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Objective There is evidence that colorectal cancer screening using faecal haemoglobin is less effective in women than men. The faecal haemoglobin concentrations were therefore examined in women and men with screen-detected colorectal cancer. Setting Scottish Bowel Screening Programme, following the introduction of a faecal immunochemical test from November 2017, to March 2020. Methods Data were collated on faecal haemoglobin concentrations, pathological stage and anatomical site of the main lesion in participants who had colorectal cancer detected. The data in women and men were compared. Results For the faecal haemoglobin concentrations studied (>80 µg Hb/g faeces), the distributions indicated lower concentrations in women. Marked differences were found between women and men diagnosed with colorectal cancer. The median faecal haemoglobin concentration for women ( n = 720) was 408 µg Hb/g faeces compared to 473 µg Hb/g faeces for men ( n = 959) ( p = 0.004) and 50.6% of the results were >400 µg Hb/g faeces in women; in men, this was 57.8%. The difference in faecal haemoglobin concentrations in women and men became less statistically significant as stage advanced from stages I–IV. For right-sided, left-sided and rectal colorectal cancer, a similar gender difference persisted in all sites. Differences in faecal haemoglobin between the genders were significant for left-sided cancers and stage I and approached significance for rectal cancers and stage II, but all sites and stages showed lower median faecal haemoglobin concentrations for women. Conclusions To minimise gender inequalities, faecal immunochemical test-based colorectal cancer screening programmes should evaluate a strategy of using different faecal haemoglobin concentration thresholds in women and men.

Background Faecal haemoglobin concentration (f-Hb), estimated using a faecal immunochemical test, can be safely implemented in primary care to assess risk of colorectal cancer (CRC). Clinical outcomes of patients presenting with symptoms of lower gastrointestinal disease were examined using an extensive range of f-Hb thresholds to decide on reassurance or referral for further investigation. Methods All patients who attended primary care and submitted a single faecal specimen faecal immunochemical test in the first year of the routine service had f-Hb estimated using HM-JACKarc: f-Hb thresholds from Results Low f-Hb thresholds of 400 µg/g, ≥200 µg/g and ≥100 µg/g. However, patients with a f-Hb concentration of Conclusions In primary care, f-Hb, in conjunction with clinical assessment, can safely and objectively determine individual risk of CRC and decide on simple reassurance or urgent, or routine referral.

Background Quantitative faecal immunochemical tests measure faecal haemoglobin concentration (f-Hb), which increases in the presence of colorectal neoplasia. Objective We examined the diagnostic accuracy of faecal immunochemical test (FIT)in patients at increased risk of colorectal cancer (CRC) attending for surveillance colonoscopy as per national guidelines. Methods A total of 1103 consecutive patients were prospectively invited to complete a FIT before their scheduled colonoscopy in two university hospitals in 2014– 2016. F-Hb was analysed on an OC-Sensor io automated analyser (Eiken Chemical Co., Ltd, Tokyo, Japan) with a limit of detection of 2 µg Hb/g faeces. The diagnostic accuracy of f-Hb for CRC and higher-risk adenoma was examined. Results A total of 643 patients returned a faecal test. After excluding 4 patients with known inflammatory bowel disease, 639 (57.9%) remained in the study: age range: 25–90 years (median: 64 years, interquartile range (IQR): 55–71): 54.6% male. Of 593 patients who also completed colonoscopy, 41 (6.9%) had advanced neoplasia (4 CRC, 37 higher-risk adenoma). Of the 238 patients (40.1%) who had detectable f-Hb, 31 (13.0%) had advanced neoplasia (2 CRC, 29 higher-risk adenoma) compared with 10 (2.8%) in those with undetectable f-Hb (2 CRC, 8 higher-risk adenoma). Detectable f-Hb gave negative predictive values of 99.4% for CRC and 97.2% for CRC plus higher-risk adenoma. Conclusion In patients at increased risk of CRC under colonoscopy surveillance, a test measuring faecal haemoglobin can provide an objective estimate of the risk of advanced neoplasia, and could enable tailored scheduling of colonoscopy.

Background Current guidelines document persistent rectal bleeding as an alarm symptom in patients presenting to primary care. We studied whether a faecal immunochemical test could assist in their assessment. Methods From December 2015, faecal immunochemical tests were routinely available to primary care when assessing patients with new-onset bowel symptoms: general practitioners were encouraged to include faecal haemoglobin concentration (f-Hb) within any referral to secondary care. Results with f-Hb ≥10 μg Hb/g faeces were defined as positive. The incidence of significant bowel disease (SBD: colorectal cancer [CRC], higher-risk adenoma [HRA: any ≥1 cm, or three or more] and inflammatory bowel disease [IBD]) at subsequent colonoscopy, referred symptoms and f-Hb were recorded. Results Of 1447 patients with a faecal immunochemical test result and colonoscopy outcome, SBD was diagnosed in 296 patients (20.5%; 95 with CRC, 133 with HRA, and 68 with IBD). Four hundred and sixty-two patients (31.9%) reported rectal bleeding: 294 had f-Hb ≥10 μg Hb/g faeces. At colonoscopy, 105/294 had SBD versus 14/168 with rectal bleeding and f-Hb Conclusion Patients with rectal bleeding and f-Hb

Background There is currently no existing evidence on the effects of personalised risk information on uptake of colonoscopy following first line screening for colorectal cancer. This study aimed to measure the impact of providing risk information based on faecal haemoglobin concentration to allow a fully informed choice around whether or not to undergo colonoscopy. Methods Two thousand seven hundred sixty-seven participants from the Scottish Bowel Screening Programme (SBoSP) database, who had not recently been invited for screening, were randomised to receive one of three types of hypothetical risk information materials: (1) numerical risk information (risk categories of one in 40, one in 1600 and one in 3500), (2) categorical risk information (highest, moderate and lowest risk), or (3) positive screening result letter (control group). The primary outcome was the impact of the risk materials on intention to undergo colonoscopy, to allow comparison with the current colonoscopy uptake of 77% for those with a positive screening result in the SBoSP. Secondary outcomes were knowledge, attitudes and emotional responses to the materials. Results Four hundred thirty-four (15.7%) agreed to participate with 100 from the numerical risk group (69.0%), 104 from the categorical risk group (72.2%) and 104 from the control group (71.7%) returning completed materials. Intention to undergo colonoscopy was highest in the highest risk groups for the numerical and categorical study arms (96.8% and 95.3%, respectively), but even in the lowest risk groups was > 50% (58.1% and 60.7%, respectively). Adequate knowledge of colorectal screening and the risks and benefits of colonoscopy was found in ≥ 98% of participants in all three arms. All participants reported that they found the information easy-to-understand. 19.1%, 24.0% and 29.6% of those in the numerical, categorical and control group, respectively, reported that they found the information distressing (p > 0.05). Conclusions Applying the risk categories to existing SBoSP data shows that if all participants were offered an informed choice to have colonoscopy, over two thirds of participants would intend to have the test. Equating to an increase in the number of screening colonoscopies from approx. 14,000 to 400,000 per annum, this would place an unmanageable demand on colonoscopy services, with a very small proportion of cancers and pre-cancers detected. However, the response to the materials were very positive, suggesting that providing risk information to those in lowest and moderate risk groups along with advice that colonoscopy is not currently recommended may be an option. Future research would be required to examine actual uptake. Trial registration Date applied 1 December 2017 ISRCTN number 14254582.

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

Prediction models for colorectal cancer (CRC) detection in symptomatic patients, based on easily obtainable variables such as fecal haemoglobin concentration (f-Hb), age and sex, may simplify CRC diagnosis. We developed, and then externally validated, a multivariable prediction model, the FAST Score, with data from five diagnostic test accuracy studies that evaluated quantitative fecal immunochemical tests in symptomatic patients referred for colonoscopy. The diagnostic accuracy of the Score in derivation and validation cohorts was compared statistically with the area under the curve (AUC) and the Chi-square test. 1,572 and 3,976 patients were examined in these cohorts, respectively. For CRC, the odds ratio (OR) of the variables included in the Score were: age (years): 1.03 (95% confidence intervals (CI): 1.02–1.05), male sex: 1.6 (95% CI: 1.1–2.3) and f-Hb (0–

ObjectiveTo determine whether a faecal immunochemical test (FIT) for faecal haemoglobin concentration (f-Hb) can be safely implemented in primary care as a rule-out test for significant bowel disease (SBD) (colorectal cancer (CRC), higher risk adenoma (HRA) and inflammatory bowel disease (IBD)) when used as an adjunct to the clinical assessment of new bowel symptoms.DesignSingle-centre prospective cohort study of all patients who attended primary care and submitted a FIT in the first calendar year of the service beginning December 2015. f-Hb was estimated using HM-JACKarc (Kyowa Medex) with a clinical cut-off of ≥10 µg Hb/g faeces. Incident cases of CRC were verified via anonymised record linkage to the Scottish Cancer Registry.Results5422 patients submitted 5660 FIT specimens, of which 5372 were analysed (positivity: 21.9%). 2848 patients were referred immediately to secondary care and three with f-Hb ConclusionIn primary care, measurement of f-Hb, in conjunction with clinical assessment, can safely and objectively determine a patient’s risk of SBD.

Background Faecal immunochemical tests for haemoglobin have been recommended to assist in assessment of patients presenting in primary care with lower bowel symptoms. The aim was to assess if, and which, additional variables might enhance this use of faecal immunochemical tests. Methods Faecal immunochemical test analysis has been a NHS Tayside investigation since December 2015. During the first year, 993 patients attending colonoscopy were invited to complete a detailed questionnaire on demographic background, symptoms, smoking status, alcohol use, dietary fibre, red and processed meat intake, physical activity, sitting time, dietary supplement use, family history of colorectal cancer, adenoma, inflammatory bowel disease and diabetes. Significant bowel disease was classified as colorectal cancer, advanced adenoma or inflammatory bowel disease. Results A total of 470 (47.3%) invitees agreed to complete the questionnaire and 408 (41.1%) did. Unadjusted odds ratios for the presence of significant bowel disease compared with undetectable faecal haemoglobin increased with increasing faecal haemoglobin and for faecal haemoglobin 10–49, 50–199, 200–399 and ⩾400 μg Hb/g faeces were 0.95 (95% CI: 0.16–5.63), 2.47 (0.55–1.03), 6.30 (1.08–36.65) and 18.90 (4.22–84.62), respectively. Rectal bleeding and family history of polyps were the only other variables with statistically significant ( P Conclusions Faecal haemoglobin is the most important factor to be considered when deciding which patients presenting in primary care with lower bowel symptoms would benefit most from referral for colonoscopy.

Background In Scotland a new, easier to complete bowel screening test, the Faecal Immunochemical Test (FIT), has been introduced. This test gives more accurate information about an individual’s risk of having colorectal cancer (CRC), based on their age and gender, and could lead to fewer missed cancers compared to the current screening test. However, there is no evidence of the effect on colonoscopy uptake of providing individuals with personalised risk information following a positive FIT test. The objectives of the study are:1)To develop novel methods of presenting personalised risk information in an easy-to-understand format using infographics with involvement of members of the public2)To assess the impact of different presentations of risk information on informed choice and intention to take up an offer of colonoscopy after FIT3)To assess participants’ responses to receiving personal risk information (knowledge, attitudes to screening/risk, emotional responses including anxiety). Methods Adults (age range 50–74) registered on the Scottish Bowel Screening database will be invited by letter to take part. Consenting participants will be randomised to one of three groups to receive hypothetical information about their risk of cancer, based on age, gender and faecal haemoglobin concentration: 1) personalised risk information in numeric form (e.g. 1 in 100) with use of infographics, 2) personalised information described as ‘highest’, ‘moderate’ or ‘lowest’ risk with use of infographics, and 3) as a ‘positive’ test result, as is current practice. Groups will be compared on informed choice, intention to have a colonoscopy, and satisfaction with their decision. Follow-up semi-structured qualitative interviews will be conducted, by telephone, with a small number of consenting participants (n = 10 per group) to explore the acceptability/readability and any potential negative impact of the risk information, participants’ understanding of risk factors, attitudes to the different scenarios, and reasons for reported intentions. Discussion Proving personalised risk information and allowing patient choice could lead to improved detection of CRC and increase patient satisfaction by facilitating informed choice over when/whether to undergo further invasive screening. However, we need to determine whether/how informed choice can be achieved and assess the potential impact on the colonoscopy service. Trial registration The trial is registered on www.isrctn.com on 08/12/2017. Registration no: ISRCTN14254582.

Background Many patients present in primary care with lower bowel symptoms, but significant bowel disease (SBD), comprising colorectal cancer (CRC), advanced adenoma (AA), or inflammatory bowel disease (IBD), is uncommon. Quantitative faecal immunochemical tests for haemoglobin (FIT), which examine faecal haemoglobin concentrations (f-Hb), assist in deciding who would benefit from colonoscopy. Incorporation of additional variables in an individual risk-score might improve this approach. We investigated if the published f-Hb, age and sex test score (FAST score) added value. Methods Data from the first year of routine use of FIT in primary care in one NHS Board in Scotland were examined: f-Hb was estimated using one HM-JACKarc FIT system (Kyowa Medex Co., Ltd., Tokyo, Japan) with a cut-off for positivity ≥10 μg Hb/g faeces. 5660 specimens were received for analysis in the first year. 4072 patients were referred to secondary care: 2881 (70.6%) of these had returned a FIT specimen. Of those referred, 1447 had colonoscopy data as well as the f-Hb result (group A): 2521 patients, also with f-Hb, were not immediately referred (group B). The FAST score was assessed in both groups. Results 1196 (41.7%) of patients who returned a specimen for FIT analysis had f-Hb ≥10 μg Hb/g faeces. In group A, 252 of 296 (85.1%) with SBD had f-Hb > 10 μg Hb/g faeces, as did 528 of 1151 (45.8%) without SBD. Using a FAST score > 2.12, which gives high clinical sensitivity for CRC, only 1143 would have been referred for colonoscopy (21.0% reduction in demand): 286 of 296 (96.6%) with SBD had a positive FAST score, as did 857 of 1151 (74.5%) without SBD. However, one CRC, five AA and four IBD would have been missed. In group B, although 95.2% had f-Hb > 2.12 was found in 13 of 15 (86.7%) with SBD. Conclusions The performance characteristics of the FAST score did not seem to enhance the utility of f-Hb alone. Locally-derived formulae might confer desired benefits.

Background: Quantitative faecal immunochemical tests (FIT) measure faecal haemoglobin concentration (f-Hb), which increases in the presence of colorectal neoplasia and is related to the severity of disease. We examined the diagnostic accuracy of FIT in patients at moderate to high risk of colorectal cancer (CRC) attending for surveillance colonoscopy as per national guidelines. Methods: We undertook a prospective study in two University hospitals, one in Scotland and one in England. Between June 2014 and September 2016, 1103 consecutive patients were invited to complete a FIT before their scheduled colonoscopy: f-Hb was analysed on an OC-Sensor io automated analyser (Eiken Chemical Co., Ltd, Tokyo, Japan)) with a limit of detection (LoD) of 2 µg Hb/g faeces. The diagnostic accuracy of f-Hb for CRC and higher-risk adenoma (HRA) was examined. Findings: 643 patients returned a FIT. Four patients with known IBD were excluded, leaving 639 (57·9%) in the study: age range: 25-90 years (median: 64 years, IQR: 55-71): 54·6% male. Of 593 patients who returned a FIT and completed colonoscopy, 41 (6·9%) had advanced neoplasia (4 CRC, 37 HRA): 238/593 patients (40·1%) had detectable f-Hb of whom 31 (13·0%) had advanced neoplasia (2 CRC, 29 HRA) compared to 10 (2·8%) in those with undetectable f-Hb (2 CRC, 8 HRA).Detectable f-Hb gave negative predictive values of 99·4% for CRC and 97·2% for CRC plus HRA. Interpretation: In patients at moderate to high risk of CRC who are under colonoscopy surveillance, a FIT at the LoD can provide an objective estimate of the risk of advanced neoplasia and could enable tailored scheduling of colonoscopy. Funding Statement: Chief Scientist Office; grant reference number CZH/4/1032. Declaration of Interests: CGF has undertaken consultancy with Kyowa-Medex Co., Ltd, Tokyo, Japan, and has received travel support from Alpha Labs Ltd, Eastleigh, UK. Other authors - none. Ethics Approval Statement: This study had ethical approval from NRES North of Scotland Ethics Committee: reference: 14/NS/0059.

Objectives Quantitative faecal immunochemical tests (FIT) for faecal haemoglobin (f-Hb) in colorectal cancer (CRC) screening pose challenges when colonoscopy is limited. For low positivity rates, high f-Hb concentration cut-offs are required, but little is known about interval cancer (IC) proportions using FIT. We assessed IC proportions using an 80 µg Hb/g cut-off. Methods In two NHS Boards in the Scottish Bowel Screening Programme, f-Hb was estimated for 30,893 participants aged 50–75, of whom 753 participants with f-Hb ≥ 80 µg Hb/g were referred for colonoscopy. ICs, defined as CRC within two years of a negative result, were identified from the Scottish Cancer Registry. Results There were 31 ICs and 30 screen-detected (SD) CRCs, an IC proportion of 50.8% (48.4% for men, 53.3% for women). CRC site distribution was similar between ICs and SD, but ICs were later stage (46.7% and 33.3%, Dukes’ stages C and D, respectively). Of 31 ICs, 23 had f-Hb Conclusions The IC proportion was similar to that seen with guaiac-based FOBT. The later stage distribution of ICs highlights the benefits of lower f-Hb cut-offs, but with 19.4% of ICs having undetectable f-Hb, some cancers would have been missed, even with drastic reduction in the f-Hb cut-off.

Objective To examine associations between faecal haemoglobin concentrations below the cut-off used in colorectal cancer screening and outcomes in the next screening round. Methods In the Scottish Bowel Screening Programme, faecal haemoglobin concentrations and diagnostic outcomes were investigated for participants with a negative result (faecal haemoglobin concentrations Results Of 37,780 participants with negative results, at the next screening round, 556 (1.5%) screened positive and 30,293 (80.2%) negative. Initial median faecal haemoglobin concentrations (2.1 µg Hb/g faeces, IQR: 0.0–13.2) were higher in those with subsequent positive results than those with subsequent negative results (0.0 µg Hb/g faeces, IQR: 0.0–1.4; p Conclusions A higher proportion of participants with faecal haemoglobin concentrations of ≥ 20 µg Hb/g faeces had advanced neoplasia detected at the next round than participants with lower faecal haemoglobin concentrations. Although most relevant when using high faecal haemoglobin concentrations cut-offs, studies of faecal haemoglobin concentrations and outcomes over screening rounds may provide strategies to direct available colonoscopy towards those at highest risk.

Background The National Institute for Health and Care Excellence (NICE) published NG12 in 2015. The referral criteria for suspected colorectal cancer (CRC) caused controversy, because tests for occult blood in faeces were recommended. Faecal immunochemical tests for haemoglobin (FIT), which estimate faecal haemoglobin concentrations (f-Hb), might more than fulfil the intentions. Our aim was to compare the utility of f-Hb as the initial investigation with the NICE NG12 symptom-based guidelines. Methods Data from three studies were included. Patients had sex, age, symptoms, f-Hb and colonoscopy and histology data recorded. Sensitivity, specificity, positive (PPV) and negative predictive value (NPV) of f-Hb and NG12 were calculated for all significant colorectal disease (SCD: CRC, higher risk adenoma and inflammatory bowel disease). Overall diagnostic accuracy was also estimated by the area under the receiver operating characteristic curve (AUC). Results A total of 1514 patients were included. At a cut-off of ≥10 µg Hb/g faeces, the sensitivity of f-Hb for CRC was 93.3% (95% confidence interval (CI): 80.7–98.3) with NPV of 99.7% (95%CI: 99.2–99.9). The sensitivity and NPV for SCD were 63.2% (95%CI: 56.6–69.4) and 96.0% (95%CI: 91.4–94.4), respectively. The NG12 sensitivity and NPV for SCD were 58.4% (95%CI: 51.8–64.8) and 87.6% (95%CI: 85.0–89.8), respectively. The AUC for CRC was 0.85 (95% CI: 0.87–0.90) for f-Hb versus 0.65 (95%CI: 0.58–0.73) for NG12 ( P Conclusion f-Hb provides a good rule-out test for SCD and has significantly higher overall diagnostic accuracy than NG12.

Introduction Post-menopausal women and men with iron deficient anaemia (IDA) require investigation because they harbour a risk of underlying pathology such as cancer (1). We have demonstrated that in patients with colorectal symptoms referred from primary care an undetectable Faecal Haemoglobin (FHb), measured by a Faecal Immunochemical Test (FIT), can be a ‘rule-out test’ for underlying significant bowel disease (2). We wished to examine whether measurement of FHb could assist in the assessment of patients referred from primary care with IDA. Method We prospectively recorded all referrals to the NHS Tayside Colorectal Service from December 2015 – September 2016. GPs were encouraged to request FIT at point of referral in all patients. We used each patients unique Community Health Index number (CHI) to link GP referrals to laboratory results, OGD and colonoscopy findings. The WHO definition of IDA was used (3). FHb concentrations were grouped into undetectable ( 400 µg/g for purposes of analysis. Results 3272 patients were referred. 416 were referred as IDA of which 397 were verified; of these, 214 submitted a FIT test. To date 191 patients have undergone endoscopic procedures. 161 have had both an OGD and colonoscopy. An additional 26 have had OGD only and 3 have had colonoscopy only. At colonoscopy, 26 (15%) had significant bowel disease; 15 had CRC, 9 High-risk adenoma (HRA) and 2 Inflammatory Bowel Disease ( IBD). At OGD, 2 had Upper Gastrointestinal Cancer (UGIC). 116/191 (60%) had undetectable FHb; of these, 5% had significant GI disease (2 had CRC and 4 had HRA). Using a cut-off of ‘undetectable’ FHb ( 75/191 (39%) had detectable FHb; of these 13 (17%) had significant disease; 4 CRC, 5 HRA, 2 IBD, 2 UGIC. 15/164 (7%) had FHb >400; of these 9 (60%) had significant bowel disease (9 CRC). A detectable FHb gave a Positive Predictive Value of 37.1% for CRC rising to 50% for any significant bowel disease. Conclusion Measurement of FHb is of benefit in the assessment of IDA. As concentrations rise, the likelihood of significant underlying GI disease increases from 5% (undetectable) to 39% (detectable) to 60% (very high). Those with high concentrations of FHb should be prioritised for urgent investigations as the likelihood of significant pathology is high. Disclosure of Interest None Declared

Introduction Faecal Immunochemical Tests for haemoglobin (FIT) detect haemoglobin in stool (FHb). FIT has been advocated as a good ‘rule-out’ test for significant bowel disease in the symptomatic population (1). In this pilot study, we examined whether FIT may have a similar role in subjects enrolled in surveillance colonoscopy. Method Between 1stJune 2014 and Sept 30th 2016, 15 consecutive months of surveillance patients were approached at Ninewells Hospital, and 3 consecutive months were approached at St Marks Hospital. Subjects were invited to complete a FIT test prior to their colonoscopy. FHb was measured by Blood Sciences, Ninewells Hospital using an OC-Sensor iO analyser (Eiken Chemical Co., Tokyo, Japan) with an analytic range of 200 µg Hb/g of faeces. Colonoscopy results were recorded and the diagnostic accuracy of the FIT test was examined. Results Of the 1103 patients approached, 643 returned a FIT kit. Four patients had known IBD and were excluded, leaving 639 (58%) in the study; age range 25–90 years (median 64 years, IQR 55–71) 54% were male. Indications for colonoscopy were: adenoma surveillance 312 (48.8%), genetic surveillance 152 (23.8%), other family history 84 (13.1%), cancer follow-up 72 (11.3%), other 19 (3.0%). Of the 639 patients, 46 were excluded from analysis of FIT test performance; 19 patients did not respond to or cancelled colonoscopy appointment, 8 did not attend colonoscopy, 3 patients were not fit to attend, 3 no valid FIT result, 1 cancelled by nurse, 1 had CT colonoscopy, 2 colonoscopy incomplete, 9 colonoscopies not complete by end of study. Of 593 patients who returned a FIT and completed colonoscopy only 7% had significant neoplasia (4 cancers (0.7%), 37 HRA (6.3%)) and 0.8% had IBD. 227/593 patients (38%) had undetectable FIT of whom 2.2% had significant neoplasia (one cancer (0.4%), 4 HRA (1.8%)) and 0.4% had IBD. 366/593 patients (62%) had detectable FIT of whom 9.9% had significant neoplasia (3 cancers (0.8%), 33 HRA (9.0%)) and 1.1% had IBD. Using a FIT cut off level of ‘not detectable’, gave a NPV of 99.6% for CRC and 97.8% for CRC+HRA. 36/41 cases of advanced neoplasia would have been detected. One CRC and 4 HRA would have been missed. Conclusion The yield of significant neoplasia at surveillance colonoscopy was low. A negative FIT was recorded in over one third of subjects and could be used as a ‘rule-out’ test to avoid unnecessary surveillance colonoscopy, at the expense of missing a very small proportion of significant neoplasia. Reference . Mowat C, J Digby, Strachan JA, et al. Faecal haemoglobin and faecal calprotectin as indicators of bowel disease in patients presenting to primary care with bowel symptoms. Gut2016 Sept;65(9):1463–9. Disclosure of Interest None Declared

Introduction Symptoms alone are poor predictors of underlying colonic pathology.1 Yield of significant bowel disease (SBD), [colorectal cancer (CRC), high risk adenoma (HRA, defined as ≥3 or any ≥1 cm) and inflammatory bowel disease (IBD)] is low in patients referred for colonoscopy from primary care at 14%.2 We have shown that undetectable Faecal Haemoglobin (fHb) as measured by a faecal immunochemical test (FIT) is a good rule-out test for SBD.2,3 We introduced FIT tests to primary care in NHS Tayside from 7th December 2015 and report the impact on referral rates and the yield of SBD at colonoscopy from data collected up to 30th September 2016. Method Patients in primary care with new bowel symptoms were encouraged to complete a FIT in addition to blood count and renal function check. FIT tests were analysed in Blood Sciences (HMJACKarc, Kyowa Medex Co. Ltd., Japan) to give fHb within a range of 400 µg Hb/g faeces. Referral rates with FIT were examined along with clinical findings at colonoscopy. Results 4261 FIT kits were analysed (median age 64 years (range: 2–98, IQR: 51–75), 56% female). 3246 (76%) had undetectable fHb, 911 (21%) had detectable fHb and 2.4% were untestable. 1988 patients completed a FIT but were not referred, with 1855 (93.3%) having undetectable fHb. Referrals to the Colorectal Service were 14% lower than in the corresponding time period of the preceding year. 3512 patients were referred; 1925 (55%) had completed a FIT. Of the 924 patients with a FIT result plus colonoscopy, 43% had undetectable FIT, 41% detectable up to 400 µg Hb/g faeces and 16%>400 µg Hb/g faeces. There were 203 cases of SBD (22%); 58 CRC, 87 HRA, 58 new cases of IBD. 33% of those with any fHb had SBD compared with 7% of those with undetectable fHb. Furthermore, of 150 patients who had fHb >400 µg Hb/g faeces, 88 (55%) had SBD. Conclusion Undetectable fHb is offering reassurance that SBD is unlikely and referrals to the Colorectal Service have reduced. At colonoscopy, yield of SBD has increased and is highest in those with detectable fHb. FIT testing is an essential adjunct to the history, examination and blood tests in the assessment of bowel symptoms. References . Jellema P, van der Windt DAWM, Bruinvels DA, et al. Value of symptoms and additional diagnostic tests for colorectal cancer in primary care; systematic review and meta-analysis. BMJ2010;340:c1269. . Mowat C, Digby J, Strachan JA et al. Faecal haemoglobin and faecal calprotectin as indicators of bowel disease in patients presenting to primary care with bowel symptoms. Gut 2016;65(9):1463–9. . McDonald PJ, Digby J, Innes C et al. Low faecal haemoglobin concentration potentially rules out significant colorectal disease. Colorectal Dis 2013;15:e151-9. Disclosure of Interest None Declared

AimsGuaiac faecal occult blood tests are being replaced by faecal immunochemical tests (FIT). We investigated whether faecal haemoglobin concentration (f-Hb) was related to stage in progression of colorectal neoplasia, studying cancer and adenoma characteristics in an evaluation of quantitative FIT as a first-line screening test.MethodsWe invited 66 225 individuals aged 50–74 years to provide one sample of faeces. f-Hb was measured on samples from 38 720 responders. Colonoscopy findings and pathology data were collected on the 943 with f-Hb≥400 ng Hb/ml (80 µg Hb/g faeces).ResultsOf the 814 participants with outcome data (median age: 63 years, range 50–75, 56.4% male), 39 had cancer, 190 high-risk adenoma (HRA, defined as ≥3 or any ≥10 mm) and 119 low-risk adenoma (LRA). 74.4% of those with cancer had f-Hb>1000 ng Hb/ml compared with 58.4% with HRA, and 44.1% with no pathology. Median f-Hb concentration was higher in those with cancer than those with no (p10 mm) compared with small adenoma (pConclusionsf-Hb is related to severity of colorectal neoplastic disease. This has ramifications for the selection of the appropriate cut-off concentration adopted for bowel screening programmes.

We read with interest the work by Haug et al published in Gut .1 Longitudinal data from 4523 participants in the first round of a faecal immunochemical test for haemoglobin (FIT)-based screening programme, of whom 3427 also participated in the second round, were studied. In both first and second rounds, a threshold of 10 µg Hb/g faeces was used. The cohort was followed up for 2 years. The cumulative positivity and the number of participants diagnosed with neoplasia over the two rounds of screening were determined and compared with a hypothetical strategy involving single round screening with use of lower faecal haemoglobin concentration (f-Hb) thresholds and omission of the second round. It was suggested that lowering the f-Hb threshold and extending the screening interval could possibly enhance population-based screening programmes. In our pilot evaluation of FIT-based screening in Scotland, a much higher f-Hb threshold (≥80 µg Hb/g faeces) was employed.2 …

1University of Dundee, Nethergate, Dundee, DD1 4HN, Scotland, UK *Author for correspondence: r.j.c.steele@dundee.ac.uk The most commonly used strategy in colo­ rectal cancer (CRC) screening pro grams involves the use of stool tests to detect occult blood, and guaiac fecal occult blood tests (gFOBTs) are, to date, the only fecal tests shown to reduce CRC mortality in population­based randomized trials [1]. However, gFOBTs also carry disadvantages. A major concern is that interval cancers account for around 50% of cancers detected in gFOBT screened populations [2] and recent data show that gFOBTs are less sensitive in women than in men, and in both rectal and right­sided cancers when compared with left­sided disease [2,3]. In addition, the test is associated with a high false­positive rate with no neoplasia detected in around half of colonoscopies performed following a positive gFOBT [2,3]. This may be, in part, explained by the fact that gFOBTs are not specific for human hemoglobin (Hb) and are subject to possible dietary interference from, for example, red meat and high­peroxidase fruits and vegetables. As a result, it has been common practice to instruct participants to adhere to dietary restrictions ahead of sample collection, although this may act as a barrier to screening and affect participation rates [4]. However, data from a meta­analysis did not support dietary restrictions with gFOBTs, leading to recommendations that restrictions are abandoned to improve adherence rates [5]. Fecal immunochemical tests (FITs) are now available and are increasingly being used in screening programs. Unlike gFOBTs, FITs are specific for the detection of human Hb, eliminating any potential for dietary interference, and are also more specific than gFOBT for lower gastrointestinal bleeding. In addition, modern FITs generally allow a more convenient method of sample collection, and are associated with better participation rates [6]. Another major advantage of FIT is that automated versions not only eliminate interobserver variability, but also the quantitative nature of these tests allow provision of a measured fecal Hb concentration. Screening program “...the adoption of fecal immunochemical tests in colorectal cancer screening programs has potential to address participation, appropriate positivity rates and the problem of false‐negative results.” EDITORIAL

ObjectiveTo investigate the relationship between deprivation and faecal haemoglobin concentration (f-Hb).SettingScottish Bowel Screening Programme.MethodsA total of 66725 men and women, aged 50 to 74, were invited to provide a single sample for a faecal immunochemical test. Deprivation was estimated using the Scottish Index of Multiple Deprivation quintiles: f-Hb was measured (OC-Sensor, Eiken, Japan) on 38439 participants. The relationship between deprivation quintiles and f-Hb was examined.ResultsMedian age was 60 years, 53.6% women, with 14.1%, 19.7%, 17.7%, 25.9% and 22.6% in the lowest to the highest deprivation quintiles respectively. No detectable f-Hb was found in 51.9%, ranging from 45.5% in the most deprived up to 56.5% in the least deprived. As deprivation increased, f-Hb increased (p ConclusionsDeprivation and f-Hb are related. This has important implications for selection of cut-off f-Hb for screening programmes, and supports the inclusion of deprivation in risk-scoring systems.

Objectives To investigate the characteristics of participants screened for bowel cancer using a faecal immunochemical test for haemoglobin (FIT). Setting Scottish Bowel Screening Programme. Methods 65909 men and women in two NHS Boards, aged 50 to 74, were invited to participate in an evaluation of FIT as a first-line test. Uptake was calculated by sex, age in quintiles, and deprivation in quintiles, and compared with a group who had completed a guaiac faecal occult blood test (gFOBT) and for whom details of sex, age and deprivation were well documented. Results FIT kits from 38672 participants were tested. The overall uptake of 58.7% was significantly higher than the 53.9% for gFOBT (p < 0.0001). Uptakes in the two NHS Boards were 57.6% and 54.4% for men and 63.2% and 59.1% for women, higher than the 49.5% and 58.1% completing gFOBT. Uptake was higher for FIT than gFOBT in all age and deprivation quintiles for both men and women in both NHS Boards. The difference in uptake fell with age for men but rose for women; the increase in uptake was greater for men than women. Uptake fell as deprivation decreased for both sexes, and was similar in both NHS Boards. Conclusions Use of FIT increases uptake over gFOBT, and the greatest increases are seen in men, younger participants, and more deprived individuals, groups for which an increase in uptake is likely to be beneficial. The results support a move to FIT as a first-line screening test for those countries still using gFOBT.

Objectives To evaluate a two-tier reflex guaiac-based faecal occult blood test (gFOBT)/faecal immunochemical test (FIT) algorithm in screening for colorectal cancer. Setting Fourth screening round in NHS Tayside (Scotland). Methods gFOBT were sent to 50–74-year-olds. Participants with five or six windows positive were offered colonoscopy. Participants with one to four windows positive were sent a FIT and, if positive, were offered colonoscopy. Participants providing an untestable gFOBT were sent a FIT and, if positive, were offered colonoscopy. Outcomes following positive results, cancer stages and key performance indicators were assessed. Results Of 131,885 invited, 73,315 (55.6%) responded. There were 66,957 (91.3%) negative, 241 (0.3%) strong positive, 5230 (7.1%) weak positive and 887 (1.2%) untestable results. The 241 participants who had five or six windows positive had more cancers than those positive by other routes: only 3 of the 30 cancers (9.7%) were Dukes' A. Among the 983 positive results from the weak positive gFOBT then positive FIT route, there were fewer cancers and more normal colonoscopies, but more adenomas than in the group with a strong positive gFOBT. In those with an untestable gFOBT, 77 had a positive FIT result, with fewer true and more false positive results than in the other groups. Fewer males had cancer and stages were earlier than in females, but more had adenoma. The detection rate for cancer was 0.18% and the PPV for cancer and all adenomas was 41.3%. Conclusions The algorithm and FIT following a weak positive gFOBT have advantages. FIT following an untestable gFOBT warrants review.

Faecal immunochemical tests (FIT) are becoming widely used in colorectal cancer screening. Estimation of faecal haemoglobin concentration in a large group prompted an observational study on gender and age.A single estimate of faecal haemoglobin concentration was made using quantitative automated immunoturbidimetry. Potential reference intervals were calculated for men and women and for age quintiles according to the Clinical and Laboratory Standards Institute Approved Guideline. The percentages of positive results were calculated at a number of concentrations. The percentages of individuals who fell into different risk groups were assessed.The 97.5 percentiles, potential upper reference limits, were 519 ng haemoglobin/mL (90% CI: 468–575) for men and 283 ng haemoglobin/mL (90% CI: 257–316) for women. Concentrations increased with age in both genders. Decision limits have advantages over reference intervals. At any cut-off concentration, more men are declared positive than women and more older people are declared positive than younger people. Future risk of neoplasia is higher in men than in women and in older people.Faecal haemoglobin concentrations vary with gender and age. More tailored strategies are needed in screening programmes. Faecal haemoglobin concentration could be included in individual risk assessment scores. These data should assist in screening programme design.