f-Hb (FIT) was associated with CRC in a local primary care population aged under 50 years.

METHODS

f-Hb results from symptomatic patients aged 18-49 years presenting to primary care during a 17-month period were extracted from local laboratory information systems. Colonoscopy lists were obtained from three local trusts. The Somerset Cancer Registry was searched to identify CRCs. f-Hb and outcomes were matched using NHS numbers.

RESULTS

A total of 3119 patients were included (median age 41 years); 313 of 2682 patients with f-Hb <10 μg/g (11.7%) and 305 of 437 patients with f-Hb ≥10 μg/g (69.8%) underwent colonoscopy. Twelve CRCs were detected. At a cut-off of 10 μg/g, the positivity rate was 14.0%, sensitivity was 100% (75.8-100%), specificity was 86.3% (85.1-87.5%), positive predictive value (PPV) was 2.7% (2.5-3.0%) and negative predictive value (NPV) was 100%. At a cut-off of 150 μg/g, sensitivity was 83.3% (55.2-95.3%), specificity was 95.2% (94.4-95.9%), PPV was 6.2% (4.7-8.2%) and NPV was 99.9% (99.8-100%).

CONCLUSION

Our data supports the use of FIT to triage patients aged under 50 years presenting to primary care with symptoms suggestive of CRCs.

Association between different types of preoperative anemia and tumor characteristics, systemic inflammation, and survival in colorectal cancer

Background

Patients with colorectal cancer often have anemia and other symptoms after diagnosis, especially in patients with advanced colorectal cancer. This study explored the association between different types of preoperative anemia and tumor characteristics and inflammatory response in patients with colorectal cancer and to evaluate the prognosis of patients with different types of anemia before operation.

Methods

The clinical data of 95 patients with colorectal cancer treated in the Fourth Hospital of Hebei Medical University from February 2016 to January 2018 were retrospectively analyzed. According to the hemoglobin concentration (Hb), mean corpuscular volume (MCV), mean hemoglobin content (MCH) and mean hemoglobin concentration (MCHC), the patients were divided into the non-anemia group, normal cell anemia group, and small cell anemia group. The three groups' general data, oncological characteristics, and mGPS scores were compared. The patients were followed up for five years, and the survival analysis was carried out. The cox proportional hazard regression model was used to analyze the prognostic factors of patients with colorectal cancer.

Results

The preoperative anemia rate of patients with colorectal cancer was 43.15% (41/95). There were significant differences in gender, weight loss, CA724, tumor location, tumor size, TNM stage, mGPS score, and positive expression rate of Ki-67 among different anemia groups. There was a significant difference in survival time among a non-anemia group, small cell anemia group, and normal cell anemia group (P < 0.05). Multivariate analysis showed that tumor size, TNM stage, distant metastasis, mGPS score, Ki-67 positive expression rate, and anemia type were independent risk factors affecting the prognosis of colorectal cancer patients (P < 0.05).

Conclusion

The oncological characteristics of colorectal cancer patients with different types of preoperative anemia are different. Preoperative anemia and systemic inflammatory status are independent risk factors for the prognosis of colorectal cancer patients.

Faecal haemoglobin: Measurement, applications, and future potential

Faecal hemoglobin concentrations (f-Hb) can be quantitated using faecal immunochemical test for haemoglobin (FIT) analytical systems. FIT are of proven value and widely used in colorectal cancer (CRC) screening. Several factors affect f-Hb including sex, age, deprivation, geographical region, and FIT system. Thus, FIT data may not be transferable. Women are disadvantaged in programmes using a single f-Hb threshold for all participants, but risk scoring or sex stratified thresholds could be used to minimise this problem. In addition, low but detectable f-Hb, below the threshold, implies future risk of CRC. In several countries, where colonoscopy resources are constrained, FIT are now accepted as of added value in assessment of patients presenting in primary or secondary care with symptoms, although some serious colorectal disease is missed. Elevated f-Hb in the absence of any discernible colorectal lesions is common and has been found in several diseases with a systemic inflammatory component, including circulatory, respiratory, digestive, neuropsychological, blood and endocrine diseases, and others. There is growing evidence for the value of f-Hb in post-polypectomy surveillance, potentially saving costs and colonoscopy. There may be a role for FIT systems which have lower limits of detection than currently available methods. The faecal material remaining in FIT specimen collection devices could be used for further studies, including assessment of the microbiome. The estimation of f-Hb is now a mature investigative tool but further research will undoubtedly expand applications of value.

Risk-stratified faecal immunochemical testing (FIT) for urgent colonoscopy in Lynch syndrome during the COVID-19 pandemic

BACKGROUND

Lynch syndrome is a hereditary cancer disease resulting in an increased risk of colorectal cancer. Herein, findings are reported from an emergency clinical service implemented during the COVID-19 pandemic utilizing faecal immunochemical testing ('FIT') in Lynch syndrome patients to prioritize colonoscopy while endoscopy services were limited.

METHODS

An emergency service protocol was designed to improve colonoscopic surveillance access throughout the COVID-19 pandemic in England for people with Lynch syndrome when services were extremely restricted (1 March 2020 to 31 March 2021) and promoted by the English National Health Service. Requests for faecal immunochemical testing from participating centres were sent to the National Health Service Bowel Cancer Screening South of England Hub and a faecal immunochemical testing kit, faecal immunochemical testing instructions, paper-based survey, and pre-paid return envelope were sent to patients. Reports with faecal haemoglobin results were returned electronically for clinical action. Risk stratification for colonoscopy was as follows: faecal haemoglobin less than 10 µg of haemoglobin/g of faeces (µg/g)-scheduled within 6-12 weeks; and faecal haemoglobin greater than or equal to 10 µg/g-triaged via an urgent suspected cancer clinical pathway. Primary outcomes of interest included the identification of highest-risk Lynch syndrome patients and determining the impact of faecal immunochemical testing in risk-stratified colonoscopic surveillance.

RESULTS

Fifteen centres participated from June 2020 to March 2021. Uptake was 68.8 per cent amongst 558 patients invited. For 339 eligible participants analysed, 279 (82.3 per cent) had faecal haemoglobin less than 10 µg/g and 60 (17.7 per cent) had faecal haemoglobin greater than or equal to 10 µg/g. In the latter group, the diagnostic accuracy of faecal immunochemical testing was 65.9 per cent and escalation to colonoscopy was facilitated (median 49 versus 122 days, χ2 = 0.0003, P < 0.001).

CONCLUSION

Faecal immunochemical testing demonstrated clinical value for Lynch syndrome patients requiring colorectal cancer surveillance during the pandemic in this descriptive report of an emergency COVID-19 response service. Further longitudinal investigation on faecal immunochemical testing efficacy in Lynch syndrome is warranted and will be examined under the 'FIT for Lynch' study (ISRCTN15740250).

An observational study of replicate faecal immunochemical tests in the urgently referred symptomatic cohort

INTRODUCTION

Triage of patients with suspected colorectal cancer (CRC) utilises a single faecal immunochemical test (FIT) at a defined threshold. Limited evidence exists regarding whether replicate FIT improves the positive and negative predictive value in symptomatic patients. This study examines urgently referred symptomatic patients undergoing replicate FIT. Primary aim is to assess two FITs and CRC/serious bowel disease. Secondary aims are to determine correlation and utility of replicate FIT.

METHODOLOGY

Patients carried out one additional FIT during COVID-19 pandemic. FIT 1 and FIT 2 (the replicate sample) were analysed in relation to symptoms, diagnoses, investigations, future colonoscopy and missed CRC. Study period was 01/03/2020-31/07/2020. Three subgroups were compared; double positive (≥10 μg Hb/g faeces), double negative, and discordant FIT (one positive).

RESULTS

111 patients had replicate FIT (50 male, 61 female). 43 (38.7%) patients had double negative, 32 (28.8%) double positive and 36 (32.4%) had discordant FITs. Median time between FITs was 14 days (IQR = 11-19). 83% of double positive patients underwent colonoscopy/virtual colonoscopy (61% in double negative patients). Six CRC and one high-risk polyp were in double positive patients (none in other groups). One discordant patient was not investigated and a CRC missed.

CONCLUSIONS

Replicate FIT as a triage strategy appears most effective where both FITs are negative. CRC risk is low when FIT results are discordant. Double negative FITs are reassuring given benign associated diagnoses, or for patients where endoscopic investigation is high-risk. Larger studies are required to evaluate discordant FITs, enabling refinement of urgent investigation pathways.

Adapting the investigation of patients on urgent suspected cancer pathway with lower gastrointestinal symptoms across Wales during COVID-19

INTRODUCTION

The COVID-19 pandemic necessitated the introduction of revised diagnostic pathways for assessing urgent suspected cancer (USC) referrals. Combinations of faecal immunochemical testing (FIT) and minimal preparation computed tomography (CT) scans (MPCT) were used to manage referrals and prioritise access to clinical services or invasive tests. The effectiveness of these pathways across Wales is evaluated in this study.

METHODS

All consecutive patients referred from primary care on the USC pathway between 15 March and 15 June 2020 were included to reflect the effect of full lockdown measures. Data collected included demographics, presenting symptom(s), investigations and timelines and patient outcomes up to 90 days following initial referral.

RESULTS

A total of 1,050 patients across eight sites in Wales were included. Of these 1,050 patients, 52.6% were female with median age 68 (21-97) years; 50.5% had first-line clinical review, of which 61.1% were virtual consultations; 49.5% had primary investigations; 26.7% of patients had FIT and 13.1% had MPCT. COVID-response pathways achieved a 29.9% reduction in use of colonoscopy as first-line investigation and 79% of patients avoided face-to-face consultations altogether during this first wave of the pandemic. Overall, 6.8% of USC referrals were diagnosed with colorectal cancer (CRC). Median timescale from diagnosis to treatment for CRC was 65 (4-175) days. The negative predictive value (NPV) for FIT in this cohort was 99.6%. MPCT as the first modality had a NPV of 99.2%.

CONCLUSION

A modified investigation pathway helped maintain cancer diagnosis rates during the pandemic with improved resource utilisation to that used prepandemic.

Understanding colorectal cancer risk for symptomatic patients in primary care: A cohort study utilising faecal immunochemical tests and blood results in England

BACKGROUND

A faecal immunochemical tests (FIT) cut-off of ≥10 μg Hb/g faeces is now recommended in the UK as a gateway to urgent (suspected cancer) investigation for colorectal cancer (CRC), based on an expected CRC risk threshold of 3%.

AIMS

To quantify the risk of CRC at FIT cut-offs by age, haemoglobin and platelet strata.

METHODS

A cohort study of a symptomatic CRC pathway based on primary care FIT tests in Nottingham, UK (November 2017-2021) with 1-year follow-up. Heat maps showed the cumulative 1-year CRC risk using Kaplan-Meier estimates.

RESULTS

In total, 514 (1.5%) CRCs were diagnosed following 33,694 index FIT requests. Individuals with a FIT ≥ 10 μg Hb/g faeces had a >3% risk of CRC, except patients under the age of 40 years (CRC risk 1.45% [95% CI: 0.03%-2.86%]). Non-anaemic patients with a FIT < 100 μg Hb/g faeces had a CRC risk of <3%, except those between the age of 70 and 85 years (5.26% 95% CI: 2.72%-7.73%). Using a ≥3% CRC threshold in patients <55 years calculated using FIT, age and anaemia might allow 160-220 colonoscopies per 10,000 FITs to be re-purposed, at a cost of missing 1-2 CRCs.

CONCLUSIONS

FIT alone with a single cut-off is unlikely to be a panacea for optimising CRC diagnosis, as risk varies by FIT, age and anaemia when faecal haemoglobin levels are below 100 μg Hb/g. Tailored FIT cut-offs for investigation on a CRC pathway could reduce the number of investigations needed at a 3% CRC risk threshold.

Double faecal immunochemical testing in patients with symptoms suspicious of colorectal cancer

BACKGROUND

Faecal immunochemical test (FIT)-directed pathways based on a single test have been implemented for symptomatic patients. However, with a single test, the sensitivity is 87 per cent at 10 µg haemoglobin (Hb) per g faeces. This aims of this study were to define the diagnostic performance of a single FIT, compared with double FIT in symptomatic populations.

METHODS

Two sequential prospective patient cohorts referred with symptoms from primary care were studied. Patients in cohort 1 were sent a single FIT, and those in cohort 2 received two tests in succession before investigation. All patients were investigated, regardless of having a positive or negative test (threshold 10 µg Hb per g).

RESULTS

In cohort 1, 2260 patients completed one FIT and investigation. The sensitivity of single FIT was 84.1 (95 per cent c.i. 73.3 to 91.8) per cent for colorectal cancer and 67.4 (61.0 to 73.4) per cent for significant bowel pathology. In cohort 2, 3426 patients completed at least one FIT, and 2637 completed both FITs and investigation. The sensitivity of double FIT was 96.6 (90.4 to 99.3) per cent for colorectal cancer and 83.0 (77.4 to 87.8) per cent for significant bowel pathology. The second FIT resulted in a 50.0 per cent reduction in cancers missed by the first FIT, and 30.0 per cent for significant bowel pathology. Correlation between faecal Hb level was only modest (rs = 0.58), and 16.8 per cent of double tests were discordant, 11.4 per cent in patients with colorectal cancer and 18.3 per cent in those with significant bowel pathology.

CONCLUSION

FIT in patients with high-risk symptoms twice in succession reduces missed significant colorectal pathology and has an acceptable workload impact.

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.

Evaluation of 13,466 Fecal Immunochemical Tests in Patients Attending Primary Care for High- and Low-Risk Gastrointestinal Symptoms of Colorectal Cancer

AIM/OBJECTIVE

Quantitative fecal immunochemical tests (FIT) were recommended by NICE for patients in primary care presenting with low-risk symptoms of colorectal cancer (CRC). FIT is more accurate in the detection of CRC than symptom criteria. Despite this, CRC still occurs with a negative FIT and the importance of safety netting for patients with severe or persistent symptoms is paramount. We aimed to evaluate the utilization and accuracy of FIT for CRC in low and high-risk symptom groups presenting to primary care, the effectiveness of safety netting in primary care, referral practices with FIT utilization for symptomatic patients and the clinical features of FIT negative patients with CRC.

MATERIALS AND METHODS

Medical records and databases of all patients undertaking a FIT sample in the Herts Valleys CCG between June 2019 and November 2021 were reviewed. 13,466 consecutive FIT samples were requested for 12,231 patients between June 2019 and November 2021.

RESULTS

Analysis of diagnostic accuracy was undertaken for the first 5341 patients with a minimum of 12 months follow up. Sensitivity for CRC, in FIT ≥ 4 µg Hb/g, ≥ 10 µg Hb/g and ≥ 100 µg Hb/g was 93% (95% CI 85-98%), 91% (95% CI 82-96%) and 72% (95% CI 60-81%) with a number needed to investigate of 36, 19 and 6, respectively.

CONCLUSION

A FIT ≥ 10 µg Hb/g in conjunction with ongoing GP clinical concern within 8 weeks had a sensitivity for CRC of 97% (95% CI 90-100%), a PPV of 3.6% (95% CI 3.4-3.7%) and a number needed to investigate to detect one CRC of 28.

Exploring the utility and acceptability of Faecal immunochemical testing (FIT) as a novel intervention for the improvement of colorectal Cancer (CRC) surveillance in individuals with lynch syndrome (FIT for lynch study): a single-arm, prospective, multi-centre, non-randomised study

BACKGROUND

Lynch Syndrome (LS) is an inherited cancer predisposition syndrome defined by pathogenic variants in the mismatch repair (MMR) or EPCAM genes. In the United Kingdom, people with LS are advised to undergo biennial colonoscopy from as early as 25 until 75 years of age to mitigate a high lifetime colorectal cancer (CRC) risk, though the consideration of additional surveillance intervention(s) through the application of non-invasive diagnostic devices has yet to be longitudinally observed in LS patients. In this study, we will examine the role of annual faecal immunochemical testing (FIT) alongside biennial colonoscopy for CRC surveillance in people with LS.

METHODS/DESIGN

In this single-arm, prospective, non-randomised study, 400 LS patients will be recruited across 11 National Health Service (NHS) Trusts throughout the United Kingdom. Study inclusion requires a LS diagnosis, between 25 and 73 years old, and a routine surveillance colonoscopy scheduled during the recruitment period. Eligible patients will receive a baseline OC-Sensor™ FIT kit ahead of their colonoscopy, and annually for 3 years thereafter. A pre-paid envelope addressed to the central lab will be included within all patient mailings for the return of FIT kits and relevant study documents. A questionnaire assessing attitudes and perception of FIT will also be included at baseline. All study samples received by the central lab will be assayed on an OC-Sensor™ PLEDIA Analyser. Patients with FIT results of ≥6 μg of Haemoglobin per gram of faeces (f-Hb) at Years 1 and/or 3 will be referred for colonoscopy via an urgent colonoscopy triage pathway. 16S rRNA gene V4 amplicon sequencing will be carried out on residual faecal DNA of eligible archived FIT samples to characterise the faecal microbiome.

DISCUSSION

FIT may have clinical utility alongside colonoscopic surveillance in people with LS. We have designed a longitudinal study to examine the efficacy of FIT as a non-invasive modality. Potential limitations of this method will be assessed, including false negative or false positive FIT results related to specific morphological features of LS neoplasia or the presence of post-resection anastomotic inflammation. The potential for additional colonoscopies in a subset of participants may also impact on colonoscopic resources and patient acceptability.

TRIAL REGISTRATION

Trial Registration: ISRCTN, ISRCTN15740250 . Registered 13 July 2021.

Faecal immunochemical testing (FIT) in patients with signs or symptoms of suspected colorectal cancer (CRC): a joint guideline from the Association of Coloproctology of Great Britain and Ireland (ACPGBI) and the British Society of Gastroenterology (BSG)

Faecal immunochemical testing (FIT) has a high sensitivity for the detection of colorectal cancer (CRC). In a symptomatic population FIT may identify those patients who require colorectal investigation with the highest priority. FIT offers considerable advantages over the use of symptoms alone, as an objective measure of risk with a vastly superior positive predictive value for CRC, while conversely identifying a truly low risk cohort of patients. The aim of this guideline was to provide a clear strategy for the use of FIT in the diagnostic pathway of people with signs or symptoms of a suspected diagnosis of CRC. The guideline was jointly developed by the Association of Coloproctology of Great Britain and Ireland/British Society of Gastroenterology, specifically by a 21-member multidisciplinary guideline development group (GDG). A systematic review of 13 535 publications was undertaken to develop 23 evidence and expert opinion-based recommendations for the triage of people with symptoms of a suspected CRC diagnosis in primary care. In order to achieve consensus among a broad group of key stakeholders, we completed an extended Delphi of the GDG, and also 61 other individuals across the UK and Ireland, including by members of the public, charities and primary and secondary care. Seventeen research recommendations were also prioritised to inform clinical management.

Faecal immunochemical tests safely enhance rational use of resources during the assessment of suspected symptomatic colorectal cancer in primary care: systematic review and meta-analysis

OBJECTIVE

Implementation of faecal immunochemical tests (FIT) as a triage test in primary healthcare may improve the efficiency of referrals without missing cases of colorectal cancer (CRC). We aim to summarise the performance characteristics of FITs for CRC in symptomatic patients presenting to primary healthcare.

DESIGN

We performed a systematic literature review of Medline and EMBASE databases from May 2018 to November 2020. Previous related systematic searches were also adapted to this aim and completed with reference screening. We identified studies performed on adult patients consulting for abdominal symptoms in primary care which reported data such that the FIT diagnostic performance parameters for CRC could be obtained. Bivariate models were used to synthesise available evidence. Meta-regression analysis was performed to evaluate the causes of heterogeneity.

RESULTS

Twenty-three studies (69 536 participants) were included (CRC prevalence 0.3%-6.2%). Six studies (n=34 691) assessed FIT as rule in test (threshold of ≥150 µg Hb/g faeces) showing a sensitivity of 64.1% (95% CI 57.8% to 69.9%) and a specificity of 95.0% (95% CI 91.2% to 97.2%). A threshold of 10 µg/g (15 studies; n=48 872) resulted in a sensitivity of 87.2% (95% CI 81.0% to 91.6%) and a specificity of 84.4% (95% CI 79.4% to 88.3%) for CRC. At a 20 µg Hb/g faeces threshold (five studies; n=24 187) less than one additional CRC would be missed per 1000 patients investigated compared with 10 µg Hb/g faeces threshold (CRC prevalence 2%).

CONCLUSION

FIT is the test of choice to evaluate patients with new-onset lower gastrointestinal symptoms in primary healthcare.

The diagnostic accuracy of the faecal immunohistochemical test in identifying significant bowel disease in a symptomatic population

AIM

Provisional research on the faecal immunohistochemical test (FIT) for symptomatic colorectal patients has shown a high negative predictive value but has lacked long-term patient follow-up, raising the possibility of missed diagnoses of colorectal cancer (CRC). The aim of this work is to describe the long-term diagnostic accuracy of the FIT for CRC and significant bowel disease (SBD) in a symptomatic population in NHS Lanarkshire.

METHOD

From October 2016 to February 2019, all primary care referrals of symptomatic colorectal patients in NHS Lanarkshire were asked to provide a FIT. The baseline demographics, investigations and diagnoses for each patient were prospectively completed until February 2021. A FIT result of ≥10 μg haemoglobin (Hb)/g faeces was considered to be positive.

RESULTS

A total of 5250 patients were identified (median age 62 years; 46% male; median follow-up 31 months) with 65.1% (3418) being FIT negative. The SBD rate was 6.2% and the CRC rate was 2.9% (151). The SBD rate was significantly higher in the FIT-positive group (13.8% vs. 2.2%; p < 0.001) and 32.9% of patients with FIT ≥ 400 μg Hb/g had SBD. The sensitivity of FIT ≥ 10 μg Hb/g for CRC was 87.4% and for SBD it was 76.9%. Specificity was 66.6% and 66.7%, and the negative-predictive value was 99.4% and 97.7%, respectively. Sensitivity for CRC could theoretically be increased to 94.8% if FIT-negative patients were to undergo flexible sigmoidoscopy.

CONCLUSION

A FIT-only referral pathway for symptomatic colorectal patients will miss over 12% of cancers and over 23% of SBD. Theoretically, combining FIT-negative patients with flexible sigmoidoscopy increases the sensitivity for CRC. The FIT offers a mechanism for prioritizing patient access to investigations, particularly in resource-limited areas; however, further work to identify FIT-negative patients diagnosed with CRC is required.

Faecal immunochemical test for suspected colorectal cancer symptoms: patient survey of usability and acceptability

BACKGROUND

Recent evidence suggests that the faecal immunochemical test (FIT) can rule out colorectal cancer (CRC) in symptomatic patients. To date, there is no research on usability and perception of FIT for these patients.

AIM

To measure variation in attitudes and perception of FIT in patients with suspected CRC symptoms.

DESIGN & SETTING

A cross-sectional survey of a subset of participants of the NICE FIT study.

METHOD

A questionnaire was co-developed with patients covering four themes on a Likert scale: FIT feasibility, faecal aversion, patient knowledge, and future intentions. Questionnaire and FIT kits were sent to patients with suspected CRC symptoms participating in the NICE FIT study. Logistic regression explored differences in patients' test perception by ethnic group, language, age, location, deprivation, FIT use, and previous experience.

RESULTS

A total of 1151 questionnaires were analysed; 90.2% (95% confidence interval [CI] = 88.3% to 91.8%) of patients found faecal collection straightforward, 76.3% (95% CI = 73.7% to 78.6%) disagreed FIT was unhygienic, and 78.1% (95% CI = 75.6% to 80.4%) preferred FIT to colonoscopy. Preference for FIT over colonoscopy was weaker in patients aged 40-64 years than those >65 years (odds ratio [OR] 0.60; 95% CI = 0.43 to 0.84). Intention to use FIT again was stronger in patients who successfully used FIT than those unsuccessful (OR 11.08; 95% CI = 2.74 to 44.75), and white compared with non-white patients assessed (OR 3.20; 95% CI = 1.32 to 7.75).

CONCLUSION

While most patients found FIT practical and hygienic, perception differences were found. Strategies to engage patients with more negative FIT perception should underpin symptomatic FIT pathways.

Combining the quantitative faecal immunochemical test and full blood count reliably rules out colorectal cancer in a symptomatic patient referral pathway

PURPOSE

Faecal Immunochemical Test (FIT) has proven utility for Colorectal Cancer (CRC) detection in symptomatic patients. Most studies have examined FIT in symptomatic patients subsequently referred from primary care. We investigated associations between CRC and FIT in both referred and non-referred symptomatic patients.

METHODS

A retrospective, observational study of all patients with a FIT submitted Aug 2018 to Jan 2019 in NHS GG&C was performed. Referral to colorectal/gastroenterology and decision to perform colonoscopy were recorded. FIT results were grouped as f-Hb < 10/10-149/150-399/ ≥ 400 μg/g. The MCN cancer registry identified new cases of CRC. Covariables were compared using the χ2 test. Multivariate binary logistic regression identified independent predictors of CRC.

RESULTS

A total of 4968 patients were included. Raised FIT correlated with decision to refer (p < 0.001) and scope (p < 0.001). With 23-month median follow-up, 61 patients were diagnosed with CRC. These patients were older (median 69 vs 59 years, cancer and no cancer respectively, p = 0.001), more likely to be male (55.7% vs 42.1%, p = 0.033), and to report rectal bleeding (51.7% vs 36.1%, p = 0.013). FIT (< 10 µg/g 8.2% vs 76.7% and ≥ 400 µg/g 55.7% vs 3.8%, p < 0.001) and anaemia (45.9% vs 19.7%, p < 0.001) were associated with CRC. On multivariate analysis, age (p = 0.023), male sex (p = 0.04), FIT (≥ 400 OR 54.256 (95% CI:20.683-142.325; p < 0.001)), and anaemia (OR 1.956 (1.071-3.574; p = 0.029)) independently predicted CRC. One patient (0.04%) with a negative FIT and normal haemoglobin had CRC.

CONCLUSION

GP referral and secondary care investigation patterns were influenced by FIT. The combination of normal Hb and f-Hb excluded CRC in 99.96% of cases, providing excellent reassurance to those prioritising access to endoscopy services.

Faecal immunochemical test to triage patients with possible colorectal cancer symptoms: meta-analysis

BACKGROUND

This review evaluated the utility of single quantitative faecal immunochemical test (FIT) as a triaging tool for patients with symptoms of possible colorectal cancer, the effect of symptoms on FIT accuracy, and the impact of triaging incorporating FIT on service provision.

METHODS

Five databases were searched. Meta-analyses of the extracted FIT sensitivities and specificities for detection of colorectal cancer at reported f-Hb thresholds were performed. Secondary outcomes included sensitivity and specificity of FIT for advanced colorectal neoplasia and serious bowel disease. Subgroup analysis by FIT brand and symptoms was undertaken.

RESULTS

Fifteen prospective cohort studies, including 28 832 symptomatic patients were included. At the most commonly reported f-Hb positivity threshold of ≥ 10 µg Hb/g faeces (n=13), the summary sensitivity was 88.7% (95% c.i. 85.2 to 91.4) and the specificity was 80.5% (95% c.i. 75.3 to 84.8) for colorectal cancer. At lower limits of detection of ≥ 2 µg Hb/g faeces, the summary sensitivity was 96.8% (95% c.i. 91.0 to 98.9) and the specificity was 65.6% (95% c.i. 59.0 to 71.6). At the upper f-Hb positivity thresholds of ≥ 100 µg Hb/g faeces and ≥ 150 µg Hb/g faeces, summary sensitivities were 68.1% (95% c.i. 59.2 to 75.9) and 66.3% (95% c.i. 52.2 to 78.0), with specificities of 93.4% (95% c.i. 91.3 to 95.1) and 95.1% (95% c.i. 93.6 to 96.3) respectively. FIT sensitivity was comparable between different assay brands. FIT sensitivity may be higher in patients reporting rectal bleeding.

CONCLUSION

Single quantitative FIT at lower f-Hb positivity thresholds can adequately exclude colorectal cancer in symptomatic patients and provides a data-based approach to prioritization of colonoscopy resources.

Faecal immunochemical test for patients with 'high-risk' bowel symptoms: a large prospective cohort study and updated literature review

Background

We evaluated whether faecal immunochemical testing (FIT) can rule out colorectal cancer (CRC) among patients presenting with ‘high-risk’ symptoms requiring definitive investigation.

Methods

Three thousand five hundred and ninety-six symptomatic patients referred to the standard urgent CRC pathway were recruited in a multi-centre observational study. They completed FIT in addition to standard investigations. CRC miss rate (percentage of CRC cases with low quantitative faecal haemoglobin [f-Hb] measurement) and specificity (percentage of patients without cancer with low f-Hb) were calculated. We also provided an updated literature review.

Results

Ninety patients had CRC. At f-Hb < 10 µg/g, the miss rate was 16.7% (specificity 80.1%). At f-Hb < 4 µg/g, the miss rate was 12.2% (specificity 73%), which became 3.3% if low FIT plus the absence of anaemia and abdominal pain were considered (specificity 51%). Within meta-analyses of 9 UK studies, the pooled miss rate was 7.2% (specificity 74%) for f-Hb < 4 µg/g.

Discussion

FIT alone as a triage tool would miss an estimated 1 in 8 cases in our study (1 in 14 from meta-analysis), while many people without CRC could avoid investigations. FIT can focus secondary care diagnostic capacity on patients most at risk of CRC, but more work on safety netting is required before incorporating FIT triage into the urgent diagnostic pathway.

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.

British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults

Iron deficiency anaemia (IDA) is a major cause of morbidity and burden of disease worldwide. It can generally be diagnosed by blood testing and remedied by iron replacement therapy (IRT) using the oral or intravenous route. The many causes of iron deficiency include poor dietary intake and malabsorption of dietary iron, as well as a number of significant gastrointestinal (GI) pathologies. Because blood is iron-rich it can result from chronic blood loss, and this is a common mechanism underlying the development of IDA-for example, as a consequence of menstrual or GI blood loss.Approximately a third of men and postmenopausal women presenting with IDA have an underlying pathological abnormality, most commonly in the GI tract. Therefore optimal management of IDA requires IRT in combination with appropriate investigation to establish the underlying cause. Unexplained IDA in all at-risk individuals is an accepted indication for fast-track secondary care referral in the UK because GI malignancies can present in this way, often in the absence of specific symptoms. Bidirectional GI endoscopy is the standard diagnostic approach to examination of the upper and lower GI tract, though radiological scanning is an alternative in some situations for assessing the large bowel. In recurrent or refractory IDA, wireless capsule endoscopy plays an important role in assessment of the small bowel.IDA may present in primary care or across a range of specialties in secondary care, and because of this and the insidious nature of the condition it has not always been optimally managed despite the considerable burden of disease- with investigation sometimes being inappropriate, incorrectly timed or incomplete, and the role of IRT for symptom relief neglected. It is therefore important that contemporary guidelines for the management of IDA are available to all clinicians. This document is a revision of previous British Society of Gastroenterology guidelines, updated in the light of subsequent evidence and developments.

Colorectal cancer and the blood loss paradox

BACKGROUND

Faecal occult blood (FOB) positivity and iron deficiency anaemia (IDA) are common manifestations of colorectal cancer (CRC) and both potentially facilitate diagnosis at an earlier, more treatable stage. It has been assumed that both are the consequence of low-grade blood loss from the tumour bed.

METHOD

A retrospective analysis of 1121 cases of CRC diagnosed at a single centre between 2010 and 2016, comparing cases presenting via FOB-based Bowel Cancer Screening Programme (BCSP) and IDA pathways for a series of variables including age, sex, tumour location and prevalence of anaemia.

RESULTS

The BCSP and IDA pathways each accounted for about 15% of the total case load. There were significant differences between the BCSP and IDA sub-groups in median age (68 vs 78 years: p<0.001), median haemoglobin (138 vs 89 g/L: p<0.001) and proportion of lesions in right colon (31.1% vs 82.5%: p<0.001). The major disparity in the prevalence of anaemia (overall 20.0% vs 98.2%: p<0.001) persisted when controlled for tumour location.

CONCLUSION

Paradoxically, CRC screening through the detection of FOB positivity and IDA identifies distinctly different sub-populations of cases. The theoretical implication is that an additional mechanism may be required to explain the development of IDA in CRC. The practical implication is that detection of IDA may have a complementary role to the BCSP in population screening for CRC.

The Fast Track FIT study: diagnostic accuracy of faecal immunochemical test for haemoglobin in patients with suspected colorectal cancer

Background

The faecal immunochemical test (FIT) is now available to support clinicians in the assessment of patients at low risk of colorectal cancer (CRC) and within the bowel cancer screening programme.

Aim

To determine the diagnostic accuracy of FIT for CRC and clinically significant disease in patients referred as they were judged by their GP to fulfil National Institute for Health and Care Excellence guideline 12 (NG12) criteria for suspected CRC.

Design and setting

Patients referred from primary care with suspected CRC, meeting NG12 criteria, to 12 secondary care providers in Yorkshire and Humber were asked to complete a FIT before investigation.

Method

The diagnostic accuracy of FIT based on final diagnosis was evaluated using receiver operating characteristics analysis. This permitted a statistically optimal cut-off value for FIT to be determined based on the maximisation of sensitivity and specificity. Clinicians and patients were blinded to the FIT results.

Results

In total, 5040 patients were fully evaluated and CRC was detected in 151 (3.0%). An optimal cut-off value of 19 µg Hb/g faeces for CRC was determined, giving a sensitivity of 85.4% (95% confidence interval [CI] = 78.8% to 90.6%) and specificity of 85.2% (95% CI = 84.1% to 86.2%). The negative predictive value at this cut-off value was 99.5% (95% CI = 99.2% to 99.7%) and the positive predictive value 15.1% (95% CI = 12.8% to 17.7%). Sensitivity and specificity of FIT for CRC and significant premalignant polyps at this cut-off value were 62.9% (95% CI = 57.5% to 68.0%) and 86.4% (95% CI = 85.4% to 87.4%), respectively; and when including all organic enteric disease were 35.7% (95% CI = 32.9% to 38.5%) and 88.6% (95% CI = 87.5% to 89.6%), respectively.

Conclusion

FIT used in patients fulfilling NG12 criteria should allow for a more personalised CRC risk assessment. FIT should permit effective, patient-centred decision-making to inform the need for, type, and timing of further investigation.

Yield of colorectal cancer at colonoscopy according to faecal haemoglobin concentration in symptomatic patients referred from primary care

AIM

Lower gastrointestinal (GI) symptoms are poor predictors of colorectal cancer (CRC). The aim of this study was to examine the diagnostic yield of colonoscopy by faecal haemoglobin (f-Hb) concentration in symptomatic patients assessed in primary care by faecal immunochemical testing (FIT).

METHOD

In three Scottish NHS Boards, FIT kits (HM-JACKarc, Hitachi Chemical Diagnostics Systems Co., Ltd, Tokyo, Japan) were used by general practitioners to guide referrals for patients with lower GI symptoms (laboratory data studied for 12 months from December 2015 onwards in Tayside, 18 months from June 2018 onwards in Fife and 5 months from September 2018 onwards in Greater Glasgow and Clyde). Cases of CRC diagnosed at colonoscopy were ascertained from colonoscopy and pathology records.

RESULTS

Four thousand eight hundred and forty one symptomatic patients who underwent colonoscopy after FIT submission were included. Of the 2166 patients (44.7%) with f-Hb <10 µg Hb/g faeces (µg/g), 14 (0.6%) were diagnosed with CRC, with a number needed to scope (NNS) of 155. Of the 2675 patients (55.3%) with f-Hb ≥10 µg/g, 252 were diagnosed with CRC (9.4%) with a NNS of 11. Of the 705 patients with f-Hb ≥400 µg/g, 158 (22.4%) were diagnosed with CRC with a NNS of 5. Over half of those diagnosed with CRC with f-Hb <10 µg/g had coexisting anaemia.

CONCLUSION

Symptomatic patients with f-Hb ≥10 µg/g should undergo further investigation for CRC, while higher f-Hb concentrations could be used to triage for urgency during the COVID-19 recovery phase. Patients with f-Hb <10 µg/g and without anaemia are very unlikely to be diagnosed with CRC and the majority need no further investigation.

Using the faecal immunochemical test in patients with rectal bleeding: evidence from the NICE FIT study

AIM

The aim of this work was to investigate whether the faecal immunochemical test (FIT) could safely rule out colorectal cancer (CRC) in patients with rectal bleeding (RB).

METHOD

This was a multicentre, double-blinded diagnostic accuracy study in 50 National Health Service hospitals. Patients referred from primary care with suspected CRC on an urgent 2-week-wait pathway were asked to perform a FIT prior to colonoscopy. The primary outcome measure was the sensitivity of the FIT for CRC in patients with RB versus nonrectal bleeding symptoms (NRB). The secondary outcome measures included the diagnostic accuracy of the FIT for CRC and other serious bowel disease.

RESULTS

Of 9822 patients included in the study, 3143 (32.0%) were referred with RB. CRC was present in 4.7% of patients with RB versus 2.7% of patients with NRB (p < 0.05). Faecal haemoglobin (f-Hb) was detectable (>2 µg/g) in 44.1% of patients with RB and 33.9% with NRB (p < 0.05). In RB patients, CRC was present in 10.4% when f-Hb was >2 µg/g compared with 0.1% when f-Hb was not detected. Flexible sigmoidoscopy in this group would further reduce the risk of CRC to 0.03%. The sensitivity of the FIT for CRC in RB versus NRB groups was 98.6% (95% CI 95.2%-99.8%) vs 95.6% (91.5%-98.1%) for f-Hb >2 µg/g and 96.6% (92.2%-98.9%) vs 86.3 (80.4%-90.9%) for f-Hb >10 µg/g.

CONCLUSION

Faecal haemoglobin is not always detectable in patients with RB; 56% of patients had undetectable f-Hb (<2 µg/g) and CRC was present in 0.1%. The high sensitivity of the FIT can be used to rule out CRC in patients with RB and triage them more appropriately for investigation.

Prioritisation of lower gastrointestinal endoscopy during the COVID-19 pandemic: outcomes of a novel triage pathway

OBJECTIVE

The 2-week-wait (2ww) referral pathway is used in England to fast-track patients with suspected colorectal cancer (CRC). A two-stage triage pathway was used to prioritise lower gastrointestinal (LGI) endoscopy for suspected CRC during the COVID-19 pandemic.

METHOD

All patients referred for an LGI endoscopy via a 2ww referral pathway between March 2020 and July 2020 were assessed. The first stage triaged patients to high, standard or low risk of CRC based on symptoms and faecal immunochemical test (FIT), and offered CT scans to those at high risk. The second stage, endoscopy prioritisation (EP), incorporated the CT results, FIT and symptoms to triage into four groups, EP1-EP4; with EP1 being the most urgent and EP4 the least. The primary outcome measure was CRC detection.

RESULTS

514 patients were included. The risk of CRC was triaged as high in 190/514 patients (37%), standard in 274/514 patients (53%) and low in 50/514 (10%) patients. 422/514 patients (82%) underwent endoscopy with triage to EP1 in 52/422 (12%), EP2 in 105/422 (25%), EP3 in 210/422 (50%) and EP4 in 55/422 (13%). CRC was detected in 23 patients (5.4%). CRC was significantly more frequent in the EP1 group (23.1%, relative risk (RR)=16.2) and EP2 group (6.7%, RR=4.7) compared with EP3 group (1.4%). All CRC lesions were identified by CT imaging when performed prior to LGI endoscopy.

CONCLUSION

This triage pathway designated 83% of patients with CRC to either EP1 or EP2. During a period of limited endoscopy provision, this pathway effectively prioritises endoscopy for those at greatest risk of CRC.

Faecal immunochemical test is superior to symptoms in predicting pathology in patients with suspected colorectal cancer symptoms referred on a 2WW pathway: a diagnostic accuracy study

OBJECTIVE

To assess whether a faecal immunochemical test (FIT) could be used to select patients with suspected colorectal cancer (CRC) symptoms for urgent investigation.

DESIGN

Multicentre, double-blinded diagnostic accuracy study in 50 National Health Service (NHS) hospitals across England between October 2017 and December 2019. Patients referred to secondary care with suspected CRC symptoms meeting NHS England criteria for urgent 2 weeks wait referral and triaged to investigation with colonoscopy were invited to perform a quantitative FIT. The sensitivity of FIT for CRC, and effect of relevant variables on its diagnostic accuracy was assessed.

RESULTS

9822 patients were included in the final analysis. The prevalence of CRC at colonoscopy was 3.3%. The FIT positivity decreased from 37.2% to 19.0% and 7.6%, respectively, at cut-offs of 2, 10 and 150 µg haemoglobin/g faeces (µg/g). The positive predictive values of FIT for CRC at these cut-offs were 8.7% (95% CI, 7.8% to 9.7%), 16.1% (95% CI 14.4% to 17.8%) and 31.1% (95% CI 27.8% to 34.6%), respectively, and the negative predictive values were 99.8% (95% CI 99.7% to 99.9%), 99.6% (95% CI 99.5% to 99.7%) and 98.9% (95% CI 98.7% to 99.1%), respectively. The sensitivity of FIT for CRC decreased at the same cut-offs from 97.0% (95% CI 94.5% to 98.5%) to 90.9% (95% CI 87.2% to 93.8%) and 70.8% (95% CI 65.6% to 75.7%), respectively, while the specificity increased from 64.9% (95% CI 63.9% to 65.8%) to 83.5% (95% CI 82.8% to 84.3%) and 94.6% (95% CI 94.1% to 95.0%), respectively. The area under the receiver operating characteristic curve was 0.93 (95% CI 0.92 to 0.95).

CONCLUSION

FIT sensitivity is maximised to 97.0% at the lowest cut-off (2 µg/g); a negative FIT result at this cut-off can effectively rule out CRC and a positive FIT result is better than symptoms to select patients for urgent investigations.

TRIAL REGISTRATION NUMBER

ISRCTN49676259.

GP access to FIT increases the proportion of colorectal cancers detected on urgent pathways in symptomatic patients in Nottingham

OBJECTIVE

Service evaluation of GP access to Faecal Immunochemical Test (FIT) for colorectal cancer (CRC) detection in Nottinghamshire and use of FIT for "rule out", "rule in" and "first test selection".

DESIGN

Retrospective audit of FIT results, CRC outcomes and resource utilisation before and after introduction of FIT in Primary Care in November 2017. Data from the new pathway up to December 2018 was compared with previous experience.

RESULTS

Between November 2017 and December 2018, 6747 GP FIT test requests yielded 5733 FIT results, of which 4082 (71.2%) were <4.0 μg Hb/g faeces, 579 (10.1%) were 4.0-9.9 μg Hb/g faeces, 836 (14.6%) were 10.0-149.9 μg Hb/g faeces, and 236 (4.1%) were ≥150.0 μg Hb/g faeces. The proportion of "rule out" results <4.0 μg Hb/g faeces was significantly higher than in the Getting FIT cohort (71.2% vs 60.4%, Chi squared 42.8, p < 0.0001) and the proportion of "rule in" results ≥150.0 μg Hb/g faeces was significantly lower (4.1% vs 8.1%, Chi squared 27.3,P < 0.0001). There was a 33% rise in urgent referrals across Nottingham overall during the evaluation period. 2 CRC diagnoses were made in 4082 patients who had FIT<4.0 μg Hb/g faeces. 58.4% of new CRC diagnoses associated with a positive FIT were early stage cancers (Stage I and II). The proportion of all CRC diagnoses that follow an urgent referral s rose after introduction of FIT.

CONCLUSIONS

FIT allows GP's to select a more appropriate cohort for urgent investigation without a large number of missed diagnoses. FIT appears to promise a "stage migration" effect which may ultimately improve CRC outcomes.

Faecal immunochemical testing in symptomatic patients to prioritize investigation: diagnostic accuracy from NICE FIT Study

BACKGROUND

This study investigated whether a quantitative faecal immunochemical test (FIT) could be used to select patients with either high- or low-risk symptoms of colorectal cancer for urgent investigation.

METHODS

A double-blinded diagnostic accuracy study was conducted in 50 hospitals in England between October 2017 and December 2019. Patients were eligible for inclusion if they had been referred to secondary care with suspected colorectal cancer symptoms meeting national criteria for urgent referral and triaged to investigation with colonoscopy.

RESULTS

The study included 9822 patients, of whom 7194 (73.2 per cent) had high-risk symptoms, 1994 (20.3 per cent) low-risk symptoms, and 634 (6.5 per cent) had other symptoms warranting urgent referral. In patients with high-risk symptoms, the sensitivity of FIT for colorectal cancer at cut-off values of 2 and 10 μg haemoglobin per g faeces was 97.7 (95 per cent c.i. 95.0 to 99.1) and 92.2 (88.2 to 95.2) per cent respectively, compared with 94.3 (84.3 to 98.8) and 86.8 (74.7 to 94.5) per cent in patients with low-risk symptoms at the same cut-off points. At cut-off values of 2, 10, and 150 μg/g, the positive predictive value for colorectal cancer was 8.9, 16.2, and 30.5 per cent respectively for those with high-risk symptoms, and 8.4, 16.9, and 35.5 per cent for those with low-risk symptoms.

CONCLUSION

FIT safely selects patients with high or low risk symptoms of colorectal cancer for investigation.

Faecal immunochemical testing (FIT): sources of result variation based on three years of routine testing of symptomatic patients in English primary care

Introduction: We aimed to determine the analytical capabilities of a commonly used faecal immunochemical test (FIT) to detect faecal haemoglobin (Hb) in symptomatic people attending primary care in the context of the English NICE DG30 guidance.Materials and Methods: Data obtained from independent verification studies and clinical testing of the HM-JACKarc FIT method in routine primary care practice were analysed to derive performance characteristics.Results: Detection capabilities for the FIT method were 0.5 µg/g (limit of blank), 1.3 µg/g (limit of detection) and 3.0 µg/g (limit of quantitation). Of 33 non-homogenized specimens, 31 (93.9%) analysed in triplicate were consistently categorized relative to 10 µg/g, compared to all 33 (100%) homogenized specimens. Imprecision was higher (median 27.8%, (range 20.5% to 48.6%)) in non-homogenized specimens than in homogenized specimens (10.2%, (7.0 to 13.5%)). Considerable variation was observed in sequential clinical specimens from individual patients but no positive or negative trend in specimen degradation was observed over time (p = 0.26).Discussion: The FIT immunoassay evaluated is capable of detecting faecal Hb at concentrations well below the DG30 threshold of 10 µg/g and is suitable for application in this context. The greatest practical challenge to FIT performance is reproducible sampling, the pre-analytical step associated with most variability. Further research should focus on reducing sampling variability, particularly as post-COVID-19 guidance recommends greater FIT utilization.

Faecal immunochemical testing and blood tests for prioritization of urgent colorectal cancer referrals in symptomatic patients: a 2-year evaluation

BACKGROUND

A novel pathway incorporating faecal immunochemical testing (FIT) for rapid colorectal cancer diagnosis (RCCD) was introduced in 2017. This paper reports on the service evaluation after 2 years of pathway implementation.

METHODS

The RCCD protocol was based on FIT, blood results and symptoms to stratify adult patients in primary care. Two-week-wait (2WW) investigation was indicated for patients with rectal bleeding, rectal mass and faecal haemoglobin (fHb) level of 10 µg Hb/g faeces or above or 4 µg Hb/g faeces or more in the presence of anaemia, low ferritin or thrombocytosis, in all other symptom groups. Patients with 100 µg Hb/g faeces or above had expedited investigation . A retrospective audit of colorectal cancer detected between 2017 and 2019 was conducted, fHb thresholds were reviewed and critically assessed for cancer diagnoses.

RESULTS

In 2 years, 14788 FIT tests were dispatched with 13361 (90.4 per cent) completed returns. Overall, fHb was less than 4 µg Hb/g faeces in 9208 results (68.9 per cent), 4-9.9 µg Hb/g in 1583 (11.8 per cent), 10-99.9 µg Hb/g in 1850 (13.8 per cent) and 100 µg Hb/g faeces or above in 720 (5.4 per cent). During follow-up (median 10.4 months), 227 colorectal cancers were diagnosed. The cancer detection rate was 0.1 per cent in patients with fHb below 4 µg Hb/g faeces, 0.6 per cent in those with fHb 4-9.9 µg Hb/g faeces, 3.3 per cent for fHb 10-99.9 µg Hb/g faeces and 20.7 per cent for fHb 100 µg Hb/g faeces or above. The detection rate in the cohort with 10-19.9 µg Hb/g faeces was 1.4 per cent, below the National Institute for Health and Care Excellence threshold for urgent referral. The colorectal cancer rate in patients with fHb below 20 µg Hb/g faeces was less than 0.3 per cent.

CONCLUSION

Use of FIT to "rule out" urgent referral from primary care misses a small number of cases. The threshold for referral may be adjusted with blood results to improve stratification .

Quantitative FIT stratification is superior to NICE referral criteria NG12 in a high-risk colorectal cancer population

BACKGROUND

Guidelines for urgent investigation of colorectal cancer (CRC) are based on age and symptom-based criteria. This study aims to compare the diagnostic value of clinical features and faecal immunochemical test (FIT) results to identify those at a higher risk of CRC, thereby facilitating effective triage of patients.

METHODS

We undertook a review of all patients referred for investigation of CRC at our centre between September 2016 and June 2018. Patients were identified using a prospectively recorded local database. We performed a logistic regression analysis of factors associated with a diagnosis of CRC.

RESULTS

One-thousand-and-seven-hundred-eighty-four patients with FIT results were included in the study. Change in bowel habit (CIBH) was the most common referring clinical feature (38.3%). Patients diagnosed with CRC were significantly older than those without malignancy (74.0 years vs 68.9 years, p = 0.0007). Male patients were more likely to be diagnosed with CRC than females (6.5% vs 2.5%, Chi-squared 16.93, p < 0.0001). CRC was diagnosed in 3.5% (24/684) with CIBH compared to 8.1% (6/74) with both CIBH and iron deficiency anaemia. No individual or combination of referring clinical features was associated with an increased diagnosis of CRC (Chi-squared, 8.03, p = 0.155). Three patients with negative FIT results (< 4 µg Hb/g faeces) were diagnosed with CRC (3/1027, 0.3%). The highest proportion of cancers detected was in the ≥ 100 µg Hb/g faeces group (55/181, 30.4%).

CONCLUSION

In a multivariate model, FIT outperforms age, sex and all symptoms prompting referral. FIT has greater stratification value than any referral symptoms. FIT does have value in patients with iron deficiency anaemia.

Diagnosing colorectal cancer in primary care: cohort study in Sweden of qualitative faecal immunochemical tests, haemoglobin levels, and platelet counts

BACKGROUND

Colorectal cancer (CRC) diagnostics are challenging in primary care and reliable diagnostic aids are desired. Qualitative faecal immunochemical tests (FITs) have been used for suspected CRC in Sweden since the mid-2000s, but evidence regarding their effectiveness is scarce. Anaemia and thrombocytosis are both associated with CRC.

AIM

To evaluate the usefulness of qualitative FITs requested for symptomatic patients in primary care, alone and combined with findings of anaemia and thrombocytosis, in the diagnosis of CRC.

DESIGN AND SETTING

A population-based cohort study using electronic health records and data from the Swedish Cancer Register, covering five Swedish regions.

METHOD

Patients aged ≥18 years in the five regions who had provided FITs requested by primary care practitioners from 1 January 2015 to 31 December 2015 were identified. FIT and blood-count data were registered and all CRC diagnoses made within 2 years were retrieved. Diagnostic measurements were calculated.

RESULTS

In total, 15 789 patients provided FITs (four different brands); of these patients, 304 were later diagnosed with CRC. Haemoglobin levels were available for 13 863 patients, and platelet counts for 10 973 patients. Calculated for the different FIT brands only, the sensitivities for CRC were 81.6%-100%; specificities 65.7%-79.5%; positive predictive values 4.7%-8.1%; and negative predictive values 99.5%-100%. Calculated for the finding of either a positive FIT or anaemia, the sensitivities increased to 88.9-100%. Adding thrombocytosis did not further increase the diagnostic performance.

CONCLUSION

Qualitative FITs requested in primary care seem to be useful as rule-in tests for referral when CRC is suspected. A negative FIT and no anaemia indicate a low risk of CRC.

Choice of faecal immunochemical test matters: comparison of OC-Sensor and HM-JACKarc, in the assessment of patients at high risk of colorectal cancer

Objectives

Currently, NICE recommends the use of faecal immunochemical test (FIT) at faecal haemoglobin concentrations (f-Hb) of 10 μg Hb/g faeces to stratify for colorectal cancer (CRC) risk in symptomatic populations. This f-Hb cut-off is advised across all analysers, despite the fact that a direct comparison of analyser performance, in a clinical setting, has not been performed.

Methods

Two specimen collection devices (OC-Sensor, OC-S; HM-JACKarc, HM-J) were sent to 914 consecutive individuals referred for follow up due to their increased risk of CRC. Agreement of f-Hb around cut-offs of 4, 10 and 150 µg Hb/g faeces and CRC detection rates were assessed. Two OC-S devices were sent to a further 114 individuals, for within test comparisons.

Results

A total of 732 (80.1%) individuals correctly completed and returned two different FIT devices, with 38 (5.2%) CRCs detected. Median f-Hb for individuals diagnosed with and without CRC were 258.5 and 1.8 µg Hb/g faeces for OC-S and 318.1 and 1.0 µg Hb/g faeces for HM-J respectively. Correlation of f-Hb results between OC-S/HM-J over the full range was rho=0.74, p<0.001. Using a f-Hb of 4 µg Hb/g faeces for both tests found an agreement of 88.1%, at 10 µg Hb/g faeces 91.7% and at 150 µg Hb/g faeces 96.3%. A total of 114 individuals completed and returned two OC-S devices; correlation across the full range was rho=0.98, p<0.001.

Conclusions

We found large variations in f-Hb when different FIT devices were used, but a smaller variation when the same FIT device was used. Our data suggest that analyser-specific f-Hb cut-offs are applied with regard to clinical decision making, especially at lower f-Hb.

COVID-19 recovery: tackling the 2-week wait colorectal pathway backlog by optimising CT colonography utilisation

AIM

To review the indications for computed tomography colonography (CTC) performed on patients referred via the 2-week wait colorectal pathway (2WWCP).

MATERIALS AND METHODS

A retrospective study was performed on all patients referred through the 2WWCP between October 2018 and September 2019. The referrals were audited against the National Institute for Health and Care Excellence (NICE) NG12/DG30 guidelines for referral to the 2WWCP, and against the Royal College of Radiologists (RCR) 2017 guidelines for CTC.

RESULTS

Over the study period, there were 1,707 2WWCP referrals, and 362 (21.2%) of these patients underwent CTC. The median age was 66 years, and 55% were female. Forty-six patients did not meet the NICE NG12/DG30 guidelines for referral to the 2WWCP, and a further 268, although meeting the NICE guidelines, did not meet the RCR 2017 guidelines for CTC. In total, only 13% of CTCs performed complied with both guidelines.

CONCLUSION

This audit demonstrated a significant opportunity to reallocate CTC resources in the recovery stage of the COVID-19 pandemic. To improve outcomes for colorectal cancer (CRC) in the UK, establishing a selective straight-to-test CTC 2WWCP should be considered. Documented consent detailing the risks and benefits of CTC versus colonoscopy should take place in order to assist the patient in making an informed choice.

Service evaluation of faecal immunochemical testing introduced for use in North East London for patients at low risk of colorectal cancer

AIMS

Colorectal cancer (CRC) is the fourth most common cancer in the UK. Following National Institute of Clinical Excellence (NICE) guidance for faecal immunochemical testing (FIT) (DG30), we introduced a service for the measurement of faecal haemoglobin (fHb) in symptomatic patients in line with the 2017 update of the NG12 guidance. The purpose of this study was to audit the use of FIT, focussing on the indication for request and referral for diagnostic tests as recommended in NICE guidance.

METHODS

Testing was rolled out after careful introduction with extensive education led by the local Cancer Alliance and reinforced by the laboratory. After 6 months, the outcomes of all patients tested were reviewed.

RESULTS

1203 samples were received, of which 894 (74.3%) were suitable for analysis. Of these, 482 (53.9%) actually met the criteria for FIT analysis stipulated in our patient pathway. Eight patients were diagnosed with CRC; fHb was detectable in all and was ≥200 µg/g in seven and <10 µg/g in one. 217 patients underwent gastrointestinal investigations, and the sensitivity and specificity of FIT for CRC were found to be 87.5% (95% CI 46.6% to 99.7%) and 52.6% (95% CI 45.6% to 59.6%), respectively. Patients with anaemia were more likely to have fHb ≥10 µg/g.

CONCLUSIONS

These findings suggest benefits from the introduction of FIT in terms of more efficient use of diagnostic investigations, while revealing initial problems relating to familiarity with a new test. This merits further intervention with education and awareness programmes for Primary Care and further audit.

Thrombocytosis helps to stratify risk of colorectal cancer in patients referred on a 2-week-wait pathway

PURPOSE

Primary care studies suggest that thrombocytosis (platelet counts > 400 × 109/L) is associated with an increased risk of colorectal cancer (CRC). We aimed to establish whether this marker has significant stratification value in patients seen in secondary care.

METHODS

A retrospective review of 2991 patients referred to our colorectal 2-week-wait (2WW) pathway between August 2014 and August 2017. Patient demographics were recorded prospectively, and local electronic records systems were used to retrieve full blood counts (FBC) and cancer diagnoses. Patients with no recent platelet count at the time of referral or incomplete records were excluded.

RESULTS

2236 patients were included in this evaluation. There was no significant difference in the age distribution of those with thrombocytosis and those without. There were significantly more females in the thrombocytosis group (72.1% vs 53.9%, chi-squared 24.63, p < 0.0001). 130 CRCs were detected (5.8%) and patients with thrombocytosis were more likely to have CRC (OR 2.62, 95% CI 1.60-4.30). The CRC diagnosis rate was significantly higher in females with thrombocytosis (10.3% vs 2.9%, chi-squared 19.41, p < 0.0001) and males with thrombocytosis (16.1% vs 7.9%, chi-squared 4.62, p = 0.032).

CONCLUSION

Thrombocytosis appears to have stratification value in the 2WW population. Further evaluation of its value alone or in combination with other stratification tests is required.

Early clinical outcomes of a rapid colorectal cancer diagnosis pathway using faecal immunochemical testing in Nottingham

AIM

We introduced primary care access to faecal immunochemical testing (FIT) as a stratification tool for symptomatic patients considered to be at risk of colorectal cancer (CRC) prior to urgent referral. We aimed to evaluate clinical and pathway outcomes during the first 6 months of this novel approach.

METHOD

FIT was recommended for all patients who consulted their general practitioner with lower gastrointestinal symptoms other than rectal bleeding and rectal mass. We undertook a retrospective audit of the results of FIT, related clinical outcomes and resource utilization on prospectively logged cases between November 2017 and May 2018.

RESULTS

Of the 1862 FIT kits dispatched by post 91.4% were returned, with a median return time of 7 days (range 2-110 days); however, 1.3% of returned kits could not be analysed. FIT results ≥ 150.0 μg haemoglobin (Hb)/g faeces identified patients with a significantly higher risk of CRC (30.9% vs 1.4%, chi-square 167.1, P < 0.0001). FIT results ≥ 10.0 μg Hb/g faeces identified patients with significantly higher risk of significant noncancer bowel pathology (24.1% vs 4.9%, chi-square 73.6, P < 0.0001) and FIT results < 4.0 μg Hb/g faeces identified a group more likely to have non-CRC pathology (5.1% vs 2.4%, chi-square 3.9, P < 0.05). The CRC detection rate in 531 patients investigated after a FIT result of < 4.0 μg Hb/g faeces was 0.2%. In 899 investigated patients, a FIT result with a threshold of 4.0 μg Hb/g faeces had sensitivity 97.2% (85.5-99.9% CI), specificity 61.4% (58.1-64.7% CI), negative predictive value 99.8% (98.7-100.0% CI) and positive predictive value 9.5% (8.7-10.4% CI).

CONCLUSION

A symptomatic pathway incorporating FIT is feasible and appears more clinically effective than pathways based on age and symptoms alone.

Refinement and validation of the IDIOM score for predicting the risk of gastrointestinal cancer in iron deficiency anaemia

OBJECTIVE

To refine and validate a model for predicting the risk of gastrointestinal (GI) cancer in iron deficiency anaemia (IDA) and to develop an app to facilitate use in clinical practice.

DESIGN

Three elements: (1) analysis of a dataset of 2390 cases of IDA to validate the predictive value of age, sex, blood haemoglobin concentration (Hb), mean cell volume (MCV) and iron studies on the probability of underlying GI cancer; (2) a pilot study of the benefit of adding faecal immunochemical testing (FIT) into the model; and (3) development of an app based on the model.

RESULTS

Age, sex and Hb were all strong, independent predictors of the risk of GI cancer, with ORs (95% CI) of 1.05 per year (1.03 to 1.07, p<0.00001), 2.86 for men (2.03 to 4.06, p<0.00001) and 1.03 for each g/L reduction in Hb (1.01 to 1.04, p<0.0001) respectively. An association with MCV was also revealed, with an OR of 1.03 for each fl reduction (1.01 to 1.05, p<0.02). The model was confirmed to be robust by an internal validation exercise. In the pilot study of high-risk cases, FIT was also predictive of GI cancer (OR 6.6, 95% CI 1.6 to 51.8), but the sensitivity was low at 23.5% (95% CI 6.8% to 49.9%). An app based on the model was developed.

CONCLUSION

This predictive model may help rationalise the use of investigational resources in IDA, by fast-tracking high-risk cases and, with appropriate safeguards, avoiding invasive investigation altogether in those at ultra-low predicted risk.

The diagnostic accuracy of the faecal immunochemical test for colorectal cancer in risk-stratified symptomatic patients

INTRODUCTION

The faecal immunochemical test detects blood in the faeces, reporting faecal haemoglobin quantitatively in micrograms of haemoglobin per gram of faeces. The aim of this pilot study was to determine the feasibility of using the faecal immunochemical test as a rule-out test in symptomatic patients at low and high risk of colorectal cancer.

MATERIAL AND METHODS

Between November 2016 and October 2017, consecutive symptomatic patients within a multicultural part of London were recruited to perform a faecal immunochemical test prior to colonoscopy. Analysis was performed on the HM-JACKarc analyser.

RESULTS

Faecal immunochemical test samples were returned by 298 patients who underwent colonoscopy. There was no significant variation in faecal haemoglobin levels by age, sex, ethnicity or deprivation. The overall detection rate for colorectal cancer was 100% at 2 µg/g and 92% at 10 µg/g. If a faecal haemoglobin threshold for investigation of 2 µg/g (ie detectable) or 10 µg/g had been employed, the number of colonoscopies would have been reduced by 70% and 84%, respectively, in all symptomatic patients. For low-risk patients, the sensitivity of the faecal immunochemical test for colorectal cancer at both thresholds of 2 µg/g or 10 µg/g remained 100%, with the number of colonoscopies reduced by 80% and 91%, respectively.

CONCLUSION

This study shows that the faecal immunochemical test is a promising technology that detected colorectal cancer in all high- or low-risk symptomatic patients in our cohort at a threshold of detectable faecal haemoglobin. Data from adequately powered cohort studies will elucidate the true diagnostic accuracy of the test and the rate and patterns of undetected colorectal cancer.

Recent advances in colonoscopy

Colonoscopy continues to evolve as equipment and techniques improve. Traditionally, colonoscopy has focused on adenoma detection, characterisation and resection as the primary aims, and there has certainly been considerable activity over the last few years in terms of addressing these important issues. This review article not only will discuss progress made in these areas but also will focus on when to colonoscope in terms of introduction of faecal immunochemical testing, how to insert with the advent of water-assisted insertion, and how to withdraw using a bundle of evidence-based techniques to improve adenoma detection. In addition, the ramifications of failing to discover polyps and of post-colonoscopy colorectal cancer are highlighted.