Health + Advice

Prostate Cancer and PSA screening

Prostate Cancer is a topic of concern for many men in New Zealand. It is the leading cause of cancer and the third highest cause of cancer deaths in men.

What is prostate cancer?
The prostate gland is part of the male reproductive system that sits low within the pelvis. It produces some of the fluid in semen. Usually the size of a walnut, it has the potential to grow later on in life primarily due to two reasons.

1. BPH – benign prostatic hypertrophy. This is a non-cancerous enlargement of the prostate that happens to many men as they get older. It is due to natural ageing and the effects of testosterone.
2. Prostate cancer. This is a slow growing cancer in most cases and produces similar symptoms to BPH.


Prostate cancers are generally very slow growing and tend not to be aggressive, although this is not always the case. They can further spread (metastasize) from the prostate to other parts of the body such as bones and liver in later stages of the disease.

Symptoms of prostate problems
• A weak flow when urinating
• Difficulty starting or stopping urination
• Urinating often during the day
• Waking often to urinate in the night
• Burning or stinging sensation when urinating, sometimes blood in the urine.

These symptoms occur because of the way the prostate wraps around the urethra (tube from the bladder to the outside world), so as it enlarges it compresses the bladder and urethra. They can occur no matter what the cause of the enlargement, whether cancerous or not.

What is my risk?
Prostate cancer is rare in men below the age of 50 years. Younger men have a smaller chance of having prostate cancer. However, the risk of dying from prostate cancer is higher for younger men as they have more time for the cancer to progress. Older men are more likely to die of other causes. If you have close relatives (i.e father or brother) with prostate cancer your risk is increased as below.

What tests can check for prostate cancer?
1. PSA blood test
A PSA test is a blood test to measure the level of prostate specific antigen (PSA) in your blood. PSA is made by the prostate gland and naturally leaks out into the bloodstream. PSA levels can be raised because of:
• a urinary infection
• a prostate infection (prostatitis)
• an enlarged prostate (non-cancerous benign prostatic hyperplasia)
• prostate cancer
• recent ejaculation (within the last 48 hours)
Not all men with prostate cancer have a raised PSA and not all men with a raised PSA have prostate cancer. Digital rectal examination and sometimes repeat measuring of PSA over time are used to increase the accuracy of testing.

2. Digital Rectal Examination
This is performed by a doctor, who will insert a gloved finger into the rectum (back passage) to feel the size and texture of the prostate. PSA testing and digital rectal examination are available through your local doctor (GP).

3. TRUS biopsy
A TRUS biopsy is necessary to make a diagnosis of prostate cancer and provides information about the type of cancer (if any) present. About 4 in 5 cancers will be found (1 in 5 missed) by this procedure.
In a TRUS biopsy, a needle is inserted into your prostate gland under local anaesthetic via the rectum (back passage). Very small samples of prostate tissue are taken and analysed under a microscope. This test is usually now done with the aid of a local anaesthetic and sometimes light sedation to reduce discomfort. Possible complications of TRUS biopsy are bleeding and infection.

Prostate cancer screening
Prostate cancer screening has been a controversial topic over the last few years. This is because the evidence on whether it is helpful to screen people is conflicting. Traditionally, it is recommended that digital rectal exams are used in conjunction with a PSA blood test to determine the risk of prostate cancer. However, early research showed that although these procedures increased the chances of picking up prostate cancer, it did not have any effect on decreasing death rates.

More recently, there has been convincing research from Sweden (the Gotenburg study) that has changed traditional views of prostate cancer screening. This study followed men between the ages of 50 and 64 for 14 years. A group of these men were randomly allocated to have prostate screening using PSA blood test, while the rest did not. In those who had PSA tests done, if the levels were significantly raised, they went on to have a digital rectal exam. The study found a 50% reduction in death from prostate cancer within the group of men who had PSA screening compared to those who did not.

Recommendations
Based on this new research, recommendations regarding prostate cancer screening are slowly changing.

Having regular 2 yearly PSA blood tests from age 50 onwards could increase chances of picking up prostate cancer early and treating it before it spreads. Furthermore, there may no longer be a need for a routine digital rectal exam, which can be uncomfortable and embarrassing. This may only need to be done if an elevated PSA level is detected.

Benefits and Harms of PSA testing


Having regular 2 yearly PSA blood tests from age 50 onwards could increase chances of picking up prostate cancer early and treating it before it spreads. Furthermore, there may no longer be a need for a routine digital rectal exam, which can be uncomfortable and embarrassing. This may only need to be done if an elevated PSA level is detected.

What happens after a PSA blood test?
Once a PSA test is sent off, results should be available within a week. If the test is normal, the current recommendation is to repeat the test in 2 years. If the PSA is raised, previous results are compared to see whether levels are increasing. Rising trends in test results are what indicate prostate growth, rather than actual values. In individuals with raised PSA, the doctor may repeat the test and perform a digital rectal exam to assess the size and any irregularities within the prostate.

If your PSA is raised or your prostate is not normal on examination, your doctor will discuss the options with you. It is likely that you will need to be referred to a specialist urologist for consideration of a TRUS biopsy.

Should I have a PSA test done?
The latest evidence suggests that the benefits of PSA testing probably outweigh the risks. However, having a test is not without risk and we recommend that you discuss the issue with your doctor first.

If you have any further questions, don’t hesitate to make an appointment with your doctor to discuss things further. Marc and Lois are both experienced in dealing with prostate problems and PSA testing.

Links
Benign prostate enlargement (BPH) Prostate cancer: www.patient.co.uk
Gothenburg study: www.medscape.com

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