Population-based Colorectal Cancer Screening Research Articles

Testing messages from behavioral economics to improve participation in a population-based colorectal cancer screening program in Cyprus: Results from two randomized controlled trials

Despite the benefits of colorectal cancer (CRC) screening, participation compares poorly to other screening programs. This study assessed the effectiveness of adding different behavioral economic-based messages, to the invitation letter, to increase uptake in the Cypriot CRC screening program. We performed two randomized controlled trials. In the first trial (‘Trial 1’), 3212 individuals, aged 50 to 69 years, were randomly allocated (1:1:1:1:1:1:1) to one of six intervention groups, or the control. The intervention groups received the standard invitation letter received by the control, with the addition of one of six messages based on the following behavioral economics principles: (1) social responsibility, (2) anticipated regret, (3) financial opportunity costs (of non-attendance), (4) benefit (of early detection), (5) scarcity effect (limited duration of the offer) and (6) social norms. The second trial (‘Trial 2’) tested the most efficacious message (social responsibility) against the control in a larger sample (N = 3074). In both trials, the primary outcome was uptake eight weeks after the screening invitation. In trial 1, overall uptake was 20.6%. There were no significant differences between the control and the intervention conditions for the overall sample or men (all p’s > 0.05).Highlighting the social consequences of cancer did, however, increase uptake rates among women (25.6% vs. 17.1%, aOR 1.67; 95% CI 1.05–2.66, p = 0.031). We, therefore, tested this message in Trial 2. Uptake was similar to trial 1 with 20.7% (intervention: 20.8% vs control: 20.6%) and there was no impact on overall or uptake of men and women separately (all p’s > 0.05).

Clinical Validation of a Multitarget Fecal Immunochemical Test for Colorectal Cancer Screening : A Diagnostic Test Accuracy Study.

The fecal immunochemical test (FIT) is used in colorectal cancer (CRC) screening, yet it leaves room for improvement. To develop a multitarget FIT (mtFIT) with better diagnostic performance than FIT. Diagnostic test accuracy study. Colonoscopy-controlled series. Persons (n = 1284) from a screening (n = 1038) and referral (n = 246) population were classified by their most advanced lesion (CRC [n = 47], advanced adenoma [n = 135], advanced serrated polyp [n = 30], nonadvanced adenoma [n = 250], and nonadvanced serrated polyp [n = 53]), along with control participants (n = 769). Antibody-based assays were developed and applied to leftover FIT material. Classification and regression tree (CART) analysis was applied to biomarker concentrations to identify the optimal combination for detecting advanced neoplasia. Performance of this combination, the mtFIT, was cross-validated using a leave-one-out approach and compared with FIT at equal specificity. The CART analysis showed a combination of hemoglobin, calprotectin, and serpin family F member 2-the mtFIT-to have a cross-validated sensitivity for advanced neoplasia of 42.9% (95% CI, 36.2% to 49.9%) versus 37.3% (CI, 30.7% to 44.2%) for FIT (P = 0.025), with equal specificity of 96.6%. In particular, cross-validated sensitivity for advanced adenomas increased from 28.1% (CI, 20.8% to 36.5%) to 37.8% (CI, 29.6% to 46.5%) (P = 0.006). On the basis of these results, early health technology assessment indicated that mtFIT-based screening could be cost-effective compared with FIT. Study population is enriched with persons from a referral population. Compared with FIT, the mtFIT showed better diagnostic accuracy in detecting advanced neoplasia because of an increased detection of advanced adenomas. Moreover, early health technology assessment indicated that these results provide a sound basis to pursue further development of mtFIT as a future test for population-based CRC screening. A prospective screening trial is in preparation. Stand Up to Cancer/Dutch Cancer Society, Dutch Digestive Foundation, and HealthHolland.

Modelling the impacts of COVID-19 pandemic on the quality of population-based colorectal cancer screening

COVID-19 pandemic has severely affected regular public health interventions including population-based cancer screening. Impacts of such screening delays on the changes in structure and screening process and the resultant long-term outcomes are unknown. It is therefore necessary to develop a systematic framework to assess theses impacts related to these components of quality. Using population-based cancer screening with fecal immunochemical test (FIT) as an illustration, the main analysis was to assess how various scenarios of screening delays were associated with the capacity for primary screening and full time equivalent (FTE) for colonoscopy and impact long-term outcomes based on a Markov decision tree model on population level. The second analysis was to quantify how the extent of COVID-19 epidemic measured by social distancing index affected capacity and FTE that were translated to delays with an exponential relationship. COVID-19 epidemic led to 25%, 29%, 34%, and 39% statistically significantly incremental risks of late cancer for the delays of 0.5-year, 1-year,1.5-year, and 2-year, respectively compared with regular biennial FIT screening. The corresponding statistically findings of four delayed schedules for death from colorectal cancer (CRC) were 26%, 28%, 29%, and 30%, respectively. The higher social distancing index led to a lower capacity of uptake screening and a larger reduction of FTE, resulting in longer screening delay and longer waiting time, which further impacted long-term outcomes as above. In summary, a systematic modelling approach was developed for demonstrating the strong impact of screening delays caused by COVID-19 epidemic on long-term outcomes illustrated with a Taiwan population-based FIT screening of CRC.

Gender-specific cut-off levels in colorectal cancer screening with fecal immunochemical test: A population-based study of colonoscopy findings and costs.

In the population-based Swedish regional colorectal cancer (CRC) screening program of Stockholm-Gotland using the fecal immunochemical test (FIT), gender-specific cut-off levels of fecal hemoglobin are applied, since previous studies have indicated a lower sensitivity of FIT for CRC in women. The aim was to evaluate the diagnostic yield and the screening costs overall and per detected CRC of this strategy. All individuals aged 60-69 invited to screening in 2015-2017 were included. Cut-off level for positive FIT was 40 µg/g in women and 80 µg/g in men. Those with a positive FIT were referred to colonoscopy. The yield of CRC and screening cost for the study period were assessed and compared to cut-off levels of 80 µg/g in both genders. Approximately 230,000 individuals were invited. Overall participation rates were 72% in women and 65% in men (p < 0.05). FIT was positive in 4256 individuals (2.7% in both genders). In 3758 colonoscopies, 258 (6.9%) CRCs were detected. The positive predictive value for CRC was significantly higher in men (8.3% vs. 5.8%). In 120 women with CRC, 28 (23%) had FIT < 80 µg/g. Negative colonoscopies were more common in women (24% vs. 17%, p < 0.05). Total costs for the study period were 52,000,000SEK (≈5,200,000€), i.e. 16% higher compared to using cut-off levels of 80 µg/g in both genders, and corresponding to a 3% increment in cost per detected CRC. The high rate of CRC detected in women in the lowest FIT category outweighs the minor reduction in screening costs if the same cut-off level was used as for men.

The impact of colorectal cancer screening on incidence and stage IV disease in the Netherlands.

3531 Background: Population-based screening for colorectal cancer (CRC) aims to decrease incidence and mortality due to precancerous polyp removal, early detection and early treatment of CRC. In the Netherlands, phased introduction of a biennial fecal immunochemical hemoglobin test started in 2014 for individuals aged 55-75. This evaluation of the national data focuses on the initial effect of CRC screening on incidence and stage distribution and the impact on stage IV disease. Methods: All CRC patients diagnosed in the Netherlands between 2009 and 2018 were selected from the Netherlands Cancer Registry (NCR). Patients were linked to the Dutch national pathology registry (PALGA) to identify screen-detected tumors. Results: The NCR identified 137,717 CRC patients between 2009 and 2018. The incidence within screening age (55-75 yr) of all CRC stages showed an initial peak after introduction of screening in 2014, followed by a continuous decrease for all stages. CRC incidence outside the screening age did not show these explicit changes between 2009 and 2018. In 2018, the incidence of stage IV CRC within screening age was lower than the level at the start of the screening program. Stage distribution within screening age shifted towards earlier stages in the screening period (2014-2018) compared to the period before screening (2009-2012) (stage I: 31% vs. 18%, stage II: 22% vs. 26%, stage III: 29% vs. 31%, Stage IV: 18% vs. 25%, respectively). In the period 2014-2018 and within screening age, the ratio of screen-detected and symptom-detected tumors was highest in stage I (47%:53%) and lowest in stage IV (9%:91%). Screen-detected compared to symptom-detected stage IV patients diagnosed in the period 2014-2018 and within screening age had more frequently single organ metastases (74.5% vs 57.4%, p &lt; 0.001), higher resection rate of the primary tumor (57.5% vs. 41.3%; p &lt; 0.001) and higher local treatment rate of metastases (40.0% vs. 23.4% p &lt; 0.001). The median overall survival of screen-detected stage IV patients was significantly longer than that of symptom-detected stage IV patients (31.0 months (95% CI: 27.7 – 34.3) vs. 15.0 months (95% CI: 14.5 – 15.5), p &lt; 0.001). Conclusions: The initial results of the introduction of CRC screening in the Netherlands showed a favorable trend on CRC incidence and stage distribution. Screen-detected patients with stage IV disease had less extensive disease, resulting in better treatment options and improved survival.

Aspirin, ibuprofen, and reduced risk of advanced colorectal adenoma incidence and recurrence and colorectal cancer in the PLCO Cancer Screening Trial.

Studying the differential impact of aspirin and other nonsteroidal anti-inflammatory drugs across the stages of colorectal neoplasia from early adenoma to cancer is critical for understanding the benefits of these widely used drugs. With 13 years of follow-up, the authors prospectively evaluated the association between aspirin and ibuprofen use and incident distal adenoma (1221 cases), recurrent adenoma (862 cases), and incident colorectal cancer (CRC; 2826 cases) among men and women in the population-based Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. With multivariable-adjusted models, odds ratio (ORs) and 95% confidence intervals (CIs) for adenoma incidence and recurrence and hazard ratios (HRs) and 95% CIs for incident CRC were determined. The authors observed a significantly reduced risk of incident adenoma with ibuprofen use (≥30 vs <4 pills per month: OR, 0.76 [95% CI, 0.60-0.95]; Ptrend = .04), particularly advanced adenoma (OR, 0.48 [95% CI, 0.28-0.83]; Ptrend = .005). Among those with a previous adenoma detected through screening, aspirin use was associated with a decreased risk of advanced recurrent adenoma (≥30 vs <4 pills per month: OR, 0.56 [95% CI, 0.36-0.87]; Ptrend = 0.006). Both aspirin (HR, 0.88 [95% CI, 0.81-0.96]; Ptrend <.0001) and ibuprofen use (HR, 0.81 [95% CI, 0.70-0.93); Ptrend = 0.003) ≥30 versus <4 pills per month were significantly associated with reduced CRC risk. In this large prospective study with long-term follow-up, a beneficial role for not only aspirin, but also ibuprofen, in preventing advanced adenoma and curbing progression to recurrence and cancer among older adults was observed.

Colorectal cancer screening using a stool DNA-based SDC2 methylation test: a multicenter, prospective trial

BackgroundPrevention and early detection of colorectal cancer (CRC) is a global priority, with many countries conducting population-based CRC screening programs. Although colonoscopy is the most accurate diagnostic method for early CRC detection, adherence remains low because of its invasiveness and the need for extensive bowel preparation. Non-invasive fecal occult blood tests or fecal immunochemical tests are available; however, their sensitivity is relatively low. Syndecan-2 (SDC2) is a stool-based DNA methylation marker used for early detection of CRC. Using the EarlyTect™-Colon Cancer test, the sensitivity and specificity of SDC2 methylation in stool DNA for detecting CRC were previously demonstrated to be greater than 90%. Therefore, a larger trial to validate its use for CRC screening in asymptomatic populations is now required.MethodsAll participants will collect their stool (at least 20 g) before undergoing screening colonoscopy. The samples will be sent to a central laboratory for analysis. Stool DNA will be isolated using a GT Stool DNA Extraction kit, according to the manufacturer’s protocol. Before performing the methylation test, stool DNA (2 µg per reaction) will be treated with bisulfite, according to manufacturer’s instructions. SDC2 and COL2A1 control reactions will be performed in a single tube. The SDC2 methylation test will be performed using an AB 7500 Fast Real-time PCR system. CT values will be calculated using the 7500 software accompanying the instrument. Results from the EarlyTect™-Colon Cancer test will be compared against those obtained from colonoscopy and any corresponding diagnostic histopathology from clinically significant biopsied or subsequently excised lesions. Based on these results, participants will be divided into three groups: CRC, polyp, and negative. The following clinical data will be recorded for the participants: sex, age, colonoscopy results, and clinical stage (for CRC cases).DiscussionThis trial investigates the clinical performance of a device that allows quantitative detection of a single DNA marker, SDC2 methylation, in human stool DNA in asymptomatic populations. The results of this trial are expected to be beneficial for CRC screening and may help make colonoscopy a selective procedure used only in populations with a high risk of CRC.Trial registration: This trial (NCT04304131) was registered at ClinicalTrials.gov on March 11, 2020 and is available at https://clinicaltrials.gov/ct2/show/NCT04304131?cond=NCT04304131&draw=2&rank=1.

Determinants of Population-Based Cancer Screening Performance at Primary Healthcare Institutions in China.

Background: For a decade, most population-based cancer screenings in China are performed by primary healthcare institutions. To assess the determinants of performance of primary healthcare institutions in population-based breast, cervical, and colorectal cancer screening in China. Methods: A total of 262 primary healthcare institutions in Tianjin participated in a survey on cancer screening. The survey consisted of questions on screening tests, the number of staff members and training, the introduction of the screening programs to residents, the invitation of residents, and the number of performed screenings per year. Logistic regression models were used to analyze the determinants of performance of an institution to fulfil the target number of screenings. Results: In 58% and 61% of the institutions between three and nine staff members were dedicated to breast and cervical cancer screening, respectively, whereas in 71% of the institutions ≥10 staff members were dedicated to colorectal cancer screening. On average 60% of institutions fulfilled the target number of breast and cervical cancer screenings, whereas 93% fulfilled the target number for colorectal cancer screening. The determinants of performance were rural districts for breast (OR = 5.16 (95%CI: 2.51–10.63)) and cervical (OR = 4.17 (95%CI: 2.14–8.11)) cancer screenings, and ≥3 staff members dedicated to cervical cancer screening (OR = 2.34 (95%CI: 1.09–5.01)). Conclusions: Primary healthcare institutions in China perform better in colorectal than in breast and cervical cancer screening, and institutions in rural districts perform better than institutions in urban districts. Increasing the number of staff members on breast and cervical cancer screening could improve the performance of population-based cancer screening.

Colorectal cancer risk following polypectomy in a multicentre, retrospective, cohort study: an evaluation of the 2020 UK post-polypectomy surveillance guidelines

ObjectiveColonoscopy surveillance aims to reduce colorectal cancer (CRC) incidence after polypectomy. The 2020 UK guidelines recommend surveillance at 3 years for ‘high-risk’ patients with ≥2 premalignant polyps (PMPs), of which...

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.

Role of community pharmacies in a population-based colorectal cancer screening program

In Catalonia (Spain), population-based colorectal cancer (CRC) screening offers biennial fecal occult blood testing to men and women aged 50–69 years old. The program is organized in screening hubs, most of which use a pharmacy-based model to distribute and collect fecal immunochemical test (FIT) kits The comprehensive evaluation of CRC screening programs, which include the role and implications of pharmacy involvement, is essential to ensure program quality and identify areas for further improvement. The present study aimed to assess the adherence of community pharmacies to the CRC screening program and to analyze data on FIT kit distribution and collection in the Metropolitan area of Barcelona (Catalonia, Spain). Time to FIT completion was assessed by Kaplan-Meier estimation, and with the log-rank test. A Cox regression model was used to adjust for other variables associated with the completion of FIT such as sex, age, deprivation score index and previous screening behavior. Overall, 82.4% of pharmacies adhered with CRC screening program. Out of 82,902 FIT kits distributed to screening invitees 77,524 completed FIT kits were returned to pharmacies (93.5%) with a participation of 39.8% among the 193,766 invitees. From those who completed a FIT, the median time to return the kit was 3 days. FIT completion time was significantly lower among women, older age, high deprivation score index and previous CRC screening (p < 0.005). Our findings highlight the large involvement of community pharmacists with CRC screening program as well as a high quality in the process of FIT distribution and collection.

Accuracy of Finnish Cancer Registry colorectal cancer data: a comparison between registry data and clinical records

Background The population-based Finnish Cancer Registry (FCR) is an important resource for research and healthcare politics in Finland. The aim of this study was to validate the accuracy of the colorectal cancer (CRC) data within the FCR. Material and methods FCR data are based on independent cancer report forms (CRFs) from both clinicians and pathologists. Data from patients diagnosed with CRC during a randomized, population-based CRC screening program between 2004 and 2012 were extracted from the FCR and compared to data extracted from the original clinical patient records of these individuals by two gastrointestinal surgeons. The study focused on tumour characteristics and primary treatment. Accuracy was measured by calculating Cohen’s kappa coefficient (κ), which considers the possibility of agreement by chance. Results Altogether, 1475 patients were studied. κ was 0.74 for stage, 0.87 for tumour location (right/left), 0.78 for a more detailed location, 0.72 for tumour histology, 0.46 for surgical removal of the primary tumour, and 0.43 for chemotherapy. Among those who underwent surgery, the radicality of surgical treatment had a κ of 0.24. In total, 173 (12%) patients were lacking a CRF from a clinician. Conclusion The FCR data had good accuracy regarding tumour characteristics, but poor accuracy in treatment information. The main reason for this suboptimal accuracy was missing CRFs from treating clinicians. Awareness of these findings is crucial when research and decision making is based on FCR data. Measures have since been taken to improve the completeness of FCR recording.

Divergent detection rates of fecal immunochemical test and questionnaire-based risk assessment for detecting proximal and distal advanced colorectal adenomas

Divergent detection rates of fecal immunochemical test and questionnaire-based risk assessment for detecting proximal and distal advanced colorectal adenomas

Estimating the preferences and willingness-to-pay for colorectal cancer screening: an opportunity to incorporate the perspective of population at risk into policy development in Thailand

Aims Colorectal cancer (CRC) is one of the public health burdens that can be lowered by early detection. This study aims to examine the preferences and willingness-to-pay of a population at risk for CRC screening in Thailand. Understanding the preferences for these individuals at risk would help Thailand, as an example of LMICs, to design effective population-based CRC screening programs. Materials and methods A discrete choice experiment (DCE) was conducted among screening-naïve adults aged 50–75 years, who were at risk of CRC, in the out-patient department of a tertiary care hospital in Thailand. A DCE questionnaire was developed from six CRC screening attributes. Each questionnaire was composed of six choice sets and each contained two alternatives described by the different levels of attributes and an opt-out alternative. Participants were asked to choose one alternative from each choice set. A multinomial logit model was developed to determine the relative preference of each attribute. The willingness-to-pays for all attributes and screening modalities and the estimated preferred choices of the annual fecal immunochemical test (FIT), 10-yearly colonoscopy, 5-yearly double-contrast barium enema (DCBE), 5-yearly computed tomographic colonography (CTC), 5-yearly flexible sigmoidoscopy (FS), and no screening was calculated and compared. Results Four hundred participants were included. All attributes, except pain and less bowel preparation, were statistically associated with the participants’ preference (p < .05). They preferred screenings with a high-risk reduction of CRC-related mortality, no complication, 5-year interval, and lower cost. The estimated preferred choices of FIT, colonoscopy, DCBE, CTC, and FS were 38.2%, 11.4%, 14.6%, 9.2%, and 11.4%, respectively. The willingness-to-pays for each screening modality was US$251, US$189, US$183, US$154, and US$142 (8,107, 6,105, 5,911, 4,974, and 4,587 THB) per episode, respectively. Conclusions The risk reduction of CRC-related mortality, complication, screening interval, and cost influenced the CRC screening preferences of Thai adults. FIT was the most preferred. Policymakers can develop a successful CRC screening campaign using these findings, incorporating the perspective of the population at risk in policy formulation to accomplish their goals.

Diagnostic performance of quantitative fecal immunochemical test in detection of advanced colorectal neoplasia

Objective: To evaluate the diagnostic performance of quantitative fecal immunochemical testing (FIT) and to provide reference for designing effective colorectal cancer (CRC) screening strategy in China. Methods: Based on an ongoing randomized controlled trial comparing the colorectal cancer screening strategies, this current study involved 3 407 participants aged 50-74 years who had undergone colonoscopies. All the feces samples were collected from the participants prior to receiving the colonoscopy. Fecal hemoglobin (Hb) was tested by FIT following a standardized operation process. Diagnosis-related indicators of FIT were calculated using the colonoscopy results as the gold standard. Results: Among the 3 407 participants, the mean age (SD) as 60.5 (6.3) years and 1 753 (51.5%) were males. The participants involved 28 (0.8%) CRCs, 255 (7.5%) advanced adenomas, 677 (19.9%) nonadvanced adenomas, and 2 447 (71.8%) benign or negative findings. With an overall positivity rate of 2.8% (96/3 407) at the recommended cutoff value of 20 μg Hb/g, the sensitivities of FIT for both CRC and advanced adenoma were 57.1% (95%CI: 37.2%-75.5%) and 11.0% (95%CI: 7.4%-15.5%), respectively, with the corresponding specificity as 98.4% (95%CI: 97.8%-98.8%). At a decreased cut-off value of 5 μg Hb/g, the sensitivities for detecting CRC and advanced adenoma increased to 64.3% (95%CI: 44.1%-81.4%) and 16.5% (95%CI: 12.1%-21.6%), respectively, but the specificity reduced to 95.2% (95%CI: 94.4%-95.9%). The areas under the ROC curve for CRC and advanced adenoma were 0.908 (95%CI: 0.842-0.973) and 0.657 (95%CI: 0.621-0.692), respectively. Of the diagnostic performance, there were no significant differences noticed by different sex and age groups. Conclusions: In our study, the quantitative FIT showed modest sensitivity in detecting CRC but limited sensitivity in detecting advanced adenoma. In population-based CRC screening programs, the quantitative FIT had the advantage of adjusting the positive threshold based on the targeted detection rate and available resource load of colonoscopy.

The Outcome of Unscreened Population in Colorectal Cancer: The Impact of Sex and Other Determinants on Cancer Stage.

BackgroundIn Saudi Arabia, there is no population-based colorectal cancer (CRC) screening, and more than two-thirds of patients are diagnosed with a late stage. We assessed the association between sex and distant metastasis CRC and hypothesize that females, younger age, non-married, and patients with colon cancer would present with metastatic tumors.Patients and MethodsThe retrospective cohort study used data from the Ministry of National Guard Cancer Registry. Logistic regression was used to assess the association between sex and metastatic CRC adjusting for patient covariates. In a sensitivity analysis, the association between sex and late-stage CRC was evaluated.ResultsA total of 1016 CRC patients met the eligibility criteria, with 37.59% of females and 30.26% of males diagnosed with metastatic CRC. After adjusting for marital status, grade, and morphology, females were 20% more likely than males to present with a metastatic tumor 1.20 (95% CI, 1.04–1.38).ConclusionAlthough the entire Saudi population would benefit from CRC screening, women may benefit the most from targeted screening.

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

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. 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. 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. 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.

Colonoscopy-related adverse events and mortality in an Italian organized colorectal cancer screening program.

Post-colonoscopy adverse events are a key quality indicator in population-based colorectal cancer screening programs, and affect safety and costs. This study aimed to assess colonoscopy-related adverse events and mortality in a screening setting. We retrieved data from patients undergoing colonoscopy within a screening program (fecal immunochemical test every 2 years, 50-69-year-olds, or post-polypectomy surveillance) in Italy between 2002 and 2014, to assess the rate of post-colonoscopy adverse events and mortality. Any admission within 30 days of screening colonoscopy was reviewed to capture possible events. Mortality registries were also matched with endoscopy databases to investigate 30-day post-colonoscopy mortality. Association of each outcome with patient-/procedure-related variables was assessed using multivariable analysis. Overall, 117 881 screening colonoscopies (66 584, 56.5 %, with polypectomy) were included. Overall, 497 (0.42 %) post-colonoscopy adverse events occurred: 281 (0.24 %) bleedings (3.69‰/0.68‰, operative/diagnostic procedures) and 65 (0.06 %) perforations (0.75‰/0.29‰, respectively). At multivariable analysis, bleeding was associated with polyp size (≥ 20 mm: odds ratio [OR] 16.29, 95 % confidence interval [CI] 9.38-28.29), proximal location (OR 1.46, 95 %CI 1.14-1.87), and histology severity (high risk adenoma: OR 5.6, 95 %CI 2.43-12.91), while perforation was associated with endoscopic resection (OR 2.91, 95 %CI 1.62-5.22), polyp size (OR 4.34, 95 %CI 1.46-12.92), and proximal location (OR 1.94, 95 %CI 1.12-3.37). Post-colonoscopy mortality occurred in 15 /117 881 cases (1.27/10 000 colonoscopies). In an organized screening program, post-colonoscopy adverse events were rare but not negligible. The most frequent event was post-polypectomy bleeding, especially after resection of large (≥ 20 mm) and proximal lesions.

Determinants of Participation and Detection Rate of Colorectal Cancer From a Population-Based Screening Program in China.

Colorectal cancer (CRC) screening has been widely implemented in Europe and the USA. However, there is little evidence of participation and diagnostic yields in population-based CRC screening in China. The participation rate and detection of colorectal lesions in this program were reported and related factors were explored. The analysis was conducted in the context of the Cancer Screening Program in Urban China, which recruited 282,377 eligible participants aged 40–74 years from eight cities in Henan province from 2013 to 2019. A total of 39,834 participants were evaluated to be high risk for CRC by an established risk score system and were subsequently recommended for colonoscopy. Of 39,834 with high risk for CRC, 7,454 subjects undertook colonoscopy (participation rate of 18.71%). We found that 50–64 years, high level of education, marriage, former smoking, current alcohol drinking, low levels dietary intake of vegetables, high levels dietary intake of processed meat, lack of physical activity, fecal occult blood test positive result, history of colonic polyp, history of colorectitis, and family history of CRC were associated with increased participation of colonoscopy screening. Overall, 17 CRC (0.23%), 95 advanced adenoma (1.27%), 478 non-advanced adenomas dysplasia (6.41%), 248 hyperplastic polyp (3.33%), and 910 other benign lesions (12.21%) were detected. The findings from the study will provide important references for designing effective population-based CRC screening strategies in the future. Given the relatively low participation rate, there was room for improvement in the yield of CRC screening.

P-46 Advanced colorectal adenoma detection based on altered methylation signal in plasma samples

Colorectal cancer is one of the major contributors to cancer-related mortality in the world. Effective population-based screening for colorectal cancer could prevent the development of cancers through the detection of premalignant adenomas, from which at least 80% of sporadic cancers are thought to arise. Existing screening methods include fecal immunochemical testing, which suffers from low accuracy for adenoma detection, and colonoscopy, which is invasive. Measuring the methylation status of the tumor-derived portion of the cell-free DNA in plasma could offer a non-invasive, accurate and high adherence approach for detecting advanced adenomas, helping potentially to decrease colon cancer mortality.