Hermann Brenner,Thomas Heisser,Michael Hoffmeister
{"title":"Looking at randomized trials with the critical eyes of epidemiologists: the case of screening colonoscopy.","authors":"Hermann Brenner,Thomas Heisser,Michael Hoffmeister","doi":"10.1007/s10654-025-01269-y","DOIUrl":null,"url":null,"abstract":"Based on compelling evidence from observational epidemiological studies, screening colonoscopy has since long been thought to strongly lower the burden of colorectal cancer (CRC), both by early detection of prevalent CRC and prevention of incident CRC through detection and removal of precancerous lesions. Widespread offer and use of screening colonoscopy went along with a dramatic decline in CRC incidence in screening age groups in the US, in contrast to an increase in incidence at younger ages and in countries not engaging in CRC screening. The recently published 10-year results from the NordICC trial, the first randomized clinical trial (RCT) reporting long-term effects of screening colonoscopy on CRC risk and mortality, has been widely interpreted as challenging the evidence for strong efficacy of screening colonoscopy. Such reasoning was based on the trust that randomization in this large-sized trial should have prevented any residual confounding that might have affected the observational epidemiological studies. However, randomization cannot prevent other potential biases which should be carefully addressed and minimized in both observational and interventional studies. We illustrate that such biases may have led to major underestimation of screening effects in the NordICC trial. The observed patterns underline the need for more rigorous efforts to prevent and correct for such biases, along with the need to derive more informative metrics of screening efficacy. Such metrics should include informative estimates of screening colonoscopy effects on both early detection of prevalent CRC cases and prevention of incident CRC cases. The momentum for CRC screening should by no means slowed by misinterpretation of the NordICC trial evidence.","PeriodicalId":11907,"journal":{"name":"European Journal of Epidemiology","volume":"3 1","pages":""},"PeriodicalIF":5.9000,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"European Journal of Epidemiology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1007/s10654-025-01269-y","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PUBLIC, ENVIRONMENTAL & OCCUPATIONAL HEALTH","Score":null,"Total":0}
引用次数: 0
Abstract
Based on compelling evidence from observational epidemiological studies, screening colonoscopy has since long been thought to strongly lower the burden of colorectal cancer (CRC), both by early detection of prevalent CRC and prevention of incident CRC through detection and removal of precancerous lesions. Widespread offer and use of screening colonoscopy went along with a dramatic decline in CRC incidence in screening age groups in the US, in contrast to an increase in incidence at younger ages and in countries not engaging in CRC screening. The recently published 10-year results from the NordICC trial, the first randomized clinical trial (RCT) reporting long-term effects of screening colonoscopy on CRC risk and mortality, has been widely interpreted as challenging the evidence for strong efficacy of screening colonoscopy. Such reasoning was based on the trust that randomization in this large-sized trial should have prevented any residual confounding that might have affected the observational epidemiological studies. However, randomization cannot prevent other potential biases which should be carefully addressed and minimized in both observational and interventional studies. We illustrate that such biases may have led to major underestimation of screening effects in the NordICC trial. The observed patterns underline the need for more rigorous efforts to prevent and correct for such biases, along with the need to derive more informative metrics of screening efficacy. Such metrics should include informative estimates of screening colonoscopy effects on both early detection of prevalent CRC cases and prevention of incident CRC cases. The momentum for CRC screening should by no means slowed by misinterpretation of the NordICC trial evidence.
期刊介绍:
The European Journal of Epidemiology, established in 1985, is a peer-reviewed publication that provides a platform for discussions on epidemiology in its broadest sense. It covers various aspects of epidemiologic research and statistical methods. The journal facilitates communication between researchers, educators, and practitioners in epidemiology, including those in clinical and community medicine. Contributions from diverse fields such as public health, preventive medicine, clinical medicine, health economics, and computational biology and data science, in relation to health and disease, are encouraged. While accepting submissions from all over the world, the journal particularly emphasizes European topics relevant to epidemiology. The published articles consist of empirical research findings, developments in methodology, and opinion pieces.