So what is a prostate?
Many men don’t even know where their prostate is, how big it is or what its purpose is.
The prostate only appears in males. It is a gland slightly larger than a walnut, anatomically located between the bladder and the penis. Its shape is similar to that of the rounded cone and the base points toward the bladder. The prostate is just in front of the rectum. The urethra runs through the centre of the prostate, from the bladder to the penis, letting urine flow out of the body.
The prostate secretes fluid that nourishes and protects sperm. During ejaculation, the prostate squeezes this fluid into the urethra, and it’s expelled with sperm as semen.
The prostate is surrounded by connective tissue containing many muscle fibres; this capsule makes the prostate feel elastic to the touch. Scientists often split the prostate into four zones that encircle the urethra like layers of an onion.
They are listed below from outermost to innermost:
- Anterior fibromuscular zone (stroma) — made of muscular and fibrous tissue. Part of the capsule.
- Peripheral zone — mostly situated toward the back of the gland, this is where most of the glandular tissue is.
- Central zone — surrounds the ejaculatory ducts and makes up around one-quarter of the prostate's total mass.
- Transition zone — this is the smallest part of the prostate and surrounds the urethra; it is the only portion of the prostate that continues to grow throughout life.
The prostate is not vital for life, but vital for reproduction. It can be felt during a digital rectal exam. A normal prostate weighs between 20 and 30 grams, while an enlarged prostate can weigh up to 100 grams.
Diseases of the prostate
The three most common forms of prostate disease are inflammation (prostatitis), non-cancerous enlargement of the prostate (benign prostatic hyperplasia, or BPH) and prostate cancer. A man may experience one or more of these conditions.
Prostatitis
While prostatitis can affect men of any age, it is more common in younger men, aged between 30 and 50 years. The main types of prostatitis are:
- bacterial prostatitis – acute or chronic bacterial infection
- non-bacterial prostatitis – inflamed prostate, also known as chronic pelvic pain syndrome (CPPS).
In most cases, the cause of prostatitis is unknown. Bacterial prostatitis responds well to antibiotic drugs that can get into the prostate. Non-bacterial prostatitis, or CPPS, is the most common form of prostatitis and is more difficult to manage. Symptoms vary from one man to another.
There is no single test to diagnose CPPS, so your doctor will need to rule out other possible causes of your symptoms before making a diagnosis.
Possible causes of CPPS include:
- a past bacterial prostatitis infection
- irritation from some chemicals
- a problem with the nerves connecting the lower urinary tract
- problems with pelvic floor muscles
- sexual abuse
- chronic anxiety problems.
Non-cancerous enlargement of the prostate (BPH)
Non-cancerous enlargement of the prostate, or benign prostatic hyperplasia (BPH), is more common as men get older. It is not life threatening, but can significantly affect your quality of life.
The enlargement of the prostate gland (which surrounds the top of the urethra) causes the urethra to narrow, and puts pressure on the base of the bladder. This can lead to obstruction (blockage) in the flow of urine.
Obstructions usually show up as lower urinary tract symptoms that sometimes result in the urine staying in the bladder when it's supposed to be released. When this happens suddenly, it's called acute urinary retention. This is very painful and is usually relieved temporarily by inserting a thin tube (a catheter) to release the urine.
Chronic (ongoing) retention, which is less common, can lead to a dangerous, painless accumulation of urine in the bladder. An uncommon form of chronic urinary retention is associated with high bladder pressures, which can damage kidney function.
Prostate cancer
Prostate cancer typically affects men over the age of 50 years. Around 18,000 Australians are diagnosed every year. The cause remains unknown, although advancing age and family history are known to be contributing factors.
In the early stages, the cancer cells are confined to the prostate gland. With the more aggressive types of prostate cancer, cancer cells enter the vascular and lymphatic systems early and spread to other parts of the body where they develop secondary tumours, particularly in the bones.
Symptoms of prostate disease
In its earliest stages, prostate disease may or may not be associated with symptoms. The symptoms of prostate disease depend on the condition, but may include:
- difficulties urinating, such as trouble starting the flow of urine
- the urge to urinate often, particularly at night
- feeling as though the bladder can't be fully emptied
- painful urination
- blood in the urine or blood coming from the urethra independent of urination.
Blood in the urine is often due to causes not related to the prostate. Always see your doctor if you find blood in your urine.
Diagnosis of Prostate Cancer
Prostate disease is diagnosed using a variety of tests, including:
- physical examination, including digital rectal examination (DRE), where the doctor inserts a gloved finger into your rectum to check the size of your prostate
- blood test for prostate specific antigen (PSA test; discuss this with your doctor)
- mid-stream urine (MSU) tests to look for infection or blood in the urine
- ultrasound scans and urinary flow studies
- Multi-Parametric MRI scans of the prostate
- biopsies of the prostate.
Treatment of prostate disease
Treatment for prostatitis may include antibacterial drugs and supportive treatments, depending on the type of prostatitis.
Treatment for BPH may include medications to relax the smooth muscle of the gland or to shrink the size of the prostate, and surgery to produce a permanently widened channel in the part of the urethra that passes through the prostate.
Treatment for prostate cancer is tailored to suit individual circumstances. The nature of the cancer, other health problems the person may have, and their wishes will all be taken into account.
Management approaches for prostate cancer include:
- active surveillance
- surgery – for example, prostatectomy (removal of the prostate)
- radiotherapy
- ablative treatments such as high-intensity focused ultrasound (HIFU) and NanoKnife®
- hormone treatment (androgen deprivation therapy)
- chemotherapy
- watchful waiting.
Prostate cancer is the most common type of cancer in men in Australia. Usually prostate cancer grows slowly and is initially confined to the prostate gland, where it may not cause serious harm. However, while some types of prostate cancer grow slowly and may need minimal or even no treatment, other types are aggressive and can spread quickly.
Prostate cancer that's detected early, when it's still confined to the prostate gland, has a better chance of successful treatment.
