Written evidence from Cancer Research
UK
I have recently been contacted by one of my patients,
who has requested that I write a letter to you regarding my views
on the early detection of prostate cancer by means of measurement
of prostate specific antigen (PSA) in the blood. I should stress
that I am writing to you in my capacity as his Consultant rather
than in any of the other roles I hold.
At present in the United Kingdom around 30,000 men
each year are diagnosed with prostate cancer and every year 10,000
or so die of the disease. The reason why men die of this cancer
is that in its later and more advanced stages it spreads to other
parts of the body, particularly the bone where it can cause very
unpleasant symptoms of pain and can cause obstruction to the urinary
system and kidney failure. The options for managing this later
form of the disease are presently limited. Many men with more
advanced prostate cancer undergo hormonal treatment which involves
the reduction in the levels of the male sex hormone in the blood.
This too produces very many side effects of lack of energy, muscle
weakness and of course sexual problems. We also know now that
hormonal treatment over a long period can increase the risk of
heart disease and bone fractures. Unfortunately such treatment
of advanced cancers is usually time limited and the disease recurs
and in its later forms it is resistant to further forms of androgen
ablation therapy.
There is of course a lot of research going on to
try and find ways of treating this more advanced cancer and prolong
patients life and the UK has been very successful in this respect
with a new drug coming out of the Institute of Cancer Research
led by Dr Johan De Bono, which has improved the life expectancy
of men.
Prostate cancer in its earlier stages does not cause
any symptoms and can only be detected at present by means of a
careful examination of the prostate carried per rectum (digital
rectum examination or DRE) or by measurements of a protein which
is produced by the prostate called prostate specific antigen (PSA).
The number of men who undergo PSA testing in the United Kingdom
is incredibly low by International standards. The latest evidence
suggested about one in 12 men have undergone a PSA test and around
one in 10 to one in eight men know what a PSA test is. There is
a huge amount of ignorance and lack of information both amongst
the general public but also regrettably in primary care amongst
General Practitioners.
There are a number of problems with the PSA test.
Firstly, if a man has a level which is regarded as increased or
raised for his age that man then has to undergo a prostate biopsy
which is somewhat invasive and involves the insertion of an ultrasound
probe into the rectum and the performance of around 12 to 18 prostate
biopsies. We think that things will improve here in that better
forms of imaging or better biomarkers in the blood and urine will
enable a more accurate diagnosis to be made.
There are also problems with the PSA test itself
in that there is really no level at which a man can be guaranteed
to be free from prostate cancer. We know that men with very low
levels of the PSA can still have risks of prostate cancer.
Also regrettably the prostate biopsy itself is not
completely accurate in that some small cancers can be missed on
first biopsy and some men require second or third biopsies to
be carried out, although once again better biomarkers are available.
I enclose below some bullet points which I believe
are proven through research which I hope are helpful and I have
expanded them below at each section for your further information.
- 1. Early detection of prostate cancer
by means of PSA testing saves lives
There is no question from studies carried out in
Europe in the past few years that early detection saves lives.
There is debate about the number of lives saved for each 100 men
who undergo a PSA test but the levels would vary somewhere between
one life saved for between 15 and 40 men who are diagnosed with
prostate cancer.
- 2. Whist PSA testing saves lives it also
detects many cancers which are of low risk to the patient
Not all prostate cancers are killers. Some are very
small and are of low pathological grade (Gleason Grade of 6 or
less).
Many of these small cancers will not progress during
a man's lifetime which means that some men with these low risk
cancers can be managed expectantly by programmes known as active
surveillance or active monitoring. In other words not all screen
detected prostate cancers require surgery or radiotherapy treatment.
At present we do not have a very accurate way of identifying these
cancers but progress again is being made through research funded
by the Department of Health and the MRC and Cancer Research UK
to identify better biomarkers.
- 3. The evidence is not strong enough for
Urologists and the Government through the Department of Health
to recommend a National Programme of Screening
Because of the lack of sensitivity and specificity
of the PSA test (in other words it misses some prostate cancers
and some men with a high PSA turn out to have a benign prostate),
because of the risks and discomfort of men having to undergo invasive
prostate biopsies, because screening picks up many small cancers
that are relatively innocuous and because prostate cancer is relatively
slow growing the evidence is not good enough to recommend a National
Programme of Screening.
- 4. Men should know about the PSA test
and should be able to undergo a PSA test by their General Practitioners
The current stance of the Department of Health is
that men who request a PSA test should be given one although should
be counselled about the pros and cons as outlined in my letter
above. This was reinforced by a letter which went to all General
Practitioners from the Chief Medical Officer some years ago. Unfortunately
research carried out by Prostate Cancer Charities shows that there
is a high level of ignorance and lack of understanding both amongst
the general public and in primary care. Only about 12% to 15%
of men aged between 50 and 65 actually know what a PSA test is
and we also know from research that men who go along to their
general practitioner to request a PSA test may be turned away
by a GP who is not willing to order the test for a variety of
reasons. We think that somewhere around 15% of General Practitioners
would refuse a man a PSA test even if they requested it.
- 5. What is required to be done now
I believe now that all men aged between perhaps 40
and 65 should know what the PSA test is and should be able to
access information easily which describes the pros and cons of
PSA testing and early detection. If after due consideration they
wish to have a PSA test and wish to undergo a prostate biopsy
then they should be able to do so by the NHS. We know at present
that this is not happening. I believe that we do require a programme
of education which is targeted to General Practitioners. I believe
that all men aged between 40 and 65 should receive a leaflet outlining
the points I have raised above. There probably also needs to be
different programmes targeted at those men at increased risk.
For instance we know that men with a positive family history and
we know that men of Afro-Caribbean origins are at much increased
risk and there may be a number of initiatives which are required
to target these men perhaps drop in centres in their local communities
or a more active programme of information given at their work
place.
In other words I would conclude by saying that I
do not think the evidence is strong enough to recommend a Department
of Health led programme of screening but I do believe that the
evidence now demonstrate that early detection will save some lives
and therefore men should know about it and should be able to access
the PSA test.
The present programme put forward by the Department
of Health we know is not working and something does need to change.
20 December 2010
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