Understanding prostate cancer - the basics

What is prostate cancer?

The prostate is a gland in the male reproductive system that produces the majority of fluid that makes up semen, the thick fluid that carries sperm. The walnut-sized gland is located beneath a man's bladder and surrounds the upper part of the urethra, the tube that carries urine from the bladder. Prostate function is regulated by testosterone, a male sex hormone produced mainly in the testicles.

Prostate cancer is a major health concern for men in the UK. Although the disease is rare before age 50, experts believe that most elderly men have at least traces of it.

The PSA screening test

Prostate-specific antigen (PSA) is a substance produced by the prostate gland. Elevated PSA levels may indicate prostate cancer or a non-cancerous condition such as prostatitis or an enlarged prostate.

Just as important as the PSA number is the trend of that number (whether it is going up, how quickly, and over what period of time). It is important to understand that the PSA test is not perfect. Most men with elevated PSA levels have non-cancerous prostate enlargement, which is a normal part of ageing. Conversely, low levels of PSA in the bloodstream do not rule out the possibility of prostate cancer. However, most cases of early prostate cancer are found by a PSA blood test.

More than 35,000 new cases are diagnosed each year, making it the most common cancer among men in the UK. For reasons not fully understood, black men have the highest frequency of prostate cancer in the world and the highest death rate from the disease. Asian men are the least likely to get it.

Prostate cancer cells do not follow normal patterns. Instead, they grow uncontrollably and spread to other tissues. Prostate cancer is typically a very slow growing tumour, often causing no symptoms until advanced stages. Most men with prostate cancer die of other causes - many without ever realising that they have the disease. But once prostate cancer begins to grow more rapidly or spreads outside the prostate, it is dangerous. This aggressive type of prostate cancer can occur at any age. Although the disease tends to progress slowly, it is generally fatal if it spreads beyond the prostate gland itself.

Prostate cancer in its early stages (confined to the prostate gland) can be cured. Around 70% of newly diagnosed cases now survive beyond five years. In the 1970s, it was just 37%.

Cancer that has spread beyond the prostate to distant tissues (such as the bones, lymph nodes and lungs) is not curable, but it often can be controlled for many years. Because of the many advances in available treatments, the majority of men whose prostate cancer becomes widespread can expect to live five years or longer.