Prevalence Projections Table
Purpose: Provide a table of breast cancer prevalence projections for use in assessing
the burden for the US by state.
Cancer prevalence represents persons alive at a given date who were previously diagnosed with cancer. This web site provides estimates and projections of cancer prevalence for all 50 U.S. states and the District of Columbia (D.C.), based on a statistical method that uses state-specific mortality data and cancer survival. The prevalence statistics presented are prevalence counts, prevalence percents and age-adjusted prevalence percents. For an overview of methods and definitions refer to http://surveillance.cancer.gov/software/prevalence.html. Incidence differs from prevalence in that it represents new cancer cases diagnosed during a given period of time, usually a year.
Complete Prevalence includes all people alive diagnosed with cancer regardless of how long ago the diagnosis was and represents cancer survivorship.
5-year Limited Duration Prevalence (also known as 5-year prevalence) includes people alive diagnosed with cancer within the past 5 years. It is a closer assessment of cancer patients’ prevalence in more intensive cancer care.
Prevalence Counts - number of people alive in a given date previously diagnosed with cancer.
Crude Prevalence Percent - percent of the population alive and previously diagnosed with cancer.
Age-Adjusted Prevalence Percent – A weighted average of the age-specific prevalence percent, where the weights are the proportions of persons in the corresponding age groups of a standard million population
Method of estimation and data sources:
Calculation of complete cancer prevalence requires several years of incidence data and accurate vital status information at end of follow-up.
Five states from the Surveillance, Epidemiology, and End Results (SEER) program (http://seer.cancer.gov) have cases diagnosed from 1975 and allow estimation 30-year limited duration prevalence which is close to complete.
Fewer years of cancer incidence are available from states funded by SEER and/or the CDC National Program for Cancer Registries (NPCR) (http://www.cdc.gov/Cancer/npcr/).
Gaps in data collection prevent the calculation of cancer prevalence for many states. A statistical model is used that predicts cancer prevalence1 from state specific cancer mortality data from National Center of Health Statistics (NCHS) and cancer survival model2 adjusted to represent cancer survival in each respective state. The method has been validated against reported incidence cases for 37 states from SEER and NPCR.
1. Breast cancer survivors in the US States: geographical variability and time trends 2005-2015 De Angelis R, Tavilla A, Verdecchia A, Feuer EJ, Mariotto AB. Submitted to Cancer.
2. Mariotto A, Capocaccia R, Verdecchia A, Micheli A, Feuer EJ, Pickle L et al. Projecting SEER Cancer Survival Rates to the US: An Ecological Regression Approach. Cancer Causes and Control 2002; 13(2):101-111.