1 Testosterone and its active metabolite.

Dihydro-testosterone are essential for prostate cancer to develop, but does not actually cause prostate cancer. Men who are castrated at a young age do not develop prostate cancer.

2 Prevalence of prostate cancer

One in ten men will develop clinically significant prostate cancer in their lifetime. It is the most commonly diagnosed cancer in American males with 250 000 new cases reported annually. Prostate cancer is second only to lung cancer as a cause of cancer death in both the USA and the UK. Prostate cancer is rare among Orientals. It is more common in black than white Americans. The disease appears to present at a younger age and behave more aggressively in American blacks. Prostate cancer is common in South Africa and probably underreported as a cause of death. The exact incidence in South Africa is not known as no large-scale epidemiological studies have been performed. It is uncertain whether prostate cancer is more common in South African blacks as compared to whites. In very old men prostate cancer is not always clinically significant. Autopsy data indicate a 70% incidence of prostate cancer in 80 year old men. The majority of these men died with rather than from prostate cancer.

3 Causes of prostate cancer

There is no single cause of prostate cancer. The cancer originates in the epithelial cells of the glandular elements of the prostate. As with most cancers defects in the DNA of the cell are central to the development of prostate cancer. Multiple DNA defects are required for cancer to develop. This multi-step process takes place over time. Some defects can be inherited, while others are acquired during the patient's lifetime. Prostate cancer is exceedingly rare before the age of 40, but 1 in 8 men between the ages of 60 and 80 years suffer from the disease. 9% of all prostate cancers are caused by a genetic susceptibility, probably inherited via chromosome 1. These genetically related cancers tend to present at a relatively younger age.

4 What is prostatitis?

Prostatitis means