Cost-Effectiveness of Colorectal Cancer Screening Strategies-A Systematic Review

Machine Learning Models Cannot Replace Screening Colonoscopy for the Prediction of Advanced Colorectal Adenoma

Screening for colorectal cancer (CRC) continues to rely on colonoscopy and/or fecal occult blood testing since other (non-invasive) risk-stratification systems have not yet been implemented into European guidelines. In this study, we evaluate the potential of machine learning (ML) methods to predict advanced adenomas (AAs) in 5862 individuals participating in a screening program for colorectal cancer. Adenomas were diagnosed histologically with an AA being ≥ 1 cm in size or with high-grade dysplasia/villous features being present. Logistic regression (LR) and extreme gradient boosting (XGBoost) algorithms were evaluated for AA prediction. The mean age was 58.7 ± 9.7 years with 2811 males (48.0%), 1404 (24.0%) of whom suffered from obesity (BMI ≥ 30 kg/m²), 871 (14.9%) from diabetes, and 2095 (39.1%) from metabolic syndrome. An adenoma was detected in 1884 (32.1%), as well as AAs in 437 (7.5%). Modelling 36 laboratory parameters, eight clinical parameters, and data on eight food types/dietary patterns, moderate accuracy in predicting AAs with XGBoost and LR (AUC-ROC of 0.65–0.68) could be achieved. Limiting variables to established risk factors for AAs did not significantly improve performance. Moreover, subgroup analyses in subjects without genetic predispositions, in individuals aged 45–80 years, or in gender-specific analyses showed similar results. In conclusion, ML based on point-prevalence laboratory and clinical information does not accurately predict AAs.

Strongly Divergent Impact of Adherence Patterns on Efficacy of Colorectal Cancer Screening: The Need to Refine Adherence Statistics

INTRODUCTION

The performance of colorectal cancer (CRC) screening programs depends on the adherence to screening offers. However, identical adherence levels may result from varying patterns of the population's screening behavior. We quantified the effects of different adherence patterns on the long-term performance of CRC screening for annual fecal immunochemical testing and screening colonoscopy at 10-year intervals.

METHODS

Using a multistate Markov model, we simulated scenarios where, while at the same overall adherence level, a certain proportion of the population adheres to all screening offers (selective adherence) or the entire population uses the screening offers at some point(s) of time, albeit not in the recommended frequency (sporadic adherence). Key outcomes for comparison were the numbers of prevented CRC cases and prevented CRC deaths after 50 simulated years.

RESULTS

For screening with annual fecal immunochemical testing at adherence levels of 10%-50%, ratios of prevented CRC cases (CRC deaths) resulting from a sporadic vs a selective pattern ranged from 1.8 to 4.4 (1.9-5.3) for men and from 1.7 to 3.6 (1.8-4.4) for women, i.e., up to 4-5 times more CRC cases and deaths were prevented when the population followed a sporadic instead of a selective adherence pattern. Comparisons of simulated scenarios for screening colonoscopy revealed similar patterns.

DISCUSSION

Over a lifelong time frame, large numbers of irregular screening attendees go along with much larger preventive effects than small numbers of perfectly adhering individuals. In clinical practice, efforts to reach as many people as possible at least sporadically should be prioritized over efforts to maximize adherence to repeat screening offers.

The role of sex and rurality in cancer fatalistic beliefs and cancer screening utilization in Florida

BACKGROUND

People's fatalistic beliefs about cancer can influence their cancer prevention behaviors. We examined the association between fatalistic beliefs and breast and colorectal cancer screening among residents of north-central Florida and tested whether there exists any sex or rural-non-rural disparities in the association.

METHODS

We conducted a cross-sectional, random digit dialing telephone survey of 895 adults residing in north-central Florida in 2017. Using weighted logistic models, we examined the association between (1) respondents' sociodemographic characteristics and cancer fatalistic beliefs and (2) cancer fatalistic beliefs and cancer screening utilization among screening eligible populations. We tested a series of sex and rurality by fatalistic belief interactions.

RESULTS

Controlling for sociodemographics, we found the agreement with "It seems like everything causes cancer" was associated with a higher likelihood of having a mammogram (odds ratio [OR]: 3.34; 95% confidence interval [CI]: 1.17-9.51), while the agreement with "Cancer is most often caused by a person's behavior or lifestyle" was associated with a higher likelihood of having a blood stool test (OR: 1.85; 95% CI: 1.12-3.05) or a sigmoidoscopy or colonoscopy among women (OR: 2.65; 95% CI: 1.09-6.44). We did not observe any rural-non-rural disparity in the association between fatalistic beliefs and cancer screening utilization.

CONCLUSIONS

Some, but not all, cancer fatalistic beliefs are associated with getting breast and colorectal cancer screening in north-central Florida. Our study highlights the need for more research to better understand the social and cultural factors associated with cancer screening utilization.

De Novo Colorectal and Pancreatic Cancer in Liver-Transplant Recipients: Identifying the Higher-Risk Populations

BACKGROUND AND AIMS

Gastrointestinal (GI) malignancies are common after liver transplantation. The aim of this study was to identify the risk and timing of the more common GI malignancies, colorectal and pancreatic cancer, to aid in optimizing potential posttransplant screening practices.

APPROACH AND RESULTS

Data from the United Network for Organ Sharing database of all adult liver-transplant recipients from 1997 to 2017 were analyzed and a comparison made with cancer incidence from general population data using Surveillance, Epidemiology, and End Results data. Of 866 de novo GI malignancies, 405 colorectal and 216 pancreas were identified. The highest cumulative incidence for colorectal cancer occurred in recipients with primary sclerosing cholangitis (PSC), recipients over the age of 50 with non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC)/cholangiocarcinoma (CCA), and females >50 years with alcohol-associated liver disease and HCC/CCA, with risk increasing above the general population within 5 years of transplant. Patients with PSC and HCC/CCA or NASH and HCC/CCA have the highest cumulative incidence of pancreatic cancer also rising within 5 years following transplant, with those patients >50 years old conferring the highest risk.

CONCLUSIONS

These data identify a high-risk cohort that warrants consideration for intensified individualized screening practices for colorectal cancer after liver transplantation. In addition to recipients with PSC, further study of recipients with NASH and HCC/CCA and females with alcohol-associated liver disease and HCC/CCA may be better tailored to colorectal cancer screening ideals. Higher-risk patient populations for pancreatic cancer (PSC and NASH with HCC/CCA) would benefit from further study to determine potential screening practices. GI malignancies occur at higher rates in liver-transplant patients compared with the general population. In the era of individualized medicine, this study identifies the highest-risk transplant recipients (PSC and NASH cirrhosis with coexisting HCC/CCA) who may benefit from altered screening practices for these malignancies.

Influence of aspirin on prevention of colorectal cancer: an updated systematic review and meta-analysis of randomized controlled trials

PURPOSE

Colorectal cancer is the second most common cause of cancer death worldwide. Aspirin, due to its antineoplastic effects, has been suggested to have chemopreventive effects on colorectal cancer based on recent trials. We conducted this systematic review and meta-analysis to provide an updated evidence about the long-term efficacy of daily aspirin use in the prevention of colorectal cancer.

METHODS

We searched Medline/PubMed, Ovid, Web of Science, and Cochrane Library. We included randomized controlled trials (RCTs) that compared the efficacy of daily aspirin use to placebo in healthy individuals at the time of study entry. The desired outcomes of this review were the incidence of advanced lesions (i.e., adenomas with villous component, adenomas ≥1 cm in diameter, adenomas with high-grade dysplasia, and/or invasive cancer) and colorectal adenomas.

RESULTS

A total of 15 articles representing 11 RCTs were included. Overall, the results indicated that aspirin significantly reduced the risk of developing colorectal adenomas but not advanced lesions at 3 years (risk ratio (RR) = 0.84, P < 0.05 and risk ratio = 0.82, P = 0.10, respectively). At 5 years, the risk of advanced lesions but not adenomas was reduced by aspirin (RR = 0.68, P < 0.05 and RR = 0.87, P = 0.22, respectively). Aspirin was not found to have an effect on the risk of advanced lesions or adenomas beyond 5 years (hazard ratio (HR) = 0.82, P = 0.07 and HR = 0.99, P = 0.82, respectively).

CONCLUSION

Overall, aspirin (particularly high dose) only reduced the risk of advanced lesions up to 5 years.

Use of ambient lighting during colonoscopy and its effect on adenoma detection rate and eye fatigue: results of a pilot study

Background and study aims  Adenoma detection rate (ADR) appears to decrease as the number of consecutive hours performing procedures increases, and eye strain may be a contributing factor. Ambient light may improve symptoms of eye strain, but its effects have yet to be explored in the field of gastroenterology. We aim to determine if using ambient lighting during screening colonoscopy will maintain ADRs and improve eye strain symptoms compared with low lighting. Methods  At a single center, retrospective data were collected on colonoscopies performed under low lighting and compared to prospective data collected on colonoscopies with ambient lighting. Eye fatigue surveys were completed by gastroenterologists. Satisfaction surveys were completed by physicians and staff. Results  Of 498 low light and 611 ambient light cases, 172 and 220 adenomas were detected, respectively ( P  = 0.611). Under low lighting, the ADR decreased 5.6 % from first to last case of the day ( P  = 0.2658). With ambient lighting, the ADR increased by 2.80 % ( P  = 0.5445). The difference in the overall change in ADR between first and last cases with ambient light versus low light was statistically significant (8.40 % total unit change, P  = 0.01). The average eye strain scores were 8.12 with low light, and 5.63 with ambient light ( P  = 0.3341). Conclusions  Performing screening colonoscopies with ambient light may improve the differential change in ADR that occurs from the beginning to the end of the day. This improvement in ADR may be related to improvement in operator fatigue. The effect of ambient light on eye strain is unclear. Further investigation is warranted on the impact of ambient light on symptoms of eye strain and ADR.

Microsimulation Model to Determine the Cost-Effectiveness of Treat-to-Target Strategies for Ulcerative Colitis

BACKGROUND & AIMS

Little is known about the cost effectiveness of endoscopy or biomarker-based treat to target monitoring of patients with ulcerative colitis (UC).

METHODS

We used a microsimulation model to identify the most cost effective treat to target monitoring strategy for patients with UC staring therapy with biologics or small molecule inhibitors. We assessed symptoms (rectal bleeding) alone, a combination of symptoms and a biomarker (fecal calprotectin), and endoscopy. Transition probabilities, costs, and quality-adjusted life year (QALY) estimates were derived from published estimates. The microsimulation model tracked an individual patient's disease course and treatment exposures to modify downstream treatment effectiveness, probabilities, and disease outcomes. The primary analysis included 100,000 individuals over 5 years with a willingness to pay threshold of $100,000/QALY. Probabilistic sensitivity analyses were performed with 500 samples and 250 trials, in addition to multiple 1-, 2-, and 3-way microsimulation sensitivity analyses.

RESULTS

A total of 32 treatment sequencing algorithms were modeled alongside 3 disease monitoring strategies within a treat to target approach for UC. Combination symptom and biomarker-based monitoring resulted in the highest QALY estimate among all the treatment sequencing algorithms. However, monitoring disease activity with symptoms alone was the most cost-effective strategy in 86% of scenarios, followed by combination symptom and biomarker monitoring in 9%, and endoscopy monitoring in 5%. Results were sensitive to treatment costs, patient willingness to consider colectomy as a treatment option, and endoscopy costs. Endoscopy-based monitoring was favored when treatment costs were high and patients were unwilling to undergo colectomy.

CONCLUSIONS

The combination symptom and biomarker-based monitoring resulted in the highest QALY estimate. However, symptom-based monitoring is the most cost-effective approach to implementing treat to target monitoring for patients with UC receiving biologics and small molecule inhibitors.

Strong Reduction of Colorectal Cancer Incidence and Mortality After Screening Colonoscopy: Prospective Cohort Study From Germany

INTRODUCTION

A claimed advantage of colonoscopy over sigmoidoscopy in colorectal cancer (CRC) screening is prevention of CRC not only in the distal colon and rectum but also in the proximal colon. We aimed to assess the association of screening colonoscopy use with overall and site-specific CRC incidence and associated mortality.

METHODS

Information on use of screening colonoscopy as well as potential confounding factors was obtained at baseline in 2000-2002, updated at 2-, 5-, 8-, and 17-year follow-up from 9,207 participants aged 50-75 years without history of CRC in a statewide cohort study in Saarland, Germany. Covariate-adjusted associations of screening colonoscopy with CRC incidence and mortality, which were obtained through record linkage with the Saarland Cancer Registry and mortality statistics up to 2018, were assessed by Cox proportional hazards models with time-varying exposure information.

RESULTS

During a median follow-up of 17.2 years, 268 participants were diagnosed with CRC and 98 died from CRC. Screening colonoscopy was associated with strongly reduced CRC incidence (adjusted hazard ratio [aHR] 0.44, 95% confidence interval [CI] 0.33-0.57) and mortality (aHR 0.34, 95% CI 0.21-0.53), with stronger reduction for distal (aHRs 0.36, 95% CI 0.25-0.51, and 0.33, 95% CI 0.19-0.59, respectively) than for proximal cancer (aHRs 0.69, 95% CI 0.42-1.13, and 0.62, 95% CI 0.26-1.45, respectively). Nevertheless, strong reduction of mortality from proximal cancer was also observed within 10 years after screening colonoscopy (aHR 0.31, 95% CI 0.10-0.96).

DISCUSSION

In this large prospective cohort study from Germany, screening colonoscopy was associated with strong reduction in CRC incidence and mortality.

Colorectal Cancer Screening and Surveillance for Non-Hereditary High-Risk Groups—Is It Time for a Re-Think?

Purpose of review

Colorectal cancer (CRC) is the second most common cause of cancer death worldwide, killing approximately 900,000 people each year. An individual’s risk of developing CRC is multi-factorial with known risk factors including increasing age, male sex, family history of CRC and raised body mass index. Population-based screening programmes for CRC exist in many countries, and in the United Kingdom (UK), screening is performed through the NHS Bowel Cancer Screening Programme (BCSP). Screening programmes offer a population-based approach for those at “average risk”, and do not typically offer enhanced screening for groups at increased risk. In the UK, such patients are managed via non-screening symptomatic services but in a non-systematic way.

Recent findings

There is growing evidence that conditions such as cystic fibrosis and a history of childhood cancer are associated with higher risk of CRC, and surveillance of these groups is advocated by some organizations; however, national recommendations do not exist in most countries.

Summary

We review the evidence for screening “high risk” groups not covered within most guidelines and discuss health economic issues requiring consideration acknowledging that the demand on colonoscopy services is already overwhelming.

Population-Based Prostate Cancer Screening With Magnetic Resonance Imaging or Ultrasonography: The IP1-PROSTAGRAM Study

Question

In men invited to undergo screening for prostate cancer with magnetic resonance imaging (MRI), ultrasonography, and prostate-specific antigen testing, what is the prevalence of positive test results, rates of biopsy, and detection of prostate cancer?

Findings

In this cohort study in which 408 men underwent 3 screening tests, an MRI score of 4 or 5 was associated with improved detection of clinically significant prostate cancer without an increase in the number of men who underwent biopsy or were overdiagnosed with clinically insignificant prostate cancer if prostate-specific antigen testing alone was used. Ultrasonography was not associated with improved screening performance.

Meaning

These findings suggest that a short, noncontrast MRI may have favorable performance characteristics as a community-based screening test.

Importance

Screening for prostate cancer using prostate-specific antigen (PSA) testing can lead to problems of underdiagnosis and overdiagnosis. Short, noncontrast magnetic resonance imaging (MRI) or transrectal ultrasonography might overcome these limitations.

Objective

To compare the performance of PSA testing, MRI, and ultrasonography as screening tests for prostate cancer.

Design, Setting, and Participants

This prospective, population-based, blinded cohort study was conducted at 7 primary care practices and 2 imaging centers in the United Kingdom. Men 50 to 69 years of age were invited for prostate cancer screening from October 10, 2018, to May 15, 2019.

Interventions

All participants underwent screening with a PSA test, MRI (T2 weighted and diffusion), and ultrasonography (B-mode and shear wave elastography). The tests were independently interpreted without knowledge of other results. Both imaging tests were reported on a validated 5-point scale of suspicion. If any test result was positive, a systematic 12-core biopsy was performed. Additional image fusion–targeted biopsies were performed if the MRI or ultrasonography results were positive.

Main Outcomes and Measures

The main outcome was the proportion of men with positive MRI or ultrasonography (defined as a score of 3-5 or 4-5) or PSA test (defined as PSA ≥3 μg/L) results. Key secondary outcomes were the number of clinically significant and clinically insignificant cancers detected if each test was used exclusively. Clinically significant cancer was defined as any Gleason score of 3+4 or higher.

Results

A total of 2034 men were invited to participate; of 411 who attended screening, 408 consented to receive all screening tests. The proportion with positive MRI results (score, 3-5) was higher than the proportion with positive PSA test results (72 [17.7%; 95% CI, 14.3%-21.8%] vs 40 [9.9%; 95% CI, 7.3%-13.2%]; P < .001). The proportion with positive ultrasonography results (score, 3-5) was also higher than the proportion of those with positive PSA test results (96 [23.7%; 95% CI, 19.8%-28.1%]; P < .001). For an imaging threshold of score 4 to 5, the proportion with positive MRI results was similar to the proportion with positive PSA test results (43 [10.6%; 95% CI, 7.9%-14.0%]; P = .71), as was the proportion with positive ultrasonography results (52 [12.8%; 95% CI, 9.9%-16.5%]; P = .15). The PSA test (≥3 ng/mL) detected 7 clinically significant cancers, an MRI score of 3 to 5 detected 14 cancers, an MRI score of 4 to 5 detected 11 cancers, an ultrasonography score of 3 to 5 detected 9 cancer, and an ultrasonography score of 4 to 5 detected 4 cancers. Clinically insignificant cancers were diagnosed by PSA testing in 6 cases, by an MRI score of 3 to 5 in 7 cases, an MRI score of 4 to 5 in 5 cases, an ultrasonography score of 3 to 5 in 13 cases, and an ultrasonography score of 4 to 5 in 7 cases.

Conclusions and Relevance

In this cohort study, when screening the general population for prostate cancer, MRI using a score of 4 or 5 to define a positive test result compared with PSA alone at 3 ng/mL or higher was associated with more men diagnosed with clinically significant cancer, without an increase in the number of men advised to undergo biopsy or overdiagnosed with clinically insignificant cancer. There was no evidence that ultrasonography would have better performance compared with PSA testing alone.

The Financial Cost of Interprofessional Ambulatory Training: What's the Bottom Line?

BACKGROUND

Team-based care is recommended as a building block of high-performing primary care but has not been widely adapted in training sites. Cost may be one barrier to a team-based approach.

OBJECTIVE

We quantified incremental annual faculty and staff costs as well as potential cost savings associated with an interprofessional (IP) ambulatory training program compared to a traditional residency clinic at the same site.

METHODS

Cost calculations for the 2017-2018 academic year were made using US Department of Labor median salaries by profession and divided by the number of residents trained per year. Cost implications of lower no-show rates were calculated by multiplying the difference in no-show rate by the number of scheduled appointments, and then by the weighted average of the reimbursement rate.

RESULTS

A total of 1572 arrived appointments were seen by the 10 residents in the IP program compared with 8689 arrived appointments seen by 57 residents in the traditional clinic. The no-show rate was 11.5% (265 of 2311) in the IP program and 19.2% (2532 of 13 154) in the traditional clinic (P < .001). Total cost to the health system through higher staffing needs was $113,897, or $11,390 per trained resident.

CONCLUSIONS

Total costs of the IP model due to higher faculty and staff to resident ratios totaled $11,390 per resident per year. Understanding the faculty and staff costs and potential cost-saving opportunities associated with transformation to an IP model may assist in sustainability.

Colorectal Cancer Risk by Genetic Variants in Populations With and Without Colonoscopy History

Background

Polygenic risk scores (PRS), which are derived from results of large genome-wide association studies, are increasingly propagated for colorectal cancer (CRC) risk stratification. The majority of studies included in the large genome-wide association studies consortia were conducted in the United States and Germany, where colonoscopy with detection and removal of polyps has been widely practiced over the last decades. We aimed to assess if and to what extent the history of colonoscopy with polypectomy may alter metrics of the predictive ability of PRS for CRC risk.

Methods

A PRS based on 140 single nucleotide polymorphisms was compared between 4939 CRC patients and 3797 control persons of the Darmkrebs: Chancen der Verhütung durch Screening (DACHS) study, a population-based case-control study conducted in Germany. Risk discrimination was quantified according to the history of colonoscopy and polypectomy by areas under the curves (AUCs) and their 95% confidence intervals (CIs). All statistical tests were 2-sided.

Results

AUCs and 95% CIs were higher among subjects without previous colonoscopy (AUC = 0.622, 95% CI = 0.606 to 0.639) than among those with previous colonoscopy and polypectomy (AUC = 0.568, 95% CI = 0.536 to 0.601; difference [Δ AUC] = 0.054, P = .004). Such differences were consistently seen in sex-specific groups (women: Δ AUC = 0.073, P = .02; men: Δ AUC = 0.046, P = .048) and age-specific groups (younger than 70 years: Δ AUC = 0.052, P = .07; 70 years or older: Δ AUC = 0.049, P = .045).

Conclusions

Predictive performance of PRS may be underestimated in populations with widespread use of colonoscopy. Future studies using PRS to develop CRC prediction models should carefully consider colonoscopy history to provide more accurate estimates.

Real-world cost-effectiveness of stool-based colorectal cancer screening in a Medicare population

AIM

Multiple screening strategies are guideline-endorsed for average-risk colorectal cancer (CRC). The impact of real-world adherence rates on the cost-effectiveness of non-invasive stool-based CRC screening strategies remains undefined.

METHODS

This cost-effectiveness analysis from the perspective of Medicare as a primary payer used the Colorectal Cancer and Adenoma Incidence and Mortality Microsimulation Model (CRC-AIM) to estimate cost and clinical outcomes for triennial multi-target stool DNA (mt-sDNA), annual fecal immunochemical test (FIT) and annual fecal occult blood test (FOBT) screening strategies in a simulated cohort of US adults aged 65 years, who were assumed to either be previously unscreened or initiating screening upon entry to Medicare. Reported real-world adherence rates for initial stool-based screening and colonoscopy follow up (after a positive stool test result) were defined as 71.1% and 73.0% for mt-sDNA, 42.6% and 47.0% for FIT, and 33.4% and 47.0% for FOBT, respectively. The incremental cost-effectiveness ratio using quality-adjusted life years (QALY) was defined as the primary outcome of interest; other cost and clinical outcomes were also reported in secondary analyses. Multiple sensitivity and scenario analyses were conducted.

RESULTS

When reported real-world adherence rates were included only for initial stool-based screening, mt-sDNA was cost-effective versus FIT ($62,814/QALY) and FOBT ($39,171/QALY); mt-sDNA also yielded improved clinical outcomes. When reported real-world adherence rates were included for both initial stool-based screening and follow-up colonoscopy (when indicated), mt-sDNA was increasingly cost-effective compared to FIT and FOBT ($31,725/QALY and $28,465/QALY, respectively), with further improved clinical outcomes.

LIMITATIONS

Results are based on real-world cross-sectional adherence rates and may vary in the context of other types of settings. Only guideline-recommended stool-based strategies were considered in this analysis.

CONCLUSION

Comparisons of the effectiveness and benefits of specific CRC screening strategies should include both test-specific performance characteristics and real-world adherence to screening tests and, when indicated, follow-up colonoscopy.

Imaging alternatives to colonoscopy: CT colonography and colon capsule. European Society of Gastrointestinal Endoscopy (ESGE) and European Society of Gastrointestinal and Abdominal Radiology (ESGAR) Guideline - Update 2020

1: ESGE/ESGAR recommend computed tomographic colonography (CTC) as the radiological examination of choice for the diagnosis of colorectal neoplasia.Strong recommendation, high quality evidence.ESGE/ESGAR do not recommend barium enema in this setting.Strong recommendation, high quality evidence. 2: ESGE/ESGAR recommend CTC, preferably the same or next day, if colonoscopy is incomplete. The timing depends on an interdisciplinary decision including endoscopic and radiological factors.Strong recommendation, low quality evidence.ESGE/ESGAR suggests that, in centers with expertise in and availability of colon capsule endoscopy (CCE), CCE preferably the same or the next day may be considered if colonoscopy is incomplete.Weak recommendation, low quality evidence. 3: When colonoscopy is contraindicated or not possible, ESGE/ESGAR recommend CTC as an acceptable and equally sensitive alternative for patients with alarm symptoms.Strong recommendation, high quality evidence.Because of lack of direct evidence, ESGE/ESGAR do not recommend CCE in this situation.Very low quality evidence.ESGE/ESGAR recommend CTC as an acceptable alternative to colonoscopy for patients with non-alarm symptoms.Strong recommendation, high quality evidence.In centers with availability, ESGE/ESGAR suggests that CCE may be considered in patients with non-alarm symptoms.Weak recommendation, low quality evidence. 4: Where there is no organized fecal immunochemical test (FIT)-based population colorectal screening program, ESGE/ESGAR recommend CTC as an option for colorectal cancer screening, providing the screenee is adequately informed about test characteristics, benefits, and risks, and depending on local service- and patient-related factors.Strong recommendation, high quality evidence.ESGE/ESGAR do not suggest CCE as a first-line screening test for colorectal cancer.Weak recommendation, low quality evidence. 5: ESGE/ESGAR recommend CTC in the case of a positive fecal occult blood test (FOBT) or FIT with incomplete or unfeasible colonoscopy, within organized population screening programs.Strong recommendation, moderate quality evidence.ESGE/ESGAR also suggest the use of CCE in this setting based on availability.Weak recommendation, moderate quality evidence. 6: ESGE/ESGAR suggest CTC with intravenous contrast medium injection for surveillance after curative-intent resection of colorectal cancer only in patients in whom colonoscopy is contraindicated or unfeasibleWeak recommendation, low quality evidence.There is insufficient evidence to recommend CCE in this setting.Very low quality evidence. 7: ESGE/ESGAR suggest CTC in patients with high risk polyps undergoing surveillance after polypectomy only when colonoscopy is unfeasible.Weak recommendation, low quality evidence.There is insufficient evidence to recommend CCE in post-polypectomy surveillance.Very low quality evidence. 8: ESGE/ESGAR recommend against CTC in patients with acute colonic inflammation and in those who have recently undergone colorectal surgery, pending a multidisciplinary evaluation.Strong recommendation, low quality evidence. 9: ESGE/ESGAR recommend referral for endoscopic polypectomy in patients with at least one polyp ≥ 6 mm detected at CTC or CCE.Follow-up CTC may be clinically considered for 6 - 9-mm CTC-detected lesions if patients do not undergo polypectomy because of patient choice, comorbidity, and/or low risk profile for advanced neoplasia.Strong recommendation, moderate quality evidence.

Modeling costs and benefits of the organized colorectal cancer screening programme and its potential future improvements in Hungary

OBJECTIVE

The national population-based colorectal cancer screening programme in Hungary was initiated in December 2018. We aimed to evaluate the current programme and investigate the costs and benefits of potential future changes to overcome the low coverage of the target population.

METHODS

We performed an economic evaluation from a healthcare payer perspective using an established micro-simulation model (Microsimulation Screening Analysis-Colon). We simulated costs and benefits of screening with fecal immunochemical test in the Hungarian population aged 50-100, investigating also the impact of potential future scenarios which were assumed to increase invitation coverage: improvement of the IT platform currently used by GPs or distributing the tests through pharmacies instead of GPs.

RESULTS

The model predicted that the current screening programme could lead to 6.2% colorectal cancer mortality reduction between 2018 and 2050 compared to no screening. Even higher reductions, up to 16.6%, were estimated when tests were distributed through pharmacies and higher coverage was assumed. This change in the programme was estimated to require up to 26 million performed fecal immunochemical tests and 1 million colonoscopies for the simulated period. These future scenarios have acceptable cost-benefit ratios of €8000-€8700 per life-years gained depending on the assumed adherence of invited individuals.

CONCLUSIONS

With its limitations, the current colorectal cancer screening programme in Hungary will have a modest impact on colorectal cancer mortality. Significant improvements in mortality reduction could be made at acceptable costs, if the tests were to be distributed by pharmacies allowing the entire target population to be invited.

Use of Polygenic Risk Scores to Select Screening Intervals After Negative Findings From Colonoscopy

BACKGROUND & AIMS

Polygenic risk scores (PRSs) could help to define starting ages for colorectal cancer (CRC) screening. However, the role of PRS in determining the length of screening interval after negative findings from colonoscopies is unclear. We aimed to evaluate CRC risk according to PRS and time since last negative colonoscopy.

METHODS

We collected data from 3827 cases and 2641 CRC-free controls in a population-based case-control study in Germany. We constructed a polygenic risk scoring system, based on 90 single-nucleotide polymorphisms, associated with risk of CRC in people of European descent. Participants were classified as having low, medium, or high genetic risk according to tertiles of PRSs among controls. Multiple logistic regression models were used to assess CRC risk according to PRS and time since last negative colonoscopy.

RESULTS

Compared to individuals without colonoscopy in the low PRS category, a 42%-85% lower risk of CRC was observed for individuals who had a negative finding from colonoscopy within 10 years. Beyond 10 years after a negative finding from colonoscopy, significantly lower risk only persisted for the low and medium PRS groups, but not for the high PRS group. Adjusted odds ratios were 0.44 (95% CI, 0.29-0.68), 0.51 (95% CI, 0.34-0.77), and 0.85 (95% CI, 0.58-1.23) in the low, medium, and high PRS group, respectively. Within any time interval, risks were lower for distal than for proximal CRCs.

CONCLUSIONS

Based on findings from a population-based case-control study, the recommended 10-year screening interval for colonoscopy may not need to be shortened among people with high PRSs, but could potentially be prolonged for people with low and medium PRSs. Studies are needed to address personalized time intervals for repeat colonoscopies in average-risk screening cohorts.

The Impact of COVID-19 on Cancer Screening: Challenges and Opportunities

Cancer is a leading cause of death in the United States and across the globe. Cancer screening is an effective preventive measure that can reduce cancer incidence and mortality. While cancer screening is integral to cancer control and prevention, due to the COVID-19 outbreak many screenings have either been canceled or postponed, leaving a vast number of patients without access to recommended health care services. This disruption to cancer screening services may have a significant impact on patients, health care practitioners, and health systems. In this paper, we aim to offer a comprehensive view of the impact of COVID-19 on cancer screening. We present the challenges COVID-19 has exerted on patients, health care practitioners, and health systems as well as potential opportunities that could help address these challenges.

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.

Preventing Breast, Cervical, and Colorectal Cancer Deaths: Assessing the Impact of Increased Screening

Introduction

The US Preventive Services Task Force (USPSTF) recommends select preventive clinical services, including cancer screening. However, screening for cancers remains underutilized in the United States. The Centers for Disease Control and Prevention leads initiatives to increase breast, cervical, and colorectal cancer (CRC) screening. We assessed the number of avoidable deaths from increased screening, according to USPSTF recommendations, for CRC and female breast and cervical cancers.

Methods

We used model-based estimates of avoidable deaths for the lifetime of single-year age cohorts under the current and increased use of screening scenarios (data year 2016; analysis, 2018). We calculated prevented cancer deaths for each 1% increase in screening uptake and extrapolated to current level of screening (2016), current level plus 10 percentage points, and increasing screening to 90% and 100% of the eligible population.

Results

Increased use of screening from current levels to 100% would prevent an additional 2,821 deaths from breast cancer, 6,834 deaths from cervical cancer, and 35,530 deaths from CRC over a lifetime of the respective single-year cohort. Increasing use of CRC screening would prevent approximately 8.5 times as many deaths as the equivalent increase in use of breast cancer screening (women only), although twice as many people (men and women) would have to be screened for CRC.

Conclusions

A large number of deaths could be avoided by increasing breast, cervical, and CRC screening. Public health programs incorporating strategies shown to be effective can help increase screening rates.

The health belief model and colorectal cancer screening in the general population: A systematic review

Colorectal cancer screening saves lives and is cost-effective. It allows early detection of the pathology, and enables earlier medical intervention. Despite clinical practice guidelines promoting screening for average risk individuals, uptake remains suboptimal in many populations. Few studies have examined how sociobehavioural factors influence screening uptake in the context of behaviour change theories such as the health belief model. This systematic review therefore examines how the health belief model’s constructs are associated with colorectal cancer screening.

Four databases were systematically searched from inception to September 2019. Quantitative observational studies that used the health belief model to examine colorectal screening history, intention or behaviour were included.

A total of 30 studies met the criteria for review; all were of cross-sectional design. Perceived susceptibility, benefits and cues to action were directly associated with screening history or intention. Perceived barriers inversely associated with screening history or intention. The studies included also found other modifying factors including sociodemographic and cultural norms. Self-report of screening history, intention or behaviour, convenience sampling and lack of temporality among factors were common limitations across studies.

The health belief model’s associations with colorectal cancer screening uptake was consistent with preventive health behaviours in general. Future studies should examine how theory-based behavioural interventions can be tailored to account for the influence of socioecological factors.

Educational interventions are associated with improvements in colonoscopy quality indicators: a systematic review and meta-analysis

Background and study aims  The quality of screening-related colonoscopy depends on several physician- and patient-related factors. Adenoma detection rate (ADR) varies considerably between endoscopists. Educational interventions aim to improve endoscopists' ADRs, but their overall impact is uncertain. We aimed to assess whether there is an association between educational interventions and colonoscopy quality indicators. Methods  A comprehensive search was performed through August 2019 for studies reporting any associations between educational interventions and any colonoscopy quality indicators. Our primary outcome of interest was ADR. Two authors assessed eligibility criteria and extracted data independently. Risk of bias was also assessed for included studies. Pooled rate ratios (RR) with 95 % confidence intervals (CI) were reported using DerSimonian and Laird random effects models. Results  From 2,253 initial studies, eight were included in the meta-analysis for ADR, representing 86,008 colonoscopies. Educational interventions were associated with improvements in overall ADR (RR 1.29, 95 % CI 1.25 to 1.42, 95 % prediction interval 1.09 to 1.53) and proximal ADR (RR 1.39, 95 % CI 1.29 to 1.48), with borderline increases in withdrawal time, ([WT], mean difference 0.29 minutes, 95 % CI - 0.12 to 0.70 minutes). Educational interventions did not affect cecal intubation rate ([CIR], RR 1.01, 95 % CI 1.00 to 1.01). Heterogeneity was considerable across many of the analyses. Conclusions  Educational interventions are associated with significant improvements in ADR, in particular, proximal ADR, and are not associated with improvements in WT or CIR. Educational interventions should be considered an important option in quality improvement programs aiming to optimize the performance of screening-related colonoscopy.

Cecal intubation time between the use of one-channel and two-channel water exchange colonoscopy: A randomized controlled trial

BACKGROUND AND AIM

Water exchange (WE) colonoscopy is the least painful insertion technique with high adenoma detection rate but requires a longer intubation time. In the published literature, some investigators used the instrument channel for both infusing and suctioning of water (one channel), while others use colonoscopes with an integrated water-jet channel specifically designed for infusing water (two channel). The aim of this study was to compare cecal intubation time between one-channel and two-channel WE.

METHODS

A total 120 patients undergoing colonoscopy from May 2017 to April 2019 at a regional hospital in southern Taiwan were randomized to either a two-channel group (n = 60) or a one-channel group (n = 60). The primary outcome was cecal intubation time.

RESULTS

The mean cecal intubation time was significantly shorter in the two-channel group compared with the one-channel group (14.0 ± 4.0 vs 17.4 ± 6.7 min, P < 0.001). The two-channel group required less water infused during insertion (564.8 ± 232.4 vs 1213.3 ± 467.5 mL, P < 0.001) but achieved a significantly higher Boston Bowel Preparation Scale score (8.4 ± 0.8 vs 7.5 ± 1.1, P < 0.001) than did the one-channel group. The adenoma detection rate was comparable in the two groups (50.0% vs 48.3%, P = 0.855).

CONCLUSIONS

In comparison with the one-channel WE, two-channel WE showed a shorter cecal intubation time, required less amount of water during insertion, and provided a better salvage cleansing effect. (NCT03279705).

Conventional Computed Tomographic Calcium Scoring vs full chest CTCS for lung cancer screening: a cost-effectiveness analysis

Background

Conventional CTCS images the mid/lower chest for coronary artery disease (CAD). Because many CAD patients are also at risk for lung malignancy, CTCS often discovers incidental pulmonary nodules (IPN). CTCS excludes the upper chest, where malignancy is common. Full-chest CTCS (FCT) may be a cost-effective screening tool for IPN.

Methods

A decision tree was created to compare a FCT to CTCS in a hypothetical patient cohort with suspected CAD. (Figure) The design compares the effects of missed cancers on CTCS with the cost of working up non-malignant nodules on FCT. The model was informed by results of the National Lung Screening Trial and literature review, including the rate of malignancy among patients receiving CTCS and the rate of malignancy in upper vs lower portions of the lung. The analysis outcomes are Quality-Adjusted Life Year (QALY) and incremental cost-effectiveness ratio (ICER), which is generally considered beneficial when <$50,000/QALY.

Results

Literature review suggests that rate of IPNs in the upper portion of the lung varied from 47 to 76%. Our model assumed that IPNs occur in upper and lower portions of the lung with equal frequency. The model also assumes an equal malignancy potential in upper lung IPNs despite data that malignancy occurs 61–66% in upper lung fields.

In the base case analysis, a FCT will lead to an increase of 0.03 QALYs comparing to conventional CTCS (14.54 vs 14.51 QALY, respectively), which translates into an QALY increase of 16 days. The associated incremental cost for FCT is $278 ($1027 vs $748, FCT vs CTCS respectively. The incremental cost-effectiveness ratio (ICER) is $10,289/QALY, suggesting significant benefit. Sensitivity analysis shows this benefit increases proportional to the rate of malignancy in upper lung fields.

Conclusion

Conventional CTCS may be a missed opportunity to screen for upper lung field cancers in high risk patients. The ICER of FCT is better than screening for breast cancer screening (mammograms $80 k/QALY) and colon cancer (colonoscopy $6 k/QALY). Prospective studies are appropriate to define protocols for FCT.

Cost-Effectiveness of Current Colorectal Cancer Screening Tests

Cost-effectiveness analysis compares benefits and costs of different interventions to inform decision makers. Alternatives are compared based on an incremental cost-effectiveness ratio reported in terms of cost per quality-adjusted life-year gained. Multiple cost-effectiveness analyses of colorectal cancer (CRC) screening have been performed. Although regional epidemiology of CRC, relevant screening strategies, regional health system, and applicable medical costs in local currencies differ by country and region, several overarching points emerge from literature on cost-effectiveness of CRC screening. Cost-effectiveness analysis informs decisions in ongoing debates, including preferred age to begin average-risk CRC screening, and implementation of CRC screening tailored to predicted CRC risk.

Impact of new techniques on adenoma detection rate based on meta-analysis data

The high incidence of colorectal cancer and the occurrence of interval cancers after screening colonoscopy support the need to develop methods to increase adenoma detection rate (ADR). This review focuses on the importance of ADR and the impact of new techniques on ADR based on meta-analysis data. The low-cost interventions (such as water-aided colonoscopy, second observation, and dynamic position change) were effective in increasing ADR. So were enhanced imaging techniques and add-on devices. Increase with higher cost interventions such as newer scopes is uncertain. Water exchange (WE) has the highest ADR compared with water immersion, air insufflation, and carbon dioxide insufflation. Second observation with forward or retroflexed views improved the right colon ADR. Add-on devices result in only modest improvement in ADR, of particular help in low performing endoscopists. The second-generation narrow-band imaging (NBI) provided a two-fold brighter image than the previous system. The improvement in ADR with NBI required the "best" quality bowel preparation. New endoscopic techniques incur various additional costs, nil for WE, small for tip attachments but large for the newer scopes. In conclusion, one or more of the above methods to improve ADR may be applicable in Taiwan. A comparison of these approaches to determine which is the most cost-effective is warranted.

Efficacy and cost-effectiveness of fecal immunochemical test versus colonoscopy in colorectal cancer screening: a systematic review and meta-analysis

BACKGROUND AND AIMS

The fecal immunochemical test (FIT) and colonoscopy are the most commonly used strategies for colorectal cancer (CRC) screening worldwide. We aimed to compare their efficacy and cost-effectiveness in CRC screening in an average-risk population.

METHODS

PubMed, Embase, and National Health Services Economic Evaluation Database were searched. Risk ratio (RR) was used to evaluate the differences in detection rates of colorectal neoplasia between FIT and colonoscopy groups. A random-effects model was used to pool RRs. Incremental cost-effectiveness ratios (ICERs) were calculated to evaluate the cost-effectiveness of FIT versus colonoscopy.

RESULTS

Six randomized controlled trials and 17 cost-effectiveness studies were included. The participation rate in the FIT group was higher than that in the colonoscopy group (41.6% vs 21.9%). In the intention-to-treat analysis, FIT had a detection rate of CRC comparable with colonoscopy (RR, .73; 95% confidence interval, .37-1.42) and lower detection rates of any adenoma and advanced adenoma than 1-time colonoscopy. Most included cost-effectiveness studies showed that annual (13/15) or biennial (5/6) FIT was cost-saving (ICER < $0) or very cost-effective ($0 < ICER ≤ $25000/quality-adjusted life-year) compared with colonoscopy every 10 years.

CONCLUSIONS

FIT may be similar to 1-time colonoscopy in the detection rate of CRC, although it has lower detection rates of any adenoma and advanced adenoma than 1-time colonoscopy. Furthermore, annual or biennial FIT appears to be very cost-effective or cost-saving compared with colonoscopy every 10 years. These findings indicate, at least partly, that FIT is noninferior to colonoscopy in CRC screening in an average-risk population. Our findings should be treated with caution and need to be further confirmed.

Cost-utility of colorectal cancer screening at 40 years old for average-risk patients

The incidence of colorectal cancer (CRC) is increasing in patients under the age of 50. The purpose of this study was to assess the cost-utility of available screening modalities starting at 40 years in the general population compared to standard screening at 50 years old. A decision tree modeling average-risk of CRC in the United States population was constructed for the cost per quality-adjusted life year (QALY) of the five most common and effective CRC screening modalities in average-risk 40-year olds versus deferring screening until 50 years old (standard of care) under a limited societal perspective. All parameters were derived from existing literature. We evaluated the incremental cost-utility ratio of each comparator at a willingness-to-pay threshold of $50,000/QALY and included multivariable probabilistic sensitivity analysis. All screening modalities assessed were more cost-effective with increased QALYs than current standard care (no screening until 50). The most favorable intervention by net monetary benefit was flexible sigmoidoscopy ($3284 per person). Flexible sigmoidoscopy, FOBT, and FIT all dominated the current standard of care. Colonoscopy and FIT-DNA were both cost-effective (respectively, $4777 and $11,532 per QALY). The cost-effective favorability of flexible sigmoidoscopy diminished relative to colonoscopy with increasing willingness-to-pay. Regardless of screening modality, CRC screening at 40 years old is cost-effective with increased QALYs compared to current screening initiation at 50 years old, with flexible sigmoidoscopy most preferred. Consideration should be given for a general recommendation to start screening at age 40 for average risk individuals.

Strategies for Colorectal Cancer Screening

The incidence of colorectal cancer (CRC) is increasing worldwide. CRC has high mortality when detected at advanced stages, yet it is also highly preventable. Given the difficulties in implementing major lifestyle changes or widespread primary prevention strategies to decrease CRC risk, screening is the most powerful public health tool to reduce mortality. Screening methods are effective but have limitations. Furthermore, many screen-eligible people remain unscreened. We discuss established and emerging screening methods, and potential strategies to address current limitations in CRC screening. A quantum step in CRC prevention might come with the development of new screening strategies, but great gains can be made by deploying the available CRC screening modalities in ways that optimize outcomes while making judicious use of resources.

Economic evaluations of screening strategies for the early detection of colorectal cancer in the average-risk population: A systematic literature review

Background

Colorectal cancer (CRC) screening has proven effective in reducing CRC mortality. This study aimed to systematically review, and evaluate the reporting quality, of the economic evidence regarding CRC screening in average-risk individuals.

Methods

Databases searched included Medline, EMBASE, National Health Service Economic Evaluation, Database of Abstracts of Reviews of Effects, Cost-Effectiveness Analysis registry, EconLit, and Health Technology Assessment database. Eligible studies were cost-effectiveness and cost-utility analyses comparing CRC screening strategies in average-risk individuals, published in English or Spanish, between January 2012 and November 2018. Reporting quality was assessed using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist.

Results

Of 1,993 publications initially retrieved, 477 were excluded by duplicate review, 1,449 by title/abstract review, and 34 by full-text review. Finally, 33 publications were included in the qualitative synthesis. Most studies were conducted in Europe (36,4%), followed by United States (24,2%) and Asia (24,2%). The main screening modalities considered were fecal immunochemical tests (70%), colonoscopy (67%), guaiac fecal occult blood test (42%) and flexible sigmoidoscopy (30%). In most studies, CRC screening was deemed cost-effective compared to no screening. Sensitivity analyses indicated that cost of CRC screening tests, adherence to screening, screening test sensitivity, and cost of CRC treatment had the greatest impact on cost-effectiveness results across studies. The majority of studies (73%) adequately reported at least 50% of the items included in the CHEERS checklist. Least well reported items included setting, study perspective, discount rate, model choice, and methods to identify effectiveness data or to estimate resource use and costs.

Conclusions

CRC screening is an efficient alternative to no screening. Nevertheless, it is not possible to conclude which strategy should be preferred for population-based screening programs. Although we observed an overall good adherence to CHEERS recommendations, there is still room for improvement in economic evaluations reporting in this field.

Effectiveness, benefit harm and cost effectiveness of colorectal cancer screening in Austria

BACKGROUND

Clear evidence on the benefit-harm balance and cost effectiveness of population-based screening for colorectal cancer (CRC) is missing. We aim to systematically evaluate the long-term effectiveness, harms and cost effectiveness of different organized CRC screening strategies in Austria.

METHODS

A decision-analytic cohort simulation model for colorectal adenoma and cancer with a lifelong time horizon was developed, calibrated to the Austrian epidemiological setting and validated against observed data. We compared four strategies: 1) No Screening, 2) FIT: annual immunochemical fecal occult blood test age 40-75 years, 3) gFOBT: annual guaiac-based fecal occult blood test age 40-75 years, and 4) COL: 10-yearly colonoscopy age 50-70 years. Predicted outcomes included: benefits expressed as life-years gained [LYG], CRC-related deaths avoided and CRC cases avoided; harms as additional complications due to colonoscopy (physical harm) and positive test results (psychological harm); and lifetime costs. Tradeoffs were expressed as incremental harm-benefit ratios (IHBR, incremental positive test results per LYG) and incremental cost-effectiveness ratios [ICER]. The perspective of the Austrian public health care system was adopted. Comprehensive sensitivity analyses were performed to assess uncertainty.

RESULTS

The most effective strategies were FIT and COL. gFOBT was less effective and more costly than FIT. Moving from COL to FIT results in an incremental unintended psychological harm of 16 additional positive test results to gain one life-year. COL was cost saving compared to No Screening. Moving from COL to FIT has an ICER of 15,000 EUR per LYG.

CONCLUSIONS

Organized CRC-screening with annual FIT or 10-yearly colonoscopy is most effective. The choice between these two options depends on the individual preferences and benefit-harm tradeoffs of screening candidates.

Comparison of the participation rate between CT colonography and colonoscopy in screening population: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To compare the participation rate between CT colonography (CTC) and colonoscopy in screening population in randomized controlled trials (RCTs).

METHODS

A search was performed using the PubMed, Web of Science, and Cochrane databases. RCTs that included screening populations and reported participation number were assessed. Cochrane risk of bias tool was used to assess the bias and quality. Risk ratio (RR) was used to present the results. The non-participation rate was analyzed to verify the results of participation rate.

RESULTS

Five of 760 studies, with a total of 15,974 invitees, were included. The participation rate was higher at CTC (28.8%) than colonoscopy (20.8%), although the difference did not reach statistical significance (RR = 1.26; p = 0.070; I² = 90.3%). The non-participation rate at CTC was significantly lower than colonoscopy (RR = 0.92; p = 0.012; I² = 86.7%). Subgroup analysis suggested both the participation and non-participation rate were with significant difference between reduced/no cathartic preparation CTC and colonoscopy. Cumulative meta-analysis showed both the participation rate and non-participation rate exhibited a trend over time and sample size.

CONCLUSION

The participation rate was higher at CTC than colonoscopy, although the difference did not reach statistical significance. But the non-participation rate was with statistical difference. Screening population seemed more likely to participate the reduced/no cathartic preparation CTC. Statistical evidence was provided for more large RCTs are needed in the future.

ADVANCES IN KNOWLEDGE

The screening populations seem more likely to participate in the CTC, especially the reduced/no cathartic preparation CTC. The statistical evidence was provided for more large RCTs are needed in the future.

Long noncoding RNA LINC02418 regulates MELK expression by acting as a ceRNA and may serve as a diagnostic marker for colorectal cancer

Some types of long noncoding RNAs (lncRNAs) are aberrantly expressed in human diseases, including cancer. However, the overall biological roles and clinical significances of most lncRNAs in colorectal cancer (CRC) are not fully understood. First, The Cancer Genome Atlas (TCGA) was analyzed to identify differentially expressed lncRNAs between CRC tissues and noncancerous tissues. We identified that LINC02418 was highly expressed in CRC tissues and cell lines. Next, we evaluated the effect of LINC02418 on CRC tumorigenesis and its regulatory functions of absorbing microRNA and indirectly stimulating protein expression by acting as a ceRNA. Mechanistically, LINC02418 acted as a ceRNA to upregulate MELK expression by absorbing miR-1273g-3p. In addition, the diagnostic performance of cell-free LINC02418 and exosomal LINC02418 were both evaluated by the receiver operating characteristic curve and the area under the curve (AUC). Exosomal LINC02418 could distinguish the patients with CRC from the healthy controls (AUC = 0.8978, 95% confidence interval = 0.8644–0.9351) better than cell-free LINC02418 (AUC = 0.6784, 95% confidence interval = 0.6116–0.7452). Collectively, we determined that LINC02418 was significantly overexpressed in CRC and that the LINC02418–miR-1273g-3p–MELK axis played a critical role in CRC tumorigenesis. Finally, exosomal LINC02418 is a promising, novel biomarker that can be used for the clinical diagnosis of CRC.