Ethnic differences in cancer mortality trends in the US, 1950-1992

Objective. To describe long-term mortality trends by ethnicity, sex, and ag e for selected cancers and to assess the effect of age-adjustment using dif ferent standard populations on rate ratios and rate differences comparing b lack to white cancer mortality. Design. Mortality rates for selected cancers were obtained from published r eports of the Vital Statistics of the United States (1950-1992). All ethnic - and sex-specific cancer rates were directly age-adjusted to the total 197 0 US standard population and to a subset of the 1970 US standard population 40 years and older. Results. Over a 42-year period, lung cancer mortality increased in all popu lation subgroups. Colorectal cancer mortality declined in whites, but incre ased in blacks. Prostate cancer mortality increased slightly in white men, but dramatically increased in black men. Breast cancer mortality stabilized in white women, but increased markedly in black women. Uterine cancer mort ality declined for both ethnicities, while ovarian cancer mortality rates i ncreased for both ethnicities. As expected the ratios of the age-adjusted c ancer mortality rates comparing blacks to whites were the same regard less of the age structure used as the standard population. In contrast, the diff erences in the age-adjusted rates between blacks and whites were greater wh en the age-truncated standard population was used. Conclusions. There are unexplained ethnic differences in the long-term mort ality trends of selected cancers. Of particular concern are the increasing death rates in black individuals from colorectal, prostate, breast, and ova rian cancers. Since almost all deaths from these cancers occur in persons o ver 40, age-adjustment using an age-truncated standard population that incl udes only those age groups at risk should be considered, particularly when the question to be addressed is one dealing with the impact of a characteri stic, such as ethnicity or sex, on mortality risk.