The combined effect of prevention, screening and intervention has been a steady decrease in adult mortality rates from the four major types of cancer in the USA since the early 1990s, but are the benefits spread evenly through society?

Writing in the Journal of the National Cancer Institute, Ahmedin Jemal and colleagues assessed the education and mortality data of black and white men and women who died between 1993 and 2001 from cancer of the lung, colon and rectum, prostate and breast and found that “the remarkable reduction in mortality...was confined largely to more highly educated men and women” (http://www.sciencedaily.com/ 9 Jul 2008). Death rates decreased in all groups with at least 16 years of education except for black women with lung cancer, but of the groups with less than 12 years of education only one (white women with breast cancer) showed a decrease, and two groups showed increasing mortality.

There are several possible explanations for these findings, including the higher prevalence of cancer risk factors such as smoking and obesity in less-educated groups. The difference in access to health care is important, as the disparities between the groups are often not observed for diseases that have no effective treatment. “It's only when we develop an intervention that disparities appear,” observes Dr Alfred Neugut of Columbia University (http://health.usnews.com/ 8 Jul 2008).

More-educated people may also be more likely to get appropriate screening tests: “They are better at taking advantage of what's learned by society in regard to health care,” Neugut said (http://health.usnews.com/ 8 Jul 2008). Targeting health-care provision and information about screening and intervention to lower socioeconomic groups may be necessary to ensure the benefits of cancer research are enjoyed by all.