This study, conducted at Korle-Bu Hospital in Accra, Ghana, will help elucidate the roles of lifestyle and genetic factors in prostate cancer risk. There is a strong variation in risk of prostate cancer throughout the world. The rates of the disease among African Americans are some of the world's highest. In the United States, the incidence of prostate cancer is 70 percent higher in African Americans than in white Americans and the death rate in African Americans is almost double that of white Americans. The reasons for this excessive risk are unknown, but both genetic and lifestyle factors have been suggested.

Because Africans and African Americans share similar genetic ancestry but have vastly different lifestyles, a better understanding of the rates and risk factor profiles for prostate cancer among Africans will provide important clues to what causes the disease. This study will try to assess the incidence of prostate cancer in the West African nation of Ghana. The study has two components:

• Clinical survey - The methods of diagnosis at Korle-Bu will be evaluated and the incidence of prostate cancer over a 5-year period will be estimated.
• Screening and detection survey - A survey of 1,000 men between 50 and 74 years of age will estimate the prevalence of both asymptomatic and undiagnosed symptomatic prostate cancer in the Accra population.

The clinical survey will use data from the cancer logbook and medical records at Korle-Bu Hospital and the Ghanaian National Census to derive an estimate of prostate cancer incidence within Accra. The estimate will be low, since it will be based only on men diagnosed or treated at Korle-Bu and will not include men with asymptomatic disease, men diagnosed elsewhere, or men without access to medical care. The screening and detection survey will assess the presence of asymptomatic and unrecognized symptomatic prostate cancer using PSA testing and digital rectal examination in a random sample of 1,000 men in the general population of Accra. This will provide a high estimate of disease prevalence. The two estimates will provide an approximation of the true incidence rate of the disease in Accra.

Comparison of these data with similar data from community surveys of African Americans will provide insight into reasons for the excess risk of prostate cancer in African Americans.