Risk of colorectal cancer after colonoscopy compared with flexible sigmoidoscopy or no lower endoscopy among older patients in the United States, 1998-2005

Colonoscopic screening is associated with reduced Colorectal Cancer incidence and mortality: a systematic review and meta-analysis

It is the great priority to detect colorectal cancer (CRC) as early as possible, finally to reduce the incidence and mortality of CRC. However, although colonoscopy is recommended in many consensuses, yet no one systematic review is conducted to figure out how colonoscopy could change the incidence and mortality. In our study, we conducted a comprehensive meta-analysis to evaluate the association between colonoscopy screening and the incidence or mortality of CRC. PubMed, EMBASE, and PMC database were systematically searched from their inception to June 2020. A total of 13 cohort and 16 case-control studies comprising 4,713,778 individuals were obtained in this review. Our results showed that colonoscopy was associated with a 52% RR reduction in incidence of CRC (RR: 0.48, 95% CI: 0.46-0.49) and 62% RR reduction in mortality of CRC (RR: 0.38, 95% CI: 0.36-0.40). Subgroup analysis of different interventions, study design, country, sample size, age or sex showed that the incidence and mortality reduction remained consistent, and colonoscopy screening had the same effect on people below and above 50. Our study indicated that colonoscopy could significantly reduce the incidence and mortality of CRC.

Anatomical distribution and detection rate of colorectal neoplasms according to age in the colonoscopic screening of a Korean population

Purpose

Because data as a basis for the determination of proper age and modality for screening of colorectal neoplasms is lacking, we evaluated detection rates and anatomical distribution of colorectal neoplasms according to age in healthy individuals who underwent total colonoscopy for health checkup.

Methods

A total of 16,100 cases that had received the colonoscopic examination from January to December in 2014 were analyzed. The total number of individuals who received total colonoscopy were divided by the number of individuals harboring colorectal adenoma to calculate the detection rate of colorectal adenoma. Individuals ≤50 years old were classified as young-age group and aged >50 were old-age group. Differences in anatomical locations of colorectal neoplasms were analyzed in the 2 age groups by chi-square test. Risk factors for colorectal adenoma in each age group were analyzed using univariate and multivariate logistic regression analyses.

Results

Detection rates of colorectal adenoma were 13.7% in all cases and 12.8% for those in their 40's. The main anatomical location of colorectal adenoma was proximal colon in both age groups (P < 0.001). Hyperplastic polyp was mainly distributed to the distal colon in both age groups (P < 0.001). Distal colon was the major site for colorectal cancer in the old-age group (P = 0.001). Proximal location of neoplasms was a risk factor for colorectal adenoma in both age groups with multivariate analysis.

Conclusion

These data could be the bases for earlier initiation of screening for colorectal neoplasms with total colonoscopy to detect clinically significant colorectal polyps.

Decreased Risk of Colorectal Cancer after Colonoscopy in Patients 76-85 Years Old in the United States

BACKGROUND/AIMS

The benefits of colonoscopy in reducing colorectal cancer (CRC) risk for patients over 75 years are controversial. We aimed to determine whether colonoscopy use is associated with a decreased risk of CRC in patients 76-85 years old in the United States (US).

PATIENTS AND METHODS

All patients in the Medicare 5% random sample of the Surveillance, Epidemiology and End Results-Medicare linked database 76-85 years old at outpatient colonoscopy between January 1, 1998 and December 31, 2002 were identified. Using the Kaplan-Meier method, we estimated the cumulative incidence of CRC in the above-mentioned colonoscopy group and compared with the control group of patients without colonoscopy. All patients were followed until diagnosis of CRC or carcinoma in situ, death or December 31, 2005. The multivariate Cox proportional hazards model was used in statistical analysis. CRC was separated by location into distal vs. proximal CRC in subgroup analysis.

RESULTS

Of 5,701 patients in the colonoscopy group, 37 (0.65%) patients were diagnosed with CRC, compared to 379 (1.55%) out of 24,437 patients in the control group (p < 0.001). The cumulative incidences of distal and proximal CRC were lower in the colonoscopy group compared to those in the control group (5-year distal CRC: 0.26 vs. 0.77%; 5-year proximal CRC: 0.43 vs. 0.79%, both p < 0.05). In multivariate Cox regression, colonoscopy was associated with decreased risk of all CRC (hazard ratio ((HR) 0.42, 95% CI 0.28-0.65), distal CRC (HR 0.36, 95% CI 0.18-0.70), and proximal CRC (HR 0.53, 95% CI 0.30-0.92)).

CONCLUSION

Among patients 76-85 years old in the United States, colonoscopy use was associated with decreased risks of both distal and proximal CRC, with a smaller risk reduction in distal colon. Due to inherent limitations associated with our retrospective design, future prospective studies are needed to validate these findings.

Colorectal cancer mortality reduction is associated with having at least 1 colonoscopy within the previous 10 years among a population-wide cohort of screening age

BACKGROUND AND AIMS

Colonoscopy has been demonstrated to be effective in colorectal cancer (CRC) mortality reduction, although current screening guidelines have yet to be evaluated. We assessed the protective benefit of colonoscopy within the previous 10 years and whether this effect is maintained with age.

METHODS

We used administrative data to compare risk of CRC death (CCD) across colonoscopy utilization among a population-wide cohort comprising individuals aged 60 to 80 years (N = 1,509,423). Baseline and time-dependent colonoscopy exposure models were assessed in the context of competing "other causes of death" (OCDs). Cumulative incidence of CCD and OCD across colonoscopy exposure, over follow-up, was estimated. Relative hazards were computed by age strata (60-69 years, 70-74 years, 75+ years) and proximal and distal cancer subsites.

RESULTS

At least 1 colonoscopy during 10 years before baseline was estimated to provide a 51% reduced hazard of CCD (hazard ratio [HR] 0.49; 95% confidence interval [CI], 0.45-0.54) over the following 8 years. When colonoscopy was modeled as a time-dependent covariate, the risk of CCD was further diminished (multivariable-adjusted HR 0.36; 95% CI, 0.33-0.38). Stratified analyses suggested moderately attenuated CCD risk reduction among the oldest age group; however, consideration of OCDs suggest that this is related to competing risks. CCD risk reduction related to colonoscopy was lower for proximal cancers.

CONCLUSIONS

Colonoscopy within the previous 10 years provides substantial protective benefit for average-risk individuals over 60 years. CCD risk reduction may be maintained well beyond 74 years, a common upper age limit recommended by screening guidelines.

Colonoscopy Reduces Colorectal Cancer Incidence and Mortality in Patients With Non-Malignant Findings: A Meta-Analysis

OBJECTIVES

Observational studies have shown that colonoscopy reduces colorectal cancer (CRC) incidence and mortality in the general population. We aimed to conduct a meta-analysis quantifying the magnitude of protection by colonoscopy, with screening and diagnostic indications, against CRC in patients with non-malignant findings and demonstrating the potentially more marked effect of screening over diagnostic colonoscopy.

METHODS

PubMed, EMBASE, and conference abstracts were searched through 30 April 2015. The primary outcomes were overall CRC incidence and mortality. Pooled relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random-effect models.

RESULTS

Eleven observational studies with a total of 1,499,521 individuals were included. Pooled analysis showed that colonoscopy was associated with a 61% RR reduction in CRC incidence (RR: 0.39; 95% CI: 0.26-0.60; I(2)=93.6%) and a 61% reduction in CRC mortality (RR: 0.39; 95% CI: 0.35-0.43; I(2)=12.0%) in patients with non-malignant findings, although there was high heterogeneity for the outcome of CRC incidence. After excluding one outlier study, there was low heterogeneity for the outcome of incidence (I(2)=44.7%). Subgroup analysis showed that the effect of screening colonoscopy was more prominent, corresponding to an 89% reduction in CRC incidence (RR: 0.11; 95% CI: 0.08-0.15), in comparison with settings involving diagnostic colonoscopy (RR: 0.51; 95% CI: 0.43-0.59; P<0.001).

CONCLUSIONS

On the basis of this meta-analysis of observational studies, CRC incidence and mortality in patients with non-malignant findings are significantly reduced after colonoscopy. The effect of screening colonoscopy on CRC incidence is more marked than diagnostic colonoscopy.

Non-physician endoscopists: A systematic review

AIM: To examine the available evidence on safety, competency and cost-effectiveness of nursing staff providing gastrointestinal (GI) endoscopy services.

METHODS: The literature was searched for publications reporting nurse endoscopy using several databases and specific search terms. Studies were screened against eligibility criteria and for relevance. Initial searches yielded 74 eligible and relevant articles; 26 of these studies were primary research articles using original datasets relating to the ability of non-physician endoscopists. These publications included a total of 28883 procedures performed by non-physician endoscopists.

RESULTS: The number of publications in the field of non-specialist gastrointestinal endoscopy reached a peak between 1999 and 2001 and has decreased thereafter. 17/26 studies related to flexible sigmoidoscopies, 5 to upper GI endoscopy and 6 to colonoscopy. All studies were from metropolitan centres with nurses working under strict supervision and guidance by specialist gastroenterologists. Geographic distribution of publications showed the majority of research was conducted in the United States (43%), the United Kingdom (39%) and the Netherlands (7%). Most studies conclude that after appropriate training nurse endoscopists safely perform procedures. However, in relation to endoscopic competency, safety or patient satisfaction, all studies had major methodological limitations. Patients were often not randomized (21/26 studies) and not appropriately controlled. In relation to cost-efficiency, nurse endoscopists were less cost-effective per procedure at year 1 when compared to services provided by physicians, due largely to the increased need for subsequent endoscopies, specialist follow-up and primary care consultations.

CONCLUSION: Contrary to general beliefs, endoscopic services provided by nurse endoscopists are not more cost effective compared to standard service models and evidence suggests the opposite. Overall significant shortcomings and biases limit the validity and generalizability of studies that have explored safety and quality of services delivered by non-medical endoscopists.

Screening colonoscopy versus sigmoidoscopy: implications of a negative examination for cancer prevention and racial disparities in average-risk patients

BACKGROUND

Both colonoscopy and flexible sigmoidoscopy are accepted procedures for colorectal cancer (CRC) screening in the United States.

OBJECTIVE

To compare risk of CRC after negative findings on screening colonoscopy versus sigmoidoscopy and to evaluate racial/ethnic disparities in postscreening CRC.

DESIGN

Retrospective, comparative cohort study.

SETTING

Integrated community-based health-care system.

PATIENTS

Average-risk patients 50 to 75 years of age with negative findings on an initial endoscopic screening examination from January 2000 to December 2010.

INTERVENTIONS

Colonoscopy versus sigmoidoscopy as the initial screening procedure.

MAIN OUTCOME MEASUREMENTS

Incident cases of CRC identified via a prospective internal cancer registry, risk of CRC determined by Cox regression adjusted for age, sex, race/ethnicity, and comorbidity.

RESULTS

The study cohort included 138,297 patients (42,938 patients with negative findings on colonoscopy and 95,359 with negative findings on sigmoidoscopy). The median age was 57.9 years (interquartile range 53.0-64.1 years). Women comprised 51.8% of the cohort with 42.2% non-Hispanic white patients, 24.1% Hispanic patients, 10.7% non-Hispanic black patients, 9.7% Asian patients, and 13.3% other/unknown. A total of 241 cases of CRC was detected during 553,543 person-years of follow-up. The adjusted hazard ratio (HR) of postscreening CRC was 0.42 (95% confidence interval [CI], 0.28-0.64; P < .0001) for colonoscopy versus sigmoidoscopy. Risk reduction was primarily among proximal tumors (adjusted HR 0.30; 95% CI, 0.16-0.57). Non-Hispanic black patients were at higher risk of postscreening CRC compared with non-Hispanic white patients (adjusted HR 1.71; 95% CI, 1.20-2.42); however, this disparity was noted only in the sigmoidoscopy cohort.

LIMITATIONS

Retrospective study with potential selection bias and residual confounding.

CONCLUSIONS

Negative screening colonoscopy was associated with decreased incidence of subsequent CRC and a decrease in disparities compared with negative sigmoidoscopy findings in this large, community-based setting.

Colorectal cancer prevention in Europe: burden of disease and status of screening programs

Colorectal cancer is a major public health challenge worldwide. In Europe it is the first malignancy in terms of incidence and the second in terms of mortality in both genders. Despite evidence indicating that removal of premalignant and early-stage cancer lesion scan greatly reduce mortality, remarkable differences are still found among countries both in terms of organized screening programs and of the tests used. In 2003 the European Council recommended that priority be given to activation of organized cancer screening programs, and various states have been making significant efforts to adopt effective prevention programs with international quality standards and centralizing screening organization and result evaluation. After a 2008 European Union report on the state of screening program, activation highlighted that little more than 50% (12/22) of Member States had colorectal cancer screening programs, Screening programs have been adopted or earlier pilot projects have been extended nationwide. This paper examines the state of activation and the screening strategies of colorectal cancer screening programs in EU States as of July 2013.

Effect of screening sigmoidoscopy and screening colonoscopy on colorectal cancer incidence and mortality: systematic review and meta-analysis of randomised controlled trials and observational studies

OBJECTIVES

To review, summarise, and compare the evidence for effectiveness of screening sigmoidoscopy and screening colonoscopy in the prevention of colorectal cancer occurrence and deaths.

DESIGN

Systematic review and meta-analysis of randomised controlled trials and observational studies.

DATA SOURCES

PubMed, Embase, and Web of Science. Two investigators independently extracted characteristics and results of identified studies and performed standardised quality ratings.

ELIGIBILITY CRITERIA

Randomised controlled trials and observational studies in English on the impact of screening sigmoidoscopy and screening colonoscopy on colorectal cancer incidence and mortality in the general population at average risk.

RESULTS

For screening sigmoidoscopy, four randomised controlled trials and 10 observational studies were identified that consistently found a major reduction in distal but not proximal colorectal cancer incidence and mortality. Summary estimates of reduction in distal colorectal cancer incidence and mortality were 31% (95% confidence intervals 26% to 37%) and 46% (33% to 57%) in intention to screen analysis, 42% (29% to 53%) and 61% (27% to 79%) in per protocol analysis of randomised controlled trials, and 64% (50% to 74%) and 66% (38% to 81%) in observational studies. For screening colonoscopy, evidence was restricted to six observational studies, the results of which suggest tentatively an even stronger reduction in distal colorectal cancer incidence and mortality, along with a significant reduction in mortality from cancer of the proximal colon. Indirect comparisons of results of observational studies on screening sigmoidoscopy and colonoscopy suggest a 40% to 60% lower risk of incident colorectal cancer and death from colorectal cancer after screening colonoscopy even though this incremental risk reduction was statistically significant for deaths from cancer of the proximal colon only.

CONCLUSIONS

Compelling and consistent evidence from randomised controlled trials and observational studies suggests that screening sigmoidoscopy and screening colonoscopy prevent most deaths from distal colorectal cancer. Observational studies suggest that colonoscopy compared with flexible sigmoidoscopy decreases mortality from cancer of the proximal colon. This added value should be examined in further research and weighed against the higher costs, discomfort, complication rates, capacities needed, and possible differences in compliance.

Advanced colorectal polyp detection techniques

A long-term follow-up of the landmark National Polyp Study recently showed that colonoscopy was associated with critical clinical benefit, including reduced overall death rate, colorectal cancer (CRC) death rate, and CRC incidence Zauber et al. (N Engl J Med 366(8):687-96, 2012). This and other recent studies emphasize the need for high-quality colonoscopy to realize maximal benefit. Adenoma detection has emerged as an important predictor of quality colonoscopy. Studies from Europe have shown that individuals whose colonoscopy was performed by a physician with high adenoma detection have a much lower likelihood of interval CRC. Studies now suggest that it is possible to train endoscopists to improve their adenoma detection rate. The specific methods associated with higher quality colonoscopy include careful inspection behind folds, washing the colon surface, adequate insufflation, and recognition of subtle flat polyps. Use of high-definition white light colonoscopy, chromoendoscopy, and cap-fitted colonoscopy has also been studied as potential methods for increasing adenoma detection. We will review these methods and techniques in this article.