Sorting out measures and definitions of screening participation to improve comparability: The example of colorectal cancer

Coverage by examinations associated with early detection of colorectal neoplasia in the Czech Republic

BACKGROUND

Coverage by examinations is a crucial indicator of the future impact on the burden of colorectal cancer (CRC). The study aimed to evaluate coverage by examinations associated with CRC screening and early cancer detection of CRC in the Czech Republic. The burden of CRC was also assessed.

METHODS

The novel nationwide administrative registry with individual data (period 2010-19) was used to evaluate coverage by examinations for screening faecal occult blood test and colonoscopy. In the second step, additional examinations for early CRC detection were included in the coverage calculation (complete coverage). Age-specific trends in CRC incidence (period 1977-2018) were investigated using Joinpoint regression.

RESULTS

Coverage by screening examinations within recommended interval was around 30%. Complete coverage reached >37% and >50% at the 3-year interval. The coverage by examinations for the non-screening population aged 40-49 years was almost 4% and 5% (most of them were colonoscopies) at the 3-year interval. In age groups aged ≥50 years, we observed a significant annual decline, especially in the 50-69 age group, with recent annual decreases reaching up to 5-7%. The change in trend and the recent decline were also observed in the age group 40-49.

CONCLUSIONS

More than half of the target screening population was covered by examinations potentially associated with early detection and subsequent treatment of colorectal neoplasms. The substantial coverage by potentially prophylactic examinations might be an explanation for the considerable decrease in CRC incidence.

Guidance for setting international standards on reporting longitudinal adherence to stool-based colorectal cancer screening

Longitudinal adherence to colorectal cancer (CRC) screening is reported using different summarizing measures, which hampers international comparison. We provide evidence to guide recommendations on which longitudinal adherence measure to report. Using adherence data over four stool-based CRC screening rounds in three countries, we calculated six summarizing adherence measures; adherence over all rounds, adherence per round, rescreening, full programme adherence (yes/no), regularity (never/inconsistent/consistent screenees) and number of times participated. For each measure, we calculated the accuracy in capturing the observed adherence patterns. Using the ASCCA model, we predicted screening effectiveness when using summarizing measures as model input versus the observed adherence patterns. Adherence over all rounds in the Italian, Spanish and Dutch cohorts was 64.9%, 42.8% and 61.5%, respectively, and the proportion of consistent screenees was 50.9%, 26.3% and 45.7%. Number of times participated and regularity were most accurate and resulted in similar model-predicted screening effectiveness as simulating the observed adherence patterns of Italy, Spain and the Netherlands (mortality reductions: 24.4%, 16.9% and 23.5%). Adherence over all rounds and adherence per round were least accurate. Screening effectiveness was overestimated when using adherence over all rounds (mortality reductions: 26.8%, 19.4% and 25.7%) and adherence per round (mortality reductions: 26.8%, 19.5% and 25.9%). To conclude, number of times participated and regularity were most accurate and resulted in similar model-predicted screening effectiveness as using the observed adherence patterns. However they require longitudinal data. To facilitate international comparison of CRC screening programme performance, consensus on an accurate adherence measure to report should be reached.

Effect of Chronic Comorbidities on Follow-up Colonoscopy After Positive Colorectal Cancer Screening Results: A Population-Based Cohort Study

INTRODUCTION

Fecal occult blood tests (FOBTs) are colorectal cancer screening tests used to identify individuals requiring further investigation with colonoscopy. Delayed colonoscopy after positive FOBT (FOBT+) is associated with poorer cancer outcomes. We assessed the effect of comorbidity on colonoscopy receipt within 12 months after FOBT+.

METHODS

Population-based healthcare databases from Ontario, Canada, were linked to assemble a cohort of 50-74-year-old individuals with FOBT+ results between 2008 and 2017. The associations between comorbidities and colonoscopy receipt within 12 months after FOBT+ were examined using multivariable cause-specific hazard regression models.

RESULTS

Of 168,701 individuals with FOBT+, 80.5% received colonoscopy within 12 months. In multivariable models, renal failure (hazard ratio [HR] 0.71, 95% confidence interval [CI] 0.62-0.82), heart failure (HR 0.77, CI 0.75-0.80), and serious mental illness (HR 0.88, CI 0.85-0.92) were associated with the lowest colonoscopy rates, compared with not having each condition. The number of medical conditions was inversely associated with colonoscopy uptake (≥4 vs 0: HR 0.64, CI 0.58-0.69; 3 vs 0: HR 0.75, CI 0.72-0.78; and 2 vs 0: HR 0.87, CI 0.85-0.89). Having both medical and mental health conditions was associated with a lower colonoscopy uptake relative to no comorbidity (HR 0.88, CI 0.87-0.90).

DISCUSSION

Persons with medical and mental health conditions had lower colonoscopy rates after FOBT+ than those without these conditions. Better strategies are needed to optimize colorectal cancer screening and follow-up in individuals with comorbidities.

The association between adherence to cancer screening programs and health literacy: A systematic review and meta-analysis

The effectiveness of a cancer screening program relies on its adherence rate. Health literacy (HL) has been investigated among the factors that could influence such participation, but the findings are not always consistent. The aim of this meta-analysis was to summarize the evidence between having an adequate level of HL (AHL) and adherence to cancer screening programs. PubMed, Scopus, and Web of Science were searched. Cross-sectional studies, conducted in any country, that provided raw data, unadjusted or adjusted odds ratio (OR) on the associations of interest were included. The quality of the studies was assessed with the Newcastle-Ottawa Scale. Inverse-variance random effects methods were used to produce pooled ORs and their associated confidence interval (CI) stratified by time interval (e.g., undergoing screening in the last period, or at least once during lifetime) for each cancer type, considering unadjusted and adjusted estimates separately. A sensitivity analysis was performed for those studies providing more estimates. Overall, 15 articles of average-to-good quality were pooled. We found a significant association between AHL and higher screening participation for breast, cervical and colorectal cancer, independently of other factors, both overall (N = 7, aOR = 1.73; 95% CI: 1.27-2.36; N = 3, aOR = 1.64; 95% CI: 1.30-2.09; and N = 5, aOR = 1.25, 95% CI: 1.12-1.39, respectively) and in most time-stratified analyses. The sensitivity analyses confirmed these results. Health literacy seems to be critical for an effective cancer prevention. Given the high prevalence of illiterate people across the world, a long-term action plan is needed.

Breast and cervical cancer screening attendance among Czech women

OBJECTIVES

The aim of the study was to investigate the variation in breast and cervical cancer screening attendance among Czech women by age and in regions in 2009-2017.

METHODS

The data from the health insurance company that covers around 50% of the Czech population were used to calculate age-specific attendance rates and standardized attendance rates by year and region.

RESULTS

In 2017, the attendance of all eligible women was 52% in breast cancer screening and 46% in cervical cancer screening. There were differences in attendance among groups of women. Women aged 45-49 had attendance rates in both screenings around 60%, while 39% of women aged 75-79 attended breast cancer screening, and 23% attended cervical cancer screening. In regions, attendance ranged from 38% to 70% in breast cancer screening and from 32% to 55% in cervical cancer screening.

CONCLUSIONS

We identified the age-specific differences and regional variation in both breast and cervical cancer screening attendance among Czech women. Those with lower attendance may have a higher risk of dying from breast and cervical cancers. Mitigating this risk should be a priority of public health policies.

Measures of longitudinal adherence to fecal-based colorectal cancer screening: Literature review and recommended approaches

The success of fecal occult blood-based colorectal cancer screening programs is dependent on repeating screening at short intervals (ie, every 1-2 years). We conducted a literature review to assess measures that have been used to assess longitudinal adherence to fecal-based screening. Among 46 citations identified and included in this review, six broad classifications of longitudinal adherence were identified: (a) stratified single-round attendance, (b) all possible adherence permutations, (c) consistent/inconsistent/never attendance, (d) number of times attended, (e) program adherence and (f) proportion of time covered. Advantages and disadvantages of these measures are described, and recommendations on which measures to use based on data availability and scientific question are also given. Stratified single round attendance is particularly useful for describing the yield of screening, while programmatic adherence measures are best suited to evaluating screening efficacy. We recommend that screening programs collect detailed longitudinal, individual-level data, not only for the screening tests themselves but additionally for diagnostic follow-up and surveillance exams, to allow for maximum flexibility in reporting adherence patterns using the measure of choice.

Differential effects of colorectal cancer screening across sociodemographic groups in Denmark: a register-based study

INTRODUCTION

Colorectal cancer (CRC) does not affect different sociodemographic groups uniformly. CRC screening programmes could seek to reduce this inequality; however, the screening programmes themselves might be subject to differential participation across sociodemographic groups. This study investigates the sociodemographic inequality at all steps in Denmark's nationwide CRC screening programme: screening participation, faecal immunochemical test (FIT) results, colonoscopy compliance, CRC diagnosis, and cancer stage.

MATERIAL AND METHODS

This cohort study includes all first-time invitees from the beginning of the Danish population-based CRC screening programme from 1 March 2014 to 31 December 2017.

RESULTS

Sixty-four percent of the invitees participated in the screening programme, and of those 7% were FIT-positive. After being invited to further diagnostic procedures, 90% responded to the invitation, and among those 5% were CRC-positive. Among those diagnosed with CRC, 9% were stage IV. Through multivariable analyses, we identified sociodemographic inequalities in all steps of the screening programme from returning a stool sample to being diagnosed with CRC. Specifically, we identified inequalities across sex, age, migration status, relationship status, the screening status of one's partner, education, income, and use of health services. Women were more likely to participate compared to men (RR = 1.13; 95% CI: 1.12-1.13), but had a lower risk of a positive FIT result (RR = 0.67; 95% CI: 0.66-0.68) and of a CRC diagnosis (RR = 0.88; 95% CI: 0.82-0.93) compared to men. The likelihood of participating as well as the risk of positive FIT results and CRC diagnosis increased with age.

CONCLUSION

All steps of the screening programme were subject to sociodemographic inequalities. Interventions are needed to target groups identified as having lower uptake as well as high-risk of being FIT- and/or CRC-positive. These groups include males, individuals aged 60+ years and individuals who do not visit their GP regularly.

Evaluating Screening Participation, Follow-up, and Outcomes for Breast, Cervical, and Colorectal Cancer in the PROSPR Consortium

BACKGROUND

Cancer screening is a complex process encompassing risk assessment, the initial screening examination, diagnostic evaluation, and treatment of cancer precursors or early cancers. Metrics that enable comparisons across different screening targets are needed. We present population-based screening metrics for breast, cervical, and colorectal cancers for nine sites participating in the Population-based Research Optimizing Screening through Personalized Regimens consortium.

METHODS

We describe how selected metrics map to a trans-organ conceptual model of the screening process. For each cancer type, we calculated calendar year 2013 metrics for the screen-eligible target population (breast: ages 40-74 years; cervical: ages 21-64 years; colorectal: ages 50-75 years). Metrics for screening participation, timely diagnostic evaluation, and diagnosed cancers in the screened and total populations are presented for the total eligible population and stratified by age group and cancer type.

RESULTS

The overall screening-eligible populations in 2013 were 305 568 participants for breast, 3 160 128 for cervical, and 2 363 922 for colorectal cancer screening. Being up-to-date for testing was common for all three cancer types: breast (63.5%), cervical (84.6%), and colorectal (77.5%). The percentage of abnormal screens ranged from 10.7% for breast, 4.4% for cervical, and 4.5% for colorectal cancer screening. Abnormal breast screens were followed up diagnostically in almost all (96.8%) cases, and cervical and colorectal were similar (76.2% and 76.3%, respectively). Cancer rates per 1000 screens were 5.66, 0.17, and 1.46 for breast, cervical, and colorectal cancer, respectively.

CONCLUSIONS

Comprehensive assessment of metrics by the Population-based Research Optimizing Screening through Personalized Regimens consortium enabled systematic identification of screening process steps in need of improvement. We encourage widespread use of common metrics to allow interventions to be tested across cancer types and health-care settings.

Smoking pattern and risk of lung cancer among women participating in cancer screening programmes

OBJECTIVES

The aim of this study was to describe the smoking prevalence, the smoking pattern, and the risk of lung cancer among women who participated in a cancer screening (breast, cervical and colorectal) in Spain.

METHODS

We used data from the Spanish National Health Survey of 2011-12, a cross-sectional study of the adult Spanish population from women in the age of participation in the population cancer screening. We used two definitions of the high risk of lung cancer according to the National Lung Screening Trial (NLST) criteria and the NELSON criteria.

RESULTS

Participation in screening was 76.6% in breast cancer, 6.6% in colorectal cancer, and 70.3% in cervical cancer. The percentage of current smokers was 17.1 of women who participated breast cancer, 15.4 of women who participated colorectal cancer, and 26.1 of women who participated cervical cancer. According to NLST criteria, the percentage of current smokers women who had a high risk of lung cancer was 23.1 for breast cancer, 23.5 for colorectal cancer and 4.5 for cervical cancer. These figures were higher with the NELSON criteria.

CONCLUSION

At least 250 000 women in Spain have a high risk of lung cancer and are participating in a cancer screening programme. These programmes might be an opportunity for implementing specific interventions aiming to reduce this risk.

Advancing Cancer Control in San Francisco: Cancer Screening in Under-Represented Populations

INTRODUCTION

Cancer risk and screening data are limited in their ability to inform local interventions to reduce the burden of cancer in vulnerable populations. The San Francisco Health Information National Trends Survey was developed and administered to assess the use of cancer-related information among under-represented populations in San Francisco to provide baseline data for the San Francisco Cancer Initiative.

METHODS

The survey instrument was developed through consultation with research and community partners and translated into 4 languages. Participants were recruited between May and September 2017 through community-based snowball sampling with quotas to ensure adequate numbers of under-represented populations. Chi-square tests and multivariate logistic regression were used between 2018 and 2019 to assess differences in screening rates across groups and factors associated with cancer screening.

RESULTS

One thousand twenty-seven participants were recruited. Asians had lower rates of lifetime mammogram (p=0.02), Pap test (p<0.01), and prostate-specific antigen test (p=0.04) compared with non-Asians. Hispanics had higher rates of lifetime mammogram (p=0.02), lifetime Pap test (p=0.01), recent Pap test (p=0.03), and lifetime prostate-specific antigen test (p=0.04) compared with non-Hispanics. Being a female at birth was the only factor that was independently associated with cancer screening participation (AOR=3.17, 95% CI=1.40, 7.19).

CONCLUSIONS

Screening adherence varied by race, ethnicity, and screening type. A collaborative, community-based approach led to a large, diverse sample and may serve as a model for recruiting diverse populations to add knowledge about cancer prevention preferences and behaviors. Results suggest targeted outreach efforts are needed to address disparate cancer screening behaviors within this diverse population.

Colorectal cancer risk factors in asymptomatic Chilean population: a survey of international collaboration between Japan and Chile

In Chile, the mortality from colorectal cancer has been on the rise. A national screening program based on a fecal immunochemical test was started in 2012 as an international collaboration with Japan. This case-control study was designed to identify the risk factors for colorectal cancer, with a goal of increasing the participation rate for colorectal cancer screening. In accordance with the Strengthening the Reporting of Observational Studies in Epidemiology guidelines, we conducted a case-control study from 2012 to 2017; 23 845 asymptomatic participants were enrolled in the study. Participants who were fecal immunochemical test-positive or had a family history of colorectal cancer underwent a colonoscopy. We analyzed the odds ratio of the risk factors for colorectal cancer, including sex, age, family history, BMI, hypertension, diabetes, regular use of nonsteroidal anti-inflammatory drugs, alcohol consumption, smoking, physical activity, and daily intake of certain food items. For the screening program, 202 cases of colorectal cancer were detected, and 195 of them were evaluated pathologically after resection. Of these, 173 cases (88.7%) had colorectal cancer stage 0/1, 151 (77.4%) of which were treated with endoscopic resection. In the multivariate analysis, male sex, family history of colorectal cancer, and low intake of cereals or fibers were closely related to a high colorectal cancer incidence. Moreover, participants in their 60s and 70s had a higher incidence of colorectal cancer than those in their 50s. These results suggest that intensive screening of the high-risk population can help in improving the detection of colorectal cancer, whereas higher consumption of cereals or fibers can be effective in preventing its onset.

Performance of colorectal cancer screening in the European Union Member States: data from the second European screening report

OBJECTIVE

To present comparative data about the performance of colorectal cancer (CRC) screening programmes in the European Union Member States (EU MSs).

DESIGN

Cross-sectional study. We analysed key performance indicators-participation rate, positivity rate (PR), detection rate (DR) and positive predictive value for adenomas and CRC-based on the aggregated quantitative data collected for the second EU screening report. We derived crude and pooled (through a random effects model) estimates to describe and compare trends across different MSs/regions and screening protocols.

RESULTS

Participation rate was higher in countries adopting faecal immunochemical test (FIT) (range: 22.8%-71.3%) than in those using guaiac faecal occult blood test (gFOBT) (range 4.5%-66.6%), and it showed a positive correlation (ρ=0.842, p<0.001) with participation in breast cancer screening in the same areas. Screening performance showed a large variability. Compliance with referral for colonoscopy (total colonoscopy (TC)) assessment ranged between 64% and 92%; TC completion rate ranged between 92% and 99%. PR and DR of advanced adenomas and CRC were higher in FIT, as compared with gFOBT programmes, and independent of the protocol among men, older subjects and those performing their first screening.

CONCLUSIONS

The variability in the results of quality indicators across population-based screening programmes highlights the importance of continuous monitoring, as well as the need to promote quality improvement efforts, as recommended in the EU guidelines. The implementation of monitoring systems, ensuring availability of data for the entire process, together with initiatives aimed to enhance reproducibility of histology and quality of endoscopy, represent a priority in screening programmes management.

Longitudinal Adherence to Immunochemical Fecal Occult Blood Testing vs Guaiac-based FOBT in an Organized Colorectal Cancer Screening Program

Longitudinal adherence is a critical component of the efficacy of stool-based screening programs because they should be repeated every 1-2 years. Few data have been published on the uptake in multiple rounds of fecal occult blood test-based (FOBT) colorectal cancer (CRC) screening. We calculated two measures of longitudinal adherence to biennial FOBT (guaiac fecal occult blood test:gFOBT or fecal immunochemical test:FIT) to better understand its impact on the programmatic effectiveness of a population-based CRC screening program (2000-2017). Ongoing population-based CRC program of men and women aged 50-69 years. Variables: Age at first CRC screening invitation, sex, number of screening invitations, number of screens, deprivation score, and uptake rate. Logistic regression models were used to assess the independent effect of sex, age at first invitation, deprivation, and the type of screening test offered on adherence. The uptake rate for guaiac fecal occult blood test (gFOBT) was 23.9%, and for the fecal immunochemical test (FIT), it was 37.4%. The overall rate of consistently screened invitees after seven rounds of screening was 14.2%, being 20.6% for those individuals who used FIT and 14.3% for those who used gFOBT. Factors associated with continued participation (consistent vs. inconsistent screenees) showed that the longitudinal adherence was associated with age, screening test used, and number of invitations. Continued participation was lower in individuals who were screened using FIT than among those screened using gFOBT [OR, 0.68; 95% confidence interval (CI), 0.57-0.81]. The overall rate of consistently screened invitees for colorectal cancer screening was higher with FIT than gFOBT. Studying the rate of individuals being current for screening may help to anticipate potential benefits before the long-term outcome data are available.

Testing behavioral interventions to optimize participation in a population-based colorectal cancer screening program in Catalonia, Spain

The aim of the study was to measure the effect of three cost-neutral behavioral interventions on participation compared to the standard invitation letter in a population-based colorectal cancer screening program in 2014. For that purpose, a four-arm randomized field trial was conducted among 5077 individuals aged 50 to 69 years. Over an 8-week period, each week was randomly allocated to the intervention or the control conditions. Individuals assigned to the intervention conditions additionally received a prompt to write down the date to pick up the screening test in a pharmacy. Two of the three intervention groups also included an additional paragraph in the invitation letter on either: 1) the high proportion of individuals participating regularly (social norms condition) or 2) the importance of regular participation (benefit condition). We measured screening participation before and after receiving a reminder letter six weeks after the screening invitation. An overall 8.0 percentage point increase in CRC screening was achieved as a direct result of receiving a reminder letter; however none of the intervention strategies influenced participation. The only significant difference was found for newly invited individuals. There, participation rates decreased from 34.9% to 24.2% when the invitation mailing mentioned the importance of regular participation (OR: 0.60; 95% CI: 0.38-0.95). While none of the intervention strategies improved participation rates we found that praising the benefit of regular screening may discourage individuals who have never been invited before as the continuous behavior may be perceived as a large request. Nevertheless, the reminder letter boosted participation rates independently of the intervention assigned.

General practitioners' perceptions of population based bowel screening and their influence on practice: a qualitative study

Background

Although largely preventable, Australia has one of the highest rates of bowel cancer in the world. General Practitioners (GPs) have an important role to play in prevention and early detection of bowel cancer, however in Australia this is yet to be optimised and participation remains low. This study sought to understand how GPs’ perceptions of bowel screening influence their attitudes to, and promotion of the faecal occult blood test (FOBT), to identify opportunities to enhance their role.

Methods

Interviews were conducted with 31 GPs from metropolitan and regional New South Wales (NSW), Australia. Discussions canvassed GPs’ perceptions of their role in bowel screening and the national screening program; perceptions of screening tests; practices regarding discussing screening with patients; and views on opportunities to enhance their role. Transcripts were coded using Nvivo and thematically analysed.

Results

The study revealed GPs’ perceptions of screening did not always align with broader public health definitions of ‘population screening’. While many GPs reportedly understood the purpose of population screening, notions of the role of asymptomatic screening for bowel cancer prevention were more limited. Descriptions of screening centred on two major uses: the use of a screening ‘process’ to identify individual patients at higher risk; and the use of screening ‘tools’, including the FOBT, to aid diagnosis. While the FOBT was perceived as useful for identifying patients requiring follow up, GPs expressed concerns about its reliability. Colonoscopy by comparison, was considered by many as the gold standard for both screening and diagnosis. This perception reflects a conceptualisation of the screening process and associated tools as an individualised method for risk assessment and diagnosis, rather than a public health strategy for prevention of bowel cancer.

Conclusion

The results show that GPs’ perceptions of screening do not always align with broader public health definitions of ‘population screening’. Furthermore, the way GPs understood screening was shown to impact their clinical practice, influencing their preferences for, and use of ‘screening’ tools such as FOBT. The findings suggest emphasising the preventative opportunity of FOBT screening would be beneficial, as would formally engaging GPs in the promotion of bowel screening.

Defining and measuring adherence to cancer screening

BACKGROUND

The importance of cancer screening is well-recognized, yet there is great variation in how adherence is defined and measured. This manuscript identifies measures of screening adherence and discusses how to estimate them.

DISCUSSION

We begin by describing why screening adherence is of interest: to anticipate long-term outcomes, to understand differences in outcomes across settings, and to identify areas for improvement. We outline questions of interest related to adherence, including questions about uptake, currency or being up-to-date, and longitudinal adherence, and then identify which measures are most appropriate for each question. Our discussion of how to select measures focuses on study inclusion criteria and outcome definitions. Finally, we describe how to estimate different measures using data from two common data sources: survey studies and surveillance studies. Estimation requires consideration of data sources, inclusion criteria, and outcome definitions. Censoring often will be present and must be accounted for.

CONCLUSION

We conclude that consistent definitions and estimation of adherence to cancer screening guidelines will facilitate comparison across studies, tests, and settings, and help to elucidate areas for future research and intervention.

Optimising colorectal cancer screening acceptance: a review

The study aims to review available evidence concerning effective interventions to increase colorectal cancer (CRC) screening acceptance. We performed a literature search of randomised trials designed to increase individuals' use of CRC screening on PubMed, Embase, Cochrane Database of Systematic Reviews and Database of Abstracts of Reviews of Effects. Small (≤ 100 subjects per arm) studies and those reporting results of interventions implemented before publication of the large faecal occult blood test trials were excluded. Interventions were categorised following the Continuum of Cancer Care and the PRECEDE-PROCEED models and studies were grouped by screening model (opportunistic vs organised). Multifactor interventions targeting multiple levels of care and considering factors outside the individual clinician control, represent the most effective strategy to enhance CRC screening acceptance. Removing financial barriers, implementing methods allowing a systematic contact of the whole target population, using personal invitation letters, preferably signed by the reference care provider, and reminders mailed to all non-attendees are highly effective in enhancing CRC screening acceptance. Physician reminders may support the diffusion of screening, but they can be effective only for individuals who have access to and make use of healthcare services. Educational interventions for patients and providers are effective, but the implementation of organisational measures may be necessary to favour their impact. Available evidence indicates that organised programmes allow to achieve an extensive coverage and to enhance equity of access, while maximising the health impact of screening. They provide at the same time an infrastructure allowing to achieve a more favourable cost-effectiveness profile of potentially effective strategies, which would not be sustainable in opportunistic settings.

Participation rates for organized colorectal cancer screening programmes: an international comparison

OBJECTIVE

Participation, an indicator of screening programme acceptance and effectiveness, varies widely in clinical trials and population-based colorectal cancer (CRC) screening programmes. We aimed to assess whether CRC screening participation rates can be compared across organized guaiac fecal occult blood test (G-FOBT)/fecal immunochemical test (FIT)-based programmes, and what factors influence these rates.

METHODS

Programme representatives from countries participating in the International Cancer Screening Network were surveyed to describe their G-FOBT/FIT-based CRC screening programmes, how screening participation is defined and measured, and to provide participation data for their most recent completed screening round.

RESULTS

Information was obtained from 15 programmes in 12 countries. Programmes varied in size, reach, maturity, target age groups, exclusions, type of test kit, method of providing test kits and use, and frequency of reminders. Coverage by invitation ranged from 30-100%, coverage by the screening programme from 7-67.7%, overall uptake/participation rate from 7-67.7%, and first invitation participation from 7-64.3%. Participation rates generally increased with age and were higher among women than men and for subsequent compared with first invitation participation.

CONCLUSION

Comparisons among CRC screening programmes should be made cautiously, given differences in organization, target populations, and interpretation of indicators. More meaningful comparisons are possible if rates are calculated across a uniform age range, by gender, and separately for people invited for the first time vs. previously.

Participation in four rounds of a French colorectal cancer screening programme with guaiac faecal occult blood test: a population-based open cohort study

Objectives

Four randomized controlled trials have demonstrated the efficacy of screening using a guaiac faecal occult blood test (gFOBT) on colorectal cancer (CRC) mortality. Whether their results are transposable to the real world is unknown. This study aimed to assess the determinants of participation in the first four rounds of the CRC screening programme using a gFOBT implemented since 2003 in the Haut-Rhin (Alsace) part of the French national programme.

Methods

We performed a population-based open cohort study of all residents aged 50–74, around 200,000 people. They were invited by mail to participate every other year. The gFOBT kits (Hemoccult II) were first provided by general practitioners, and then directly mailed to persons who failed to comply.

Results

The uptake decreased significantly across all rounds, from 54.3% to 47.1% (p < 0.0001), mainly in people younger than 60. The proportion of people screened by general practitioners increased significantly from 77.0% in the first round to 84.2% in the fourth (p < 0.01). Overall, 61.3% of the invited population participated at least once, and 14.3% had completed all the four tests. The colonoscopy uptake was around 91%, among the highest ever reported.

Conclusions

Despite the involvement of general practitioners, the uptake and adherence to repeat testing are modest and deteriorate with time, so that the reduction in CRC mortality in reality will be significantly lower than that in the trials. The benefit-risk balance of the French programme is, at present, less favourable than that shown in the trials.

Tests and investigations for colorectal cancer screening

Worldwide, colorectal (CRC) is the third most common form of cancer, after lung and breast cancer, and the fourth most common cause of cancer death, although in developed countries CRC incidence is higher and it accounts for an even higher proportion of cancer deaths. Successful treatment of early-stage CRC confers substantial survival advantage, and there is now overwhelming evidence that screening average-risk individuals for CRC reduces the incidence and disease-specific mortality. In spite of considerable research for new biomarkers for CRC, the detection of blood in faeces remains the most effective screening tool. The best evidence to date for population-based CRC screening comes from randomised-controlled trials that used a guaiac-based faecal occult blood test (gFOBt) as the first-line screening modality, whereby test-positive individuals are referred for follow-up investigations, usually colonoscopy. A major innovation in the last ten years or so has been the development of other more analytically sensitive and specific screening techniques for blood in faeces. The faecal immunochemical test for haemoglobin (FIT) confers substantial benefits over gFOBt in terms of analytical sensitivity, specificity and practicality and FIT are now recommended for CRC screening by the European guidelines for quality assurance in colorectal cancer screening and diagnosis. The challenge internationally is to develop high quality CRC screening programmes for which uptake is high. This is especially important for developing countries witnessing an increase in the incidence of CRC as populations adopt more westernised lifestyles. This review describes the tests available for CRC screening and how they are being used worldwide. The reader will gain an understanding of developments in CRC screening and issues that arise in choosing the most appropriate screening test (or tests) for organised population-based screening internationally and optimising the performance of the chosen test (or tests). Whilst a wide range of literature has been cited, this is not a systematic review. The authors provide FOBT CRC screening for a population of 14.6 million in the south of England and the senior author (SPH) was the lead author of the European guidelines for quality assurance in colorectal cancer screening and diagnosis and leads the World Endoscopy Organization Colorectal Cancer Committee's Expert Working Group on 'FIT for Screening'.