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JAMA Network Open Feb 2024Randomized clinical screening trials have shown that sigmoidoscopy screening reduces colorectal cancer (CRC) incidence and mortality. Colonoscopy has largely replaced... (Randomized Controlled Trial)
Randomized Controlled Trial
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.
Topics: Female; Humans; Male; Colonoscopy; Computer Simulation; Early Detection of Cancer; Neoplasms; Sigmoidoscopy; Comparative Effectiveness Research
PubMed: 38421651
DOI: 10.1001/jamanetworkopen.2024.0007 -
British Medical Journal Aug 1980
Topics: Ambulatory Care; Humans; Proctoscopy; Sigmoidoscopy
PubMed: 7427364
DOI: No ID Found -
British Medical Journal Sep 1980
Topics: Anesthesia, General; Humans; Proctoscopy; Sigmoidoscopy
PubMed: 7437766
DOI: No ID Found -
The Cochrane Database of Systematic... Oct 2013Colorectal cancer is the third most frequent cancer in the world. As the sojourn time for this cancer is several years and a good prognosis is associated with early... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Colorectal cancer is the third most frequent cancer in the world. As the sojourn time for this cancer is several years and a good prognosis is associated with early stage diagnosis, screening has been implemented in a number of countries. Both screening with faecal occult blood test and flexible sigmoidoscopy have been shown to reduce mortality from colorectal cancer in randomised controlled trials. The comparative effectiveness of these tests on colorectal cancer mortality has, however, never been evaluated, and controversies exist over which test to choose.
OBJECTIVES
To compare the effectiveness of screening for colorectal cancer with flexible sigmoidoscopy to faecal occult blood testing.
SEARCH METHODS
We searched MEDLINE and EMBASE (November 16, 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (2012, Issue 11) and reference lists for eligible studies.
SELECTION CRITERIA
Randomised controlled trials comparing screening with flexible sigmoidoscopy or faecal occult blood testing to each other or to no screening. Only studies reporting mortality from colorectal cancer were included. Faecal occult blood testing had to be repeated (annually or biennially).
DATA COLLECTION AND ANALYSIS
Data retrieval and assessment of risk of bias were performed independently by two review authors. Standard meta-analyses using a random-effects model were conducted for flexible sigmoidoscopy and faecal occult blood testing (FOBT) separately and we calculated relative risks with 95% confidence intervals (CI). We used a Bayesian approach (a contrast-based network meta-analysis method) for indirect analyses and presented the results as posterior median relative risk with 95% credibility intervals. We assessed the quality of evidence using GRADE.
MAIN RESULTS
We identified nine studies comprising 338,467 individuals randomised to screening and 405,919 individuals to the control groups. Five studies compared flexible sigmoidoscopy to no screening and four studies compared repetitive guaiac-based FOBT (annually and biennially) to no screening. We did not consider that study risk of bias reduced our confidence in our results. We did not identify any studies comparing the two screening methods directly. When compared with no screening, colorectal cancer mortality was lower with flexible sigmoidoscopy (relative risk 0.72; 95% CI 0.65 to 0.79, high quality evidence) and FOBT (relative risk 0.86; 95% CI 0.80 to 0.92, high quality evidence). In the analyses based on indirect comparison of the two screening methods, the relative risk of dying from colorectal cancer was 0.85 (95% credibility interval 0.72 to 1.01, low quality evidence) for flexible sigmoidoscopy screening compared to FOBT. No complications occurred after the FOBT test itself, but 0.03% of participants suffered a major complication after follow-up. Among more than 60,000 flexible sigmoidoscopy screening procedures and almost 6000 work-up colonoscopies, a major complication was recorded in 0.08% of participants. Adverse event data should be interpreted with caution as the reporting of adverse effects was incomplete.
AUTHORS' CONCLUSIONS
There is high quality evidence that both flexible sigmoidoscopy and faecal occult blood testing reduce colorectal cancer mortality when applied as screening tools. There is low quality indirect evidence that screening with either approach reduces colorectal cancer deaths more than the other. Major complications associated with screening require validation from studies with more complete reporting of harms
Topics: Colonic Neoplasms; Colonoscopy; Guaiac; Humans; Indicators and Reagents; Occult Blood; Randomized Controlled Trials as Topic; Rectal Neoplasms; Sigmoidoscopy
PubMed: 24085634
DOI: 10.1002/14651858.CD009259.pub2 -
World Journal of Gastroenterology Dec 2014To conduct a systematic review and meta-analysis of published population-based randomized controlled trials (RCTs). (Meta-Analysis)
Meta-Analysis Review
AIM
To conduct a systematic review and meta-analysis of published population-based randomized controlled trials (RCTs).
METHODS
RCTs evaluating the difference in mortality and incidence of colorectal cancer (CRC) between a screening flexible sigmoidoscopy (FS) group and control group (not assigned to screening FS) with a minimum 5 years median follow-up were identified by a search of MEDLINE and EMBASE databases and the Cochrane Central Register for Controlled Trials through August 2013. Random effects model was used for meta-analysis.
RESULTS
Four RCTs with a total of 165659 patients in the FS group and 249707 patients in the control group were included in meta-analysis. Intention-to-treat analysis showed that there was a 22% risk reduction in total incidence of CRC (RR = 0.78, 95%CI: 0.74-0.83), 31% in distal CRC incidence (RR = 0.69, 95%CI: 0.63-0.75), and 9% in proximal CRC incidence (RR = 0.91, 95%CI: 0.83-0.99). Those who underwent screening FS were 18% less likely to be diagnosed with advanced CRC (OR = 0.82, 95%CI: 0.71-0.94). There was a 28% risk reduction in overall CRC mortality (RR = 0.72, 95%CI: 0.65-0.80) and 43% in distal CRC mortality (RR = 0.57, 95%CI: 0.45-0.72).
CONCLUSION
This meta-analysis suggests that screening FS can reduce the incidence of proximal and distal CRC and mortality from distal CRC along with reduction in diagnosis of advanced CRC.
Topics: Colorectal Neoplasms; Early Detection of Cancer; Equipment Design; Humans; Incidence; Odds Ratio; Predictive Value of Tests; Randomized Controlled Trials as Topic; Risk Factors; Sigmoidoscopes; Sigmoidoscopy
PubMed: 25561818
DOI: 10.3748/wjg.v20.i48.18466 -
British Medical Journal Aug 1980
Topics: Humans; Proctoscopy; Sigmoidoscopy
PubMed: 7427305
DOI: 10.1136/bmj.281.6237.435 -
Journal of Internal Medicine Apr 2021Colorectal cancer (CRC) is, besides breast, prostate, lung and skin cancers, the most common cancer worldwide and is suitable for screening. The incidence of CRC varies... (Review)
Review
Colorectal cancer (CRC) is, besides breast, prostate, lung and skin cancers, the most common cancer worldwide and is suitable for screening. The incidence of CRC varies considerably in different parts of the world: in well-developed countries, the incidence is between 30 and 70 per 100 000 inhabitants, whereas in less-developed countries such as sub-Saharan Africa, it is 10-20/100 000 inhabitants. Women have a lower incidence of CRC, which is usually one-third of total incidence. Several studies have shown that it is possible to decrease mortality from CRC with about 20%, which is evidenced through the data from countries with screening programmes. Though the method of choice to identify blood samples in faecal matter is under debate, the most feasible way is to perform colonoscopy. Other methods include more advanced faecal analyses, testing for mutations from CRC, sigmoidoscopy, CT colonoscopy or optical colonoscopy. Colonoscopy is in most countries not available in sufficient amount and has to be carried out with great accuracy; otherwise, lesions will be missed to identify, thus leading to complications. Gender is an issue in CRC screening, as women have about 20% fewer colorectal adenomas and CRCs, but they also have more right-sided lesions, which are more difficult to detect with tests for faecal blood since they create less blood in faeces. Thus, other strategies may have to be developed for women in order for screening to have the same effect. It is essential to introduce colorectal cancer screening in all countries together with other clinical pieces of advice such as information on smoking, obesity and exercise in order to reduce one of the most dangerous cancers.
Topics: Colonoscopy; Colorectal Neoplasms; Early Detection of Cancer; Female; Humans; Male; Mass Screening; Occult Blood; Sigmoidoscopy
PubMed: 32929813
DOI: 10.1111/joim.13171 -
Radiology Mar 2018Purpose To compare the acceptability of computed tomographic (CT) colonography and flexible sigmoidoscopy (FS) screening and the factors predicting CT colonographic... (Comparative Study)
Comparative Study Randomized Controlled Trial
Purpose To compare the acceptability of computed tomographic (CT) colonography and flexible sigmoidoscopy (FS) screening and the factors predicting CT colonographic screening participation, targeting participants in a randomized screening trial. Materials and Methods Eligible individuals aged 58 years (n = 1984) living in Turin, Italy, were randomly assigned to be invited to screening for colorectal cancer with FS or CT colonography. After individuals who had died or moved away (n = 28) were excluded, 264 of 976 (27.0%) underwent screening with FS and 298 of 980 (30.4%) underwent CT colonography. All attendees and a sample of CT colonography nonattendees (n = 299) were contacted for a telephone interview 3-6 months after invitation for screening, and screening experience and factors affecting participation were investigated. Odds ratios (ORs) were computed by means of multivariable logistic regression. Results For the telephone interviews, 239 of 264 (90.6%) FS attendees, 237 of 298 (79.5%) CT colonography attendees, and 182 of 299 (60.9%) CT colonography nonattendees responded. The percentage of attendees who would recommend the test to friends or relatives was 99.1% among FS and 93.3% among CT colonography attendees. Discomfort associated with bowel preparation was higher among CT colonography than FS attendees (OR, 2.77; 95% confidence interval [CI]: 1.47, 5.24). CT colonography nonattendees were less likely to be men (OR, 0.36; 95% CI: 0.18, 0.71), retired (OR, 0.31; 95% CI: 0.13, 0.75), to report regular physical activity (OR, 0.37; 95% CI: 0.20, 0.70), or to have read the information leaflet (OR, 0.18; 95% CI: 0.08, 0.41). They were more likely to mention screening-related anxiety (mild: OR, 6.30; 95% CI: 2.48, 15.97; moderate or severe: OR, 3.63; 95% CI: 1.87, 7.04), erroneous beliefs about screening (OR, 32.15; 95% CI: 6.26, 165.19), or having undergone a recent fecal occult blood test (OR, 13.69; 95% CI: 3.66, 51.29). Conclusion CT colonography and FS screening are well accepted, but further reducing the discomfort from bowel preparation may increase CT colonography screening acceptability. Negative attitudes, erroneous beliefs about screening, and organizational barriers are limiting screening uptake; all these factors are modifiable and therefore potentially susceptible to interventions. RSNA, 2017 Online supplemental material is available for this article.
Topics: Colonography, Computed Tomographic; Colorectal Neoplasms; Early Detection of Cancer; Female; Humans; Italy; Male; Middle Aged; No-Show Patients; Patient Acceptance of Health Care; Patient Participation; Patient Satisfaction; Self Report; Sigmoidoscopy
PubMed: 29040021
DOI: 10.1148/radiol.2017170228 -
Cancer Epidemiology Oct 2022High participation rates are important for a colorectal cancer (CRC) screening programme to be effective. Having a long travelling distance to screening centres may... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
High participation rates are important for a colorectal cancer (CRC) screening programme to be effective. Having a long travelling distance to screening centres may impede participation.
METHODS
We analysed the association between driving time from home address to screening centre and participation among individuals invited to screening with faecal immunochemical test (FIT) (n = 68,624) or sigmoidoscopy (n = 46,076) in a randomized trial in Norway in 2012-17. Two screening centres were involved. We fitted multiple logistic regression models, adjusted for demographic, socioeconomic and health characteristics, and reported odds ratios (OR) with 95% confidence intervals (CI).
RESULTS
Participation rates were 58.9 % (n = 40,445) for FIT and 51.9 % (n = 23,911) for sigmoidoscopy. In sigmoidoscopy, participation was 56.9 % and 47.9 % in those living < 20 and > 60 min by car from the screening centres, respectively. For each 10 min driving time increase, OR for participating in sigmoidoscopy screening was 0.93 (95 % CI 0.91-0.95). There was a significant difference between the two screening centres (p-value for heterogeneity <0.001). Participation in FIT screening were 61.2 % and 57.1 % in those with < 20 and > 60 min driving time, respectively, and the OR was 0.98 (95 % CI 0.96-0.99) for each 10 min increase (heterogeneity between screening methods, P-value <0.001). Among those with a positive FIT, compliance to colonoscopy was higher in those living < 20 compared to > 60 min from the centres (95.1 % vs. 92.9 %, respectively, OR 0.86; 95 % CI 0.77-0.93 for each 10 min increase).
CONCLUSIONS
Driving time to screening centre was a significant predictor of participation, mainly in sigmoidoscopy. There were local differences in the impact of driving time on participation. Driving time also affected compliance to colonoscopy after a positive FIT. When planning a CRC screening programme, one should consider offering people living far from screening sites special assistance to facilitate their participation.
Topics: Colonoscopy; Colorectal Neoplasms; Early Detection of Cancer; Hematologic Tests; Humans; Mass Screening; Occult Blood; Sigmoidoscopy
PubMed: 36057171
DOI: 10.1016/j.canep.2022.102244 -
Implementation Science : IS Sep 2011Appropriate screening may reduce the mortality and morbidity of colorectal, breast, and cervical cancers. However, effective implementation strategies are warranted if... (Review)
Review
BACKGROUND
Appropriate screening may reduce the mortality and morbidity of colorectal, breast, and cervical cancers. However, effective implementation strategies are warranted if the full benefits of screening are to be realized. As part of a larger agenda to create an implementation guideline, we conducted a systematic review to evaluate interventions designed to increase the rate of breast, cervical, and colorectal cancer (CRC) screening. The interventions considered were: client reminders, client incentives, mass media, small media, group education, one-on-one education, reduction in structural barriers, reduction in out-of-pocket costs, provider assessment and feedback interventions, and provider incentives. Our primary outcome, screening completion, was calculated as the overall median post-intervention absolute percentage point (PP) change in completed screening tests.
METHODS
Our first step was to conduct an iterative scoping review in the research area. This yielded three relevant high-quality systematic reviews. Serving as our evidentiary foundation, we conducted a formal update. Randomized controlled trials and cluster randomized controlled trials, published between 2004 and 2010, were searched in MEDLINE, EMBASE and PSYCHinfo.
RESULTS
The update yielded 66 studies new eligible studies with 74 comparisons. The new studies ranged considerably in quality. Client reminders, small media, and provider audit and feedback appear to be effective interventions to increase the uptake of screening for three cancers. One-on-one education and reduction of structural barriers also appears effective, but their roles with CRC and cervical screening, respectively, are less established. More study is required to assess client incentives, mass media, group education, reduction of out-of-pocket costs, and provider incentive interventions.
CONCLUSION
The new evidence generally aligns with the evidence and conclusions from the original systematic reviews. This review served as the evidentiary foundation for an implementation guideline. Poor reporting, lack of precision and consistency in defining operational elements, and insufficient consideration of context and differences among populations are areas for additional research.
Topics: Colonoscopy; Early Detection of Cancer; Health Promotion; Humans; Mammography; Mass Media; Occult Blood; Patient Education as Topic; Reminder Systems; Sigmoidoscopy; Vaginal Smears
PubMed: 21958556
DOI: 10.1186/1748-5908-6-111