Prostate cancer is a relatively common type of cancer affecting the small walnut-shaped prostate gland located near the base of the bladder and found only in men. The gland surrounds the upper part of the urethra, the tube that leads from the bladder to the penis. In more advanced stages of the disease the tumour may spread and eventually be carried (metastasise) to other areas of the body.
Prostate cancer is the commonest cause of cancer in men in the UK, accounting for a quarter of all new cases of cancer in males. In the UK there are about 40,000 new cases of prostate cancer each year. It is rare in men under 45 and quite common in men over 80. However, in older men the cancer is often small, restricted to the prostate and without symptom.
Often, the first symptom of prostate cancer is difficulty in urination, as the growing tumour constricts the urethra. Frequent urination (especially at night); a weak or interrupted urine stream; pain or burning upon urination or ejaculation; pus or blood in urine or semen; and discomfort in the lower back, pelvis, or upper thighs, are also symptoms of the disease. Other conditions, such as urinary-tract infections, benign enlargement of the prostate (benign prostatic hypertrophy or BPH), a serious infection of the prostate gland (acute prostatitis)and sexually transmitted diseases can also cause some of these symptoms.
Doctors must determine whether a man's symptoms are due to prostate cancer, BPH, or to another non-cancer-related condition. They must also determine whether the prostate cancer they have detected is clinically significant. If a prostate cancer is small, localised, and slow-growing, it may never cause significant health problems to the individual. In these cases, the treatments may sometimes be worse than the cancer as they can cause side effects such as erectile dysfunction and incontinence.
Some prostate cancers, however, do grow and spread aggressively into the pelvic region and then throughout the body; and some slow-growing cancers are eventually large enough and troublesome enough that they require intervention. The challenge for the doctor is detecting prostate cancer, evaluating its growth rate and spread, and then deciding, along with the affected person, which treatment courses to follow and when.