Cancer registries have proven valuable with respect to validating therapeutic safety and drug efficacy, uncovering real-world implementation practices, and their evolution over time. Modern cancer therapeutics are approved as single agents oftentimes compared to the least active approved standard agent in randomized trials. However, the burgeoning diversity and number of drugs introduces a complexity that quickly outstrips the knowledge provided by these pivotal trials. This gap in information is particularly relevant when survival is the primary therapeutic endpoint. In addition, the inherent complexity of the immune response will make registries a particularly important tool in expeditiously understanding solid tumor immunotherapy and patient outcomes.