Prostate
Cancer
What and where is the Prostate ?
The prostate is a gland about the size of a plum, it sits just below the bladder and
just in front of the rectum. The uretha which carries the urine from the bladder to
the penis goes through the middle of the prostate. It is thus difficult to get at for
any treatment without damaging the other organs.
By courtesy of the Covent Garden Cancer Research Trust (Illustration by Diane Mercer).
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What is its Function ?
The function of the Prostate is to make the seminal fluid which carries the sperm into the uretha. The sperm is made in the testes and travels up to the Prostate.
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What can go wrong with it ?
With age the Prostate enlarges, when this happens it can strangle the uretha and thus
impede the flow of urine. This enlargement can be caused by a non cancerous swelling
known as ' Benign Prostatic Hyperplasia ' (BPH) In which case if it becomes a
problem it can be treated by an operation known as ' Trans Urethal Resection of the
Prostate ' (TURP)
However the enlargement can be caused by a cancer growth, this may or may not restrict
the flow of urine. This cancer growth is very common in older men, in fact 40% of men
over 70 will have prostate cancer. Usually prostate cancer is very slow growing and
so it is claimed that more men die with prostate cancer than from it.
In some cases, particularly in younger men prostate cancer will be much more
aggressive and will need active treatment. Doctors measure the aggressiveness of
prostate cancer on a scale called the Gleason score. This is worked out from samples
extracted in a biopsy and is measured as follows :
Least aggressive Score 2 - 4
Moderately aggressive Score 5 - 7
Most aggressive Score 8 - 10
Doctors describe how aggressive a cancer is either according to a Grade (G) or a Gleason Score (GL).
By courtesy of the Covent Garden Cancer Research Trust (illustrations by Diane
Mercer).
Note: Since this guidance was first published, there has
been a change in the assignment of Gleason scores:
Least aggressive
is now scored as 6 or less
Moderately aggessive is scored as
7
Most aggressive is scored as 8 or more
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Who can get Prostate Cancer ?
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What causes it ?
The cause of Prostate Cancer is unknown, it is not currently linked to diet or
pollutants although these are possible causes.
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What are the Symptoms ?
Unfortunately symptoms in the early stages as with so many cancers are few, there will
be some swelling of the prostate but because of its location this is not visible. It
is likely that there will be some problem with passing water, this is most likely to
mean frequent visits to the toilet, getting up in the middle of the night, thinking
one needs to go to the toilet only to find out there is little water to pass.
However these are all the same symptoms one has with non cancerous prostate problems
which are more common.
Because there are no positive symptoms most cancer patients particularly in younger
men are not diagnosed until the problem is advanced. However treatment to slow down
the cancer growth is still possible even in quite advanced cases.
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How is Diagnosis made ?
There are 3 stages in the diagnosis: Digital Rectal Examination, PSA blood test, and Biopsy.
Digital Rectal Examination (DRE)
It is possible for a doctor to feel the Prostate from the rectum. He will feel for
hard lumps and other irregularities.
By courtesy of the Covent Garden Cancer Research Trust (illustrations by Diane
Mercer).
Prostate Specific Antigen test ( PSA )
A blood test can measure the level of PSA in the blood, which can give an indication
of the prescience of prostate cancer. The PSA is measured in terms of milligrams per
litre, under 4 is said to be normal, with over that figure there is an increasing risk
of the existence of prostate cancer. Unfortunately the test is not conclusive, other
factors can cause a high PSA so that a high reading may not indicate cancer. It is
also possible that one may have cancer but not have a high PSA.
At the present time in the UK there is no national screening using PSA testing
although this is in use in other countries.
Trans-rectal ultrasound and biopsy
(TRUS)
The ultrasound can produce an image of the Prostate on a screen for a specialist to
examine. At the same time minute samples from the organ can be removed for
examination in the Pathology laboratory which should give a better picture of the
situation, it should be possible to determine at this point how aggressive the cancer
is. For this purpose the Gleason Score was invented, (see section 3 above )
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8. What happens next ?
If a positive diagnosis for Prostate Cancer is made by the specialist he will invite the patient to a consultation, he will explain his findings and discuss the possible treatments advisable in the situation. This is a qualitative judgement but there may be a choice available in which case he will discuss this with the patient. (see treatments).
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