Which statistic can be used to compare cancer incidence across different population age groups?

The standardized rate is the appropriate statistic for comparing cancer incidence across different population age groups because it accounts for differences in age distribution among populations. This measure adjusts the incidence rates to a common age structure, allowing for a fair comparison between groups that may have varying age demographics.

When populations have disparate age distributions, a raw comparison of incidence rates could be misleading, as cancer risk generally varies significantly with age. By using standardized rates, epidemiologists can eliminate the confounding effects of age, providing a clearer picture of cancer incidence that reflects the underlying risk rather than the differences in age structures.

This standardization process involves applying age-specific rates for the cancer of interest to a standard age distribution, which results in a summary measure that can be directly compared across different populations or groups, irrespective of their actual age distribution.