Endoscopic and surgical complications of work-up in screening for colorectal cancer

Should video laryngoscopy or direct laryngoscopy be used for adults undergoing endotracheal intubation in the pre-hospital setting? A critical appraisal of a systematic review

The safety and utility of endotracheal intubation by paramedics in the United Kingdom is a matter of debate. Considering the controversy surrounding the safety of paramedic-performed endotracheal intubation, any interventions that enhance patient safety should be evaluated for implementation based on solid evidence of their effectiveness. A systematic review performed by Hansel and colleagues (2022) sought to assess compare video laryngoscopes against direct laryngoscopes in clinical practice. This commentary aims to critically appraise the methods used within the review by Hansel et al (2022) and expand upon the findings in the context of clinical practice.

Colonoscopy-Related Adverse Events in Patients With Abnormal Stool-Based Tests: A Systematic Review of Literature and Meta-analysis of Outcomes

INTRODUCTION

Colorectal cancer (CRC) screening programs based on the fecal immunochemical test (FIT) and guaiac-based fecal occult blood (gFOBT) are associated with a substantial reduction in CRC incidence and mortality. We conducted a systematic review and comprehensive meta-analysis to evaluate colonoscopy-related adverse events in individuals with a positive FIT or gFOBT.

METHODS

A systematic and detailed search was run in January 2021, with the assistance of a medical librarian for studies reporting on colonoscopy-related adverse events as part of organized CRC screening programs. Meta-analysis was performed using the random-effects model, and the results were expressed for pooled proportions along with relevant 95% confidence intervals (CIs).

RESULTS

A total of 771,730 colonoscopies were performed in patients undergoing CRC screening using either gFOBT or FIT across 31 studies. The overall pooled incidence of severe adverse events in the entire patient cohort was 0.42% (CI 0.20-0.64); I2 = 38.76%. In patients with abnormal gFOBT, the incidence was 0.2% (CI 0.1-0.3); I2 = 24.6%, and in patients with a positive FIT, it was 0.4% (CI 0.2-0.7); I2 = 48.89%. The overall pooled incidence of perforation, bleeding, and death was 0.13% (CI 0.09-0.21); I2 = 22.84%, 0.3% (CI 0.2-0.4); I2 = 35.58%, and 0.01% (CI 0.00-0.01); I2 = 33.21%, respectively.

DISCUSSION

Our analysis shows that in colonoscopies performed after abnormal stool-based testing, the overall risk of severe adverse events, perforation, bleeding, and death is minimal.

IMPACT OF SCREENING ON SHORT-TERM MORTALITY AND MORBIDITY FOLLOWING TREATMENT FOR COLORECTAL CANCER

BACKGROUND AND AIMS

The aim of this study was to describe short-term changes in morbidity and mortality associated with the implementation of screening for colorectal cancer in Denmark.

MATERIALS AND METHODS

Prospective cohort study with inclusion of all patients aged 50-75 years treated for colorectal cancer between 1 March 2014 and 31 December 2015 in Denmark. Adjusted hazard ratios were calculated for 30 and 90 days mortality using Cox Regression. We made two adjusted models-a "basic" adjusted for screening status, sex, age, smoking, alcohol consumption, and cancer type and an "advanced" that also included body mass index and American society of Anesthesiologists score in analyses. Relative risks were calculated for postoperative surgical and medical complications.

RESULTS

In total, 5348 patients were included. In the "basic model," adjusted risk of 30 and 90 days total mortality was reduced in the screen-detected group (p < 0.01, HR = 0.43, CI = 0.24-0.76) and (p < 0.01, HR = 0.45, CI = 0.30-0.69). In the "advanced model," only 90 days total mortality was significantly reduced in the screen-detected group (p = 0.01, HR 0.59, CI = 0.39-0.90). No significant changes were found with regard to surgical and medical complications, respectively, (p = 0.05 (CI = 0.76-1.00) and p = 0.47(CI = 0.74-1.15)).

CONCLUSION

This nationwide study showed that screening for colorectal cancer was associated with a lower 90 days total mortality although no significant improvements were seen with regard to morbidity.

Screening for Colorectal Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Colorectal cancer (CRC) remains a significant cause of morbidity and mortality in the US.

OBJECTIVE

To systematically review the effectiveness, test accuracy, and harms of screening for CRC to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials for relevant studies published from January 1, 2015, to December 4, 2019; surveillance through March 26, 2021.

STUDY SELECTION

English-language studies conducted in asymptomatic populations at general risk of CRC.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently appraised the articles and extracted relevant study data from fair- or good-quality studies. Random-effects meta-analyses were conducted.

MAIN OUTCOMES AND MEASURES

Colorectal cancer incidence and mortality, test accuracy in detecting cancers or adenomas, and serious adverse events.

RESULTS

The review included 33 studies (n = 10 776 276) on the effectiveness of screening, 59 (n = 3 491 045) on the test performance of screening tests, and 131 (n = 26 987 366) on the harms of screening. In randomized clinical trials (4 trials, n = 458 002), intention to screen with 1- or 2-time flexible sigmoidoscopy vs no screening was associated with a decrease in CRC-specific mortality (incidence rate ratio, 0.74 [95% CI, 0.68-0.80]). Annual or biennial guaiac fecal occult blood test (gFOBT) vs no screening (5 trials, n = 419 966) was associated with a reduction of CRC-specific mortality after 2 to 9 rounds of screening (relative risk at 19.5 years, 0.91 [95% CI, 0.84-0.98]; relative risk at 30 years, 0.78 [95% CI, 0.65-0.93]). In observational studies, receipt of screening colonoscopy (2 studies, n = 436 927) or fecal immunochemical test (FIT) (1 study, n = 5.4 million) vs no screening was associated with lower risk of CRC incidence or mortality. Nine studies (n = 6497) evaluated the test accuracy of screening computed tomography (CT) colonography, 4 of which also reported the test accuracy of colonoscopy; pooled sensitivity to detect adenomas 6 mm or larger was similar between CT colonography with bowel prep (0.86) and colonoscopy (0.89). In pooled values, commonly evaluated FITs (14 studies, n = 45 403) (sensitivity, 0.74; specificity, 0.94) and stool DNA with FIT (4 studies, n = 12 424) (sensitivity, 0.93; specificity, 0.85) performed better than high-sensitivity gFOBT (2 studies, n = 3503) (sensitivity, 0.50-0.75; specificity, 0.96-0.98) to detect cancers. Serious harms of screening colonoscopy included perforations (3.1/10 000 procedures) and major bleeding (14.6/10 000 procedures). CT colonography may have harms resulting from low-dose ionizing radiation. It is unclear if detection of extracolonic findings on CT colonography is a net benefit or harm.

CONCLUSIONS AND RELEVANCE

There are several options to screen for colorectal cancer, each with a different level of evidence demonstrating its ability to reduce cancer mortality, its ability to detect cancer or precursor lesions, and its risk of harms.

Colorectal cancer screening with faecal testing, sigmoidoscopy or colonoscopy: a systematic review and network meta-analysis

OBJECTIVE

Evaluate effectiveness, harms and burdens of faecal blood testing, sigmoidoscopy and colonoscopy screening for colorectal cancer over 15 years.

DESIGN

We performed an update of a Cochrane systematic review, and performed network meta-analysis comparing randomised trials evaluating colorectal cancer screening with guaiac faecal occult blood test (gFOBT) (annual, biennial), faecal immunochemical test (FIT) (annual, biennial), sigmoidoscopy (once-only) or colonoscopy (once-only) in a healthy population, aged 50-79 years. We conducted subgroup analysis on sex. Follow-up >5 years was required for analysis of colorectal cancer incidence and mortality.

RESULTS

12 randomised trials proved eligible. Compared with no-screening, we found high certainty evidence for sigmoidoscopy screening slightly reducing colorectal cancer incidence (relative risk (RR) 0.76; 95% confidence interval (CI 0.70 to 0.83) and mortality (RR 0.74; 95% CI 0.69 to 0.80), while gFOBT screening had little or no difference on colorectal cancer incidence, but slightly reduced colorectal cancer mortality (annual: RR 0.69; 95% CI 0.56 to 0.86, biennial: RR 0.88; 95% CI 0.82 to 0.93). No screening test reduced mortality nor incidence by more than six per 1000 screened over 15 years. Sigmoidoscopy had a greater effect in men, for both colorectal cancer incidence (women: RR 0.86; 95% CI 0.81 to 0.92, men: RR 0.75, 95% CI 0.71 to 0.79), and mortality (women: RR 0.85; 95% CI 0.71 to 0.96, men: RR 0.67; 95% CI 0.61 to 0.75) (moderate certainty).

CONCLUSIONS

In a 15-year perspective, sigmoidoscopy reduces colorectal cancer incidence, while sigmoidoscopy, annual and biennial gFOBT all reduce colorectal cancer mortality. Sigmoidoscopy may reduce colorectal cancer incidence and mortality more in men than in women.

PROSPERO REGISTRATION NUMBER

CRD42018093401.

Colorectal Cancer Screening in Average Risk Populations: Evidence Summary

Introduction. The objectives of this systematic review were to evaluate the evidence for different CRC screening tests and to determine the most appropriate ages of initiation and cessation for CRC screening and the most appropriate screening intervals for selected CRC screening tests in people at average risk for CRC. Methods. Electronic databases were searched for studies that addressed the research objectives. Meta-analyses were conducted with clinically homogenous trials. A working group reviewed the evidence to develop conclusions. Results. Thirty RCTs and 29 observational studies were included. Flexible sigmoidoscopy (FS) prevented CRC and led to the largest reduction in CRC mortality with a smaller but significant reduction in CRC mortality with the use of guaiac fecal occult blood tests (gFOBTs). There was insufficient or low quality evidence to support the use of other screening tests, including colonoscopy, as well as changing the ages of initiation and cessation for CRC screening with gFOBTs in Ontario. Either annual or biennial screening using gFOBT reduces CRC-related mortality. Conclusion. The evidentiary base supports the use of FS or FOBT (either annual or biennial) to screen patients at average risk for CRC. This work will guide the development of the provincial CRC screening program.

Time to benefit for colorectal cancer screening: survival meta-analysis of flexible sigmoidoscopy trials

OBJECTIVE

To determine the time to benefit of using flexible sigmoidoscopy for colorectal cancer screening.

DESIGN

Survival meta-analysis.

DATA SOURCES

A Cochrane Collaboration systematic review published in 2013, Medline, and Cochrane Library databases.

ELIGIBILITY CRITERIA

Randomized controlled trials comparing screening flexible sigmoidoscopy with no screening. Trials with fewer than 100 flexible sigmoidoscopy screenings were excluded.

RESULTS

Four studies were eligible (total n = 459,814). They were similar for patients' age (50-74 years), length of follow-up (11.2-11.9 years), and relative risk for colorectal cancer related mortality (0.69-0.78 with flexible sigmoidoscopy screening). For every 1000 people screened at five and 10 years, 0.3 and 1.2 colorectal cancer related deaths, respectively, were prevented. It took 4.3 years (95% confidence interval 2.8 to 5.8) to observe an absolute risk reduction of 0.0002 (one colorectal cancer related death prevented for every 5000 flexible sigmoidoscopy screenings). It took 9.4 years (7.6 to 11.3) to observe an absolute risk reduction of 0.001 (one colorectal cancer related death prevented for every 1000 flexible sigmoidoscopy screenings).

CONCLUSION

Our findings suggest that screening flexible sigmoidoscopy is most appropriate for older adults with a life expectancy greater than approximately 10 years.

Time to benefit for colorectal cancer screening: survival meta-analysis of flexible sigmoidoscopy trials

OBJECTIVE

To determine the time to benefit of using flexible sigmoidoscopy for colorectal cancer screening.

DESIGN

Survival meta-analysis.

DATA SOURCES

A Cochrane Collaboration systematic review published in 2013, Medline, and Cochrane Library databases.

ELIGIBILITY CRITERIA

Randomized controlled trials comparing screening flexible sigmoidoscopy with no screening. Trials with fewer than 100 flexible sigmoidoscopy screenings were excluded.

RESULTS

Four studies were eligible (total n = 459,814). They were similar for patients' age (50-74 years), length of follow-up (11.2-11.9 years), and relative risk for colorectal cancer related mortality (0.69-0.78 with flexible sigmoidoscopy screening). For every 1000 people screened at five and 10 years, 0.3 and 1.2 colorectal cancer related deaths, respectively, were prevented. It took 4.3 years (95% confidence interval 2.8 to 5.8) to observe an absolute risk reduction of 0.0002 (one colorectal cancer related death prevented for every 5000 flexible sigmoidoscopy screenings). It took 9.4 years (7.6 to 11.3) to observe an absolute risk reduction of 0.001 (one colorectal cancer related death prevented for every 1000 flexible sigmoidoscopy screenings).

CONCLUSION

Our findings suggest that screening flexible sigmoidoscopy is most appropriate for older adults with a life expectancy greater than approximately 10 years.

Older adults' preferences for colorectal cancer-screening test attributes and test choice

BACKGROUND

Understanding which attributes of colorectal cancer (CRC) screening tests drive older adults' test preferences and choices may help improve decision making surrounding CRC screening in older adults.

MATERIALS AND METHODS

To explore older adults' preferences for CRC-screening test attributes and screening tests, we conducted a survey with a discrete choice experiment (DCE), a directly selected preferred attribute question, and an unlabeled screening test-choice question in 116 cognitively intact adults aged 70-90 years, without a history of CRC or inflammatory bowel disease. Each participant answered ten discrete choice questions presenting two hypothetical tests comprised of four attributes: testing procedure, mortality reduction, test frequency, and complications. DCE responses were used to estimate each participant's most important attribute and to simulate their preferred test among three existing CRC-screening tests. For each individual, we compared the DCE-derived attributes to directly selected attributes, and the DCE-derived preferred test to a directly selected unlabeled test.

RESULTS

Older adults do not overwhelmingly value any one CRC-screening test attribute or prefer one type of CRC-screening test over other tests. However, small absolute DCE-derived preferences for the testing procedure attribute and for sigmoidoscopy-equivalent screening tests were revealed. Neither general health, functional, nor cognitive health status were associated with either an individual's most important attribute or most preferred test choice. The DCE-derived most important attribute was associated with each participant's directly selected unlabeled test choice.

CONCLUSION

Older adults' preferences for CRC-screening tests are not easily predicted. Medical providers should actively explore older adults' preferences for CRC screening, so that they can order a screening test that is concordant with their patients' values. Effective interventions are needed to support complex decision making surrounding CRC screening in older adults.

Flexible sigmoidoscopy versus faecal occult blood testing for colorectal cancer screening in asymptomatic individuals

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

Harms of colonoscopy in a colorectal cancer screening programme with faecal occult blood test: a population-based cohort study

BACKGROUND AND AIMS

To assess the harms of colonoscopy in a real world colorectal cancer screening programme with faecal occult blood test.

METHODS

Retrospective cohort study of all colonoscopies performed in patients aged 50-74 for a positive guaiac-based faecal occult blood test between September 2003 and February 2010 within the screening programme in progress in Alsace (France). Adverse events were recorded through prospective voluntary reporting by gastroenterologists and retrospective postal surveys addressed to persons screened and their general practitioners.

RESULTS

Of 10,277 colonoscopies, 250 adverse events were recorded, 48 (4.7 ‰, 95% CI 3.4-6.0) of them being moderate or severe, mainly 10 (1.0 ‰, 95% CI 0.4-1.6) perforations and 31 (3.0 ‰, 95% CI 2.0-4.1) bleeding. 91.7% of moderate and severe adverse events were the result of a therapeutic procedure. Of 103 serious adverse events, eight (7.8%) were considered preventable. Gastroenterologists reported 52.2% of moderate and severe adverse events. A mild adverse event or an incident was reported in up to 97.0 ‰ (95% CI 83.2-110.7) colonoscopies.

CONCLUSION

The harms of colonoscopy were underestimated in all randomized controlled trials on colorectal cancer screening with faecal occult blood test. They are greater in a real world programme, estimated at 7.5 major and 100 minor adverse events per 1000 colonoscopies.

[Korean guidelines for colorectal cancer screening and polyp detection]

Colorectal cancer is the second most common cancer in males and the fourth most common in females in Korea. Since the most of colorectal cancer occur through the prolonged transformation of adenomas into carcinomas, early detection and removal of colorectal adenomas are one of the most effective methods to prevent colorectal cancer. Considering the increasing incidence of colorectal cancer and polyps in Korea, it is very important to establish Korean guideline for colorectal cancer screening and polyp detection. Korean Multi-Society Take Force developed the guidelines with evidence-based methods. Parts of the statements drawn by systematic reviews and meta-analyses. Herein we discussed the epidemiology of colorectal cancers and adenomas in Korea, optimal screening methods for colorectal cancer, and detection for adenomas including fecal occult blood tests, radiologic tests, and endoscopic examinations.

Korean guidelines for colorectal cancer screening and polyp detection

Now colorectal cancer is the second most common cancer in males and the fourth most common cancer in females in Korea. Since most of colorectal cancers occur after the prolonged transformation of adenomas into carcinomas, early detection and removal of colorectal adenomas are one of the most effective methods to prevent colorectal cancer. Considering the increasing incidence of colorectal cancer and polyps in Korea, it is very important to establish Korean guideline for colorectal cancer screening and polyp detection. The guideline was developed by the Korean Multi-Society Take Force and we tried to establish the guideline by evidence-based methods. Parts of the statements were draw by systematic reviews and meta-analyses. Herein we discussed epidemiology of colorectal cancers and adenomas in Korea and optimal methods for screening of colorectal cancer and detection of adenomas including fecal occult blood tests, radiologic tests, and endoscopic examinations.

Screening options and recommendations for colorectal cancer

Screening reduces the burden of disease from colorectal cancer through early detection of cancerous lesions and removal of precancerous polyps. The ideal colorectal cancer screening modality should be cost-effective, increase life-years gained, permit long intervals between tests with high patient compliance and low risk to the patient. Although no single colorectal cancer screening method is perfect, several options exist. Government agencies and medical societies have published screening recommendations with differing guidelines; yet, despite the lack of a consistent standard, it is clear that colorectal cancer screening is cost-effective. In this review, the authors address several options for screening, identify risks and benefits, and present methods to risk stratify patients. A thorough discussion with the patient about potential benefits and harms is critical before initiating any screening regimen.

Iatrogenic perforation at colonic imaging

AIM

Adequate colonic imaging is generally an invasive procedure with attendant risks, particularly perforation. Endoscopy, barium enema and computed tomographic colonography (CTC) are the main techniques for investigating patients with symptoms of, or screening for, colorectal cancer. The potential complications of these investigations have to be weighed against the benefits. This article reviews the literature on the incidence, presentation and management of iatrogenic colonic perforation at colonic imaging.

METHOD

A literature review of relevant studies was undertaken using PubMed, Cochrane library and personal archives of references. Manual cross-referencing was performed, and relevant references from selected articles were reviewed. Studies reporting complications of endoscopy, barium enema and CT colonography were included in this review.

RESULTS

Twenty-four studies were identified comprising 640,433 colonoscopies, with iatrogenic perforation recorded in 585 patients (0.06%). The reported perforation rate with double-contrast barium enema was between 0.02 and 0.24%. Serious complications with CTC were infrequent, though nine perforations were reported in a case series of 24,365 patients (0.036%) undergoing CTC.

CONCLUSION

Perforation remains an infrequent and almost certainly under-reported, complication of all colonic imaging modalities. Risk awareness, early diagnosis and active management of iatrogenic perforation minimizes an adverse outcome.

Complications of colonoscopy: magnitude and management

Although complications of colonoscopy are rare, they are potentially serious and life threatening. In addition, less serious adverse events may occur frequently and may have an impact on a patient's willingness to undergo future procedures. This article reviews the magnitude of and risk factors for major and minor colonoscopy complications, discusses management of complications, and suggests ways to design quality improvement programs to reduce the risk of complications.

The impact of national guidelines on the waiting list for colonoscopy: a quantitative clinical audit

OBJECTIVE

To assess the compliance of the surveillance colonoscopy waiting list with ACPGBI/BSG guidelines for colonoscopy follow-up and to measure the impact of adjusting referrals to be inline with the guidelines.

DESIGN AND SETTING

This is a quantitative five-stage clinical audit cycle involving a large patient cohort from the Kent and Medway Cancer Network, which includes seven hospitals across four NHS Hospital Trusts and an estimated population of 1.8 million.

PARTICIPANTS

3020 patients were waiting for a surveillance colonoscopy. Their notes were reviewed and the indications for colonoscopy were compared with the ACPGBI/BSG 2002 guidelines.

INTERVENTIONS

Those patients whose referral to the surveillance colonoscopy waiting list was not found to be compliant were adjusted to be inline with the guidelines.

MAIN OUTCOME MEASURES

The impact of adjusting the surveillance colonoscopy waiting list on the diagnostic colonoscopy service was assessed by measuring the average waiting times for a colonoscopy before and after the intervention.

RESULTS

Around 22% (n = 664) of surveillance colonoscopy referrals were inline with the guidelines, 51% (n = 1540) could be cancelled from the list and 27% (n = 816) could be given a new date. Implementing these recommendations reduced the average wait for a diagnostic colonoscopy from 76.8 to 56.0 days (P = 0.0022).

CONCLUSION

Following guidelines for surveillance colonoscopy can reduce waiting times for diagnostic colonoscopy. This allows a faster patient journey for diagnostic colonoscopy and a uniform plan for duration and frequency of surveillance colonoscopy. However, this action promoted serious debate on the social, moral and ethical issues.

Screening colonoscopy for colorectal cancer prevention: results from a German online registry on 269000 cases

BACKGROUND

The efficacy of screening colonoscopy in general use remains to be determined. Here we report data over a 39-month study period collected in a nationwide online registry.

STUDY

Data from consecutive screening colonoscopies performed on asymptomatic patients in the practices of 280 participating gastroenterologists (age 55-99 years) were collected in an online registry. The number and histology of colorectal polyps and carcinomas, complication rates of colonoscopy and polypectomy were registered. Advanced adenoma was defined as an adenoma of >or= 10 mm in diameter, villous or tubulovillous in histology, or presence of high-grade dysplasia.

RESULTS

A total of 269 144 colonoscopies (male 44%) were evaluated. Tubular, villous/tubulovillous adenomas and invasive cancers were found in 15.6, 3.7, and 0.8%, respectively. Advanced adenomas amounted to 7.1%. In 95% of polyps greater than 5mm and less than 30 mm immediate polypectomy was performed. In 399 of the 575 carcinomas with complete tumor node metastasis stages, which were detected during colonoscopy, early stages dominated (UICC stages I and II in 43 and 27%, respectively). Complication rate was low and no fatalities were observed: cardiopulmonary complication in 0.10% of the colonoscopies, bleeding in 0.8% of polypectomies most of which were managed endoscopically (surgery in 0.03% of polypectomies). Perforation occurred in 0.02% of the colonoscopies and 0.09% of polypectomies.

CONCLUSION

Colonic neoplasias are detected in about 20% of patients most of which are immediately removed by polypectomy at a low risk. Polypectomy of adenomas and low UICC stages in cancer patients during screening colonoscopy may be tools for fighting colorectal cancer mortality.

Survival benefit in a randomized clinical trial of faecal occult blood screening for colorectal cancer

BACKGROUND

Early detection of colorectal cancer could reduce cancer-specific mortality. The aim of this trial was to evaluate the effect of faecal occult blood test (FOBT) screening on colorectal cancer mortality in a Swedish population.

METHODS

All 68,308 citizens in Göteborg born between 1918 and 1931 were randomized to a screening or a control group at the age of 60-64 years. All were screened two to three times with rehydrated Hemoccult-II. Compliance was 70.0 per cent (23,916 individuals). Those with a positive test result were offered sigmoidoscopy and a double-contrast enema. The primary endpoint was death from colorectal cancer.

RESULTS

After a mean of 9 years from the last screening, there was a significant reduction in colorectal cancer mortality in the screening group compared with the control group. The overall risk ratio of death from colorectal cancer was 0.84 (95 per cent confidence interval 0.71 to 0.99). The groups did not differ in incidence of colorectal cancer or in overall mortality.

CONCLUSION

FOBT screening significantly reduces colorectal cancer mortality.

Cochrane systematic review of colorectal cancer screening using the fecal occult blood test (hemoccult): an update

BACKGROUND AND AIMS

Reducing mortality from colorectal cancer (CRC) may be achieved by the introduction of population-based screening programs. The aim of the systematic review was to update previous research to determine whether screening for CRC using the fecal occult blood test (FOBT) reduces CRC mortality and to consider the benefits, harms, and potential consequences of screening.

METHODS

We searched eight electronic databases (Cochrane Library, MEDLINE, EMBASE, CINAHL, PsychINFO, AMED, SIGLE, and HMIC). We identified nine articles describing four randomized controlled trials (RCTs) involving over 320,000 participants with follow-up ranging from 8 to 18 yr. The primary analyses used intention to screen and a secondary analysis adjusted for nonattendance. We calculated the relative risks and risk differences for each trial, and then overall, using fixed and random effects models.

RESULTS

Combined results from the four eligible RCTs indicated that screening had a 16% reduction in the relative risk (RR) of CRC mortality (RR 0.84, 95% confidence interval [CI] 0.78-0.90). There was a 15% RR reduction (RR 0.85, 95% CI 0.78-0.92) in CRC mortality for studies that used biennial screening. When adjusted for screening attendance in the individual studies, there was a 25% RR reduction (RR 0.75, 95% CI 0.66-0.84) for those attending at least one round of screening using the FOBT. There was no difference in all-cause mortality (RR 1.00, 95% CI 0.99-1.02) or all-cause mortality excluding CRC (RR 1.01, 95% CI 1.00-1.03).

CONCLUSIONS

The present review includes seven new publications and unpublished data concerning CRC screening using FOBT. This review confirms previous research demonstrating that FOBT screening reduces the risk of CRC mortality. The results also indicate that there is no difference in all-cause mortality between the screened and nonscreened populations.

Screening for colorectal cancer

Although there are several methods available for colon cancer screening, none is optimal. This article reviews methods for screening, including fecal occult blood tests, flexible sigmoidoscopy, colonoscopy, CT colonography, capsule endoscopy, and double contrast barium enema. A simple, inexpensive, noninvasive, and relatively sensitive screening test is needed to identify people at risk for developing advanced adenomas or colorectal cancer who would benefit from colonoscopy. It is hoped that new markers will be identified that perform better. Until then we fortunately have a variety of screening strategies that do work.

Screening for colorectal cancer using the faecal occult blood test, Hemoccult

BACKGROUND

Colorectal cancer is a leading cause of morbidity and mortality, especially in the Western world. The human and financial costs of this disease have prompted considerable research efforts to evaluate the ability of screening tests to detect the cancer at an early curable stage. Tests that have been considered for population screening include variants of the faecal occult blood test, flexible sigmoidoscopy and colonoscopy. Reducing mortality from colorectal cancer (CRC) may be achieved by the introduction of population-based screening programmes.

OBJECTIVES

To determine whether screening for colorectal cancer using the faecal occult blood test (guaiac or immunochemical) reduces colorectal cancer mortality and to consider the benefits, harms and potential consequences of screening.

SEARCH STRATEGY

Published and unpublished data for this review were identified by: Reviewing studies included in the previous Cochrane review; Searching several electronic databases (Cochrane Library, Medline, Embase, CINAHL, PsychInfo, Amed, SIGLE, HMIC); and Writing to the principal investigators of potentially eligible trials.

SELECTION CRITERIA

We included in this review all randomised trials of screening for colorectal cancer that compared faecal occult blood test (guaiac or immunochemical) on more than one occasion with no screening and reported colorectal cancer mortality.

DATA COLLECTION AND ANALYSIS

Data from the eligible trials were independently extracted by two reviewers. The primary data analysis was performed using the group participants were originally randomised to ('intention to screen'), whether or not they attended screening; a secondary analysis adjusted for non-attendence. We calculated the relative risks and risk differences for each trial, and then overall, using fixed and random effects models (including testing for heterogeneity of effects). We identified nine articles concerning four randomised controlled trials and two controlled trials involving over 320,000 participants with follow-up ranging from 8 to 18 years.

MAIN RESULTS

Combined results from the 4 eligible randomised controlled trials shows that participants allocated to screening had a 16% reduction in the relative risk of colorectal cancer mortality (RR 0.84, CI: 0.78-0.90). In the 3 studies that used biennial screening (Funen, Minnesota, Nottingham) there was a 15% relative risk reduction (RR 0.85, CI: 0.78-0.92) in colorectal cancer mortality. When adjusted for screening attendance in the individual studies, there was a 25% relative risk reduction (RR 0.75, CI: 0.66 - 0.84) for those attending at least one round of screening using the faecal occult blood test.

AUTHORS' CONCLUSIONS

Benefits of screening include a modest reduction in colorectal cancer mortality, a possible reduction in cancer incidence through the detection and removal of colorectal adenomas, and potentially, the less invasive surgery that earlier treatment of colorectal cancers may involve. Harmful effects of screening include the psycho-social consequences of receiving a false-positive result, the potentially significant complications of colonoscopy or a false-negative result, the possibility of overdiagnosis (leading to unnecessary investigations or treatment) and the complications associated with treatment.

Intravasation of barium sulphate at barium enema examination

We report a case of venous intravasation of barium sulphate occurring during a routine barium enema examination for investigation of rectal bleeding. The patient suffered a cardiopulmonary arrest, but made a full recovery after organ support in intensive care. Review of radiographs from the examination showed intravasated barium in pelvic vessels. We review the literature on this rare, but serious, complication of barium enema examination and suggest measures by which intravasation can be prevented.

Gastroenterologists utilize the referral for EGD to enhance colon cancer screening more effectively than primary care physicians

BACKGROUND

Colorectal cancer screening rates among patients with upper gastrointestinal symptoms undergoing oesophagogastroduodenoscopy have not been previously established. We hypothesize that gastroenterologists seize this opportunity more frequently than primary care providers.

AIMS

To assess colorectal cancer screening rates at the time of direct access oesophagogastroduodenoscopy and gastrointestinal clinic evaluation for upper gastrointestinal symptoms. To compare rates in the 6 months following the oesophagogastroduodenoscopy in both cohorts of patients.

METHODS

Retrospective review. primary care physician group: direct access oesophagogastroduodenoscopy (n = 247) vs. gastrointestinal group (n = 278). Multivariable regression analysis utilized to assess predictors of screening outcome.

RESULTS

Colorectal cancer screening at the time of referral was 54%. Among the 243 unscreened patients, an additional 29% in the primary care physician group vs. 59% in the gastrointestinal group completed colorectal cancer screening in 6 months of follow-up. Nearly 60% patients evaluated in gastrointestinal clinic for upper symptoms had documented discussion, and 99% of those patients underwent colonoscopy (P < 0.001). Gastrointestinal consultation increased the probability of colorectal cancer screening completion eightfold (95% CI 3.69-18.96).

CONCLUSIONS

At the time of evaluation for upper symptoms, half of patients were not current with colorectal cancer screening recommendations. Referrals for the direct access oesophagogastroduodenoscopy and, more importantly, the gastroenterology consult represent key opportunities for colorectal cancer screening education and improved compliance.

Colorectal cancer screening behavior in women attending screening mammography: Longitudinal trends and predictors

PURPOSE

Nationally representative surveys demonstrate that the adherence to screening mammography guidelines are associated with increased prevalence of colorectal cancer (CRC) screening; however, the incidence of CRC screening in the screening mammography population is unknown. Our purpose was to describe non-fecal occult blood test (FOBT) CRC screening utilization by women prior to and subsequent to screening mammography at a large academic medical center.

MATERIALS AND METHODS

Using the institutional administrative data base, 17,790 women aged 50 and older who underwent screening mammography between 1998 and 2002 were retrospectively identified. We determined that women were current with non-FOBT CRC screening at the time of mammography if they had undergone flexible sigmoidoscopy or double-contrast barium enema in the 5 years or colonoscopy since 1995, the earliest for which data are available. We excluded FOBT as a form of CRC screening because the administrative data base did not adequately capture episodes of FOBT. Women who were not current were considered eligible for non-FOBT CRC screening. We then assessed the number of women who underwent flexible sigmoidoscopy, barium enema, or colonoscopy within 12 months following mammography. Age, insurance status, Breast Imaging Reporting and Data System classification, recommendations after screening mammography and year of mammography were examined as potential predictors of non-FOBT CRC screening completion.

RESULTS

At the time of mammography, 13.3% women were current with non-FOBT CRC screening. Of women eligible for non-FOBT CRC screening at the time of mammography, 1.1% completed non-FOBT CRC screening within 12 months after mammography. The rate of non-FOBT CRC screening completion increased over time. After multivariate analysis, being insured by a commercial managed care organization or by Medicaid remained significant predictors of non-FOBT CRC screening.

CONCLUSION

The prevalence of non-FOBT CRC screening is low in the population of women undergoing screening mammography, with an incidence of 1.0%. Future studies should examine whether delivering CRC screening interventions at a screening mammography visit increase adherence to non-FOBT CRC screening.

The evaluation of rectal bleeding in adults. A cost-effectiveness analysis comparing four diagnostic strategies

BACKGROUND

Though primary care patients commonly present with rectal bleeding, the optimal evaluation strategy remains unknown.

OBJECTIVE

To compare the cost-effectiveness of four diagnostic strategies in the evaluation of rectal bleeding.

DESIGN

Cost-effectiveness analysis using a Markov decision model.

DATA SOURCES

Systematic review of the literature, Medicare reimbursement data, Surveillance, Epidemiology, and End Results (SEER) Cancer Registry.

TARGET POPULATION

Patients over age 40 with otherwise asymptomatic rectal bleeding.

TIME HORIZON

The patient's lifetime.

PERSPECTIVE

Modified societal perspective.

INTERVENTIONS

Watchful waiting, flexible sigmoidoscopy, flexible sigmoidoscopy followed by air contrast barium enema (FS+ACBE), and colonoscopy.

OUTCOME MEASURES

Incremental cost-effectiveness ratio.

RESULTS OF BASE-CASE ANALYSIS

The incremental cost-effectiveness ratio for colonoscopy compared with flexible sigmoidoscopy was 5,480 dollars per quality-adjusted year of life saved (QALY). Watchful waiting and FS+ACBE were more expensive and less effective than colonoscopy.

RESULTS OF SENSITIVITY ANALYSES

The cost of colonoscopy was reduced to 1,686 dollars per QALY when age at entry was changed to 45. Watchful waiting became the least expensive strategy when community procedure charges replaced Medicare costs, when age at entry was maximized to 80, or when the prevalence of polyps was lowered to 7%, but the remaining strategies provided greater life expectancy at relatively low cost. The strategy of FS+ACBE remained more expensive and less effective in all analyses. In the remaining sensitivity analyses, the incremental cost-effectiveness of colonoscopy compared with flexible sigmoidoscopy never rose above 34,000 dollars.

CONCLUSIONS

Colonoscopy is a cost-effective method to evaluate otherwise asymptomatic rectal bleeding, with a low cost per QALY compared to other strategies.

Screening of patients at average risk for colon cancer

Both the incidence and the mortality from colorectal cancer can be substantially reduced by primary and secondary prevention. There are many screening tests for colorectal cancer, and any test should result in a reduction in colorectal cancer incidence and mortality. If the age-eligible population undergoes these screening tests, the burden of colorectal cancer should be substantially reduced. The scientific evidence related to secondary prevention, specifically screening of individuals at average risk for colorectal cancer, is presently reviewed.

Colorectal cancer screening: scientific review

CONTEXT

Screening for colorectal cancer clearly reduces colorectal cancer mortality, yet many eligible adults remain unscreened. Several screening tests are available, and various professional organizations have differing recommendations on which screening test to use. Clinicians are challenged to ensure that eligible patients undergo colorectal cancer screening and to guide patients in choosing what tests to receive.

OBJECTIVE

To critically assess the evidence for use of the available colorectal cancer screening tests, including fecal occult blood tests, sigmoidoscopy, colonoscopy, double-contrast barium enema, and newer tests, such as virtual colonoscopy and stool-based molecular screening.

DATA SOURCES

All relevant English-language articles were identified using PubMed (January 1966-August 2002), published meta-analyses, reference lists of key articles, and expert consultation.

DATA EXTRACTION

Studies that evaluated colorectal cancer screening in healthy individuals and assessed clinical outcomes were included. Evidence from randomized controlled trials was considered to be of highest quality, followed by observational evidence. Diagnostic accuracy studies were evaluated when randomized controlled trials and observational studies were not available or did not provide adequate evidence. Studies were excluded if they did not evaluate colorectal screening tests and if they did not evaluate average-risk individuals.

DATA SYNTHESIS

Randomized controlled trials have shown that fecal occult blood testing can reduce colorectal cancer incidence and mortality. Case-control studies have shown that sigmoidoscopy is associated with a reduction in mortality, and observational studies suggest colonoscopy is effective as well. Combining fecal occult blood testing and sigmoidoscopy may decrease mortality and can increase diagnostic yield.

CONCLUSION

The recommendation that all men and women aged 50 years or older undergo screening for colorectal cancer is supported by a large body of direct and indirect evidence. At present, the available evidence does not currently support choosing one test over another.

Prospective evaluation of complications in outpatient GI endoscopy: a survey among German gastroenterologists

BACKGROUND

Although most diagnostic GI endoscopic procedures in Germany are performed on an outpatient basis, there is no large-scale prospective evaluation of complication rates.

METHODS

Ninety-four gastroenterologists and internists from all regions of Germany recorded the number of EGD, colonoscopies, and polypectomies performed over a period of 1 year. All serious complications occurring in relation to the procedure, including the use of medication, were recorded in a structured protocol.

RESULTS

A total of 110,469 EGDs, 82,416 colonoscopies, and 14,249 polypectomies were evaluated. The "reach-the-cecum-rate" was 97% (median). The overall complication rates for EGD, colonoscopy, and polypectomy were low compared with published data (0.009%, 0.02%, and 0.36%, respectively). The perforation rates were 0.0009%, 0.005%, and 0.06%, respectively, the rates of significant hemorrhage 0.002%, 0.001%, and 0.26%, respectively, and the mortality rates 0.0009%, 0.001%, and 0.007%, respectively. The rates of cardiorespiratory complications associated with EGD and colonoscopy were 0.005% and 0.01%, respectively. The overall complication rate for all procedures (diagnostic and therapeutic) was lower for gastroenterologists (1 per 5155 procedures) than internists (1 per 1539 procedures). Most of the adverse events associated with diagnostic endoscopy were attributable to use of medication. The severity score ranged from 2 to 5 for most of the adverse events occurring as a result of diagnostic procedures and 2 to 50 for polypectomy. The severity sum score per 10,000 procedures was 26 for EGD, 67 for colonoscopy, and 1185 for polypectomy.

CONCLUSIONS

Outpatient endoscopy performed in practice settings by German gastroenterologists and internists is safe. The low complication rates may partly be explained by the high degree of experience resulting from the larger numbers of procedures performed relative to the numbers performed by gastroenterologists in hospitals and in other countries.

Barium enema and endoscopy for the detection of colorectal neoplasia: sensitivity, specificity, complications and its determinants

AIM

To analyse sensitivity, specificity and complication rate of endoscopy, and barium enema for the detection of colorectal neoplasia.

MATERIALS AND METHODS

A MEDLINE search was performed (1980-2000) directed at the endoscopic and radiologic literature on barium enema. Articles were selected based on the type of study, availability of sensitivity and specificity values in sizeable patient groups, and reports on complications. Sixty articles were included in the analysis.

RESULTS

Endoscopy proved to have superior sensitivity for polyps in patients at high-risk for colorectal neoplasia. The role of endoscopy and radiology in average-risk screening populations is not known. Sensitivity and specificity rates ranged widely, probably due to bias. For the detection of small polyps endoscopy has superior performance, whereas sensitivity is similar for endoscopy and barium enema for the detection of larger (>1 cm) polyps and tumours. Overall, endoscopy is associated with a higher complication rate.

CONCLUSION

Endoscopy is the preferred detection method in high-risk patients. The role of endoscopy and radiology in a screening setting requires evaluation. This review provides the test characteristics of endoscopy and radiology which are relevant for a cost-effectiveness analysis. Double-contrast barium enema may play an important role for screening purposes, owing to its good sensitivity for detecting larger (>1 cm) polyps and its lack of major complications. de Zwart, I. M.et al. (2001). Clinical Radiology56, 401-409.

Colonic screening and surveillance

Screening for colorectal cancer has not obtained worldwide acceptance in spite of its proven survival benefit for average-risk persons and some high-risk groups. The incidence of and mortality from colorectal cancer are worrying in Europe as well as in the USA, Australia and Japan. The best evidence-based studies are those published on screening using faecal occult blood tests, endoscopic methods and different tumour markers having been evaluated to a lesser degree. Feasibility studies are necessary before massive screening can be undertaken because the results obtained from randomized studies may not be reproduced to a satisfactory degree in average- as well as high-risk populations. Primary prevention by dietary intervention and drugs has been studied in great detail, so far without any major breakthrough. This chapter will address different screening methods in populations with a varying risk of colorectal cancer, together with providing a short review of prevention and intervention strategies.

Screening for colorectal cancer using the faecal occult blood test, hemoccult

BACKGROUND

Colorectal cancer is a leading cause of illness and death in the Western world. In Australia, the United Kingdom and the United States, it is the second commonest cancer for women after breast cancer (age-standardised incidence 22-33 per 100,000), and men after prostate or lung cancer (age-standardised incidence 31-47 per 100,000) (Jeffs et al, 1996; Parkin et al, 1992). Just under half of all persons affected will die from their disease (Jeffs et al, 1996; Parkin et al, 1992) The human and financial costs of this disease have prompted considerable research efforts to evaluate the ability of screening tests to detect the cancer at an early curable stage. Tests which have been considered for screening include faecal occult blood tests, sigmoidoscopy and colonoscopy.

OBJECTIVES

To determine whether screening for colorectal cancer using the faecal occult blood test, Hemoccult reduces colorectal cancer mortality and to consider the benefits and harms of screening.

SEARCH STRATEGY

Published and unpublished data for this review were identified by: * retrieving studies included in a systematic review conducted by some of the authors in 1995, * searches of MEDLINE, Current Contents and the Cochrane Controlled Trials Register, * writing to trial lists.

SELECTION CRITERIA

All controlled trials of screening for colorectal cancer using Hemoccult were eligible for inclusion in the review.

DATA COLLECTION AND ANALYSIS

Data from the trials were independently extracted by two authors. Data analysis was performed using the group subjects were randomised to ('intention to screen'), whether or not they were ever screened. To estimate the effect of Hemoccult screening on colorectal cancer mortality, we calculated relative risks and risk differences for each trial, and then overall, using fixed and random effects models and tested for heterogeneity of effects. We calculated summary measures of effect including all trials and also for just the randomised controlled trials. We also calculated a summary measure of effect, adjusted for attendance at screening in each trial (not shown in Meta-view).

MAIN RESULTS

Meta-analysis of mortality results from the randomised controlled trials shows that those allocated to screening had a reduction in colorectal cancer mortality of 16% (RR 0.84, CI: 0.77-0.93). When adjusted for screening attendance in the individual studies, the mortality reduction is 23% (RR 0.77, CI: 0.57-0.89). Overall, if 10 000 people were offered a biennial Hemoccult screening program and two-thirds attended for at least one Hemoccult test, there would be 8.5 deaths (CI: 3.6-13.5) from colorectal cancer prevented over 10 years. However, the screening program would also result in 2 800 participants having at least one colonoscopy, if screening harms from the Minnesota trial are considered, and there would be 3.4 colonoscopy complications (perforation or haemorrhage). If screening harms from the Gothenburg trial are considered, approximately 600 participants would need at least one sigmoidoscopy and double contrast barium enema, resulting in 1.8 perforations or haemorrhages.

REVIEWER'S CONCLUSIONS

Screening benefits include reduction in colorectal cancer mortality, possible reduction in cancer incidence through detection and removal of colorectal adenomas and potentially, treatment of early colorectal cancers may involve less invasive surgery. Harmful effects of screening include the physical complications of colonoscopy, disruption to lifestyle, stress and discomfort of testing and investigations, and the anxiety caused by falsely positive screening tests. Although screening benefits are likely to outweigh harms for populations at increased risk of colorectal cancer, we need more information about the harmful effects of screening, the community's responses to screening and screening costs for different health care systems before widespread screening can be recommended.

A systematic review of the effects of screening for colorectal cancer using the faecal occult blood test, hemoccult

OBJECTIVE

To review effectiveness of screening for colorectal cancer with faecal occult blood test, Hemoccult, and to consider benefits and harms of screening.

DESIGN

Systematic review of trials of Hemoccult screening, with meta-analysis of results from the randomised controlled trials.

SUBJECTS

Four randomised controlled trials and two non-randomised trials of about 330 000 and 113 000 people respectively aged >=40 years in five countries.

MAIN OUTCOME MEASURES

Meta-analysis of effects of screening on mortality from colorectal cancer.

RESULTS

Quality of trial design was generally high, and screening resulted in a favourable shift in the stage distribution of colorectal cancers in the screening groups. Meta-analysis of mortality results from the four randomised controlled trials showed that those allocated to screening had a reduction in mortality from colorectal cancer of 16% (relative risk 0.84 (95% confidence interval 0.77 to 0.93)). When adjusted for attendance for screening, this reduction was 23% (relative risk 0.77 (0.57 to 0.89)) for people actually screened. If a biennial Hemoccult screening programme were offered to 10 000 people and about two thirds attended for at least one Hemoccult test, 8.5 (3.6 to 13.5) deaths from colorectal cancer would be prevented over a period of 10 years.

CONCLUSION

Although benefits of screening are likely to outweigh harms for populations at high risk of colorectal cancer, more information is needed about the harmful effects of screening, the community's responses to screening, and costs of screening for different healthcare systems before widespread screening can be recommended.