Performance of the faecal immunochemical test for the detection of colorectal neoplasms and the role of proton pump inhibitors in their diagnostic accuracy.

AIM: The faecal immunochemical test (FIT) is currently utilized in both symptomatic and screening populations, but little is known about factors that affect its performance. For example, proton pump inhibitor (PPI) therapy has been purported to increase false negative rates. This has significant implications given the extent of PPI prescriptions. The aim of this work was to evaluate the performance of the FIT for the detection of colorectal neoplasms and the impact of PPI therapy on its diagnostic accuracy. METHOD: Symptomatic patients referred on the suspected cancer pathway and those on polyp surveillance between 2015 and 2019 were approached to participate. Estimates of the accuracy of FIT at different cut-off levels in diagnosing colorectal neoplasms were made. Logistic regression was used to assess the effect of PPIs on the FIT results. RESULTS: A total of 667 participants were eligible for the final analysis. At a cut-off of 10 µg/g faeces, the overall sensitivity and specificity of FIT for the detection of colorectal cancer (CRC) was 0.85 (95% CI 0.71-0.94) and 0.81 (95% CI 0.78-0.84), respectively. For the detection of advanced neoplasia, the sensitivity was 0.70 (95% CI 0.58-0.79) and the specificity was 0.83 (95% CI 0.80-0.86). At higher thresholds, the sensitivity steadily declined whilst specificity increased. PPI therapy did not have a significant effect on performance of the FIT. CONCLUSION: FIT is a good rule-out test for the detection of CRC and advanced neoplasia at lower thresholds. PPI therapy does not appear to have an effect on its diagnostic performance.

Twitter debate: controversies in functional gastrointestinal disorders.

The new 'Controversies In…' series for the Frontline Gastroenterology Twitter debates addressed the difficult area of functional gastrointestinal disorders, facilitated by the former editor-in-chief Anton Emmanuel. Key topics discussed included distinguishing functional dyspepsia from genuine gastroparesis, when we should investigate for bile acid malabsorption, the current treatments for constipation-predominant irritable bowel syndrome and, importantly, how to manage consultations with complex patients presenting with functional bowel disease. The debate generated over a million impressions on twitter and this article aims to summarise the key educational points from the event.

Systematic review with meta-analysis of over 90 000 patients. Does fast-track review diagnose colorectal cancer earlier?

BACKGROUND: National UK data on colorectal cancer (CRC) stage at diagnosis is incomplete. Site-specific fast-track (2-week wait) cancer data are not collected directly by NHS England. Policy making based on these data alone can lead to inaccuracy. AIMS: To review available data on key outcomes (cancer conversion rate and stage at diagnosis) for the UK's lower gastrointestinal 2-week wait pathway. METHODS: A comprehensive literature search was conducted between 2000 and 2017. Primary outcomes were cancer conversion rate and cancer stage at diagnosis. Results were expressed as proportions with 95% CIs. A random effects model was used for meta-analysis; heterogeneity was assessed by I2 . RESULTS: Of 95 papers reviewed, 49 were included in analysis with a total study population of 93,655. Cancer conversion rate was 7.7% (95% CI: 6.9-8.5). The proportion presenting at Dukes A = 11.2% (95% CI 7.4-15.6), B = 36.7% (95% CI 30.8-42.8), C = 35.7% (95% CI: 30.8-40.8) and D = 11.1% (95% CI 7.3-15.5). No colonic pathology was diagnosed in 54.6% (95% CI: 46.2-62.8). CONCLUSIONS: Only 7.7% of patients referred by the 2-week wait pathway were found to have CRC. No beneficial effect on stage at diagnosis was found compared to non-2-week wait referral pathways. Over half of patients had no colonic pathology and detection of adenomas was very low. These results should prompt a reconsideration of the benefits of the 2-week wait pathway in CRC diagnosis and outcomes, with more focus on strategies to improve patient selection.

Time to endoscopy for acute upper gastrointestinal bleeding: Results from a prospective multicentre trainee-led audit.

Background: Endoscopy within 24 h of admission (early endoscopy) is a quality standard in acute upper gastrointestinal bleeding (AUGIB). We aimed to audit time to endoscopy outcomes and identify factors affecting delayed endoscopy (>24 h of admission). Methods: This prospective multicentre audit enrolled patients admitted with AUGIB who underwent inpatient endoscopy between November and December 2017. Analyses were performed to identify factors associated with delayed endoscopy, and to compare patient outcomes, including length of stay and mortality rates, between early and delayed endoscopy groups. Results: Across 348 patients from 20 centres, the median time to endoscopy was 21.2 h (IQR 12.0-35.7), comprising median admission to referral and referral to endoscopy times of 8.1 h (IQR 3.7-18.1) and 6.7 h (IQR 3.0-23.1), respectively. Early endoscopy was achieved in 58.9%, although this varied by centre (range: 31.0-87.5%, p = 0.002). On multivariable analysis, lower Glasgow-Blatchford score, delayed referral, admissions between 7:00 and 19:00 hours or via the emergency department were independent predictors of delayed endoscopy. Early endoscopy was associated with reduced length of stay (median difference 1 d; p = 0.004), but not 30-d mortality (p = 0.344). Conclusions: The majority of centres did not meet national standards for time to endoscopy. Strategic initiatives involving acute care services may be necessary to improve this outcome.

The Paddington International Virtual Chromoendoscopy Score in ulcerative colitis exhibits very good inter-rater agreement after computerized module training: a multicenter study across academic and community practice (with video).

BACKGROUND AND AIMS: Electronic virtual chromoendoscopy (EVC) can demonstrate ongoing disease activity in ulcerative colitis (UC), even when Mayo subscores suggest healing. However, applicability of EVC technology outside the expert setting has yet to be determined. METHODS: Fifteen participants across 5 centers reviewed a computerized training module outlining high-definition and EVC (iScan) colonoscopy modes. Interobserver agreement was then tested (Mayo score, Ulcerative Colitis Endoscopic Index of Severity [UCEIS], and the Paddington International Virtual Chromoendoscopy Score [PICaSSO] for UC), using a colonoscopy video library (30 cases reviewed pretraining and 30 post-training). Knowledge sustainability was retested in a second round (42 cases; 9/15 participants), 6 months after training provision. RESULTS: Pretraining intraclass correlation coefficients (ICC) were good for the Mayo endoscopic subscore (ICC, .775), UCEIS scoring erosions/ulcers (ICC, .770), and UCEIS overall (ICC, .786) and for mucosal (ICC, .754) and vascular components of PICaSSO (ICC, .622). For the vascular components of UCEIS, agreement was only moderate (ICC, .429) and did not enhance post-training (ICC, .417); conversely, use of PICaSSO improved post-training (mucosal ICC, .848; vascular, .746). Histologic correlation using the New York Mt. Sinai System was strong for both PICaSSO components (Spearman's ρ for mucosal: .925; vascular, .873; P < .001 for both). Moreover, accuracy in specifically discriminating quiescent from mild histologic strata was strongest for PICaSSO (area under the receiver operating characteristic curve [AUROC] for mucosal, .781; vascular, .715) compared with Mayo (AUROC, .708) and UCEIS (AUROC for UCEIS overall, .705; vascular, .562; bleeding, .645; erosions/ulcers, .696). Inter-rater reliability for PICaSSO was sustained by round 2 participants (round 1 and 2 ICC for mucosal, .873 and .869, respectively; vascular, .715 and .783, respectively), together with histologic correlation (ρ mucosal, .934; vascular, .938; P < .001 for both). CONCLUSIONS: PICaSSO demonstrates good interobserver agreement across all levels of experience, providing excellent correlation with histology. Given the ability to discriminate subtle endoscopic features, PICaSSO may be applied to refine stratified treatment paradigms for UC patients.