Racial disparities increasing for cancers unrelated to smoking

A new American Cancer Society study finds that recent progress in closing the gap in overall cancer mortality between African Americans and whites may be due primarily to smoking-related cancers, and that cancer mortality differences related to screening and treatment may still be increasing.

The study, appearing in the November issue of Cancer Epidemiology Biomarkers and Prevention, is the first to analyze racial and ethnic differences between the two broad categories of disease.

Despite decreases in overall cancer death rates across all racial and ethnic groups since the early 1990s, racial disparities in cancer mortality persist. African Americans have the highest risk of all major ethnic groups in the United States of being diagnosed with and dying of cancer. The researchers examined how black-white disparities have in cancer mortality have changed over time for all sites combined, for smoking-related cancers, and for sites affected, or potentially affected by screening and treatment (breast, prostate, colon/rectum).

Data from the National Center for Health Statistics showed the black-white disparity in overall cancer death rates narrowed from the early 1990s through 2004, especially in men. But analysis showed that reduction was driven predominantly by more rapid decreases in mortality from tobacco-related cancers in black men than white men. In contrast, racial disparities in mortality from cancers potentially affected by screening and treatment increased over most of the time intervals since 1975.

The study found death rates from lung and other smoking-related cancers in black and white men began to converge in the early 1990s, approximately 15 years after the prevalence of current cigarette smoking began to decrease more rapidly in black than white men. The convergence of death rates from smoking-related cancers other than lung cancer began somewhat earlier and was larger in proportionate terms than the pattern seen for lung cancer. But the trends for related to screening and treatment were notably different. For those, the decreases in death rates began earlier and have been larger in proportionate terms for whites than for African Americans.

"Racial disparities in cancer mortality have decreased for tobacco related cancers but continue to increase in relative terms for those cancer sites related to screening and treatment," write the authors. "The goal of eliminating racial disparities in cancer mortality cannot be achieved without coordinated and sustained efforts to provide high quality prevention, screening and treatment to all segments of the population."

Article: DeLancey JO, Thun MJ, Jemal A, Ward EM. "Recent Trends in Black-White Disparities in Cancer Mortality - Cancer Epidemiology Biomarkers and Prevention, November 1, 2008