The repeat FIT (RFIT) study: Does repeating faecal immunochemical tests provide reassurance and improve colorectal cancer detection?

AIM: Faecal immunochemical tests (FIT) are highly sensitive for colorectal cancer (CRC) detection. Little evidence exists regarding repeat FIT. The repeat FIT (RFIT) study aimed to determine whether second and third FIT provide reassurance and improve CRC or significant bowel disease (SBD) identification. METHODS: This was a prospective observational study. Patients recruited from urgent referrals returned three FIT and underwent colonoscopy. Chi-square tests compared categorical data. Diagnostic accuracy variables (sensitivity/specificity/positive predictive value [PPV]/negative predictive value [NPV]) were calculated for one, two and three FIT (95% CI). Three negative FIT (<10 µg Hb/g of faeces [µg/g]) groups (one, two, three) were compared with positive groups (one or more FIT ≥10 µg/g). CRC and SBD detection rates were compared by strategy. RESULTS: A total of 460 patients (mean age: 66.8 years, 233 males and 227 females, 23 CRC, 80 SBD) were included in the study. For one, two and three negative FIT, CRC sensitivity remained static (95.7%); specificity (44.6%, 40.7% and 38.4%) and NPV decreased (99.5%, 99.4% and 99.4%). For SBD, sensitivity increased (78.8%, 83.8% and 86.3%), specificity decreased (47.4%, 43.7% and 41.6%) and NPV increased (91.4%, 92.7% and 93.5%). In one, two and three positive FIT groups, CRC detection was 8.3%,16.1% and 20.9%. CRC mean FIT was 150 µg/g, <6 µg/g for benign pathology. CONCLUSIONS: One or more negative FIT increases the sensitivity for CRC/SBD. Repeating FIT provides greater differentiation of patients with and without CRC/SBD compared to single FIT but is associated with decreased specificity and PPV. Multiple negative FIT may offer reassurance; however, application of repeating FIT may be restricted given the associated increase in investigations.

Faecal immunochemical tests can improve colonoscopy triage in patients with iron deficiency: A systematic review and meta-analysis.

BACKGROUND: Use of the faecal immunochemical test (FIT) to triage patients with iron deficiency (ID) for colonoscopy due to suspected colorectal cancer (CRC) may improve distribution of colonoscopic resources. We reviewed the diagnostic performance of FIT for detecting advanced colorectal neoplasia, including CRC and advanced pre-cancerous neoplasia (APCN), in patients with ID, with or without anaemia. METHODS: We performed a systematic review of three databases for studies comprising of patients with ID, with or without anaemia, completing a quantitative FIT within six months prior to colonoscopy, where test performance was compared against the reference standard colonoscopy. Random effects meta-analyses determined the diagnostic performance of FIT for advanced colorectal neoplasia. RESULTS: Nine studies were included on a total of n=1761 patients with ID, reporting FIT positivity thresholds between 4-150 µg haemoglobin/g faeces. Only one study included a non-anaemic ID (NAID) cohort. FIT detected CRC and APCN in ID patients with 90.7 % and 49.3 % sensitivity, and 81.0 % and 82.4 % specificity, respectively. FIT was 88.0 % sensitive and 83.4 % specific for CRC in patients with ID anaemia at a FIT positivity threshold of 10 µg haemoglobin/g faeces. CONCLUSIONS: FIT shows high sensitivity for advanced colorectal neoplasia and may be used to triage those with ID anaemia where colonoscopic resources are limited, enabling those at higher risk of CRC to be prioritised for colonoscopy. There is a need for further research investigating the diagnostic performance of FIT in NAID patients.

The impact of primary-care led, faecal immunochemical test-based, triage of new-onset colorectal symptoms on time to diagnosis of colorectal cancer-An observational study.

AIM: Since December 2015, a faecal immunochemical test (FIT) has been provided to primary care in NHS Tayside as an adjunct to clinical acumen in the assessment of new-onset bowel symptoms. The aim of this work was to assess the impact of this approach on time to diagnosis of colorectal cancer (CRC). METHOD: NHS Tayside Cancer audit data from January 2013 to December 2019 were reviewed to identify all CRC patients diagnosed via the primary-care referral pathway for a period before and after the introduction of FIT. Their electronic patient records were accessed and date of referral and any contemporaneous FIT and full blood count (FBC) result were recorded. Time from referral to diagnosis of CRC was calculated for each patient and compared between subgroups. RESULTS: The study cohort consisted of 959 patients: 378 and 581 from the time periods before and after the introduction of FIT, respectively. The median time to diagnosis before FIT was 30 days [interquartile range (IQR) 16-57 days] versus 25 days (IQR 14-47 days) following the introduction of FIT (p = 0.006). Following the introduction of FIT, patients who completed a FIT had a median of time to diagnosis of 23 days (IQR 14-43 days) compared with 30 days (IQR 16-62 days) for patients not completing a FIT (p = 0.019). FBC results were available for 97.5% of FIT patients to aid safety-netting of patients with a low or undetectable faecal haemoglobin concentration. CONCLUSION: The introduction of FIT-based triage of new bowel symptoms in primary care as an adjunct to clinical acumen is associated with a reduced time to CRC diagnosis.

Next-Generation Multitarget Stool DNA Test for Colorectal Cancer Screening.

BACKGROUND: A next-generation multitarget stool DNA test, including assessments of DNA molecular markers and hemoglobin level, was developed to improve the performance of colorectal cancer screening, primarily with regard to specificity. METHODS: In a prospective study, we evaluated a next-generation multitarget stool DNA test in asymptomatic adults 40 years of age or older who were undergoing screening colonoscopy. The primary outcomes were sensitivity of the test for colorectal cancer and specificity for advanced neoplasia (colorectal cancer or advanced precancerous lesions). Advanced precancerous lesions included one or more adenomas or sessile serrated lesions measuring at least 1 cm in the longest dimension, lesions with villous histologic features, and high-grade dysplasia. Secondary objectives included the quantification of sensitivity for advanced precancerous lesions and specificity for nonneoplastic findings or negative colonoscopy and comparison of sensitivities for colorectal cancer and advanced precancerous lesions between the multitarget stool DNA test and a commercially available fecal immunochemical test (FIT). RESULTS: Of 20,176 participants, 98 had colorectal cancer, 2144 had advanced precancerous lesions, 6973 had nonadvanced adenomas, and 10,961 had nonneoplastic findings or negative colonoscopy. With the next-generation test, sensitivity for colorectal cancer was 93.9% (95% confidence interval [CI], 87.1 to 97.7), and specificity for advanced neoplasia was 90.6% (95% CI, 90.1 to 91.0). Sensitivity for advanced precancerous lesions was 43.4% (95% CI, 41.3 to 45.6), and specificity for nonneoplastic findings or negative colonoscopy was 92.7% (95% CI, 92.2 to 93.1). With the FIT, sensitivity was 67.3% (95% CI, 57.1 to 76.5) for colorectal cancer and 23.3% (95% CI, 21.5 to 25.2) for advanced precancerous lesions; specificity was 94.8% (95% CI, 94.4 to 95.1) for advanced neoplasia and 95.7% (95% CI, 95.3 to 96.1) for nonneoplastic findings or negative colonoscopy. As compared with FIT, the next-generation test had superior sensitivity for colorectal cancer (P<0.001) and for advanced precancerous lesions (P<0.001) but had lower specificity for advanced neoplasia (P<0.001). No adverse events occurred. CONCLUSIONS: The next-generation multitarget stool DNA test showed higher sensitivity for colorectal cancer and advanced precancerous lesions than FIT but also showed lower specificity. (Funded by Exact Sciences; BLUE-C ClinicalTrials.gov number, NCT04144738.).

Usefulness of an RNA extraction-free test for the multiplexed detection of ALK, ROS1, and RET Gene Fusions in Real Life FFPE Specimens of Non-Small Cell Lung Cancers.

BACKGROUND: ALK, ROS1 and RET rearrangements occur, respectively, in 5%, 2%, and 1% non-small cell lung cancers (NSCLC). ALK and ROS1 fusion proteins detection by immunohistochemistry (IHC) has been validated for rapid patient screening, but ROS1 fusions need to be confirmed by another technique and no RET IHC test is available for clinical use. RESEARCH DESIGN AND METHODS: We report herein the usefulness of the HTG EdgeSeq Assay, an RNA extraction-free test combining a quantitative nuclease protection assay with NGS, for the detection of ALK, ROS1 and RET fusions from 'real-life' small NSCLC samples. A total of 203 FFPE samples were collected from 11 centers. They included 143 rearranged NSCLC (87 ALK, 39 ROS1, 17 RET) and 60 ALK-ROS1-RET negative controls. RESULTS: The assay had a specificity of 98% and a sensitivity for ALK, ROS1 and RET fusions of 80%, 94% and 100% respectively. Among the 19 HTG-assay false negative samples, the preanalytical conditions were identified as the major factors impacting the assay efficiency. CONCLUSIONS: Overall, the HTG EdgeSeq assay offers comparable sensitivities and specificity than other RNA sequencing techniques, with the advantage that it can be used on very small and old samples collected multicentrically.

Splicing factor arginine/serine-rich 8 promotes multiple myeloma malignancy and bone lesion through alternative splicing of CACYBP and exosome-based cellular communication.

BACKGROUND: Multiple myeloma (MM) is a distinctive malignancy of plasma cell within the bone marrow (BM), of which alternative splicing factors play vital roles in the progression. Splicing factor arginine/serine-rich 8 (SFRS8) is the exclusive factor associated with MM prognosis, however its role in MM remains undefined. METHODS: The analyses of 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide (MTT) assay, immunohistochemistry, flow cytometry and xenograft model were performed to examine cell proliferation, cell cycle and apoptosis in SFRS8 overexpression or knockdown MM cells in vitro and in vivo. The SFRS8-regulated alternative splicing events were identified by RNA immunoprecipitation sequencing (RIP-seq) and validated by RIP-qPCR and Co-IP methods. Exosomes were extracted from the supernatant of myeloma cells by ultracentrifugation. Bone lesion was evaluated by TRAP staining in vitro and SCID/NOD-TIBIA mouse model. A neon electroporation system was utilised to deliver siRNA through exosomes. The effect of siRNA-loaded exosomes in vivo was evaluated by using a patient-derived tumor xenograft (PDX) model and SCID/NOD-TIBIA mouse model. RESULTS: SFRS8 was significantly upregulated in MM samples and positively associated with poor overall survival (OS) in MM patients. SFRS8 promoted MM cell proliferation in vitro and in vivo. Furthermore, calcyclin binding protein (CACYBP) was identified as the downstream target of SFRS8. Particularly, SFRS8 could reduce CACYBP isoform1 (NM_014412.3) and increase CACYBP isoform2 (NM_001007214.1) by mediating the alternative splicing of CACYBP, thereby altering the ubiquitination degradation of ß-catenin to promote MM progression. In addition, SFRS8 promoted osteoclast differentiation through exosomes in vitro and in vivo. More importantly, exosomal siRNA targeting CACYBP isoform2 inhibited tumour growth in PDX and SCID/NOD-TIBIA mouse models. CONCLUSION: Our findings demonstrate that targeting the SFRS8/CACYBP/ß-catenin axis may be a promising strategy for MM diagnosis and treatment.

Socioeconomic differences in participation and diagnostic yield within the Dutch national colorectal cancer screening programme with faecal immunochemical testing.

BACKGROUND: CRC mortality rates are higher for individuals with a lower socioeconomic status (SES). Screening could influence health inequalities. We therefore aimed to investigate SES differences in participation and diagnostic yield of FIT screening. METHODS: All invitees in 2014 and 2015 in the Dutch national CRC screening programme were included in the analyses. We used area SES as a measure for SES and divided invitees into quintiles, with Quintile 1 being the highest SES. Logistic regression analysis was used to compare the participation rate, positivity rate, colonoscopy uptake, positive predictive value (PPV) and detection rate across the SES groups. RESULTS: Participation to FIT screening was significantly lower for Quintile 5 (67.0%) compared to the other Quintiles (73.0% to 75.1%; adjusted OR quintile 5 versus quintile 1: 0.73, 95%CI: 0.72-0.74), as well as colonoscopy uptake after a positive FIT (adjusted OR 0.73, 95%CI: 0.69-0.77). The detection rate per FIT participant for advanced neoplasia gradually increased from 3.3% in Quintile 1 to 4.0% in Quintile 5 (adjusted OR 1.20%, 95%CI 1.16-1.24). As a result of lower participation, the yield per invitee was similar for Quintile 5 (2.04%) and Quintile 1 (2.00%), both being lower than Quintiles 2 to 4 (2.20%-2.28%). CONCLUSIONS: Screening has the potential to reduce health inequalities in CRC mortality, because of a higher detection in participants with a lower SES. However, in the Dutch screening programme, this is currently offset by the lower participation in this group.

A validation study of potential prognostic DNA methylation biomarkers in patients with acute myeloid leukemia using a custom DNA methylation sequencing panel.

BACKGROUND: Multiple studies have reported the prognostic impact of DNA methylation changes in acute myeloid leukemia (AML). However, these epigenetic markers have not been thoroughly validated and therefore are still not considered in clinical practice. Hence, we aimed to independently verify results of selected studies describing the relationship between DNA methylation of specific genes and their prognostic potential in predicting overall survival (OS) and event-free survival (EFS). RESULTS: Fourteen studies (published 2011-2019) comprising of 27 genes were subjected to validation by a custom NGS-based sequencing panel in 178 newly diagnosed non-M3 AML patients treated by 3 + 7 induction regimen. The results were considered as successfully validated, if both the log-rank test and multivariate Cox regression analysis had a p-value ≤ 0.05. The predictive role of DNA methylation was confirmed for three studies comprising of four genes: CEBPA (OS: p = 0.02; EFS: p = 0.03), PBX3 (EFS: p = 0.01), LZTS2 (OS: p = 0.05; EFS: p = 0.0003), and NR6A1 (OS: p = 0.004; EFS: p = 0.0003). For all of these genes, higher methylation was an indicator of longer survival. Concurrent higher methylation of both LZTS2 and NR6A1 was highly significant for survival in cytogenetically normal (CN) AML group (OS: p < 0.0001; EFS: p < 0.0001) as well as for the whole AML cohort (OS: p = 0.01; EFS < 0.0001). In contrast, for two studies reporting the poor prognostic effect of higher GPX3 and DLX4 methylation, we found the exact opposite, again linking higher GPX3 (OS: p = 0.006; EFS: p < 0.0001) and DLX4 (OS: p = 0.03; EFS = 0.03) methylation to a favorable treatment outcome. Individual gene significance levels refer to the outcomes of multivariate Cox regression analysis. CONCLUSIONS: Out of twenty-seven genes subjected to DNA methylation validation, a prognostic role was observed for six genes. Therefore, independent validation studies are necessary to reveal truly prognostic DNA methylation changes and to enable the introduction of these promising epigenetic markers into clinical practice.

Immunoexpression of PTEN, HER2/neu, and Ki-67 in endoscopic gastric carcinoma biopsies; their correlation with histological subtypes and one-year survival.

BACKGROUND: Gastric carcinoma is a major cause of cancer-related morbidity and mortality worldwide. Gastric neoplasms arise from genetic and epigenetic changes in various genes. Present study evaluates the immunoexpression of PTEN, HER2/neu, and Ki-67 in endoscopic gastric carcinoma biopsies and correlates the expression of these proteins with clinicopathological features. MATERIAL AND METHODS: Adequate endoscopic biopsies of 27 cases of gastric carcinoma were evaluated for World Health Organization (WHO) and Lauren's classification subtypes along with HER2/neu, PTEN, and Ki-67 immunoexpression. HER2/neu immunostaining was scored as proposed in the Trastuzumab for gastric cancer (ToGA) trial while PTEN staining and downregulation were assessed using an immunoreactive score. The cut-off for Ki-67 expression was taken as 90th percentile of the values in adjacent non-neoplastic tissue. All statistical analysis was done at 5% level of significance with SPSS v22 statistical software. RESULTS: Tubular adenocarcinoma was the commonest WHO histological subtype and 56% of cases were of intestinal type as per Lauren's classification. 55.6% of cases showed a complete loss of PTEN expression in neoplastic tissue. 17 of the 19 cases with adjacent non-neoplastic tissue showed PTEN downregulation in neoplastic tissue. 81.5% of cases had a high Ki-67 index and HER2/neu overexpression was noted in 36% of cases. All the four cases who died had high Ki-67 proliferation indices; 3 patients had loss of PTEN expression and HER2/neu overexpression. CONCLUSION: We conclude that these immunomarkers can play important role in the behavior of gastric carcinomas and can be targeted for new therapies.

Chemical strategies for triggering the immune response to the mycotoxin patulin.

Mycotoxins represent a major concern for human and animal health because of their harmful effects and high occurrence in food and feed. Rapid immunoanalytical methods greatly contribute to strengthening the safety of our food supply by efficiently monitoring chemical contaminants, so high-affinity and specific antibodies have been generated for almost all internationally regulated mycotoxins. The only exception is patulin, a mycotoxin mainly produced by Penicillium expansum for which such a target has not yet been achieved. Accordingly, no point-of-need tests commonly used in food immunodiagnostics are commercially available for patulin. In the present study, three functionalized derivatives conforming to generally accepted rules in hapten design were firstly tested to generate suitable antibodies for the sensitive immunodetection of patulin. However, these conventional bioconjugates were unable to elicit the desired immune response, so an alternative strategy that takes advantage of the high electrophilic reactivity of patulin was explored. Patulin was reacted with 4-bromothiophenol, and the obtained adduct was used to produce antibodies with nanomolar affinity values. These results demonstrated for the first time that targeting the adduct resulting from the reaction of patulin with a thiol-containing compound is a promising approach for developing user-friendly immunoanalytical techniques for this elusive mycotoxin.

The New Generation Immunochemical Test for Fecal Occult Blood (ColonView Quick Test) Shows a High Diagnostic Accuracy in Colorectal Cancer Detection.

BACKGROUND/AIM: The present study compared the accuracy of visually analyzed (VA) and automatically analyzed (AA) ColonView (CV) quick test; a new-generation immunochemical test (FIT) for Hb and Hb/Hp (Biohit Oyj, Helsinki, Finland) in subjects participating in colorectal cancer (CRC) detection in Brazil. A traditional gFOBT test (HemoccultSENSA) was used as a reference. PATIENTS AND METHODS: A cohort of 368 colonoscopy-referral patients were asked to collect 3 consecutive fecal samples, to be analysed by both assays (CV, SENSA). RESULTS: In receiver operating characteristic (ROC) analysis for the AA reading, the optimal cut-off value for CV Hb AA (test AA 3) was ≥117 and that for CV Hb/Hp AA (test AA 4) was ≥48. In the hierarchical summary receiver operating characteristic (HSROC) analysis for pooled accuracy of CV with AA and VA reading, the AUC values for i) VA and ii) AA were as follows: i) AUC=0.859 (95%CI=0.839-0.879), ii) AUC=0.931 (95%CI=0.920-0.942). The difference between these AUC values (Roccomp analysis) was statistically significant (p=0.0024). CONCLUSION: The present study confirms the previous studies on the applicability of the ColonView quick test (a new-generation FIT) in CRC screening.

Significant decrease in interval colorectal cancer incidence after implementing immunochemical testing in a multiple-round guaiac-based screening programme.

BACKGROUND AND AIMS: We aimed to evaluate the effects of switching to faecal immunochemical testing (FIT) on the cumulative 2-year incidence rate of interval cancers, interval cancer rate and test sensitivity within a mature population-based colorectal cancer screening programme consisting of six rounds of biennial guaiac faecal occult blood testing (gFOBT). METHODS: The FIT results were compared with those of gFOBT used in each of the previous two rounds. For the three rounds analysed, 279,041 tests were performed by 156,186 individuals. Logistic regression analysis was used to determine interval cancer risk factors (Poisson regression) and to compare the sensitivity of FIT to gFOBT. RESULTS: There were 612 cases of screen-detected cancers and 209 cases of interval cancers. The sex- and age-adjusted cumulative 2-year incidence rates of interval cancers were 55.7 (95% CI, 45.3-68.5), 42.4 (95% CI, 32.6-55.2) and 15.8 (95% CI, 10.9-22.8) per 100,000 person-years after the last two rounds of gFOBT and FIT, respectively. The FIT/gFOBT incidence rate ratio was 0.38 [95% CI, 0.27-0.54] (P < 0.001). Sex- and age-adjusted sensitivity was significantly higher with FIT than with gFOBT (OR = 6.70 [95% CI, 4.48-10.01], P < 0.0001). CONCLUSIONS: This population-based study revealed a dramatic decrease in the cumulative incidence rates of interval cancers after switching from gFOBT to FIT. These data provide an additional incentive for countries still using gFOBT to switch to FIT.

Antisense Peptide Technology for Diagnostic Tests and Bioengineering Research.

Antisense peptide technology (APT) is based on a useful heuristic algorithm for rational peptide design. It was deduced from empirical observations that peptides consisting of complementary (sense and antisense) amino acids interact with higher probability and affinity than the randomly selected ones. This phenomenon is closely related to the structure of the standard genetic code table, and at the same time, is unrelated to the direction of its codon sequence translation. The concept of complementary peptide interaction is discussed, and its possible applications to diagnostic tests and bioengineering research are summarized. Problems and difficulties that may arise using APT are discussed, and possible solutions are proposed. The methodology was tested on the example of SARS-CoV-2. It is shown that the CABS-dock server accurately predicts the binding of antisense peptides to the SARS-CoV-2 receptor binding domain without requiring predefinition of the binding site. It is concluded that the benefits of APT outweigh the costs of random peptide screening and could lead to considerable savings in time and resources, especially if combined with other computational and immunochemical methods.

Nanoscale spatial dependence of avidity in an IgG1 antibody.

Antibodies are secreted proteins that are crucial to recognition of pathogens by the immune system and are also efficient pharmaceuticals. The affinity and specificity of target recognition can increase remarkably through avidity effects, when the antibody can bind a multivalent antigen through more than one epitope simultaneously. A key goal of antibody engineering is thus to optimize avidity, but little is known about the nanoscale spatial dependence of avidity in antibodies. Here, we develop a set of anti-parallel coiled-coils spanning from 7 to 20 nm and validate their structure using biophysical techniques. We use the coiled-coils to control the spacing between two epitopes, and measure how antigen spacing affects the stability of the bivalent antibody:antigen complex. We find a maximal avidity enhancement at a spacing of 13 nm. In contrast to recent studies, we find the avidity to be relatively insensitive to epitope spacing near the avidity maximum as long as it is within the spatial tolerance of the antibody. We thus only see a ~ twofold variation of avidity in the range from 7 to 20 nm. The coiled-coil systems developed here may prove a useful protein nanocaliper for profiling the spatial tolerance and avidity profile of bispecific antibodies.

Multitarget Stool RNA Test for Noninvasive Detection of Colorectal Neoplasias in a Multicenter, Prospective, and Retrospective Cohort.

INTRODUCTION: Effective colorectal cancer (CRC) prevention and screening requires sensitive detection of all advanced neoplasias (CRC and advanced adenomas [AA]). However, existing noninvasive screening approaches cannot accurately detect adenomas with high sensitivity. METHODS: Here, we describe a multifactor assay (RNA-FIT test) that combines 8 stool-derived eukaryotic RNA biomarkers, patient demographic information (smoking status), and a fecal immunochemical test (FIT) to sensitively detect advanced colorectal neoplasias and other non-advanced adenomas in a 1,305-patient, average-risk, prospective cohort. This cohort was supplemented with a 22-patient retrospective cohort consisting of stool samples obtained from patients diagnosed with AA or CRC before treatment or resection. Participants within these cohorts were evaluated with the RNA-FIT assay and an optical colonoscopy. RNA-FIT test results were compared with colonoscopy findings. RESULTS: Model performance was assessed through 5-fold internal cross-validation of the training set (n = 939) and by using the model on a hold out testing set (n = 388). When used on the hold out testing set, the RNA-FIT test attained a 95% sensitivity for CRC (n = 22), 62% sensitivity for AA (n = 52), 25% sensitivity for other non-AA (n = 139), 80% specificity for hyperplastic polyps (n = 74), and 85% specificity for no findings on a colonoscopy (n = 101). DISCUSSION: The RNA-FIT assay demonstrated clinically relevant detection of all grades of colorectal neoplasia, including carcinomas, AAs, and ONAs. This assay could represent a noninvasive option to screen for both CRC and precancerous adenomas.

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 .

Use of faecal immunochemical testing as an alternative to faecal calprotectin in children.

BACKGROUND: Faecal calprotectin has been widely used as a non-invasive marker of intestinal inflammation in children. Measurement of faecal haemoglobin using faecal immunochemical test is well established in adults for detection of colorectal cancer. In adults, faecal haemoglobin has been recommended as a reliable tool to aid identification of those at low risk of significant bowel disease and has also been used in inflammatory bowel disease to assess mucosal healing. AIMS: We aimed to evaluate the performance of faecal haemoglobin in the paediatric population and compare it with faecal calprotectin. METHODS: Children being assessed in the paediatric gastroenterology clinic for bowel symptoms had a sample sent for both faecal calprotectin and faecal haemoglobin. Samples were collected over a 10-month period from November 2018 to September 2019. Faecal haemoglobin was measured using an OC-Sensor. Faecal calprotectin was measured using Liason®Calprotectin. RESULTS: One hundred forty three samples were returned for faecal haemoglobin and in 107 a paired faecal calprotectin was also available. Faecal haemoglobin correlated with faecal calprotectin, Spearman's rank coefficient 0.656 (P < 0.0001). There were 35 patients with faecal haemoglobin >20 µg/g and in 32 of these patients faecal calprotectin was >200 µg/g; 74 patients with faecal haemoglobin and 38 patients with faecal calprotectin underwent colonoscopy. Patients with normal histology had faecal haemoglobin <4 µg/g; faecal haemoglobin >20 µg/g was associated with signification inflammation. CONCLUSION: Our study is the first to compare faecal haemoglobin and faecal calprotectin in a paediatric population. Results suggest that faecal haemoglobin correlates with faecal calprotectin and, as in adults, may be useful to rule out significant bowel disease. A faecal haemoglobin >20 µg/g was consistent with significant histological inflammation.