British Society of Gastroenterology/Association of Coloproctology of Great Britain and Ireland/Public Health England post-polypectomy and post-colorectal cancer resection surveillance guidelines

The Fast Track FIT study: diagnostic accuracy of faecal immunochemical test for haemoglobin in patients with suspected colorectal cancer

BACKGROUND

The faecal immunochemical test (FIT) is now available to support clinicians in the assessment of patients at low risk of colorectal cancer (CRC) and within the bowel cancer screening programme.

AIM

To determine the diagnostic accuracy of FIT for CRC and clinically significant disease in patients referred as they were judged by their GP to fulfil National Institute for Health and Care Excellence guideline 12 (NG12) criteria for suspected CRC.

DESIGN AND SETTING

Patients referred from primary care with suspected CRC, meeting NG12 criteria, to 12 secondary care providers in Yorkshire and Humber were asked to complete a FIT before investigation.

METHOD

The diagnostic accuracy of FIT based on final diagnosis was evaluated using receiver operating characteristics analysis. This permitted a statistically optimal cut-off value for FIT to be determined based on the maximisation of sensitivity and specificity. Clinicians and patients were blinded to the FIT results.

RESULTS

In total, 5040 patients were fully evaluated and CRC was detected in 151 (3.0%). An optimal cut-off value of 19 µg Hb/g faeces for CRC was determined, giving a sensitivity of 85.4% (95% confidence interval [CI] = 78.8% to 90.6%) and specificity of 85.2% (95% CI = 84.1% to 86.2%). The negative predictive value at this cut-off value was 99.5% (95% CI = 99.2% to 99.7%) and the positive predictive value 15.1% (95% CI = 12.8% to 17.7%). Sensitivity and specificity of FIT for CRC and significant premalignant polyps at this cut-off value were 62.9% (95% CI = 57.5% to 68.0%) and 86.4% (95% CI = 85.4% to 87.4%), respectively; and when including all organic enteric disease were 35.7% (95% CI = 32.9% to 38.5%) and 88.6% (95% CI = 87.5% to 89.6%), respectively.

CONCLUSION

FIT used in patients fulfilling NG12 criteria should allow for a more personalised CRC risk assessment. FIT should permit effective, patient-centred decision-making to inform the need for, type, and timing of further investigation.

Risk of metachronous neoplastic lesions during post-polypectomy surveillance in individuals with advanced colorectal neoplasia at initial screening colonoscopy

BACKGROUND AND AIM

The evidence of associations between some types of advanced colorectal neoplasia (ACN) at baseline and the risk of metachronous neoplasia is inconsistent. This study aimed to elucidate the incidence of metachronous neoplasia during post-polypectomy surveillance in individuals with ACN at baseline and examine the risk factors for its high incidence.

METHODS

Data from individuals who underwent endoscopic resection for ACN and received surveillance colonoscopy were analyzed. Data from individuals with no neoplastic lesions at baseline were used as reference. The incidence of metachronous ACN and clinically significant neoplasia (ACN and nonadvanced adenomas sized ≥ 5 mm) were evaluated. Risk factors for the higher incidence of these lesions were examined in individuals with ACN at baseline.

RESULTS

During the median follow-up period of 61.8 months, metachronous ACN and nonadvanced adenomas sized ≥ 5 mm were detected in 9.6% and 32.4% of individuals with ACN at baseline (n = 136), respectively. The cumulative incidence of metachronous ACN and clinically significant neoplasia in individuals with ACN at baseline (3-year incidence: 5.5% and 16.9%, respectively) was higher than that in individuals with no neoplastic lesions at baseline (P < 0.01 for both). The presence of advanced histology at baseline, ≥ 5 neoplastic lesions at baseline, and family history of colorectal cancer were identified as risk factors for the higher incidence of clinically significant neoplasia.

CONCLUSIONS

The relatively high incidence of metachronous neoplasia in individuals with ACN at baseline was confirmed; careful surveillance is required for these individuals, particularly in those with the risk factors.

Novel Methods of Risk Stratifying Patients for Metachronous, Pre-Malignant Colorectal Polyps: A Systematic Review

INTRODUCTION

Despite conventional measures of future polyp risk (histology, dysplasia, size, number), surveillance places a burden on patients and colonoscopy services. We aimed to review novel risk stratification techniques.

METHODS

A systematic literature review was performed for studies using genomics, transcriptomics, IHC or microbiome as markers of metachronous polyp risk.

RESULTS

4165 papers underwent title, 303 abstract and 215 full paper review. 25 papers were included. 49 mutations/ SNPs/ haplotypes in 23 genes/ chromosomal regions (KRAS, APC, EGFR, COX1/2, IL23R, DRD2, CYP2C9/24A1/7A1, UGT1A6, ODC, ALOX12/15, PGDH, SRC, IGSF5, KCNS3, EPHB1/ KY, FAM188b, 3p24.1, 9q33.2, 13q33.2) correlated with metachronous adenoma / advanced adenoma risk. Expression levels of 6 proteins correlated with metachronous adenoma (p53, β-catenin, COX2, Adnab-9, ALDH1A1) or sessile serrated polyp (ANXA10) risk.

CONCLUSION

Although genomic and IHC markers correlated with metachronous polyp risk, it seems likely that a panel of novel markers will be required to refine this risk.

The inflammatory microenvironment in screen-detected premaligant adenomatous polyps: early results from the integrated technologies for improved polyp surveillance (INCISE) project

INTRODUCTION

Around 40% of patients who attend colonoscopy following a positive stool screening test have adenomatous polyps. Identifying which patients have a higher propensity for malignant transformation is currently poorly understood. The aim of the present study was to assess whether the type and intensity of inflammatory infiltrate differ between screen-detected adenomas with high-grade dysplasia (HGD) and low-grade dysplasia (LGD).

METHODS

A representative sample of 207 polyps from 134 individuals were included from a database of all patients with adenomas detected through the first round of the Scottish Bowel Screening Programme in NHS Greater Glasgow and Clyde (April 2009-April 2011). Inflammatory cell phenotype infiltrate was assessed by immunohistochemistry for CD3+, CD8+, CD45+ and CD68+ in a semi-quantitative manner at 20× resolution. Immune-cell infiltrate was graded as absent, weak, moderate or strong. Patient and polyp characteristics and inflammatory infiltrate were then compared between HGD and LGD polyps.

RESULTS

CD3+ infiltrate was significantly higher in HGD polyps compared to LGD polyps (74 vs. 69%; P < 0.05). CD8+ infiltrate was significantly higher in HGD polyps compared to LGD polyps (36 vs. 13%; P < 0.001) whereas CD45+ infiltrate was not significantly different (69 vs. 64%; P = 0.401). There was no significant difference in CD68+ infiltrate (P = 0.540) or total inflammatory cell infiltrate (calculated from CD3+ and CD68+) (P = 0.226).

CONCLUSIONS

This study reports an increase in CD3+ and CD8+ infiltrate in HGD colonic adenomas when compared to LGD adenomas. It may therefore have a use in the prognostic stratification and treatment of dysplastic polyps.

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.

Clinical Features and Predictors of Dysplasia in Proximal Sessile Serrated Lesions

BACKGROUND/AIMS

Proximal colorectal cancers (CRCs) account for up to half of CRCs. Sessile serrated lesions (SSLs) are precursors to CRC. Proximal location and presence of dysplasia in SSLs predict higher risks of progression to cancer. The prevalence of dysplasia in proximal SSLs (pSSLs) and clinical characteristics of dysplastic pSSLs are not well studied.

METHODS

Endoscopically resected colonic polyps at our center between January 2016 and December 2017 were screened for pSSLs. Data of patients with at least one pSSL were retrieved and clinicopathological features of pSSLs were analysed. pSSLs with and without dysplasia were compared for associations.

RESULTS

Ninety pSSLs were identified, 45 of which had dysplasia giving a prevalence of 50.0%. Older age (65.9 years vs. 60.1 years, p=0.034) was associated with the presence of dysplasia. Twelve pSSLs were 10 mm or larger. After adjusting for age, pSSLs ≥10 mm had an adjusted odds ratio of 5.98 (95% confidence interval, 1.21-29.6) of having dysplasia compared with smaller pSSLs.

CONCLUSION

In our cohort of pSSLs, the prevalence of dysplasia is high at 50.0% and is associated with lesion size ≥10 mm. Endoscopic resection for all proximal serrated lesions should be en-bloc to facilitate accurate histopathological examination for dysplasia as its presence warrants shorter surveillance intervals.

Russell Body Lesions of the Colon: Case Report and Literature Review

Russell bodies (RB) are rare manifestations within the lower gastrointestinal tract. To date, there are only three other reported cases of RB lesions of the colon; two were polyps, and the third was a case of a multifocal RB lesion of the gastrointestinal tract. This paper reports a case of a tubulovillous adenoma with RB of the sigmoid colon in a patient diagnosed incidentally as part of the UK National Health Service Bowel Cancer Screening Programme. A thorough hematological investigation is required to exclude hematological malignancies because of its association with plasma cell neoplasm. These lesions should undergo clonality analysis to exclude the monoclonal proliferation of plasma cells. Ideally, a bone marrow aspirate and investigations for amyloidosis should be performed to exclude underlying hematological malignancies.

Exploring polyps to colon carcinoma voyage: can blocking the crossroad halt the sequence?

Colorectal cancer is an important public health concern leading to significant cancer associate mortality. A vast majority of colon cancer arises from polyp which later follows adenoma, adenocarcinoma, and carcinoma sequence. This whole process takes several years to complete and recent genomic and proteomic technologies are identifying several targets involved in each step of polyp to carcinoma transformation in a large number of studies. Current text presents interaction network of targets involved in polyp to carcinoma transformation. In addition, important targets involved in each step according to network biological parameters are also presented. The functional overrepresentation analysis of each step targets and common top biological processes and pathways involved in carcinoma indicate several insights about this whole mechanism. Interaction networks indicate TP53, AKT1, GAPDH, INS, EGFR, and ALB as the most important targets commonly involved in polyp to carcinoma sequence. Though several important pathways are known to be involved in CRC, the central common involvement of PI3K-AKT indicates its potential for devising CRC management strategies. The common and central targets and pathways involved in polyp to carcinoma progression can shed light on its mechanism and potential management strategies. The data-driven approach aims to add valuable inputs to the mechanism of the years-long polyp-carcinoma sequence.

Post-polypectomy surveillance colonoscopy: Comparison of the updated guidelines

Background

Recently, three updated guidelines for post‐polypectomy colonoscopy surveillance (PPCS) have been published. These guidelines are based on a comprehensive summary of the literature, while some recommendations are similar, different surveillance intervals are recommended after detection of specific types of polyps.

Aim

In this review, we aimed to compare and contrast these recommendations.

Methods

The updated guidelines for PPCS were reviewed and the recommendations were compared.

Results

For patients with 1–4 adenomas <10 mm with low‐grade dysplasia, irrespective of villous components, or 1–4 serrated polyps <10 mm without dysplasia, the European Society of Gastrointestinal Endoscopy (ESGE) and British Society of Gastroenterology (BSG), the Association of Coloproctology of Great Britain and Ireland (ACPGBI) and Public Health England (PHE) (BSG/ACPGBI/PHE) guidelines do not recommend colonoscopic surveillance and instead recommend that the participate in routine CRC screening program (typically based on the fecal immunochemical test), while the USMSTF recommends surveillance colonoscopies 7–10 years after diagnosis of 1–2 tubular adenomas <10 mm and 3–5 years for 3–4 tubular adenomas of the same size. The USMSTF define adenomas with tubulovillous or villous histology as high‐risk adenomas; thus, surveillance colonoscopy is recommended after 3 years. However, the ESGE and BSG do not consider such histology as a criterion for repeating colonoscopy at this short interval. For patients with 1–2 sessile serrated polyps (SSPs) <10 mm and those with 3–4 SSPs <10 mm, the USMSTF recommends surveillance colonosocopy after 5–10 and 3–5 years, respectively.

Use of ColonFlag score for prioritisation of endoscopy in colorectal cancer

OBJECTIVE

Colorectal cancer (CRC) is the fourth most common cancer in UK. Symptomatic patients are referred via an urgent pathway and although most are investigated with colonoscopy <4% are diagnosed with cancer. There is therefore a need for a suitable triage tool to prioritise investigations. This study retrospectively examined performance of various triage tools in patients awaiting investigation on the urgent lower gastrointestinal cancer pathway DESIGN: All patients over 40 years of age on the urgent pathway awaiting investigation for suspected CRC on 1 May were included. After 6 months, outcomes were evaluated and the performance of the faecal immunochemical test (FIT), faecal haemoglobin concentration, age and sex test (FAST) and the artificial intelligence algorithm ColonFlag were examined.

RESULTS

532 completed investigations and received a diagnosis; 15 had CRC. 388 had a valid FIT result, of whom 11 had CRC; FAST Score ≥4.5 had sensitivity of 72.7%, specificity of 80.6% and would have failed to detect three tumours. Faecal haemoglobin (f-Hb) at cut-off of 10 µg/g and ColonFlag had equal sensitivity of 81.82%, ColonFlag had greater specificity 73.47%, compared with 64.99%. Both tests would have failed to detect two tumours but not in the same patients; when used in combination, sensitivity and specificity were 100% and 49.4%. When ColonFlag was applied to the cohort of 532, an additional four tumours would have been detected in patients without a valid FIT.

CONCLUSION

This study showed ColonFlag to have equal sensitivity and greater specificity than f-Hb at a cut-off of 10 µg/g as a triage tool for CRC.

Effect of water exchange method on adenoma miss rate of patients undergoing selective polypectomy: A randomized controlled trial

BACKGROUND

Adenomas may be missed in up to 40% of screening colonoscopies. Although the water exchange (WE) method can improve ADR, as shown in several RCTs, it remains uncertain whether it can increase the detection of missing adenomas compared with standard air-insufflated (AI) colonoscopy.

METHODS

Patients aged 18-80 years who underwent selective polypectomy were randomly allocated to the WE or AI group. The primary endpoint was the adenoma miss rate (AMR), defined as the number of patients with one or more additional adenomas during the polypectomy procedure divided by the total number of patients in each group.

RESULTS

A total of 450 patients were enrolled, with 225 in each group. The overall AMRs were 45.8% (103/225) in the WE group and 35.6% (80/225) in the AI group (p = 0.035). More patients in the WE group had at least one missed adenoma in the proximal colon (38.2% vs 24.4%, p = 0.002). The adenoma-level miss rate was also higher in the WE group than in the AI group (35.1% vs 29.0%, p = 0.036). Subgroup analysis showed that patients in the WE group had more missed adenomas located in the proximal colon or with flat shapes.

CONCLUSIONS

This study confirmed that substantial adenomas were missed in patients undergoing selective polypectomy. The WE method significantly improved the detection of missed adenomas, especially those located in the proximal colon or with flat shapes. (ClnicalTrials.gov number: NCT02880748).

Revising the European Society of Gastrointestinal Endoscopy (ESGE) research priorities: a research progress update

BACKGROUND

One of the aims of the European Society of Gastrointestinal Endoscopy (ESGE) is to encourage high quality endoscopic research at a European level. In 2016, the ESGE research committee published a set of research priorities. As endoscopic research is flourishing, we aimed to review the literature and determine whether endoscopic research over the last 4 years had managed to address any of our previously published priorities.

METHODS

As the previously published priorities were grouped under seven different domains, a working party with at least two European experts was created for each domain to review all the priorities under that domain. A structured review form was developed to standardize the review process. The group conducted an extensive literature search relevant to each of the priorities and then graded the priorities into three categories: (1) no longer a priority (well-designed trial, incorporated in national/international guidelines or adopted in routine clinical practice); (2) remains a priority (i. e. the above criterion was not met); (3) redefine the existing priority (i. e. the priority was too vague with the research question not clearly defined).

RESULTS

The previous ESGE research priorities document published in 2016 had 26 research priorities under seven domains. Our review of these priorities has resulted in seven priorities being removed from the list, one priority being partially removed, another seven being redefined to make them more precise, with eleven priorities remaining unchanged. This is a reflection of a rapid surge in endoscopic research, resulting in 27 % of research questions having already been answered and another 27 % requiring redefinition.

CONCLUSIONS

Our extensive review process has led to the removal of seven research priorities from the previous (2016) list, leaving 19 research priorities that have been redefined to make them more precise and relevant for researchers and funding bodies to target.

Risk of Colorectal Cancer and Cancer Related Mortality After Detection of Low-risk or High-risk Adenomas, Compared With No Adenoma, at Index Colonoscopy: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The risk of metachronous colorectal cancer (CRC) among patients with no adenomas, low-risk adenomas (LRAs), or high-risk adenomas (HRAs), detected at index colonoscopy, is unclear. We performed a systematic review and meta-analysis to compare incidence rates of metachronous CRC and CRC-related mortality after a baseline colonoscopy for each group.

METHODS

We searched the PubMed, Embase, Google Scholar, and Cochrane databases for studies that reported the incidence of CRC and adenoma characteristics after colonoscopy. The primary outcome was odds of metachronous CRC and CRC-related mortality per 10,000 person-years of follow-up after baseline colonoscopy for all the groups.

RESULTS

Our final analysis included 12 studies with 510,019 patients (mean age, 59.2 ± 2.6 years; 55% male; mean duration of follow up, 8.5 ± 3.3 years). The incidence of CRC per 10,000 person-years was marginally higher for patients with LRAs compared to those with no adenomas (4.5 vs 3.4; odds ratio [OR], 1.26; 95% CI, 1.06-1.51; I²=0), but significantly higher for patients with HRAs compared to those with no adenoma ( 13.8 vs 3.4; odds ratio [OR], 2.92; 95% CI, 2.31-3.69; I²=0 ) and patients with HRAs compared to LRAs (13.81 vs 4.5; OR, 2.35; 95% CI, 1.72-3.20; I²=55%). However, the CRC-related mortality per 10,000 person-years did not differ significantly for patients with LRAs compared to no adenomas (OR, 1.15; 95% CI, 0.76-1.74; I²=0) but was significantly higher in persons with HRAs compared with LRAs (OR, 2.48; 95% CI, 1.30-4.75; I²=38%) and no adenomas (OR, 2.69; 95% CI, 1.87-3.87; I²=0).

CONCLUSIONS

The results of this systematic review and meta-analysis demonstrate that the risk of metachronous CRC and mortality is significantly higher for patients with HRAs, but this risk is very low in patients with LRAs, comparable to patients with no adenomas. Follow-up of patients with LRAs detected at index colonoscopy should be the same as for persons with no adenomas.

Optimization of the surveillance strategy in patients with colorectal adenomas: A combination of clinical parameters and index colonoscopy findings

BACKGROUND AND AIM

In addition to index colonoscopy findings, demographic parameters including age are associated with the risk of metachronous advanced colorectal neoplasia. Here, we aimed to develop a risk scoring model for predicting advanced colorectal neoplasia (ACRN) during surveillance using a combination of clinical factors and index colonoscopy findings.

METHODS

Patients who underwent the removal of one or more adenomas and surveillance colonoscopy were included. A risk scoring model for ACRN was developed using the Cox proportional hazard model. Surveillance interval was determined as a time point exceeding 4% of the cumulative ACRN incidence in each risk group.

RESULTS

Of 9591 participants, 4725 and 4866 were randomly allocated to the derivation and validation cohorts, respectively. Age, abdominal obesity, advanced adenoma, and ≥ 3 adenomas at index colonoscopy were identified as risk factors for metachronous ACRN. Based on the regression coefficients, point scores were assigned as follows: age, 1 point (per 1 year); abdominal obesity, 10 points; advanced adenoma, 10 points; and ≥ 3 adenomas, 15 points. Patients were classified into high-risk (≥ 80 points), moderate-risk (50-79 points), and low-risk (30-49 points) groups. In the validation cohort, the high-risk and moderate-risk groups showed a higher risk of ACRN than the low-risk group (hazard ratio [95% confidence interval]: 7.11 [4.10-12.32] and 1.58 [1.09-2.30], respectively). Two-, 4-, and 5-year surveillance intervals were recommended for the high-risk, moderate-risk, and low-risk groups, respectively.

CONCLUSIONS

Our proposed model may facilitate effective risk stratification of ACRN during surveillance and the determination of appropriate surveillance intervals.

5-Aminosalicylic acid inhibits stem cell function in human adenoma-derived cells: implications for chemoprophylaxis in colorectal tumorigenesis

Background

Most colorectal cancers (CRC) arise sporadically from precursor lesions: colonic polyps. Polyp resection prevents progression to CRC. Risk of future polyps is proportional to the number and size of polyps detected at screening, allowing identification of high-risk individuals who may benefit from effective chemoprophylaxis. We aimed to investigate the potential of 5-aminosalicylic acid (5-ASA), a medication used in the treatment of ulcerative colitis, as a possible preventative agent for sporadic CRC.

Methods

Human colorectal adenoma (PC/AA/C1, S/AN/C1 and S/RG/C2), transformed adenoma PC/AA/C1/SB10 and carcinoma cell lines (LS174T and SW620) were treated with 5-ASA. The effect on growth in two- and three-dimensional (3D) culture, β-catenin transcriptional activity and on cancer stemness properties of the cells were investigated.

Results

5-ASA was shown, in vitro, to inhibit the growth of adenoma cells and suppress β-catenin transcriptional activity. Downregulation of β-catenin was found to repress expression of stem cell marker LGR5 (leucine-rich G protein-coupled receptor-5) and functionally suppress stemness in human adenoma and carcinoma cells using 3D models of tumorigenesis.

Conclusions

5-ASA can suppress the cancer stem phenotype in adenoma-derived cells. Affordable and well-tolerated, 5-ASA is an outstanding candidate as a chemoprophylactic medication to reduce the risk of colorectal polyps and CRC in those at high risk.

Future Prospects of Colorectal Cancer Screening: Characterizing Interval Cancers

Tumors that are not detected by screening tests are known as interval cancers and are diagnosed clinically after a negative result in the screening episode but before the next screening invitation. Clinical characteristics associated with interval colorectal cancers have been studied, but few molecular data are available that describe interval colorectal cancers. A better understanding of the clinical and biological characteristics associated with interval colorectal cancer may provide new insights into how to prevent this disease more effectively. This review aimed to summarize the current literature concerning interval colorectal cancer and its epidemiological, clinical, and molecular features.

A colorectal straight-to-test cancer pathway with general-practitioner-guided triage improves attainment of the 28-day diagnosis target and increases outpatient clinic capacity

AIM

This study investigates whether a straight-to-test (STT) colorectal cancer pathway improves attainment of the National Health Service (NHS) England 28-day Faster Diagnosis Standard and the effect of the pathway on reducing face-to-face outpatient clinic appointments. Patient satisfaction and the safety of a novel general practitioner (GP) led patient triage system regarding suitability for colonoscopy are also evaluated.

METHODS

This is an observational study of all patients managed via an STT colorectal cancer pathway between 1 September 2019 and 19 March 2020. Comparison is made with all patients referred on the suspected colorectal cancer pathway prior to implementation of the STT pathway from 1 January 2019 to 30 July 2019. Patient satisfaction with the STT pathway was assessed with a telephone-based questionnaire.

RESULTS

Attainment of the 28-day diagnosis target for all suspected colorectal cancer referrals improved following the establishment of the STT pathway (88% vs. 82%, P < 0.0001). From a potential total of 548 outpatient colorectal clinic appointments for patients on the STT pathway, 504 (92%) were avoided. In those eligible for the STT pathway, GP assessment of patients suitable for colonoscopy agreed with that of the colorectal department in 93% of cases. Of the 50 patients who undertook the satisfaction survey, 86% were satisfied or very satisfied with the pathway. No patient suffered adverse events as a result of their STT investigations.

CONCLUSION

An STT pathway for suspected colorectal cancer referrals with novel GP-led patient triage safely streamlines patients through the suspected colorectal cancer diagnostic pathway and significantly reduces requirement for face-to-face outpatient clinic attendance. This is achieved with high patient satisfaction.

Colorectal Cancer Screening and Surveillance for Non-Hereditary High-Risk Groups—Is It Time for a Re-Think?

Purpose of review

Colorectal cancer (CRC) is the second most common cause of cancer death worldwide, killing approximately 900,000 people each year. An individual’s risk of developing CRC is multi-factorial with known risk factors including increasing age, male sex, family history of CRC and raised body mass index. Population-based screening programmes for CRC exist in many countries, and in the United Kingdom (UK), screening is performed through the NHS Bowel Cancer Screening Programme (BCSP). Screening programmes offer a population-based approach for those at “average risk”, and do not typically offer enhanced screening for groups at increased risk. In the UK, such patients are managed via non-screening symptomatic services but in a non-systematic way.

Recent findings

There is growing evidence that conditions such as cystic fibrosis and a history of childhood cancer are associated with higher risk of CRC, and surveillance of these groups is advocated by some organizations; however, national recommendations do not exist in most countries.

Summary

We review the evidence for screening “high risk” groups not covered within most guidelines and discuss health economic issues requiring consideration acknowledging that the demand on colonoscopy services is already overwhelming.

Fibrotic Phenotype of Peritumour Mesenteric Adipose Tissue in Human Colon Cancer: A Potential Hallmark of Metastatic Properties

The impact of tumour associated stroma on cancer metastasis is an emerging field. However, cancer associated genes in peritumoral adipose tissue (pAT) in human colon cancer have not been explored. The aim of this study was to identify differentially expressed genes (DEGs) associated with cancer pathways in mesenteric pAT compared with adjacent adipose tissue. In total, nine patients with colon cancer pathological stage T2/T4 were employed in this study. DEGs were identified in 6 patients employing Nanostring PanCancer Pathway Panel and pathway enrichment analyses were performed. Differential expression of the 5 most up-regulated and 2 down regulated genes was validated with qRT-PCR. Results showed collagen type I alpha 1 chain (COL1A1) p = 0.007; secreted frizzled related protein (SFRP2) p = 0.057; fibroblast growth factor 7 (FGF7) not significant (ns); phospholipase A2, group IIA (PLA2G2A) ns; nerve growth factor receptor (NGFR) ns; lymphoid enhancer binding factor 1 (LEF1) p = 0.03; cadherin 1, Type 1, E-cadherin (epithelial) (CDH1) 0.09. Results have highlighted down-regulation of the Wingless/Integrated (Wnt) pathway in mesenteric pAT compared to distal adipose tissue. Highly upregulated genes in mesenteric pAT were involved in extracellular matrix (ECM)-receptor interactions and focal adhesion. Highly down regulated genes were involved in the cell cycle. Immunohistochemistry revealed differential distribution of COL1A1 showing maximum levels in tumour tissue and gradually decreasing in distant adipose tissue. COL1A1 and down regulation of Wnt pathway may have a role in local invasion and distant metastasis. COL1A1 may represent a stromal prognostic biomarker and therapeutic target in colon cancer.

Metachronous neoplasms in patients with laterally spreading tumours during surveillance

Background

Laterally spreading tumours represent a major challenge for endoscopic detection and resection.

Objective

To examine synchronous and metachronous neoplasms in patients with laterally spreading tumours.

Methods

We prospectively collected colonoscopy and histopathology data from patients who underwent colonoscopy in our centre at up to 6 years' follow‐up. Post‐resection surveillance outcomes between laterally spreading tumours, flat colorectal neoplasms 10 mm or greater, and large polypoid colorectal neoplasms, polypoid colorectal neoplasms 10 mm or greater, were compared.

Results

Between 2008 and 2012, 8120 patients underwent colonoscopy for symptoms (84.6%), screening (6.7%) or surveillance (8.7%). At baseline, 151 patients had adenomatous laterally spreading tumours and 566 patients had adenomatous large polypoid colorectal neoplasms. Laterally spreading tumour patients had more synchronous colorectal neoplasms than large polypoid colorectal neoplasm patients (mean 3.34 vs. 2.34, p < 0.001). Laterally spreading tumour patients significantly more often developed metachronous colorectal neoplasms (71.6% vs. 54.2%, p = 0.0498) and colorectal neoplasms with high grade dysplasia/submucosal invasion than large polypoid colorectal neoplasm patients (36.4% vs. 15.8%, p < 0.001). After correction for age and gender, laterally spreading tumour patients were more likely than large polypoid colorectal neoplasm patients to develop a colorectal neoplasm with high grade dysplasia or submucosal invasion (hazard ratio 2.9, 95% confidence interval 1.8–4.6). The risk of metachronous colorectal cancer was not significantly different in laterally spreading tumours compared to large polypoid colorectal neoplasm patients.

Conclusion

Patients with laterally spreading tumours developed more metachronous colorectal neoplasms with high grade dysplasia/submucosal invasion than large polypoid colorectal neoplasm patients. Based on these findings endoscopic treatment and surveillance recommendations for patients with laterally spreading tumours should be optimised.

Summarize the established knowledge on this subject

Laterally spreading tumours (LSTs) are a heterogeneous group of large, predominantly benign flat neoplasms that can be endoscopically treated, requiring additional time and expertise

LSTs consist of different endoscopic subtypes which are predictive of the risk of submucosal invasion (SMI)

Patients with LSTs harbour more synchronous neoplasms than patients with large polypoid colorectal neoplasms (LP‐CRNs)

What are the significant and/or new findings of this study?

Patients with LSTs more frequently have metachronous neoplasms than patients with LP‐CRNs, justifying strict surveillance

LSTs can be effectively managed by conventional endoscopic resections in most cases

Comparison of Risk of Metachronous Advanced Colorectal Neoplasia in Patients with Sporadic Adenomas Aged < 50 Versus ≥ 50 years: A Systematic Review and Meta-Analysis

No specific recommendations are available for the surveillance of young patients aged <50 years undergoing polypectomy. We aimed to compare the risk of metachronous advanced colorectal neoplasia (ACRN) between patients aged ≥50 years and those aged <50 years who underwent polypectomy. Studies published between January 1980 and June 2020 that examined the risk of metachronous ACRN were searched. We performed a meta-analysis for the metachronous ACRN risk in patients with sporadic colorectal adenomas according to the age groups (≥50 vs. <50 years). Eight individual studies were included in the meta-analysis. The risk of metachronous ACRN was higher in patients aged ≥50 years than in those aged <50 years without significant heterogeneity (odds ratio (OR) (95% CI): 1.62 (1.34–1.96), I² = 14%). The impact of the age group on the risk of metachronous ACRN was identified in both the low-risk (LRA) and high-risk (HRA) adenoma groups (≥50 vs. <50 years: LRA, OR 1.88 (95% CI 1.30–2.70); HRA, OR 1.50 [95% CI 1.13–2.00]). In conclusion, patients aged <50 years had a lower risk of metachronous ACRN than older patients. Young patients with sporadic adenomas do not require more intensive surveillance; rather, the surveillance interval may be extended in these patients.

The spectrum of serrated colorectal lesions-new entities and unanswered questions

Hyperplastic polyps (HPs) of the colon and rectum were historically thought not to be associated with an increased risk of development of colorectal cancer (CRC). The recognition of variants of serrated colorectal lesions that possessed relatively subtle but significant morphological differences from those of HPs and that could be associated with epithelial dysplasia and CRC led to the characterisation of sessile serrated lesions (SSLs) and traditional serrated adenomas (TSAs). These links were supported by the identification of genetic alterations that are commonly found in HPs, SSLs, TSAs, and CRC, e.g. BRAF and KRAS mutations. The 'serrated pathway' to CRC may progress faster than the traditional 'adenoma-carcinoma sequence', underlining the importance of identifying these lesions. The diagnostic histological criteria for SSLs have since been more clearly defined, in parallel with a drive to increase the recognition of these lesions at endoscopy. The existence of lesions showing overlapping morphological and molecular features with those of HPs, SSLs and TSAs has most recently been highlighted-including mucin-rich TSA, serrated tubulovillous adenoma, and those showing mixed histological features, e.g. comprising differing combinations of HP, SSL, and TSA. Morphological and molecular studies of this range of lesions are providing insights into the relationships of serrated colorectal lesions with each other and with CRC. This article provides an overview of the current understanding of serrated colorectal lesions, including a discussion of those with overlapping and mixed features.

Risk stratification for advanced colorectal neoplasia based on the findings of the index and first surveillance colonoscopies

Risk stratification by index colonoscopy is well established for first surveillance endoscopy, but whether the previous two colonoscopies affect the subsequent advanced neoplasias has not been established. Therefore, the subsequent risk based on the findings of the index and first surveillance colonoscopies were investigated. This retrospective, cohort study was conducted in two clinics and included participants who had undergone two or more colonoscopies after index colonoscopy. High-risk was defined as advanced adenoma (≥ 1 cm, or tubulovillous or villous histology, or high-grade dysplasia). Based on the findings of the index and first surveillance colonoscopies, patients were classified into four categories: category A (both colonoscopy findings were normal), category B (no high-risk findings both times), category C (one time high-risk finding), and category D (high-risk findings both times). The incidence of subsequent advanced neoplasia was examined in each category. A total of 13,426 subjects were included and surveyed during the study periods. The subjects in category D had the highest risk of advanced neoplasia (27.4%, n = 32/117). The subjects in category A had the lowest risk (4.0%, n = 225/5,583). The hazard ratio for advanced neoplasia of category D compared to category A was 9.90 (95% Confidence interval 6.82-14.35, P<0.001). Classification based on the findings of index and first surveillance colonoscopies more effectively stratifies the risk of subsequent advanced neoplasia, resulting in more proper allocation of colonoscopy resources after two consecutive colonoscopies.

A risk-stratified approach to colorectal cancer prevention and diagnosis

Population screening and endoscopic surveillance are used widely to prevent the development of and death from colorectal cancer (CRC). However, CRC remains a major cause of cancer mortality and the increasing burden of endoscopic investigations threatens to overwhelm some health services. This Perspective describes the rationale for and approach to improved risk stratification and decision-making for CRC prevention and diagnosis. Limitations of current approaches will be discussed using the UK as an example of the challenges faced by a particular health-care system, followed by discussion of novel risk biomarker utilization. We explore how risk stratification will be advantageous to current health-care providers and users, enabling more efficient use of limited colonoscopy resources. We discuss risk stratification in the setting of population screening as well as the surveillance of high-risk groups and investigation of symptomatic patients. We also address challenges in the development and validation of risk stratification tools and identify key research priorities.

Randomised comparison of postpolypectomy surveillance intervals following a two-round baseline colonoscopy: the Japan Polyp Study Workgroup

OBJECTIVE

To assess whether follow-up colonoscopy after polypectomy at 3 years only, or at 1 and 3 years would effectively detect advanced neoplasia (AN), including nonpolypoid colorectal neoplasms (NP-CRNs).

DESIGN

A prospective multicentre randomised controlled trial was conducted in 11 Japanese institutions. The enrolled participants underwent a two-round baseline colonoscopy (interval: 1 year) to remove all neoplastic lesions. Subsequently, they were randomly assigned to undergo follow-up colonoscopy at 1 and 3 years (2-examination group) or at 3 years only (1-examination group). The incidence of AN, defined as lesions with low-grade dysplasia ≥10 mm, high-grade dysplasia or invasive cancer, at follow-up colonoscopy was evaluated.

RESULTS

A total of 3926 patients were enrolled in this study. The mean age was 57.3 (range: 40-69) years, and 2440 (62%) were male. Of these, 2166 patients were assigned to two groups (2-examination: 1087, 1-examination: 1079). Overall, we detected 29 AN in 28 patients at follow-up colonoscopy in both groups. On per-protocol analysis (701 in 2-examination vs 763 in 1-examination group), the incidence of AN was similar between the two groups (1.7% vs 2.1%, p=0.599). The results of the non-inferiority test were significant (p=0.017 in per-protocol, p=0.001 in intention-to-treat analysis). NP-CRNs composed of dominantly of the detected AN (62%, 18/29), and most of them were classified into laterally spreading tumour non-granular type (83%, 15/18).

CONCLUSION

After a two-round baseline colonoscopy, follow-up colonoscopy at 3 years detected AN, including NP-CRNs, as effectively as follow-up colonoscopies performed after 1 and 3 years.

Lower Adenoma Miss Rate of Computer-Aided Detection-Assisted Colonoscopy vs Routine White-Light Colonoscopy in a Prospective Tandem Study

BACKGROUND AND AIMS

Up to 30% of adenomas might be missed during screening colonoscopy-these could be polyps that appear on-screen but are not recognized by endoscopists or polyps that are in locations that do not appear on the screen at all. Computer-aided detection (CADe) systems, based on deep learning, might reduce rates of missed adenomas by displaying visual alerts that identify precancerous polyps on the endoscopy monitor in real time. We compared adenoma miss rates of CADe colonoscopy vs routine white-light colonoscopy.

METHODS

We performed a prospective study of patients, 18-75 years old, referred for diagnostic, screening, or surveillance colonoscopies at a single endoscopy center of Sichuan Provincial People's Hospital from June 3, 2019 through September 24, 2019. Same day, tandem colonoscopies were performed for each participant by the same endoscopist. Patients were randomly assigned to groups that received either CADe colonoscopy (n=184) or routine colonoscopy (n=185) first, followed immediately by the other procedure. Endoscopists were blinded to the group each patient was assigned to until immediately before the start of each colonoscopy. Polyps that were missed by the CADe system but detected by endoscopists were classified as missed polyps. False polyps were those continuously traced by the CADe system but then determined not to be polyps by the endoscopists. The primary endpoint was adenoma miss rate, which was defined as the number of adenomas detected in the second-pass colonoscopy divided by the total number of adenomas detected in both passes.

RESULTS

The adenoma miss rate was significantly lower with CADe colonoscopy (13.89%; 95% CI, 8.24%-19.54%) than with routine colonoscopy (40.00%; 95% CI, 31.23%-48.77%, P<.0001). The polyp miss rate was significantly lower with CADe colonoscopy (12.98%; 95% CI, 9.08%-16.88%) than with routine colonoscopy (45.90%; 95% CI, 39.65%-52.15%) (P<.0001). Adenoma miss rates in ascending, transverse, and descending colon were significantly lower with CADe colonoscopy than with routine colonoscopy (ascending colon 6.67% vs 39.13%; P=.0095; transverse colon 16.33% vs 45.16%; P=.0065; and descending colon 12.50% vs 40.91%, P=.0364).

CONCLUSIONS

CADe colonoscopy reduced the overall miss rate of adenomas by endoscopists using white-light endoscopy. Routine use of CADe might reduce the incidence of interval colon cancers. chictr.org.cn study no: ChiCTR1900023086.

Cost savings in colonoscopy with artificial intelligence-aided polyp diagnosis: an add-on analysis of a clinical trial (with video)

BACKGROUND AND AIMS

Artificial intelligence (AI) is being implemented in colonoscopy practice, but no study has investigated whether AI is cost saving. We aimed to quantify the cost reduction using AI as an aid in the optical diagnosis of colorectal polyps.

METHODS

This study is an add-on analysis of a clinical trial that investigated the performance of AI for differentiating colorectal polyps (ie, neoplastic versus non-neoplastic). We included all patients with diminutive (≤5 mm) rectosigmoid polyps in the analyses. The average colonoscopy cost was compared for 2 scenarios: (1) a diagnose-and-leave strategy supported by the AI prediction (ie, diminutive rectosigmoid polyps were not removed when predicted as non-neoplastic), and (2) a resect-all-polyps strategy. Gross annual costs for colonoscopies were also calculated based on the number and reimbursement of colonoscopies conducted under public health insurances in 4 countries.

RESULTS

Overall, 207 patients with 250 diminutive rectosigmoid polyps (104 neoplastic, 144 non-neoplastic, and 2 indeterminate) were included. AI correctly differentiated neoplastic polyps with 93.3% sensitivity, 95.2% specificity, and 95.2% negative predictive value. Thus, 105 polyps were removed and 145 were left under the diagnose-and-leave strategy, which was estimated to reduce the average colonoscopy cost and the gross annual reimbursement for colonoscopies by 18.9% and US$149.2 million in Japan, 6.9% and US$12.3 million in England, 7.6% and US$1.1 million in Norway, and 10.9% and US$85.2 million in the United States, respectively, compared with the resect-all-polyps strategy.

CONCLUSIONS

The use of AI to enable the diagnose-and-leave strategy results in substantial cost reductions for colonoscopy.

CRC COVID: Colorectal cancer services during COVID-19 pandemic. Study protocol for service evaluation

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COVID-19 disrupted healthcare provision worldwide.

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This is a four-phase multi-centre service evaluation of colorectal cancer services.

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Conducted through a research collaborative in the UK, Ireland and the USA.

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The aim is to evaluate the impact of the COVID-19 pandemic on service provision.

Introduction

COVID-19 has had an impact on the provision of colorectal cancer care. The aim of the CRC COVID study is to describe the changes in colorectal cancer services in the UK and USA in response to the pandemic and to understand the long-term impact.

Methods and analysis

This study comprises 4 phases. Phase 1 is a survey of colorectal units that aims to evaluate adherences and deviations from the best practice guidelines during the COVID-19 pandemic. Phase 2 is a monthly prospective data collection of service provision that aims to determine the impact of the service modifications on the long-term cancer specific outcomes compared to the national standards. Phase 3 aims to predict costs attributable to the modifications of the CRC services and additional resources required to treat patients whose treatment has been affected by the pandemic. Phase 4 aims to compare the impact of COVID-19 on the NHS and USA model of healthcare in terms of service provision and cost, and to propose a standardised model of delivering colorectal cancer services for future outbreaks.

Ethics and dissemination

This study is a service evaluation and does not require HRA Approval or Ethical Approval in the UK. Local service evaluation registration is required for each participating centre. In the USA, Ethical Approval was granted by the Research and Development Committee. The results of this study will be disseminated to stakeholders, submitted for peer review publications, conference presentations and circulated via social media.

Registration details

Nil.

Colonoscopy and flexible sigmoidoscopy for follow-up of patients with left-sided diverticulitis

INTRODUCTION

The prevalence of diverticular disease has been increasing in the western world over the last few decades, causing a growing burden on health care systems. This study compared the uses of flexible sigmoidoscopy with colonoscopy as a follow-up investigation for patients diagnosed with acute left-sided diverticulitis and to evaluate the need for using either procedure.

MATERIALS AND METHODS

A retrospective study of 327 patients diagnosed with acute diverticulitis was carried out. Of this total, 240 patients with left-sided diverticulitis diagnosed via computed tomography were included. These patients were categorised into two equal groups: the first 120 patients underwent colonoscopy and the second 120 patients underwent flexible sigmoidoscopy.

RESULTS

All colonoscopes and flexible sigmoidoscopes confirmed the computed tomography diagnosis of sigmoid diverticular disease with no major new findings. All colonoscopes and flexible sigmoidoscopes were reported as having no complications, with nine colonoscopes reported as being difficult compared with only three flexible sigmoidoscopes. All biopsies were reported as no malignancy. Full bowel preparation was required in all colonoscopes, compared with no preparation required for flexible sigmoidoscopes.

CONCLUSIONS

There is no evidence to support the routine use of endoscopic evaluation after an episode of left-sided diverticulitis diagnosed on computed tomography if no worrying radiological findings have been reported. This study supports similar findings from other studies and therefore we disagree with The Royal College of Surgeons of England (Association of Coloproctology of Great Britain and Ireland recommendations) commissioning guide, which advocates routine surveillance of the colon.

Service evaluation of faecal immunochemical testing introduced for use in North East London for patients at low risk of colorectal cancer

AIMS

Colorectal cancer (CRC) is the fourth most common cancer in the UK. Following National Institute of Clinical Excellence (NICE) guidance for faecal immunochemical testing (FIT) (DG30), we introduced a service for the measurement of faecal haemoglobin (fHb) in symptomatic patients in line with the 2017 update of the NG12 guidance. The purpose of this study was to audit the use of FIT, focussing on the indication for request and referral for diagnostic tests as recommended in NICE guidance.

METHODS

Testing was rolled out after careful introduction with extensive education led by the local Cancer Alliance and reinforced by the laboratory. After 6 months, the outcomes of all patients tested were reviewed.

RESULTS

1203 samples were received, of which 894 (74.3%) were suitable for analysis. Of these, 482 (53.9%) actually met the criteria for FIT analysis stipulated in our patient pathway. Eight patients were diagnosed with CRC; fHb was detectable in all and was ≥200 µg/g in seven and <10 µg/g in one. 217 patients underwent gastrointestinal investigations, and the sensitivity and specificity of FIT for CRC were found to be 87.5% (95% CI 46.6% to 99.7%) and 52.6% (95% CI 45.6% to 59.6%), respectively. Patients with anaemia were more likely to have fHb ≥10 µg/g.

CONCLUSIONS

These findings suggest benefits from the introduction of FIT in terms of more efficient use of diagnostic investigations, while revealing initial problems relating to familiarity with a new test. This merits further intervention with education and awareness programmes for Primary Care and further audit.

Optimising bowel preparation before colonoscopy

A clean colon is required for a colonoscopy to be effective. Therefore, patients undergo a bowel preparation in advance of the procedure to clear the colon. Typically, this involves drinking 2 litres of polyethylene glycol or macrogol (PEG) solution, but dislike of the taste or having to drink such a large volume causes some patients not to adhere to this regimen. To address this, a PEG solution has been developed that requires patients to drink only 1 litre of bowel preparation in two flavours. The hope is this will increase patient adherence.

Colorectal Cancer Screening for the Serrated Pathway

Serrated polyps are classified into hyperplastic polyps, sessile serrated adenomas/polyps, and traditional serrated adenomas. Although all serrated polyps share characteristic colonic crypts serrations, distinguishing hyperplastic polyps from sessile serrated adenomas/polyps is challenging. Traditional serrated adenomas are cytologically dysplastic lesions; sessile serrated adenomas/polyps develop cytologic dysplasia as they progress to colorectal cancer. A flat and pale appearance of serrated polyps may make detection difficult. Endoscopic mucosal resection has higher rates of complete resection. Close surveillance is recommended for sessile serrated adenomas/polyps, sessile serrated adenomas/polyp with dysplasia, hyperplastic polyps ≥10 mm, and traditional serrated adenomas.

National census of UK endoscopy services in 2019

INTRODUCTION

The 2017 Joint Advisory Group on Gastrointestinal (GI) Endoscopy (JAG) census highlighted the pressure endoscopy services were under in meeting national targets and the factors behind this. In 2019, JAG conducted a further national census of endoscopy services to understand trends in activity, workforce and waiting time targets.

METHODS

In April 2019, the census was sent to all eligible JAG-registered services. Collated data were analysed through various statistical methods. A further comparative dataset was created using available submissions from the 2017 census matched to services in the current census.

RESULTS

There was a 68% response rate (322/471). There has been a 12%-15% increase in activity across all GI procedures with largest increases in bowel cancer screening. Fewer services are meeting waiting time targets compared with 2017, with endoscopist, nursing and physical capacity cited as the main reasons. Services are striving to improve capacity: 80% of services have an agreed business plan to meet capacity and the number using insourcing has increased from 13% to 20%. The workforce has increased, with endoscopist numbers increasing by 15%, nurses and allied health professionals by 14% and clerical staff by 30%.

CONCLUSIONS

The 2019 JAG census is the most recent and extensive survey of UK endoscopy services. There is a clear trend of increasing activity with fewer services able to meet national waiting time targets than 2 years ago. Services have increased their workforce and improved planning to stem the tide but there remains a continued pressure to deliver high quality, safe endoscopy. In light of the COVID-19 pandemic, JAG recognises that these pressures will be severely exacerbated and waiting time targets for accreditation will need adjustment and tolerance during the evolution and recovery from the pandemic.

Restarting gastrointestinal endoscopy in the deceleration and early recovery phases of COVID-19 pandemic: Guidance from the British Society of Gastroenterology

Many non-emergency clinical services were suspended during COVID-19 pandemic peak. It is essential to develop a plan for restarting services following the peak. It is equally important to protect patients and staff and to use resources and personal protective equipment (PPE) efficiently. The British Society of Gastroenterology Endoscopy Committee and Quality Improvement Programme has produced guidance on how a restart can be safely delivered. Key recommendations include the following: all patients should have need for endoscopy assessed by senior clinicians and prioritised according to criteria we have outlined; once the need for endoscopy is confirmed, patients should undergo telephone screening for symptoms using systematic questionnaires; all outpatients should undergo RT-PCR testing for COVID-19 virus 1-3 days prior to endoscopy; and PPE should be determined by patient risk stratification, the nature of the procedure and the results of testing. While this guidance is tailored to endoscopy services, it could be adapted for any interventional medical discipline.

Diagnostic ileocolonoscopy: getting the basics right

Proficient colonoscopy technique that optimises patient comfort while simultaneously enhancing the timely detection of pathology and subsequent therapy is an aspirational and achievable goal for every endoscopist. This article aims to provide strategies to improve colonoscopy quality for both endoscopists and patients.