Limited-Duration Prevalence represents the proportion of people alive on a certain day who had a diagnosis of the
disease within the past x years (e.g. x = 5, 10 or 20 years). Registries of shorter duration, less than 40 or 50 years of
data collection, can only estimate
prevalence can be further classified into periods from year of diagnosis. Thus, the 20-years prevalence can be further classified
into the prevalence of those diagnosed in the last 0 to < 5 years, 5 to < 10 years, 10 to < 15 years, and 15 to < 20 years.
NCI's SEER Program has information
on cancer cases since 1973; however, prevalence calculations usually
begin in 1975 due to a different number of registries participating
in years 1973-1974. Thus a maximum of 30-year prevalence can be
estimated from SEER cases diagnosed from 1975 through 2004.
Limited-duration prevalence statistics can be calculated using the SEER*Stat