Cost-effectiveness of colonoscopy in screening for colorectal cancer

Investigation of the relationship between colonoscopy insertion difficulty factors and endoscope shape using an endoscopic position detection unit

In this study, we investigated the relationship between the cecal intubation time (CIT) and the form and method used for passing through the sigmoid/descending colon junction (SDJ) and the hepatic flexure using an endoscopic position detection unit (UPD), with reference to various factors [age, sex, body mass index (BMI), history of abdominal and pelvic surgery, and diverticulum]. A total of 152 patients underwent colonoscopy with UPD. The mean age was 66.9 ± 12.4 years, and the male to female ratio was 3.6:1. The average CIT time was 14.3 ± 8.2 min. Age, number of experienced endoscopies, history of abdominal and pelvic surgery, BMI, and diverticulum were associated with prolonged CIT; SDJ passage pattern was straight: 8.6 ± 5.0, alpha loop: 11.8 ± 5.6, puzzle ring-like loop: 20.2 ± 5.0, reverse alpha loop: 22.4 ± 9.7, and other loop: 24.7 ± 10.5. The hepatic flexure passing method was in the following order: right rotation maneuver: 12.6 ± 6.6, push maneuver: 15.1 ± 5.9, and right rotation with positional change maneuver: 20.5 ± 7.2. In conclusion, colonoscopy with UPD revealed an association between CIT and SDJ passage pattern and hepatic flexure passing method.

Colorectal cancer screening: A review of current knowledge and progress in research

Colorectal cancer (CRC) is one of the most prevalent malignancies worldwide, being the third most commonly diagnosed malignancy and the second leading cause of cancer-related deaths globally. Despite the progress in screening, early diagnosis, and treatment, approximately 20%-25% of CRC patients still present with metastatic disease at the time of their initial diagnosis. Furthermore, the burden of disease is still expected to increase, especially in individuals younger than 50 years old, among whom early-onset CRC incidence has been increasing. Screening and early detection are pivotal to improve CRC-related outcomes. It is well established that CRC screening not only reduces incidence, but also decreases deaths from CRC. Diverse screening strategies have proven effective in decreasing both CRC incidence and mortality, though variations in efficacy have been reported across the literature. However, uncertainties persist regarding the optimal screening method, age intervals and periodicity. Moreover, adherence to CRC screening remains globally low. In recent years, emerging technologies, notably artificial intelligence, and non-invasive biomarkers, have been developed to overcome these barriers. However, controversy exists over the actual impact of some of the new discoveries on CRC-related outcomes and how to effectively integrate them into daily practice. In this review, we aim to cover the current evidence surrounding CRC screening. We will further critically assess novel approaches under investigation, in an effort to differentiate promising innovations from mere novelties.

Projected Colorectal Cancer Incidence and Mortality Based on Observed Adherence to Colonoscopy and Sequential Stool-Based Screening

INTRODUCTION

Modeling supporting recommendations for colonoscopy and stool-based colorectal cancer (CRC) screening tests assumes 100% sequential participant adherence. The impact of observed adherence on the long-term effectiveness of screening is unknown. We evaluated the effectiveness of a program of screening colonoscopy every 10 years vs annual high-sensitivity guaiac-based fecal occult blood testing (HSgFOBT) using observed sequential adherence data.

METHODS

The MIcrosimulation SCreening ANalysis (MISCAN) model used observed sequential screening adherence, HSgFOBT positivity, and diagnostic colonoscopy adherence in HSgFOBT-positive individuals from the National Colonoscopy Study (single-screening colonoscopy vs ≥4 HSgFOBT sequential rounds). We compared CRC incidence and mortality over 15 years with no screening or 10 yearly screening colonoscopy vs annual HSgFOBT with 100% and differential observed adherence from the trial.

RESULTS

Without screening, simulated incidence and mortality over 15 years were 20.9 (95% probability interval 15.8-26.9) and 6.9 (5.0-9.2) per 1,000 participants, respectively. In the case of 100% adherence, only screening colonoscopy was predicted to result in lower incidence; however, both tests lowered simulated mortality to a similar level (2.1 [1.6-2.9] for screening colonoscopy and 2.5 [1.8-3.4] for HSgFOBT). Observed adherence for screening colonoscopy (83.6%) was higher than observed sequential HSgFOBT adherence (73.1% first round; 49.1% by round 4), resulting in lower simulated incidence and mortality for screening colonoscopy (14.4 [10.8-18.5] and 2.9 [2.1-3.9], respectively) than HSgFOBT (20.8 [15.8-28.1] and 3.9 [2.9-5.4], respectively), despite a 91% adherence to diagnostic colonoscopy with FOBT positivity. The relative risk of CRC mortality for screening colonoscopy vs HSgFOBT was 0.75 (95% probability interval 0.68-0.80). Findings were similar in sensitivity analyses with alternative assumptions for repeat colonoscopy, test performance, risk, age, and projection horizon.

DISCUSSION

Where sequential adherence to stool-based screening is suboptimal and colonoscopy is accessible and acceptable-as observed in the national colonoscopy study, microsimulation, comparative effectiveness, screening recommendations.

Growth rates and histopathological outcomes of small (6-9 mm) colorectal polyps based on CT colonography surveillance and endoscopic removal

BACKGROUND AND AIMS

The natural history of small polyps is not well established and rests on limited evidence from barium enema studies decades ago. Patients with one or two small polyps (6-9 mm) at screening CT colonography (CTC) are offered CTC surveillance at 3 years but may elect immediate colonoscopy. This practice allows direct observation of the growth of subcentimetre polyps, with histopathological correlation in patients undergoing subsequent polypectomy.

DESIGN

Of 11 165 asymptomatic patients screened by CTC over a period of 16.4 years, 1067 had one or two 6-9 mm polyps detected (with no polyps ≥10 mm). Of these, 314 (mean age, 57.4 years; M:F, 141:173; 375 total polyps) elected immediate colonoscopic polypectomy, and 382 (mean age 57.0 years; M:F, 217:165; 481 total polyps) elected CTC surveillance over a mean of 4.7 years. Volumetric polyp growth was analysed, with histopathological correlation for resected polyps. Polyp growth and regression were defined as volume change of ±20% per year, with rapid growth defined as +100% per year (annual volume doubling). Regression analysis was performed to evaluate predictors of advanced histology, defined as the presence of cancer, high-grade dysplasia (HGD) or villous components.

RESULTS

Of the 314 patients who underwent immediate polypectomy, 67.8% (213/314) harboured adenomas, 2.2% (7/314) with advanced histology; no polyps contained cancer or HGD. Of 382 patients who underwent CTC surveillance, 24.9% (95/382) had polyps that grew, while 62.0% (237/382) remained stable and 13.1% (50/382) regressed in size. Of the 58.6% (224/382) CTC surveillance patients who ultimately underwent colonoscopic resection, 87.1% (195/224) harboured adenomas, 12.9% (29/224) with advanced histology. Of CTC surveillance patients with growing polyps who underwent resection, 23.2% (19/82) harboured advanced histology vs 7.0% (10/142) with stable or regressing polyps (OR: 4.0; p<0.001), with even greater risk of advanced histology in those with rapid growth (63.6%, 14/22, OR: 25.4; p<0.001). Polyp growth, but not patient age/sex or polyp morphology/location were significant predictors of advanced histology.

CONCLUSION

Small 6-9 mm polyps present overall low risk to patients, with polyp growth strongly associated with higher risk lesions. Most patients (75%) with small 6-9 mm polyps will see polyp stability or regression, with advanced histology seen in only 7%. The minority of patients (25%) with small polyps that do grow have a 3-fold increased risk of advanced histology.

The effectiveness of walking exercise on the bowel preparation before colonoscopy: a single blind randomized clinical trial study

BACKGROUND AND AIM

Bowel preparation is a crucial factor affecting the diagnostic accuracy of colonoscopy, and few randomized control trials evaluated enhancement in bowel preparation. In this study, we aimed to evaluate the effectiveness of walking exercises on bowel preparation before a colonoscopy procedure.

METHODS

The present study is a single-blind randomized controlled trial involving 262 patients scheduled for colonoscopy procedures. These patients were randomly assigned to two groups: an intervention group (n = 131) and a control group (n = 131). In the intervention group, participants followed a predetermined plan that included the consumption of specific liquids and foods, bisacodyl pills, polyethylene glycol powder, and a regimen of walking exercises in preparation for their colonoscopy. Conversely, individuals in the control group followed the same regimen but were not instructed to engage in walking exercises. On the day of the colonoscopy, both groups were assessed for their level of physical activity using a foot counter. Additionally, an experienced gastroenterologist evaluated and compared the bowel preparation between the two groups using the Boston Bowel Preparation Scale (BBPS).

RESULTS

The number of footsteps recorded in the two groups exhibited a significant difference (P < 0.001). Although there was no statistically significant difference between the intervention and control groups in terms of mean BBPS scores (6.26 ± 1.9 vs. 6.29 ± 1.9, P = 0.416), individuals who took more than 6900 steps had significantly higher BBPS scores compared to those with fewer than 6900 footsteps (6.62 ± 1.8 vs. 5.92 ± 1.9, P = 0.003).In the univariate analysis, BBPS was found to be significantly associated with individuals under the age of 50 (OR: 2.45, 95% CI: 1.30-4.61, P = 0.006) and smoking status (OR: 0.41, 95% CI: 0.17-0.94, P = 0.043). In the multivariate analysis, the relationship between BBPS and age below 50 and smoking remained significant (OR: 2.50, 95% CI: 1.30-4.70, P = 0.005, and OR: 0.38, 95% CI: 0.16-0.93, P = 0.034, respectively).

CONCLUSION

A higher number of footsteps taken especially more than 6900 can significantly enhance bowel preparation; however, walking exercise as an intervention before colonoscopy is not significantly associated with BBPS. Also, older people and smokers seem to have fewer benefits from walking exercises for bowel preparation.

TRIAL REGISTRATION

ISRCTN32724024 (Registration date:22/08/2018).

Colorectal cancer surveillance by colonoscopy in a prospective, population-based long-term Swiss screening study - outcomes, adherence, and costs

Background The success of colorectal cancer (CRC) screening depends mainly on screening quality, patient adherence to surveillance, and costs. Consequently, it is essential to assess the performance over time.

Methods In 2000, a closed cohort study on CRC screening in individuals aged 50 to 80 was initiated in Uri, Switzerland. Participants who chose to undergo colonoscopy were followed over 18 years. We investigated the adherence to recommended surveillance and collected baseline characteristics and colonoscopy data. Risk factors at screening for the development of advanced adenomas were analyzed. Costs for screening and follow-up were evaluated retrospectively.

Results 1278 subjects with a screening colonoscopy were included, of which 272 (21.3%; 69.5% men) had adenomas, and 83 (6.5%) had advanced adenomas. Only 59.8% participated in a follow-up colonoscopy, half of them within the recommended time interval. Individuals with advanced adenomas at screening had nearly five times the risk of developing advanced adenomas compared to individuals without adenomas (24.3% vs. 5.0%, OR 4.79 CI 2.30–9.95). Individuals without adenomas developed advanced adenomas in 4.9%, including four cases of CRC; three of them without control colonoscopy. The villous component in adenomas smaller than 10 mm was not an independent risk factor. Costs for screening and follow-up added up to CHF 1’934’521 per 1’000 persons screened, almost half of them for follow-up examinations; 60% of these costs accounted for low-risk individuals.

Conclusion Our findings suggest that follow-up of screening colonoscopy should be reconsidered in Switzerland; in particular, long-term adherence is critical. Costs for follow-up could be substantially reduced by adopting less expensive long-term screening methods for low-risk individuals.

Combined Non-Invasive Cardiac Imaging and Genetic Testing of Elite Volleyball Players: A Ten-Year Experience

Sudden cardiac death in athletes is a devastating event. Although significant progress has been made in identifying the underlying pathophysiology and genetic basis for sudden cardiac death in young athletes, controversy exists regarding cost-effective screening measures to identify at-risk individuals. In this report we describe our ten-year experience performing cardiovascular assessments on 150 members of the United States Men’s and Women’s National Volleyball teams. Through a combination of history, physical, echocardiography and genetic testing, we have identified one previously undiagnosed athlete with Marfan syndrome, along with four others with a possible aortopathy. Taken together, this approach is a cost-effective strategy for the identification of at-risk tall athletes leading to potentially lifesaving interventions, and raises the issue of the feasibility of screening for all tall individuals.

Cancer diagnostic tools to aid decision-making in primary care: mixed-methods systematic reviews and cost-effectiveness analysis

BACKGROUND

Tools based on diagnostic prediction models are available to help general practitioners diagnose cancer. It is unclear whether or not tools expedite diagnosis or affect patient quality of life and/or survival.

OBJECTIVES

The objectives were to evaluate the evidence on the validation, clinical effectiveness, cost-effectiveness, and availability and use of cancer diagnostic tools in primary care.

METHODS

Two systematic reviews were conducted to examine the clinical effectiveness (review 1) and the development, validation and accuracy (review 2) of diagnostic prediction models for aiding general practitioners in cancer diagnosis. Bibliographic searches were conducted on MEDLINE, MEDLINE In-Process, EMBASE, Cochrane Library and Web of Science) in May 2017, with updated searches conducted in November 2018. A decision-analytic model explored the tools' clinical effectiveness and cost-effectiveness in colorectal cancer. The model compared patient outcomes and costs between strategies that included the use of the tools and those that did not, using the NHS perspective. We surveyed 4600 general practitioners in randomly selected UK practices to determine the proportions of general practices and general practitioners with access to, and using, cancer decision support tools. Association between access to these tools and practice-level cancer diagnostic indicators was explored.

RESULTS

Systematic review 1 - five studies, of different design and quality, reporting on three diagnostic tools, were included. We found no evidence that using the tools was associated with better outcomes. Systematic review 2 - 43 studies were included, reporting on prediction models, in various stages of development, for 14 cancer sites (including multiple cancers). Most studies relate to QCancer^® (ClinRisk Ltd, Leeds, UK) and risk assessment tools.

DECISION MODEL

In the absence of studies reporting their clinical outcomes, QCancer and risk assessment tools were evaluated against faecal immunochemical testing. A linked data approach was used, which translates diagnostic accuracy into time to diagnosis and treatment, and stage at diagnosis. Given the current lack of evidence, the model showed that the cost-effectiveness of diagnostic tools in colorectal cancer relies on demonstrating patient survival benefits. Sensitivity of faecal immunochemical testing and specificity of QCancer and risk assessment tools in a low-risk population were the key uncertain parameters.

SURVEY

Practitioner- and practice-level response rates were 10.3% (476/4600) and 23.3% (227/975), respectively. Cancer decision support tools were available in 83 out of 227 practices (36.6%, 95% confidence interval 30.3% to 43.1%), and were likely to be used in 38 out of 227 practices (16.7%, 95% confidence interval 12.1% to 22.2%). The mean 2-week-wait referral rate did not differ between practices that do and practices that do not have access to QCancer or risk assessment tools (mean difference of 1.8 referrals per 100,000 referrals, 95% confidence interval -6.7 to 10.3 referrals per 100,000 referrals).

LIMITATIONS

There is little good-quality evidence on the clinical effectiveness and cost-effectiveness of diagnostic tools. Many diagnostic prediction models are limited by a lack of external validation. There are limited data on current UK practice and clinical outcomes of diagnostic strategies, and there is no evidence on the quality-of-life outcomes of diagnostic results. The survey was limited by low response rates.

CONCLUSION

The evidence base on the tools is limited. Research on how general practitioners interact with the tools may help to identify barriers to implementation and uptake, and the potential for clinical effectiveness.

FUTURE WORK

Continued model validation is recommended, especially for risk assessment tools. Assessment of the tools' impact on time to diagnosis and treatment, stage at diagnosis, and health outcomes is also recommended, as is further work to understand how tools are used in general practitioner consultations.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42017068373 and CRD42017068375.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology programme and will be published in full in Health Technology Assessment; Vol. 24, No. 66. See the NIHR Journals Library website for further project information.

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.

Noninferiority clinical trial comparing the bowel cleansing efficacy of sodium phosphate tablets (Quiklean®) with a polyethylene glycol/bisacodyl kit

BACKGROUND

Efficient bowel cleansing is essential for a successful colonoscopy, but the ideal cleansing agent, volume, and pharmaceutical dosage form have yet to be determined. Small-volume cleansers enhance patient compliance.

AIM

To compare the bowel cleansing efficacy of 32-tablet sodium phosphate (Quiklean^®) with 2-L polyethylene glycol (PEG)/bisacodyl (Klean-Prep/ Dulcolax^®) under identical dietary recommendations.

METHODS

This multicenter, randomized, parallel-group, noninferiority clinical trial enrolled 472 outpatients, randomized 456 subjects, and scheduled 442 subjects to undergo colonoscopy (Quiklean^® = 222 and Klean-Prep/Dulcolax^® = 220). After bowel preparation, a colonoscopist performed the colonoscopy with video recorded for rating. The primary efficacy endpoint was the bowel cleansing quality using the Aronchick Scale. The secondary endpoints were the bowel cleansing efficacy of three colon segments, tolerability and acceptability, safety using the Ottawa bowel preparation scale, questionnaires by subjects, and monitoring of adverse events.

RESULTS

Success rates (Excellent + Good) of the bowel cleansing quality by Aronchick Scale were 98.6% (n = 205) and 97.6% (n = 204) in the Quiklean^® and Klean-Prep/Dulcolax^® groups, respectively. Quiklean^® demonstrated noninferiority over Klean-Prep/Dulcolax^® in colon cleansing efficacy. Quicken showed better tolerability and acceptability in the overall experience (was rated as excellent; 24.0% vs 17.2%; P = 0.0016) and the taste of the study preparation (was rated as excellent, 23.1% vs 13.4%; P < 0.0001) than Klean-Prep/Dulcolax^®. Safety profiles did not differ between the two groups. Our data indicate that Quiklean^® is an adequate, well-tolerated bowel cleansing preparation compared with the standard comparator Klean-Prep/Dulcolax^®.

CONCLUSION

Quiklean^® is sodium phosphate tablets available on Taiwan’s market for bowel preparation; it potentially offers patients an alternative to standard large-volume bowel preparation regimens and may, therefore, increase positive attitudes toward colonoscopies and participation rates.

Cost of Increasing Years-of-Life-Gained (YLG) Using Fecal Immunochemical Testing as a Population-Level Screening Model in a Rural Appalachian Population

PURPOSE

Given the innovation of fecal immunochemical testing (FIT) to detect polyps in the rectum and colon for removal by colonoscopy, it is important to determine the cost per Life-Year Gained (LYG) when using FIT as a population-level screening model. This is particularly true for medically underserved rural populations. Accordingly, the purpose of this study was to make this determination among rural Appalachians experiencing isolation and economic challenges.

METHODS

The study occurred in an 8-county area of southeastern Kentucky. Kits were distributed to 1,424 residents. Seven hundred thirty-two kits (51.4%) were completed and returned. A Markov decision-analytic model was developed using PrecisionTree 7.6.

FINDINGS

Reactive test results occurred for 144 of the completed kits (19.7%). Thirty-seven colonoscopies were verified, with 15 of these indicating precancerous changes or actual cancer. Program costs were estimated at $461,952, with the average cost per person screened estimated at $324. Cost per LYG was $7,912.

CONCLUSIONS

In contrast to an average cost per LYG of $17,200, our findings suggest a highly favorable cost-effectiveness ratio for this population of medically underserved rural residents. Cost-benefit analyses suggest that the screening program begins to yield positive net benefits at the stage when project recipients undergo colonoscopy, suggesting that this is the key step for behavioral intervention and intensified outreach.

Magnetic resonance spectroscopy and its application in colorectal cancer diagnosis and screening: A narrative review

There are several slightly invasive methods to detect colorectal carcinoma (CRC) including colonoscopy and sigmoidoscopy; but there is no noninvasive, accurate screening test. It is recommended to initiate screening at the age of 50 for non-familial CRC. Laboratory tests are routinely suggested if internal observation and imaging are recommended for further evaluation. Spectroscopic-based imaging, such as magnetic resonance spectroscopy (MRS) is an interesting and promising tool with the potential to be an alternative to some minimally invasive procedures, such as biopsy. Accordingly, MRS might be a suitable substitution for invasive methods, such as colonoscopy. This article aimed to review the studies that have evaluated the MRS technique as a screening tool in CRC.

Primary care visits increase utilization of evidence-based preventative health measures

BACKGROUND

Primary care visits can serve many purposes and potentially influence health behaviors. Although previous studies suggest that increasing primary care provider numbers may be beneficial, the mechanism responsible for the association is unclear, and have not linked primary care access to specific preventative interventions. We investigated the association between the number of times patients accessed their primary care provider team and the likelihood they received selected preventative health interventions.

METHODS

Patients with complete data sets from Sanford Health were categorized based on the number of primary care visits they received in a specified time period and the preventative health interventions they received. Patient characteristics were used in a propensity analysis to control for variables. Relative risks and 95% confidence intervals were calculated to estimate the likelihood of obtaining preventative measures based on number of primary care visits compared with patients who had no primary care visits during the specified time period.

RESULTS

The likelihood of a patient receiving three specified preventative interventions was increased by 127% for vaccination, 122% for colonoscopy, and 75% for mammography if the patient had ≥ 1 primary care visit per year. More primary care visits correlated with increasing frequency of vaccinations, but increased primary care visits beyond one did not correlate with increasing frequency of mammography or colonoscopy.

CONCLUSIONS

One or more primary care visits per year is associated with increased likelihood of specific evidence-based preventative care interventions that improve longitudinal health outcomes and decrease healthcare costs. Increasing efforts to track and increase the number of primary care visits by clinics and health systems may improve patient compliance with select preventative measures.

Rethinking prostate cancer screening: could MRI be an alternative screening test?

In the past decade rigorous debate has taken place about population-based screening for prostate cancer. Although screening by serum PSA levels can reduce prostate cancer-specific mortality, it is unclear whether the benefits outweigh the risks of false-positive results and overdiagnosis of insignificant prostate cancer, and it is not recommended for population-based screening. MRI screening for prostate cancer has the potential to be analogous to mammography for breast cancer or low-dose CT for lung cancer. A number of potential barriers and technical challenges need to be overcome in order to implement such a programme. We discuss different approaches to MRI screening that could address these challenges, including abbreviated MRI protocols, targeted MRI screening, longer rescreening intervals and a multi-modal screening pathway. These approaches need further investigation, and we propose a phased stepwise research framework to ensure proper evaluation of the use of a fast MRI examination as a screening test for prostate cancer.

A Randomized Trial Comparing the Bowel Cleansing Efficacy of Sodium Picosulfate/Magnesium Citrate and Polyethylene Glycol/Bisacodyl (The Bowklean Study)

Bowel cleansing is essential for a successful colonoscopy, but the ideal clearing agent and the volume have yet to be determined. A small-volume cleanser is important for patient compliance. This study aimed to compare the bowel cleansing efficacy, safety, tolerability, and acceptability of a 300-mL small-volume sodium picosulfate/magnesium citrate (PSMC) preparation-Bowklean with one 2-L polyethylene glycol (PEG)/bisacodyl-Klean-Prep/Dulcolax preparation under identical dietary recommendations. This multicenter, randomized, parallel-group, pre-specified noninferiority study enrolled 631 outpatients scheduled to undergo colonoscopy (Bowklean = 316 and Klean-Prep/Dulcolax = 315). After bowel preparation, an independent evaluator blinded to the subject's treatment allocation rated the quality of the colon cleansing. Efficacy was evaluated using the Aronchick Scale and Ottawa Bowel Preparation Scale (OPBS). Safety was assessed by monitoring adverse events. Tolerability and acceptability were measured via a patient questionnaire. Bowklean was non-interior to Klean-Prep/Dulcolax in overall colon cleansing but was associated with significantly better preparation quality. Notably, Bowklean was associated with significantly greater tolerability and acceptability of bowel preparations than Klean-Prep/Dulcolax. Safety profiles did not differ significantly between the groups. Our data indicate that Bowklean is a more effective and better-tolerated bowel cleansing preparation before colonoscopy than Klean-Prep/Dulcolax. Bowklean may therefore increase positive attitudes toward colonoscopies and participation rates.

Reduction of faecal immunochemical test false-positive results using a signature based on faecal bacterial markers

BACKGROUND

Colorectal cancer is the second commonest cause of cancer mortality. Some countries are implementing colorectal cancer screening to detect lesions at an early stage using non-invasive tools like the faecal immunochemical test. Despite affordability, this test shows a low sensitivity for precancerous lesions and a low positive predictive value for colorectal cancer, resulting in a high false-positive rate.

AIM

To develop a new, non-invasive colorectal cancer screening tool based on bacterial faecal biomarkers, which in combination with the faecal immunochemical test, could allow a reduction in the false-positive rate. This tool is called risk assessment of intestinal disease for colorectal cancer (RAID-CRC).

METHODS

We performed both the faecal immunochemical test and the bacterial markers analysis (RAID-CRC test) in stool samples from individuals with normal colonoscopy (167), non-advanced adenomas (88), advanced adenomas (30) and colorectal cancer (48). All the participants showed colorectal cancer-associated symptoms.

RESULTS

Performance of the faecal immunochemical test for advanced neoplasia (ie advanced adenoma and colorectal cancer) was determined by using the cut-off value established in Catalonia (20 µg haemoglobin/g of faeces) for a population-based screening approach. Sensitivity and specificity values of 83% and 80%, respectively, and positive and negative predictive values of 56% and 94%, respectively, were obtained. When both the immunological and the biological analysis were combined, the corresponding values were 80% and 90% for sensitivity and specificity, respectively, and 70% and 94% for positive and negative predictive values, respectively, resulting in a 50% reduction of the false-positive rate.

CONCLUSIONS

RAID-CRC test allows a substantial reduction in the faecal immunochemical test false-positive results (50%) in a symptomatic population. Further validation is indicated in a colorectal cancer-screening scenario.

Postpolypectomy Bleeding Prevention and More Complete Precancerous Colon Polyp Removal With Endoscopic Mucosal Stripping (EMS)

Background and Aims: Postpolypectomy bleeding and incomplete polyp removal are important complication and quality concerns of colonoscopy for colon cancer prevention. We investigated if endoscopic mucosal stripping (EMS) as a technical modification of traditional cold snare polypectomy to avoid submucosal injury during removal of non-pedunculated colon polyps could prevent postpolypectomy bleeding and facilitate complete polyp removal.

Methods: This is an Internal Review Board exemption-granted retrospective analysis of 5,142 colonoscopies with snare polypectomy performed by one of the authors (ZJC) at Minnesota Gastroenterology ambulatory endoscopy centers during a 12-year period divided into pre-EMS era (2005–2012, n = 2,973) and EMS era (2013–2016, n = 2169) with systemic adoption of EMS starting 2013. Change in postpolypectomy bleeding rate before and after EMS adoption and EMS polypectomy completeness were evaluated.

Results: Zero postpolypectomy bleeding case was found during EMS era (rate 0%) compared with 10 bleeding cases during pre-EMS era (rate 0.336%). This difference was statistically significant (P = 0.0055) and remained so after excluding 2 bleeding cases of pedunculated polyps (P = 0.012). All bleeding cases involved hot snare polypectomy. Histological examination of the involved polyps showed substantial submucosal vascular damage in contrast to a remarkable paucity of submucosa in comparable advanced polyps removed using EMS. Both biopsy and follow-up colonoscopy examination of the polypectomy sites confirmed that EMS more completely removed non-pedunculated advanced polyps.

Conclusions: EMS polypectomy was effective in preventing postpolypectomy bleeding and facilitated complete polyp removal.

Guideline Adherence to Colonoscopic Surveillance Intervals after Polypectomy in Korea: Results from a Nationwide Survey

Background/Aims

People around the world are increasingly choosing to undergo colorectal cancer screening via colonoscopy. As a result, guideline adherence to postpolypectomy colonoscopy surveillance has drawn increasing attention. The present study was performed to assess recognition and adherence to guidelines among primary care physicians and gastroenterologists and to identify characteristics associated with compliance.

Methods

A nationwide sample of primary care physicians employed at cancer screening facilities and registered members of the Korean Society of Gastrointestinal Endoscopy were recruited. Participants were asked to complete a survey of six hypothetical clinical scenarios designed to assess their potential course of action in response to screening or follow-up colonoscopy results. Frequencies and odds ratios and 95% confidence intervals for guideline adherence were estimated.

Results

The proportions of doctors recommending shortened colonoscopy surveillance intervals for low- and high-risk adenomas were greater than 90% among primary physicians and were much lower among gastroenterologists. Guideline adherence was relatively good among groups of doctors who were young, had a specialty in gastroenterology, worked at tertiary hospitals, and cared for an appropriate number of patients.

Conclusions

The present study reveals a remaining discrepancy between practitioner recommendations and current guidelines for postpolypectomy surveillance. Several factors were shown to be related to guideline adherence, suggesting a need for appropriate control and continuing education or training programs among particular groups of practitioners.

Critical Analysis of Markov Models Used for the Economic Evaluation of Colorectal Cancer Screening: A Systematic Review

BACKGROUND

The economic evaluation of colorectal cancer screening is challenging because of the need to model the underlying unobservable natural history of the disease.

OBJECTIVES

To describe the available Markov models and to critically analyze their main structural assumptions.

METHODS

A systematic search was performed in eight relevant databases (MEDLINE, Embase, Econlit, National Health Service Economic Evaluation Database, Health Economic Evaluations Database, Health Technology Assessment database, Cost-Effective Analysis Registry, and European Network of Health Economics Evaluation Databases), identifying 34 models that met the inclusion criteria. A comparative analysis of model structure and parameterization was conducted using two checklists and guidelines for cost-effectiveness screening models.

RESULTS

Two modeling techniques were identified. One strategy used a Markov model to reproduce the natural history of the disease and an overlaying model that reproduced the screening process, whereas the other used a single model to represent a screening program. Most of the studies included only adenoma-carcinoma sequences, a few included de novo cancer, and none included the serrated pathway. Parameterization of adenoma dwell time, sojourn time, and surveillance differed between studies, and there was a lack of validation and statistical calibration against local epidemiological data. Most of the studies analyzed failed to perform an adequate literature review and synthesis of diagnostic accuracy properties of the screening tests modeled.

CONCLUSIONS

Several strategies to model colorectal cancer screening have been developed, but many challenges remain to adequately represent the natural history of the disease and the screening process. Structural uncertainty analysis could be a useful strategy for understanding the impact of the assumptions of different models on cost-effectiveness results.

Cost-effectiveness of colorectal cancer screening in Ukraine

Background

Colorectal cancer is one of the most common cancers worldwide and is associated with high mortality when detected at a later stage. There is a paucity of studies from low and middle income countries to support the cost-effectiveness of colorectal cancer screening. We aim to analyze the cost-effectiveness of colorectal cancer screening compared to no screening in Ukraine, a lower-middle income country.

Methods

We developed a deterministic Markov cohort model to assess the cost-effectiveness of three colorectal cancer screening strategies [fecal occult blood test (FOBT) every year, flexible sigmoidoscopy with FOBT every 5 years, and colonoscopy every 10 years] compared to no screening. We modeled outcomes in terms of cost per quality-adjusted life-years (QALYs) over a lifetime time horizon. We performed sensitivity analyses on treatment adherence, test characteristics and costs. Analyses were conducted from the perspective of the Ministry of Health of Ukraine.

Results

The base-case lifetime cost-effectiveness analysis showed that all three screening strategies were cost saving compared to no screening, and among the three strategies, colonoscopy every 10 years was the dominant strategy compared to no screening with standard adherence to treatment. When decreased adherence to treatment was modeled, colonoscopy every 10 years was the most cost-effective strategy with an incremental cost-effectiveness ratio of $843 per QALY compared with no screening.

Conclusion

Our findings indicate that colorectal cancer screening can save money and improve health compared to no screening in Ukraine. Colonoscopy every 10 years is superior to the other screening modalities evaluated in this study. This knowledge can be used to concentrate efforts on developing a national screening program in Ukraine.

Novel evidence for a PIWI-interacting RNA (piRNA) as an oncogenic mediator of disease progression, and a potential prognostic biomarker in colorectal cancer

Background

Emerging evidence suggests that PIWI-interacting RNAs (piRNAs) may be important epigenetic regulators of gene expression in human cancers; however, their functional and clinical significance in colorectal cancer (CRC) remains unknown.

Methods

We performed piRNA expression profiling in paired cancer and normal tissues through small RNA-sequencing. The clinical significance of candidate piRNAs was investigated, and independently validated in 771 CRC patients from three independent cohorts. The biological function of piRNAs was characterized in cell lines, followed by identification and validation of downstream target genes in CRC tissues.

Results

We identified piR-1245 as a novel and frequently overexpressed noncoding RNA in CRC, and its expression significantly correlated with advanced and metastatic disease. Patients with high piR-1245 expression experienced significantly shorter overall survival, and multivariate analysis identified its expression to serve as an independent prognostic biomarker in CRC. Functionally, piR-1245 acts as an oncogene and promotes tumor progression, and gene expression profiling results identified a panel of downstream target-genes involved in regulating cell survival pathway. Based upon piRNA:mRNA sequence complementarity, we identified a panel of tumor suppressor genes (ATF3, BTG1, DUSP1, FAS,NFKBIA, UPP1, SESN2, TP53INP1 and MDX1) as direct targets of piR-1245, and successfully validated an inverse correlation between their expression and piR-1245 in CRC.

Conclusions

We for the first time have identified the role for a PIWI-interacting noncoding RNA, piR-1245, as a novel oncogene and a potential prognostic biomarker in colorectal cancer.

Electronic supplementary material

The online version of this article (10.1186/s12943-018-0767-3) contains supplementary material, which is available to authorized users.

Population-based screening improves histopathological prognostic factors in colorectal cancer

INTRODUCTION

Diagnosis of colorectal cancer (CRC) based on clinical symptoms is usually established in its advanced stages. One strategy for reducing mortality is the early detection and removal of preneoplastic and initial neoplastic lesions, even before the first symptoms appear, by means of population-based screening campaigns. The aim of the present study is to determine whether CRC diagnosed via a screening campaign has more favourable histopathological prognostic factors than when diagnosed in the symptomatic phase.

MATERIAL AND METHODS

The prospective study of all the patients undergoing programmed CRC surgery at the JM Morales Meseguer Hospital (Spain) is between 2004 and 2010. The patients were divided into two groups: one diagnosed from clinical symptoms and one through a screening campaign. The following factors were compared: tumour size; degree of tumour invasion of the wall; lymph node, perineural and lymphovascular involvement; tumour stage; and grade of differentiation.

RESULTS

Compared to the symptomatic group, the screen-detected patients had smaller-sized tumours (lesions of less than 5 cm in 84 vs 69.55%, p < 0.001), a lower degree of colorectal wall invasion (T0-1 in 36 vs 9.02%, p < 0.001), less lymph node involvement (N0 in 72 vs 58.76%, p > 0.05), less vascular invasion (7.20 vs 15.22%, p = 0.79) and less perineural invasion (6.4 vs 20.70%, p < 0.001). The TNM staging in the screening group was lower than in the symptomatic group (stage 0-1 in 50.40 vs 18.58%, p < 0.001).

CONCLUSIONS

CRC diagnosed through a population-based screening programme presents more favourable histopathological characteristics than that diagnosed from the appearance of symptoms.

Active Choice and Financial Incentives to Increase Rates of Screening Colonoscopy-A Randomized Controlled Trial

Behavioral economic approaches could increase uptake for colorectal cancer screening. We performed a randomized controlled trial of 2245 employees to determine whether an email containing a phone number for scheduling (control), an email with the active choice to opt in or opt out (active choice), or the active choice email plus a $100 incentive (financial incentive) increased colonoscopy completion within 3 months. Higher proportions of participants in the financial incentive group underwent screening (3.7%) than in the control (1.6%) or active choice groups (1.5%) (P = .01 and P < .01). We found no difference in uptake of screening between the active choice and control groups (P = .88). The $100 conditional incentive modestly but significantly increased colonoscopy use. ClinicalTrials.gov no: NCT02660671.

Comparison of outcomes between symptomatic and asymptomatic patients with colorectal cancer: a propensity score-matched analysis of surgical invasiveness, medical costs and oncological outcomes

Background and aims

Whether asymptomatic patients with colorectal cancer (CRC) who are treated in hospitals show better outcomes than symptomatic patients with CRC still remains unknown. The aim of this study was to evaluate differences in clinical benefits following treatment in asymptomatic and symptomatic patients with CRC.

Methods

This study was a retrospective cohort analysis with data obtained from records. A cohort of 145 asymptomatic and 123 symptomatic patients who underwent CRC surgery between January 2009 and December 2011 was enrolled. To reduce bias in comparing outcomes, propensity score (PS) analysis was used for matching of patients in the symptomatic and asymptomatic groups based on clinicopathological factors. Surgical invasiveness, medical costs and oncological outcomes were examined by unadjusted and PS-matched analysis.

Results

Tumours in the symptomatic group were more often diagnosed in advanced stages compared with tumours in the asymptomatic group. Therefore, fewer symptomatic group patients underwent minimally invasive surgery. Short-term outcomes, including amount of blood loss, duration of postoperative hospital stay and perioperative medical costs, were significantly better in the asymptomatic group. Although overall survival was significantly better in the asymptomatic group, there was no significant difference between the groups when the patients were adjusted on the basis of PS.

Conclusions

Though this study was limited by the retrospective nature and small sample size, favourable outcomes in asymptomatic patients were due to the higher proportion of patients in this group who were diagnosed with CRC in earlier stages, due to participation in CRC screening programmes.

Predicted Increases in Incidence of Colorectal Cancer in Developed and Developing Regions, in Association With Ageing Populations

BACKGROUND & AIMS

Population growth and changes in demographic structure are linked to trends in colorectal cancer (CRC) incidence. The aim of this study is to estimate future CRC incidence in the ageing population, and compare trends across developing and developed regions.

METHODS

Cancer and population data were extracted from the International Agency for Research on Cancer. Annual incidence rates for the major types of cancer in 118 selected populations were extracted from 102 cancer registries in 39 countries worldwide. We selected 8 jurisdictions (from the United States, Europe, and Asia) that reported 20-year cancer incidence rates since 1988. Time series models were constructed to project cancer incidence, by sex and age, to 2030. Incidence rates for persons older than 65 years were combined and further adjusted for change of ageing population. We compared age-adjusted incidence rates among the jurisdictions.

RESULTS

The total population older than 65 years old was 12,917,794 in 1988, and the number increased by almost 40% to 17,950,115 in 2007. In developed countries in the West CRC incidence is predicted to decrease by 16.3% in the United States, increase by 4.8% in the United Kingdom, and increase by 4.7% in Sweden by 2030. In developing countries, such as China (Shanghai), Croatia, and Costa Rica, CRC incidence is predicted to increase in a steep curve by 2030 because of the growing population and ageing effect; in 2030, the incidence increases were 60.5% for China, 47.0% for Croatia, and 18.5% for Costa Rica. We also predict CRC incidence will increase greatly by 2030 in Japan and Hong Kong, which are developed regions.

CONCLUSIONS

With the exception of the United States, the incidence of CRC is expected to continue to rise in most regions in the coming decades, due to population growth and changes in demographic structure. The predicted increases are more marked in developing regions with limited health care resources.

The Roles of Carcinoembryonic Antigen in Liver Metastasis and Therapeutic Approaches

Metastasis is a highly complicated and sequential process in which primary cancer spreads to secondary organic sites. Liver is a well-known metastatic organ from colorectal cancer. Carcinoembryonic antigen (CEA) is expressed in most gastrointestinal, breast, and lung cancer cells. Overexpression of CEA is closely associated with liver metastasis, which is the main cause of death from colorectal cancer. CEA is widely used as a diagnostic and prognostic tumor marker in cancer patients. It affects many steps of liver metastasis from colorectal cancer cells. CEA inhibits circulating cancer cell death. CEA also binds to heterogeneous nuclear RNA binding protein M4 (hnRNP M4), a Kupffer cell receptor protein, and activates Kupffer cells to secrete various cytokines that change the microenvironments for the survival of colorectal cancer cells in the liver. CEA also activates cell adhesion-related molecules. The close correlation between CEA and cancer has spurred the exploration of many CEA-targeted approaches as anticancer therapeutics. Understanding the detailed functions and mechanisms of CEA in liver metastasis will provide great opportunities for the improvement of anticancer approaches against colorectal cancers. In this report, the roles of CEA in liver metastasis and CEA-targeting anticancer modalities are reviewed.

Understanding the Effects of Competition for Constrained Colonoscopy Services with the Introduction of Population-level Colorectal Cancer Screening

BACKGROUND

Median wait times for gastroenterology services in Canada exceed consensus-recommended targets and have worsened substantially over the past decade. Meanwhile, efforts to control colorectal cancer have shifted their focus to screening asymptomatic, average-risk individuals. Along with increasing prevalence of colorectal cancer due to an aging population, screening programs are expected to add substantially to the existing burden on colonoscopy services, and create competition for limited services among individuals of varying risk. Failure to understand the effects of operational programmatic screening decisions may cause unintended harm to both screening participants and higher-risk patients, make inefficient use of limited health care resources, and ultimately hinder a program's success.

METHODS

We present a new simulation model (Simulation of Cancer Outcomes for Planning Exercises, or SCOPE) for colorectal cancer screening which, unlike many other colorectal cancer screening models, reflects the effects of competition for limited colonoscopy services between patient groups and can be used to guide planning to ensure adequate resource allocation. We include verification and validation results for the SCOPE model.

RESULTS

A discrete event simulation model was developed based on an epidemiological representation of colorectal cancer in a sample population. Colonoscopy service and screening modules were added to allow observation of screening scenarios and resource considerations. The model reproduces population-based data on prevalence of colorectal cancer by stage, and mortality by cause of death, age, and sex, and attendant demand and wait times for colonoscopy services.

CONCLUSIONS

The study model differs from existing screening models in that it explicitly considers the colonoscopy resource implications of screening activities and the impact of constrained resources on screening effectiveness.

Diversity of model approaches for breast cancer screening: a review of model assumptions by The Cancer Intervention and Surveillance Network (CISNET) Breast Cancer Groups

The National Cancer Institute-sponsored Cancer Intervention and Surveillance Network program on breast cancer is composed of seven research groups working largely independently to model the impact of screening and adjuvant therapy on breast cancer mortality trends in the US from 1975 to 2000. Each of the groups has chosen a different modeling methodology without purposeful attempt to be in contrast with each other. The seven groups have met biannually since November 2000 to discuss their methodology and results. This article investigates the differences in methodology. To facilitate this comparison, each of the groups submitted a description of their model into a uniformly structured web based ‘model profiler’. Six of the seven models simulate a preclinical natural history that cannot be observed directly with parameters estimated from published evidence concerning screening and therapy effects. The remaining model regards published evidence on intervention effects as prior information and updates that with information from the US population in a Bayesian type analysis. In general, the differences between the models appear to be small, particularly among the models driven by natural history assumptions. However, we demonstrate that such apparently small differences can have a large impact on surveillance of population trends. We describe a systematic approach to evaluating differences in model assumptions and results, as well as differences in modeling culture underlying the differences in model structure and parameters.

Knowledge, Attitude and Intentions Related to Colorectal Cancer Screening Using Faecal Occult Blood Tests in a Rural Australian Population

A telephone survey with 604 men and women without history of colorectal cancer (CRC)(age 50-74 years) explored knowledge of, attitudes toward, and intention to screen for CRC using faecal occult blood tests (FOBT) in a rural Australian population. Overall, 53% intended to participate in and 86% would follow a doctor's recommendation for FOBT screening. In contrast, only 18% had ever had a FOBT, and fewer than 60% of those with high-risk family history had undergone appropriate screening for CRC. Prior use of FOBT ( OR=3.2) , high perceived susceptibility to CRC ( OR=2.4), belief in the importance of screening despite the absence of symptoms ( OR=2.1) were positively and older age ( OR = 0.5) was negatively related to screening intention in multivariate logistic regression analysis. A doctor's recommendation improved screening intention among those who never tested for CRC before but believe in the importance of early treatment. This study highlights the lack of compliance with standard CRC screening recommendations in Australia and provides evidence for the importance of continued educational efforts, with the particular emphasis on older adults and the medical community. Asia Pac JPublic Health 2003; 1 5(1): 50-56.

Colorectal Cancer Screening Based on Age and Gender: A Cost-Effectiveness Analysis

We evaluated whether age- and gender-based colorectal cancer screening is cost-effective.Recent studies in the United States identified age and gender as 2 important variables predicting advanced proximal neoplasia, and that women aged <60 to 70 years were more suited for sigmoidoscopy screening due to their low risk of proximal neoplasia. Yet, quantitative assessment of the incremental benefits, risks, and cost remains to be performed.Primary care screening practice (2008-2015).A Markov modeling was constructed using data from a screening cohort. The following strategies were compared according to the Incremental Cost Effectiveness Ratio (ICER) for 1 life-year saved: flexible sigmoidoscopy (FS) 5 yearly; colonoscopy 10 yearly; FS for each woman at 50- and 55-year old followed by colonoscopy at 60- and 70-year old; FS for each woman at 50-, 55-, 60-, and 65-year old followed by colonoscopy at 70-year old; FS for each woman at 50-, 55-, 60-, 65-, and 70-year old. All male subjects received colonoscopy at 50-, 60-, and 70-year old under strategies 3 to 5.From a hypothetical population of 100,000 asymptomatic subjects, strategy 2 could save the largest number of life-years (4226 vs 2268 to 3841 by other strategies). When compared with no screening, strategy 5 had the lowest ICER (US$42,515), followed by strategy 3 (US$43,517), strategy 2 (US$43,739), strategy 4 (US$47,710), and strategy 1 (US$56,510). Strategy 2 leads to the highest number of bleeding and perforations, and required a prohibitive number of colonoscopy procedures. Strategy 5 remains the most cost-effective when assessed with a wide range of deterministic sensitivity analyses around the base case.From the cost effectiveness analysis, FS for women and colonoscopy for men represent an economically favorable screening strategy. These findings could inform physicians and policy-makers in triaging eligible subjects for risk-based screening, especially in countries with limited colonoscopic resources. Future research should study the acceptability, feasibility, and feasibility of this risk-based strategy in different populations.

Validation of the Asia Pacific Colorectal Screening (APCS) score in a Western population: An alternative screening tool

BACKGROUND AND AIM

Colorectal cancer (CRC) screening is based on colonoscopy or fecal occult blood tests, but is imperfect and costly. The Asia Pacific Colorectal Screening Score (APCS) is derived from age, sex, family history of CRC, and smoking history and has been validated in Asian populations. Validation in a Western population is, however, yet to be tested.

METHODS

In a teaching hospital, patients underwent colonoscopy for standard indications and screening over 18 months. Data was collected on age, sex, family history of CRC, smoking, weight, ethnicity, and symptoms. Evaluation of the APCS to predict colonoscopy findings (polyps, adenoma, high risk adenoma, and CRC) was performed.

RESULTS

A total of 645 patients were prospectively recruited (46.7% male, median age 57 years); 17.8% were average risk (AR), 50.9% were moderate risk (MR), and 31.3% high risk (HR) on APCS. High risk adenomas (AA) were seen in 14.9% of the HR, 5.2% MR, and 0.9% LR patients, P < 0.0001. Comparing HR and MR to AR patients demonstrated significantly elevated relative risk (RR) for AA: 17.1 (95% confidence interval [CI] 2.4-123; P = 0.0001), and adenoma 6.0 (0.80-44.3; P = 0.044). Comparing HR to MR groups for AA, the RR was 2.87 (1.62-5.06; P = 0.0001). Symptoms did not predict findings (odds ratio [OR]: 1.06 [0.75-1.48]; P = 0.75). Body mass index (BMI) <20 kg/m(2) was protective against colonic polyps (OR: 0.28, 95%CI: 0.11-0.74; P = 0.010), adenoma (0.08, 0.01-0.62; P = 0.015), and AA (perfect prediction, OR 2.35 × 10(-8)).

CONCLUSIONS

APCS predicts colonic findings in a Western population, to a greater extent than in Asians, independent to symptoms. Low body weight carries a strong protective effect against colonic neoplasia.

Improving the utility of colonoscopy: Recent advances in practice

Colonoscopy is a frequently performed diagnostic and therapeutic test and the primary screening tool in several nationalized bowel cancer screening programs. There has been a considerable focus on maximizing the utility of colonoscopy. This has occurred in four key areas: Optimizing patient selection to reduce unnecessary or low yield colonoscopy has offered cost-benefit improvements in population screening. Improving quality assurance, through the development of widely accepted quality metrics for use in individual practice and the research setting, has offered measurable improvements in colonoscopic yield. Significant improvements have been demonstrated in colonoscopic technique, from the administration of preparation to the techniques employed during withdrawal of the colonoscope. Improved techniques to avoid post-procedural complications have also been developed-further maximizing the utility of colonoscopy. The aim of this review is to summarize the recent evidence-based advances in colonoscopic practice that contribute to the optimal practice of colonoscopy.

Optimal use of colonoscopy and fecal immunochemical test for population-based colorectal cancer screening: a cost-effectiveness analysis using Japanese data

OBJECTIVE

There have been few cost-effectiveness analyses of population-based colorectal cancer screening in Japan, and there is no consensus on the optimal use of total colonoscopy and the fecal immunochemical test for colorectal cancer screening with regard to cost-effectiveness and total colonoscopy workload. The present study aimed to examine the cost-effectiveness of colorectal cancer screening using Japanese data to identify the optimal use of total colonoscopy and fecal immunochemical test.

METHODS

We developed a Markov model to assess the cost-effectiveness of colorectal cancer screening offered to an average-risk population aged 40 years or over. The cost, quality-adjusted life-years and number of total colonoscopy procedures required were evaluated for three screening strategies: (i) a fecal immunochemical test-based strategy; (ii) a total colonoscopy-based strategy; (iii) a strategy of adding population-wide total colonoscopy at 50 years to a fecal immunochemical test-based strategy.

RESULTS

All three strategies dominated no screening. Among the three, Strategy 1 was dominated by Strategy 3, and the incremental cost per quality-adjusted life-years gained for Strategy 2 against Strategies 1 and 3 were JPY 293 616 and JPY 781 342, respectively. Within the Japanese threshold (JPY 5-6 million per QALY gained), Strategy 2 was the most cost-effective, followed by Strategy 3; however, Strategy 2 required more than double the number of total colonoscopy procedures than the other strategies.

CONCLUSIONS

The total colonoscopy-based strategy could be the most cost-effective for population-based colorectal cancer screening in Japan. However, it requires more total colonoscopy procedures than the other strategies. Depending on total colonoscopy capacity, the strategy of adding total colonoscopy for individuals at a specified age to a fecal immunochemical test-based screening may be an optimal solution.

New York Citywide Colon Cancer Control Coalition: A public health effort to increase colon cancer screening and address health disparities

BACKGROUND

Although screening for colorectal cancer (CRC) is a widely accepted concept nationally and screening rates are increasing, there are differences in screening rates between states and within states.

METHODS

In an effort to increase screening rates and ensure equal access with respect to race/ethnicity, the New York City Department of Health and Mental Hygiene formed a coalition of stakeholders in 2003, with its primary focus on colonoscopy, to develop and implement strategies across the city to achieve this goal.

RESULTS

From a screening colonoscopy rate of only 42% in 2003, these concerted efforts contributed to achieving a screening rate of 62% by 2007 and a screening rate of almost 70% in 2014 with the elimination of racial and ethnic disparities.

CONCLUSIONS

This article provides details of how this program was successfully conceived, implemented, and sustained in the large urban population of New York City. The authors hope that by sharing the many elements involved and the lessons learned, they may help other communities to adapt these experiences to their own environments so that CRC screening rates can be maximized. Cancer 2016;122:269-277. © 2015 American Cancer Society.

The comparative cost-effectiveness of colorectal cancer screening using faecal immunochemical test vs. colonoscopy

Faecal immunochemical tests (FITs) and colonoscopy are two common screening tools for colorectal cancer(CRC). Most cost-effectiveness studies focused on survival as the outcome, and were based on modeling techniques instead of real world observational data. This study evaluated the cost-effectiveness of these two tests to detect colorectal neoplastic lesions based on data from a 5-year community screening service. The incremental cost-effectiveness ratio (ICER) was assessed based on the detection rates of neoplastic lesions, and costs including screening compliance, polypectomy, colonoscopy complications, and staging of CRC detected. A total of 5,863 patients received yearly FIT and 4,869 received colonoscopy. Compared with FIT, colonoscopy detected notably more adenomas (23.6% vs. 1.6%) and advanced lesions or cancer (4.2% vs. 1.2%). Using FIT as control, the ICER of screening colonoscopy in detecting adenoma, advanced adenoma, CRC and a composite endpoint of either advanced adenoma or stage I CRC was US$3,489, US$27,962, US$922,762 and US$23,981 respectively. The respective ICER was US$3,597, US$439,513, -US$2,765,876 and US$32,297 among lower-risk subjects; whilst the corresponding figure was US$3,153, US$14,852, US$184,162 and US$13,919 among higher-risk subjects. When compared to FIT, colonoscopy is considered cost-effective for screening adenoma, advanced neoplasia, and a composite endpoint of advanced neoplasia or stage I CRC.

Screening strategies for colorectal cancer among patients with nonalcoholic fatty liver disease and family history

Patients with nonalcoholic fatty liver disease (NAFLD) and family history of colorectal cancer (CRC) are at higher risks but how they should be screened remains uncertain. Hence, we evaluated the cost-effectiveness of CRC screening among patients with NAFLD and family history by different strategies. A hypothetical population of 100,000 subjects aged 40-75 years receive: (i) yearly fecal immunochemical test (FIT) at 50 years; (ii) flexible sigmoidoscopy (FS) every 5 years at 50 years; (iii) colonoscopy 10 yearly at 50 years; (iv) colonoscopy 10 yearly at 50 years among those with family history/NAFLD and yearly FIT at 50 years among those without; (v) colonoscopy 10 yearly at 40 years among those with family history/NAFLD and yearly FIT at 50 years among those without and (vi) colonoscopy 10 yearly at 40 years among those with family history/NAFLD and colonoscopy 10 yearly at 50 years among those without. The incremental cost-effectiveness ratio (ICER) was studied by Markov modeling. It was found that colonoscopy, FS and FIT reduced incidence of CRC by 49.5, 26.3 and 23.6%, respectively. Using strategies 4, 5 and 6, the corresponding reduction in CRC incidence was 29.9, 30.9 and 69.3% for family history, and 33.2, 34.7 and 69.8% for NAFLD. Compared with no screening, strategies 4 (US$1,018/life-year saved) and 5 (US$7,485) for family history offered the lowest ICER, whilst strategy 4 (US$5,877) for NAFLD was the most cost-effective. These findings were robust when assessed with a wide range of deterministic sensitivity analyses around the base case. These indicated that screening patients with family history or NAFLD by colonoscopy at 50 years was economically favorable.

Decreased expression of heat shock protein 20 in colorectal cancer and its implication in tumorigenesis

Heat shock protein 20 (HSP20), which is a member of the small heat shock protein family, is known to participate in many pathological processes, such as asthma, intimal hyperplasia, and insulin resistance. However, the function of HSP20 in cancer development is not yet fully understood. In this study, we identified HSP20 as a down-regulated protein in 20 resected colorectal cancer (CRC) specimens compared with their paired normal tissues. Because HSP20 proteins were barely detectable in HCT-116 cells (a human colorectal cancer cell line), recombinant adenovirus encoding HSP20 (Ad-HSP20) was used to induce HSP20 overexpression in HCT-116 cells. Infection of Ad-HSP20, but not control adenovirus (Ad-GFP), reduced viability, and induced massive apoptosis in a time-dependent manner. The forced expression of HSP20 enhanced caspase-3/7 activity and down-regulated the anti-apoptotic Bcl-xL and Bcl-2 mRNA and protein levels. In addition, immunohistochemical analysis of 94 CRC specimens for HSP20 protein showed that reduced HSP20 expression was related to advanced TNM stage, lymph node metastasis, and tumor recurrence. Our study shows, for the first time, that expression of the HSP20 protein has a pro-death role in colorectal cancer cells. Therefore, HSP20 may have value as a prognostic tumor marker and its overexpression might be a novel strategy for CRC therapy.

Nonneoplastic polypectomy during screening colonoscopy: the impact on polyp detection rate, adenoma detection rate, and overall cost

BACKGROUND

The frequency of nonneoplastic polypectomy (NNP) and its impact on the polyp detection rate (PDR) is unknown. The correlation between NNP and adenoma detection rate (ADR) and its impact on the cost of colonoscopy has not been investigated.

OBJECTIVE

To determine the rate of NNP in screening colonoscopy, the impact of NNP on the PDR, and the correlation of NNP with ADR. The increased cost of NNP during screening colonoscopy also was calculated.

DESIGN

We reviewed all screening colonoscopies. PDR and ADR were calculated. We then calculated a nonneoplastic polyp detection rate (patients with ≥1 nonneoplastic polyp).

SETTING

Tertiary-care referral center.

PATIENTS

Patients who underwent screening colonoscopies from 2010 to 2011.

INTERVENTIONS

Colonoscopy.

MAIN OUTCOME MEASUREMENTS

ADR, PDR, NNP rate.

RESULTS

A total of 1797 colonoscopies were reviewed. Mean (±standard deviation) PDR was 47.7%±12.0%, and mean ADR was 27.3%±6.9%. The overall NNP rate was 10.4%±7.1%, with a range of 2.4% to 28.4%. Among all polypectomies (n=2061), 276 were for nonneoplastic polyps (13.4%). Endoscopists with a higher rate of nonneoplastic polyp detection were more likely to detect an adenoma (odds ratio 1.58; 95% confidence interval, 1.1-1.2). With one outlier excluded, there was a strong correlation between ADR and NNP (r=0.825; P<.001). The increased cost of removal of nonneoplastic polyps was $32,963.

LIMITATIONS

Retrospective study.

CONCLUSION

There is a strong correlation between adenoma detection and nonneoplastic polyp detection. The etiology is unclear, but nonneoplastic polyp detection rate may inflate the PDR for some endoscopists. NNP also adds an increased cost. Increasing the awareness of endoscopic appearances through advanced imaging techniques of normal versus neoplastic tissue may be an area to improve cost containment in screening colonoscopy.

Familial colorectal cancer screening: When and what to do?

Colorectal cancer (CRC) is the third leading cause of death worldwide and represents a clinical challenge. Family members of patients affected by CRC have an increased risk of CRC development. In these individuals, screening is strongly recommended and should be started earlier than in the population with average risk, in order to detect neoplastic precursors, such as adenoma, advanced adenoma, and nonpolypoid adenomatous lesions of the colon. Fecal occult blood test (FOBT) is a non invasive, widespread screening method that can reduce CRC-related mortality. Sigmoidoscopy, alone or in addition to FOBT, represents another screening strategy that reduces CRC mortality. Colonoscopy is the best choice for screening high-risk populations, as it allows simultaneous detection and removal of preneoplastic lesions. The choice of test depends on local health policy and varies among countries.

Choosing the optimal method in programmatic colorectal cancer screening: current evidence and controversies

Colorectal cancer (CRC) is an important health problem all over the world, being the third most common cancer and the second leading cause of cancer-related death in Western countries. The most important strategy for CRC prevention is screening (i.e. secondary prevention). Since it is widely accepted that adenomas and serrated polyps are the precursors of the vast majority of CRC, early detection and removal of these lesions is associated with a reduction of CRC incidence and, consequently, mortality. Moreover, cancers detected by screening are usually diagnosed at early stages and, therefore, curable by endoscopic or surgical procedures. This review will be address CRC screening strategies in average-risk population, which is defined by those individuals, men and women, 50 years of age or older, without any additional personal or familial predisposing risk factor. In order to maximize the impact of screening and ensure high coverage and equity of access, only organized screening programs (i.e. programmatic screening) should be implemented, as opposed to case-finding or opportunistic screening. For that reason and considering that the optimal approach for colorectal screening may differ depending on the scenario, this review will be focused on the advantages and limitations of each screening strategy in an organized setting.

Knowledge and practice of colorectal screening in a suburban group of Iraqi American women

Colorectal cancer (CRC) was the second most common cancer among women in 2008, accounting for 571,000 cases, and 9.4% of all cancer cases afflicting women worldwide. According to the World Health Organization (WHO) and the Iraqi National Cancer Registry (INCR), Iraq has seen a steady rise in CRC rates among its general population over the past several decades. Despite Iraq's increasing national incidence of CRC and the growth of the US' Iraqi immigrant population over the last 10 years, little remains known about the prevalence of CRC among the latter population, their knowledge of CRC and associated risk factors, or their behavioral intent and practices regarding CRC screening. The aims of this study were to (1) examine the knowledge of and adherence to National Cancer Institute screening recommendations for CRC among a population of Iraqi women living in the Washington D.C. Metropolitan Area and (2) test the efficacy of a one-time educational intervention conducted using linguistically and culturally appropriate materials to raise awareness of, and promote future adherence to, CRC screening methods. This descriptive study used a pre/post design with a 12-month follow-up. Following extensive dissemination of information regarding the study in the Iraqi American community in the study location, 50 women were initially recruited, of whom 32 participated in the study. The study's findings revealed that the participants generally had low baseline levels of CRC screening adherence and preventive knowledge that significantly improved after the intervention as demonstrated by pre- and post-assessments of knowledge and behavior. These findings could be used to raise awareness (1) among clinicians regarding the need for early detection and screening of and referral for CRC treatment among Iraqi American women and (2) among Iraqi American women about risk factors for this disease and the importance of early detection and screening. The study also highlights the need for a larger study of knowledge, attitudes, and perceptions among both this population and the clinicians who serve them.

Impact of a Multifaceted Intervention on Promoting Adherence to Screening Colonoscopy Among Persons in HIV Primary Care: A Pilot Study

HIV-positive patients have lower colon cancer screening rates and are at increased risk for colon adenocarcinoma. We tested a transdisciplinary prevention model to increase provider and patient adherence to screening colonoscopy. Of 1,339 HIV-positive patients with scheduled clinic appointments during the period September to November 2009, we identified 400 records of eligible patients ≥50 years and retrospectively reviewed for screening colonoscopy referral; if never referred, flagged for referral at next visit. Providers referred 43.5% (174/400) patients and 36.2% (63/174) kept appointment. Within 6 months before the study, 337 patients attended clinic and providers referred 18%. Note that 211/226 patients with flagged records attended clinic at least once during the study 6-month period and providers referred (43.6%). The referral rate for flagged records was significantly different from that for the prior 6 months (p < 0.0001). A randomized trial compared the efficacy of patient decision support versus usual care on screening adherence. Among patients randomized to intervention 17 (51.5%) compared to usual care only 16 (48.5%), intervention group showed significant adherence of 70.6% (12/17) versus 29.4% (5/16), (p = 0.024). In addition, intervention patients had good bowel preparation of 76.9% (10/13) versus usual care 23.1% (3/13), (p = 0.05). This transdisciplinary intervention model significantly increased provider and patient screening colonoscopy behavior.

Colonoscopy in Colorectal Cancer Screening: Current Aspects

Colonoscopy represents a very important diagnostic modality for screening for colorectal cancer, because it has the ability to both detect and effectively remove pro-malignant and malignant lesions. It is recommended by almost all international and national gastroenterology and cancer societies, as an initial screening modality or, following a positive fecal occult blood test, to be performed every 10 years in individuals of average risk starting from the age of 50. However, a significant problem is the so-called post-screening (interval) polyps and cancers found some years after the index colonoscopy. In order to reduce the rate of interval cancers it is extremely necessary to optimize the quality and effectiveness of colonoscopy. Bowel preparation is of paramount importance for both accurate diagnosis and subsequent treatment of lesions found on colonoscopy. The quality of bowel preparation could be significantly improved by splitting the dose regimens, a strategy that has been shown to be superior to single-dose regimen. A good endoscopic technique and optimal withdrawal time offering adequate time for inspection, would further optimize the rate of cecal intubation and the number of lesions detected. During the last years, sophisticated devices have been introduced that would further facilitate cecal intubation. The percentage of total colonoscopies is now super-passing the level of 95 % allowing the adenoma detection rate to be greater than the suggestive level of 25 % in men and 15 % in women. This review aims to provide the reader with the current knowledge concerning indications, usefulness, limitations and future perspectives of this probably most important screening technique for colorectal cancer available today.

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.