Bowel Screening Research Articles

Polokalama Fekumi ki he Kanisā 'o e Halanga-me'atokoní-Ko e vakai 'a e Tongá: Tongan New Zealanders' views on how to ensure the National Bowel Cancer Screening Programme works well for the Tongan community.

The National Bowel Screening Programme (NBSP) fails to deliver screening equitably to Pacific New Zealanders. This research explored Tongan New Zealanders' experiences of participating in the NBSP and their views on ensuring the programme works well for the Tongan community. In 2021, we conducted two talanoa focus groups with Tongan New Zealanders who had participated in the NBSP (n=26), recruited through a Pacific provider in Auckland. Participants were aged 60 or more and were Tongan born. Interviews with four Pacific experts working in the NBSP were also undertaken. Their views on the NBSP were explored and analysed using thematic analysis. While the research participants valued the opportunity to participate in the NBSP, they had many valuable insights about strengthening it, as did the Pacific experts. Key was a by Tongan, for Tongan service run by Tongan providers, one based on Tongan models of health and health promotion, Tongan values and ways of working, and using the Tongan language, which empowers Tongans to take control of their health. This research demonstrates critical elements of an effective, culturally appropriate and empowering NBSP for Tongans led by Tongan providers. If these findings are enacted, more effective delivery of bowel screening to Tongans will likely be enabled, reducing inequity in participation between Tongans and other New Zealanders. What is required is courage and political will to shift power and resources to ensure equitable outcomes in the NBSP, not only for Tongans but for all Pacific peoples.

Appendiceal Neoplasm in Conservatively Managed Acute Appendicitis: A Retrospective Observational Study.

Introduction Appendiceal neoplasms are more prevalent in patients ≥ 40 years old who present with complicated appendicitis, especially if managed conservatively. Routine interval appendicectomy is not recommended. Follow-up bowel screening using both a CT scan and colonoscopy is recommended. Following the COVID-19 pandemic, many units have increased their utilization of non-operative management of acute appendicitis (NOM).This provides an optimal population sample to study the incidence of unexpected appendiceal malignancy compared to a similar cohort that underwent operative management. The primary outcomes of interest include the incidence of appendiceal malignancy following NOM, efficacy of bowel screening, and rates of re-admission. Methods A retrospective, observational study on patients admitted with acute appendicitis from January 2020 to December 2021. All patients diagnosed with acute appendicitis aged 40 years and older were included in the study, while those under 40 or without a diagnosis of acute appendicitis were excluded. Results We had 211 cases of acute appendicitis. 125 (59%) of which were managed operatively, while 86 cases (41%) were managed NOM. We found six cases (7%) of appendiceal malignancy in the NOM cohort, compared to two cases (1.6%) in the operatively-managed cohort. A routine follow-up colonoscopy failed to reveal any sinister pathology. All six cases underwent interval appendicectomy through which the malignancy was detected. 39 cases (45%) of NOM had at least one episode of re-admission, with 32 (37%) of them being in the first year. Conclusion NOM of acute appendicitis in adults ≥ 40 years old is associated with an increase in unexpected appendiceal malignancy, none of which were detected on follow-up colonoscopy.We emphasize the need for closer surveillance and potentially more aggressive follow-up strategies, including routine interval appendicectomy, for older patients undergoing NOM of acute appendicitis.

Repeat Faecal Immunochemical Testing for Colorectal Cancer Detection in Symptomatic and Screening Patients: A Systematic Review and Meta-Analysis.

Faecal immunochemical testing (FIT) is widely used in bowel screening programmes and assessing symptomatic patients for suspected colorectal cancer (CRC). The evidence for single test performance of FIT in both settings is considerable; however, the use of a repeat test to increase sensitivity remains uncertain. We aimed to review what increase in test positivity would be generated by additional FITs, whether a repeated FIT detects previously missed CRC and advanced colorectal neoplasia (ACRN), and to estimate the sensitivity of double-FIT strategies to diagnose CRC and ACRN. A systematic search of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) was performed using key search terms. Studies reporting the use of more than one FIT in the same screening round or planned assessment of a single symptomatic patient episode were included. Studies were categorised by the reported study population into asymptomatic, mixed (cohorts of combined asymptomatic, symptomatic, or high-risk surveillance), or symptomatic cohorts. A total of 68 studies were included for analysis (39 asymptomatic, 21 mixed, 7 symptomatic, and 1 study with discrete asymptomatic and symptomatic data). At a threshold of 10 µg Hb/g, the two-test positivity ranged between 8.1 and 34.5%, with an increase from the second test of 3-9.2 percentage points. Four out of five studies comparing one versus two tests for diagnosing CRC at 10 µg Hb/g identified additional cases with the second test, with a minimum of 50% reduction in missed CRC. At a threshold of 20 µg Hb/g, the second test increased the positivity by 1.3-6.7 percentage points, with a two-test positivity of between 5.1 and 25.0%. Using a threshold of 20 µg Hb/g, five out of seven studies had a 25% reduction in missed CRC. A meta-analysis estimated the double-FIT sensitivity at 10 µg Hb/g for CRC in mixed-risk and symptomatic cohorts to be 94% and 98%, respectively. Repeated use of FIT helps to diagnose more cases of CRC with a moderate increase in positivity. A double-FIT strategy at 10 µg Hb/g in mixed and symptomatic cohorts has a very high sensitivity for CRC.

FP2.12 - 'To Evaluate Lower Threshold of Polyp Size for Tattooing Routinely, a Single Trust Observational Study.'

Abstract Aim The goal of the study is to establish the lowest polyp size for clinically effective tattooing routinely. Method Retrospective data collection of colonoscopy and flexible sigmoidoscopy for bowel screening and non-bowel screening patients; 450 patients underwent polypectomy of <20mm from September 2021 to September 2022 in MTW NHS Trust. Patients were included according to 'single patient single polyp' criteria. We excluded 20+ mm polyps, multiple polyp, known FAP, lynch syndrome and other genetic predisposed colorectal polyps. Histology was obtained from electronic patient records (Allscripts). SPSS version 25.0 was used for the statistical analysis, which also included ROC curve analysis and Chi-Square test. Results A total of 450 participants, 288 males (64.0%) and 162 females (36.0%), were enrolled. Polyp sizes: 0-9mm (42.2%) and 10-19mm (57.8%). 8.0% were tattooed. Polyps found in right- hemicolon, transverse, left-hemicolon, sigmoid and rectum accordingly 29.78%, 20.5%, 9.1%, 28.4% and 12.22%. Pedunculated polyps were found in 143 individuals (31.8%), while sessile polyps were observed in 256 individuals (56.9%). Furthermore, in histological analysis, 251 individuals (55.8%) exhibited tubular adenomas and the majority of the cohort (77.6%) presented with low-grade dysplasia. Malignant invasion was detected in 27 subjects (6%). Receiver operating system (ROC) curve analysis indicated that polyp size was a predictive factor for malignancy development, with a cut-off lower point identified at 8.5 mm. Conclusions The findings confirm the advice to tattoo polyps bigger than 8-9 mm to make tracing and follow- up easier.

Perceptions of the Impact of Comorbidity on the Bowel Cancer Screening Programme: Qualitative Study With Bowel Screening Participants and Staff.

The impact of multiple health conditions on bowel cancer screening is currently unknown. We explored the impact of multiple health conditions on bowel cancer screening perceptions, experience and clinical management decisions following a positive stool test. Semi-structured qualitative interviews were conducted remotely with Bowel Screening Wales staff (n = 16) stratified by regional location and roleand with screening participants (n = 19) stratified by age, gender and comorbidity. Interview topics were guided by the Common-Sense Model. Screening participants, regardless of comorbidity status, placed great emphasis on the importance of early detection of cancer and completing the bowel screening process. Screening staff emphasised comorbidities in the clinical decision-making process; however, screening participants had low awareness of the impact that comorbidities can have on bowel screening. Participants describe how the presence of multiple health conditions can mask potential bowel symptoms and influence beliefs about follow-up. Bowel screening staff try to individualise the service to meet participant needs. The potential mismatch in screening staff and participant awareness and expectations of the bowel screening and diagnostic process needs to be addressed. Clearer and more regular communication with screening participants could support the screening process, particularly for those with significant coexisting health conditions or facing time delays. The possible masking effects and misattribution of symptoms because of comorbidities highlightan opportunity for education and raising awareness for screening participantsand a potential area of focus for discussions in clinical consultations and staff training. Project funding included costs for patients and public contributors to be compensated for their contributions to the project, in line with current standards. A patient and public contributor was involved in the design of the study, including protocol development, and the interpretation of key findings and implications for patients, which are subsequently reflected within the manuscript.

Survey of awareness and beliefs about cancer (ABC) in Tehran Province, Iran

IntroductionKnowledge, attitudes, and practices are essential measures for planning and evaluating cancer control programs. Little is known about these in Iran.MethodsWe conducted a population-based interview survey of adults aged 30–70 using the Farsi version of the Awareness and Beliefs about Cancer questionnaire in the capital province of Tehran, Iran, 2019. We calculated weighted estimates of levels of cancer knowledge, attitudes, and practices to allow for different selection probabilities and nonresponse. We used multivariate logistic regression to understand demographic factors associated with bowel, cervix, and breast screening practices.ResultsWe interviewed 736 men and 744 women. The mean number of recalled cancer warning signs was less than one; 57.7% could not recall any cancer warning signs. Participants recognized 5.6 out of 11 early cancer warning signs and 8.8 of 13 cancer risk factors. Most (82.7%) did not know that HPV infection was a cancer risk factor. Approximately, half had negative attitudes towards cancer treatment, but over 80% had positive attitudes towards the effectiveness of screening for improving survival. Colorectal, breast, and cervical screening rates were 24%, 42%, and 49%, respectively. Higher socioeconomic status increased the odds of taking up screening for cancer. Women aged 60–70 were less likely to report taking up breast and cervical screening than younger women.DiscussionThe Iranian population has poor awareness and negative attitudes about cancer, and participation in screening programs is low. Public awareness and early detection of cancer should be promoted in Iran.

Abstract 4771: Assessment of Ki67 proliferation index in pre-malignant colonic adenomas: Implication for new biomarker testing to predict metachronous disease (The INCISE project)

Abstract Approximately 40% of patients are found to have polyps at bowel screening colonoscopy, which are associated with a higher risk of developing future polyps or colorectal cancer. The British Society of Gastroenterology 2020 (BSG20) guidelines stratify patients into high/low risk of metachronous disease, using the size, dysplasia, and number of polyps found at index colonoscopy. This study aims to explore the prognostic significance of Ki67 proliferation percentages in adenomatous polyps, with metachronous disease. Tissue microarray (TMA) was constructed from 1201 index adenomatous polyps with representative cores of basal and luminal adenomatous epithelia. 67% patients were identified as high risk at index colonoscopy. The median time to detect metachronous polyps was 55 months (range 6-72 months) with 56% of patients developing metachronous polyps by the end of follow-up. TMA was stained for Ki67 using immunohistochemistry. Ki67 proliferation percentages in adenomatous epithelia was quantified using QuPath. Data was split into training (n=830) and test (n=371) datasets. The Ki67 proliferation cutpoint was made using Survmine R package using the training dataset. X2 test was used to study associations with clinicopathological criteria and Kaplan survival analysis was used to assess Ki67 association with metachronous lesions. Ki67 percentages were higher in lumina than in basal adenomatous epithelium (median Ki67 were 63% & 48%; respectively). Total Ki67 percentages were computed by averaging luminal and basal values. Thresholds of 70%, 64% and 59% were employed to classify patients into low/high categories based on luminal, basal or total percentages; respectively. In the training cohort, high luminal, basal or total Ki67 were associated with metachronous lesions (p values 0.032, <0.001 and 0.006; respectively). Other associations were significant between luminal or total Ki67 and location of index polyps (p=0.017 & p=0.044; respectively), histology (p=0.019) and advanced future lesion status (p=0.002 & p<0.001; respectively). In multivariate cox regression analysis, high Ki67 was an independent prognostic factor for metachronous polyps (luminal Ki67 HR=1.28, CI: 1.052-1.560, p=0.014; basal Ki67 HR=1.639, CI: 1.313-2.046, p<0.001; total Ki67 HR=1.344, CI: 1.105-1.635, p=0.003) when adjusted to number of index polyps and BSG20 risk score. BSG20 risk score stratification of patients in terms of metachronous disease was improved when combined with luminal, basal or total Ki67 in the training datasets (all p<0.05). Prediction of metachronous disease by the combined groups was validated in the test cohort for luminal, basal and total Ki67 (all p<0.05). High Ki67 proliferation rates in adenomatous polyps are independently associated with the development of metachronous polyps and may help improve the BSG20 criteria. Citation Format: Gerard P. Lynch, Aula Ammar, Christopher Bigley, Mark Johnstone, Jakub Jawny, Hannah Morgan, Jennifer Hay, Noori Maka, Stephen McSorley, Joanne Edwards. Assessment of Ki67 proliferation index in pre-malignant colonic adenomas: Implication for new biomarker testing to predict metachronous disease (The INCISE project) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4771.

Primary care practice-based interventions and their effect on participation in population-based cancer screening programs: a systematic narrative review.

To provide a systematic synthesis of primary care practice-based interventions and their effect on participation in population-based cancer screening programs. Globally, population-based cancer screening programs (bowel, breast, and cervical) have sub-optimal participation rates. Primary healthcare workers (PHCWs) have an important role in facilitating a patient's decision to screen; however, barriers exist to their engagement. It remains unclear how to best optimize the role of PHCWs to increase screening participation. A comprehensive search was conducted from January 2010 until November 2023 in the following databases: Medline (OVID), EMBASE, and CINAHL. Data extraction, quality assessment, and synthesis were conducted. Studies were separated by whether they assessed the effect of a single-component or multi-component intervention and study type. Forty-nine studies were identified, of which 36 originated from the USA. Fifteen studies were investigations of single-component interventions, and 34 studies were of multi-component interventions. Interventions with a positive effect on screening participation were predominantly multi-component, and most included combinations of audit and feedback, provider reminders, practice-facilitated assessment and improvement, and patient education across all screening programs. Regarding bowel screening, provision of screening kits at point-of-care was an effective strategy to increase participation. Taking a 'whole-of-practice approach' and identifying a 'practice champion' were found to be contextual factors of effective interventions.The findings suggest that complex interventions comprised of practitioner-focused and patient-focused components are required to increase cancer screening participation in primary care settings. This study provides novel understanding as to what components and contextual factors should be included in primary care practice-based interventions.

A discrete choice experiment to understand public preferences and priorities for risk-stratified bowel cancer screening programmes in the UK

ObjectivePublic acceptability of bowel cancer screening programmes must be maintained, including if risk stratification is introduced. We aimed to describe and quantify preferences for different attributes of risk-stratified screening programmes amongst the UK population, focussing on who to invite for bowel screening. MethodsWe conducted a discrete choice experiment (DCE) including the following attributes: risk factors used to estimate bowel cancer risk (age plus/minus sex, lifestyle factors and genetics); personalisation of risk feedback; risk stratification strategy plus resource implications; default screening in the case of no risk information; number of deaths prevented by screening; and number experiencing physical harm from screening. We used the results of conditional logit regression models to estimate the importance of each attribute, willingness to trade-off between the attributes, and preferences for different programmes using contemporary risk scores and models. Results1196 respondents completed the survey, generating 21,528 DCE observations. Deaths prevented was the most influential attribute on respondents' decision-making (contributing to 58.8% of the choice), followed by harms experienced (15.9%). For every three additional deaths prevented, respondents were willing to accept an additional screening harm per 100,000 people. Risk factors and risk stratification strategy contributed to just 11.1% and 3.6% of the choice, respectively. Although the influence on decision-making was small, respondents favoured more personalised feedback. ConclusionsBowel cancer screening programmes that improve cancer outcomes, particularly by preventing more deaths amongst those screened, are most preferred by the public. Optimising risk prediction models, developing public communication, and readying infrastructure should be prioritised for implementation.

Interval colorectal cancers after negative faecal immunochemical test in the New Zealand Bowel Screening Pilot

ObjectiveEvaluate the diagnostic performance of faecal immunochemical test (FIT), identify risk factors for FIT-interval colorectal cancers (FIT-IC) and describe long-term outcomes of participants with colorectal cancers (CRC) in the New...

Varying faecal immunochemical test positivity thresholds impacts colorectal cancer detection

Abstract Background Colorectal cancer (CRC) is screened for by the faecal immunochemical test (FIT) in Ireland. The FIT positivity threshold in Ireland is 45 micrograms (µg) of haemoglobin per gram (g) of stool. FIT positivity thresholds influence both demand for screening colonoscopies and CRC detection rates through screening. This study aimed to assess the impact of varying FIT positivity thresholds on CRC detection rates through screening in Ireland. Methods This study used data from BowelScreen - The National Bowel Screening Programme, to retrospectively assess the impact of altering the FIT positivity threshold, adjusting it to correspond with neighbouring European countries, on CRC detection rates through screening in Ireland between 2013 and 2021. All analyses were conducted on Stata 17. Results 1,552 individuals were diagnosed with CRC in Ireland after a positive FIT performed through BowelScreen between 2013-2021. Adopting the same FIT positivity thresholds as the Netherlands (47µg/g), Scotland (80µg/g), England (120µg/g) and Wales (150µg/g) would have resulted in 21 (1.4%), 262 (17.1%), 458 (29.8%) and 556 (36.2%) fewer diagnoses of CRC through BowelScreen during this period, respectively. Additionally, increasing the positivity threshold to correspond with these countries would have resulted in between 1.7-41.9% fewer stage 1, between 1.0-30.9% fewer stage 2, between 1.4-32.9% fewer stage 3 and between 0-5.6% fewer stage 4 CRCs detected. Conclusions Changing the FIT positivity threshold in Ireland to correspond with that of other neighbouring European countries would have reduced the detection of CRC through screening to varying degrees. The detection of stage 1 CRCs would have been most greatly reduced, but up to almost a third of all stage 2 and stage 3 CRCs would not have been detected if some alternative, higher positivity thresholds were adopted. Key messages • Increasing the FIT positivity threshold in Ireland will need careful consideration to keep the optimum positive predictive value of a colonoscopy. • Lower stage 1-3 CRC detection rates may occur as a result.

Inequality in uptake of bowel cancer screening by deprivation, ethnicity and smoking status: cross-sectional study in 86850 citizens.

Survival from colorectal cancer depends on stage at detection. In England, bowel cancer mortality has historically been highest in deprived areas. During the initial stages of the COVID-19 pandemic, it was necessary to temporarily halt many screening programmes, which may have led to inequalities in uptake since screening restarted. Cross-sectional data from the Bristol, North Somerset and South Gloucestershire Systemwide Dataset were analyzed. Associations of baseline characteristics with uptake of bowel screening were examined using logistic regression. Amongst 86850 eligible adults aged 60-74years, 5261 had no screening record. There was little evidence of association between no screening and sex (adjusted odds ratio 0.95 (95% confidence interval 0.90, 1.02)). Absence of screening record was associated with deprivation (1.26 (1.14, 1.40) for the most compared with the least deprived groups), smoking (1.11 (1.04, 1.18)) compared with no smoking record and black (1.36 (1.09, 1.70)) and mixed (1.08 (1.01, 1.15)) ethnicity compared with white ethnicity. In a data set covering a whole NHS Integrated Care Board, there was evidence of lower uptake of bowel cancer screening in adults living in more deprived areas, of minority ethnic groups and who smoked. These findings may help focus community engagement work and inform research aimed at reducing inequalities.

Patients’ experience of using colonoscopy as a diagnostic test after a positive FOBT/FIT: a systematic review of the quantitative literature

ObjectivesFaecal occult blood testing (FOBT) and faecal immunochemical testing (FIT) are among the most used screening modalities for colorectal cancer (CRC). Colonoscopy is also widely used as a screening and...

Development and Validation of a Tool to Identify Anal Incontinence in Pregnant and Postnatal Women.

Neuromuscular and mechanical damage to the pelvic floor because of pregnancy and birth can result in anal incontinence. Pregnant and postnatal women are rarely screened for anal incontinence by clinicians who specialize in the care of these women, and no screening tool has been developed for routine use in these women. To develop and validate a tool for use in everyday clinical practice in the care of pregnant and postnatal women. The study includes 2 test phases with separate data sources. Phase I included test and retest phases of the Bowel-Screening Questionnaire in health professionals and women who were pregnant or had recently birthed (n = 45). Phase II included a pilot of the tool compared to 2 current scoring systems (n = 358). Large tertiary hospital in South Australia. Phase II: prospective recruitment of 358 prenatal parous women attending a first antenatal appointment. To evaluate the reliability and validity of the developed tool. Test-retest agreement in phase I was excellent for each of the 6 items, with each κ statistic being between 0.83 and 1.0. In phase II, agreement between new and existing tools was fair to good for the detection of anal incontinence symptoms addressed as a composite question (κ between 0.41 and 0.71). Anal incontinence was detected in 191 women (53%) using the new tool, and there was a lower prevalence reported using the Vaizey score (n = 118) and Wexner score (n = 129). Completion rates of the new tool were 99%, higher than both the Vaizey score (33%) and Wexner score (36%). Sample size limits the generalization of findings. The questionnaire is reliable and valid, reporting a high incidence of bowel incontinence, with predominant symptoms of rectal urgency and flatus as precursors for worsening function. ANTECEDENTES:El daño neuromuscular y mecánico del piso pélvico debido al embarazo y al parto puede resultar en incontinencia anal. Las mujeres embarazadas y puérperas rara vez son examinadas para la incontinencia anal por médicos que se especializan en el cuidado de estas mujeres, y no se ha desarrollado ninguna herramienta de detección para uso rutinario en estas mujeres.OBJETIVO:Desarrollar y validar una herramienta para uso en la práctica clínica diaria en el cuidado de las mujeres embarazadas y puérperas.FUENTES DE DATOS:El estudio incluye 2 fases de prueba con fuentes de datos separadas. Fase 1, fase test y retest del Bowel Screening Questionnaire en profesionales sanitarios y mujeres embarazadas o recién paridas (n = 45). La Fase 2 incluyó una prueba piloto de la herramienta en comparación con dos sistemas de puntuación actuales (n = 358).ENTORNO CLINICO:Gran hospital terciario en el sur de Australia.PACIENTES:Fase 2: reclutamiento prospectivo de 358 mujeres con parto prenatal que asisten a una primera cita prenatal.PRINCIPALES MEDIDAS DE VALORACIÓN:Evaluar la confiabilidad y validez de la herramienta desarrollada.RESULTADOS:La concordancia test-retest en la fase 1 fue excelente para cada uno de los 6 ítems con cada estadística kappa entre 0,83 y 1,0. En la fase 2, el acuerdo entre las herramientas nuevas y las existentes fue regular a bueno para la detección de síntomas de incontinencia anal abordados como una pregunta compuesta (kappa entre 0,41 y 0,71). Se detectó incontinencia anal en 191 (53%) de las mujeres que utilizaban la nueva herramienta, y se notificó una prevalencia más baja utilizando la puntuación de Vaizey (n = 118) y la puntuación de Wexner (n = 129). Las tasas de finalización de la nueva herramienta fueron del 99%, más altas que la puntuación de Vaizey (33%) y las puntuaciones de Wexner (36%).LIMITACIONES:El tamaño de la muestra limita la generalización de los hallazgos.CONCLUSIONES:El cuestionario es confiable y válido reportando una alta incidencia de incontinencia intestinal, con síntomas predominantes de urgencia rectal y flatos como precursores del empeoramiento de la función. (Traducción-Dr. Ingrid Melo ).

Interval cancers in a national colorectal screening programme based on faecal immunochemical testing: Implications for faecal haemoglobin concentration threshold and sex inequality.

To compare interval cancer proportions (ICP) in the faecal immunochemical test (FIT)-based Scottish Bowel Screening Programme (SBoSP) with the former guaiac faecal occult blood test (gFOBT)-based SBoSP and investigate associations between interval cancer (IC) and faecal haemoglobin concentration (f-Hb) threshold, sex, age, deprivation, site, and stage. The ICP data from first year of the FIT-based SBoSP and the penultimate year of the gFOBT-based SBoSP were compared in a prospective cohort design. With FIT, 801 colorectal cancers (CRCs) were screen detected (SDC), 802 were in non-participants, 548 were ICs, 39 were colonoscopy missed and 72 were diagnosed after incomplete screening; with gFOBT: 540, 904, 556, 45, and 13, respectively. FIT had a significantly higher proportion of SDC compared to IC than gFOBT. For FIT and gFOBT, ICP was significantly higher in women than men. As f-Hb threshold increased, ICP increased and, for any f-Hb threshold for men, a lower threshold was required for comparable ICP in women. In Scotland, the current threshold of ≥80 µg Hb/g faeces would have to be lowered to ≥40 µg Hb/g faeces for women to achieve sex equality for ICP. In the FIT-based SBoSP, there were four times as many stage I SDC than IC. This was reversed in advanced stages, with twice as many stage IV CRC diagnosed as IC versus SDC. Reducing the numbers of IC requires lowering the f-Hb threshold. Using different f-Hb thresholds for women and men could eliminate the sex disparity, but with additional colonoscopy.

Improved stage and survival for patients in the Aotearoa New Zealand colorectal cancer screening program 2012-2019.

Colorectal cancer (CRC) screening was introduced in Aotearoa New Zealand at Waitematā District Health Board (WDHB) in late 2011. This study reviewed patterns of disease, treatment received, and survival of patients with national bowel screening program (NBSP)-detected CRC versus non-NBSP patients at WDHB 2012-2019. Data collected retrospectively for all patients with adenocarcinoma of the colon or rectum at WDHB 2012-2019. Patient records were manually reviewed. Chi-square, Fisher's exact test and the Mann Whitney U-test used as appropriate. Kaplan-Meier and Cox proportional hazards regression modelling for survival analysis. 1667 patients included (360 NBSP and 1307 non-NBSP). 863 (51.8%) were male. Median age at diagnosis 73 years (range 21-100); NBSP patients were younger (median 68 vs. 76 years, P < 0.001). NBSP patients had significantly lower T, N, M and overall TNM stage than non-BSP patients. Median survival estimate on Kaplan-Meier analysis was 94 months for all patients. Statistically significant (P < 0.05) predictors of mortality on multi-variate regression analysis included increasing overall TNM stage compared with stage I (stage II HR 1.63 (95% CI 1.14-2.34), stage III HR 2.86 (95% CI 2.03-4.03), stage IV HR 7.73 (95% CI 5.59-10.68)), diagnosis within NBSP (HR 0.51 (95% CI 0.37-0.71)), increasing age in years (HR 1.03 (95% CI 1.02-1.03)), urgent/emergency surgery (HR 1.66 (95% CI 1.36-2.01)) and formal resection of primary tumour (HR 0.31 (95% CI 0.25-0.38)). Patients diagnosed within the Aotearoa New Zealand NBSP were found to be younger and have earlier stage CRC. Diagnosis within the NBSP is an independent predictor of survival for patients with CRC.

WS08.04 Faecal Immunochemical Testing – ‘FIT’ for purpose for bowel screening in older cystic fibrosis patients?

Objectives: Cystic Fibrosis (CF) patients have a high incidence of premalignant polyps and colorectal cancer (CRC). We aimed to evaluate the incidence of CRC at our centre and establish the diagnostic yield of colonoscopy and faecal immunochemical testing (FIT) in CF patients.

NATIONAL SCREENING PROGRAM FOR COLORECTAL CANCER

Colorectal Cancer:Colorectal cancer is one of the preventable cancers in humans. From a simple polyp to cancer, it is a long journey and gives us a window of opportunity to intervene and prevent it. Historically, Pakistan has been considered a low-prevalence country for colorectal cancer but changing epidemiological patterns dictate that we should think of implementing bowel screening programs for early detection and risk reduction. More than 1.9 million new colorectal cancer (including anus) cases and 935,000 deaths were estimated to occur in 2020, representing about one in 10 cancer cases and deaths. (Globocan 2020). Colorectal Cancer is the 3rd most common cancer among men and 2nd most common cancer among women, worldwide. (1). CRC mortality rates have been declining in the USA and Canada, whereas in many countries like Latin America and the Caribbean (LAC), the mortality rates are increasing. This difference between Canada and the US with the rest of the countries in the Americas serves as an indication of differences that may exist in health care, including CRC screening, early detection, and treatment. There are perhaps lessons that can be learned from the USA and Canada experiences with CRC programs that can be used to address the growing burden of CRC in LAC&#x0D;

Improved use of faecal immunochemical tests for haemoglobin in the Scottish bowel screening programme.

This study aimed to develop a risk-scoring model in the Scottish Bowel Screening Programme incorporating faecal haemoglobin concentration with other risk factors for colorectal cancer. Data were collected for all individuals invited to participate in the Scottish Bowel Screening Programme between November 2017 and March 2018 including faecal haemoglobin concentration, age, sex, National Health Service Board, socioeconomic status, and screening history. Linkage with The Scottish Cancer Registry identified all screening participants diagnosed with colorectal cancer. Logistic regression was performed to identify which factors demonstrated significant association with colorectal cancer and could be used in the development of a risk-scoring model. Of 232,076 screening participants, 427 had colorectal cancer: 286 diagnosed following a screening colonoscopy and 141 arising after a negative screening test result giving an interval cancer proportion of 33.0%. Only faecal haemoglobin concentration and age showed a statistically significant association with colorectal cancer. Interval cancer proportion increased with age and was higher in women (38.1%) than men (27.5%). If positivity in women were mirrored in men at each age quintile interval cancer proportion would still have remained higher in women (33.2%). Moreover, an additional 1201 colonoscopies would be required to detect 11 colorectal cancers. Development of a risk scoring model using early data from the Scottish Bowel Screening Programme was not feasible due to most variables showing insignificant association with colorectal cancer. Tailoring the faecal haemoglobin concentration threshold according to age could help to diminish some of the disparity in interval cancer proportion between women and men. Strategies to achieve sex equality using faecal haemoglobin concentration thresholds depend considerably on which variable is selected for equivalency and this requires further exploration.

Risk stratification for the detection of metachronous polyps after bowel screening polypectomy: clinical outcomes from the Integrated Technologies for Improved Polyp Surveillance (INCISE) study cohort.

After colorectal polypectomy, 20-50 per cent of patients develop metachronous polyps and some have increased colorectal cancer risk. British Society of Gastroenterology (BSG) 2020 guidelines recommend surveillance colonoscopy for high-risk patients based on index pathology. The aim of this study was to evaluate metachronous lesion outcome using BSG 2020 criteria. A retrospective, multicentred study was conducted including patients who had polypectomy during screening colonoscopy (2009-2016) followed by surveillance. Demographics, index pathology, and BSG 2020 risk criteria were compared with regard to metachronous lesion pathology (non-advanced versus advanced lesions) and timing of detection (early versus late). Advanced lesions were defined as adenomas/serrated polyps greater than or equal to 10 mm, high-grade dysplasia, serrated polyps with dysplasia, or colorectal cancer, and late lesions those detected greater than 2 years after the index procedure. Of 3090 eligible patients, 2643 were included. Among these, retrospective BSG 2020 application would have excluded 51.5 per cent from surveillance. After a median of 36 months, the advanced polyp/colorectal cancer rate in BSG 2020 high-risk patients was 16.3 versus 13.0 per cent in low-risk patients. Older age (P = 0.008) correlated with advanced metachronous lesions. Male sex, greater than five polyps, and BSG 2020 high-risk criteria correlated with non-advanced and advanced lesions (P < 0.001). Older age (P < 0.001), villous features (P = 0.006), advanced index polyp (P = 0.020), and greater than five polyps (P < 0.001) correlated with early metachronous lesions. Male sex and BSG 2020 high-risk criteria correlated with early and late lesions (P < 0.001). On multivariable regression, increased polyp number (odds ratio (OR) 1.15 (95 per cent c.i. 1.07 to 1.25); P < 0.001) and villous features (OR 1.49 (95 per cent c.i. 1.05 to 2.10); P = 0.025) independently correlated with early advanced lesions. The rate of non-advanced and advanced metachronous polyps was higher in BSG 2020 high- versus low-risk patients (44.4 versus 35.4 per cent for non-advanced and 15.7 versus 11.8 per cent for advanced; P < 0.001), but the colorectal cancer rate was similar (0.6 versus 1.2 per cent). However, when examining only lesions detected greater than 2 years after the index colonoscopy in high- versus low-risk patients, no significant differences were observed (P = 0.140). BSG 2020 criteria correlated with metachronous polyps, but did not differentiate advanced and non-advanced lesions and were not predictive of late lesions.