PROSTATE CANCER

There are unexplained differences in the incidence of cancer of the prostate in different parts of the world: it is relatively uncommon in men of Japanese and Indian ancestry, and more common in those of African ancestry. It is twice as common in men of African-American descent and is more likely to present at an advanced stage. The number of reported cases seems to be increasing, but this may be due to an increased awareness, the growing number of elderly men who are surviving, and better ways of making the diagnosis.

Introduction of the PSA blood test in the late 1980’s enhanced prostate cancer detection. A dramatic increase in the detection rate in the early 1990’s was followed by a subsequent decline and was thought to be due to detection of early small tumours. Cancer which is found by an elevated PSA or a prostate nodule on digital rectal examination is referred to as a clinical cancer. Cancer found only at autopsy is called a latent tumour. However the total annual number of new cases shows an increase and this is frequently interpreted in an alarmist way to justify programmes of screening.