CancerWatch: accelerating Europe’s cancer intelligence

CancerWatch: strengthening Europe's cancer intelligenceCancer remains one of Europe's most pressing public health challenges, with 2.7 million new cases and 1.3 million deaths estimated each year [1].By 2050, cancer incidence and mortality are projected to rise by 20.4% and 34.6% respectively, while per-capita cancer spending across the EU27 is forecast to increase by 59% in real terms over the same period [2, 3].Population ageing, persistent inequalities and rising costs are expected to increase pressure on European health systems [4,5].Assessing this growing burden and evaluating the effectiveness of cancer control therefore require timely, comparable and robust population-based evidence.In 2021, the European Commission launched Europe's Beating Cancer Plan (EBCP), supported by €4 billion to strengthen cancer control [6].Its four action areas cover prevention, early detection, diagnosis and treatment, and quality of life of all patients and survivors.However, a recent assessment by the European Court of Auditors found that the EBCP monitoring framework lacks quantified targets, milestones and indicators, highlighting the need for harmonised and comparable population-based data to assess progress and impact [7]. Population-based cancer registries: a foundation for cancer intelligencePopulation-based cancer registries (PBCRs) provide systematic, continuous and standardised real-world evidence on cancer across Europe.Their cancer collection draws on multiple data sources, harmonised coding and standardised analytical methods that follow international recommendations, supporting quality and comparability across populations [8][9][10][11].Unlike hospital-based or medico-administrative datasets, PBCRs capture core clinical information on all incident cancers within a defined population, irrespective of where patients are diagnosed or treated.This population-wide coverage is essential for more comprehensive and less selection-prone assessment of patient-centred cancer incidence, survival and other populationlevel outcomes.The Lancet Commission identified PBCRs as essential for evaluating cancer control policies and supporting population-based research [12].The reliability of PBCR data is commonly assessed through four competing dimensions: completeness, validity, comparability and timeliness [13,14].Maintaining high performance across all four remains challenging, particularly as demand for more timely cancer data increases.Beyond surveillance, PBCRs support population-based research on cancer aetiology, survival, inequalities and healthsystem performance.PBCRs are also essential for monitoring key cancer-control objectives across the entire cancer patient pathway.For example, they enable evaluation of organised screening programmes through indicators such as stage at diagnosis, interval cancers, survival and mortality, providing evidence of population-level effectiveness.Similarly, the target