PROJECT SUMMARY Background: The influence of the outer context, i.e., the macro-level historical, cultural, economic, and political forces that shape implementation, is important to consider when developing and implementing evidence-based programs and policies to prevent and control cancer. While the outer context has received less attention within implementation science than the inner context of implementing organizations, accounting for it can improve work focused on advancing health equity. Goal: The goal of this competitive supplement is to conduct an environmental scan of the outer context of each of the ISC3 centers, compile outer contextual factors into a database, and use the information gathered to develop new, cross-center pilot projects. Additionally, we propose to develop and evaluate findings specific to the Washington University in St. Louis Implementation Science Center for Cancer Control to our Implementation Laboratory in a manner that is relevant to our community stakeholders. Methods: Aim 1: Characterize the outer context of the ISC3 network and assess its relationship with cancer prevention and control indicators. We will work alongside the other centers in the ISC3 network to finalize measures representing key features of the outer context, in order to characterize the outer context related to equity in cancer prevention and control. We will contract with HealthLandscape to collect these data from existing national data sources and compile them into a common database for use across the network. Also, we will examine the relationship between outer context and cancer prevalence, cancer-related behaviors, and policies across the ISC3 network. Aim 2: Disseminate information about the outer context of the WU-ISC3 to our community partners. We will develop community snapshots to summarize the findings about the outer context specific to the WU-ISC3 community (i.e., 82-county catchment area served by the Siteman Cancer Center). We will evaluate our stakeholders’ (e.g., representatives from community organizations, clinicians, community members) opinions about the usefulness of these snapshots through a survey and in-depth interviews. Feedback from our stakeholders will be used to refine dissemination materials and ensure their relevance to our Center’s stakeholders. Innovations and impact: The proposed work will result in the compilation of the first set of common data elements collected across all ISC3 centers and will facilitate future cross-center collaborations to improve the implementation of evidence-based programs and policies for cancer prevention and control and health equity.