Strategies for Colorectal Cancer Screening Ladabaum, Uri; Dominitz, Jason A.; Kahi, Charles ...
Gastroenterology (New York, N.Y. 1943),
January 2020, 2020-01-00, 20200101, Letnik:
158, Številka:
2
Journal Article
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The incidence of colorectal cancer (CRC) is increasing worldwide. CRC has high mortality when detected at advanced stages, yet it is also highly preventable. Given the difficulties in implementing ...major lifestyle changes or widespread primary prevention strategies to decrease CRC risk, screening is the most powerful public health tool to reduce mortality. Screening methods are effective but have limitations. Furthermore, many screen-eligible people remain unscreened. We discuss established and emerging screening methods, and potential strategies to address current limitations in CRC screening. A quantum step in CRC prevention might come with the development of new screening strategies, but great gains can be made by deploying the available CRC screening modalities in ways that optimize outcomes while making judicious use of resources.
AbstractObjectiveTo estimate benefits and harms of different colorectal cancer screening strategies, stratified by (baseline) 15-year colorectal cancer risk.DesignMicrosimulation modelling study ...using MIcrosimulation SCreening ANalysis-Colon (MISCAN-Colon).SettingA parallel guideline committee (BMJ Rapid Recommendations) defined the time frame and screening interventions, including selection of outcome measures.PopulationNorwegian men and women aged 50-79 years with varying 15-year colorectal cancer risk (1-7%).ComparisonsFour screening strategies were compared with no screening: biennial or annual faecal immunochemical test (FIT) or single sigmoidoscopy or colonoscopy at 100% adherence.Main outcome measuresColorectal cancer mortality and incidence, burdens, and harms over 15 years of follow-up. The certainty of the evidence was assessed using the GRADE approach.ResultsOver 15 years of follow-up, screening individuals aged 50-79 at 3% risk of colorectal cancer with annual FIT or single colonoscopy reduced colorectal cancer mortality by 6 per 1000 individuals. Single sigmoidoscopy and biennial FIT reduced it by 5 per 1000 individuals. Colonoscopy, sigmoidoscopy, and annual FIT reduced colorectal cancer incidence by 10, 8, and 4 per 1000 individuals, respectively. The estimated incidence reduction for biennial FIT was 1 per 1000 individuals. Serious harms were estimated to be between 3 per 1000 (biennial FIT) and 5 per 1000 individuals (colonoscopy); harms increased with older age. The absolute benefits of screening increased with increasing colorectal cancer risk, while harms were less affected by baseline risk. Results were sensitive to the setting defined by the guideline panel. Because of uncertainty associated with modelling assumptions, we applied a GRADE rating of low certainty evidence to all estimates.ConclusionsOver a 15 year period, all screening strategies may reduce colorectal cancer mortality to a similar extent. Colonoscopy and sigmoidoscopy may also reduce colorectal cancer incidence, while FIT shows a smaller incidence reduction. Harms are rare and of similar magnitude for all screening strategies.
AbstractUpdate to this articleIn October 2022, three years after the initial publication of this guideline, the first trial of the effect of colonoscopy screening was published. The implications of ...this new evidence for the current recommendations were evaluated by the guideline panel in January 2023. The guideline panel judged that this new evidence did not alter the current recommendations, and therefore that an update of the following guideline was not needed (see table 2 for details).Clinical questionRecent 15-year updates of sigmoidoscopy screening trials provide new evidence on the effectiveness of colorectal cancer screening. Prompted by the new evidence, we asked: “Does colorectal cancer screening make an important difference to health outcomes in individuals initiating screening at age 50 to 79? And which screening option is best?”Current practiceNumerous guidelines recommend screening, but vary on recommended test, age and screening frequency. This guideline looks at the evidence and makes recommendations on screening for four screening options: faecal immunochemical test (FIT) every year, FIT every two years, a single sigmoidoscopy, or a single colonoscopy.RecommendationsThese recommendations apply to adults aged 50-79 years with no prior screening, no symptoms of colorectal cancer, and a life expectancy of at least 15 years. For individuals with an estimated 15-year colorectal cancer risk below 3%, we suggest no screening (weak recommendation). For individuals with an estimated 15-year risk above 3%, we suggest screening with one of the four screening options: FIT every year, FIT every two years, a single sigmoidoscopy, or a single colonoscopy (weak recommendation). With our guidance we publish the linked research, a graphic of the absolute harms and benefits, a clear description of how we reached our value judgments, and linked decision aids.How this guideline was createdA guideline panel including patients, clinicians, content experts and methodologists produced these recommendations using GRADE and in adherence with standards for trustworthy guidelines. A linked systematic review of colorectal cancer screening trials and microsimulation modelling were performed to inform the panel of 15-year screening benefits and harms. The panel also reviewed each screening option’s practical issues and burdens. Based on their own experience, the panel estimated the magnitude of benefit typical members of the population would value to opt for screening and used the benefit thresholds to inform their recommendations.The evidenceOverall there was substantial uncertainty (low certainty evidence) regarding the 15-year benefits, burdens, and harms of screening. Best estimates suggested that all four screening options resulted in similar colorectal cancer mortality reductions. FIT every two years may have little or no effect on cancer incidence over 15 years, while FIT every year, sigmoidoscopy, and colonoscopy may reduce cancer incidence, although for FIT the incidence reduction is small compared with sigmoidoscopy and colonoscopy. Screening related serious gastrointestinal and cardiovascular adverse events are rare. The magnitude of the benefits is dependent on the individual risk, while harms and burdens are less strongly associated with cancer risk.Understanding the recommendationBased on benefits, harms, and burdens of screening, the panel inferred that most informed individuals with a 15-year risk of colorectal cancer of 3% or higher are likely to choose screening, and most individuals with a risk of below 3% are likely to decline screening. Given varying values and preferences, optimal care will require shared decision making.
Multidisciplinary, evidence-based guidelines for quality assurance in colorectal cancer screening and diagnosis have been developed by experts in a project coordinated by the International Agency for ...Research on Cancer. The full guideline document covers the entire process of population-based screening. It consists of 10 chapters and over 250 recommendations, graded according to the strength of the recommendation and the supporting evidence. The 450-page guidelines and the extensive evidence base have been published by the European Commission. The chapter on quality assurance in endoscopy includes 50 graded recommendations. The content of the chapter is presented here to promote international discussion and collaboration by making the principles and standards recommended in the new EU Guidelines known to a wider professional and scientific community. Following these recommendations has the potential to enhance the control of colorectal cancer through improvement in the quality and effectiveness of endoscopy and other elements in the screening process, including multidisciplinary diagnosis and management of the disease.
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.
This is an analysis of the first 50 in-human uses of a novel digital rigid sigmoidoscope. The technology provides digital image capture, telemedicine capabilities, improved ergonomics, and the ...ability to biopsy under pneumorectum while maintaining the low cost of conventional rigid sigmoidoscopy. The primary outcome was adverse events, and the secondary outcome was diagnostic view.
Fifty patients underwent outpatient (n = 25) and surgical rectal assessment (n = 25), with a mean age of 60 years. This included 31 men and 19 women with 12 different clinical use indications. No adverse events were reported, and no defects were reported with the instrumentation. Satisfactory diagnoses were obtained in 48 (96%) of 50 uses, images were captured in 48 (96%) of 50 uses, and biopsies were successfully taken in 13 uses (26%). No adverse events were recorded. Independent reviewers of recorded videos agreed on the quality and diagnostic value of the images with a κ of 0.225 (95% CI, 0.144-0.305) when assessing whether the target pathology was adequately visualized.
The improved views afforded by digital rectoscopy facilitated a satisfactory clinical diagnosis in 96% of uses. The device was successfully deployed in the operating room and outpatients irrespective of bowel preparation method, where it has the potential to replace flexible sigmoidoscopy for specific use cases. The technology provides a high-quality image and video that can be securely recorded for documentation and medicolegal purposes with agreement between blinded users despite a lack of standardized training and heterogenous pathology. We perceive significant impact of this technology for the assessment of colorectal anastomoses, the office management of colitis, "watch and wait," and for diagnostic support in rectal cancer diagnosis. The technology has significant potential to facilitate proctoring and training, and it now requires prospective trials to validate its diagnostic accuracy against more costly flexible sigmoidoscopy systems.
Endoscopic screening reduces incidence and mortality of colorectal cancer (CRC) because precursor lesions, such as conventional adenomas or serrated polyps, are removed. Individuals with ...polypectomies are advised to undergo colonoscopy surveillance to prevent CRC. However, guidelines for surveillance intervals after diagnosis of a precursor lesion, particularly for individuals with serrated polyps, vary widely, and lack sufficient supporting evidence. Consequently, some high-risk patients do not receive enough surveillance and lower-risk subjects receive excessive surveillance.
We examined the association between findings from first endoscopy and CRC risk among 122,899 participants who underwent flexible sigmoidoscopy or colonoscopy in the Nurses’ Health Study 1 (1990–2012), Nurses’ Health Study 2 (1989–2013), or the Health Professionals Follow-up Study (1990–2012). Endoscopic findings were categorized as no polyp, conventional adenoma, or serrated polyp (hyperplastic polyp, traditional serrated adenoma, or sessile serrated adenoma, with or without cytological dysplasia). Conventional adenomas were classified as advanced (≥10 mm, high-grade dysplasia, or tubulovillous or villous histology) or nonadvanced, and serrated polyps were assigned to categories of large (≥10 mm) or small (<10 mm). We used a Cox proportional hazards regression model to calculate the hazard ratios (HRs) of CRC incidence, after adjusting for various potential risk factors.
After a median follow-up period of 10 years, we documented 491 incident cases of CRC: 51 occurred in 6161 participants with conventional adenomas, 24 in 5918 participants with serrated polyps, and 427 in 112,107 participants with no polyp. Compared with participants with no polyp detected during initial endoscopy, the multivariable HR for incident CRC in individuals with an advanced adenoma was 4.07 (95% confidence interval CI 2.89–5.72) and the HR for CRC in individuals with a large serrated polyp was 3.35 (95% CI 1.37–8.15). In contrast, there was no significant increase in risk of CRC in patients with nonadvanced adenomas (HR 1.21; 95% CI 0.68–2.16, P = .52) or small serrated polyps (HR 1.25; 95% CI 0.76–2.08; P = .38).
These findings provide support for guidelines that recommend repeat lower endoscopy within 3 years of a diagnosis of advanced adenoma and large serrated polyps. In contrast, patients with nonadvanced adenoma or small serrated polyps may not require more intensive surveillance than patients without polyps.
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Summary
Background
The value of lower gastrointestinal endoscopy (LGIE; colonoscopy or sigmoidoscopy) relates to its ability to detect clinically relevant findings, predominantly cancers, ...preneoplastic polyps or inflammatory bowel disease. There are concerns that many LGIEs are performed on low‐risk patients with limited benefit.
Aims
To determine the diagnostic outcomes of LGIE for common symptoms.
Methods
We performed a cross‐sectional study of diagnostic LGIE between March 2019 and February 2020 using the UK National Endoscopy Database. We used mixed‐effects logistic regression models, incorporating random (endoscopist) and fixed (symptoms, patient age, and sex) effects upon two dependent variables (large polyp ≥10 mm and cancer diagnosis). Adjusted positive predictive values (aPPVs) were calculated.
Results
We analysed 384,510 LGIEs; 33.2% were performed on patients aged under 50 and 53.6% on women. Regarding colonoscopies, the unadjusted PPV for cancer was 1.5% (95% CI: 1.4–1.5); higher for men than women (1.9% vs. 1.1%, p < 0.01). The PPV for large polyps was 3.2% (95% CI: 3.1–3.2). The highest colonoscopy cancer aPPVs were in the over 50s (1.9%) and in those with rectal bleeding (2.5%) or anaemia (2.1%). Cancer aPPVs for other symptoms were <1% despite representing 54.3% of activity. In patients under 50, aPPVs were 0.4% for cancer and 1.6% for large polyps. Results were similar for sigmoidoscopy.
Conclusions
Most colonoscopies were performed on patients with low‐risk symptoms, where cancer risk was similar to the general population. Cancer and large polyp yield was highest in elderly patients with rectal bleeding or anaemia, although still fell short of FIT‐based screening yields.
The findings assist in identifying patient groups that would benefit from endoscopic assessment: it is clear that blood is the key ‐ either overt blood, or occult bleeding presenting as anaemia, or in the context of screening, abnormal faecal occult blood test. Our study also identifies those who could be appropriately triaged towards less urgent or even no investigation.
After nearly 12 years of follow-up, the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial has shown that screening with flexible sigmoidoscopy reduces colorectal-cancer incidence by 21% ...and mortality by 26%.
Colorectal cancer is the second leading cause of cancer-related deaths in the United States.
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Colorectal-cancer mortality
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and incidence
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are reduced with screening by means of fecal occult-blood testing. Endoscopic screening with flexible sigmoidoscopy or colonoscopy is more sensitive than fecal testing for the detection of adenomatous polyps, the precursor lesions of colorectal cancer.
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Three European randomized trials of flexible sigmoidoscopy have been performed.
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In the United Kingdom, one-time screening with flexible sigmoidoscopy significantly reduced the incidence of colorectal cancer (by 23%) and associated mortality (by 31%).
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In Italy, an 18% reduction in incidence and a nonsignificant 22% . . .
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