Multiplying the age-adjusted rate by 100,000 expresses it as the number of cases per 100,000 persons. The standard population used for age adjustment on this website is the 1970 United States population. Summary The cancer incidence rate is defined as the number of new cases per 100,000 persons. Small numerators and denominators as well as small changes in the numerator may result in a large amount of variability in incidence rates. Caution is advised in the interpretation of rates and comparisons because sources of variability have not been accounted for.
Unmeasured variation includes measurement error and sampling error.
Confounding factors, which may obscure differences in rates, have also not been incorporated into estimates presented in this report.