UK Bowel Cancer Screening Programme Research Articles

P371 Calprotectin Testing: A Methods Comparison Study

Abstract Background In conventional laboratory-based Enzyme Linked Immunosorbant Assays (ELISA) for calprotectin measurement, raw stool is returned to and manually processed by testing laboratories. The OCS-Pledia calprotectin test uses the same stool collection device as the OCS-Pledia FIT test used in the UK Bowel cancer screening programme. In brief, individuals sample their stool with a picker and transfer to a preprepared buffered diluent, which is then returned to the laboratory for fully automated analysis. We have previously shown that a stool concentration of >100ug/g measured using the IDK calprotectin ELISA was the optimal cut-off to distinguish IBS from IBD (sensitivity 86%, specificity 90%, positive predictive value 39%, negative predictive value 99%). We undertook a methods comparison study to report the stability, linearity and potential bias of the OCS-Pledia calprotectin assay compared with IDK ELISA. Methods 32 stool samples were collected from people with GI pathology, and homogenised. Samples were prepared for calprotectin testing using IDK and OCS-Pledia less than 4 hours from excretion (mean2.6 [SD]1.3 hrs). Samples were left at room temperature and further extracts taken at 6, 24, 48, 72, and 168 hours. Pairwise analysis of samples across the reporting range was undertaken and linearity and bias assayed by Pearson’s correlation and Bland-Altmann analysis, respectively. Results Calprotectin was stable over one week in both the OCS-Pledia buffered and the IDK ELISA unbuffered stool samples. However, OCS-Pledia results showed lower variance than that of the IDK ELISA, especially at later time points. There was a linear relationship between calprotectin measured with the OCS-Pledia and IDK-ELISA assays (R2=0.85; p<0.0001). The OCS-Pledia calprotectin assay has a positive bias across the reporting range. This led to 40 samples reading elevated calprotectin levels on OCS-Pledia but within normal range on IDK-ELISA. All 40 had colonic inflammation and therefore were false negative IDK-ELISA. Calprotectin concentrations of 600ug/g and 400ug/g measured using the OCS-Pledia assay were equivalent to concentrations of about 250ug/g and 100ug/g measured using the IDK ELISA. Conclusion OCS- Pledia assays for the measurement of calprotectin are likely to superseded conventional ELISAs because they are cheaper, easier to automate and do not involve laboratory staff pre-processing stool samples. Like conventional ELISA assays calprotectin is stable for at least one week. Clinicians will need to be aware, however, of the positive bias across the reporting range of calprotectin and adjust their positivity thresholds.

Optimizing the Design of a Repeated Fecal Immunochemical Test Bowel Cancer Screening Programme With a Limited Endoscopy Capacity From a Health Economic Perspective

ObjectivesIn 2016, it was announced that the fecal immunochemical test (FIT) would replace the guaiac fecal occult blood test in the UK Bowel Cancer Screening Programme. England has limited endoscopy capacity. This study informed decision making by determining the most cost-effective FIT screening strategy (age range, frequency, and FIT threshold) under a constrained endoscopy capacity. MethodsAn economic model with a colorectal cancer natural history component was used to model 60 221 screening strategies with first screening at age 50 to 60 years, screening interval of 1 to 6 years, 3+ screening episodes, and FIT integer threshold of 20 to 180 μg hemoglobin/g feces. Screening strategies requiring the same endoscopy capacity were compared to determine the characteristics of the most cost-effective strategies. ResultsWith 50 000 annual screening referral colonoscopies, the 20 most cost-effective strategies had a starting age of 50 to 53 years, 2-yearly screening, 7 or 8 rounds of screening, and FIT threshold of 127 to 166. Compared with a 2-yearly screening interval, screening less frequently (3-, 4-, 5-, or 6-yearly) with a more sensitive FIT was less cost-effective. ConclusionsThe UK Bowel Cancer Screening Programme should use a 2-yearly FIT screening interval. When endoscopy capacity increases, the screening starting age should be reduced first followed by reducing the FIT threshold. These findings are relevant for other colorectal cancer screening programs with constrained endoscopy capacity.

Physical activity advice in the UK bowel cancer screening setting: qualitative healthcare professional perspectives.

Providing physical activity advice in the bowel cancer screening setting could help to reduce the risk of cancer and cardiometabolic disease in older adults. This study investigated the views of healthcare professionals (HCPs) regarding the provision of physical activity advice as part of the UK Bowel Cancer Screening Programme. A purposive sample of HCPs (aged 22-63 years, with 1-26 years of experience) from four bowel cancer screening disciplines (four endoscopists, four colorectal surgeons, four staff nurses and four specialist screening practitioners) were recruited from a large National Health Service gastroenterology unit. Data collection used individual interviews and focus groups, with topics being guided by an a priori topic guide. All interviews and focus groups were audio-recorded and transcribed verbatim. Three key themes, which contextualize the views and perceptions of HCPs recruited to the study, emerged from the framework analysis: (i) appraisal of the concept; (ii) perceived barriers to implementation; (iii) steps to implementation. While the general concept was viewed positively, there were differences of opinion and a range of perceived barriers were revealed. Ideas for effective implementation were also presented, taking into consideration the need for time efficiencies and importance of optimizing effectiveness. This qualitative study provided important insights into the perceptions of HCPs regarding the provision of physical activity advice in the bowel cancer screening setting, and yielded novel ideas for effective implementation.

Enterobius vermicularis infection associated with positive faecal occult blood testing and eosinophilia

A 60-year-old asymptomatic man attended following positive faecal occult blood testing in the UK bowel cancer screening programme. He was a regular carer for young grandchildren. Recent blood tests showed an elevated eosinophil count (0·82 × 109 cells per L [range 0·04–0·4]). Colonoscopy showed patchy erythema and erosions with multiple Enterobius vermicularis (threadworm or pinworm) in the caecum (figure, A). Histopathological examination (figure, B) showed surface epithelial erosion, with attenuation, patchy regenerative changes and an E vermicularis parasite (figure, C). Crypt architecture was maintained, but there was an eosinophil-rich inflammatory cell infiltrate within the lamina propria (figure, D).

Volatile organic compounds emitted from faeces as a biomarker for colorectal cancer.

SummaryBackgroundColorectal cancer remains a leading cause of mortality and morbidity. The UK Bowel Cancer Screening Programme (BCSP) has demonstrated that detection of colorectal cancer at an earlier stage and identification of advanced pre‐malignant adenomas reduces mortality and morbidity.AimTo assess the utility of volatile organic compounds as a biomarker for colorectal neoplasia.MethodsFaeces were collected from symptomatic patients and people participating in the UK BCSP, prior to colonoscopy. Headspace extraction followed by gas chromatography mass spectrometry was performed on faeces to identify volatile organic compounds. Logistic regression modelling and 10‐fold cross‐validation were used to test potential biomarkers.ResultsOne hundred and thirty‐seven participants were included (mean age 64 years [range 22‐85], 54% were male): 60 had no neoplasia, 56 had adenomatous polyp(s) and 21 had adenocarcinoma. Propan‐2‐ol was significantly more abundant in the cancer samples (P < 0.0001, q = 0.004) with an area under ROC (AUROC) curve of 0.76. When combined with 3‐methylbutanoic acid the AUROC curve was 0.82, sensitivity 87.9% (95% CI 0.87‐0.99) and specificity 84.6% (95% CI 0.65‐1.0). Logistic regression analysis using the presence/absence of specific volatile organic compounds, identified a three volatile organic compound panel (propan‐2‐ol, hexan‐2‐one and ethyl 3‐methyl‐ butanoate) to have an AUROC of 0.73, with a person six times more likely to have cancer if all three volatile organic compounds were present (P < 0.0001).ConclusionsVolatile organic compound analysis may have a superior diagnostic ability for the identification of colorectal adenocarcinoma, when compared to other faecal biomarkers, including those currently employed in UK. Clinical trial details: National Research Ethics Service Committee South West ‐ Central Bristol (REC reference 14/SW/1162) with R&D approval from University of Liverpool and Broadgreen University Hospital Trust (UoL 001098).

Multicentre randomised controlled trial comparing standard and high resolution optical technologies in colorectal cancer screening

Background and objectivesThe UK bowel cancer screening programme (BCSP) has been established for the early detection of colorectal cancer offering colonoscopy to patients screened positive by faecal occult blood tests....

Incidence and characteristics of Ileo-colonic neuroendocrine tumours identified in the UK bowel cancer screening programme

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Measurement of polyp size at colonoscopy: a proof-of-concept simulation study to address technology bias

We introduce a novel, proof-of-concept polyp measurement device for the design of future colonoscopes. In a simulation study, 50 expert endoscopists used three measurement strategies (method 1: no visual cues;...

PTH-067 Incidental Diagnosis of Inflammatory Bowel Disease in A British Bowel Cancer Screening Cohort: 6-Year Clinical Outcome of The First Reported Cohort

<h3>Introduction</h3> The UK Bowel Cancer Screening programme (BCSP) was launched in 2006 in England and Wales, screening individuals aged 60–69 years with a Faecal Occult Blood test (FOBt) followed by a screening colonoscopy if FOBt positive. We reported the first ever experience of incidental diagnosis of Inflammatory bowel disease (IBD) through screening in 2012. We present a 6 year follow-up of this cohort. <h3>Methods</h3> We conducted a retrospective case record review of clinical outcomes until 31^st December 2015 for patients diagnosed with IBD from the BCSP from April 2008 until September 2011. We reviewed their symptoms at diagnosis, treatment course and compared stage of disease at initial presentation to that at last follow-up. <h3>Results</h3> Between April 2008 and September 2011, 136,811 patients were invited to the BCSP and 67,485 were screened with a 49.33% uptake and FOBt positivity of 2.02%. Colonoscopy was performed in 1401 patients and 13 patients (3 female) were diagnosed with IBD. Of these, 6 patients had Ulcerative colitis (UC), 5 had Crohn’s disease (CD), 2 had IBD-unclassified (IBDU). One IBDU patient was subsequently re-classified as UC during follow-up. At diagnosis 7 (53.8%) patients were asymptomatic. An asymptomatic patient died of an unrelated cause, with follow-up data available for 12 patients. Median follow-up time was 80 months (range 39–87 months). Using the Montreal classification the distribution for UC included E1 (2), E2 (2) and E3 (2) and in CD showed L2 (7). Four CD patients had B1 disease and 1 had B2. Disease progressed in 2 patients and all 6 (100%) asymptomatic patients developed symptoms during follow-up. Treatment included steroids (10), 5 ASA (12), Azathioprine (6); Methotrexate (1) and Anti-TNF (Infliximab (2); Adalimumab (1)). Median time to immunomodulator was 29.5 months and to anti-TNF, 28.0 months. Mean CRP at diagnosis for those who progressed to Immunomodulator was 10.4 compared to 5.5 in those that didn’t and 15.5 in those that required biologics. A patient with symptomatic IBDU underwent subtotal colectomy 54 months after diagnosis but died 7 days post-operatively. Another patient died at 39 months from an unrelated cause. <h3>Conclusion</h3> Incidental diagnosis of IBD presents an important model for the study of early disease. A proportion of initially asymptomatic patients demonstrate disease progression with a rapid requirement for treatment escalation. <h3>Disclosure of Interest</h3> None Declared

OC-048 The Use of Volatile Organic Compounds Emitted from Stool as a Biomarker for Colonic Neoplasia

Introduction Colorectal cancer (CRC) remains a leading cause of mortality worldwide. The incidence has increased by 6% in the last decade and it is the third most common malignancy in the UK, accounting for approximately 15,000 deaths annually. The UK Bowel Cancer Screening Programme has demonstrated that detection of CRC at an earlier stage and identification of advanced pre-malignant adenomas can reduce cancer-associated mortality. We analysed the volatile organic compounds (VOCs) emitted from stool to assess their utility as a biomarker for colonic neoplasia. Methods Stool was collected from symptomatic patients referred for colonoscopy and those within the BCSP. SPME headspace extraction followed by GC-MS was performed, in order to identify VOCs. The outcome of colonoscopy was classified as no-neoplasia, adenomatous polyp(s) and cancer. Data analysis was performed in R, Stata and Metaboanalyst, utilising Student’s t test, Fisher’s exact test, ANOVA, false discovery rate correction, PLS-DA, factor analysis and ROC analysis. Logistic regression modelling with 10 fold cross validation was used to test potential biomarkers. Results 137 patients were included, with a mean age of 64 yrs (range 22–85), 54% were males. 60 patients had no neoplasia, 56 adenomatous polyp/s and 21 had CRC. 162 VOCs were identified across all samples, mean number in no-neoplasia 58.1 and 55.2 in neoplastic group, p = 0.51. VOC analysis was able to differentiate those with higher risk neoplastic disease with the greatest confidence. When comparing those with cancer to no neoplasia PLS-DA demonstrated separation, compound A was significantly more abundant in the CRC samples (p = *VOCs referred to as Compound A, B, X and Y due to potential future IP. Conclusion VOC analysis has a superior diagnostic ability for the identification of colorectal adenocarcinoma, when compared to other faecal based biomarker, including those currently employed in UK population based screening. Disclosure of Interest None Declared

OC-046 The ACPGBI/BSG Complex Colorectal Polyp Minimum Dataset: An Update

Introduction Variation in the assessment of large non-pedunculated colorectal polyps (LNPCPs) appears to lead to variable and suboptimal management outcomes. 1 Multidisciplinary discussion has been advocated to optimise management. Our ACPGBI/BSG evidence-based, expert consensus minimum dataset developed in 2014–15 has been felt to enhance LNPCP assessment and decision making. 2 We propose that further refinement will ensure increased robustness. Methods A 14 person ACPGBI/BSG approved multidisciplinary panel reassessed the original minimum dataset using Delphi consensus methodology. A subcommittee tested the proforma dataset’s applicability and usability for multidisciplinary discussion over 20 LNPCP cases. This process was intended to find any previously unidentified patient and polyp factors that may influence management. Proposed additional parameters were then subject to voting with >80% agreement required for consensus. The updated dataset was then assessed with a further 20 LNPCP cases. Results 8 new parameters considered helpful for LNPCP assessment were identified. Whilst patient parameters such as symptoms, treatment preferences and comorbidity had previously been identified, it was agreed that establishing patient amenability to undergo treatment at another hospital was important and may potentially increase available therapeutic options. With regards to lesion characteristics, it was felt that specification of the ‘SMSA scoring system’ encouraged more comprehensive and standardised lesion assessment of the complexity of lesion endoscopic resectability. 2 Comprehensive photodocumentation was also considered necessary with parameters agreed relating to the capture of morphology and surface features and specific rectal imaging. Further piloting of the revised dataset identified no further required parameters (see figure). Conclusion The development of an ACPGBI/BSG minimum dataset allows for comprehensive and standardised multidisciplinary LNPCP assessment. It forms part of a structured ACPGBI/BSG management framework for LNPCPs, also comprising guidelines and key performance indicators. In addition to facilitating multidisciplinary discussion, the dataset can also serve as an aide memoire to guide detailed endoscopic assessment. The updated consensus process ensures that all factors pertinent to decision making are included whilst applicability and usability are confirmed following further piloting. References 1 Chattree A, Painter J, Silcock J, et al . Marked Variation in Endoscopic Mucosal Resection Outcomes within the UK Bowel Cancer Screening Programme. United European Gastroenterology Journal 2015; 2 (Supp 1) 2 Rutter MD, Chattree A, Barbour J, et al . BSG/ACPGBI Guidelines for the management of large non pedunculated colorectal polyps. Gut 2015; 0 :1–27 Disclosure of Interest None Declared

PTH-091 Incidental Diagnosis of Inflammatory Bowel Disease Through The Bowel Cancer Screening Programme: A 7 Year Experience

Introduction The UK Bowel Cancer Screening Programme (BCSP) launched in 2006, currently screens individuals aged 60–74 years through a Faecal Occult Blood test (FOBt). If positive patients are invited for colonoscopy. We reported in 2012 the first ever experience of incidental diagnosis of IBD through a screening cohort and now present a 7 year experience. Methods We conducted a retrospective assessment of BCSP outcomes at our centre between April 2008 (launch) and December 2015. Assessment included the number of patients invited for screening, number successfully screened (inclusive of “normal” and “abnormal” FOBt) and the number of index colonoscopies. In those with confirmed IBD diagnosis, clinical outcomes, symptoms at diagnosis, disease distribution and behaviour and treatments undertaken were recorded through patient record and case note reviews. Results Of 358,716 invited individuals 180,075 were adequately screened (uptake 50.2%) with FOBt positivity of 1.83%. Of 3598 index colonoscopies undertaken, an incidental diagnosis of IBD was made in 37 (12 female) patients. Ulcerative Colitis (UC) was diagnosed in in 22 (59.4%) patients and Crohn’s (CD) in 10 (27.0%). A further 5 (13.5%) patients were diagnosed with IBD-type unclassified (IBDU) of which 2 were reclassified as UC through follow up. In those diagnosed with UC initially 9 (41.0%) had proctitis, 8 (36.4%) left sided disease and 5 (22.7%) had extensive disease. The majority of CD patients (80%) had an isolated colonic distribution and behaviour was non-stricturing and non-penetrating (70%) or stricturing (30%). Follow up data was available for 25 (67.6%) patients over a median of 40.5 months (range 3–87) of which 14 patients were asymptomatic at diagnosis. Eleven (78.6%) became symptomatic and 2 (8.3%) demonstrated phenotypic progression during follow up. Treatment included 5 ASA (23), steroids (14), Immunomodulation (Azathioprine – 7: Methotrexate – 1) and Anti-TNF (Infliximab -2; Adalimumab – 1). Median time to immunomodulation was 29.0 months and to anti-TNF treatment was 28.0 months. Five patients died: 3 from unrelated causes, 1 from an unknown cause and 1 seven days after subtotal colectomy (undertaken 54 months after diagnosis with symptomatic IBDU). Conclusion An incidental diagnosis of IBD at screening is not uncommon, with an incidence of 1.0% in our cohort . A proportion of patients demonstrate significant disease progression requiring immunomodulation, biologic therapy or surgery. IBD detection from screening provides a unique model to study early disease in ‘elderly’ (and potentially asymptomatic) patients. Disclosure of Interest None Declared

PTU-018 The Emperor’s New Clothes: An Alternative Perspective on Colonoscopy

Introduction Following the quality improvement programme introduced to pave the way for the UK Bowel Cancer Screening Programme (BCSP), there was an improvement in caecal intubation rate from 76.9% in 1999 to 92.3% in 2011.1 90.2% suffered mild discomfort or less, although this was assessed and reported by the endoscopist. 53.6% of symptomatic patients had abnormal examinations but it was not clear how many of the pathologies identified were incidental findings. We aimed to determine the percentage of patients whose colonoscopy findings explained their symptoms (the diagnostic yield) and to compare endoscopist and patient assessment of colonoscopy tolerance. Methods Endoscopists and patients undergoing colonoscopy independently provided a Gloucester comfort score (GCS 1: comfortable; 5: severe discomfort). Endoscopic and subsequent histological findings were recorded. Results Symptomatic patients (n = 107; 46.7% male, mean age 55.0±1.6 yrs) were younger than BCSP patients (n = 46; 65.2% male, mean age 67.0±0.9; P Conclusion Almost half of patients having diagnostic colonoscopy reported moderate to severe discomfort, which was markedly underestimated by endoscopists. If the true diagnostic yield is only 17%, it would seem appropriate to offer patients a less invasive, better tolerated alternative as a first line test. Procedural tolerance was much better in the BCSP, where endoscopists were more accurate in grading patient discomfort, which may partly be explained by the male predominance. However, GCS 4–5 scores were still three times as common as reported in the national audit. Reference 1 Gavin DR, et al. Gut 2013;62:242–249. Disclosure of Interest None Declared

OC-077 Does Faecal Occult Blood Testing Help Identify Ileo-Colonic Neuroendocrine Tumours in the UK Bowel Cancer Screening Programme (BCSP)?

Introduction There has been an increase in the incidence of ileo-colonic NETs in recent years, partly from endoscopy. There is no published data on the incidence of NETs diagnosed in the UK ‘double’ screen BCSP of initial Faecal Occult Blood stool test (FOBt) and, if abnormal, colonoscopy. The incidence (per 100 k) of colorectal cancer (CRC) in FOBt abnormal UK BCSP colonoscopy is 55 times that of the population incidence (10 k vs 184). 1 The aim of this study was to identify NETs diagnosed and recorded at UK BCSP colonoscopy between 2005–14. Methods Data requests were made to UK BCSP for details of screened populations, abnormal FOBts, and colonoscopies performed and CRCs diagnosed. NET related queries were run across 3 database tables; ‘Polyp Histology Polyp Architecture’, ‘Lesion Type’, ‘Histology Snomed’. Incidence (per 100 k) was compared with those from the SEER database; 2 small intestine and colorectal NETs 2.4; rectal 0.9, other colonic 0.4, appendiceal 0.2, small intestine 0.9. Results 13 million people completed FOBt screening with 260 k abnormal FOBt and 217 k colonoscopies. 146 NETs were identified with an incidence of 67 (per 100 k colonoscopies). The incidence of NETs (per 100 k colonoscopies) by site was 29 rectal, 18 other colonic, 1 appendiceal, and 11 small intestine. Ratios of BCSP to SEER incidences was 29 overall NET, 32 rectal, 45 other colonic, 5 appendiceal, and 12 small intestine. Conclusion The incidence of NETs at UK BCSP colonoscopy following an abnormal FOBt is markedly higher than the SEER population incidence. The effect is greatest for rectal and other colonic NETs although less than that seen with CRC (55 x) following FOBt screening. There is no published data on the incidence of small intestine NETs identified from terminal ileum intubation during ‘single’ or ‘double screen’ BCSP. However, the rectal NET incidence in the UK FOBt BCSP is lower (29 per 100 k colonoscopies) than that published from ‘single screen’ colonoscopy-only BCSP (50–70 per 100 k colonoscopies). 3 This suggests endoscopic screening itself is more helpful than FOBt screening in identifying rectal NETs. References 1 Logan RF, Patnick J, Nickerson C, et al . Outcomes of the Bowel Cancer Screening Programme (BCSP) in England after the first 1 million tests. Gut 2012; 61 (10):1439–1446. 2 Modlin IM, Lye KD, Kidd M. A 5-decade analysis of 13,715 carcinoid tumours. Cancer 2003; 97 (4):934–959. 3 Kaminski M, Polkowski M, Regula J. Prevalence and endoscopic features of rectal neuroendocrine tumours (carcinoids) among 50148 participants of the Polish colorectal-cancer screening programe. Gut 2007; 56 (Suppl III): A310. Disclosure of Interest None Declared

Sa1896 Incidental Diagnosis of Inflammatory Bowel Disease in a British Bowel Cancer Screening Cohort: 6-Year Clinical Outcome Follow-Up of the First Reported Cohort

Introduction The UK Bowel Cancer Screening programme (BCSP) was launched in 2006 in England and Wales, screening individuals aged 60–69 years with a Faecal Occult Blood test (FOBt) followed by a screening colonoscopy if FOBt positive. We reported the first ever experience of incidental diagnosis of Inflammatory bowel disease (IBD) through screening in 2012. We present a 6 year follow-up of this cohort. Methods We conducted a retrospective case record review of clinical outcomes until 31 st December 2015 for patients diagnosed with IBD from the BCSP from April 2008 until September 2011. We reviewed their symptoms at diagnosis, treatment course and compared stage of disease at initial presentation to that at last follow-up. Results Between April 2008 and September 2011, 136,811 patients were invited to the BCSP and 67,485 were screened with a 49.33% uptake and FOBt positivity of 2.02%. Colonoscopy was performed in 1401 patients and 13 patients (3 female) were diagnosed with IBD. Of these, 6 patients had Ulcerative colitis (UC), 5 had Crohn’s disease (CD), 2 had IBD-unclassified (IBDU). One IBDU patient was subsequently re-classified as UC during follow-up. At diagnosis 7 (53.8%) patients were asymptomatic. An asymptomatic patient died of an unrelated cause, with follow-up data available for 12 patients. Median follow-up time was 80 months (range 39–87 months). Using the Montreal classification the distribution for UC included E1 (2), E2 (2) and E3 (2) and in CD showed L2 (7). Four CD patients had B1 disease and 1 had B2. Disease progressed in 2 patients and all 6 (100%) asymptomatic patients developed symptoms during follow-up. Treatment included steroids (10), 5 ASA (12), Azathioprine (6); Methotrexate (1) and Anti-TNF (Infliximab (2); Adalimumab (1)). Median time to immunomodulator was 29.5 months and to anti-TNF, 28.0 months. Mean CRP at diagnosis for those who progressed to Immunomodulator was 10.4 compared to 5.5 in those that didn’t and 15.5 in those that required biologics. A patient with symptomatic IBDU underwent subtotal colectomy 54 months after diagnosis but died 7 days post-operatively. Another patient died at 39 months from an unrelated cause. Conclusion Incidental diagnosis of IBD presents an important model for the study of early disease. A proportion of initially asymptomatic patients demonstrate disease progression with a rapid requirement for treatment escalation. Disclosure of Interest None Declared

Tu2087 The First Randomised Controlled Trial of Endocuff Vision® Assisted Colonoscopy Versus Standard Colonoscopy for Polyp Detection in Bowel Cancer Screening Patients (E-CAP study)

Introduction Up to 25% polyps are missed during colonoscopy. The Endocuff Vision® is a cap with soft flexible arms that attaches to the colonoscope tip and improves views during withdrawal. We have performed the first randomised controlled trial to identify the role of Endocuff Vision® in improving polyp detection. We aim to investigate the impact of Endocuff Vision® assisted colonoscopy on polyp detection, as compared to standard colonoscopy, in the UK Bowel Cancer Screening Programme (BCSP). Methods Single centre, parallel group, randomised controlled trial. Ethics ref: 14/SC/0207. Adopted on UKCRN portfolio (ID: 16985). Patients attending for BCSP colonoscopy were stratified based on attendance for index screening colonoscopy or for polyp surveillance. Within each stratum participants were randomised to either Standard or Endocuff assisted colonoscopy. All procedures were performed by accredited BSCP endoscopists, who have carried out > 5000 colonoscopies and have caecal intubation rates of >90%. Results 534 patients recruited from Sep 2014 to Sep 2015. 3 excluded due to new diagnosis of polyposis syndrome. 531 were included and randomised to the 2 study arms. No significant difference was seen between the 2 groups for the primary endpoint of number of polyps per patient. Secondary endpoints: No significant difference was observed between the 2 groups for adenoma detection rate (ADR) or number of adenomas per patient (Table 1). No significant adverse events were encountered during the study in either arm. The cecal intubation time was not prolonged and patients did not experience any additional discomfort due to the Endocuff Vision. Conclusion In the UK, bowel cancer screening is performed by highly experienced endoscopists. Our results suggest that in expert hands, ADR exceeds 60% even without Endocuff. In such settings, Endocuff Vision did not improve polyp detection rates (PDR) or ADR. However, it did not cause any adverse events, prolong procedure duration or cause additional discomfort. These data demonstrate the safety and feasibility of Endocuff. However, no additional gain was demonstrated in expert hands. Disclosure of Interest None Declared

Ethnic variation in colorectal cancer risk following a positive faecal occult blood test in an English bowel cancer screening programme centre.

The literature on colorectal cancer (CRC) screening and ethnic diversity is dominated by studies from the USA. There are no such published data from the UK bowel cancer screening programme (BCSP) population. The Wolverhampton Bowel Cancer Screening Centre serves a population of 900,000 in the Black Country and South Staffordshire. South Asians (SA) comprise 9% of the population. We aimed to determine the effects of ethnicity and sex on the risk for cancer or adenoma detected by colonoscopy following a positive faecal occult blood test over a 5-year period (2007-2011). Data were collected from the prospectively maintained BCSP cohort. South Asian patients were identified and compared with those of non-South Asian ethnicity, and colonoscopy outcomes were determined. A total of 3552 participants underwent BCSP colonoscopy (non-South Asian=3363; SA=189). There were 271 cancers (7.6%) detected within the non-South Asian group and seven cancers (0.2%) in the South Asian population (P<0.05). The probability of colon cancer is higher [odds ratio (OR)=3.84, P<0.05] in non-South Asians compared with South Asians. Patients in the 65-70-year age group have the highest risk (OR=1.60; P<0.05) for CRC. During the study 1313 adenomas were detected. A total of 771 high-risk and intermediate-risk adenomas were detected in the non-South Asian group, and 14 were detected in the South Asian group. The risk of adenoma in non-South Asians is six times higher than in South Asians (OR=5.99, P<0.001) following positive faecal occult blood testing. There are fewer colorectal cancers in South Asians compared with the non-South Asian population in this regional study. This is the first such study in the BCSP population.

PWE-059 Incidence of endoscopically and histologically confirmed ileal ulceration in a sequential cohort of patients undergoing screening colonoscopy as part of the uk bowel cancer screening programme

Introduction The incidence of ileal ulceration in patients presenting for colonoscopy within the UK Bowel Cancer Screening Programme (BCSP) is unknown. Terminal ileal intubation is not a prerequisite of the programme and usually not performed on a systematic basis. Anecdotally we became aware that ileal ulceration was a surprisingly common finding. We therefore decided to prospectively evaluate the incidence of ileal ulceration in sequential patients presenting for colonoscopy through the BCSP. Method All sequential patients being endoscoped by a single BCSP colonoscopist over a 28 month period from July 2012 were prospectively audited. All patients had been referred for colonoscopy on account of positive FOBs performed as part of the UK BCSP. Terminal ileal intubation was planned at the outset in all cases. If ileal ulceration was seen it was photographed and biopsied. Current symptoms, past medical and drug history was recorded in all cases. Histology was reported by BCSP pathologists, with all cases of ileal ulceration subsequently reviewed by a specialist GI pathologist. Results 351 sequential colonoscopies performed by a single BCSP colonoscopist (JNG). Terminal ileal intubation was achieved in 325/351 (92.6%) of cases. Endoscopic evidence of terminal ileal ulceration was found in 28/325 (8.6%) of cases where the ileum was intubated. Ulceration was confirmed on biopsy in 24/325 (7.4%) cases. 2/24 cases had previously diagnosed Crohn’s disease (1 on active follow-up, the other historical). 5/24 patients were taking regular NSAIDS. The remaining 17/325 (5.2%) with both endoscopic and histological evidence of terminal ileal ulceration had no known risk factors. Conclusion In this study, endoscopically and histologically confirmed ileal ulceration was a common finding occurring in 7.3% of cases. This is the first study to document these findings prospectively in a sequential cohort of BCSP patients where intubation of the terminal ileum was attempted in a systematic manner. The incidence is dramatically higher than that previously reported in non-BCSP cohorts. Some cases can be attributed to drug use with the remainder appearing likely to be either physiological or potentially represent Crohn’s disease. The clinical relevance of these findings is currently unknown though it is pertinent that many patients in this cohort either had symptoms or had been previously been investigated for IBS or a change in bowel habit. Disclosure of interest None Declared.

PWE-005 Outcomes from the first uk bowel cancer screening programme (bcsp) site: screening and surveillance experience since 2006

<h3>Introduction</h3> National BCSP screening for all 60–69 year olds commenced in 2006, and was extended to 60–74 year olds in 2010. The first site open was in Wolverhampton in July 2006. Previous trials had demonstrated the efficacy of population screening with the use of faecal occult blood test. We have previously shown that in the first two years of the BCSP downstaging of colorectal cancer in the screened group was demonstrated (45.3% Dukes A and 21.7% Dukes B).¹ <h3>Method</h3> Retrospective analysis of data from the first 7 years of the programme (August 2006 to December 2013) included demographics, screening outcomes (neoplasia and adenoma detection), pathological staging of cancers and colonoscopy quality indicators. Surveillance outcomes were reported on those patients eligible in the study period. <h3>Results</h3> During the study period (2006–13) 4506 colonoscopies were undertaken (63.4% Male; n = 2855). Mean caecal intubation rate was 97.1% and mean withdrawal time for normal procedures was 7.3 min. 355 cancers were detected (65.3% Male; n = 232). 62.5% of cancers were ‘early’ (23% Dukes A, 31.5% Dukes B) and 71.5% were left-sided (28% rectal, 37.4% sigmoid). 3699 adenomas were detected and the mean number of adenomas per procedure was 0.82. 37% (n = 1366) of these were 1 cm. The mean adenoma detection rate per colonoscopist was 43.25%. The high risk (n = 420) and intermediate risk (n = 768) adenomas were surveyed as per national guidance. In those high risk surveillance cases (n = 420) the detection of adenoma was seen in 31.4% (n = 132) of which 13.6% (n = 18) of them had adenomas greater than 1 cm. 0.47% (n = 3) of surveillance cases were found to have cancer suggestive of a potential post colonoscopy missed cancer. <h3>Conclusion</h3> These data confirm that a high quality screening colonoscopy service has been maintained since inception of the BCSP. Despite high quality indicators for endoscopic performance, surveillance has demonstrated missed adenoma and cancer still occur. Cancer staging data suggest a diminished benefit in the latter 5 years of the BCSP. <h3>Disclosure of interest</h3> None Declared. <h3>Reference</h3> Ellul P, Fogden E, Simpson CL, <i>et al</i>. Downstaging of colorectal cancer by the national bowel cancer screening programme in England: first round data from the first centre. Colorectal Dis. 12:420–422

PTH-025 Which patients tolerate unsedated colonoscopy? a uk bowel cancer screening centre experience

Introduction In the UK Bowel Cancer Screening Programme (BCSP), sedation doses and comfort scoring are used in quality assurance. There is debate whether we should offer unsedated colonoscopy, nitrous oxide being available in many units. This is a double edged sword; endoscopists are using less sedation and analgesia but potentially increase discomfort for patients. There is marked diversity in the Bradford and Airedale area with an approximate 20% South Asian population. We wanted to know if we could predict patients who would choose to have their colonoscopy unsedated. Previous studies within the Bradford and Airedale BCSP have shown differences in uptake related to ethnicity and deprivation indices. Our question was whether these also play a role in the tolerance of colonoscopy. Method Retrospective analyses of all BCSP cases performed by a single endoscopist at Bradford Royal Infirmary (BRI) were reviewed between February 2010 and April 2014. This endoscopist routinely offered a choice of sedation to all patients: 1. No medication but Fentanyl and then Midazolam if required 2. Fentanyl at the start then Midazolam if required 3. Combination of Fentanyl and Midazolam Data collected was gender, ethnicity, postcode and deprivation index, Fentanyl and Midazolam doses used. Results In total, 453 colonoscopies were performed. Midazolam was not used in 219 cases (48%). Neither drug was used in 20% of cases (80 Males, 9 Females). Only 5 Asian males and no Asian females had a drug-free procedure. In 130 cases (29%), Fentanyl was the only medication used. Just 7% of Asian females had Fentanyl only compared to 27% of Caucasian females. Use of both drugs was highest in Asian females (93%) compared to Caucasian females (67%). Analysis of deprivation index of patients using their postcode showed no difference in sedation uptake. Conclusion There was a clear difference in the use of sedation within the group. Several factors may influence patient choice regarding sedation. The first being language barriers; being offered unsedated colonoscopy may be erroneously interpreted as having no option of medication if it becomes uncomfortable. Choosing sedation may be driven by other cultural elements. Colonoscopy is an invasive procedure and may be seen as embarrassing or shameful, these fears are known barriers to screening uptake. Fear of pain and being diagnosed with cancer may also influence choice. However, some are quick to avoid medication when given a choice. Having no sedation or Fentanyl reduces the need for someone to collect or stay with the patient. This was seen more with those who lived on their own, not having to stay with family or friend post procedure. When offering all patients unsedated colonoscopy we should be mindful that not all will tolerate or want it. Disclosure of interest None Declared.