Skin color and cancer mortality among black men in the Charleston Heart Study

Abstract

The association between skin color and 30-year cancer mortality in a random sample of black men and a peer-nominated group of high socioeconomic status (SES) black men was evaluated in the Charleston Heart Study, a prospective study, begun in 1960, designed to investigate the epidemiology of coronary heart disease in a biracial cohort. Skin color was used as a continuous variable and as a categorical variable, by tertiles, in a Cox proportional hazards regression model. In the high SES group, there was a statistically significant decreasing relationship between skin color and cancer mortality, with those having the lightest skin having the lowest cancer mortality. In the random sample of black men, the relationship between skin color and cancer mortality was not statistically significant; however, the data indicated a slight protective effect among those with the lightest skin color. Because degree of skin reflectance is a measure of black-white admixture, these results may indicate a genetic mechanism underlying the differences in cancer mortality across skin color groups. Skin color is also recognized as a marker for psychosocial factors. Therefore, poor prognosis among those with darker skin color as a result of failure of early detection, inadequate treatment, and a variety of psychosocial stressors represents an alternative explanation of the study findings.