Results of an American study support the theory of a rather strong genetic influence on risk of prostate cancer. The study compared patterns of prostate cancer among black and white men (Chu et al., 2003). Black Americans had substantially higher prostate cancer rates than white Americans, but the longitudinal trends such as decreasing mortality, increasing incidence and survival were similar. Although this was not a typical migrant study, it compared different ethnic and thus genetic and lifestyle factors in a known risk pattern environment
