Exploring individual and contextual determinants of cancer prevention behaviour change in the European Union: a qualitative study to inform implementation of the European Code Against Cancer

Background: Cancer prevention is central to Europe's Beating Cancer Plan (ECBP), with the European Code Against Cancer (ECAC) providing evidence-based recommendations to reduce cancer risk. The fourth edition (ECAC4) focuses on individual behaviour change, but effective implementation requires insight into individual and structural factors influencing adoption. We explored barriers and facilitators to adopting ECAC4 recommendations across nine EU Member States to inform the forthcoming edition. Methods: An exploratory multi-country qualitative study with 141 adults aged 18-65 years, with no prior cancer diagnosis, from Bulgaria, Croatia, France, Germany, Ireland, Poland, Portugal, Romania, and Spain was conducted. Semi-structured interviews examined perceived capability, opportunity, and motivation related to the 12 ECAC4 recommendations. Transcripts were translated, coded, and thematically analysed using ATLAS.ti, with high intercoder agreement (κ = 0.88). Themes were mapped onto the COM-B and Theoretical Domains Framework (TDF) to identify behavioural determinants. Findings: Barriers and facilitators were identified across all COM-B domains. Capability barriers included low health literacy, misinformation, and limited self-management skills; facilitators included early health education and reliable information. Opportunity barriers encompassed cultural norms, economic constraints, environmental limitations, and healthcare access issues; facilitators included supportive social networks, universal healthcare, and enabling policies. Motivation barriers involved entrenched habits and fear, while facilitators included personal health goals, family responsibilities, and determination. Interpretation: Adoption of ECAC4 recommendations is shaped by interlinked individual, social, and structural determinants. Multi-level implementation strategies, improving health literacy, ensuring equitable access, strengthening supportive environments, and tailoring motivational approaches, are essential. These findings directly inform ECAC5 and support the objectives of ECBP. Funding: This project was funded by the Cancer Prevention Europe (CPE) consortium and additionally supported by the budget of IARC's Environment and Lifestyle Epidemiology Branch.