PCA3: commonly asked questions
What is PCA3?
Prostate Cancer gene 3 (PCA3) is a new gene-based test carried out on a urine
sample. PCA3 is highly specific to prostate cancer and this gene is over expressed in
over 95% of prostate cancer cases. This is in contrast to PSA (prostate specific
antigen, the blood test that is most commonly used to look for evidence of prostate
cancer) which may be increased by conditions such as benign enlargement of the
prostate (BPH or BPE) or inflammation of the prostate (prostatitis). The PCA3 test
result is not affected by these conditions.
How does the test work?
Advances in medical technology have enabled scientists to detect miniscule processes
within cells, such as the way genes express their coded information.
The PCA3 test looks for the expression of genes found only in prostate cancer cells.
Up to 100 times more PCA3 is present in prostate cancer cells than non-cancerous
cells. By analyzing cells from the prostate found in the urine the likelihood of having
a prostate cancer can be determined.
What does the test involve?
Cells from the prostate are shed into the urine following a gentle examination of the
prostate, such as that is normally done by your doctor. This is called a digital rectal
examination. After this examination you will be asked to pass urine, and this will be
collected in a special container by your doctor. The cells collected are then sent off to
a PCA3 laboratory for analysis. The results take about 10 days to be returned.
Who should have the test?
If you are concerned about the possibility of prostate cancer because of an elevated
PSA or are feeling insecure about a previously performed (negative) biopsy, the
PCA3 urine test can provide additional information that may help you and your doctor
to decide whether a (further) biopsy is really needed.
As prostate cancer can also be found in patients whose PSA is normal, the PCA3 test
may help give further reassurance that you do not have a prostate cancer despite a
normal PSA level.
Can I just have a PCA3 test alone?
The PCA3 is not a “screening” test that can be performed in isolation and tell you
whether or not you do have cancer. It should be seen as just one of the possible tests
in the assessment by your urologist.
The result of the PCA3 test has to be taken into consideration along with the PSA
measurement, a digital rectal examination, and any previous history of prostate
As the PCA3 test is still a new test, we are still discovering the different ways in
which it may help us investigate men who have concerns about prostate cancer. It is
important, therefore, that we still use investigations such as PSA.
What are the possible results from this test?
Your result will come back as a test “score”. A high PCA3 Score indicates an
increased likelihood of a positive biopsy, i.e. presence of cancer cells in the prostate.
A low PCA3 Score indicates a decreased likelihood of a positive biopsy. A recent
study also suggests that the PCA3 Score can also differentiate between nonsignificant
and significant prostate cancer.
Therefore if the PCA3 score is low you may be advised that you do not need to
undergo a biopsy at this time or be reassured that there is no evidence that you have a
prostate cancer, whereas if it is high you will be advised to have a (further) biopsy.
What is the cost of the test and will my insurance reimburse it?
The cost of the test is £300, and this is payable in addition to the standard consultation
fee. If you have been referred by your doctor then the consultation fee should be
reimbursed by your insurers, and the cost of the PCA3 should be also reimbursed, but
you should check this before you attend.
Where else can I get information about this test?
Information is available at www.pca3.org. Your specialist will also discuss with you whether the test is right for you.
To contact Cambridge Urology Partnership:
The term “molecular diagnostics” is a collective name for a number of laboratory techniques that make use of nucleic acids (DNA and RNA). The introduction of these techniques has led to a true shock wave in the medical diagnostics. It is expected that these techniques will play a prominent role in medicine of the 21st century.