This WG brings together registries, researchers, research funders, data sharing experts, and key federal stakeholders to discuss requirements, challenges, and solutions related to secondary sharing of cancer registry data, including sharing into data repositories or use in consortium pooling studies. The goal is to better understand the data sharing issues, identify solutions that support the NIH Data Sharing Policy, maximize the impact of registry data, and support NIH-funded cancer researchers while ensuring adequate protection of the registry data.