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.

Design, Setting, and Participants

This comparative effectiveness simulation study pooled data on 358 204 men and women randomly assigned to sigmoidoscopy screening or usual care in 4 randomized sigmoidoscopy screening trials conducted in Norway, Italy, the US, and UK with inclusion periods in the years 1993 to 2001. The primary analysis of the study was conducted from January 19 to December 30, 2021.

Intervention

Invitation to endoscopic screening.

Main Outcomes and Measures

Primary outcomes were CRC incidence and mortality. Using pooled 15-year follow-up data, colonoscopy screening effectiveness was estimated assuming that the efficacy of colonoscopy in the proximal colon was similar to that observed in the distal colon in the sigmoidoscopy screening trials. The simulation model was validated using data from Norwegian participants in a colonoscopy screening trial.

Results

This analysis included 358 204 individuals (181 971 women [51%]) aged 55 to 64 years at inclusion with a median follow-up time ranging from 15 to 17 years. Compared with usual care, colonoscopy prevented an estimated 50 (95% CI, 42-58) CRC cases per 100 000 person-years, corresponding to 30% incidence reduction (rate ratio, 0.70 [95% CI, 0.66-0.75]), and prevented an estimated 15 (95% CI, 11-19) CRC deaths per 100 000 person-years, corresponding to 32% mortality reduction (rate ratio, 0.68 [95% CI, 0.61-0.76]). The additional benefit of colonoscopy screening compared with sigmoidoscopy was 12 (95% CI, 10-14) fewer CRC cases and 4 (95% CI, 3-5) fewer CRC deaths per 100 000 person-years, corresponding to percentage point reductions of 6.9 (95% CI, 6.0-7.9) for CRC incidence and 7.6 (95% CI, 5.7-9.6) for CRC mortality. The number needed to switch from sigmoidoscopy to colonoscopy screening was 560 (95% CI, 486-661) to prevent 1 CRC case and 1611 (95% CI, 1275-2188) to prevent 1 CRC death.

Conclusions and Relevance

The findings of this comparative effectiveness study assessing long-term follow-up after CRC screening suggest that there was an additional preventive effect on CRC incidence and mortality associated with colonoscopy screening compared with sigmoidoscopy screening, but the additional preventive effect was less than what was achieved by introducing sigmoidoscopy screening where no screening existed. The results probably represent the upper limit of what may be achieved with colonoscopy screening compared with sigmoidoscopy screening.

Risk Prediction of Metachronous Colorectal Cancer from Molecular Features of Adenomas: A Nested Case-Control Study

Current morphologic features defining advanced adenomas (size ≥10 mm, high-grade dysplasia or ≥25% villous component) cannot optimally distinguish individuals at high risk or low risk of metachronous colorectal cancer (me-CRC), which may result in suboptimal surveillance. Certain DNA copy-number alterations (CNAs) are associated with adenoma-to-carcinoma progression. We aimed to evaluate whether these molecular features can better predict an individual's risk of me-CRC than the morphologic advanced adenoma features.In this nested case-control study, 529 individuals with a single adenoma at first colonoscopy were selected from a Norwegian adenoma cohort. DNA copy-number profiles were determined, by low-coverage whole-genome sequencing. Prevalence of CNAs in advanced and non-advanced adenomas and its association (OR) with me-CRC was assessed. For the latter, cases (with me-CRC) were matched to controls (without me-CRC) on follow-up, age and sex.CNAs associated with adenoma-to-carcinoma progression were observed in 85/267 (32%) of advanced adenomas and in 27/262 (10%) of non-advanced adenomas. me-CRC was statistically significantly associated, also after adjustment for other variables, with age at baseline [OR, 1.14; 95% confidence interval CI), 1.03-1.26; P = 0.012], advanced adenomas (OR, 2.46; 95% CI, 1.50-4.01; P < 0.001) and with the presence of ≥3 DNA copy-number losses (OR, 1.90; 95% CI. 1.02-3.54; P = 0.043).Molecularly-defined high-risk adenomas were associated with me-CRC, but the association of advanced adenoma with me-CRC was stronger.

SIGNIFICANCE

Identifying new biomarkers may improve prediction of me-CRC for individuals with adenomas and optimize surveillance intervals to reduce risk of colorectal cancer and reduce oversurveillance of patients with low risk of colorectal cancer. Use of DNA CNAs alone does not improve prediction of me-CRC. Further research to improve risk classification is required.

Estimated Lifetime Gained With Cancer Screening Tests: A Meta-Analysis of Randomized Clinical Trials

Importance

Cancer screening tests are promoted to save life by increasing longevity, but it is unknown whether people will live longer with commonly used cancer screening tests.

Objective

To estimate lifetime gained with cancer screening.

Data Sources

A systematic review and meta-analysis was conducted of randomized clinical trials with more than 9 years of follow-up reporting all-cause mortality and estimated lifetime gained for 6 commonly used cancer screening tests, comparing screening with no screening. The analysis included the general population. MEDLINE and the Cochrane library databases were searched, and the last search was performed October 12, 2022.

Study Selection

Mammography screening for breast cancer; colonoscopy, sigmoidoscopy, or fecal occult blood testing (FOBT) for colorectal cancer; computed tomography screening for lung cancer in smokers and former smokers; or prostate-specific antigen testing for prostate cancer.

Data Extraction and Synthesis

Searches and selection criteria followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guideline. Data were independently extracted by a single observer, and pooled analysis of clinical trials was used for analyses.

Main Outcomes and Measures

Life-years gained by screening was calculated as the difference in observed lifetime in the screening vs the no screening groups and computed absolute lifetime gained in days with 95% CIs for each screening test from meta-analyses or single randomized clinical trials.

Results

In total, 2 111 958 individuals enrolled in randomized clinical trials comparing screening with no screening using 6 different tests were eligible. Median follow-up was 10 years for computed tomography, prostate-specific antigen testing, and colonoscopy; 13 years for mammography; and 15 years for sigmoidoscopy and FOBT. The only screening test with a significant lifetime gain was sigmoidoscopy (110 days; 95% CI, 0-274 days). There was no significant difference following mammography (0 days: 95% CI, -190 to 237 days), prostate cancer screening (37 days; 95% CI, -37 to 73 days), colonoscopy (37 days; 95% CI, -146 to 146 days), FOBT screening every year or every other year (0 days; 95% CI, -70.7 to 70.7 days), and lung cancer screening (107 days; 95% CI, -286 days to 430 days).

Conclusions and Relevance

The findings of this meta-analysis suggest that current evidence does not substantiate the claim that common cancer screening tests save lives by extending lifetime, except possibly for colorectal cancer screening with sigmoidoscopy.

A Comparison of Risk Classification Systems of Colorectal Adenomas: A Case-Cohort Study

BACKGROUND & AIMS

Because post-polypectomy surveillance uses a growing proportion of colonoscopy capacity, more targeted surveillance is warranted. We therefore compared surveillance burden and cancer detection using 3 different adenoma classification systems.

METHODS

In a case-cohort study among individuals who had adenomas removed between 1993 and 2007, we included 675 individuals with colorectal cancer (cases) diagnosed a median of 5.6 years after adenoma removal and 906 randomly selected individuals (subcohort). We compared colorectal cancer incidence among high- and low-risk individuals defined according to the traditional (high-risk: diameter ≥10 mm, high-grade dysplasia, villous growth pattern, or 3 or more adenomas), European Society of Gastrointestinal Endoscopy (ESGE) 2020 (high-risk: diameter ≥10 mm, high-grade dysplasia, or 5 or more adenomas), and novel (high-risk: diameter ≥20 mm or high-grade dysplasia) classification systems. For the different classification systems, we calculated the number of individuals recommended frequent surveillance colonoscopy and estimated number of delayed cancer diagnoses.

RESULTS

Four hundred and thirty individuals with adenomas (52.7%) were high risk based on the traditional classification, 369 (45.2%) were high risk based on the ESGE 2020 classification, and 220 (27.0%) were high risk based on the novel classification. Using the traditional, ESGE 2020, and novel classifications, the colorectal cancer incidences per 100,000 person-years were 479, 552, and 690 among high-risk individuals, and 123, 124, and 179 among low-risk individuals, respectively. Compared with the traditional classification, the number of individuals who needed frequent surveillance was reduced by 13.9% and 44.2%, respectively, and 1 (3.4%) and 7 (24.1%) cancer diagnoses were delayed using the ESGE 2020 and novel classifications.

CONCLUSIONS

Using the ESGE 2020 and novel risk classifications will substantially reduce resources needed for colonoscopy surveillance after adenoma removal.

A pilot study of implementation of endoscopic sleeve gastroplasty (ESG) in Norway

BACKGROUND AND AIM

Bariatric surgery is the most effective treatment for obesity but is invasive and associated with serious complications. Endoscopic sleeve gastroplasty (ESG) is a less invasive weight loss procedure to reduce the stomach volume by full-thickness sutures. ESG has been adopted in many countries, but implementation at Scandinavian centres has not yet been documented. We performed a clinical pilot trial at a Norwegian centre with the primary objective to assess the feasibility of the ESG procedure.

PATIENTS AND METHODS

We included the first 10 patients treated with ESG at a Norwegian centre in a single-arm pilot study. The eligibility criteria were either a body mass index (BMI) of 40-49.9 kg/m2, BMI 35-39.9 kg/m2 and at least one obesity-related comorbidity, or BMI 30-34.9 kg/m2 and type 2 diabetes. Patient follow-up resembled the scheme used for bariatric surgery at the center, including dietary plans and outpatient visits.

RESULTS

All procedures were technically successful except for one patient who had adhesions between the stomach and anterior abdominal wall, related to a prior hernia repair, resulting in less-than-intended stomach volume reduction. Mean total body weight loss (TBWL) after 26 and 52 weeks was 12.2% (95% CI 8.1-16.2) and 9.1% (95% CI 3.3 - 15.0). One patient experienced a minor suture-induced diaphragmatic injury, which was successfully managed conservatively.

CONCLUSIONS

This first Scandinavian clinical trial of ESG, documenting the implementation of the procedure at a Norwegian center, demonstrated acceptable feasibility and safety, with large variations in individual weight loss during the 52-week follow-up period.

Speedometer for withdrawal time monitoring during colonoscopy: a clinical implementation trial

OBJECTIVES

Meticulous inspection of the mucosa during colonoscopy, represents a lengthier withdrawal time, but has been shown to increase adenoma detection rate (ADR). We investigated if artificial intelligence-aided speed monitoring can improve suboptimal withdrawal time.

METHODS

We evaluated the implementation of a computer-aided speed monitoring device during colonoscopy at a large academic endoscopy center. After informed consent, patients ≥18 years undergoing colonoscopy between 5 March and 29 April 2021 were examined without the use of the speedometer, and with the speedometer between 29 April and 30 June 2021. All colonoscopies were recorded, and withdrawal time was assessed based on the recordings in a blinded fashion. We compared mean withdrawal time, percentage of withdrawal time ≥6 min, and ADR with and without the speedometer.

RESULTS

One hundred sixty-six patients in each group were eligible for analyses. Mean withdrawal time was 9 min and 6.6 s (95% CI: 8 min and 34.8 s to 9 min and 39 s) without the use of the speedometer, and 9 min and 9 s (95% CI: 8 min and 45 s to 9 min and 33.6 s) with the speedometer; difference 2.3 s (95% CI: -42.3-37.7, p = 0.91). The ADRs were 45.2% (95% CI: 37.6-52.8) without the speedometer as compared to 45.8% (95% CI: 38.2-53.4) with the speedometer (p = 0.91). The proportion of colonoscopies with withdrawal time ≥6 min without the speedometer was 85.5% (95% CI: 80.2-90.9) versus 86.7% (95% CI: 81.6-91.9) with the speedometer (p = 0.75).

CONCLUSIONS

Use of speed monitoring during withdrawal did not increase withdrawal time or ADR in colonoscopy.

CLINICALTRIALS.GOV IDENTIFIER

NCT04710251.

Risk of malignant lymphomas in patients with inflammatory bowel disease: a population-based cohort study

OBJECTIVE

To estimate the risk of non-Hodgkin's lymphoma (NHL) and Hodgkin's lymphoma (HL) in patients with inflammatory bowel disease (IBD).

DESIGN

We undertook a two-country population cohort study with all patients diagnosed with IBD in Norway and Sweden from 1987 and 1993 through 2015 and 2016, respectively, and analysed the risk of NHL and HL. In Sweden, we also analysed prescriptions of thiopurines and anti-tumour necrosis factor (TNF)-α therapy from 2005. We calculated standardised incidence ratios (SIRs) with 95% CIs using the general populations as reference.

RESULTS

Among 131 492 patients with IBD with a medium follow-up of 9.6 years, we identified 369 cases of NHL and 44 cases of HL. The SIR of NHL was 1.3 (95% CI 1.1 to 1.5) in ulcerative colitis and 1.4 (95% CI 1.2 to 1.7) in Crohn's disease. We found no compelling heterogeneity in analyses stratified by patient characteristics. We found a similar pattern and magnitude of excess risks for HL. At 10 years, cumulative incidence was 0.26% (95% CI 0.23% to 0.30%) and 0.06% (95% CI 0.04% to 0.08%) for NHL and HL, respectively. Higher excess risks were found among patients with NHL with concomitant primary sclerosing cholangitis (SIR 3.4; 95% CI 2.1 to 5.2) and in those prescribed thiopurines alone (SIR 2.8; 95% CI 1.4 to 5.7) or with anti-TNF-α agents (SIR 5.7; 95% CI 2.7 to 11.9).

CONCLUSION

Patients with IBD have a statistically significant increased risk of malignant lymphomas compared with the general population, but the absolute risk remains low.

Rates of repeated colonoscopies to clean the colon from low-risk and high-risk adenomas: results from the EPoS trials

OBJECTIVE

High-quality colonoscopy (adequate bowel preparation, whole-colon visualisation and removal of all neoplastic polyps) is a prerequisite to start polyp surveillance, and is ideally achieved in one colonoscopy. In a large multinational polyp surveillance trial, we aimed to investigate clinical practice variation in number of colonoscopies needed to enrol patients with low-risk and high-risk adenomas in polyp surveillance.

DESIGN

We retrieved data of all patients with low-risk adenomas (one or two tubular adenomas <10 mm with low-grade dysplasia) and high-risk adenomas (3-10 adenomas, ≥1 adenoma ≥10 mm, high-grade dysplasia or villous components) in the European Polyp Surveillance trials fulfilling certain logistic and methodologic criteria. We analysed variations in number of colonoscopies needed to achieve high-quality colonoscopy and enter polyp surveillance by endoscopy centre, and by endoscopists who enrolled ≥30 patients.

RESULTS

The study comprised 15 581 patients from 38 endoscopy centres in five European countries; 6794 patients had low-risk and 8787 had high-risk adenomas. 961 patients (6.2%, 95% CI 5.8% to 6.6%) underwent two or more colonoscopies before surveillance began; 101 (1.5%, 95% CI 1.2% to 1.8%) in the low-risk group and 860 (9.8%, 95% CI 9.2% to 10.4%) in the high-risk group. Main reasons were poor bowel preparation (21.3%) or incomplete colonoscopy/polypectomy (14.4%) or planned second procedure (27.8%). Need of repeat colonoscopy varied between study centres ranging from 0% to 11.8% in low-risk adenoma patients and from 0% to 63.9% in high-risk adenoma patients. On the second colonoscopy, the two most common reasons for a repeat (third) colonoscopy were piecemeal resection (26.5%) and unspecified reason (23.9%).

CONCLUSION

There is considerable practice variation in the number of colonoscopies performed to achieve complete polyp removal, indicating need for targeted quality improvement to reduce patient burden.

TRIAL REGISTRATION NUMBER

NCT02319928.

Impact of Artificial Intelligence on Colonoscopy Surveillance After Polyp Removal: A Pooled Analysis of Randomized Trials

BACKGROUND AND AIMS

Artificial intelligence (AI) tools aimed at improving polyp detection have been shown to increase the adenoma detection rate during colonoscopy. However, it is unknown how increased polyp detection rates by AI affect the burden of patient surveillance after polyp removal.

METHODS

We conducted a pooled analysis of 9 randomized controlled trials (5 in China, 2 in Italy, 1 in Japan, and 1 in the United States) comparing colonoscopy with or without AI detection aids. The primary outcome was the proportion of patients recommended to undergo intensive surveillance (ie, 3-year interval). We analyzed intervals for AI and non-AI colonoscopies for the U.S. and European recommendations separately. We estimated proportions by calculating relative risks using the Mantel-Haenszel method.

RESULTS

A total of 5796 patients (51% male, mean 53 years of age) were included; 2894 underwent AI-assisted colonoscopy and 2902 non-AI colonoscopy. When following U.S. guidelines, the proportion of patients recommended intensive surveillance increased from 8.4% (95% CI, 7.4%-9.5%) in the non-AI group to 11.3% (95% CI, 10.2%-12.6%) in the AI group (absolute difference, 2.9% [95% CI, 1.4%-4.4%]; risk ratio, 1.35 [95% CI, 1.16-1.57]). When following European guidelines, it increased from 6.1% (95% CI, 5.3%-7.0%) to 7.4% (95% CI, 6.5%-8.4%) (absolute difference, 1.3% [95% CI, 0.01%-2.6%]; risk ratio, 1.22 [95% CI, 1.01-1.47]).

CONCLUSIONS

The use of AI during colonoscopy increased the proportion of patients requiring intensive colonoscopy surveillance by approximately 35% in the United States and 20% in Europe (absolute increases of 2.9% and 1.3%, respectively). While this may contribute to improved cancer prevention, it significantly adds patient burden and healthcare costs.

Impact of time between faecal immunochemical tests in colorectal cancer screening on screening results: A natural experiment

Repeated rounds of faecal immunochemical testing (FIT) for occult blood is a common method for screening for colorectal cancer (CRC). However, the time interval between FIT rounds is not thoroughly investigated. In a CRC screening trial in South-Eastern Norway, individuals were invited for biennial FIT between 2012 and 2019. The positivity threshold was >15 mcg haemoglobin/g faeces (mcg/g). Due to organizational challenges, the interval between screening rounds randomly varied between 1.5 and 3.5 years, forming a natural experiment. We investigated the detection rate of CRC and advanced neoplasia (AN: CRC or advanced adenoma) at the subsequent round (FIT₂ ), according to the faecal haemoglobin concentration (f-Hb) at the initial screening round (FIT₁ ), and time between the two screening rounds. 18 522 individuals with negative FIT₁ who attended FIT₂ were included in this study. 245 AN were detected at FIT₂ , of which 34 were CRC. The CRC detection rate at FIT₂ for participants with FIT₁  = 0 mcg/g was 0.09% while it was 0.28% for participant with 0 > FIT₁  ≤ 15 mcg/g; odds ratio (OR) 3.22, 95% CI 1.49-6.95. For each 3 months' increment between FITs, the OR for detecting CRC was 1.33 (95% CI 0.98-1.79), while the OR was 1.13 (1.02-1.26) for AN. Individuals with FIT₁ -value of 0 mcg/g, had a lower AN detection rate compared with participants with 0 > FIT₁  ≤ 15 mcg/g, irrespective of time between tests. Although CRC and AN detection rates increase with increasing time interval between FITs, individuals with undetectable f-Hb at first screen have substantially lower risk of CRC at the next screening round compared with individuals with detectable f-Hb.

Reply to: Letter to the Editor regarding "Covid-19 transmission in fitness centers in Norway-a randomized trial"

In this correspondence we respond to critique of our randomized trial of Covid-19 transmission in fitness centers. The trial was performed in Norway during May and June 2020.

Abstract A004: Molecular adenoma features to predict metachronous colorectal cancer risk: A nested-case control study

Introduction: In colorectal cancer (CRC) surveillance, adenoma characteristics such as size, number of adenomas, dysplasia, and villous components, are used as indicators for risk of developing metachronous cancer and guide the surveillance interval. The current risk groups (e.g., advanced adenomas) cannot optimally distinguish high risk from low risk, which may result in suboptimal surveillance strategies. Specific DNA copy number aberrations are associated with risk of colorectal adenoma-to-carcinoma progression, but these aberrations are present in only a subset of advanced adenomas. Therefore, we hypothesize that specific DNA copy number aberrations may better predict the risk of CRC than advanced adenoma. Aim: To evaluate whether a molecularly-defined high-risk adenoma is a better risk factor for CRC than the presently used advanced adenoma. Materials and methods: DNA copy number profiles were determined, by means of low-coverage whole genome sequencing, on a series of 529 adenomas, selected from a Norwegian adenoma cohort. We retrieved detailed information on adenoma characteristics and whether adenoma patients were subsequently diagnosed with CRC or not. By univariate and multivariate regression analysis we estimated the odds ratio for association between the development of CRC and baseline presence of advanced adenoma versus presence of a molecularly-defined high-risk adenoma, respectively. Results: Molecular high-risk features were observed in 85/267 (32%) of advanced adenomas and in 27/262 (10%) of non-advanced adenomas. The odds ratio for developing metachronous CRC was 3.58 (p=2.84E-8) and 1.90 (p=0.012), when an advanced adenoma or molecular high-risk adenoma was detected at the baseline colonoscopy, respectively. In the multivariate regression analysis only advanced adenoma was as a significant risk factor for CRC. Conclusion: Molecularly-defined high-risk adenomas are associated with an increased risk of CRC. However, the advanced adenoma is a stronger predictor for risk of CRC.

Citation Format: Henriette C. Jodal, Eddymurphy U. Akwiwu, Leticia G. Leon, Margriet Lemmens, Pien Delis-van Diemen, Dagmar Klotz, Meike de Wit, Remond Fijneman, Monique van Leerdam, Evelien Dekker, Manon C. W. Spaander, Gerrit A. Meijer, Michael Bretthauer, Magnus Løberg, Veerle M. H. Coupé, Mette Kalager, Beatriz Carvalho. Molecular adenoma features to predict metachronous colorectal cancer risk: A nested-case control study [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr A004.

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.

SETTING

Norway, the United States, the United Kingdom, and Italy.

PARTICIPANTS

Women and men aged 55 to 64 years at enrollment.

INTERVENTION

Sigmoidoscopy screening.

MEASUREMENTS

Primary end points were cumulative incidence rate ratio (IRR) and mortality rate ratio (MRR) and rate differences after 15 years of follow-up comparing screening versus usual care in intention-to-treat analyses. Stratified analyses were done by sex, cancer site, and age at screening.

RESULTS

Analyses comprised 274 952 persons (50.7% women), 137 493 in the screening and 137 459 in the usual care group. Screening attendance was 58% to 84%. After 15 years, the rate difference for CRC incidence was 0.51 cases (95% CI, 0.40 to 0.63 cases) per 100 persons and the IRR was 0.79 (CI, 0.75 to 0.83). The rate difference for CRC mortality was 0.13 deaths (CI, 0.07 to 0.19 deaths) per 100 persons, and the MRR was 0.80 (CI, 0.72 to 0.88). Women had less benefit from screening than men for CRC incidence (IRR for women, 0.84 [CI, 0.77 to 0.91]; IRR for men, 0.75 [CI, 0.70 to 0.81]; P = 0.032 for difference) and mortality (MRR for women, 0.91 [CI, 0.77 to 1.17]; MRR for men, 0.73 [CI, 0.64 to 0.83]; P = 0.025 for difference). There was no statistically significant difference in screening effect between persons aged 55 to 59 years and those aged 60 to 64 years.

LIMITATION

Data from the U.K. trial were less granular because of privacy regulations.

CONCLUSION

This pooled analysis of all large randomized trials of sigmoidoscopy screening demonstrates a significant and sustained effect of sigmoidoscopy on CRC incidence and mortality for 15 years.

PRIMARY FUNDING SOURCE

Health Fund of South-East Norway.

Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death

BACKGROUND

Although colonoscopy is widely used as a screening test to detect colorectal cancer, its effect on the risks of colorectal cancer and related death is unclear.

METHODS

We performed a pragmatic, randomized trial involving presumptively healthy men and women 55 to 64 years of age drawn from population registries in Poland, Norway, Sweden, and the Netherlands between 2009 and 2014. The participants were randomly assigned in a 1:2 ratio either to receive an invitation to undergo a single screening colonoscopy (the invited group) or to receive no invitation or screening (the usual-care group). The primary end points were the risks of colorectal cancer and related death, and the secondary end point was death from any cause.

RESULTS

Follow-up data were available for 84,585 participants in Poland, Norway, and Sweden - 28,220 in the invited group, 11,843 of whom (42.0%) underwent screening, and 56,365 in the usual-care group. A total of 15 participants had major bleeding after polyp removal. No perforations or screening-related deaths occurred within 30 days after colonoscopy. During a median follow-up of 10 years, 259 cases of colorectal cancer were diagnosed in the invited group as compared with 622 cases in the usual-care group. In intention-to-screen analyses, the risk of colorectal cancer at 10 years was 0.98% in the invited group and 1.20% in the usual-care group, a risk reduction of 18% (risk ratio, 0.82; 95% confidence interval [CI], 0.70 to 0.93). The risk of death from colorectal cancer was 0.28% in the invited group and 0.31% in the usual-care group (risk ratio, 0.90; 95% CI, 0.64 to 1.16). The number needed to invite to undergo screening to prevent one case of colorectal cancer was 455 (95% CI, 270 to 1429). The risk of death from any cause was 11.03% in the invited group and 11.04% in the usual-care group (risk ratio, 0.99; 95% CI, 0.96 to 1.04).

CONCLUSIONS

In this randomized trial, the risk of colorectal cancer at 10 years was lower among participants who were invited to undergo screening colonoscopy than among those who were assigned to no screening. (Funded by the Research Council of Norway and others; NordICC ClinicalTrials.gov number, NCT00883792.).

Impact of artificial intelligence on colorectal polyp detection for early-career endoscopists: an international comparative study

BACKGROUND

Artificial intelligence (AI) for polyp detection is being introduced to colonoscopy, but there is uncertainty how this affects endoscopists' ability to detect polyps and neoplasms. We performed a video-based study to address whether AI improved the endoscopists' performance to detect polyps.

METHODS

We established a dataset of 200 colonoscopy videos (length 5 s; 100 without polyps and 100 with one polyp). About 33 early-career endoscopists (50-400 colonoscopies performed) from 10 European countries classified each video as either 'polyp present' or 'polyp not present'. The video assessment was performed twice with a four-week interval. The first assessment was performed without any AI tool, whereas the second was performed with an AI tool for polyp detection. The primary endpoint was early-career endoscopists' sensitivity to detect polyps. Gold standard for presence and histology of polyps were confirmed by two expert endoscopists and pathologists, respectively. McNemar's test was used for statistical significance.

RESULTS

There were 86 neoplastic and 14 non-neoplastic polyps (mean size 5.6 mm) in the 100 videos with polyps. Early-career endoscopists' sensitivity to detect polyps increased from 86.3% (95% confidence interval [CI]: 85.1-87.5%) to 91.7% (95%CI: 90.7-92.6%) with the AI aid (p < .0001). Their sensitivity to detect neoplastic polyps increased from 85.4% (95% CI: 84.0-86.7%) to 92.1% (95%CI: 91.1-93.1%) with the AI aid (p < .0001).

CONCLUSION

The polyp detection AI tool helped early-career endoscopists to increase their sensitivity to identify all polyps and neoplastic polyps during colonoscopy.

Complete polyp resection with cold snare versus hot snare polypectomy for polyps of 4-9 mm: a randomized controlled trial

BACKGROUND

Endoscopic screening with polypectomy reduces the incidence of colorectal cancer (CRC). Incomplete polyp removal may attenuate the effect of screening. This randomized trial compared cold snare polypectomy (CSP) with hot snare polypectomy (HSP) in terms of complete polyp resection.

METHODS

We included patients ≥ 40 years of age at eight hospitals in four countries who had at least one non-pedunculated polyp of 4-9 mm detected at colonoscopy. Patients were randomized 1:1 to CSP or HSP. Biopsies from the resection margins were obtained systematically after polypectomy in both groups. We hypothesized that CSP would be non-inferior to HSP, with a non-inferiority margin of 5 %. Logistic regression models were fitted to identify the factors explaining incomplete resection.

RESULTS

425 patients, with 601 polyps, randomized to either CSP or HSP were included in the analysis. Of 318 polyps removed by CSP and 283 polyps removed by HSP, 34 (10.7 %) and 21 (7.4 %) were incompletely resected, respectively, with an adjusted risk difference of 3.2 % (95 %CI -1.4 % to 7.8 %). There was no difference between the groups in terms of post-polypectomy bleeding, perforation, or abdominal pain. Independent risk factors for incomplete removal were serrated histology (odds ratio [OR] 3.96; 95 %CI 1.63 to 9.66) and hyperplastic histology (OR 2.52; 95 %CI 1.30 to 4.86) in adjusted analyses.

CONCLUSION

In this randomized trial, non-inferiority for CSP could not be demonstrated. Polyps with serrated histology are more prone to incomplete resection compared with adenomas. CSP can be used safely for small polyps in routine colonoscopy practice.

A progressive three-state model to estimate time to cancer: a likelihood-based approach

Background

To optimize colorectal cancer (CRC) screening and surveillance, information regarding the time-dependent risk of advanced adenomas (AA) to develop into CRC is crucial. However, since AA are removed after diagnosis, the time from AA to CRC cannot be observed in an ethically acceptable manner. We propose a statistical method to indirectly infer this time in a progressive three-state disease model using surveillance data.

Methods

Sixteen models were specified, with and without covariates. Parameters of the parametric time-to-event distributions from the adenoma-free state (AF) to AA and from AA to CRC were estimated simultaneously, by maximizing the likelihood function. Model performance was assessed via simulation. The methodology was applied to a random sample of 878 individuals from a Norwegian adenoma cohort.

Results

Estimates of the parameters of the time distributions are consistent and the 95% confidence intervals (CIs) have good coverage. For the Norwegian sample (AF: 78%, AA: 20%, CRC: 2%), a Weibull model for both transition times was selected as the final model based on information criteria. The mean time among those who have made the transition to CRC since AA onset within 50 years was estimated to be 4.80 years (95% CI: 0; 7.61). The 5-year and 10-year cumulative incidence of CRC from AA was 13.8% (95% CI: 7.8%;23.8%) and 15.4% (95% CI: 8.2%;34.0%), respectively.

Conclusions

The time-dependent risk from AA to CRC is crucial to explain differences in the outcomes of microsimulation models used for the optimization of CRC prevention. Our method allows for improving models by the inclusion of data-driven time distributions.

Supplementary Information

The online version contains supplementary material available at (10.1186/s12874-022-01645-2).

Real-Time Artificial Intelligence-Based Optical Diagnosis of Neoplastic Polyps during Colonoscopy

Real-Time AI-Based Diagnosis of Neoplastic PolypsColonoscopists diagnosed small colonic polyps as benign or malignant on the basis of their appearance. The results were compared in real time to see if CADx could distinguish among polyps requiring removal. For standard visual inspection versus CADx, we determined sensitivity for diagnosis (88.4% vs. 90.4%) and high confidence in assessment (74.2% vs. 92.6%).

Emergency hospital admissions, prognosis, and population mortality in Norway during the first wave of the Covid-19 epidemic

Background:

During the first wave of the Covid-19 epidemic, a national lockdown was established in Norway, and inhabitants were asked to contact healthcare only if absolutely necessary. We investigated hospital admissions and mortality due to non-Covid-19 disease during the lockdown compared to previous years.

Methods:

We compared the number of emergency admissions and in-hospital fatality for diagnoses probably unaffected (acute myocardial infarction, acute abdominal conditions, cerebrovascular diseases) and affected by the lockdown (infections, injuries) in the South-Eastern Health Region of Norway during weeks 12–22, 2020, compared to the mean of the same period in the years 2017–2019. We also compared population mortality March–May 2020, to the mean of the same period in years 2017–2019.

Results:

A total of 280,043 emergency admissions were observed; 20,911 admissions probably unaffected, and 30,905 admissions probably affected by the lockdown. Admissions due to diagnoses probably unaffected was reduced by 12% (95% confidence interval (CI) 9–15%), compared to 2017–2019. Admissions for diagnoses probably affected was reduced by 30% (95% CI 28–32%). There was a 34% reduction in in-hospital fatality due to acute myocardial infarction (95% CI 4–56%), 19% due to infections (95% CI 1–33%), and no change for the other diagnoses, compared to 2017–2019. The risk of in-hospital mortality to total mortality was lower for acute myocardial infarction (relative risk 0.85, 95% CI 0.73–0.99) and injuries (relative risk 0.83, 95% CI 0.70–0.98).

Conclusions:

Even though fewer patients were admitted to hospital, there was no increase in in-hospital fatality or population mortality, indicating that those who were most in need still received adequate care.

Risk of hepato-pancreato-biliary cancer is increased by primary sclerosing cholangitis in patients with inflammatory bowel disease: A population-based cohort study

BACKGROUND

There is continued uncertainty regarding the risks of hepato-pancreato-biliary cancers in patients with inflammatory bowel disease (IBD) with or without concomitant primary sclerosing cholangitis (PSC).

OBJECTIVE

To give updated estimates on risk of hepato-pancreato-biliary cancers in patients with IBD, including pancreatic cancer, hepatocellular carcinoma, gall bladder cancer, and intra - and extrahepatic cholangiocarcinoma.

METHODS

In a population-based cohort study, we included all patients diagnosed with IBD in Norway and Sweden from 1987 to 2016. The cohort comprised of 141,960 patients, identified through hospital databases and the National Patient Register. Participants were followed through linkage to national cancer, cause of death, and population registries. We calculated absolute risk and standardized incidence ratios (SIRs) of hepato-pancreato-biliary cancers by PSC and other clinical characteristics.

RESULTS

Of the 141,960 IBD patients, 3.2% were diagnosed with PSC. During a median follow-up of 10.0 years, we identified 443 biliary tract cancers (SIR 5.2, 95% confidence interval [CI] 4.8-5.7), 161 hepatocellular carcinomas (SIR 2.4, 95% CI 2.0-2.7) and 282 pancreatic cancers (SIR 1.3, 95% CI 1.2-1.5). The relative risks were considerably higher in PSC-IBD patients, with SIR of 140 (95% CI 123-159) for biliary tract, 38.6 (95% CI 29.2-50.0) for hepatocellular, and 9.0 (95% CI 6.3-12.6) for pancreatic cancer. The SIRs were still slightly increased in non-PSC-IBD patients, compared to the general population. For biliary tract cancer, the cumulative probability at 25 years was 15.6% in PSC-IBD patients, and 0.4% in non-PSC-IBD patients.

CONCLUSIONS

The dramatically increased risks of hepato-pancreato-biliary cancers in PSC-IBD patients support periodic surveillance for these malignancies. While much lower, the excess relative risks in non-PSC-IBD patients were not trivial compared to non-IBD related risk factors.

A novel intragastric balloon for treatment of obesity and type 2 diabetes. A two-center pilot trial

BACKGROUND AND AIMS

Obesity with type-2 diabetes is a global challenge. Lifestyle interventions have limited effect for most patients. Bariatric surgery is highly effective, but resource-demanding, invasive and associated with serious complications. Recently, a new intragastric balloon was introduced, not requiring endoscopy for placement or removal (Elipse™, Allurion Inc., Natick, MA). The balloon is swallowed in a capsule and filled with water once in the stomach. The balloon self-deflates after 4 months and is naturally excreted. The present trial investigated balloon feasibility, safety and efficacy in patients with obesity and type-2 diabetes.

PATIENTS AND METHODS

We treated 19 patients, with type-2 diabetes and body mass index (BMI) of 30.0-39.9 kg/m² at two Norwegian centers with the Elipse balloon. Patient follow-up during balloon treatment mimicked real-world clinical practice, including dietary plan and outpatient visits. The primary efficacy endpoints were total body weight loss (TBWL) and HbA1c at weeks 16 and 52.

RESULTS

All patients underwent balloon insertion uneventfully as out-patients. Mean TBWL and HbA1c reduction after 16 and 52 weeks of balloon insertion was 3.9% (95%CI 2.1-5.7) and 0.8% (95%CI 1.9-3.5); and 7 (95%CI 4-10), and 1 (95%CI -6 to 9) mmol/mol, respectively. Adverse events occurred in two patients (10.5%): one developed gastric outlet obstruction, managed by endoscopic balloon removal; the other excessive vomiting and dehydration, managed conservatively.

CONCLUSIONS

This first Scandinavian real-world clinical trial with a new minimally invasive intragastric balloon system demonstrated good feasibility, but did not confirm expected efficacy for weight loss and diabetes control.

Long-term colorectal cancer incidence and mortality after adenoma removal in women and men

BACKGROUND

Women and men with colorectal adenomas are at increased risk of colorectal cancer and colonoscopic surveillance is recommended. However, the long-term cancer risk remains unknown.

AIMS

To investigate colorectal cancer incidence and mortality after adenoma removal in women and men METHODS: We identified all individuals who had adenomas removed in Norway from 1993 to 2007, with follow-up through 2018. We calculated standardized incidence ratios (SIR) and incidence-based mortality ratios (SMR) with 95% confidence intervals (CI) for colorectal cancer in women and men using the female and male population for comparison. We defined high-risk adenomas as ≥2 adenomas, villous component, or high-grade dysplasia.

RESULTS

The cohort comprised 40 293 individuals. During median follow-up of 13.0 years, 1079 women (5.5%) and 866 men (4.2%) developed colorectal cancer; 328 women (1.7%) and 275 men (1.3%) died of colorectal cancer. Colorectal cancer incidence was more increased in women (SIR 1.64, 95% CI 1.54-1.74) than in men (SIR 1.12, 95% CI 1.05-1.19). Colorectal cancer mortality was increased in women (SMR 1.13, 95% CI 1.02-1.26) and reduced in men (SMR 0.79, 95% CI 0.71-0.89). Women with high-risk adenomas had an increased risk of colorectal cancer death (SMR 1.37, 95% CI 1.19-1.57); women with low-risk adenomas (SMR 0.90, 95% CI 0.76-1.07) and men with high-risk adenomas had a similar risk (SMR 0.89, 95% CI 0.76-1.04), while men with low-risk adenomas had reduced risk (SMR 0.70, 95% CI 0.59-0.84).

CONCLUSIONS

After adenoma removal, women had an increased risk of colorectal cancer death, while men had reduced risk, compared to the general female and male populations. Sex-specific surveillance recommendations after adenoma removal should be considered.

Characteristics of circulatory failure after out-of-hospital cardiac arrest: a prospective cohort study

Background

Circulatory failure after out-of-hospital cardiac arrest (OHCA) as part of the postcardiac arrest syndrome (PCAS) is believed to be caused by an initial myocardial depression that later subsides into a superimposed vasodilatation. However, the relative contribution of myocardial dysfunction and systemic inflammation has not been established. Our objective was to describe the macrocirculatory and microcirculatory failure in PCAS in more detail.

Methods

We included 42 comatose patients after OHCA where circulatory variables were invasively monitored from admission until day 5. We measured the development in cardiac power output (CPO), stroke work (SW), aortic elastance, microcirculatory metabolism, inflammatory and cardiac biomarkers and need for vasoactive medications. We used survival analysis and Cox regression to assess time to norepinephrine discontinuation and negative fluid balance, stratified by inflammatory and cardiac biomarkers.

Results

CPO, SW and oxygen delivery increased during the first 48 hours. Although the estimated afterload fell, the blood pressure was kept above 65 mmHg with a diminishing need for norepinephrine, indicating a gradually re-established macrocirculatory homoeostasis. Time to norepinephrine discontinuation was longer for patients with higher pro-brain natriuretic peptide concentration (HR 0.45, 95% CI 0.21 to 0.96), while inflammatory biomarkers and other cardiac biomarkers did not predict the duration of vasoactive pressure support. Markers of microcirculatory distress, such as lactate and venous-to-arterial carbon dioxide difference, were normalised within 24 hours.

Conclusion

The circulatory failure was initially characterised by reduced CPO and SW, however, microcirculatory and macrocirculatory homoeostasis was restored within 48 hours. We found that biomarkers indicating acute heart failure, and not inflammation, predicted longer circulatory support with norepinephrine. Taken together, this indicates an early and resolving, rather than a late and emerging vasodilatation.

Trial registration

NCT02648061.

The inflammatory response is related to circulatory failure after out-of-hospital cardiac arrest: A prospective cohort study

BACKGROUND

Whole body ischemia and reperfusion injury after cardiac arrest leads to the massive inflammation clinically manifested in the post-cardiac arrest syndrome. Previous studies on the inflammatory effect on circulatory failure after cardiac arrest have either investigated a selected patient group or a limited part of the inflammatory mechanisms. We examined the association between cardiac arrest characteristics and inflammatory biomarkers, and between inflammatory biomarkers and circulatory failure after cardiac arrest, in an unselected patient cohort.

METHODS

This was a prospective study of 50 consecutive patients with out-of-hospital cardiac arrest. Circulation was invasively monitored from admission until day five, whereas inflammatory biomarkers, i.e. complement activation, cytokines and endothelial injury, were measured daily. We identified predictors for an increased inflammatory response, and associations between the inflammatory response and circulatory failure.

RESULTS

We found a marked and broad inflammatory response in patients after cardiac arrest, which was associated with clinical outcome. Long time to return of spontaneous circulation and high lactate level at admission were associated with increased complement activation (TCC and C3bc), pro-inflammatory cytokines (IL-6, IL-8) and endothelial injury (syndecan-1) at admission. These biomarkers were in turn significantly associated with lower mean arterial blood pressure, lower cardiac output and lower systemic vascular resistance, and increased need of circulatory support in the initial phase. High levels of TCC and IL-6 at admission were significantly associated with increased 30-days mortality.

CONCLUSION

Inflammatory biomarkers, including complement activation, cytokines and endothelial injury, were associated with increased circulatory failure in the initial period after cardiac arrest.

Covid-19 transmission in fitness centers in Norway - a randomized trial

BACKGROUND

Closed fitness centers during the Covid-19 pandemic may negatively impact health and wellbeing. We assessed whether training at fitness centers increases the risk of SARS-CoV-2 virus infection.

METHODS

In a two-group parallel randomized controlled trial, fitness center members aged 18 to 64 without Covid-19-relevant comorbidities, were randomized to access to training at a fitness center or no-access. Fitness centers applied physical distancing (1 m for floor exercise, 2 m for high-intensity classes) and enhanced hand and surface hygiene. Primary outcomes were SARS-CoV-2 RNA status by polymerase chain reaction (PCR) after 14 days, hospital admission after 21 days. The secondary endpoint was SARS-CoV-2 antibody status after 1 month.

RESULTS

3764 individuals were randomized; 1896 to the training arm and 1868 to the no-training arm. In the training arm, 81.8% trained at least once, and 38.5% trained ≥six times. Of 3016 individuals who returned the SARS-CoV-2 RNA tests (80.5%), there was one positive test in the training arm, and none in the no-training arm (risk difference 0.053%; 95% CI - 0.050 to 0.156%; p = 0.32). Eleven individuals in the training arm (0.8% of tested) and 27 in the no-training arm (2.4% of tested) tested positive for SARS-CoV-2 antibodies (risk difference - 0.87%; 95%CI - 1.52% to - 0.23%; p = 0.001). No outpatient visits or hospital admissions due to Covid-19 occurred in either arm.

CONCLUSION

Provided good hygiene and physical distancing measures and low population prevalence of SARS-CoV-2 infection, there was no increased infection risk of SARS-CoV-2 in fitness centers in Oslo, Norway for individuals without Covid-19-relevant comorbidities.

TRIAL REGISTRATION

The trial was prospectively registered in ClinicalTrials.gov on May 13, 2020. Due to administrative issues it was first posted on the register website on May 29, 2020: NCT04406909 .

Mortality in Norway and Sweden during the COVID-19 pandemic

Background: Norway and Sweden are similar countries in terms of socioeconomics and health care. Norway implemented extensive COVID-19 measures, such as school closures and lockdowns, whereas Sweden did not. Aims: To compare mortality in Norway and Sweden, two similar countries with very different mitigation measures against COVID-19. Methods: Using real-world data from national registries, we compared all-cause and COVID-19-related mortality rates with 95% confidence intervals (CI) per 100,000 person-weeks and mortality rate ratios (MRR) comparing the five preceding years (2015–2019) with the pandemic year (2020) in Norway and Sweden. Results: In Norway, all-cause mortality was stable from 2015 to 2019 (mortality rate 14.6–15.1 per 100,000 person-weeks; mean mortality rate 14.9) and was lower in 2020 than from 2015 to 2019 (mortality rate 14.4; MRR 0.97; 95% CI 0.96–0.98). In Sweden, all-cause mortality was stable from 2015 to 2018 (mortality rate 17.0–17.8; mean mortality rate 17.1) and similar to that in 2020 (mortality rate 17.6), but lower in 2019 (mortality rate 16.2). Compared with the years 2015–2019, all-cause mortality in the pandemic year was 3% higher due to the lower rate in 2019 (MRR 1.03; 95% CI 1.02–1.04). Excess mortality was confined to people aged ⩾70 years in Sweden compared with previous years. The COVID-19-associated mortality rates per 100,000 person-weeks during the first wave of the pandemic were 0.3 in Norway and 2.9 in Sweden. Conclusions: All-cause mortality in 2020 decreased in Norway and increased in Sweden compared with previous years. The observed excess deaths in Sweden during the pandemic may, in part, be explained by mortality displacement due to the low all-cause mortality in the previous year.

Evidence and Precaution for Legal Health Interventions: Learning From the COVID-19 Pandemic

During the COVID-19 pandemic, the need for rapid legal interventions to protect public health has challenged standards of evidence generation and implementation. Investigators have generated high-quality evidence for drugs and vaccines at remarkable speed, but COVID-19 mitigation measures enforced by laws and regulations remain guided by the precautionary principle rather than by empirical evidence. This article discusses new concepts for embedded evidence generation for legal public health interventions in times of crisis.

Circulatory trajectories after out-of-hospital cardiac arrest: a prospective cohort study

BACKGROUND

Circulatory failure frequently occurs after out-of-hospital cardiac arrest (OHCA) and is part of post-cardiac arrest syndrome (PCAS). The aim of this study was to investigate circulatory disturbances in PCAS by assessing the circulatory trajectory during treatment in the intensive care unit (ICU).

METHODS

This was a prospective single-center observational cohort study of patients after OHCA. Circulation was continuously and invasively monitored from the time of admission through the following five days. Every hour, patients were classified into one of three predefined circulatory states, yielding a longitudinal sequence of states for each patient. We used sequence analysis to describe the overall circulatory development and to identify clusters of patients with similar circulatory trajectories. We used ordered logistic regression to identify predictors for cluster membership.

RESULTS

Among 71 patients admitted to the ICU after OHCA during the study period, 50 were included in the study. The overall circulatory development after OHCA was two-phased. Low cardiac output (CO) and high systemic vascular resistance (SVR) characterized the initial phase, whereas high CO and low SVR characterized the later phase. Most patients were stabilized with respect to circulatory state within 72 h after cardiac arrest. We identified four clusters of circulatory trajectories. Initial shockable cardiac rhythm was associated with a favorable circulatory trajectory, whereas low base excess at admission was associated with an unfavorable circulatory trajectory.

CONCLUSION

Circulatory failure after OHCA exhibits time-dependent characteristics. We identified four distinct circulatory trajectories and their characteristics. These findings may guide clinical support for circulatory failure after OHCA.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02648061.

Abstract 841: Risk of hepatobiliary & pancreatic cancer in inflammatory bowel disease

Background: The risk of hepatobiliary and pancreatic cancer in patients with inflammatory bowel disease (IBD) with or without concomitant primary sclerosing cholangitis (PSC) has not been reliably quantified in large, prospective studies with long-term follow-up.

Methods: We performed a population cohort study of all patients diagnosed with IBD in Norway and Sweden from 1987 to 2015. Participants were followed through linkage to national cancer, cause of death and population registers. We calculated standardized incidence ratios (SIR) with 95% confidence intervals (CIs) and absolute risk of hepatobiliary and pancreatic cancer by PSC status and other clinical characteristics.

Results: We identified 141,960 IBD patients, 4,548 (3.2%) of these with concomitant PSC. During a median follow-up time of 10.0 years, we identified 479 biliary tract cancers (SIR 5.2, 95% CI 4.7-5.7), 127 hepatocellular carcinomas (SIR 2.1, 95% CI 1.8-2.5) and 282 pancreatic cancers (SIR 1.3, 95% CI 1.2-1.5). The relative risks were considerably higher in patients with PSC, with SIRs of 142 (95% CI 125-160) for biliary tract, 27.7 (95% CI 19.4-38.5) for hepatocellular, and 9.0 (95% CI 6.3-12.6) for pancreatic cancer. For IBD patients without PSC, we found SIRs of 2.5 (95% CI 2.2-2.9), 1.5 (1.2-1.8), and 1.2 (1.1-1.4) for biliary tract cancer, hepatocellular carcinoma, and pancreatic cancer, respectively.

Conclusion: Patients with IBD experience a substantially increased risk of biliary tract cancer. Although the risk is largely confined to patients with concomitant PSC, non-PSC patients also confer a moderate excess risk.

Citation Format: Jingru Yu, Erle Refsum, Lise M. Helsingen, Trine Folseraas, Alexander Ploner, Paulina Wieszczy, Ishita Barua, Henriette C. Jodal, Espen Melum, Magnus Løberg, Johannes Blom, Michael Bretthauer, Hans-Olov Adami, Mette Kalager, Weimin Ye. Risk of hepatobiliary & pancreatic cancer in inflammatory bowel disease [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 841.

Estimation of overdiagnosis in colorectal cancer screening with sigmoidoscopy and faecal occult blood testing: comparison of simulation models

OBJECTIVE

To estimate overdiagnosis of colorectal cancer (CRC) for screening with sigmoidoscopy and faecal occult blood testing (FOBT).

DESIGN

Simulation study using data from randomised trials.

SETTING

Primary screening, UK, Norway PARTICIPANTS: 152 850 individuals from the Nottingham trial and 98 678 individuals from the Norwegian Colorectal Cancer Prevention (NORCCAP) trial.

INTERVENTION

CRC screening.

OUTCOME MEASURE

We estimated overdiagnosis using long-term data from two randomised trials: the Nottingham trial comparing FOBT screening every other year to no-screening, and the NORCCAP trial comparing once-only sigmoidoscopy screening to no-screening. To estimate the natural growth of adenomas to CRC, we used the following microsimulation models: (i) the Microsimulation Screening Analysis; (ii) the CRC Simulated Population model for Incidence and Natural history; (iii) the Simulation Model of Colorectal Cancer; (iv) a model derived by the German Cancer Research Center. We defined overdiagnosed cancers as the difference between the observed number of CRCs in the no-screening arm and the expected number of cancers in screening arm (sum of observed and prevented by adenoma removal). The amount of overdiagnosis is defined as the number of overdiagnosed cancers over the number of cancers observed in the no-screening arm.

RESULTS

Overdiagnosis estimates were highly dependent on model assumptions. For FOBT screening with 2354 cancers observed in control arm, four out of five models predicted overdiagnosis, range 2.0% (2400 cancers expected in screening) to 7.6% (2533 cancers expected in screening). For sigmoidoscopy screening with 452 cancers observed in control arm, all models predicted overdiagnosis, range 25.2% (566 cancers expected in screening) to 128.1% (1031 cancers expected in screening).

CONCLUSIONS

The amount of overdiagnosis estimated based on the microsimulation models varied substantially. Microsimulation models may not give reliable estimates of the preventive effect of adenoma removal, and should be used with caution to inform guidelines.

Incomplete endoscopic resection of colorectal polyps: a prospective quality assurance study

BACKGROUND

 Endoscopic screening with polypectomy has been shown to reduce colorectal cancer incidence in randomized trials. Incomplete polyp removal and subsequent development of post-colonoscopy cancers may attenuate the effect of screening. This study aimed to quantify the extent of incomplete polyp removal.

METHODS

 We included patients aged 50-75 years with nonpedunculated polyps ≥ 5 mm removed during colonoscopy at four hospitals in Norway. To evaluate completeness of polyp removal, biopsies from the resection margins were obtained after polypectomy. Logistic regression models were fitted to identify factors explaining incomplete resection.

RESULTS

 246 patients with 339 polyps underwent polypectomy between January 2015 and June 2017. A total of 12 polyps were excluded due to biopsy electrocautery damage, and 327 polyps in 246 patients (mean age 67 years [range 42-83]; 52 % male) were included in the analysis. Overall, 54 polyps (15.9 %) in 54 patients were incompletely resected. Histological diagnosis of the polyp (sessile serrated lesions vs. adenoma, odds ratio [OR] 10.9, 95 % confidence interval [CI] 3.9-30.1) and polyp location (proximal vs. distal colon, OR 2.8, 95 %CI 1.0-7.7) were independent risk factors for incomplete removal of polyps 5-19 mm. Board-certified endoscopists were not associated with lower rates of incomplete resection compared with trainees (14.0 % vs. 14.2 %), OR 1.0 (95 %CI 0.5-2.1).

CONCLUSION

Incomplete polyp resection was frequent after polypectomy in routine clinical practice. Serrated histology and proximal location were independent risk factors for incomplete resection. The performance of board-certified gastroenterologists was not superior to that of trainees.

Colonoscopist Performance and Colorectal Cancer Risk After Adenoma Removal to Stratify Surveillance: Two Nationwide Observational Studies

BACKGROUND AND AIMS

Colonoscopy surveillance after adenoma removal is an increasing burden in many countries. Surveillance recommendations consider characteristics of removed adenomas, but not colonoscopist performance. We investigated the impact of colonoscopist performance on colorectal cancer risk after adenoma removal.

METHODS

We compared colorectal cancer risk after removal of high-risk adenomas, low-risk adenomas, and after negative colonoscopy for all colonoscopies performed by colonoscopists with low vs high performance quality (adenoma detection rate <20% vs ≥20%) in the Polish screening program between 2000 and 2011, with follow-up until 2017. Findings were validated in the Austrian colonoscopy screening program.

RESULTS

A total of 173,288 Polish colonoscopies were included in the study. Of 262 colonoscopists, 160 (61.1%) were low performers, and 102 (38.9%) were high performers; 11.1% of individuals had low-risk and 6.6% had high-risk adenomas removed at screening; 82.2% had no adenomas. During 10 years of follow-up, 443 colorectal cancers were diagnosed. For low-risk adenoma individuals, colorectal cancer incidence was 0.55% (95% confidence interval [CI] 0.40-0.75) with low-performing colonoscopists vs 0.22% (95% CI 0.14-0.34) with high-performing colonoscopists (hazard ratio [HR] 2.35; 95% CI 1.31-4.21; P = .004). For individuals with high-risk adenomas, colorectal cancer incidence was 1.14% (95% CI 0.87-1.48) with low-performing colonoscopists vs 0.43% (95% CI 0.27-0.69) with high-performing colonoscopists (HR 2.69; 95% CI 1.62-4.47; P < .001). After negative colonoscopy, colorectal cancer incidence was 0.30% (95% CI 0.27-0.34) for individuals examined by low-performing colonoscopists, vs 0.15% (95% CI 0.11-0.20) for high-performing (HR 2.10; 95% CI 1.52-2.91; P < .001). The observed trends were reproduced in the Austrian validation cohort.

CONCLUSIONS

Our results suggest that endoscopist performance may be an important contributor in addition to polyp characteristics in determining colorectal cancer risk after colonoscopy screening.

Artificial intelligence for polyp detection during colonoscopy: a systematic review and meta-analysis

BACKGROUND

Artificial intelligence (AI)-based polyp detection systems are used during colonoscopy with the aim of increasing lesion detection and improving colonoscopy quality.

PATIENTS AND METHODS

We performed a systematic review and meta-analysis of prospective trials to determine the value of AI-based polyp detection systems for detection of polyps and colorectal cancer. We performed systematic searches in MEDLINE, EMBASE, and Cochrane CENTRAL. Independent reviewers screened studies and assessed eligibility, certainty of evidence, and risk of bias. We compared colonoscopy with and without AI by calculating relative and absolute risks and mean differences for detection of polyps, adenomas, and colorectal cancer.

RESULTS

Five randomized trials were eligible for analysis. Colonoscopy with AI increased adenoma detection rates (ADRs) and polyp detection rates (PDRs) compared to colonoscopy without AI (values given with 95 %CI). ADR with AI was 29.6 % (22.2 % - 37.0 %) versus 19.3 % (12.7 % - 25.9 %) without AI; relative risk (RR] 1.52 (1.31 - 1.77), with high certainty. PDR was 45.4 % (41.1 % - 49.8 %) with AI versus 30.6 % (26.5 % - 34.6 %) without AI; RR 1.48 (1.37 - 1.60), with high certainty. There was no difference in detection of advanced adenomas (mean advanced adenomas per colonoscopy 0.03 for each group, high certainty). Mean adenomas detected per colonoscopy was higher for small adenomas (≤ 5 mm) for AI versus non-AI (mean difference 0.15 [0.12 - 0.18]), but not for larger adenomas (> 5 - ≤ 10 mm, mean difference 0.03 [0.01 - 0.05]; > 10 mm, mean difference 0.01 [0.00 - 0.02]; high certainty). Data on cancer are unavailable.

CONCLUSIONS

AI-based polyp detection systems during colonoscopy increase detection of small nonadvanced adenomas and polyps, but not of advanced adenomas.

The COVID-19 pandemic in Norway and Sweden - threats, trust, and impact on daily life: a comparative survey

Background

Norway and Sweden have similar populations and health care systems, but different reactions to the COVID-19 pandemic. Norway closed educational institutions, and banned sports and cultural activities; Sweden kept most institutions and training facilities open. We aimed to compare peoples’ attitudes towards authorities and control measures, and perceived impact of the pandemic and implemented control measures on life in Norway and Sweden.

Methods

Anonymous web-based surveys for individuals age 15 or older distributed through Facebook using the snowball method, in Norway and Sweden from mid-March to mid-April, 2020. The survey contained questions about perceived threat of the pandemic, views on infection control measures, and impact on daily life. We performed descriptive analyses of the responses and compared the two countries.

Results

3508 individuals participated in the survey (Norway 3000; Sweden 508). 79% were women, the majority were 30–49 years (Norway 60%; Sweden 47%), and about 45% of the participants in both countries had more than 4 years of higher education.

Participants had high trust in the health services, but differed in the degree of trust in their government (High trust in Norway 17%; Sweden 37%). More Norwegians than Swedes agreed that school closure was a good measure (Norway 66%; Sweden 18%), that countries with open schools were irresponsible (Norway 65%; Sweden 23%), and that the threat from repercussions of the mitigation measures were large or very large (Norway 71%; Sweden 56%). Both countries had a high compliance with infection preventive measures (> 98%). Many lived a more sedentary life (Norway 69%; Sweden 50%) and ate more (Norway 44%; Sweden 33%) during the pandemic.

Conclusion

Sweden had more trust in the authorities, while Norwegians reported a more negative lifestyle during the pandemic. The level of trust in the health care system and self-reported compliance with preventive measures was high in both countries despite the differences in infection control measures.

Laparoscopy-assisted versus balloon enteroscopy-assisted ERCP after Roux-en-Y gastric bypass

BACKGROUND

Patients who have undergone Roux-en-Y gastric bypass (RYGB) are at increased risk of biliary disease necessitating endoscopic retrograde cholangiopancreatography (ERCP). The most widely used approaches to perform ERCP after RYGB are laparoscopy-assisted ERCP (LA-ERCP) and balloon enteroscopy-assisted ERCP (BEA-ERCP). There are few studies comparing these procedures. We aimed to compare the performance, benefits, and harms of LA-ERCP and BEA-ERCP in RYGB patients.

METHODS

We identified all RYGB patients who underwent ERCP at two tertiary care endoscopy centers in Oslo, Norway between May 2013 and December 2017. One center performed BEA-ERCP, the other LA-ERCP. Procedure success was defined as fulfillment of the therapeutic or diagnostic aim, according to the procedure description. Adverse events were classified according to the Clavien-Dindo grading system.

RESULTS

During the study period, 40 BEA-ERCP and 39 LA-ERCP procedures were performed in 68 patients. Procedure success rate was 72.5 % for BEA-ERCP and 87.2 % for LA-ERCP (P = 0.14). Adverse events occurred in 18 % of BEA-ERCP and 28 % of LA-ERCP (P = 0.23). Serious adverse events (Clavien-Dindo grade ≥ 3b) occurred in 2.5 % of BEA-ERCP and 7.7 % of LA-ERCP procedures (P = 0.36). Concomitant cholecystectomy was performed in 25 of the 39 LA-ERCP procedures. The median procedure times for LA-ERCP performed with and without concomitant cholecystectomy were 201 minutes and 140 minutes, respectively, and for BEA-ERCP was 125 minutes.

CONCLUSIONS

In experienced hands, both LA-ERCP and BEA-ERCP have high success rates after RYGB. The choice of approach should be individualized according to patient characteristics and available physician competence.

Implications of different guidelines for surveillance after serrated polyp resection in United States of America and Europe

INTRODUCTION

Because individuals with serrated polyps and adenomas are at increased risk of developing new polyps and colorectal cancer (CRC), surveillance after resection is justified. After adenoma resection, most international guidelines are consistent, but recommendations for surveillance after serrated polyp resection vary. The United States Multi-Society Taskforce on CRC (US-MSTF) base surveillance intervals on serrated polyp subtype (traditional serrated adenoma, sessile serrated polyp, hyperplastic polyps), while the European Society of Gastrointestinal Endoscopy (ESGE) guidelines do not take serrated polyp subtype into account. We evaluated the implications of this difference in a primary colonoscopy screening cohort.

METHODS

We included participants from a large colonoscopy screening trial. In a post-hoc simulation, assuming full protocol adherence, we determined the surveillance interval for each subject based on their polyp burden, using the most recent US-MSTF and ESGE guidelines.

RESULTS

We included 5323 participants, of whom 1228 had one or more serrated polyps. In 5201 of all participants (98 %; Cohen's kappa 0.90) and in 1106 of those with serrated polyps (90 %; Cohen's kappa 0.80), both guidelines recommended identical surveillance intervals. Recommendations for a 3-year surveillance interval were identical between the two guidelines. All 122 subjects with discordant recommendations would receive a follow-up colonoscopy after 10 years using ESGE guidance and after 5 years using US-MSTF guidance.

CONCLUSION

Despite the different criteria used to determine surveillance after serrated polyp resection, most individuals are recommended identical colonoscopy surveillance intervals whether following the ESGE or US-MSTF guidelines. This suggests that surveillance recommendations do not need to consider the serrated polyp subtype.

Continuous development of colorectal cancer screening programs

Colorectal cancer (CRC) screening programs are far from perfect. Many crucial questions remain, yet expensive CRC screening services are implemented throughout the world without a plan on how to evaluate and improve the service. The time is ripe for improving the design of CRC screening programs.