Racial and SES disparities exist across the continuum of disease and the needed research needs to give greater attention to identifying both the determinants of disparity and the optimal intervention strategies at each specific point of the disease continuum. A study by Wong et al173 examined the contribution of the risk factors that predicted disparities in cancer incidence, stage at diagnosis and survival after diagnosis to disparities in life expectancy. It found that across all cancers combined, differences in cancer incidence contributed more to racial differences in cancer mortality than the differences in cancer stage or survival after diagnosis. For example, for lung cancer among men, incidence accounted for almost half of a year difference in life expectancy – that is more than the impact of stage and survival after diagnosis of all cancers combined. This has important implications for the design and targeting of interventions for lung cancer. It indicates, for example, that smoking cessation may be an especially effective strategy to reduce racial disparities in cancer mortality among men. A similar pattern of the primacy of social risks
