PROSTATECTOMY
Removal of the prostate by surgery
Surgery can be used to remove cancer from the
prostate and from nearby areas to which the cancer has spread. It is most
often used during the cancer's early stages (Stages Tl and T2), when
prostate cancer is located only within the prostate. Surgery may help
prevent further spread of the cancer. If the cancer is small and located
exclusively within the prostate, the surgery may cure the disease.
One surgical procedure is called perineal
prostatectomy. It involves removing the cancer through the perineum, the
area between the scrotum and the anus. The entire prostate is removed,
together with any nearby cancer.
Another procedure is called retropubic
prostatectomy. It consists of removing the cancer through the lower abdomen.
The entire prostate is removed, and if necessary, nearby pelvic lymph nodes
are removed as well.
A transurethral resection of the prostate, or
TURP, involves removing benign tissue from the prostate by inserting an
instrument through the urethra in the penis. Only part of the prostate is
removed by this technique. This is usually done to relieve symptoms and make
urinating easier. It does not cure prostate cancer.
Advantages
Prostatectomy is a one-time procedure that may cure prostate cancer in its early stages and may help extend life in the later stages. Surgery avoids the problems seen with radiation therapy. These problems are discussed in the next section.
Disadvantages
Prostatectomy is a major operation that requires hospitalization and can produce side effects, including impotence, incontinence (loss of urinary control), and narrowing of the urethra, which can make urination difficult. Impotence occurs in a high percentage of patients. In recent years, however, the percentage of men with impotence following surgery has decreased because of a new nerve sparing surgical technique. Incontinence occurs in only a small percentage of patients.
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RADIATION THERAPY
Radiation therapy uses high-energy rays to kill prostate cancer cells, shrink tumors, or prevent cancer cells from dividing and spreading. Because the rays cannot be directed perfectly, they may damage both cancer cells and healthy cells nearby. If the dose of radiation is small and spread out over time, however, the healthy cells are able to recover and survive, and the cancer cells eventually die.
Radiation therapy is usually used when prostate cancer has not spread beyond the prostate (Stages TI-T2). It can help prevent the cancer from spreading further. Like surgery, radiation therapy works best when the cancer is located in a small area. In early stages of prostate cancer, radiation therapy may cure the disease. Radiation therapy may also be used alone or in combination with hormone therapy when cancer cells have spread beyond the prostate to the pelvic area (Stages T3-T4) and for pain relief in prostate cancer that is no longer responding to hormone therapy and has spread to the bones (Stage M+).
There are numerous ways in which the high-energy rays can be delivered Three
of those are discussed below:
EXTERNAL BEAM
External beam refers to
the fact that the radiation therapy is generated and administered by a
machine outside of the patients body, as opposed to implants which either
temporarily or permanently place radioactive sources within the body. The
radiation is typically given in brief sessions, usually one session each
weekday for several weeks. External beam therapy include x-ray therapy and
Cobalt 60 gamma ray therapy.
CONFORMAL / PROTON BEAM
Conformal / Proton Beam
therapy is a form of external beam radiation treatment. Other forms of
external beam radiotherapy Conformal means that it is possible to shape the
beam in three dimensions to the shape of a tumor so that the majority of
radiation is given to the tumor and not to the surrounding normal tissue. It
is this unique ability to conform a proton beam to a specific tumor or
target which sets it apart from other forms of external beam radiotherapy.
IMPLANTS / INTERNAL BEAM / BRACHYTHERAPY (SEEDS)
In internal radiation
therapy (brachytherapy), the rays come from tiny radioactive seeds inserted
directly into the prostate. The seeds are inserted while the patient is
under anesthesia; they are too small to cause discomfort. They give off rays
continually for about a year and remain safely in place for the rest of a
person's life. Internal radiation therapy does not make the patient
radioactive.
Another form of internal radiation is delivered by injection and is used to
control bone pain in patients with metastasized (Stage M+) prostate cancer
that no longer responds to hormone therapy. Radioactive compounds have been
found that go directly to the bone and may give dramatic pain relief to many
patients with discomfort.
Advantages
Avoids major surgery. Radiation therapy may cure prostate cancer in its early stages and may help extend life in later stages. It rarely causes loss of urinary control, and it leads to impotence less frequently than does surgery. New injectable radioactive compounds, such as those containing radioactive strontium, can provide pain relief from cancer that has spread to the bone. These new compounds have fewer side effects than do the radioactive phosphorous compounds that have been available for many years.
Disadvantages
Radiation therapy can cause a variety of side effects. Most of these are minor and disappear after therapy stops. These side effects include tiredness, skin reactions in the treated areas, frequent and painful urination, upset stomach, diarrhea, and rectal irritation or bleeding. When radiation therapy is provided by an external machine, it can cause later development of impotence in some patients. Internal radiation therapy causes impotence less often, but may be associated with decreased white blood cell and platelet counts.
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Freezing of prostate cancer tissue
Targeted cryoablation of the prostate (TCAP, cryosurgery) is a minimally
invasive therapy involving ultrasound-guided placement of several probes
into the prostate. Rapid cooling at the probe tips (using Argon gas)
results in immediate cancer cell death with pinpoint accuracy. Recent
advances make it safe and effective, especially for men who don’t want or
can’t have surgery or radiation. It may also be very effective for men who
are at high risk of having small amounts of cancer just outside the prostate
or who have an aggressive tumor (Gleason grade
³
7). It is FDA-cleared and fully Medicare-approved for primary and salvage
treatment of localized prostate cancer with a 89-92% success rate in 7-8
year studies.
The
procedure is performed under either a spinal (epidural) or general
anesthesia. Under ultrasound guidance, slender probes about the size of
small knitting needles enter the prostate through tiny holes in the perineum
(the skin between the scrotum and the rectum). The probes deliver lethally
cold temperatures to cancer cells in two or more freeze-thaw cycles.
Thermocouples and a urethral warming device protect healthy tissue from
damage. The procedure usually takes an hour and a half or less. Patients go
home the day of or morning after.
Cryosurgery is most
often suggested for localized or locally advanced disease (T1-T3) or as
salvage therapy after any type of failed radiation treatment (recurrence.)
It can be combined with hormonal therapy to downsize the gland prior to
freezing. When cancer is confined to the prostate or just outside of it,
cryo has the potential to cure the disease. With promising improvements in
potency rates, cryoablation may be a desirable alternative to major surgery,
or to radiation treatments that may diminish potency over time.
Advantages
Avoids
major surgery. Less likely to cause urinary tract damage, obstructions, or
bowel difficulties than radiation. Patients often fully recover within days.
Highest negative biopsy rate at 1, 5 and 7 years of allpprostate cancer
treatments. Repeatable if necessary.
Disadvantages
Side
effects similar to surgery and radiation historically include impotence
(22-85%), incontinence (1-5%), and fistula (< 1%). Recent technology
advances and the development of nerve sparing cryo promise significant
improvements in potency results.
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HORMONE THERAPY
Hormone therapy is most commonly used to treat cancer
that has spread (metastasized) outside the pelvic area (Stages N+ and M+). Two types
of hormone therapy can be used: 1) surgical removal of the testicles, which produce
male hormones, or 2) drugs that prevent the production or block the action of
testosterone and other male hormones. Hormone therapy cannot cure prostate cancer.
Instead, it slows the cancer's growth and reduces the size of the tumor or tumors.
Hormone therapy in combination with radiation therapy or surgery
is also used in advanced stages of cancer when the disease has spread locally beyond
the prostate (Stages T3-T4). This therapy helps extend life and relieve symptoms.
When the cancer has spread beyond the prostate, complete surgical removal of the
prostate is not common. In patients with early-stage cancer (Stage T2), hormone
therapy may be used in combination with radiation therapy. A short course of hormone
therapy can also be used prior to surgery to reduce the size of the prostate and
make it easier to remove.
The primary strategy of hormone therapy is to decrease the
production of testosterone by the testicles. Regardless of the method of hormone
therapy, however, the decrease in testosterone can result in certain side effects.
These commonly include hot flashes, a loss of sexual desire, and impotence.
The specific methods used to reduce testosterone production or
block the actions of testosterone and other male hormones are described below:
Surgical removal of the testicles
An operation called orchiectomy removes the testicles, which
produce 95% of the body's testosterone.
Advantages
Orchiectomy is an effective procedure that is relatively simple
and performed only once. Often, the patient is given a local anesthetic and is allowed
to go home the same day as surgery.
Disadvantages
Orchiectomy is a surgical procedure, and many patients prefer a
nonsurgical option if it will work as well. Many men also find it difficult to accept
this type of surgery. Depending on the kind of anesthesia used, there may be special
risks in certain types of patients. Orciectomy may in some cases require hospitalization,
and it is not reversible.
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Another method, although not used much anymore, is to
administer a female hormone such as estrogen. Female hormones reduce the production
of testosterone by the testicles. The most commonly used estrogen in prostate cancer
is diethylstilbestrol, or DES.
Advantages
Estrogen therapy is simple and involves taking a pill. Unlike
orchiectomy, estrogen therapy does not involve removal of the testicles, and its
effects can be reversed.
Disadvantages
Estrogen therapy produces various side effects of its own.
Estrogens can cause water retention, embarrassing breast growth and tenderness,
and symptoms such as stomach upset, nausea, and vomiting. In addition, even low
doses of estrogen may significantly increase the risk of heart and blood vessel problems.
Another method of treatment consists of administering
a drug called a luteinizing hormone-releasing hormone analogue (or an LHRH analogue);
this leads to a drop in testosterone. Taking an LHRH analogue works just as well as
removal of the testicles but does not involve surgery. Currently available LHRH
analogues are ZOLADEX (goserelin acetate)
and Lupron (leuprolide acetate).
Advantages
Administering LHRH analogue therapy is simple; it involves an
injection every 28 days or every 12 weeks. Treatment with LHRH analogues is as
effective as orciectomy, but it does not require surgical removal of the testicles.
It also avoids the side effects of estrogen therapy.
Disadvantages
In a small percentage of patients, LHRH analogue therapy may
cause a brief rise in cancer symptoms, such as bone pain, before the testosterone
level begins to fall. This pain may be eased by the use of a pain reliever (such as
aspirin or acetaminophen) or an antiandrogen drug, which is discussed next.
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This therapy involves the use of a drug that blocks the
action of male hormones. Such a drug is called an
antiandrogen. Antiandrogen drugs are used in combination with LHRH analogue
therapy. This combination therapy is commonly known as maximal androgen blockade
(MAB) or combined androgen blockade (CAB). The currently available antiandrogens
include CASODEX (bicalutamide), Eulexin
(flutamide) and VIADUR (leuprolide acetate implant) a unique once-yearly implant.
Advantages
Ongoing clinical trials suggest that men treated with MAB
therapy live longer than men treated with LHRH analogue therapy alone. The
combined use of an LHRH analogue and an antiandrogen can also be of benefit
before or after prostate surgery or radiation therapy.
Disadvantages
Antiandrogens may cause
gynecomastia (breast enlargement), breast tenderness, hot flushes/hot flashes
and loss of libido. Other possible side effects may also include diarrhea,
nausea, vomiting, and liver injury.
CHEMOTHERAPY
Chemotherapy is the use of powerful toxic drugs to
attack cancer cells. The drugs circulate throughout the body in the bloodstream and
kill any rapidly growing cells, including healthy ones. To destroy cancer cells while
minimizing the harm to healthy ones, the drugs are carefully controlled in dosage
and frequency.
Chemotherapy is generally reserved for patients with advanced
stage cancer (Stage M+) that no longer responds to hormonal therapy. Chemotherapy
drugs do not work well in many men with prostate cancer.
There are many different chemotherapy drugs, each with its own
strengths and weaknesses. Often the drugs are used in combination with one another.
EmCyt (estramustine phosphate) is a frequently used chemotherapy drug in prostate
cancer.
Advantages
Chemotherapy drugs provide an additional means of relieving the
symptoms of advanced prostate cancer.
Disadvantages
Because the drugs circulate widely throughout the body and affect
healthy as well as cancerous cells, they produce many side effects. These include hair
loss, nausea, vomiting, diarrhea, lowered blood counts, reduced ability of the blood
to clot, and an increased risk of infection. Most of the side effects disappear when
the drugs are stopped. (Hair grows back when chemotherapy is stopped.)
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For some patients and certain stages of prostate
cancer, the recommended treatment may simply be to "watch and wait," at least
in the short term. This means that you won’t receive any immediate therapy.
Instead, your doctor will monitor the cancer by performing routine DRE and PSA
tests. Watchful waiting may be used when prostate cancer is diagnosed at a very
early stage or is not expected to progress quickly enough to begin using therapy.
Watchful waiting may also be used if a patient is not expected to tolerate other
therapy due to other adverse health conditions.
Trademarks:
Zoladex and Casodex are registered trademarks of AstraZeneca Pharmaceuticals.
Lupron is a registered trademark of TAP Pharmaceuticals.
Eulexin is a registered trademark of Schering Corporation.
Viadur is a trademark of ALZA Corporation under license to Bayer Pharmaceuticals Corporation.
EmCyt is a registered trademark of Pharmacia & Upjohn.
Sections of this site provided as an educational service by Zeneca Pharmaceuticals,
Wilmington, Delaware and are in printed form in a booklet for patients titled
PROSTATE CANCER: What it is and how it is treated. Contact your health
care provider for a copy.
Other information is from the American Cancer Society.
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