Cancer prevalence is defined as the number or percent of people alive on a certain date in a population who previously had a diagnosis of the disease. It includes new (incidence) and pre-existing cases, and is a function of both past incidence and survival. Information on prevalence can be used for health planning, resource allocation, and an estimate of cancer survivorship. Overview of Cancer Prevalence Statistics contains a description of the types of and methodology for calculating prevalence statistics.

NCI has a variety of published reports and research tools for finding prevalence statistics.

For definitions of statistics-related terms, see the Glossary of Statistical Terms.