Cancer surveillance refers to the systematic collection, analysis, interpretation, and dissemination of cancer data. This data includes information on the incidence, prevalence, and mortality of various types of cancer in a given population. The goal of cancer surveillance is to monitor trends, identify high-risk populations, guide public health policies and interventions, and evaluate the impact of prevention and treatment programs. Surveillance data is typically collected from cancer registries, medical records, population-based surveys, and other sources, and is used by researchers, health officials, and policymakers to track the burden of cancer and inform decision-making in healthcare.