- The Prostate
- Understanding Cancer Process
- Prostate Cancer: Who's at Risk
- Detecting Prostate Cancer
- Recognizing Symptoms
- Diagnosing
- Staging
- Orthodox Treatment
- Side Effects of Treatment
The Prostate
The prostate is a gland in a man's reproductive system. It
makes and stores seminal fluid, a milky fluid that nourishes
sperm. This fluid is released to form part of semen. The prostate
is about the size of a walnut. It is located below the bladder
and in front of the rectum. It surrounds the upper part of
the urethra, the tube that empties urine from the bladder.
If the prostate grows too large, the flow of urine can be
slowed or stopped.
To work properly, the prostate needs male hormones (androgens).
Male hormones are responsible for male sex characteristics.
The main male hormone is testosterone, which is made mainly
by the testicles. Some male hormones are produced in small
amounts by the adrenal glands.
Understanding Cancer Process
Cancer is a group of many related diseases. These diseases
begin in cells, the body's basic unit of life. Cells have
many important functions throughout the body.
Normally, cells grow and divide to form new cells in an orderly
way. They perform their functions for a while, and then they
die. This process helps keep the body healthy.
Sometimes, however, cells do not die. Instead, they keep dividing
and creating new cells that the body does not need. They form
a mass of tissue, called a growth or tumor.
Tumors can be benign or malignant:
Benign tumors are not cancer. They can usually be
removed, and in most cases, they do not come back. Cells from
benign tumors do not spread to other parts of the body. Most
important, benign tumors of the prostate are not a threat
to life.
Benign prostatic hyperplasia (BPH) is the abnormal growth
of benign prostate cells. In BPH, the prostate grows larger
and presses against the urethra and bladder, interfering with
the normal flow of urine. More than half of the men in the
United States between the ages of 60 and 70 and as many as
90 percent between the ages of 70 and 90 have symptoms of
BPH. For some men, the symptoms may be severe enough to require
treatment.
Malignant tumors are cancer. Cells in these tumors
are abnormal. They divide without control or order, and they
do not die. They can invade and damage nearby tissues and
organs. Also, cancer cells can break away from a malignant
tumor and enter the bloodstream and lymphatic system. This
is how cancer spreads from the original (primary) cancer site
to form new (secondary) tumors in other organs. The spread
of cancer is called metastasis.
When prostate cancer spreads (metastasizes) outside the prostate,
cancer cells are often found in nearby lymph nodes. If the
cancer has reached these nodes, it means that cancer cells
may have spread to other parts of the body--other lymph nodes
and other organs, such as the bones, bladder, or rectum. When
cancer spreads from its original location to another part
of the body, the new tumor has the same kind of abnormal cells
and the same name as the primary tumor. For example, if prostate
cancer spreads to the bones, the cancer cells in the new tumor
are prostate cancer cells. The disease is metastatic prostate
cancer; it is not bone cancer.
Prostate Cancer: Who's at Risk
The causes of prostate cancer are not well understood. Doctors
cannot explain why one man gets prostate cancer and another
does not.
Researchers are studying factors that may increase the risk
of this disease. Studies have found that the following risk
factors are associated with prostate cancer:
- Age. In the United States, prostate cancer is found
mainly in men over age 55. The average age of patients at
the time of diagnosis is 70.
- Family history of prostate cancer. A man's risk
for developing prostate cancer is higher if his father or
brother has had the disease.
- Race. This disease is much more common in African
American men than in white men. It is less common in Asian
and American Indian men.
- Diet and dietary factors. Some evidence suggests
that a diet high in animal fat may increase the risk of
prostate cancer and a diet high in fruits and vegetables
may decrease the risk. Studies are in progress to learn
whether men can reduce their risk of prostate cancer by
taking certain dietary supplements.
Detecting Prostate Cancer
A man who has any of the risk factors described in the "Prostate
Cancer: Who's at Risk" section may want to ask a doctor
whether to begin screening for prostate cancer (even though
he does not have any symptoms), what tests to have, and how
often to have them. The doctor may suggest either of the tests
described below. These tests are used to detect prostate abnormalities,
but they cannot show whether abnormalities are cancer or another,
less serious condition. The doctor will take the results into
account in deciding whether to check the patient further for
signs of cancer. The doctor can explain more about each test.
Digital rectal examination --the doctor inserts a lubricated,
gloved finger into the rectum and feels the prostate through
the rectal wall to check for hard or lumpy areas.
Blood test for prostate-specific antigen (PSA)--a lab measures
the levels of PSA in a blood sample. The level of PSA may
rise in men who have prostate cancer, BPH, or infection in
the prostate.
Recognizing Symptoms
Early prostate cancer often does not cause symptoms. But
prostate cancer can cause any of these problems:
- A need to urinate frequently, especially at night;
- Difficulty starting urination or holding back urine;
- Inability to urinate;
- Weak or interrupted flow of urine;
- Painful or burning urination;
- Difficulty in having an erection;
- Painful ejaculation;
- Blood in urine or semen; or
- Frequent pain or stiffness in the lower back, hips, or
upper thighs.
Any of these symptoms may be caused by cancer or by other,
less serious health problems, such as BPH or an infection.
A man who has symptoms like these should see his doctor or
a urologist (a doctor who specializes in treating diseases
of the genitourinary system).
Diagnosing
If a man has symptoms or test results that suggest prostate
cancer, his doctor asks about his personal and family medical
history, performs a physical exam, and may order laboratory
tests. The exams and tests may include a digital rectal exam,
a urine test to check for blood or infection, and a blood
test to measure PSA. In some cases, the doctor also may check
the level of prostatic acid phosphatase (PAP) in the blood,
especially if the results of the PSA indicate there might
be a problem.
The doctor may order exams to learn more about the cause
of the symptoms. These may include:
- Transrectal ultrasonography --sound waves that cannot
be heard by humans (ultrasound) are sent out by a probe
inserted into the rectum. The waves bounce off the prostate,
and a computer uses the echoes to create a picture called
a sonogram.
- Intravenous pyelogram --a series of x-rays of the organs
of the urinary tract.
- Cystoscopy --a procedure in which a doctor looks into
the urethra and bladder through a thin, lighted tube.
- Biopsy --removing tissue samples from the prostate to
be checked under a microscope for cancer cells. If cancer
is present, the pathologist usually reports the grade of
the tumor.
Staging
If cancer is found in the prostate, the doctor needs to know
the stage, or extent, of the disease. Staging is a careful
attempt to find out whether the cancer has spread and, if
so, what parts of the body are affected. The doctor may use
various blood and imaging tests to learn the stage of the
disease. Treatment decisions depend on these findings.
Prostate cancer staging is a complex process. The doctor
may describe the stage using a Roman number (I-IV) or a capital
letter (A-D). These are the main features of each stage:
Stage I (A)--The cancer cannot be felt during a rectal exam.
It may be found by accident when surgery is done for another
reason, usually for BPH. There is no evidence that the cancer
has spread outside the prostate.
Stage II (B)--The tumor involves more tissue within the prostate,
it can be felt during a rectal exam, or it is found with a
biopsy that is done because of a high PSA level. There is
no evidence that the cancer has spread outside the prostate.
Stage III (C)--The cancer has spread outside the prostate
to nearby tissues.
Stage IV (D)--The cancer has spread to lymph nodes or to
other parts of the body.
Orthodox Treatment
Treatment for prostate cancer may involve watchful waiting,
surgery, radiation therapy, or hormonal therapy. Some patients
receive a combination of therapies.
Watchful waiting may be suggested for some men who
have prostate cancer that is found at an early stage and appears
to be slow growing. Also, watchful waiting may be advised
for older men or men with other serious medical problems.
For these men, the risks and possible side effects of surgery,
radiation therapy, or hormonal therapy may outweigh the possible
benefits. Men with early stage prostate cancer are taking
part in a study to determine when or whether treatment may
be necessary and effective.
Surgery is a common treatment for early stage prostate
cancer. The doctor may remove all of the prostate (a type
of surgery called radical prostatectomy) or only part of it.
In some cases, the doctor can use a new technique known as
nerve-sparing surgery. This type of surgery may save the nerves
that control erection. However, men with large tumors or tumors
that are very close to the nerves may not be able to have
this surgery.
The doctor can describe the types of surgery and can discuss
and compare their benefits and risks.
In radical retropubic prostatectomy, the doctor removes the
entire prostate and nearby lymph nodes through an incision
in the abdomen.
In radical perineal prostatectomy, the doctor removes the
entire prostate through an incision between the scrotum and
the anus. Nearby lymph nodes are sometimes removed through
a separate incision in the abdomen.
In transurethral resection of the prostate (TURP), the doctor
removes part of the prostate with an instrument that is inserted
through the urethra. The cancer is cut from the prostate by
electricity passing through a small wire loop on the end of
the instrument. This method is used mainly to remove tissue
that blocks urine flow.
If the pathologist finds cancer cells in the lymph nodes,
it is likely that the disease has spread to other parts of
the body. Sometimes, the doctor removes the lymph nodes before
doing a prostatectomy. If the prostate cancer has not spread
to the lymph nodes, the doctor then removes the prostate.
But if cancer has spread to the nodes, the doctor usually
does not remove the prostate, but may suggest other treatment.
Radiation therapy (also called radiotherapy) uses
high-energy x-rays to kill cancer cells. Like surgery, radiation
therapy is local therapy; it can affect cancer cells only
in the treated area. In early stage prostate cancer, radiation
can be used instead of surgery, or it may be used after surgery
to destroy any cancer cells that may remain in the area. In
advanced stages, it may be given to relieve pain or other
problems.
Radiation may be directed at the body by a machine (external
radiation), or it may come from tiny radioactive seeds placed
inside or near the tumor (internal or implant radiation, or
brachytherapy). Men who receive radioactive seeds alone usually
have small tumors. Some men with prostate cancer receive both
kinds of radiation therapy.
For external radiation therapy, patients go to the hospital
or clinic, usually 5 days a week for several weeks. Patients
may stay in the hospital for a short time for implant radiation.
Hormonal therapy keeps cancer cells from getting the
male hormones they need to grow. It is called systemic therapy
because it can affect cancer cells throughout the body. Systemic
therapy is used to treat cancer that has spread. Sometimes
this type of therapy is used to try to prevent the cancer
from coming back after surgery or radiation treatment.
There are several forms of hormonal therapy:
Orchiectomy is surgery to remove the testicles, which are
the main source of male hormones.
Drugs known as a luteinizing hormone-releasing hormone (LH-RH)
agonist can prevent the testicles from producing testosterone.
Examples are leuprolide, goserelin, and buserelin.
Drugs known as antiandrogens can block the action of androgens.
Two examples are flutamide and bicalutamide.
Drugs that can prevent the adrenal glands from making androgens
include ketoconazole and aminoglutethimide.
After orchiectomy or treatment with an LH-RH agonist, the
body no longer gets testosterone from the testicles. However,
the adrenal glands still produce small amounts of male hormones.
Sometimes, the patient is also given an antiandrogen, which
blocks the effect of any remaining male hormones. This combination
of treatments is known as total androgen blockade. Doctors
do not know for sure whether total androgen blockade is more
effective than orchiectomy or LH-RH agonist alone.
Prostate cancer that has spread to other parts of the body
usually can be controlled with hormonal therapy for a period
of time, often several years. Eventually, however, most prostate
cancers are able to grow with very little or no male hormones.
When this happens, hormonal therapy is no longer effective,
and the doctor may suggest other forms of treatment that are
under study.
Side Effects of Treatment
The side effects of cancer treatment depend mainly on the
type and extent of the treatment. Also, each patient reacts
differently.
Surgery
Patients are often uncomfortable for the first few days after
surgery. Their pain usually can be controlled with medicine,
and patients should discuss pain relief with the doctor or
nurse. The patient will wear a catheter (a tube inserted into
the urethra) to drain urine for 10 days to 3 weeks. The nurse
or doctor will show the man how to care for the catheter.
It is also common for patients to feel extremely tired or
weak for a while. The length of time it takes to recover from
an operation varies. Surgery to remove the prostate may cause
long-term problems, including rectal injury or urinary incontinence.
Some men may have permanent impotence. Nerve-sparing surgery
is an attempt to avoid the problem of impotence. When the
doctor can use nerve-sparing surgery and the operation is
fully successful, impotence may be only temporary. Still,
some men who have this procedure may be permanently impotent.
Men who have a prostatectomy no longer produce semen, so
they have dry orgasms. Men who wish to father children may
consider sperm banking or a sperm retrieval procedure.
Radiation Therapy
Radiation therapy may cause patients to become extremely tired,
especially in the later weeks of treatment. Resting is important,
but doctors usually encourage men to try to stay as active
as they can. Some men may have diarrhea or frequent and uncomfortable
urination.
When men with prostate cancer receive external radiation
therapy, it is common for the skin in the treated area to
become red, dry, and tender. External radiation therapy can
also cause hair loss in the treated area. The loss may be
temporary or permanent, depending on the dose of radiation.
Both types of radiation therapy may cause impotence in some
men, but internal radiation therapy is not as likely as external
radiation therapy to damage the nerves that control erection.
However, internal radiation therapy may cause temporary incontinence.
Long-term side effects from internal radiation therapy are
uncommon.
Hormonal Therapy
The side effects of hormonal therapy depend largely on the
type of treatment. Orchiectomy and LH-RH agonists often cause
side effects such as impotence, hot flashes, and loss of sexual
desire. When first taken, an LH-RH agonist may make a patient's
symptoms worse for a short time. This temporary problem is
called "flare." Gradually, however, the treatment
causes a man's testosterone level to fall. Without testosterone,
tumor growth slows down and the patient's condition improves.
(To prevent flare, the doctor may give the man an antiandrogen
for a while along with the LH-RH agonist.)
Antiandrogens can cause nausea, vomiting, diarrhea, or breast
growth or tenderness. If used a long time, ketoconazole may
cause liver problems, and aminoglutethimide can cause skin
rashes. Men who receive total androgen blockade may experience
more side effects than men who receive a single method of
hormonal therapy. Any method of hormonal therapy that lowers
androgen levels can contribute to weakening of the bones in
older men.
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