The early detection of Prostate Cancer in General Practice

GOT grant recipient, Dr Warren Nicholls, GP Liaison and Primary Care Advisor, MidCentral DHB

Life expectancy of New Zealanders continues to increase, and between 1985 and 2006 it rose by nearly seven years for men. One consequence of living longer is an increase in the risk of contracting cancer, particularly prostate cancer, which is the most diagnosed cancer in men in New Zealand. One in five men over 50 will develop prostate cancer.

Although most people have heard of the prostate, many have little understanding of what it does or even where it is. So first a short biology lesson. The prostate is a walnut-sized gland located beneath the bladder and wrapped around the urethra (see the diagram at the end of this article). The prostate’s function is to make a fluid that liquefies sperm as they are being ejaculated. It provides nourishment to the sperm and induces them to ‘swim’.

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There are three main problems that can affect the prostate and cause it to enlarge:

Prostatitis – Inflammation of the prostate.

Benign Prostatic Hypertrophy – A non-cancerous overgrowth of the prostate.

Prostate Cancer – While most prostate cancers are slow-growing, some are aggressive, more commonly in younger men.
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Prostatitis is treated with antibiotics and other drugs. Benign prostatic hypertrophy can be treated with drugs or with surgery (but only necessary if problems with passing urine occur). If prostate cancer is diagnosed, there are a number of treatment options including surveillance (watchful waiting), surgery, chemotherapy and radiotherapy. The earlier the diagnosis, the more likely the treatment is to be successful.

An enlarged prostate can cause symptoms such as a decreased stream of urine, feeling like your bladder never empties, dribbling before and/or after urinating and getting up during the night to pass urine. Unfortunately, there are often no symptoms with prostate cancer, which is why regular screening is essential.

All men over 50 should discuss prostrate screening options with their doctor.

Due to its location directly in front of the rectum, your doctor can feel your prostate through the rectum – a DRE or digital rectal examination. Using this technique, your doctor can determine the size and texture of the prostate. This procedure is a bit uncomfortable rather than painful. Unfortunately, only a small part of the gland can be felt and a definitive diagnosis requires a tissue sample.

The prostate produces a protein called Prostate Specific Antigen or PSA that can be measured with a blood test. Many doctors believe the PSA test can help in the differential diagnosis of prostate cancer. However, PSA can be raised in benign prostatic hypertrophy or infection, and can also be normal when cancer is present. Research is ongoing, but some of the current guidelines in New Zealand do not support the PSA test as part of a screening programme. This test is available free of charge and has received considerable media attention. Thus, there is considerable confusion, both among GPs and the public, as to what the best method of screening is.

One approach to this issue in Australia has been to develop a Patient Show Card which GPs use to demonstrate to men the various options available and assist them in making a choice about prostate cancer screening. This is known as ‘supporting patient choice’. Dr Nicholls is an advocate of introducing this system in New Zealand, but cultural and other differences between New Zealand and Australia means that changes to the programme may need to be made.
The GOT grant will allow Dr Nicholls and colleagues at MidCentral DHB to train a group of GPs to use the card, and undertake research and evaluation into the toolkit’s appropriateness and effectiveness in New Zealand, pending a wider roll out.

By Douglas Ormrod in conjunction with Dr Warren Nicholls.