Long-term effects of once-only flexible sigmoidoscopy screening on colorectal cancer incidence and mortality: 21-year follow-up of the UK Flexible Sigmoidoscopy Screening randomised controlled trial.

Background: Flexible sigmoidoscopy screening reduces colorectal cancer incidence and mortality; however, uncertainty exists about the duration of protection and differences by sex and age. We assessed effects of once-only flexible sigmoidoscopy screening after 21 years' follow-up.

Methods: The UK Flexible Sigmoidoscopy Screening Trial is a multicentre randomised controlled trial that recruited men and women aged 55-64 years from general practices serving 14 hospitals.

Effectiveness of Colonoscopy Screening vs Sigmoidoscopy Screening in Colorectal Cancer.

Importance: Randomized clinical screening trials have shown that sigmoidoscopy screening reduces colorectal cancer (CRC) incidence and mortality. Colonoscopy has largely replaced sigmoidoscopy for CRC screening, but long-term results from randomized trials on colonoscopy screening are still lacking.

Objective: To estimate the additional screening benefit of colonoscopy compared with sigmoidoscopy.

The impact of endoscopist performance and patient factors on distal adenoma detection and colorectal cancer incidence.

Background: High quality endoscopy is key for detecting and removing precursor lesions to colorectal cancer (CRC). Adenoma detection rates (ADRs) measure endoscopist performance. Improving other components of examinations could increase adenoma detection.

15-Year Benefits of Sigmoidoscopy Screening on Colorectal Cancer Incidence and Mortality : A Pooled Analysis of Randomized Trials.

Background: The effectiveness of screening for colorectal cancer (CRC) by sex and age in randomized trials is uncertain.

Objective: To evaluate the 15-year effect of sigmoidoscopy screening on CRC incidence and mortality.

Design: Pooled analysis of 4 large-scale randomized trials of sigmoidoscopy screening.

Colonoscopy surveillance following adenoma removal to reduce the risk of colorectal cancer: a retrospective cohort study.

Background: Colonoscopy surveillance is recommended for some patients post polypectomy. The 2002 UK surveillance guidelines classify post-polypectomy patients into low, intermediate and high risk, and recommend different strategies for each classification. Limited evidence supports these guidelines.

Post-polypectomy surveillance interval and advanced neoplasia detection rates: a multicenter, retrospective cohort study.

Background: Longer post-polypectomy surveillance intervals are associated with increased colorectal neoplasia detection at surveillance in some studies. We investigated this association to inform optimal surveillance intervals.

Methods: Patients who underwent colonoscopy and post-polypectomy surveillance at 17 UK hospitals were classified as low/high risk by baseline findings.

Adenoma characteristics associated with post-polypectomy proximal colon cancer incidence: a retrospective cohort study.

Background: Colorectal cancer (CRC) screening is less effective at reducing cancer incidence in the proximal colon compared to the distal colorectum. We aimed to identify adenoma characteristics associated with proximal colon cancer (PCC).

Methods: Endoscopy and pathology data for patients with ≥1 adenoma detected at baseline colonoscopy were obtained from 17 UK hospitals between 2001 and 2010.

Colorectal cancer risk following polypectomy in a multicentre, retrospective, cohort study: an evaluation of the 2020 UK post-polypectomy surveillance guidelines.

Objective: Colonoscopy surveillance aims to reduce colorectal cancer (CRC) incidence after polypectomy. The 2020 UK guidelines recommend surveillance at 3 years for 'high-risk' patients with ≥2 premalignant polyps (PMPs), of which ≥1 is 'advanced' (serrated polyp (or adenoma) ≥10 mm or with (high-grade) dysplasia); ≥5 PMPs; or ≥1 non-pedunculated polyp ≥20 mm; 'low-risk' patients without these findings are instead encouraged to participate in population-based CRC screening. We examined the appropriateness of these risk classification criteria and recommendations.

Higher Adenoma Detection Rates at Screening Associated With Lower Long-Term Colorectal Cancer Incidence and Mortality.

Background & Aims: Detection and removal of adenomas reduces colorectal cancer (CRC) risk. The impact of adenoma detection rates (ADRs) on long-term CRC incidence and mortality is unknown. We investigated this using data from the UK Flexible Sigmoidoscopy Screening Trial.

Heterogeneity in colorectal cancer incidence among people recommended 3-yearly surveillance post-polypectomy: a validation study.

Background:  Colonoscopy surveillance is recommended for patients at increased risk of colorectal cancer (CRC) following adenoma removal. Low-, intermediate-, and high-risk groups are defined by baseline adenoma characteristics. We previously examined intermediate-risk patients from hospital data and identified a higher-risk subgroup who benefited from surveillance and a lower-risk subgroup who may not require surveillance.

Long-term colorectal cancer incidence after adenoma removal and the effects of surveillance on incidence: a multicentre, retrospective, cohort study.

Objective: Postpolypectomy colonoscopy surveillance aims to prevent colorectal cancer (CRC). The 2002 UK surveillance guidelines define low-risk, intermediate-risk and high-risk groups, recommending different strategies for each. Evidence supporting the guidelines is limited.

Faecal immunochemical tests versus colonoscopy for post-polypectomy surveillance: an accuracy, acceptability and economic study.

Background: In the UK, patients with one or two adenomas, of which at least one is ≥ 10 mm in size, or three or four small adenomas, are deemed to be at intermediate risk of colorectal cancer (CRC) and referred for surveillance colonoscopy 3 years post polypectomy. However, colonoscopy is costly, can cause discomfort and carries a small risk of complications.

Objectives: To determine whether or not annual faecal immunochemical tests (FITs) are effective, acceptable and cost saving compared with colonoscopy surveillance for detecting CRC and advanced adenomas (AAs).

Whole-colon investigation vs. flexible sigmoidoscopy for suspected colorectal cancer based on presenting symptoms and signs: a multicentre cohort study.

Background: Patients with suspected colorectal cancer (CRC) usually undergo colonoscopy. Flexible sigmoidoscopy (FS) may be preferred if proximal cancer risk is low. We investigated which patients could undergo FS alone.

Faecal immunochemical tests (FIT) versus colonoscopy for surveillance after screening and polypectomy: a diagnostic accuracy and cost-effectiveness study.

Objective: The English Bowel Cancer Screening Programme (BCSP) recommends 3 yearly colonoscopy surveillance for patients at intermediate risk of colorectal cancer (CRC) postpolypectomy (those with three to four small adenomas or one ≥10 mm). We investigated whether faecal immunochemical tests (FITs) could reduce surveillance burden on patients and endoscopy services.

Design: Intermediate-risk patients (60-72 years) recommended 3 yearly surveillance were recruited within the BCSP (January 2012-December 2013).

Effect of once-only flexible sigmoidoscopy screening on the outcomes of subsequent faecal occult blood test screening.

Objective: To investigate the outcomes of biennial guaiac faecal occult blood test (gFOBT) screening after once-only flexible sigmoidoscopy (FS) screening.

Methods: Between 1994 and 1999, as part of the UK FS Screening Trial (UKFSST), adults aged 55-64 were randomly allocated to an intervention group (offered FS screening) or a control group (not contacted). From 2006, a subset of UKFSST participants (20,895/44,041 intervention group; 41,497/87,149 control group) were invited to biennial gFOBT screening by the English Bowel Cancer Screening Programme.

Number of Adenomas Removed and Colorectal Cancers Prevented in Randomized Trials of Flexible Sigmoidoscopy Screening.

Background & Aims: Screening for colorectal cancer (CRC) with sigmoidoscopy reduces CRC incidence by detecting and removing adenomas. The number needed to screen is a measure of screening efficiency, but is not directly associated with adenoma removal. We propose the following 2 new metrics for quantifying the relationship between adenoma removal and CRC prevented: number of adenomas needed to remove (NNR) and adenoma dwell time avoided (DTA).

Is whole-colon investigation by colonoscopy, computerised tomography colonography or barium enema necessary for all patients with colorectal cancer symptoms, and for which patients would flexible sigmoidoscopy suffice? A retrospective cohort study.

Background: For patients referred to hospital with suspected colorectal cancer (CRC), it is current standard clinical practice to conduct an examination of the whole colon and rectum. However, studies have shown that an examination of the distal colorectum using flexible sigmoidoscopy (FS) can be a safe and clinically effective investigation for some patients. These findings require validation in a multicentre study.

The clinical effectiveness of different surveillance strategies to prevent colorectal cancer in people with intermediate-grade colorectal adenomas: a retrospective cohort analysis, and psychological and economic evaluations.

Background: The UK guideline recommends 3-yearly surveillance for patients with intermediate-risk (IR) adenomas. No study has examined whether or not this group has heterogeneity in surveillance needs.

Objectives: To examine the effect of surveillance on colorectal cancer (CRC) incidence; assess heterogeneity in risk; and identify the optimum frequency of surveillance, the psychological impact of surveillance, and the cost-effectiveness of alternative follow-up strategies.

High test positivity and low positive predictive value for colorectal cancer of continued faecal occult blood test screening after negative colonoscopy.

Objectives The English Bowel Cancer Screening Programme offers biennial guaiac faecal occult blood test (gFOBT) screening to 60-74-year-olds. Participants with positive results are referred for follow-up, but many do not have significant findings. If they remain age eligible, these individuals are reinvited for gFOBT screening.

Adenoma surveillance and colorectal cancer incidence: a retrospective, multicentre, cohort study.

Background: Removal of adenomas reduces colorectal cancer incidence and mortality; however, the benefit of surveillance colonoscopy on colorectal cancer risk remains unclear. We examined heterogeneity in colorectal cancer incidence in intermediate-risk patients and the effect of surveillance on colorectal cancer incidence.

Methods: We did this retrospective, multicentre, cohort study using routine lower gastrointestinal endoscopy and pathology data from patients who, after baseline colonoscopy and polypectomy, were diagnosed with intermediate-risk adenomas mostly (>99%) between Jan 1, 1990, and Dec 31, 2010, at 17 hospitals in the UK.

Long term effects of once-only flexible sigmoidoscopy screening after 17 years of follow-up: the UK Flexible Sigmoidoscopy Screening randomised controlled trial.

Background: Colorectal cancer is the third most common cancer worldwide. Previous analyses have only reported follow-up after flexible sigmoidoscopy for a maximum of 12 years. We aimed to examine colorectal cancer incidence and mortality after a single flexible sigmoidoscopy screening and 17 years of follow-up.

Terminal digit preference biases polyp size measurements at endoscopy, computed tomographic colonography, and histopathology.

Background And Study Aims: Terminal digit preference bias for "pleasing" numbers has been described in many areas of medicine. The aim of this study was to determine whether endoscopists, radiologists, and pathologists exhibit such bias when measuring colorectal polyp diameters.

Methods: Colorectal polyp diameters measured at endoscopy, computed tomographic colonography (CTC), and histopathology were collated from a colorectal cancer screening program and two parallel multicenter randomized trials.