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Diagnosis and screening
for prostate disease
In some symptomless men, a diseased prostate is detected
by chance during a routine medical or attendance at a ‘well-man’
clinic. Part of this check-up may include a digital rectal
examination (DRE). To do this, the doctor feels inside the
back passage with his finger. An enlarged gland will feel
hard and possibly irregular in shape. If enlargement or roughness
is found, a test for Prostate Specific Antigen (PSA) will
be requested. This measures a protein in the blood which rises
in concentration when there are prostate problems. However,
BPH, prostate infection and cancer can all cause PSA to rise
and further tests will be necessary to find the exact reason
for any increase over normal.
Other men develop urinary symptoms and visit their GP. The
doctor will ask questions about the onset of the symptoms,
how long they have persisted, and how severe they are. He
may ask the patient to fill in an internationally agreed questionnaire
from which he can gauge the level of impact on the quality
of life and arrive at an International Prostate Symptom Score
(an IPSS). Scores from 1-6 indicate mild, 7-19 moderate and
more than 20, severe symptoms. He will also carry out a physical
examination and request a PSA test. Other tests may also be
carried out at a local hospital to measure urine flow rate
and to detect how much urine is left behind in the bladder
after urination.
In themselves, these tests will not distinguish between BPH
and prostate cancer, but will confirm that there is a problem.
To separate these two, an ultrasound scan will be carried
out. This involves the insertion of an ultrasound probe into
the back passage. The sound waves emitted provide an accurate
map of the outline of the prostate gland. Guided by the ultrasound
image, the doctor will pass a fine needle into the prostate
and remove several tiny samples of tissue for examination
(biopsies). These will be specially prepared and examined
by a pathologist under the microscope. The appearance of the
tissue is different in BPH to that in cancer, so the two conditions
can be separated.
If it appears that a tumour is present, the pathologist will
give the sample a score called a Gleason score from 1 to 5,
depending on whether or not the gland looks nearly normal
or whether the structure is very disrupted. A near-normal
appearance will be given a low score (1 or 2) and indicates
a ‘mild’, slowly-growing tumour. In the case of more advanced
cancer, the gland will have lost much of its normal appearance
and will be scored 3 to 5. To assess the severity and extent
of the cancer, about six samples of tissue are examined and
each is scored. The lowest and the highest scores are then
added together to give a rating with a maximum of 10.
If the Gleason score and the PSA results suggest that a tumour
is present, further tests will be required to decide on the
best treatment. The most likely are:
- a bone scan to find out whether there is any cancer in
the bone, and
- a magnetic resonance imaging scan (MRI) or a computed
tomography (CT) scan to give a clear picture of the extent
of the tumour in the prostate and in the organs in the lower
part of the abdomen.
Using all this information (the ‘feel’ of the gland by DRE,
the PSA test result, the Gleason score, patient history and
state of health, X-ray results, bone scans, MRI and/or CT
scans), the best approach to treatment can be determined.
For many men, this may be some form of surgery or radiotherapy.
Surgical options are important, but will not be discussed
further in this booklet, except when used in combination with
medicines. The charities and patient organisations provide
useful information on prostate surgery.
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