The Primary Cancer Prevention – Implementation Toolkit (PCP-IT) is being implemented by different teams in 8 European countries: Spain, the Netherlands, Albania, the United Kingdom, Italy, Ukraine, Germany, and Ireland. By taking advantage into ongoing implementation and upscaling activities (including a broad range of settings and interventions) PIECES achieves an extensive multi-site case-comparison study to explore the causal contribution and attribution of PCP-IT to the observed implementation outcomes.