Prostate Cancer - How is it diagnosed?
Should I be tested for prostate cancer?
- If you have any of the risk factors of prostate cancer and are above the age of 40, we recommend that you attend to your GP to discuss screening for prostate cancer. Alternatively, you may wish to seek a specialist urological surgeon who deals primarily with prostate cancer directly.
- For patients who have symptoms, we suggest screening for prostate cancer from the age of 50.
- For men in the general population, prostate cancer screening, using both PSA testing and a DRE, should begin at age 50 following discussion with their GP or a specialist.
How do I test for prostate cancer?
The diagnosis of prostate cancer begins with a digital rectal examination (DRE) and a PSA blood test. Both an elevated PSA level and/or an abnormal DRE are possible indicators of the disease of prostate cancer. However, neither test, alone or in combination can provide a definitive diagnosis of prostate cancer. (Men who have a common, non-cancerous condition called benign prostatic hyperplasia (BPH) may also have elevated PSA levels. It is therefore best to take advice from a specialist with regards to the significance of your results. Your specialist may recommend and perform a biopsy of your prostate to confirm the diagnosis of prostate cancer. This is called a trans-rectal ultrasound guided biopsy (TRUSS biopsy).
What is PSA?
However, any process which results in increased activity of cells such as infection, BPH and inflammation, may result in PSA being raised beyond its normal limits. The prostate increases in size with age due to BPH and naturally, the bigger the prostate, the larger the number of cells and hence the higher the PSA levels.
To balance the influence of age on PSA levels, the following age-specific PSA level cut-offs should be considered:
- < 2.5 ng/mL for men up to age 49
- < 3.5 ng/mL for men aged 50 to 59
- < 4.0 ng/mL for men aged 60 – 70
- <6 ng/ml for men aged above 70
Men with values outside their age-allowed targets may be recommended to have a prostate biopsy. These ranges are only guides, however. Whilst the higher the PSA, the more likely that cancer is present, We have seen patients with PSAs in the hundreds, which have been caused by infection and not cancer. Therefore, if you do have an elevated PSA level, you should discuss its implications with your specialist before deciding on further investigation.
What happens if I have an elevated/abnormal PSA?
If there are no other symptoms or signs of prostate cancer, you may simply wish to repeat the PSA level over a period of time to see if it changes. Your doctor should also check a urine sample to exclude infection. If there is any clinical suspicion of prostate cancer or if you and your doctor are worried about the elevated PSA in the absence of any symptoms or signs, you will be referred for a Transrectal Ultrasound Scan and Biopsy (link to TRUS).
What is a DRE?
A digital rectal examination (DRE) is a short physical examination (<30 seconds) whereby a doctor inserts a gloved finger into the rectum to feel for lumps in the prostate. A prostate that feels abnormal should be considered for TRUSS biopsy to exclude prostate cancer regardless of the level of your PSA.
What is a Prostate Biopsy?
A TRUS guided prostate biopsy will usually be recommended for the following reasons;
- You have a higher than normal PSA level for your age,
- Your consultant has detected an abnormal feeling prostate on rectal examination.
Before undertaking a TRUS biopsy, we will talk to you at length about the advantages and disadvantages of undergoing the procedure, and the implications of a positive result.
Your biopsy will be performed by either Mr Cole or Mr Hamid. We have each performed over 1000 biopsies.
The procedure is performed under local anaesthetic and is generally well tolerated by men. A small ultrasound probe is inserted a short distance into back passage and enables your specialist to biopsy specific areas of the prostate within it. We then take a number of biopsies using a tiny needle which are sent immediately to the pathology laboratory for analysis. The whole procedure should take no more than fifteen minutes, and you will be able to go home or return to work soon afterwards.
A TRUS guided biopsy is a safe procedure. However, as with all invasive procedures there are some possible side-effects;
- You may see blood in your urine or motion for up to 2 weeks, and in your semen for up to 6 weeks. If you are on tablets to thin your blood (for example - warfarin or clopidogrel), it is important that you mention this to your doctor before the procedure is performed.
- About 1 out of 100 men will suffer from a blood infection, which may require hospital admission and antibiotics. You will be given some antibiotics at the time of the procedure, and to take home, to reduce the risk of this.
The analysis of the prostate biopsies usually takes about 10 days, and we will therefore make you an appropriate follow-up appointment to discuss the result.
What if the biopsy shows no prostate cancer?
The TRUSS biopsy is the only test that can confirm prostate cancer and is quite accurate in a majority of cases. Unfortunately, a negative biopsy does not give a guarantee that no cancer is present due to sampling error. Therefore, although a negative result is very reassuring, your urologist advise to follow you up with a repeat PSA and perhaps PCA3 test after 6-12 months. Depending on these results, further prostate biopsy might be necessary.
PCA3 test - what is it?
PCA3 is a new gene-based urine test for prostate cancer. It measures substances in the urine produced by prostate cancer cells. It is a simple test to perform which involves a brief DRE followed by a collection of urine.
It has some advantages over the standard PSA test:
- It can avoid unnecessary prostate biopsies in patients who may have a raised PSA due to non-cancerous processes (i.e. it is more specific than PSA). This is because it is only produced by prostate cancer cells and not by increased prostate size.
- It can provide extra reassurance that if you have had a negative prostate biopsy, prostate cancer has not been missed by the biopsy
