Age and Ethnicity

• Age

Primarily a disease of the elderly, the most significant risk factor for developing prostate cancer is age. Globally, three-quarters of prostate cancer cases occur in men over the age of 65 and it follows that, as the world’s population ages, the number of men diagnosed with prostate cancer is set to increase.

Prostate cancer is often found in autopsy studies. The vast majority of these men are never diagnosed with the disease and it does not cause their death. Also, large proportions of men diagnosed with prostate cancer never actually develop clinical symptoms, and don’t experience a reduction in lifespan as a result of the disease. This is commonly described as latent prostate cancer .

One of the biggest challenges facing researchers is to discover whether it is possible to distinguish between men who have a latent form of prostate cancer, and men with a more aggressive (fast-growing) form of the disease.

• Ethnicity

Prostate cancer incidence varies between different ethnic groups, with the highest incidence found in the African-American population, and the lowest in South-east Asian populations; Northern and Western European populations show intermediate incidence rates. It is not known how much of this variety is due to environmental or dietary factors, and how much is due to genetic differences.

Japan has one of the lowest rates of prostate cancer mortality . This rate is increasing; and men who have migrated from Japan to America also develop an increased prostate cancer risk. Many researchers believe this supports a role for environmental and dietary risk factors in promoting prostate cancer development, and point to the ‘Westernisation’ of many Asian populations, with its associated changes in lifestyle and diet.