| RISING PSA
AFTER RADICAL PROSTATE SURGERY
PSA stands for Prostate Specific Antigen and is a blood test that is used
to screen for the presence of prostate cancer and, in those men known to have prostate
cancer, PSA becomes a tool to measure the effectiveness of the treatments that have been
used.
WHAT IS PSA, AND HOW DO WE MEASURE IT?
An antigen is a medical or biological term for a substance or protein that
stimulates the body to make antibodies.
Prostate Specific Antigen is a protein found in the serum that is unique or specific for
the prostate, both normal prostate and prostate cancer cells. In the case of prostate
cancer, the PSA will reflect the presence of the tumor, wherever the cancer cells are
present in the body. No other tissues or body parts can make Prostate Specific Antigen.
Therefore, the PSA levels can be measured in an individual's serum and with this
information we are able to follow prostate cancer. PSA is not harmful and a rising PSA in
the blood by itself is only a laboratory test or assay of a small amount of this unique
protein in your blood. It is the prostate cancer itself which must be treated, not the
PSA.
Prostate cancer manufactures PSA and as the prostate cancer grows, more PSA is released
into the blood stream and the PSA values rise. Conversely, if the cancer is diminishing
the PSA values fall. This fact allows us to track treatment effectiveness using PSA
levels.
WHAT IS THE SIGNIFICANCE OF THE PSA IF I HAVE PROSTATE CANCER?
When a man has had a radical prostatectomy, the entire prostate is removed.
Therefore, the PSA should be unmeasurable. Simply, when there is no prostate, there should
be no PSA. The normal PSA values for men after radical prostatectomy is less than the
lowest value that laboratories can accurately measure today (this may vary from lab to lab
from 0.02 ot 0.3). The normal values printed on laboratory sheets that say less than
4.0 are screening values for men who still have their prostate.
If a man has measurable PSA after radical prostatectomy, he has residual or recurrent
prostate cancer or, in rare cases, has a small remnant of benign prostate tissue left
behind. The PSA presence does not tell where the prostate cancer is, only that it is
somewhere. Prostate cancer may return close to the area where the prostate was removed
(local recurrence) or it may return in any body tissue away from the prostate (distant
spread), most commonly in bone, or lymph nodes not removed at the time of surgery. In men
who have measurable and rising PSA after radical prostatectomy, the PSA will continue to
rise suggesting that prostate cancer is present and growing. In most cases the rate of
rise of the PSA reflects the growth rate of the residual cancer. If a small remnant of
benign prostate tissue is left behind, the PSA will remain at very low levels, usually
less than 0.1, and will not rise.
WHEN SHOULD THE FIRST PSA BE DRAWN AFTER RADICAL PROSTATECTOMY?
While there is no set standard, we normally wait six weeks after surgery to check
the first PSA. PSA is cleared out of the blood relatively slowly and we wait this long to
make sure that we are not measuring residual PSA from the original disease and the
manipulation of the prostate and prostate cancer during the operation. We then measure the
PSA every three months for the first year, every six months the second year, and then
yearly for ten years. Each year that the PSA is unmeasurable gives a higher chance that
the next years blood draw will also be favorable. After 5-6 years of negative PSAs, it is
unlikely that the cancer will return or the PSA will ever be measurable.
What type of PSA test do I need?
Free PSA, Complex PSA (PSA-ACT), hK2 and other new PSA screening tests have no benefit
over the current used PSA tests in patients who already have a diagnosis of prostate
cancer. They are helpful only in screeing situations in helping us determine who needs or
does not need a biopsy.
WHAT TO DO WHEN THE PSA LEVEL IS FOUND TO BE MEASURABLE?
Again, whether the first PSA at six weeks, or any later PSA is MEASURABLE and
RISING makes no difference. The presence of persistant and rising PSA signals the fact
that cancer cells are present. In addition, some prostate cancers do not make PSA. These
are rare, perhaps a few percent of all prostate cancers. Recurrence of this rare situation
will be detected like other cancers, by X-ray or symptoms.
Whenever cancer is present, we try to determine the stage of the cancer. That is, where is
it? If we can localize the cancer, we have a better chance of treating it and following
its course. The tests that will be done might include a rectal examination and ultrasound
and biopsy of the area where the prostate was removed. Many prostate cancers will return
close to the prostate, in the tissues around the bladder, rectum and urethra (tube
connected to the bladder that runs through the penis). Other cancers will recur at distant
sites, particularly bone, and more particularly, the bones of the pelvis and spine. To
complete the evaluation, a bone scan, chest X-ray, CAT scan or MRI might be done depending
on how recently those tests might have been done.
WHERE MIGHT THE CANCER BE?
Historically, about 50% of cancers will return close to the prostate, the rest
will be found at distant sites. Factors that suggest distant spread rather than local
recurrence includes a higher grade cancer (Gleason score of 8-10), or involvement of lymph
nodes or the seminal vesicles. Factors that might suggest local recurrence would be clear
cut evidence that cancer had been cut across on the specimen removed. The most difficult
task is to localize the remaining cancer.
Before most radical surgeries, tests are usually done to show that no spread of the cancer
has occurred outside the prostate. Most commonly done are the bone scan and chest X-ray.
These tests are unlikely to change over the six months to a year, so that repeating them
too early may give little information.
The best chance of finding a definite site of recurrence are random biopsies of the area
around the prostates prior location. These biopsies are positive in about 20% of
patients when no nodules are present on rectal examination. If an area of suspicion can be
felt on rectal examination, the percentage rises. The area of recurrence may still be
nearby, but missed by the random biopsy needle. If these biopsies show no cancer, then the
actual site will be difficult, if not impossible to localize for some time, perhaps 1 to 3
years or longer. Repeat biopsies of the area may be indicated at a later time if there is
strong suspicion that the cancer was nearby the prostate and was not found in the first
biopsies. The length of time may depend on the growth rate of the cancer which relates to
the rate of rise of the PSA. Factors which suggest distant spread (rather than local
spread) would be: Gleason grade of 8 or greater, seminal vesicle or lymph node cancer at
surgery, and a measurable PSA within one year of surgery.
WHAT TO DO?? - THE THREE SCENARIOS
CANCER IS FOUND NEARBY THE PROSTATE AND NOWHERE ELSE
If the cancer is truly localized to the area around the prostate, then radiation
therapy can be considered to treat the remaining disease. Technically, if the radiation
treatments are successful, the cancer can still be cured. Normally this requires 5-7 weeks
of treatments, 15 minutes a day, 5 days a week. The risks include radiation damage to the
bladder and rectum and sphincter mechanism with bleeding, frequency, urgency and
incontinence of urine, stool or both. Usually these symptoms reside after treatment but a
small percentage of men will have symptoms indefinitely. On a more serious note, despite
treatment of local disease, not all cancers will be cured with post surgery radiation.
Most of the PSAs will fall, sometimes to unmeasurable levels, but a significant number
will recur despite treatment. The reasons for failure include cancers that are not
sensitive to radiation and cancers that were spread to distant sites before treatment but
could not be recognized. Is it worthwhile to treat?? We dont know for sure, but if
the cancer is felt to be localized to the area around the previous prostate location, I
feel that the benefits of possibly curing the cancer outweighs the risks of the radiation
and the chances that more distant disease is present. The chances of obtaining a good
response is related to the level of PSA at the time of treatment. Patients with a PSA less
than 2 when radiation treatments were given had longer survival than those with PSAs
greater than 2. Patients with Gleason scores more than 7, lymph node or seminal vesicle
involvment and fast rising PSAs have only a small chance of being cured by radiation
treatments.
CANCER IS FOUND AT DISTANT SITES OR BOTH DISTANT AND NEARBY
If the cancer is found elsewhere, even at only one spot, it is very likely that
more areas exist that cannot be seen. Radiation or surgery in these situations cannot be
used for cure. Sometimes a specific area will cause symptoms, or in the case of a bone,
have the risk of fracture. In these circumstances, we recommend radiation to the specific
area. If a weight bearing bone is not involved and no symptoms are present, the best
options are the use of hormone treatments or observation until symptoms or danger are
imminent.
There is no solid proof that treating early with hormones extends life expectancy, but
some evidence exists that treating early will prevent recurrence for a longer period of
time. If the side effects of hormone deprivation are unacceptable (impotency, no libido,
hot flashes), then delay in treatment may improve quality of life without shortening life
expectancy.
Another approach may be the rate of rise of the PSA. Experience suggests that the faster
rising PSAs will cause trouble sooner. A recent study from UCLA suggested that if the PSA
doubles within a year that a high probability for bone spread exists. If the
doubling time of PSA is more than one year, many patients remained without
cancer problems for 6 or 7 years. Another approach would be to look at the grade of the
original cancer. Higher grades (8,9,10) would be more likely to spread earlier and more
aggressively and therefore might benefit from early treatment with hormones.
THE AREA OF RECURRENCE CANNOT BE FOUND
This is a dilemma, particularly in men with suspicious margins suggesting that
the cancer is nearby the prostate bed. A significant proportion of these men (perhaps
~50%) treated blindly by radiation will have a reduction or disappearance of PSA for a
period of time. The response seems not to be permanent in a large percentage of men, but
still it does represent that only chance of cure if the disease is, in fact, only near the
prostate surgery and radiation sensitive. In many cases we are reluctant to recommend
radiation if the biopsies show no cancer for fear of treating an area where no cancer may
exist. Treating without a positive biopsy would create a risk for radiation complications
without any benefit. Repeat biopsies of the area may be indicated at a later time if there
is strong suspicion that the cancer was nearby the prostate and was not found in the first
biopsies. The chances of obtaining a good response is related to the level of PSA at the
time of treatment. Patients with a PSA less than 2 when radiation treatments were given
had longer survival than those with PSAs greater than 2.
As mentioned above, hormone treatment for PSA elevation without other findings is
controversial. There is some proof that treating early with hormones extends life
expectancy, and much evidence exists that treating early will prevent recurrence for a
longer period of time. If the side effects of hormone deprivation are unacceptable
(impotency, no libido, hot flashes), then delay in treatment may improve quality of life
without shortening life expectancy too much. As mentioned above, the PSA rate of rise (or
the time it takes the PSA to double in value) and the grade of the cancer should be taken
into consideration when making a decision whether or not to start treatment. Many patients
elect to delay treatment until actual evidence of spread of the cancer can be found. The
most common area of spread is to the bones and bone spread occurs rarely with the PSA
below 10. If the bone scan is positive, we usually recommend therapy with hormone
treatments or if the bone disease is limited we might suggest radiation treatment to the
areas of involvment only.
Hormone therapy should be instituted quickly for any patient with known spread of cancer
to an area which might cause a life threatening situation. Involvment of weight bearing
bones, particularly hips or spine, blockage of urinary flow or kidneys, brain or bone
marrow involvment are examples of life threatening situations.
SUMMARY
Some the these issues have not been completely described here, including the
various forms and side effects of hormone deprivation therapy. Your urologist will be
happy to go over this with you in more detail or provide further reading.
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