In the past two decades, an extensive rollout of colorectal cancer (CRC) screening programmes has been initiated in European countries with a large heterogeneity of screening offers. Using data from a population-based cross-sectional survey conducted between 2013 and 2016 in all European Union countries, we analysed the utilisation of faecal tests and colonoscopy among people aged 50–74 years and the factors associated with uptake by type of screening offer. We observed the highest utilisation of either test for countries with fully rolled out organised programmes with faecal tests (ranging from 29.7% in Croatia to 66.7% in the UK) and countries offering both faecal tests and colonoscopy (from 22.7% in Greece to 70.9% in Germany). Utilisation was very low for countries with no programme (from 6.3% in Romania to 30.5% in Norway). Younger age (50–54 years), longer time since last consultation with a doctor and a lifestyle score associated with increased CRC risk were significantly associated with lower test use, a pattern observed across all types of screening offers. Our results suggest that more countries should implement organised programmes with faecal immunochemical tests, in combination with alternative endoscopy offers where resources allow. Furthermore, there is a large potential for increasing screening use in Europe by better reaching the younger eligible individuals, those who have not been to the doctor recently and those at increased risk for CRC.

An increasing proportion of colorectal cancers (CRCs) are detected through screening due to the availability of organised population-based programmes. We aimed to analyse survival probabilities of patients with screen-detected CRC in European countries. Data from CRC patients were obtained from 16 population-based cancer registries in nine European countries. We included patients with cancer diagnosed from the year organised CRC screening programmes were introduced until the most recent year with available data at the time of analysis, whose ages at diagnosis fell into the age groups targeted by screening. Patients were followed up with regards to vital status until 2016-2020 across the various countries. Overall and CRC-specific survival were analysed by mode of detection and stage at diagnosis for all countries combined and for each country separately using the Kaplan-Meier method. We included data from 228 134 patients, of whom 134 597 (aged 60-69 years at diagnosis targeted by screening in all countries) were considered in analyses for all countries combined. 22·3% (38 080/134 597) of patients had cancer detected through screening. Most screen-detected cancers were found at stages I-II (65·6% [12 772/19 469 included in stage-specific analyses]), while the majority of non-screen-detected cancers were found at stages III-IV (56·4% [31 882/56 543 included in stage-specific analyses]). Five-year overall and CRC-specific survival rates for patients with screen-detected cancer were 83·4% (95% CI 82·9-83·9) and 89·2% (88·8-89·7), respectively; for patients with non-screen-detected cancer, they were much lower (57·5% [57·2-57·8] and 65·7% [65·4-66·1], respectively). The favourable survival of patients with screen-detected cancer was also seen within each stage – five-year overall survival rates for patients with screen-detected stage I, II, III, and IV cancers were 92.4% (95% CI 91·6-93·1), 87·9% (86·6-89·1), 80·7% (79·3-82·0), and 32·3 (29·4-35·2), respectively. These patterns were also consistently seen for each individual country. Patients with cancer diagnosed at screening have a very favourable prognosis. In the rare case of detection of advanced stage cancer, survival probabilities are still much higher than those commonly reported for all patients regardless of mode of detection. Although these results cannot be taken to quantify screening effects, they provide useful and encouraging information for patients with screen-detected CRC and their physicians. This study was supported in part by grants from the German Federal Ministry of Education and Research and the German Cancer Aid.

Mammography screening has been shown to be able to reduce breast cancer mortality, leading most European countries to implement mammography‐based screening programmes. In our study, we analysed key characteristics of breast cancer screening programmes and mammography use in European countries. Information on screening programmes were obtained from the 2017 European Union (EU) screening report, websites from governments and cancer registries, and through literature search in PubMed (studies published up to 20 June 2022). Data on self‐reported mammography use in the past 2 years were obtained from Eurostat and had been derived from the European health interview survey (cross‐sectional survey), conducted in the 27 EU countries, Iceland, Norway, Serbia, Turkey and the UK in 2013 to 2015 and 2018 to 2020. Data were analysed for each country according to their human development index (HDI). By 2022, all included countries besides Bulgaria and Greece had introduced an organised mammography‐based screening programme; Romania and Turkey had only pilot programmes. Screening programmes differ substantially across countries, particularly in timing of implementation (e.g., in Sweden, the Netherlands before 1990; Belgium, France between 2000 and 2004; Denmark, Germany between 2005 and 2009; Austria, Slovakia after 2010). Self‐reported mammography use also differed considerably across countries, and went along with HDI—from <36% in all countries with HDI 70% in most countries with HDI >0.90. The data call for efforts to improve mammography screening use across Europe, particularly in countries with lower development levels where breast cancer mortality rates are also among the highest in the region.

Monitoring population-level colonoscopy and sigmoidoscopy use is crucial to estimate the future burden of colorectal cancer and guide screening efforts. We conducted a systematic literature search on colonoscopy and sigmoidoscopy use, published between November 2016 and December 2018 in the databases PubMed and Web of Science to update previous reviews and analyze time trends for various countries. In addition, we used data from the German and European Health Interview Surveys and the National Health Interview Survey to explore recent time trends for Germany and the US, respectively. The literature search yielded 23 new articles: fourteen from the US and nine from Australia, Canada, England, Germany, Saudi Arabia, and South Korea. Colonoscopy use within 10 years was highest and, apart from the youngest age groups eligible for colorectal cancer screening, kept increasing to levels close to 60% in the US and Germany. A recent steep increase was also observed for South Korea. Limited data were available on sigmoidoscopy use; regional studies from the US suggest that sigmoidoscopy has become rarely used. Despite high uptake and ongoing increase in the US, Germany, and South Korea, use of colonoscopy and sigmoidoscopy has either remained low or essentially unknown for the majority of countries.

Randomized trials on the effectiveness of screening endoscopy in reducing colorectal cancer (CRC) risk have reported statistically significant, but rather modest reduction of CRC risk by the screening offer. However, risk estimates in these trials included substantial proportions of prevalent CRC cases which were early detected, but could not possibly have been prevented by screening. Thereby, a key principle of randomized prevention trials is violated that only “at risk” persons who do not yet have the disease one aims to prevent should be included in measures of preventive effects. Using recently published data from the Nordic-European Initiative on Colorectal Cancer (NordICC) trial as an example, we illustrate that approaches aimed to account for “prevalence bias” lead to effect estimates that are substantially larger than those reported in the trial and more in line with results from observational studies and real life settings. More rigorous methodological work is needed to develop effective and user-friendly tools to prevent or adjust for prevalence bias in future screening studies.

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.