Elements of screening and early diagnosis of lower GI neoplastic lesions – an overview

Dobrow's 12 consolidated principles were applied to evaluate the extent to which colorectal cancer (CRC) screening programmes align with these established screening principles. The principles within the first domain - disease and conditions - are fully met. CRC represents a significant global public health burden with a well-understood natural history, including a long preclinical phase. These features make CRC suitable for population-based screening. Current guidelines recommend screening average-risk individuals, with starting ages as early as 45 years and stopping ages up to 85 years in some programs, although most programs target those aged 50-75 years. For Dobrow's second domain - test or intervention - we found that established CRC screening methods (faecal immunochemical testing (FIT), colonoscopy, and flexible sigmoidoscopy) have known and acceptable sensitivity and specificity. These tests have clear thresholds for interpretation and follow-up and are associated with reductions in both CRC incidence and mortality, confirming their clinical effectiveness in organised programmes. Dobrow's third domain - programme or system - addresses how screening programmes should be structured, implemented, and integrated into health systems. Unlike the other domains, this is fully achieved in only a small minority of programmes. While implementation may vary from country to country, the principles provide benchmarks for well-organised programmes. CRC screening is generally cost-effective and widely accepted by patients, providers, and society. Successful programmes require dedicated teams, infrastructure, and systems for coordination and quality assurance. Before implementation, a CRC screening initiative must meet, or have a clear plan to meet 12 principles. In summary, robust infrastructure and governance are essential for organised CRC screening programmes to align with the Dobrow principles and achieve long-term success.