Cancer prevalence estimates the number of people alive on a certain date who have been diagnosed with cancer. These estimates provide a measure of the burden of cancer diagnoses on the population and are often used for planning and resource allocation, evaluating the overall success of cancer treatment in preventing cancer mortality, and quantifying the cancer survivorship population.
Prevalence can be calculated using different methods with respect to the tumor inclusion selection criteria.1 The Texas Cancer Registry (TCR) provides estimates for both the first invasive tumor ever and the first invasive tumor per site. In the first invasive tumor per site calculations, a person with multiple tumors can contribute to different site-specific prevalence estimates but will only contribute once to the “All Sites” estimate; thus, the sum of the prevalence by cancer site will be greater than the prevalence of "All Sites." In the first invasive tumor ever calculations, only a person’s first diagnosed tumor will contribute to the site-specific estimates and the “All Sites” estimate. For example, if a man had a diagnosis of colon cancer prior to prostate cancer, his colon cancer would contribute to the prevalence of colon cancer and the “All Sites” estimate, but the prostate cancer would not contribute to the prostate cancer prevalence estimate.
TCR examines 5-year and 24-year2 limited duration prevalence using the counting method, in which the number of people alive on the prevalence date (January 1, 2019) who had a diagnosis of cancer within the previous X years (e.g., 5 or 24 years) is calculated. This method adjusts for people who may have been lost to follow-up by estimating the probability of being alive at the prevalence date from an appropriate survival function stratified by sex, cancer site, year of diagnosis, age at diagnosis, and race. Please review the footnotes in the prevalence table carefully as they contain additional information about the estimates.
1 For more information about cancer prevalence statistics, including methods, approaches to estimation, tumor inclusion criteria, and limited duration prevalence, please see: surveillance.cancer.gov/prevalence/
2 TCR data are complete for diagnosis years 1995 through the most recent certification year. Therefore, 24 years represents the full history of complete data for TCR through the prevalence date of January 1, 2019 (all cases diagnosed from 1995 through 2018).