Background: Although both race and socioeconomic status are well known to influence mortality patterns in the United States, few studies have examined the simultaneous influence of these factors on cancer incidence and mortality. We examined relationships among race, education level, and mortality from cancers of the lung, breast, prostate, colon and rectum, and all sites combined in contemporary US vital statistics.
Methods: Age-adjusted cancer death rates (with 95% confidence intervals [CIs]) were calculated for 137,708 deaths among 119,376,196 individuals aged 25-64 years, using race and education information from death certificates and population denominator data from the US Bureau of the Census, for 47 states and Washington, DC, in 2001. Relative risk (RR) estimates were used to compare cancer death rates in persons with 12 or fewer years of education with those in persons with more than 12 years of education.
Results: Educational attainment was strongly and inversely associated with mortality from all cancers combined in black and white men and in white women. The all-cancer death rates were nearly identical for black men and white men with 0-8 years of education (224.2 and 223.6 per 100,000, respectively). The estimated relative risk for all-cancer mortality comparing the three lowest (< or = 12 years) with the three highest (> 12 years) education categories was 2.38 (95% CI = 2.33 to 2.43) for black men, 2.24 (95% CI = 2.23 to 2.26) for white men, 1.43 (95% CI = 1.41 to 1.46) for black women, and 1.76 (95% CI = 1.75 to 1.78) for white women. For both men and women, the magnitude of the relative risks comparing the three lowest educational levels with the three highest within each race for all cancers combined and for lung and colorectal cancers was higher than the magnitude of the relative risks associated with race within each level of education, whereas for breast and prostate cancer the magnitude of the relative risks associated with race was higher than the magnitude of the relative risks associated with level of education within each racial group. Among the most important and novel findings were that black men who completed 12 or fewer years of education had a prostate cancer death rate that was more than double that of black men with more schooling (10.5 versus 4.8 per 100,000 men; RR = 2.17, 95% CI = 1.82 to 2.58) and that, in contrast with studies of mortality rates in earlier time periods, breast cancer mortality rates were higher among women with less education than among women with more education (37.0 and 31.1 per 100,000, respectively, for black women and 25.2 versus 18.6 per 100,000, respectively, for white women).
Conclusion: Cancer death rates vary considerably by level of education. Identifying groups at high risk of death from cancer by level of education as well as by race may be useful in targeting interventions and tracking cancer disparities.