Prostate Cancer in African-American Men
Excerpt from a report from the National Cancer Institute's (NCI) Cancer Information Service - Published May 1998
NCI-supported researchers conducted a case-control study of prostate cancer among men in the United States and Canada who are at high risk (African-Americans), moderate risk (whites), and low risk (Asian-Americans) for the disease. The study assessed the contributions of diet, physical activity, and body size to the observed ethnic differences in risk.
Although researchers found no consistent evidence of a relationship between prostate cancer risk and either body mass or physical activity, increased risk of prostate cancer was found to be associated with high intake of saturated fat in each of the ethnic groups studied. Other factors such as genetically determined hormone levels and diet during adolescence may account for differences in incidence among the ethnic groups studied.
Five-year survival rates are lower for African-American men (66.4 percent during 1983 to 1990) than for white men (81.3 percent during 1983 to 1990). This difference is due, in part, to the fact that African-American men tend to be diagnosed at later stages of the disease. But, even within stages, survival rates are lower for African-Americans.
African-American men have considerably higher incidence rates (209.6 cases per 100,000 African-American men in 1991) than white men (159.2 cases per 100,000 white men in 1991).
African-American men may have the highest rate of prostate cancer incidence in the world. In addition, their prostate cancer mortality rate is twice as high as the rate for white Americans. In 1991, mortality rates were 24.7 cases per 100,000 white men, and 55.1 cases per 100,000 African-American men. Mortality rates also are increasing much more rapidly among African-American men (about 1.8 percent annually from 1973 to 1991) than among whites (about 1.0 percent annually).
The causes of higher rates of prostate cancer among African-American males are largely unknown. An NCI study found that even when income and education are controlled for, African-Americans have much higher rates than whites. An NCI-supported study is being conducted in three areas of the United States to investigate the reasons for African-Americans' high rates of prostate cancer and other cancers. This case-control study will examine the impact of a wide variety of potential risk factors, including dietary and other lifestyle differences, occupational exposures, and hormonal and genetic differences.