Detection and Diagnosis of Prostate Cancer
Last Revised August 1, 1997
Introduction |
Indications |
How is a prostate biopsy done? |
What happens to the biopsy specimens? |
Let's look at an example
Introduction
The initial detection of signs that you may have prostate cancer is now most commonly the result of
some regular form of check-up carried out by your primary care physician which may include a digital
rectal examination (DRE) or a prostate specific antigen (PSA) test. The most common symptom which
may make a man go to either his primary care physician or a urologist, and which might subsequently
lead to a diagnosis of prostate cancer, is some form of problem with normal urination.
The diagnosis of prostate cancer requires identification by a pathologist of prostate cancer tissue in a
specimen removed from the prostate (using a technique known as a prostate biopsy). No other clinical
test can provide an absolute diagnosis of prostate cancer.
Indications for biopsy
There are four basic reasons why your urologist would recommend that you receive an initial
prostate biopsy:
- You have an elevated standard PSA level (of 4.0 ng/ml or more).
- There is a significant change in your standard PSA level over time.
- You have a standard PSA level of between 2.5 and 10.0 ng/ml and
a low free/total PSA ratio as indicated by the PSA II test.
- You have a suspicious-feeling prostate on digital rectal examination.
Expert urologists now recommend that if any one of these indicators is present, you should have
a biopsy even if your ultrasound evaluation is normal.
How is a prostate biopsy done?
Specialists in the diagnosis of prostate cancer now recommend that biopsies of the prostate be carried
out under ultrasound guidance and that several samples of tissue be taken from the prostate using an
ordered method normally called sextant biopsy.
The urologist will often ask you to have an enema prior to carrying out the biopsy, but there is no
need for anesthesia. You will almost certainly be given an antibiotic in order to prevent any possible
infection. Finally, you will likely be asked to stop taking certain drugs for one or two weeks before
the biopsy in order to minimize the risk of bleeding problems.
In carrying out the actual biopsy, using transrectal ultrasound (TRUS) to
guide the precise placement of the biopsy needle, the urologist will take six or more samples of tissue
from the prostate and then send them to the pathologist for examination. The precise number of
samples taken will depend upon what the urologist is able to see using the ultrasound machine.
Normally, he or she would expect to take six evenly spaced specimens from different areas of the
prostate (called a systematic sextant biopsy), and then additional specimens from any areas which look
suspicious according to the ultrasound. In this way the urologist will maximize the chance of finding
prostate cancer tissue if it is there in the prostate.
What happens to the biopsy specimens?
The urologist will send the biopsy specimens (often called "cores") to a pathologist for evaluation.
The pathologist will then study these specimens carefully under a microscope, and will send a report
back to the urologist which includes the following information:
- Which specimens contain prostate cancer and which do not
- The amount of prostate cancer in the specimens which do show signs of cancer
- Where in the specimen that the prostate cancer can be found
- The grade or grades of the prostate cancer in each specimen which shows signs of cancer.
This information is designed to help the urologist (and the patient) in deciding what to do next.
Readers who are interested in a more detailed understanding of the role of
the pathologist in making a diagnosis of prostate cancer may wish to
read the article by Dr Jonathan Oppenheimer entitled
"The pathologic examination of prostate tissue", which provides an
excellent introduction to this topic for the patient and explains the
importance to the patient of receiving a copy of his pathology report.
Sometimes pathology reports can be complicated and difficult to understand.
It is possible to get a "layman's translation" of your pathology report
through Pathwise, Inc. This is a commercial
service that provides detailed explanations of pathology reports for a fee. [NOTE: Pathwise appears to have closed since this was written.]
Thus, it might be better if you could simply get your doctor to explain the
pathology report to you in layman's terms. However, The Prostate Cancer
InfoLink recognizes that sometimes this may be difficult or impossible, so
the existence of the Pathwise service may
be helpful for many.
Let's look at an example
Jim Sanders is 66 years old and in good health generally. However, he goes to see his primary care
physician, Dr Rashid, because he has been having to get up a couple of times a night to go to the
bathroom. Every time he gets up in the night, he wakes his wife, Martha, who is a light sleeper. It
doesn't bother Jim that he's having to get up a couple of times a night, but it's sure bothering
Martha!
Dr Rashid asks Jim whether he has had any other problems related to urination, and how long he has
been having to get up in the night. Jim replies that occasionally he feels like his bladder isn't
emptying completely when he urinates, and that this has been going on for a couple of years now.
First he was having to get up maybe once in the night; now it's often twice.
Dr Rashid tells Jim that he wants to give him a digital rectal examination and a PSA test to see if
there are any possible problems with his prostate which could explain why he is having difficulty
controlling his need to urinate and the emptying of his bladder.
When Dr Rashid carries out the DRE, he says he thinks Jim's prostate feels normal for a man of his
age. However, the results of the PSA test show that Jim's PSA value is 5.1 ng/ml. Dr Rashid
explains to Jim that while a PSA value of 5.1 ng/ml is not necessarily unusual, he would like Jim to
see a urologist who could re-evaluate Jim and who has more experience with this type of urinary
problem than Dr Rashid has himself. Dr Rashid also tells Jim that his slight elevation in PSA level
and his problems with urination could be the result of several possible situations. Jim asks if any of
these could be serious. Dr Rashid explains carefully that the possible problems include enlargement of
the prostate (also known as benign prostatic hyperplasia) and prostate cancer. Jim is not too happy
about this, and Dr Rashid helps Jim to make an appointment with Dr Klaverman, a local urologist, as
soon as is convenient.
By the time Jim goes to see Dr Klaverman, a couple of weeks later, he is seriously concerned. He has
talked to Martha, who tells him not to count chickens before they are hatched. However, he has also
talked to his golfing buddy, Sam, whose brother died from prostate cancer two years earlier!
Dr Klaverman is patient. He asks Jim many of the same questions as were previously asked by Dr
Rashid. He explains to Jim that the first thing that he wants to do is repeat the PSA test and the DRE.
He has his office nurse take a blood sample for the PSA test before he himself carries out the DRE,
explaining to Jim that even carrying out a thorough DRE can have an effect on PSA levels. He then
carries out the DRE, and advises Jim that his prostate seems slightly enlarged, but no more than might
be expected for a man of Jim's age. He says he can feel no firmness or other distortion to the shape
of the prostate which would indicate prostate cancer, but they need to wait until they get the result of
the PSA test in a couple of days.
Two afternoons later, Dr Klaverman calls Jim at his office and tells him
that he has received his PSA
results, and they are very similar to those received when Dr Rashid first
gave Jim a PSA test -- 4.9
ng/ml. Dr Klaverman advises Jim that while he has every reason to believe
that Jim's problem is
probably benign prostatic hyperplasia, he would like Jim to have a PSA II
or free/bound PSA test. If that shows a significant risk for prostate
cancer, he will then recommend a prostate biopsy.
This example is one many men (and many wives) might recognize. Whether Jim was found to have
prostate cancer or not is less important in this fictitious example than the way in which everyone
reached the decision that he may need a prostate biopsy. And by the way, Martha's attitude was very
important in that she was right to make Jim go and see the doctor in the first place and she was also
right to tell him not to count unhatched chickens!
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