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. Among participants indicating that they would attend flexible sigmoidoscopy screening if invited, randomisation (2:1) to the control (no further contact) or intervention (invited to once-only flexible sigmoidoscopy screening) group was performed centrally in blocks of 12, stratified by centre, general practice, and household type. Masking of intervention was infeasible. Primary outcomes were colorectal cancer incidence and mortality. The Kaplan-Meier method estimated cumulative incidence. Primary analyses estimated intention-to-treat hazard ratios (HRs) and risk differences, overall and stratified by subsite, sex, and age. The trial is registered with ISRCTN, number 28352761.
RESULTS: Among participants recruited between Nov 14, 1994, and March 30, 1999, 170 432 were eligible and 113 195 were randomly assigned to the control group and 57 237 were randomly assigned to the intervention group. 406 participants were excluded from analyses (268 in the control group and 138 in the intervention group), leaving 112 927 participants in the control group (55 336 [49%] men and 57 591 [51%] women) and 57 099 in the intervention group (27 966 [49%] men and 29 103 [51%] women). Of participants who were invited to be screened, 40 624 (71%) attended screening. Median follow-up was 21·3 years (IQR 18·0-22·2). In the invited-to-screening group, colorectal cancer incidence was reduced compared with the control group (1631 vs 4201 cases; cumulative incidence at 21 years was 3·18% [95% CI 3·03 to 3·34] vs 4·16% [4·04 to 4·29]; HR 0·76 [95% CI 0·72 to 0·81]) with 47 fewer cases per 100 000 person-years (95% CI -56 to -37). Colorectal cancer mortality was also reduced in the invited-to-screening group compared with the control group (502 vs 1329 deaths; cumulative incidence at 21 years was 0·97% [0·88 to 1·06] vs 1·33% [1·26 to 1·40]; HR 0·75 [0·67 to 0·83]) with 16 fewer deaths per 100 000 person-years (-21 to -11). Effects were particularly evident in the distal colorectum (726 incident cancer cases in the invited-to-screening group vs 2434 cases in the control group; HR 0·59 [0·54 to 0·64]; 47 fewer cases per 100 000 person-years [-54 to -41]; 196 cancer deaths in the invited-to-screening group vs 708 deaths in the control group; HR 0·55 [0·47 to 0·64]; 15 fewer deaths per 100 000 person-years [-19 to -12]) and not the proximal colon (871 incident cancer cases in the invited-to-screening group vs 1749 cases in the control group; HR 0·98 [0·91 to 1·07]; one fewer case per 100 000 person-years [-8 to 5]; 277 cancer deaths in the invited-to-screening group vs 547 deaths in the control group; HR 1·00 [0·86 to 1·15]; zero fewer deaths per 100 000 person-years [-4 to 4]). The HR for colorectal cancer incidence was lower in men (0·70 [0·65-0·76]) than women (0·86 [0·79 to 0·93]; pinteraction=0·0007) but there was no difference by age.
CONCLUSIONS: We show that once-only flexible sigmoidoscopy screening reduces colorectal cancer incidence and mortality for two decades and provide important data to inform colorectal cancer screening guidelines.
BACKGROUND: National Institute for Health and Care Research Health Technology Assessment Programme and the Medical Research Council.

UNASSIGNED: We conducted a comprehensive analysis to compare colonoscopy and sigmoidoscopy with standard care or fecal immunochemistry regarding colorectal cancer incidence and mortality risk.
UNASSIGNED: Until August 2023, literature from PubMed, Embase, Web of Science, and Cochrane was systematically reviewed. We examined the impact of colonoscopy or sigmoidoscopy versus standard care on colorectal cancer outcomes, including incidence, cancer-specific mortality, and overall mortality.
UNASSIGNED: Among 4,265 screened articles, data from seven randomized controlled trials (involving 663,319 participants) were analyzed. The intervention group (colonoscopy or sigmoidoscopy) consisted of 258,938 participants, while the control group received standard care or fecal immunochemical testing, totaling 404,381 participants, with both groups having average colorectal cancer risk, without confounders. Pooled analyses indicated a 20% reduction in colorectal cancer incidence (RR: 0.80, 95% CI: 0.77-0.83) and a 26% decrease in colorectal cancer mortality (RR: 0.74, 95% CI: 0.69-0.80) in the intervention group compared to standard care. All-cause mortality remained unchanged (RR: 1.03, 95% CI: 0.99-1.07). Subgroup analysis favored sigmoidoscopy in reducing colorectal cancer morbidity and mortality.
UNASSIGNED: This meta-analysis of randomized controlled trials underscores the effectiveness of colonoscopy and, notably, sigmoidoscopy in reducing colorectal cancer incidence and mortality among average-risk populations. In comparison to fecal immunochemical testing, both colonoscopy and sigmoidoscopy did not significantly impact colorectal cancer incidence and mortality in this population.
UNASSIGNED: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023460007.

As in any observational study, in a case-control study a primary concern is potential unmeasured confounders. Bias, due to unmeasured confounders, can result in a false discovery of an apparent treatment effect when there is none. Replication of an observational study, which tries to provide multiple analyses of the data where the biases affecting each analysis are thought to be different, is one way to strengthen the evidence from an observational study. Evidence factors allow for internal replication by testing a hypothesis using multiple comparisons in a way that the comparisons yield independent evidence and differ in the sources of potential bias. We construct evidence factors in a case-control study in which there are two types of cases, \"narrow\" cases which are thought to be potentially more affected by the exposure and \"marginal\" cases which are thought to have more heterogeneous causes. We develop and study an inference procedure for using such evidence factors and apply it to a study of the effect of sigmoidoscopy screening on colorectal cancer.

OBJECTIVE: Flexible sigmoidoscopy (FS) without analgesia or sedation can be unpleasant for patients, resulting in unsatisfactory examinations. Prior familiarization videos (FVs) and intra-procedural Entonox inhalation have shown inconsistent effects. This study investigated their effects on undesirable participant factors (anxiety, stress, discomfort, pain, satisfaction, later unpleasant recall of procedure, and vasovagal reactions) and clinical effectiveness (extent of bowel seen, lesions detected, and procedural/recovery times).
METHODS: This cluster-randomized single-center study evaluated 138 participants undergoing FS. There were 46 controls, 49 given access to FV, and 43 access to both FV and self-administered Entonox. Participant factors were measured by self-administered questionnaires, independent nurse assessments, and heart rate variability (HRV) metrics.
RESULTS: Questionnaires showed that the FV group was slightly more tense and upset before FS, but knowledge of Entonox availability reduced anxiety. Nonlinear HRV metrics confirmed reduced intra-procedural stress response in the FV/Entonox group compared with controls and FV alone (P < 0.05). Entonox availability allowed more bowel to be examined (P < 0.001) but increased procedure time (P < 0.05), while FV alone had no effect. FV/Entonox participants reported 1 month after FS less discomfort during the procedure. Other comparisons showed no significant differences between treatment groups, although one HRV metric showed some potential to predict vasovagal reactions.
CONCLUSIONS: Entonox availability significantly improved clinical effectiveness and caused a slight reduction in undesirable participant factors. The FV alone did not reduce undesirable participant factors or improve clinical effectiveness. Nonlinear HRV metrics recorded effects in agreement with stress reduction and may be useful for prediction of vasovagal events in future studies.

暂无摘要。

UNASSIGNED: Total colonoscopy is recommended if colorectal polyps are clinically suspected. This study aimed to investigate the performance status of pediatric colonoscopic polypectomy in Korea.
UNASSIGNED: We surveyed pediatric endoscopic specialists who perform colonoscopic polypectomy in Korea using a questionnaire of 13 questions on pediatric colonoscopic polypectomy performance status.
UNASSIGNED: The survey was conducted at 45 institutions, and 32 specialists (71.1%) responded. Among the respondents, 31.2% (10/32) said colonoscopy was performed in all age groups, while 12.5% (4/32) said sigmoidoscopy was performed in all age groups. Meanwhile, 56.2% (18/32) said that sigmoidoscopy was performed in young children, while colonoscopy was performed in older children. Among them, 38.9% (7/18) believe that 4-6 years were young, and 44.5% (8/18) believe that 7-9 years were young. Regarding surveillance examinations, 21.9% (7/32) said they would perform a surveillance colonoscopy or sigmoidoscopy in the future if less than five juvenile polyps were found in the colon. Meanwhile, if less than five adenomatous polyps were found in the colon, 93.8% (30/32) said they would perform surveillance colonoscopy or sigmoidoscopy in the future.
UNASSIGNED: More than half of the pediatric endoscopic specialists in Korea choose between a colonoscopy and sigmoidoscopy depending on the patient\'s age, contrary to the generally accepted recommendation of total colonoscopy if colorectal polyps are suspected in children and adolescents. In this survey, most pediatric endoscopists used the age range of 4-9 years as the reference age.

Convincing data in the literature demonstrate that screening reduces mortality in colorectal cancer. A recent study (NordICC) randomising nearly 85 000 healthy men and women drawn from population registries in Norway, Poland and Sweden to either colonoscopy or no screening reported 18 % reduction in incidence of colorectal cancer but no effect on mortality at 10-year follow-up. This finding is in contrast to previous randomised studies on sigmoidoscopy and cohort studies on coloscopy showing clear-cut effects on both colorectal cancer incidence and mortality. There could be several explanations for these discrepancies. In the NordICC study, only 42 % of the invited individuals performed a colonoscopy compared to 60-90 % in the other studies. Moreover, the follow-up time was only 10 years, and longer follow-up times will clarify the results better especially considering the fact that the number of colorectal cancer cases increases in the colonoscopy arms during the first year due to detection of presymptomatic cancers. Finally, adenoma detection rate varied a lot and nearly 30 % of the colonoscopists in the NordICC study had an adenoma detection rate below the recommended level of 25 %. Nonetheless, this is an important study that raises critical questions about colonscopy as a primary screening method for colorectal cancer.

Schistosomes infect over 200 million people worldwide, but few studies have characterized the effects of Schistosoma mansoni infection and effective treatment on the lower gastrointestinal mucosa. In this prospective cohort study, we compared the clinical findings on sigmoidoscopy and laboratory measures in Tanzanian adults with and without S. mansoni infection at baseline and 6 months after praziquantel treatment. Grading of the endoscopic findings was done using the Mayo Scoring System for Assessment of Ulcerative Colitis Activity. Schistosome infection was confirmed by stool microscopy and serum circulating anodic antigen (CAA). Baseline comparisons were performed in Stata using Fisher\'s exact and Wilcoxon rank-sum tests, and pre- and post-treatment comparisons using Wilcoxon matched-pairs signed-rank and McNemar\'s tests. We investigated the clinical characteristics of 48 individuals: 32 with and 16 without S. mansoni infection. Infected individuals had greater severity of sigmoid and rectal mucosal abnormalities and higher Mayo scores and serum eosinophils (all p < 0.05) than uninfected individuals at initial evaluation. At 6 months, 28 individuals completed repeat blood tests and sigmoidoscopy. Of these, 14 cleared their baseline infection (n = 7) or experienced a greater than 7-fold decrease in serum CAA (n = 7). Follow-up sigmoidoscopies revealed some improvements in sigmoid and rectal mucosal findings, although Mayo scores were not significantly lower. Both the median erythrocyte sedimentation rates (32.5→12.5 mm/hr) and percent of eosinophils (7.1→3.1%) decreased in this group from baseline to follow-up. S. mansoni infection was associated with mild-to-moderate lower gastrointestinal mucosal abnormalities that were grossly visible during sigmoidoscopy, and these improved partially 6 months after effective treatment with praziquantel. Additional studies, of longer duration and focused on both clinical and mucosal immunologic effects of S. mansoni, could provide additional insight.

Public health systems should guarantee universal access to health care services, including cancer screening. We assessed whether certain population subgroups were underrepresented among participants in colorectal cancer screening with sigmoidoscopy and faecal immunochemical testing (FIT). Between 2012 and 2019, about 140 000 individuals aged 50 to 74 years were randomly invited to once-only sigmoidoscopy or first round of FIT screening. Our study included 46 919 individuals invited to sigmoidoscopy and 70 019 to FIT between 2012 and 2017. We used logistic regression models to evaluate if demographic and socioeconomic factors and use of certain drugs were associated with participation. Twenty-four thousand one hundred and fifty-nine (51.5%) individuals attended sigmoidoscopy and 40 931 (58.5%) FIT screening. Male gender, young age, low education and income, being retired or unemployed, living alone, being an immigrant, long driving time to screening centre, and use of antidiabetic and psychotropic drugs were associated with low participation in both screening groups. Many of these factors also predicted low acceptance of colonoscopy after positive FIT. While male gender, young age and living alone were more strongly associated with nonparticipation in FIT than sigmoidoscopy, low education and income, being retired or immigrant and long driving time were more strongly associated with nonparticipation in sigmoidoscopy than FIT. In conclusion, participation was lower in sigmoidoscopy than FIT. Predictors of nonparticipation were similar between arms. However, low socioeconomic status, being an immigrant and long driving time affected participation more in sigmoidoscopy screening, suggesting that FIT may guarantee more equal access to screening services than sigmoidoscopy.

BACKGROUND: In Germany, statutory insured persons are entitled to a stool test (faecal immunochemical test (FIT)) or colonoscopy for colorectal cancer (CRC) screening, depending on age and sex, yet participation rates are rather low. Sigmoidoscopy is a currently not available screening measure that has a strong evidence base for incidence and mortality reduction. Due to its distinct characteristics, it might be preferred by some, who now reject colonoscopy. The objective of this study is to estimate the economic consequences of the additional offer of sigmoidoscopy for CRC screening in Germany compared with the present screening practice while considering the preferences of the general population.
METHODS: A decision-analytic modelling approach will be developed that compares the present CRC screening programme in Germany (FIT, colonoscopy) with a programme extended by sigmoidoscopy from a societal perspective. A decision tree and Markov model will be combined to assess both short-term and long-term effects, such as CRC and adenoma detection rates, the number of CRC cases, CRC mortality as well as complications. The incremental cost per quality-adjusted life year gained for each alternative will be calculated. The model will incorporate the general population\'s preferences based on a discrete choice experiment. Further, input parameters will be taken from the literature, the German cancer registry and health insurance claims data.
BACKGROUND: Ethical approval for the study was obtained from the Ethics Committee of Hannover Medical School (ID: 8671_BO_K_2019). The findings of the study will be published in peer-reviewed journals and presented at national and/or international conferences.
BACKGROUND: DRKS00019010.