Protection by endoscopy against death from colorectal cancer. A case-control study among veterans

A Multi-Centre Study to Risk Stratify Colorectal Polyp Surveillance Patients Utilising Volatile Organic Compounds and Faecal Immunochemical Test

Simple Summary

A total of 15% of the annual colonoscopies are undertaken for polyp surveillance, and this causes strain on already stretched endoscopy services in the U.K. Hence, there is an urgent need to triage and prioritise patients with high-risk findings. The performance of the faecal immunochemical test is not adequate to be used within polyp surveillance. In light of this, we investigated the usefulness of urinary volatile organic compounds for the detection of high-risk findings. We confirmed that urinary volatile organic compounds can be used to triage patients with high-risk findings. It can be used alone or in combination with faecal immunochemical tests.

Abstract

(1) Background: The service capacity for colonoscopy remains constrained, and while efforts are being made to recover elective services, polyp surveillance remains a challenge. (2) Methods: This is a multi-centre study recruiting patients already on polyp surveillance. Stool and urine samples were collected for the faecal immunochemical test (FIT) and volatile organic compounds (VOC) analysis, and all participants then underwent surveillance colonoscopy. (3) Results: The sensitivity and specificity of VOC for the detection of a high-risk finding ((≥2 premalignant polyps including ≥1 advanced polyp or ≥5 premalignant polyps) were 0.94 (95% CI, 0.88 to 0.98) and 0.69 (95% CI, 0.64 to 0.75) respectively. For FIT, the sensitivity was (≥10 µg of haemoglobin (Hb) / g faeces) 0.54 (95% CI, 0.43 to 0.65) and the specificity was 0.79 (95% CI, 0.73 to 0.84). The probability reduction for having a high-risk finding following both negative VOC and FIT will be 24% if both tests are applied sequentially. (4) Conclusion: The diagnostic performance of VOC is superior to FIT for the detection of a high-risk finding. The performance further improves when VOC is applied together with FIT sequentially (VOC first and then FIT). VOC alone or the combination of VOC and FIT can be used as a triage tool for patients awaiting colonoscopy within a polyp surveillance population, especially in resource-constrained healthcare systems.

Measuring and Improving Quality of Colonoscopy for Colorectal Cancer Screening

Colorectal cancer (CRC) is largely preventable, yet it remains a major public health issue as it is the third most common and deadly malignancy in the United States. While there are many ways to screen for CRC, colonoscopy remains the gold standard as it is the only test that is both cancer-detecting and cancer-preventing through removal of precancerous polyps. Through identifying and removing neoplastic lesions, colonoscopy reduces CRC incidence by 31%-91% and CRC mortality by 65%-88%. However, colonoscopy is not an infallible test-there is a chance for missed lesions during the exam and there is substantial variation in outcomes among endoscopists. To enhance the quality of colonoscopic exams, and ultimately to improve CRC outcomes, quality indicators have been developed for measuring endoscopists' performance. In this review, we describe the colonoscopic quality indicators and benchmarks recommended by the American Society for Gastrointestinal Endoscopy/American College of Gastroenterology Task Force on Quality in Endoscopy for screening colonoscopies in average-risk individuals. Measuring and monitoring endoscopists' performance on these measures are critical first steps in striving toward conducting high quality exams. We also review the evidence for interventions that aim to improve critical measures including adenoma detection rate, withdrawal time, cecal intubation, and bowel preparation quality. Finally, we provide a preview of the forthcoming Advancing Care for Appropriate Colon Health Merit-Based Incentive Payment System Value Pathway by the Centers for Medicare & Medicaid Services and its potential impact on clinical practice.

Colonoscopy screening and surveillance guidelines

The Colonoscopy Screening and Surveillance Guidelines were developed by the Japan Gastroenterological Endoscopy Society as basic guidelines based on the scientific methods. The importance of endoscopic screening and surveillance for both detection and post-treatment follow-up of colorectal cancer has been recognized as essential to reduce disease mortality. There is limited high-level evidence in this field; therefore, we had to focus on the consensus of experts. These clinical practice guidelines consist of 20 clinical questions and eight background knowledge topics that have been determined as the current guiding principles.

Risk of Colorectal Cancer and Cancer Related Mortality After Detection of Low-risk or High-risk Adenomas, Compared With No Adenoma, at Index Colonoscopy: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The risk of metachronous colorectal cancer (CRC) among patients with no adenomas, low-risk adenomas (LRAs), or high-risk adenomas (HRAs), detected at index colonoscopy, is unclear. We performed a systematic review and meta-analysis to compare incidence rates of metachronous CRC and CRC-related mortality after a baseline colonoscopy for each group.

METHODS

We searched the PubMed, Embase, Google Scholar, and Cochrane databases for studies that reported the incidence of CRC and adenoma characteristics after colonoscopy. The primary outcome was odds of metachronous CRC and CRC-related mortality per 10,000 person-years of follow-up after baseline colonoscopy for all the groups.

RESULTS

Our final analysis included 12 studies with 510,019 patients (mean age, 59.2 ± 2.6 years; 55% male; mean duration of follow up, 8.5 ± 3.3 years). The incidence of CRC per 10,000 person-years was marginally higher for patients with LRAs compared to those with no adenomas (4.5 vs 3.4; odds ratio [OR], 1.26; 95% CI, 1.06-1.51; I²=0), but significantly higher for patients with HRAs compared to those with no adenoma ( 13.8 vs 3.4; odds ratio [OR], 2.92; 95% CI, 2.31-3.69; I²=0 ) and patients with HRAs compared to LRAs (13.81 vs 4.5; OR, 2.35; 95% CI, 1.72-3.20; I²=55%). However, the CRC-related mortality per 10,000 person-years did not differ significantly for patients with LRAs compared to no adenomas (OR, 1.15; 95% CI, 0.76-1.74; I²=0) but was significantly higher in persons with HRAs compared with LRAs (OR, 2.48; 95% CI, 1.30-4.75; I²=38%) and no adenomas (OR, 2.69; 95% CI, 1.87-3.87; I²=0).

CONCLUSIONS

The results of this systematic review and meta-analysis demonstrate that the risk of metachronous CRC and mortality is significantly higher for patients with HRAs, but this risk is very low in patients with LRAs, comparable to patients with no adenomas. Follow-up of patients with LRAs detected at index colonoscopy should be the same as for persons with no adenomas.

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.

Low Colorectal Cancer Screening Uptake and Persistent Disparities in an Underserved Urban Population

Colorectal cancer screening has increased substantially in New York City in recent years. However, screening uptake measured by telephone surveys may not fully capture rates among underserved populations. We measured screening completion within 1 year of a primary care visit among previously unscreened patients in a large urban safety-net hospital and identified sociodemographic and health-related predictors of screening.We identified 21,256 patients ages 50 to 75 who were seen by primary care providers (PCP) in 2014, of whom 14,425 (67.9%) were not up-to-date with screening. Because PCPs facilitate the majority of screening, we compared patients who received screening within 1 year of an initial PCP visit to those who remained unscreened using multivariable logistic regression.Among patients not up-to-date with screening at study outset, 11.5% (1,658 patients) completed screening within 1 year of a PCP visit. Asian race, more PCP visits, and higher area-level income were associated with higher screening completion. Factors associated with remaining unscreened included morbid obesity, ever smoking, Elixhauser comorbidity index of 0, and having Medicaid/Medicare insurance. Age, sex, language, and travel time to the hospital were not associated with screening status. Overall, 39.9% of patients were up-to-date with screening by 2015.In an underserved urban population, colorectal cancer screening disparities remain, and overall screening uptake was low. Because more PCP visits were associated with modestly higher screening completion at 1 year, additional community-level education and outreach may be crucial to increase colorectal cancer screening in underserved populations.

ACR Appropriateness Criteria® Colorectal Cancer Screening

This review summarizes the relevant literature regarding colorectal screening with imaging. For individuals at average or moderate risk for colorectal cancer, CT colonography is usually appropriate for colorectal cancer screening. After positive results on a fecal occult blood test or immunohistochemical test, CT colonography is usually appropriate for colorectal cancer detection. For individuals at high risk for colorectal cancer (eg, hereditary nonpolyposis colorectal cancer, ulcerative colitis, or Crohn colitis), optical colonoscopy is preferred because of its ability to obtain biopsies to detect dysplasia. After incomplete colonoscopy, CT colonography is usually appropriate for colorectal cancer screening for individuals at average, moderate, or high risk. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Comparing the Real-World Effectiveness of Competing Colonoscopy Preparations: Results of a Prospective Trial

OBJECTIVES

National societies provide little guidance regarding which colonoscopy bowel preps are best tolerated and most effective; this reflects a lack of comparative effectiveness studies that directly evaluate the available preps in a "real-world" setting. To address this gap, we conducted a prospective, commercially unfunded comparative effectiveness study of currently available bowel preps and measured their impact on bowel cleansing.

METHODS

We included patients aged ≥18 years, who presented for an outpatient colonoscopy at a large medical center serving more than 70 academic and community-based endoscopists who are free to prescribe the bowel prep of their choice. The primary outcome was bowel cleansing quality as measured by the Boston Bowel Preparation Scale. We performed regression models with random effects on the outcomes to adjust for confounding.

RESULTS

Approximately 4,339 colonoscopies were performed by 75 endoscopists. Magnesium citrate, MiraLAX with Gatorade, MoviPrep, OsmoPrep, Prepopik/Clenpiq, and Suprep all had significantly higher prep tolerability compared with GoLYTELY (all P < 0.05). For bowel cleansing, Suprep (7.28 ± 1.66; P < 0.001), MoviPrep (7.11 ± 1.62; P = 0.004), and MiraLAX with Gatorade (7.09 ± 1.64; P < 0.001) had higher total Boston Bowel Preparation Scale scores compared with GoLYTELY (6.67 ± 1.87); there were no significant differences among the remaining preps. Split-prep dosing was associated with better cleansing; however, men, opioid and tricyclic antidepressent users, and patients with diabetes and cirrhosis had worse cleansing (all P < 0.05).

CONCLUSIONS

In this prospective, real-world comparative effectiveness study of available bowel preps, we found that MiraLAX with Gatorade, MoviPrep, and Suprep were prospectively associated with superior tolerability and bowel cleansing.

Willingness to Pay for Colorectal Cancer Screening and Effect of Copayment in Southern Thailand

Background:

The incidence rate of colorectal cancer in Thailand is increasing. Hence, the nationwide screening programme with copayment is being considered. There are two proposed screening alternatives: annual fecal immunochemical test (FIT) and once-in-10-year colonoscopy. A copayment for FIT is 60 Thai baht (THB) per test (≈ 1.7 USD); a copayment for colonoscopy is 2,300 THB per test (≈ 65.5 USD).

Methods:

The willingness to pay (WTP) technique, which is theoretically founded on a cost-benefit analysis, was used to assess an effect of copayment on the uptake. Subjects were patients aged 50-69 years without cancer or screening experience. WTP for the proposed tests was elicited.

Results:

Nearly two thirds of subjects were willing to pay for FIT. Less than half of subjects were willing to pay for colonoscopy. Among them, median WTP for both tests was greater than the proposed copayments. In a probit model, knowing CRC patient and presence of companion were associated with non-zero WTP for FIT. Presence of companion, female, and family history of cancer were associated with non-zero WTP for colonoscopy. After adjustment for starting price in the linear model, marital status, drinking behavior, and risk attitude were associated with WTP. None of factors was significant for colonoscopy. Uptake decreased as levels of copayment increased. At proposed copayments, the uptake rates of 59.8% and 21.6% were estimated for colonoscopy and FIT respectively. The demand for FIT was price inelastic; the demand for colonoscopy was price elastic. Estimates of optimal copayment were 62.1 THB for FIT and 460.2 THB for colonoscopy. At the optimal copayment, uptake rates would be 59.8% for FIT and 42.3% for colonoscopy.

Conclusion(s):

More subjects were willing to pay for FIT than for colonoscopy (59.0% versus 46.5%). The estimated uptake rates were 59.8% and 21.6% for colonoscopy and FIT at the proposed copayments.

Public health impact of colonoscopy use on colorectal cancer mortality in Germany and the United States

BACKGROUND AND AIMS

Colonoscopy has been demonstrated to be effective in reducing colorectal cancer (CRC) incidence and mortality and has been widely used for primary CRC screening in Germany and the United States. We performed a population-based analysis to evaluate and compare the public health impact of recent colonoscopy use on CRC deaths among adults aged 55 to 79 years in Germany and the United States from 2008 to 2011.

METHODS

The epidemiologic metrics of attributable fraction and prevented fraction as well as the impact numbers were calculated using colonoscopy utilization data from nationally representative health surveys, relative risk estimates from medical literature, and CRC death registry data.

RESULTS

Overall, 36.6% (95% credible interval [CrI], 27.3%-45.5%) of CRC deaths in Germany were estimated to be attributable to nonuse of colonoscopy, compared with the U.S. estimates of 38.2% (95% CrI, 28.6%-47.1%) and 33.6% (95% CrI, 24.8%-42.2%) for years 2008 to 2009 and 2010 to 2011, respectively. The proportion of CRC deaths theoretically prevented by colonoscopy use within 10 years was 30.7% (95% CrI, 24.8%-35.7%) in Germany, whereas in the United States this proportion ranged from 29.0% (95% CrI, 23.4%-33.6%) for 2008 to 2009 to 33.9% (95% CrI, 27.4%-39.2%) for 2010 to 2011.

CONCLUSIONS

Recent colonoscopy use is likely to have prevented a considerable fraction of CRC mortality in both countries, and more deaths could be avoided by increasing colonoscopy use in the target population. Attributable and prevented fraction can provide valuable information on the public health impact of colonoscopy use and guide policymaking.

Colonoscopy reduces colorectal cancer mortality: A multicenter, long-term, colonoscopy-based cohort study

Background

There are limited colonoscopy-based cohort data concerning the effectiveness of colonoscopy in reducing colorectal cancer deaths. The aim of this study was to clarify whether colonoscopy reduces colorectal cancer mortality.

Methods

A cohort of 18,816 patients who underwent colonoscopy without a diagnosis of colorectal cancer between 2001 and 2010 at high colonoscopy procedure volume centers was selected. Patient characteristics and colonoscopy findings were assessed. The main endpoint was colorectal cancer death (all, right-sided, and left-sided cancers), and data were censored at the time of the final visit or the final colonoscopy. The standardized all colorectal, colon, and rectal cancer mortality rates were estimated with reference to those of the general Japanese population. Additional outcome was all- cause death and the standardized all-cause mortality rate was also estimated.

Results

The total observed person-year mortality for colorectal cancer was 67,119. Of these, 4, 3, and 1 patients died from colorectal, colon, and rectal cancers, respectively; these values were significantly lower than the number of expected deaths in the general population, estimated to be 53.1, 34.0, and 19.1, respectively. The standardized mortalities for all colorectal, colon, and rectal cancers were 0.08 (95% confidence interval (CI), 0.02–0.17), 0.09 (95% CI, 0.02–0.22), and 0.05 (95% CI, 0.0002–0.21), respectively. There were 586 all-cause deaths (3.11%) during the observation period. The standardized all-cause mortality ratios were 0.22 (95% CI, 0.206–0.23).

Conclusions

The colorectal cancer mortality of patients who received colonoscopy without colorectal cancer diagnosis decreased significantly compared with that of individuals in the general population. These results were compatible even in patients with right-sided colon cancer.

The Use of Deceased Controls in Epidemiologic Research: A Systematic Review

Scholarly debate on the use of deceased controls in epidemiologic research continues. This systematic review examined published epidemiologic research using deceased persons as a control group. A systematic search of 5 major biomedical literature databases (MEDLINE, CINAHL, PsycINFO, Scopus, and EMBASE) was conducted, using variations of the search terms "deceased" and "controls" to identify relevant peer-reviewed journal articles. Information was sought on study design, rationale for using deceased controls, application of theoretical principles of control selection, and discussion of the use of deceased controls. The review identified 134 studies using deceased controls published in English between 1978 and 2015. Common health outcomes under investigation included cancer (n = 31; 23.1%), nervous system diseases (n = 26; 19.4%), and injury and other external causes (n = 22; 16.4%). The majority of studies used deceased controls for comparison with deceased cases (n = 95; 70.9%). Investigators rarely presented their rationale for control selection (n = 25/134; 18.7%); however, common reasons included comparability of information on exposures, lack of appropriate controls from other sources, and counteracting bias associated with living controls. Comparable accuracy was the most frequently observed principle of control selection (n = 92; 68.7%). This review highlights the breadth of research using deceased controls and indicates their appropriateness in studies using deceased cases.

MicroRNA-186-5p overexpression modulates colon cancer growth by repressing the expression of the FAM134B tumour inhibitor

OBJECTIVES

The role and underlying mechanism of miR-186-5p in colorectal cancer remain unknown. The present study aims to examine the various cellular effects of miR-186-5p in the carcinogenesis of colorectal cancer. Also, the interacting targets and association of clinicopathological factors with miR-186-5p expression in patients with colorectal cancer were analysed.

METHODS

The miR-186-5p expression levels in colorectal cancer tissues (n=126) and colon cancer cell lines (n=3) were analysed by real-time PCR. Matched non-neoplastic colorectal tissues and a non-neoplastic colonic epithelial cell line were used as controls. Various in vitro assays such as cell proliferation, wound healing and colony formation assays were performed to examine the miR-186-5p specific cellular effects. Western blots and immunohistochemistry analysis were performed to examine the modulation of FAM134B, PARP9 and KLF7 proteins expression.

RESULTS

Significant high expression of miR-186-5p was noted in cancer tissues (p< 0.001) and cell lines (p<0.05) when compared to control tissues and cells. The majority of the patients with colorectal cancer (88/126) had shown overexpression of miR-186-5p. This miR-186-5p overexpression was predominantly noted with in cancer with distant metastasis (p=0.001), lymphovascular permeation (p=0.037), microsatellite instability (MSI) stable (p=0.015), in distal colorectum (p=0.043) and with associated adenomas (p=0.047). Overexpression of miR-186-5p resulted in increased cell proliferation, colony formation, wound healing capacities and induced alteration of cell cycle kinetics in colon cancer cells. On the other hand, inhibition of endogenous miR-186-5p reduced the cancer growth properties. miR-186-5p overexpression reduced FAM134B expression significantly in the cancer cells (p<0.01). Also, FAM134B and miR-186-5p expressions are inversely correlated in colorectal cancer tissues and cells.

CONCLUSION

The miR-186-5p expression promotes colorectal cancer pathogenesis by regulating tumour suppressor FAM134B. Reduced cancer cells growth followed by inhibition of miR-186-5p highlights the potential of miR-186-5p inhibitor as a novel strategy for targeting colorectal cancer initiation and progression.

Effectiveness of Screening Modalities in Colorectal Cancer: A Network Meta-Analysis

The aim of the study was to evaluate on the effectiveness of screening modalities in the prevention of colorectal cancer (CRC) occurrence and deaths. General meta-analysis was performed to produce pooled estimates of the effect of CRC incidence and mortality using a search of PubMed, Web of Science, and the Cochrane Library for eligible studies from January 1992 to March 2016. A network meta-analysis was performed to synthetically compare the effectiveness of 5 frequently used screening modalities. A total of 44 studies with a focus on mortality from CRC using different screening methods were included. General meta-analysis showed that fecal immunohistochemical testing (FIT), flexible sigmoidoscopy (FS), colonoscopy, combination of fecal occult blood testing and FS screening respectively reduced CRC mortality by 59% (relative risk [RR], 0.41; 95% confidence interval [CI], 0.29-0.59), 33% (RR, 0.67; 95% CI, 0.58-0.78), 61% (RR, 0.39; 95% CI, 0.31-0.50), 38% (RR, 0.62; 95% CI, 0.42-0.91) compared with no screening, whereas guaiac fecal occult blood testing (gFOBT) reduced CRC-related mortality by 14% (RR, 0.86; 95% CI, 0.82-0.90). Subgroup analysis showed that summary estimates of reduction in distal CRC mortality and proximal CRC mortality were 26% (95% CI, 62%-89%) and 10% (95% CI, 83%-98%). A network meta-analysis revealed rank probability analysis in which the colonoscopy had a 94.6% probability of being the most effective examination to reduce CRC mortality. In addition, the network meta-analysis estimated odds ratio, which was a 79% reduction (95% CI, 0.09-0.60) in CRC mortality when screening with FIT was compared with annual or biennial gFOBT and colonoscopy was approximately 80% more effective than gFOBT for reducing CRC mortality (RR, 0.25; 95% CI, 0.13-0.54). Analysis of the effects of different screening methods showed that there was a significant reduction in the incidence of colon cancer, excluding gFOBT. This meta-analysis confirmed that gFOBT, FIT, FS, and colonoscopy were all effective in preventing CRC deaths and a major reduction in distal but not proximal CRC mortality was found. In addition, they were more effective in preventing CRC incidence in addition to gFOBT. The network meta-analysis suggests that colonoscopy is the most effective screening for preventing CRC deaths.

Validation of a Patient Satisfaction Scale in Patients Undergoing Bowel Preparation Prior to Colonoscopy

BACKGROUND

Colonoscopy is the most widely used test to screen for colorectal cancer but its use may be hindered by patients' inability to complete the bowel preparation. Patient-reported satisfaction with bowel-cleansing preparations has received little attention. We assessed the reliability and validity of a patient satisfaction survey used in two large, multicenter, randomized, assessor-blinded colonoscopy trials.

METHODS

Datasets from two pivotal trials were combined. Patients in both trials included men and women aged 18-80 years who were scheduled for an elective outpatient colonoscopy. Questions relevant to satisfaction with bowel preparation prior to colonoscopy were identified from the literature and incorporated into a 7-item survey administered to patients on the day of colonoscopy. Domain 1 of the satisfaction measure assessed difficulty using bowel-cleansing preparations, ability to consume preparations, acceptability of taste, and overall experience; questions regarding acceptance or refusal of future use of the same bowel preparation were asked in Domain 2. Responses from each item of Domain 1 were transformed on a scale ranging from 0 to 100 and summed as total satisfaction scores. Cronbach's alpha was used to measure reliability; validity was assessed by evaluating relationship between total satisfaction (Domain 1) and willingness to use preparation in the future (Domain 2).

RESULTS

Mean age of the 1211 trial participants was 56: 61 % female, 89.5 % Caucasian. Domain 1 had a Cronbach's alpha of 0.79, with higher satisfaction predicting higher future acceptability (p < 0.0001).

CONCLUSION

The patient-reported satisfaction measure of bowel-cleansing preparations possesses good validity and reliability.

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.

Ten-year incidence of colorectal cancer following a negative screening sigmoidoscopy: an update from the Colorectal Cancer Prevention (CoCaP) programme

OBJECTIVE

To examine the rates of colorectal cancer (CRC) following a negative screening sigmoidoscopy.

DESIGN

Cohort study.

SETTING

An integrated healthcare delivery organisation in California, USA.

PARTICIPANTS

72,483 men and women aged 50 years and above who had a negative screening sigmoidoscopy between 1994 and 1996. Those at elevated risk of CRC due to inflammatory bowel disease, prior polyps or CRC, or a strong family history of CRC were excluded.

MAIN OUTCOME MEASURES

Incidence rates of distal and proximal CRC. Standardised Incidence Ratios were used to compare annual incidence rates of distal and proximal CRC in the cohort to expected rates based on Surveillance, Epidemiology, and End Results data. Additionally, rate ratios (RR) and rate differences (RD) comparing the incidence rate of distal CRC in years 6+ postscreening with that in years 1-5 were calculated.

RESULTS

Incidence rates of distal CRC were lower than those in the San Francisco Bay area population at large during each of the first 10 years postsigmoidoscopy screening. However, the incidence of distal CRC rose steadily, from 3 per 100,000 in the first year of follow-up to 40 per 100,000 in the 10th year. During the second half of follow-up, the rate of distal CRC was twice as high as in the first half (RR 2 .08, 95% CI 1.38 to 3.16; RD 14 per 100,000 person-years, 95% CI 6 to 22).

CONCLUSIONS

Though still below population levels, the incidence of CRC during years 6-10 following a negative sigmoiodoscopy is appreciably higher than during the first 5 years.

Adherence to Competing Strategies for Colorectal Cancer Screening Over 3 Years

OBJECTIVES

We have shown that, in a randomized trial comparing adherence to different colorectal cancer (CRC) screening strategies, participants assigned to either fecal occult blood testing (FOBT) or given a choice between FOBT and colonoscopy had significantly higher adherence than those assigned to colonoscopy during the first year. However, how adherence to screening changes over time is unknown.

METHODS

In this trial, 997 participants were cluster randomized to one of the three screening strategies: (i) FOBT, (ii) colonoscopy, or (iii) a choice between FOBT and colonoscopy. Research assistants helped participants to complete testing only in the first year. Adherence to screening was defined as completion of three FOBT cards in each of 3 years after enrollment or completion of colonoscopy within the first year of enrollment. The primary outcome was adherence to assigned strategy over 3 years. Additional outcomes included identification of sociodemographic factors associated with adherence.

RESULTS

Participants assigned to annual FOBT completed screening at a significantly lower rate over 3 years (14%) than those assigned to colonoscopy (38%, P<0.001) or choice (42%, P<0.001); however, completion of any screening test fell precipitously, indicating the strong effect of patient navigation. In multivariable logistic regression analysis, being randomized to the choice or colonoscopy group, Chinese language, homosexuality, being married/partnered, and having a non-nurse practitioner primary care provider were independently associated with greater adherence to screening (P<0.01).

CONCLUSIONS

In a 3-year follow-up of a randomized trial comparing competing CRC screening strategies, participants offered a choice between FOBT and colonoscopy continued to have relatively high adherence, whereas adherence in the FOBT group fell significantly below that of the choice and colonoscopy groups. Patient navigation is crucial to achieving adherence to CRC screening, and FOBT is especially vulnerable because of the need for annual testing.

Observational methods to assess the effectiveness of screening colonoscopy in reducing right colon cancer mortality risk: SCOLAR

AIMS

Screening colonoscopy's effectiveness in reducing risk of death from right colon cancers remains unclear. Methodological challenges of existing observational studies addressing this issue motivated the design of 'Effectiveness of Screening for Colorectal Cancer in Average-Risk Adults (SCOLAR)'.

METHODS

SCOLAR is a nested case-control study based on two large integrated health systems. This affords access to a large, well-defined historical cohort linked to integrated data on cancer outcomes, patient eligibility, test indications and important confounders.

RESULTS

We found electronic data adequate for excluding ineligible patients (except family history), but not the detailed information needed for test indication assignment.

CONCLUSION

The lessons of SCOLAR's design and implementation may be useful for future studies seeking to evaluate the effectiveness of screening tests in community settings.

Cost-effectiveness simulation and analysis of colorectal cancer screening in Hong Kong Chinese population: comparison amongst colonoscopy, guaiac and immunologic fecal occult blood testing

Background

The aim of this study was to evaluate the cost-effectiveness of CRC screening strategies from the healthcare service provider perspective based on Chinese population.

Methods

A Markov model was constructed to compare the cost-effectiveness of recommended screening strategies including annual/biennial guaiac fecal occult blood testing (G-FOBT), annual/biennial immunologic FOBT (I-FOBT), and colonoscopy every 10 years in Chinese aged 50 year over a 25-year period. External validity of model was tested against data retrieved from published randomized controlled trials of G-FOBT. Recourse use data collected from Chinese subjects among staging of colorectal neoplasm were combined with published unit cost data ($USD in 2009 price values) to estimate a stage-specific cost per patient. Quality-adjusted life-years (QALYs) were quantified based on the stage duration and SF-6D preference-based value of each stage. The cost-effectiveness outcome was the incremental cost-effectiveness ratio (ICER) represented by costs per life-years (LY) and costs per QALYs gained.

Results

In base-case scenario, the non-dominated strategies were annual and biennial I-FOBT. Compared with no screening, the ICER presented $20,542/LYs and $3155/QALYs gained for annual I-FOBT, and $19,838/LYs gained and $2976/QALYs gained for biennial I-FOBT. The optimal screening strategy was annual I-FOBT that attained the highest ICER at the threshold of $50,000 per LYs or QALYs gained.

Conclusion

The Markov model informed the health policymakers that I-FOBT every year may be the most effective and cost-effective CRC screening strategy among recommended screening strategies, depending on the willingness-to-pay of mass screening for Chinese population.

Trial registration

ClinicalTrials.gov Identifier NCT02038283

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1730-y) contains supplementary material, which is available to authorized users.

Protective association of colonoscopy against proximal and distal colon cancer and patterns in interval cancer

BACKGROUND

The protective effect of colonoscopy against proximal colorectal cancer is variable and depends on the detection and complete removal of precancerous polyps.

OBJECTIVE

To estimate the efficacy of colonoscopy in a medical center with open-access screening colonoscopy since 1998.

DESIGN

Nested case-control study with incidence density sampling.

SETTING

University-affiliated Veterans Affairs Medical Center.

PATIENTS

Colorectal cancer (CRC) cases and control subjects selected from screening age patients matched by age, gender, and date of first primary care visit.

MAIN OUTCOME MEASUREMENT

Colonoscopy preceding the CRC diagnosis date.

RESULTS

A total of 20.2% of CRC cases had a colonoscopy in the preceding 10 years compared with 49.0% of control subjects (adjusted odds ratio [aOR], 0.20; 95% confidence interval [CI], 0.11-0.34). Colonoscopy was strongly associated with decreased odds of both distal CRC (aOR, 0.16; 95% CI, 0.07-0.34) and proximal CRC (aOR, 0.26; 95% CI, 0.11-0.58). The fraction of cases attributed to interval cancers was 10.5%. Missed lesions predominantly localized to the cecum and rectum, and recurrent lesions clustered in the hepatic flexure. Cecal intubation rate was 93% (98% in adequately prepped patients), and the adenoma detection rate was 45.2% in the control group.

LIMITATIONS

Single-center, retrospective case-control design.

CONCLUSION

In an open access colonoscopy program characterized by a high cecal intubation rate and adenoma detection rate, colonoscopy was strongly associated with reduced odds of both distal and proximal CRC. Among interval cancers, missed lesions clustered in the cecum and rectum and recurrent lesions in the hepatic flexure.

Breast Cancer Survivorship Care: Targeting a Colorectal Cancer Education Intervention

Breast cancer survivors are at risk of developing a second primary cancer. Colorectal cancer (CRC) is one of the leading second primary cancers, and it is often preventable. We developed a multi-component educational tool to inform and encourage women breast cancer survivors to engage in CRC screening. To assess the strengths and weakness of the tool and to improve the relevancy to the target audience, we convened four focus groups of women breast cancer survivors in Missouri. We also assessed the potential impact of the tool on the knowledge, attitudes, and beliefs regarding CRC and collected information on the barriers to CRC screening through pre- and post-focus groups' questionnaires. A total of 43 women breast cancer survivors participated and provided very valuable suggestions on design and content to update the tool. Through the process and comparing pre- and post-focus group assessments, a significantly higher proportion of breast cancer survivors strongly agreed or agreed that CRC is preventable (78.6% vs. 96.9%, p = 0.02) and became aware that they were at a slightly increased risk for CRC (18.6% vs. 51.7%, p = 0.003). The most cited barrier was the complexity of preparation for colonoscopy.

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.

Disgusted, embarrassed, annoyed: affective associations relate to uptake of colonoscopy screening

BACKGROUND

Uptake of colorectal cancer screening is lower than desired. Screening decision making research has traditionally focused on benefits and barriers to screening. This study examines the relation of affective associations with screening (feelings and emotions associated with screening) to colonoscopy screening uptake.

METHODS

Participants were 103 African American community adults. Participants completed a structured interview assessing perceived benefits of and barriers to colonoscopy screening, affective associations with colonoscopy, colonoscopy screening behavior, and intentions for future screening.

RESULTS

Higher positive and lower negative affective associations with screening were both significant predictors of colonoscopy uptake. Affective associations fully mediated the relation of perceived benefits and barriers to screening uptake. Affective associations were associated with intentions for future screening.

CONCLUSIONS

Incorporation of affective associations into models of screening decision making and intervention approaches to address screening compliance has utility for advancing our understanding of screening adherence as well as increasing screening rates.

Comparing the effectiveness of competing tests for reducing colorectal cancer mortality: a network meta-analysis

BACKGROUND

Comparative effectiveness data pertaining to competing colorectal cancer (CRC) screening tests do not exist but are necessary to guide clinical decision making and policy.

OBJECTIVE

To perform a comparative synthesis of clinical outcomes studies evaluating the effects of competing tests on CRC-related mortality.

DESIGN

Traditional and network meta-analyses. Two reviewers identified studies evaluating the effect of guaiac-based fecal occult blood testing (gFOBT), flexible sigmoidoscopy (FS), or colonoscopy on CRC-related mortality.

INTERVENTIONS

gFOBT, FS, colonoscopy.

MAIN OUTCOME MEASUREMENTS

Traditional meta-analysis was performed to produce pooled estimates of the effect of each modality on CRC mortality. Bayesian network meta-analysis (NMA) was performed to indirectly compare the effectiveness of screening modalities. Multiple sensitivity analyses were performed.

RESULTS

Traditional meta-analysis revealed that, compared with no intervention, colonoscopy reduced CRC-related mortality by 57% (relative risk [RR] 0.43; 95% confidence interval [CI], 0.33-0.58), whereas FS reduced CRC-related mortality by 40% (RR 0.60; 95% CI, 0.45-0.78), and gFOBT reduced CRC-related mortality by 18% (RR 0.82; 95% CI, 0.76-0.88). NMA demonstrated nonsignificant trends favoring colonoscopy over FS (RR 0.71; 95% CI, 0.45-1.11) and FS over gFOBT (RR 0.74; 95% CI, 0.51-1.09) for reducing CRC-related deaths. NMA-based simulations, however, revealed that colonoscopy has a 94% probability of being the most effective test for reducing CRC mortality and a 99% probability of being most effective when the analysis is restricted to screening studies.

LIMITATIONS

Randomized trials and observational studies were combined within the same analysis.

CONCLUSION

Clinical outcomes studies demonstrate that gFOBT, FS, and colonoscopy are all effective in reducing CRC-related mortality. Network meta-analysis suggests that colonoscopy is the most effective test.

Colorectal cancer deaths attributable to nonuse of screening in the United States

PURPOSE

Screening is a major contributor to colorectal cancer (CRC) mortality reductions in the United States but is underused. We estimated the fraction of CRC deaths attributable to nonuse of screening to demonstrate the potential benefits from targeted interventions.

METHODS

The established microsimulation screening analysis colon model was used to estimate the population attributable fraction (PAF) in people aged ≥50 years. The model incorporates long-term patterns and effects of screening by age and type of screening test. PAF for 2010 was estimated using currently available data on screening uptake. PAF was also projected assuming constant future screening rates to incorporate lagged effects from past increases in screening uptake. We also computed PAF using Levin's formula to gauge how this simpler approach differs from the model-based approach.

RESULTS

There were an estimated 51,500 CRC deaths in 2010, about 63% (N ∼ 32,200) of which were attributable to nonscreening. The PAF decreases slightly to 58% in 2020. Levin's approach yielded a considerably more conservative PAF of 46% (N ∼ 23,600) for 2010.

CONCLUSIONS

Most of the current United States CRC deaths are attributable to nonscreening. This underscores the potential benefits of increasing screening uptake in the population. Traditional methods of estimating PAF underestimated screening effects compared with model-based approaches.

Blood-based testing for colorectal cancer screening

Colorectal cancer (CRC) is the third most common non-skin cancer diagnosed in men and women in the USA and worldwide. While it has been clearly established that screening for CRC, using a variety of methods, is cost effective and has a significant impact on overall survival, screening rates have proven to be sub-optimal. It has been long conjectured that a simple blood-based test, with a specimen drawn at a routine doctor's office visit, would encourage those individuals who have refused or ignored screening recommendations to undergo screening. This article reviews the currently available blood-based screening tests for CRC, including the ColonSentry™ messenger RNA (mRNA) expression panel and the SEPT9 methylated DNA test, and explores newer biomarkers that are near clinical implementation. Also discussed are additional applications for blood-based CRC testing, such as assessing prognosis, disease surveillance, and expansion of screening tests to high-risk populations, such as the estimated 1.4 million individuals in the USA with inflammatory bowel disease.

Impact of sigmoidoscopy and colonoscopy on colorectal cancer incidence and mortality: an evidence-based review of published prospective and retrospective studies

Screening for colorectal cancer (CRC) using sigmoidoscopy or colonoscopy is now common in many developed countries. This concise, evidence-based review looks at the impact of sigmoidoscopy or colonoscopy screening on CRC incidence, CRC mortality and overall mortality. Data from controlled retrospective and prospective (observational or randomized) studies have generally shown that sigmoidoscopy and colonoscopy, whether for diagnostic, screening or surveillance purposes, are associated with a significant reduction in CRC incidence and CRC mortality. The data on their impact on overall mortality is much more limited, with most studies unable to report a reduction in overall mortality. The results of three meta-analyses have confirmed these conclusions. As expected, sigmoidoscopy has a predominant effect on left-sided CRC, although some studies have shown modest effects on right-sided colon cancer as well. Most studies on colonoscopy have demonstrated that the protective effect applies to both right and left-sided cancer, although the protection seemed better on the left side. Despite the introduction of other screening and diagnostic modalities for the colon, such as computed tomography colonography and colonic capsule endoscopy, lower endoscopy will continue to be an important mode of screening for CRC and evaluating the colon.

Using computational modeling to assess the impact of clinical decision support on cancer screening improvement strategies within the community health centers

Our conceptual model demonstrates our goal to investigate the impact of clinical decision support (CDS) utilization on cancer screening improvement strategies in the community health care (CHC) setting. We employed a dual modeling technique using both statistical and computational modeling to evaluate impact. Our statistical model used the Spearman's Rho test to evaluate the strength of relationship between our proximal outcome measures (CDS utilization) against our distal outcome measure (provider self-reported cancer screening improvement). Our computational model relied on network evolution theory and made use of a tool called Construct-TM to model the use of CDS measured by the rate of organizational learning. We employed the use of previously collected survey data from community health centers Cancer Health Disparities Collaborative (HDCC). Our intent is to demonstrate the added valued gained by using a computational modeling tool in conjunction with a statistical analysis when evaluating the impact a health information technology, in the form of CDS, on health care quality process outcomes such as facility-level screening improvement. Significant simulated disparities in organizational learning over time were observed between community health centers beginning the simulation with high and low clinical decision support capability.

Magnetic imaging-assisted colonoscopy vs conventional colonoscopy: A randomized controlled trial

AIM: To compare magnetic imaging-assisted colonoscopy (MIC) with conventional colonoscopy (CC).

METHODS: Magnetic imaging technology provides a computer-generated image of the shape and position of the colonoscope onto a monitor to give visual guidance to the endoscopist. It is designed to improve colonoscopy performance and tolerability for patients by enabling visualization of loop formation and endoscope position. Recently, a new version of MIC technology was developed for which there are limited data.To evaluate this latest generation of MIC among experienced rather than inexperienced or trainee endoscopists, a prospective randomized trial was performed using only gastroenterologists with therapeutic endoscopy training. Consecutive patients undergoing elective outpatient colonoscopy were randomized to MIC or CC, with patients blinded to their group assignment. Endoscopic procedural metrics and quantities of conscious sedation medications were recorded during the procedures. The procedure was classified as “usual” or “difficult” by the endoscopist at the conclusion of each case based on the need for adjunctive maneuvers to facilitate endoscope advancement. After more than one hour post-procedure, patients completed a 10 cm visual analogue pain scale to reflect the degree of discomfort experienced during their colonoscopy. The primary outcome was patient comfort expressed by the visual analogue pain score. Secondary outcomes consisted of endoscopic procedural metrics as well as a sedation score derived from standardized dose increments of the conscious sedation medications.

RESULTS: Two hundred fifty-three patients were randomized and underwent MIC or CC between September 2011 and October 2012. The groups were similar in terms of the indications for colonoscopy and patient characteristics. There were no differences in cecal intubation rates (100% vs 99%), insertion distance-to-cecum (82 cm vs 83 cm), time-to-cecum (6.5 min vs 7.2 min), or polyp detection rate (47% vs 52%) between the MIC and CC groups. The primary outcome of mean pain score (1.0 vs 0.9 out of 10, P = 0.41) did not differ between MIC and CC groups, nor did the mean sedation score (8.2 vs 8.5, P = 0.34). Within the subgroup of cases considered more challenging or difficult, time-to-cecum was significantly faster with MIC compared to CC, 10.1 min vs 13.4 min respectively (P = 0.01). Sensitivity analyses confirmed a similar pattern of overall findings when each endoscopist was considered separately, demonstrating that the mean results for the entire group were not unduly influenced by outlier results from any one endoscopist.

CONCLUSION: Although the latest version of MIC resulted in faster times-to-cecum within a subgroup of more challenging cases, overall it was no better than CC in terms of patient comfort, sedation requirements and endoscopic procedural metrics, when performed in experienced hands.

Colonoscopy reduced distal colorectal cancer risk and excess cancer risk associated with family history

PURPOSE

Colonoscopy efficacy at preventing proximal colorectal cancer (CRC) is questioned, and little is known about efficacy in high-risk versus medium-risk populations. We investigated the relationship between colonoscopy screening, family history of colorectal cancer (FHCC), and CRC risk by site.

METHODS

Among 92,078 women of the E3N prospective cohort, 692 CRCs have been diagnosed after a median follow-up of 15.4 years. Cox proportional hazard models estimated adjusted hazards ratios according to subsites of cancer and FHCC.

RESULTS

A personal history of colonoscopy (PHC; n = 37,470) was associated with decreased rectal and distal colon cancer risks (hazard ratio (HR) = 0.57; 95% Confidence Interval (CI) = 0.42-0.78 and HR = 0.37; 95% CI = 0.26-0.52, respectively), but not proximal colon cancer risk (HR = 0.87; 95% CI = 0.64-1.18). In women with no prior colonoscopy, those with FHCC had a 80% higher CRC risk than those without FHCC. In women with previous colonoscopy, CRC risk was similar in women with and without FHCC (p for interaction = 0.04).

CONCLUSIONS

Results showed colonoscopy ability to prevent distal cancers, but not proximal cancers in women. Colonoscopy screening also reduced the excess risk of women with FHCC to that of women with no FHCC.

Screening strategies for colorectal cancer in asymptomatic adults

This article provides an update for the primary care community on the evidence and recommendations for colorectal cancer screening in the adult population without symptoms at average and increased risk, excluding patients with high-risk genetic syndromes. The current and possible new screening strategies are reviewed, along with clinical wisdom related to the implementation of each method.

ACR Appropriateness Criteria colorectal cancer screening

Colorectal cancer is the third leading cause of cancer deaths in the United States. Most colorectal cancers can be prevented by detecting and removing the precursor adenomatous polyp. Individual risk factors for the development of colorectal cancer will influence the particular choice of screening tool. CT colonography (CTC) is the primary imaging test for colorectal cancer screening in average-risk individuals, whereas the double-contrast barium enema (DCBE) is now considered to be a test that may be appropriate, particularly in settings where CTC is unavailable. Single-contrast barium enema has a lower performance profile and is indicated for screening only when CTC and DCBE are not available. CTC is also the preferred test for colon evaluation following an incomplete colonoscopy. Imaging tests including CTC and DCBE are not indicated for colorectal cancer screening in high-risk patients with polyposis syndromes or inflammatory bowel disease. This paper presents the updated colorectal cancer imaging test ratings and is the result of evidence-based consensus by the ACR Appropriateness Criteria Expert Panel on Gastrointestinal Imaging. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

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.

Patient factors that affect quality of colonoscopy preparation

BACKGROUND & AIMS

Optimal colonoscopy preparation requires patients to adhere to written instructions and be activated to complete the task. Among patients with chronic disease, health literacy and patient activation have been associated with outcome, but these factors have not been studied for colonoscopy. We examined the association between health literacy, patient activation, and quality of bowel preparation.

METHODS

We analyzed outpatient colonoscopy results from 462 adults, 55-74 years old (mean, 62 ± 6 years), who previously completed extensive neurocognitive assessments as part of a prospective study (Health Literacy and Cognitive Function in Older Adults). We collected information on cecal intubation, polyp detection, bowel preparation quality, and histopathology.

RESULTS

One-third of the patients (n = 134) had suboptimal quality of bowel preparation; 15% (n = 62) had fair quality, and 17% (n = 72) had poor quality. Limited health literacy was associated with a lower level of education (P < .001), diabetes (P < .001), and a higher number of chronic conditions (P < .001), but not quality of colonoscopy preparation. No baseline characteristics were associated with patient activation. In multivariable analysis, after adjusting for demographics and clinical characteristics, diabetes (odds ratio [OR], 2.45; 95% confidence interval [CI], 1.14-5.25) and patient activation (OR, 2.12; 95% CI, 1.30-3.45) were independent predictors of suboptimal bowel preparation quality, but limited health literacy was not (OR, 0.76; 95% CI, 0.38-1.52).

CONCLUSIONS

We investigated the relationship between health literacy, patient activation, and colonoscopy preparation quality. Lower patient activation was an independent predictor of suboptimal bowel preparation quality. Interventions to improve colonoscopy preparation quality should consider the importance of patient activation within their design.

Reduced risk of colorectal cancer up to 10 years after screening, surveillance, or diagnostic colonoscopy

BACKGROUND & AIMS

Data from randomized controlled trials on the effects of screening colonoscopies on colorectal cancer (CRC) incidence and mortality are not available. Observational studies have suggested that colonoscopies strongly reduce the risk of CRC, but there is little specific evidence on the effects of screening colonoscopies.

METHODS

We performed a population-based case-control study of 3148 patients with a first diagnosis of CRC (cases) and 3274 subjects without CRC (controls) from the Rhine-Neckar region of Germany from 2003 to 2010. Detailed information on previous colonoscopy and potential confounding factors was collected by standardized personal interviews. Self-reported information on colonoscopies and their indications was validated by medical records. We used multiple logistic regression to assess the association between colonoscopy conducted for specific indications within the past 10 years and risk of CRC.

RESULTS

A history of colonoscopy was associated with a reduced subsequent risk of CRC, independently of the indication for the examination. However, somewhat stronger associations were found for examinations with screening indications (adjusted odds ratio [OR] 0.09, 95% confidence interval [CI] 0.07-0.13) than for examinations with diagnostic indications, such as positive fecal occult blood test result (OR, 0.33; 95% CI, 0.19-0.57), surveillance after a preceding colonoscopy (OR, 0.33; 95% CI, 0.24-0.45), rectal bleeding (OR, 0.28; 95% CI, 0.20-0.40), abdominal symptoms (OR, 0.15; 95% CI, 0.10-0.21), or other (OR, 0.21; 95% CI, 0.14-0.30). Colonoscopy was also associated with a reduced risk of cancer in the right colon, regardless of the indication, although to a smaller extent than for other areas of the colon (OR for screening colonoscopy, 0.22; 95% CI, 0.14-0.33).

CONCLUSIONS

In a population-based case-control study, the risk of CRC was strongly reduced up to 10 years after colonoscopy for any indication. Risk was particularly low after screening colonoscopy, even for cancer in the right colon.

Public health and cooperative group partnership: a colorectal cancer intervention

OBJECTIVES

To describe the development of a multi-component colorectal cancer educational tool for female breast cancer survivors through a cooperative group and public health partnership.

DATA SOURCES

PubMed, World Wide Web, guidelines from professional organizations, surveys and focus groups with breast cancer survivors.

CONCLUSION

Collaboration is at the core of cooperative group and public health research. This partnership led to the development of a colorectal cancer educational tool for breast cancer survivors. Focus groups revealed that female breast cancer survivors were receptive to education on colorectal cancer screening.

IMPLICATIONS FOR NURSING PRACTICE

Nurses are instrumental in research collaborations between cooperative groups and public health. The colorectal educational intervention for breast cancer survivors serves as an exemplar of partnerships leading to innovative research planning and implementation outcomes.

Barriers to screening colonoscopy in an urban population: a study to help focus further efforts to attain full compliance

BACKGROUND

Awareness of colorectal cancer and decision for colorectal cancer screening is influenced by multiple factors including ethnicity, level of education, and adherence to regular medical follow up.

OBJECTIVE

Our survey aimed at assessing barriers to colorectal cancer screening among urban population.

DESIGN

This study is a survey of the general population.

SETTING

This study was made at a local community in the downtown area of a metropolitan city.

PATIENTS/SUBJECTS

The study population for this survey included 2000 non-institutionalized residents from local community of Brooklyn downtown area of City of Brooklyn, NY, USA. All participants were 50 years or older.

INTERVENTION

No intervention was done.

MAIN OUTCOME MEASUREMENT

The survey questionnaire collected information about demographic, socioeconomic level, awareness of various cancers and their screening methods, and awareness of screening colonoscopy.

RESULTS

Colonoscopy was identified as the best screening test by 31 % of the subjects. Pain and discomfort was the major reason for not having a colonoscopy. The fear of a complication declined significantly after the first colonoscopy but fear of pain and discomfort increased. Difficulty with bowel preparation before a colonoscopy was a significant problem; it discouraged significant number of participants from having another colonoscopy.

LIMITATION

This study is limited by its small sample size.

CONCLUSION

Physician/family and peer influence seems important but influencing only a minority of subjects. Fear of complications should be allayed using accurate statistical information. Pain should be significantly diminished and/or eliminated during colonoscopy. Future research should focus to minimize complexity and discomfort associated with bowel preparation.

Colonoscopy and colorectal cancer incidence and mortality

There is substantial indirect evidence for the effectiveness of colonoscopy in reducing colorectal cancer incidence and mortality. However, several recent studies have raised questions on the magnitude of effect for right-sided colorectal cancers. Well-documented variation in outcomes when colonoscopy is performed by different groups of endoscopists suggests that the recent emphasis on the quality of the procedures should lead to improved outcomes after colonoscopy including reduction in incidence and mortality due to right-sided colorectal cancers.

Review article: historic changes of Helicobacter pylori-associated diseases

BACKGROUND

The long-term time trends of multiple gastrointestinal diseases are characterised by a striking rise and fall. These temporal changes provide important clues about disease aetiology.

AIM

To highlight the importance of Helicobacter pylori infection in shaping the temporal trends of many common gastrointestinal diseases.

METHODS

Literature review of the time trends associated with common digestive diseases.

RESULTS

The general trends of gastric ulcer, duodenal ulcer, gastric cancer, colon cancer, rectum cancer have all been shaped by a similar underlying birth-cohort phenomenon. Mortality associated with these diagnoses increased in all generations born during the nineteenth century. It peaked among generations born shortly before the turn of the century and then decreased in all subsequent generations born throughout the twentieth century. These patterns can be observed in the incidence, hospitalisation and mortality data from many different countries. They reflect similar rising and falling trends of H. pylori infection in the general population. Diseases that are inversely associated with H. pylori, such as reflux disease, erosive oesophagitis, Barrett's oesophagus, and oesophageal adenocarcinoma, have seen a striking rise during the recent decline of H. pylori infection.

CONCLUSION

The temporal variations of H. pylori infection have affected the occurrence of gastroenterology's most common disorders.

Natural history of colorectal adenomas: birth cohort analysis among 3.6 million participants of screening colonoscopy

BACKGROUND

Most colorectal cancers (CRC) develop from adenomas. Knowledge of the natural history of colorectal adenomas, which is not directly observable for ethical reasons, is crucial for designing cost-effective CRC screening strategies.

METHODS

We derived transition rates from carriage of nonadvanced adenoma to carriage of advanced adenoma to carriage of CRC by sex and age in birth cohort analyses among 3,593,420 participants in the German screening colonoscopy program in 2003-2010.

RESULTS

Transition rates from advanced adenoma to CRC carriage were similar in men and women, but monotonically and significantly increased with age. Estimated annual transition percentages [(95% confidence interval (CI)] in age groups 55-59, 60-64, 65-69, 70-74, and 75-79 years were 2.6 (2.4-2.9), 3.1 (2.8-3.3), 3.8 (3.5-4.1), 5.1 (4.8-5.5), and 5.2 (4.6-5.8) among men, and 2.5 (2.2-2.7), 2.7 (2.4-3.0), 3.8 (3.5-4.1), 5.0 (4.5-5.4), and 5.6 (4.9-6.3) among women. Estimated annual transitions from carriage of nonadvanced to carriage of advanced adenoma were in a narrow range from 3.6% to 4.7% for all age and sex groups.

CONCLUSIONS

Despite low annual transition rates, cumulative transition rates from advanced adenoma to CRC carriage are expected to exceed by 60%, 50%, and 40% for age intervals 55-80, 65-80, and 70-80 years, respectively, in both sexes. Cumulative transition rates from nonadvanced adenoma to CRC carriage are expected to be close to 30% for age interval 55-80 years, but less than 2% for age interval 75-80 years.

IMPACT

Our results enhance the empirical basis for modeling CRC screening strategies.

Colorectal cancers occurring after colonoscopy with polyp detection: sites of polyps and sites of cancers

Colonoscopy with detection and removal of neoplasms strongly reduces risk of colorectal cancer (CRC). Nevertheless, CRCs occur after colonoscopic polypectomy. We assessed agreement beyond chance of location of polyps detected at colonoscopy and of subsequent CRCs to estimate the share of cancers that might be due to field effects or neoplasm recrudescence. In a population-based case-control study conducted in Germany (3,148 cases), detailed history and results of colonoscopies conducted within 10 years before cancer diagnosis were obtained by interview and from medical records. We determined the observed proportion of cancers for which a polyp had been detected at the same colorectal subsite at the preceding colonoscopy and compared it to the proportion expected by chance. A total of 155 cases with physician validated polyp detection at the preceding colonoscopy were identified. Among 148 cases with cancer restricted to a single subsite, 43 (29.1%) had a polyp detected in the same colorectal subsite at the preceding colonoscopy. Agreement of location of cancer occurrence and preceding polyp detection would have been expected by chance for 27 cases, and agreement beyond chance was estimated to account for 16 cases (10.8%, 95% confidence interval 2.7%-19.3%). Our study suggests that less than one of nine CRCs occurring within 10 years after colonoscopy with polyp detection may be due to field effects or polyp recrudescence.