The PSA test is a commonly performed blood test. Prostate specific antigen is a protein
made purely by the prostate gland for reproductive purposes and leaks into the bloodstream by
accident. It does however get into the bloodstream in higher quantities when the vascular supply
of the prostate gland is abnormal such as when it is infected or inflamed or in prostate
cancer. However, it can also leak into the bloodstream in higher quantities when the
prostate is simply enlarged in a benign fashion which is common as men get older and also
it can go up slightly when there has been recent sexual activity or strenuous cycling.
It's important to do the PSA test when middle-aged or elderly men come to the doctor complaining
of symptoms of urinary bladder voiding or if prostate cancer is suspected. There isn't
a screening programme for prostate cancer, so PSA won't be done automatically by most
doctors and it's very important to rule out urinary infection before the PSA test is taken.
No, the PSA test is not entirely reliable. In fact, about 10% of cancers can be found
in men with a normal PSA test and up to three-quarters of men who have an abnormal test do not have
cancer.
When a patient comes to see me who has an abnormal PSA according to his age, I want
to perform an examination called a digital rectal examination which enables me to feel
the back surface of the prostate just inside the rectum. It is a bit uncomfortable and
takes about 30 seconds to do. I will be wanting to see if the prostate gland feels very large,
whether it is tender to suggest inflammation, or whether it might contain hard areas or
nodules. After that, and assuming there is no urinary infection, I will probably recommend
a dedicated prostate MRI scan and then will consider a prostate biopsy once the scan has
been done.
A prostate biopsy is a procedure where we take small snippets of prostate tissue to
send to a pathologist in the laboratory to look at down the microscope to decide whether
or not cancer is present. The procedure is usually done under local anaesthetic, takes
about five minutes and it is a bit uncomfortable. Most people find this because an ultrasound
device, it has to be put into the back passage to image the prostate during the collection
of the biopsy samples. We need to give antibiotics to guard against infection and we usually
want to stop anticoagulants to make sure there isn't any excessive bleeding as a result of
the biopsies. The result of the biopsy usually takes one to two weeks to come back and it
will tell us whether or not there is cancer in the samples and it will tell us how much
cancer and the grading or aggressiveness of the disease. Something we use commonly as
a Gleason score.
Well, we don't use x-rays much in the detection of prostate cancer, but a dedicated prostate
MRI scan is extremely useful in pinpointing regions of interest within the prostate and
outside the prostate that may be relevant. If we see something in the prostate on an
MRI scan that looks suspicious, it can be targeted with a biopsy. Not all suspicious
areas turn out to be cancer and in about one in six cases, there can be significant cancer
found even when the MRI appears to be normal. So, some patients will choose to have an MRI
scan followed by a biopsy regardless of whether the MRI pinpoints an abnormality or not, whereas
others will take the chance and avoid a biopsy if the MRI looks normal.
Following a diagnosis of prostate cancer by biopsy, then it's important to decide whether
or not treatment is necessary. And I say this because some very small, non-aggressive prostate
cancers grow extremely slowly and there is no threat from them during the following 10
or 20 years. So we manage these with what we call active surveillance: PSA testing,
occasional repeat MRIs and biopsies, and the beauty of this is that it avoids the side
effects of treatment for a lot of men. However, if the disease has a slightly bulkier or higher
grade or aggressiveness to it, then curative treatment would be necessary should it be
within the prostate gland, and we can offer surgical removal of the prostate which is
called a radical prostatectomy or radiotherapy delivered with either external beam or implant
of brachytherapy seeds. However, if it has spread away from the prostate: gone to bones,
lymphatic glands, liver, lungs which is uncommon, but then we can't treat it with surgery or
radiotherapy. We have to offer drug treatments with chemotherapy, hormonal therapy to suppress it.