Objectives of study: To test recent claims that cancer inequities are bound to increase as population health improves.
Methods: We analyzed 1960-2006 age-standardized US county cancer mortality data, total and site-specific (lung, prostate, colorectal, breast, cervix, stomach), stratified by county income quintile for the US total, black, and white populations.
Results: Between 1960 and 2006, US socioeconomic inequities in cancer mortality variously shrunk, widened, reversed, and stagnated, depending on time period and cancer site. For all cancers combined and most, but not all, sites, absolute, but not relative, socioeconomic gaps were greater for the black compared to white population. Compared to the yearly age-specific mortality rates among whites in the most affluent counties, the percent of excess cancer deaths among whites in the lower four county income quintiles first rose above 0 in 1990 and in 2006 equaled 5.4% (95% CI 4.8, 6.0); among blacks, it rose from 6.0% (95% CI 4.5, 7.4) in 1960 to 24.7% (95% CI 23.9, 25.5) in 1990 and remained at this level through 2006.
Conclusions: The hypothesis that cancer mortality inequities are bound to increase is refuted by long-term data on total and site-specific cancer mortality stratified by socioeconomic position and race/ethnicity.