What is the prostate?
The
prostate gland is a small, walnut-sized gland in men. It is located below
the bladder and surrounds the upper portion of the urethra. The prostate
gland lies in front of the rectum, and its posterior surface can be felt
during a rectal examination. The function of the prostate is to secrete
a fluid that makes up part of the semen. The prostate gland may be a source
of many health problems in men, the most common being benign prostatic hyperplasia
(BPH), prostatitis and cancer.
What is prostate cancer?
Prostate cancer is a significant health-care problem in the United States
due to its high incidence. It is the most common cancer in men affecting
approximately 189,000 American men each year with approximately 32,000 of
these men dying each year. Prostate cancer is different from most cancers
in that a large percentage of men may have a silent form of this cancer — it
does not cause symptoms or progress beyond the prostate gland. Sometimes
this cancer can be small, slow growing and present limited risk to the patient.
Clinically important prostate cancers can be defined as those that threaten
the well-being or life span of a man.
What are the causes and risks associated with prostate cancer?
What causes prostate cancer is a subject of intensive research. It is
likely that prostate cancer occurs due to many reasons. Predominately a
disease of elderly men, the diagnosis of prostate cancer is rare before
age 40 but increases dramatically thereafter. In the United States, it is
estimated that one in 55 men between the ages of 40 and 59 will develop
prostate cancer. This incidence climbs almost to one in seven for men between
ages 60 and 79. This association is also reflected in mortality as prostate
cancer accounts for 10.8 percent of cancer-related deaths in men between
the ages of 60 and 79 and 24.6 percent in those over the age of 80.
Worldwide, prostate cancer ranks third in cancer incidence and sixth in
cancer mortality among men. There is, however, a notable variability in
incidence and mortality among world regions. The incidence is low in Japan
and intermediate in regions of Central America and Western Africa. The incidence
is higher in North America and Northern Europe. Although some of these differences
may be accounted for by differences in screening for prostate cancer and
the risk of other diseases among world regions, it is likely that they can
be accounted for, in part, by genetic predisposition as well as diet.
There are also ethnic determinants of risk. Blacks are in the highest
risk group, with an incidence of 224.3 cases per 100,000 black men. The
incidence in Caucasian and Asian men is considerably lower at 150.3 and
82.2 (per 100,000), respectively. In addition, blacks tend to present with
more advanced disease and have poorer overall prognosis than Caucasian or
Asian men.
Men with a family history of prostate cancer are at an increased risk
of developing the disease. The risk correlates with the number of first-degree
relatives (father, brother or uncle) affected by prostate cancer and the
age at onset. Men with a family history of disease may have a risk of developing
prostate cancer two to 11 times greater than men without a family history
of prostate cancer.
There is also considerable evidence showing that prostate cancer is more
common in men with a high intake of fat in their diets. The worldwide difference
in prostate cancer incidence may be associated with dietary intake of soy
proteins. In Asian countries such as Japan and the Republic of Korea where
prostate cancer incidence and mortality are just a fraction of that in North
America, soy consumption in the form of tofu, soymilk and miso is up to
90 times higher than that consumed in the United States. In a study of more
than 40 nations, researchers found soy, on a per calorie basis, to be the
most protective dietary factor. This protective role may be associated with
two of soy's components, genistein and daidzein that may act as weak estrogens.
Estrogens are female hormones that inhibit prostate cancer growth. Some
experts have suggested that the worldwide differences in prostate cancer
incidence may also be explained by the high intake of green tea by residents
of Asia.
The intake of other certain dietary factors may also reduce the risk of
developing prostate cancer. Such substances include lycopene, selenium and
vitamin E. Cooked tomatoes are rich sources of the carotenoid lycopene.
Lycopenes are antioxidants that may protect cells from becoming cancerous.
Several studies have shown that the likelihood of developing prostate cancer
is reduced by high intake of lycopene. Researchers found that men ingesting
two or more servings of tomato sauce per week had a 36 percent reduction
in cancer risk compared to those who did not. Selenium intake has also been
reported to lower prostate cancer risk. In a clinical trial designed to
determine if selenium could lower skin cancer recurrences, men who took
selenium had a 63 percent reduction in prostate cancer incidence compared
to those who took a sugar pill (placebo). Attention has also focused on
vitamin D's effect on the prostate. Epidemiologic evidence shows an inverse
relationship between prostate cancer risk and ultraviolet radiation, the
primary source for vitamin D production. This observation has led some to
suggest that higher rates of prostate cancer in the elderly may be partly
due to decreased sun exposure or a decline in the body's ability to make
vitamin D with aging.
Finally, the correlation of vasectomy and prostate cancer risk remains
controversial. Although some studies have suggested that men who have undergone
a vasectomy are at an increased risk of developing prostate cancer, many
other studies have failed to show such a correlation.
What are the symptoms of prostate cancer?
In its early stages, prostate cancer often causes no symptoms. When symptoms
do occur, they may include any of the following: dull pain in the lower
pelvic area; frequent urination; problems with urination such as the inability,
pain, burning, weakened urine flow; blood in the urine or semen; painful
ejaculation; general pain in the lower back, hips or upper thighs; loss
of appetite and/or weight; and persistent bone pain.
How is prostate cancer diagnosed?
Currently, digital rectal examination (DRE) and PSA tests are used for
prostate cancer detection. The age at which time screening for prostate
cancer should begin is not known with certainty. However, most experts agree
that healthy men over the age of 50 should consider prostate cancer screening
with a DRE and PSA test. Screening should occur earlier, at age 45, in those
who are at a higher risk of prostate cancer such as black men or those with
a family history of prostate cancer.
DRE: Is performed with the man either bending over, lying on his side
or with his knees drawn up to his chest on the examining table. The physician
inserts a gloved finger into the rectum and examines the prostate gland,
noting any abnormalities in size, contour or consistency. DRE is inexpensive,
easy to perform and allows the physician to note other abnormalities such
as blood in the stool, which might allow for the early detection of rectal
or colon cancer. However, DRE is not the most effective way to catch an
early cancer so it should be combined with a PSA test.
PSA test: Is usually performed in addition to DRE and increases the likelihood
of prostate cancer detection. The test measures the level of PSA, a substance
produced only by the prostate, in the bloodstream. Very little PSA escapes
from a healthy prostate into the bloodstream, but certain prostatic conditions
can cause larger amounts of PSA to leak into the blood. One possible cause
of a high PSA level is benign (non-cancerous) enlargement of the prostate,
otherwise known as BPH. Prostate cancer is another possible cause of an
elevated PSA level. The frequency of PSA testing remains a matter of some
debate. The American Urological Association (AUA) encourages men to have
annual PSA testing starting at age 50. The AUA also recommends annual PSA
testing for men over the age of 40 who are African-American or have a family
history of the disease (for example, a father or brother who was diagnosed
with prostate cancer). Some experts have suggested that men with an initial
normal DRE and PSA level of less than 2.5 ng/ml can have PSA testing performed
every two years. Recently, several refinements have been made in the PSA
blood test in an attempt to determine more accurately who has prostate cancer
and who has false-positive PSA elevations caused by other conditions like
BPH. These refinements include PSA density, PSA velocity, PSA age-specific
reference ranges and use of total-to-free PSA ratios. Such refinements may
allow for improved increased ability to detect cancer.
Currently, it is recommended that both a DRE and PSA test be used for
the early detection of prostate cancer. It is important to realize that
in most cases an abnormality in either test is not due to cancer but to
benign conditions, the most common being BPH. For instance, it has been
shown that only 18 to 30 percent of men with serum PSA values between four
and 10 ng/ml have prostate cancer. This number rises to approximately 42
to 70 percent for those men whose PSA values exceeding 10 ng/ml.
Biopsy: Prostate biopsy is best performed under transrectal ultrasound
guidance using a spring-loaded biopsy device coupled to the transrectal
probe, which is placed in the rectum. Patients are positioned on their side
for this procedure. The physician will first image the prostate using ultrasound
noting the prostate gland's size and shape and whether or not any other
abnormalities exist, the most common of which are shadows which might signify
the presence of prostate cancer. However, not all prostate cancers are visible.
Using the spring-loaded biopsy device attached to the ultrasound probe,
the physician will perform multiple biopsies of the prostate gland. Generally,
six to 14 biopsies will be performed. Recently, many investigators have
shown that performing more than six biopsies, especially in certain regions
of the prostate gland, will improve the ability to detect prostate cancer.
Each biopsy will remove a cylinder of prostate tissue approximately 3/4
inch in length and 1/16 inch in width. The entire procedure will take 20
to 30 minutes. The biopsy tissue taken will then be examined by a pathologist
(a physician who specializes in examining human tissue to determine whether
it is normal or diseased). The pathologist will be able to confirm if cancer
is present in the biopsy tissue. If cancer is present, the pathologist will
also be able to grade the tumor. The grade indicates the tumor's "aggression
level" — how quickly it is likely to grow and spread. The most
popular prostate cancer grading system is the Gleason score system and is
designated between two and 10. Scores of two to four designate low aggressiveness,
five to six mildly aggressive, seven moderately aggressive and scores of
eight to 10 highly aggressive.
Although transrectal ultrasound guided prostate biopsy is usually very
well tolerated, approximately 20 to 25 percent of those undergoing the procedure
may find it painful. Injecting local anesthetics into the area before biopsy
may minimize this discomfort. Blood in the ejaculate (hematospermia) and
blood in the urine (hematuria) are common, occurring in approximately 40
to 50 percent of patients. High fever is rare, occurring in only 3 to 4
percent of patients. Antibiotics and enemas are usually given at the time
of the procedure to prevent infection.
Why is prostate cancer staged?
Once prostate cancer has been diagnosed by a prostate biopsy, the physician
seeks to stage the disease; that is, to determine the extent of the cancer
(i.e., the "T" stage) and whether it has spread to the lymph nodes
and/or the bones. The T stage is determined mainly by the DRE and can be
divided into the following categories:
T1: Doctor is unable to feel the tumor or see it with imaging (e.g., transrectal
ultrasound)
T1a: Cancer is found incidentally during a transurethral resection (TURP)
for benign prostatic enlargement. Cancer is present in less than 5% of the
tissue removed
T1b: Cancer is found after TURP but is present in more than 5% of the
tissue removed
T1c: Cancer is found by needle biopsy that was done because of an elevated
PSA
T2: Doctor can feel the tumor when a digital rectal exam (DRE) is performed
but the tumor still appears to be confined to the prostate
T2a: Cancer is found in one half or less of only one side (left or right)
of the prostate
T2b: Cancer is found in more than half of only one side (left or right)
of the prostate
T2c: Cancer is found in both sides of the prostate
T3: Cancer has begun to spread outside the prostate and may involve the
seminal vesicles
T3a: Cancer extends outside the prostate but not to the seminal vesicles
T3b: Cancer has spread to the seminal vesicles
T4: Cancer has spread to tissues next to the prostate (other than the
seminal vesicles), such as the sphincter, rectum and/or wall of the pelvis
To determine if the cancer has spread to the lymph nodes or bones, the
physician may order a CT scan of the pelvis or a bone scan. This is only
done when the physician deems the cancer to be very serious.
Prostate cancer represents a spectrum of disease. Although some cancers
may grow so slowly that treatment may not be needed, others can represent
a threat to life. Determining the need for treatment can be a complex decision.
Initially, the need for treatment should be based on the stage and grade
of the cancer as well as the age and health of the patient. Many physicians
have sought to devise risk assessment schemes that predict the likelihood
of disease recurrence if patients are treated and progression or significant
growth of their cancer if they undergo initial surveillance or watchful
waiting. By combining many types of information (i.e., serum PSA level and
cancer grade, stage and volume), patients can be advised of the aggressiveness
of their cancer and the need for and types of treatment available. Certain
imaging tests, such as a radionuclide bone scan, CT scan or MRI, may need
to be done to better assess whether the cancer is still confined to the
prostate or has spread elsewhere in the body. When prostate cancer spreads
(metastasizes) it is usually to the lymph nodes or bones. Not all men with
prostate cancer need to undergo imaging tests as the risk of spread to other
organs can be estimated on the basis of serum PSA levels and cancer grade.
It is reasonable to omit the bone scan in patients with newly diagnosed,
untreated prostate cancer, who have no symptoms from their cancer and have
serum PSA concentrations less than 20 ng/ml and certainly in those with
serum PSA concentrations less than15 ng/ml. Similarly, a pelvic CT scan
or MRI may not be necessary in men with lower grade cancers, cancers still
confined to the prostate and serum PSA values less than 25 ng/ml.
Frequently asked questions:
Can prostate cancer be prevented?
No. However, you can take measures to reduce the risk by maintaining your
health in general — healthy diet, being physically active and visiting
the doctor on a regular basis. Clinical studies are ongoing which are testing
the ability of some agents like vitamin E and selenium to prevent prostate
cancer.
What is the outlook for prostate cancer?
The number of men diagnosed with prostate cancer remains high. However,
survival rates are improving. It is estimated that 89 percent of men diagnosed
with the disease will survive at least five years, while 63 percent will
survive 10 years or longer.
Where can I get more information?
AUA Guidelines Patient Guides: Prostate Cancer Awareness for Men
What is radiation therapy?
Radiation therapy, also sometimes referred to as radiotherapy, is a general
term used to describe several types of treatment, including the use of high-powered
X-rays, placement of radioactive materials into the body or injection of
a radioactive substance into the bloodstream. These various types of radiation
treatments are used in a wide range of settings. These circumstances include
primary treatment of localized prostate cancer, secondary treatment for
cancer recurring within the region of the prostate and for relief of pain
and other symptoms related to prostate cancer that has spread to other parts
of the body.
What are the different types of radiation therapy?
External beam radiation therapy (EBRT): This is the most commonly used
type of radiation therapy. The emergence of EBRT as a treatment for prostate
cancer occurred in the 1950s with the development of high-powered X-ray
machines called linear accelerators. Linear accelerators produce very powerful
X-rays that penetrate deep into the body. These X-rays destroy tumor cells
by damaging their DNA. Just as with a diagnostic X-ray, there is a brief
exposure to the radiation, typically lasting several minutes. Once the treatment
is over, there is no radiation in the patient's body. The treatment is completely
non-invasive, so there is no discomfort to the patient during the delivery
of the radiation. EBRT is typically given once per day, five days per week.
Primary treatment for localized prostate cancer usually requires about eight
weeks of treatment.
Brachytherapy: Is also referred to as "seed therapy" or a "prostate
implant." Brachytherapy involves the insertion of a radioactive material,
commonly referred to as a source, into the body. Attempts to treat prostate
cancer by placing radioactive materials into the prostate date back to the
early 20th century. However, the lack of a reliable way to ensure that the
radioactive materials were placed in their desired locations limited the
use of brachytherapy to treat prostate cancer. In the 1980s, a technique
was developed using ultrasound to guide the placement of tiny radioactive "seeds" into
the prostate. This technique was first made available in the United States
in the late 1980s.
There are two approaches to brachytherapy for prostate cancer: low-dose
rate (LDR) and high-dose rate (HDR). Prostate brachytherapy is most commonly
performed using the LDR technique. With LDR brachytherapy, the seeds are
permanently placed into the prostate. The radiation is given off gradually
over a period of months. HDR brachytherapy involves the temporary placement
of a highly radioactive source into the prostate. The radiation treatment
is given off over a period of minutes and typically repeated two or three
times over the course of several days. Both LDR and HDR brachytherapy may
be combined with EBRT.
An ultrasound study may be performed prior to the day of the procedure
to ensure there are no bones interfering with the placement of needles into
the prostate. The ultrasound probe is placed into the rectum to obtain pictures
of the prostate and surrounding structures. This study is commonly referred
to as a transrectal ultrasound (TRUS). The information obtained from the
TRUS can also be used to generate a road map for seed implantation. Ultrasound
imaging is typically used to define the prostate although newer approaches
using CT scan or MRI may be used.
The LDR seed implant procedure is performed under anesthesia. Radioactive
seeds (which are smaller than a grain of rice) are loaded in individual
needles that are passed into the prostate gland through the skin between
the scrotum and anus. As the needles penetrate the prostate they are seen
on a monitor and can be accurately guided to their predetermined position.
Once the position of the needle in the prostate matches the intended position
the needle is withdrawn leaving the seeds behind in the prostate. The radioactivity
of the seeds slowly decays during the months after the operation, and there
are few long-term risks associated with this treatment.
Alternatively, HDR brachytherapy may be utilized to place a highly radioactive
source temporarily into the prostate. Hollow plastic tubes called catheters
are pre-positioned in the prostate using a technique similar to LDR brachytherapy.
The patient is then awakened and typically two or three treatments are given
over the next several days after which the catheters are removed. A remote
control device is used to move the radioactive material, which rests for
a calculated period of time at various positions within each catheter. A
computerized treatment-planning program is used to determine the required
time the radioactive material must stay at each position and the sequential
positioning of the radioactive material at each location needed to achieve
coverage of the prostate with the prescribed radiation dose.
Radionuclide therapy: Radioactive substances may also be used for treatment
of prostate cancer that has spread to the bones. These radioactive drugs,
known as radiopharmaceuticals or radionuclides, are injected intravenously
(IV). These radionuclides are absorbed by the bones. The radiation given
off is weak and does not penetrate very far into surrounding tissues and
organs. A single injection is given in the doctor's office after which the
patient may return home. Additional injections may be given after a period
of a few months once the effects of the prior injection have diminished.
What are some of the side effects of radiation therapy?
External beam radiation therapy (EBRT): The principal side effects of
EBRT are related to the treated area. Common side effects of EBRT for prostate
cancer include increased urinary frequency; mild burning with urination;
weakened urinary stream; bowel irritability including mild diarrhea, gas,
bowel urgency and tenderness; mild irritation of the skin around the rectum;
lower blood counts; and fatigue. Diet modification and medication may be
used to manage symptoms. Within one or two months following completion of
treatment, most men notice that symptoms disappear. If changes in bladder
or bowel function persist, they are typically mild. About 20 percent of
men, however, do experience more significant long-term bowel irritability.
Relatively rare complications include significant rectal bleeding, bladder
irritability and urethral stricture. The loss of sexual function is also
a relatively common side effect of radiation. However, the risk of erectile
dysfunction (ED) following radiation varies widely, depending on use of
other treatments such as hormonal therapies and the presence of other medical
conditions that may affect sexual function.
Brachytherapy: Like EBRT, urinary irritation effects are very common.
Obstructive symptoms including difficulty with urination are somewhat more
common, however, as the prostate usually swells due to the insertion of
needles into the prostate for the procedure. Approximately 5 to 15 percent
of men will experience complete urinary obstruction within several weeks
of the procedure requiring use of a catheter. Usually this problem disappears
within weeks as the swelling subsides. Since the radioactive seeds are placed
directly into the prostate, short-term bowel side effects are also relatively
uncommon. However, as the front part of the rectum lies close to the prostate,
over time bowel side effects similar to those of EBRT may occur. As with
other radiation treatments, erectile dysfunction may occur.
Radionuclide therapy: The principal side effect of radionuclide therapy
is a decrease in blood counts following treatment. Serious side effects
including infection and bleeding are fortunately rare. However, an increase
in pain may occur in the first several days or weeks after radionuclide
therapy but can be managed with increased use of pain medications until
the therapy begins to have its desired effect.
Which treatment is appropriate for each stage of prostate cancer?
In order to guide patients in choosing an appropriate treatment, doctors
depend in part on an understanding of prognostic factors that suggest how
extensive or aggressive the cancer may actually be. Such factors include
digital rectal examination (DRE), PSA test, Gleason score and biopsy. Given
the impact on prognosis that each of these factors may have, a combination
of these factors is often more useful in understanding the potential for
treatment success or failure than the use of any one factor alone. Within
the realm of clinically localized cancer, a combination of these factors
may be used to categorize patients as "low risk," "intermediate
risk" and "high risk" in terms of treatment failure. It is
important to note that while prognostic factors are helpful in guiding treatment
choices, there is no "cookbook" for selection of treatment, and
other factors including age, overall health, urinary and bowel function
and each patient's own concerns about treatment need to be taken into account.
Therefore, a thorough discussion with an individual's urologist and oncologist
is an important part of the decision-making process.
Prostate cancer that has not spread outside the immediate area around
the prostate is often referred to as clinically localized cancer. An important
distinction within the realm of clinically localized cancer is between prostate
cancers confined to the prostate, referred to as organ-confined disease,
and prostate cancer that has spread directly outside the prostate or into
the seminal vesicles. The term "clinical" is applied to the setting
where the determination that cancer has not spread to other sites, including
lymph nodes or distant tissues and organs, is based on the findings of physical
exam and diagnostic imaging tests that may include CT scan, MRI and/or bone
scan. Proof of cancer stage is only obtained by invasive procedures such
as surgical removal of the prostate or biopsy.
Treatment of low-risk clinically localized prostate cancer: The "low-risk" category
generally includes patients with T1 or T2a cancer (normal examination or
small abnormality limited to one side of the prostate), PSA less than 10
ng./ml. and/or Gleason grade less than or equal to six. These men are the
most likely to have cancer confined to the prostate. Treatment options may
include radical prostatectomy, external beam radiation therapy (EBRT), prostate
brachytherapy or in certain circumstances observation. Given that almost
all men with early detection of prostate cancer are without symptoms, the
impact that treatment may have on quality of life is an important consideration.
Treatment of intermediate-risk clinically localized prostate cancer: The "intermediate-risk" category
generally includes patients with bulky T2a disease, PSA greater than 10
ng./ml. but less than or equal to 20 ng./ml. and/or Gleason grade seven.
In addition, recent studies have suggested that the extent of tumor on biopsy,
often referred to as "percent positive biopsies" may help sort
out which men in this category have outcomes more similar to the low or
high-risk group. Men with just a little cancer found on biopsy might have
outcomes more in line with low-risk patients while men with extensive cancer
may be at greater risk for treatment failure. Overall, many men in this
category may still have cancer confined to the prostate or along the edge
of the prostate. The risk of spread outside the prostate is greater, however,
than that for men with all low-risk features.
Given the many nuances in the presentation of intermediate-risk disease
a number of treatment options may be appropriate. These options may include
radical prostatectomy, EBRT, prostate brachytherapy or a combination of
EBRT and brachytherapy. Androgen suppression therapy, commonly referred
to as hormonal therapy, may also have a role in treatment of intermediate-risk
prostate cancer when combined with radiation. While in men with high-risk
prostate cancer the role of hormonal therapy with radiation is now established,
the role in treatment of intermediate-risk prostate cancer remains to be
fully defined. The results of two large clinical studies now completed are
awaited in the next several years and hopefully will provide answers. In
the meantime, a large study of previously treated patients at the Dana-Farber
Cancer Institute did suggest a benefit to the addition of six months of
hormonal therapy to EBRT in this patient group and therefore at least warrants
consideration when radiation therapy is used.
Treatment of high-risk clinically localized prostate cancer: The "high-risk" category
includes men with any of the following features: T2c, T3 or T4 disease (abnormal
examination on both sides of the prostate or cancer that has spread outside
of the prostate as determined by digital rectal examination), PSA greater
than 20 ng./ml. and/or Gleason grade between eight and 10. Men in this category
have a substantial risk of spread of cancer outside of the prostate. Nevertheless,
some men in this category do have cancer confined to the prostate and therefore
local treatment including prostatectomy may be appropriate. In men deemed
to be at greater risk for disease spread, the most standardized radiotherapeutic
approach to treatment is the combination of EBRT and hormonal therapy. Other
treatments, including combination of EBRT and brachytherapy with or without
hormonal therapy, may be considered but the long-term results of newer approaches
remain to be fully defined. Two national studies started in the 1980s in
the United States and a third large study in Europe all showed benefit to
the use of hormonal therapy when combined with EBRT in men with various
high-risk features. The European study was the first to show an overall
survival benefit to the addition of hormonal therapy to radiation. Early
results of another study indicate a benefit to longer duration hormonal
therapy in men with high-risk prostate cancer. The use of chemotherapy in
this group of men remains to be defined and is now the focus of a few national
studies. Given the variety of presentations within the high-risk group,
the right treatment for any given individual needs to be carefully considered
in consultation with a urologist and/or oncologist.
Should radiation therapy be used as treatment following surgical removal
of the prostate (prostatectomy)?
External beam radiation therapy (EBRT) may be used following prostatectomy
when there is concern that cancer may remain in the region of the prostate.
The use of radiation in this setting to destroy residual cancer has been
sporadic for many years but only in the past five to 10 years has this approach
started to gain widespread acceptance. The possibility of success with radiation
following prostatectomy depends on the likelihood that any remaining cancer
is confined to the region of the prostate where radiation is aimed. Therefore,
the success rate varies widely depending on the presentation at the time
treatment is contemplated. Diagnostic studies may be helpful but unfortunately
no test can exclude the possibility of microscopic spread of the cancer.
The physician must therefore assess a number of factors including the pretreatment
prognostic factors, pathological findings at the time of prostatectomy and
the post-surgical PSA history in determining which patients are most likely
to have localized cancer versus cancer that has spread (metastasized).
How successful is radiation therapy in the treatment of metastatic cancer?
Radiation is often an effective treatment for preventing or managing symptoms
of prostate cancer that has spread. External beam radiation therapy is typically
very helpful in decreasing or relieving pain related to prostate cancer
that has spread to the bones. A short course of therapy usually no longer
then two weeks is sufficient in most cases. In other cases, radiation may
be used to prevent debilitating symptoms related to the uncontrolled spread
of cancer near critical organs or tissues.
How do I know if radiation therapy is the right treatment for me?
Talk to your urologist and/or oncologist. Every tumor is different, and
it is important that your doctor evaluate all aspects of your tumor (such
as localization, size, position) in order to prescribe the best treatment.
Will radiation therapy affect my sexual function?
Possibly. The risk of erectile dysfunction following radiation varies
widely, and is dependent on the use of other treatments – such as
hormonal therapy – and other medical conditions (such as diabetes
and heart disease) that may affect sexual function.
Since the doctors aren't removing my tumor, how will I know if it's gone?
Followup testing is very important in order to be sure that the tumor
has been killed. You may require regular ultrasound, a PSA test or a digital
rectal examination to be sure that the cancer has not recurred. Sometimes,
you may require additional treatment if the initial radiation does not work.
Where can I get more information?
AUA Guidelines Patient Guides: Prostate Cancer Awareness for Men
Common misspellings: prostrat
What is radiation therapy?
Radiation therapy, also sometimes referred to as radiotherapy, is a general
term used to describe several types of treatment, including the use of high-powered
X-rays, placement of radioactive materials into the body or injection of
a radioactive substance into the bloodstream. These various types of radiation
treatments are used in a wide range of settings. These circumstances include
primary treatment of localized prostate cancer, secondary treatment for
cancer recurring within the region of the prostate and for relief of pain
and other symptoms related to prostate cancer that has spread to other parts
of the body.
What are the different types of radiation therapy?
External beam radiation therapy (EBRT): This is the most commonly used
type of radiation therapy. The emergence of EBRT as a treatment for prostate
cancer occurred in the 1950s with the development of high-powered X-ray
machines called linear accelerators. Linear accelerators produce very powerful
X-rays that penetrate deep into the body. These X-rays destroy tumor cells
by damaging their DNA. Just as with a diagnostic X-ray, there is a brief
exposure to the radiation, typically lasting several minutes. Once the treatment
is over, there is no radiation in the patient's body. The treatment is completely
non-invasive, so there is no discomfort to the patient during the delivery
of the radiation. EBRT is typically given once per day, five days per week.
Primary treatment for localized prostate cancer usually requires about eight
weeks of treatment.
Brachytherapy: Is also referred to as "seed therapy" or a "prostate
implant." Brachytherapy involves the insertion of a radioactive material,
commonly referred to as a source, into the body. Attempts to treat prostate
cancer by placing radioactive materials into the prostate date back to the
early 20th century. However, the lack of a reliable way to ensure that the
radioactive materials were placed in their desired locations limited the
use of brachytherapy to treat prostate cancer. In the 1980s, a technique
was developed using ultrasound to guide the placement of tiny radioactive "seeds" into
the prostate. This technique was first made available in the United States
in the late 1980s.
There are two approaches to brachytherapy for prostate cancer: low-dose
rate (LDR) and high-dose rate (HDR). Prostate brachytherapy is most commonly
performed using the LDR technique. With LDR brachytherapy, the seeds are
permanently placed into the prostate. The radiation is given off gradually
over a period of months. HDR brachytherapy involves the temporary placement
of a highly radioactive source into the prostate. The radiation treatment
is given off over a period of minutes and typically repeated two or three
times over the course of several days. Both LDR and HDR brachytherapy may
be combined with EBRT.
An ultrasound study may be performed prior to the day of the procedure
to ensure there are no bones interfering with the placement of needles into
the prostate. The ultrasound probe is placed into the rectum to obtain pictures
of the prostate and surrounding structures. This study is commonly referred
to as a transrectal ultrasound (TRUS). The information obtained from the
TRUS can also be used to generate a road map for seed implantation. Ultrasound
imaging is typically used to define the prostate although newer approaches
using CT scan or MRI may be used.
The LDR seed implant procedure is performed under anesthesia. Radioactive
seeds (which are smaller than a grain of rice) are loaded in individual
needles that are passed into the prostate gland through the skin between
the scrotum and anus. As the needles penetrate the prostate they are seen
on a monitor and can be accurately guided to their predetermined position.
Once the position of the needle in the prostate matches the intended position
the needle is withdrawn leaving the seeds behind in the prostate. The radioactivity
of the seeds slowly decays during the months after the operation, and there
are few long-term risks associated with this treatment.
Alternatively, HDR brachytherapy may be utilized to place a highly radioactive
source temporarily into the prostate. Hollow plastic tubes called catheters
are pre-positioned in the prostate using a technique similar to LDR brachytherapy.
The patient is then awakened and typically two or three treatments are given
over the next several days after which the catheters are removed. A remote
control device is used to move the radioactive material, which rests for
a calculated period of time at various positions within each catheter. A
computerized treatment-planning program is used to determine the required
time the radioactive material must stay at each position and the sequential
positioning of the radioactive material at each location needed to achieve
coverage of the prostate with the prescribed radiation dose.
Radionuclide therapy: Radioactive substances may also be used for treatment
of prostate cancer that has spread to the bones. These radioactive drugs,
known as radiopharmaceuticals or radionuclides, are injected intravenously
(IV). These radionuclides are absorbed by the bones. The radiation given
off is weak and does not penetrate very far into surrounding tissues and
organs. A single injection is given in the doctor's office after which the
patient may return home. Additional injections may be given after a period
of a few months once the effects of the prior injection have diminished.
What are some of the side effects of radiation therapy?
External beam radiation therapy (EBRT): The principal side effects of
EBRT are related to the treated area. Common side effects of EBRT for prostate
cancer include increased urinary frequency; mild burning with urination;
weakened urinary stream; bowel irritability including mild diarrhea, gas,
bowel urgency and tenderness; mild irritation of the skin around the rectum;
lower blood counts; and fatigue. Diet modification and medication may be
used to manage symptoms. Within one or two months following completion of
treatment, most men notice that symptoms disappear. If changes in bladder
or bowel function persist, they are typically mild. About 20 percent of
men, however, do experience more significant long-term bowel irritability.
Relatively rare complications include significant rectal bleeding, bladder
irritability and urethral stricture. The loss of sexual function is also
a relatively common side effect of radiation. However, the risk of erectile
dysfunction (ED) following radiation varies widely, depending on use of
other treatments such as hormonal therapies and the presence of other medical
conditions that may affect sexual function.
Brachytherapy: Like EBRT, urinary irritation effects are very common.
Obstructive symptoms including difficulty with urination are somewhat more
common, however, as the prostate usually swells due to the insertion of
needles into the prostate for the procedure. Approximately 5 to 15 percent
of men will experience complete urinary obstruction within several weeks
of the procedure requiring use of a catheter. Usually this problem disappears
within weeks as the swelling subsides. Since the radioactive seeds are placed
directly into the prostate, short-term bowel side effects are also relatively
uncommon. However, as the front part of the rectum lies close to the prostate,
over time bowel side effects similar to those of EBRT may occur. As with
other radiation treatments, erectile dysfunction may occur.
Radionuclide therapy: The principal side effect of radionuclide therapy
is a decrease in blood counts following treatment. Serious side effects
including infection and bleeding are fortunately rare. However, an increase
in pain may occur in the first several days or weeks after radionuclide
therapy but can be managed with increased use of pain medications until
the therapy begins to have its desired effect.
Which treatment is appropriate for each stage of prostate cancer?
In order to guide patients in choosing an appropriate treatment, doctors
depend in part on an understanding of prognostic factors that suggest how
extensive or aggressive the cancer may actually be. Such factors include
digital rectal examination (DRE), PSA test, Gleason score and biopsy. Given
the impact on prognosis that each of these factors may have, a combination
of these factors is often more useful in understanding the potential for
treatment success or failure than the use of any one factor alone. Within
the realm of clinically localized cancer, a combination of these factors
may be used to categorize patients as "low risk," "intermediate
risk" and "high risk" in terms of treatment failure. It is
important to note that while prognostic factors are helpful in guiding treatment
choices, there is no "cookbook" for selection of treatment, and
other factors including age, overall health, urinary and bowel function
and each patient's own concerns about treatment need to be taken into account.
Therefore, a thorough discussion with an individual's urologist and oncologist
is an important part of the decision-making process.
Prostate cancer that has not spread outside the immediate area around
the prostate is often referred to as clinically localized cancer. An important
distinction within the realm of clinically localized cancer is between prostate
cancers confined to the prostate, referred to as organ-confined disease,
and prostate cancer that has spread directly outside the prostate or into
the seminal vesicles. The term "clinical" is applied to the setting
where the determination that cancer has not spread to other sites, including
lymph nodes or distant tissues and organs, is based on the findings of physical
exam and diagnostic imaging tests that may include CT scan, MRI and/or bone
scan. Proof of cancer stage is only obtained by invasive procedures such
as surgical removal of the prostate or biopsy.
Treatment of low-risk clinically localized prostate cancer: The "low-risk" category
generally includes patients with T1 or T2a cancer (normal examination or
small abnormality limited to one side of the prostate), PSA less than 10
ng./ml. and/or Gleason grade less than or equal to six. These men are the
most likely to have cancer confined to the prostate. Treatment options may
include radical prostatectomy, external beam radiation therapy (EBRT), prostate
brachytherapy or in certain circumstances observation. Given that almost
all men with early detection of prostate cancer are without symptoms, the
impact that treatment may have on quality of life is an important consideration.
Treatment of intermediate-risk clinically localized prostate cancer: The "intermediate-risk" category
generally includes patients with bulky T2a disease, PSA greater than 10
ng./ml. but less than or equal to 20 ng./ml. and/or Gleason grade seven.
In addition, recent studies have suggested that the extent of tumor on biopsy,
often referred to as "percent positive biopsies" may help sort
out which men in this category have outcomes more similar to the low or
high-risk group. Men with just a little cancer found on biopsy might have
outcomes more in line with low-risk patients while men with extensive cancer
may be at greater risk for treatment failure. Overall, many men in this
category may still have cancer confined to the prostate or along the edge
of the prostate. The risk of spread outside the prostate is greater, however,
than that for men with all low-risk features.
Given the many nuances in the presentation of intermediate-risk disease
a number of treatment options may be appropriate. These options may include
radical prostatectomy, EBRT, prostate brachytherapy or a combination of
EBRT and brachytherapy. Androgen suppression therapy, commonly referred
to as hormonal therapy, may also have a role in treatment of intermediate-risk
prostate cancer when combined with radiation. While in men with high-risk
prostate cancer the role of hormonal therapy with radiation is now established,
the role in treatment of intermediate-risk prostate cancer remains to be
fully defined. The results of two large clinical studies now completed are
awaited in the next several years and hopefully will provide answers. In
the meantime, a large study of previously treated patients at the Dana-Farber
Cancer Institute did suggest a benefit to the addition of six months of
hormonal therapy to EBRT in this patient group and therefore at least warrants
consideration when radiation therapy is used.
Treatment of high-risk clinically localized prostate cancer: The "high-risk" category
includes men with any of the following features: T2c, T3 or T4 disease (abnormal
examination on both sides of the prostate or cancer that has spread outside
of the prostate as determined by digital rectal examination), PSA greater
than 20 ng./ml. and/or Gleason grade between eight and 10. Men in this category
have a substantial risk of spread of cancer outside of the prostate. Nevertheless,
some men in this category do have cancer confined to the prostate and therefore
local treatment including prostatectomy may be appropriate. In men deemed
to be at greater risk for disease spread, the most standardized radiotherapeutic
approach to treatment is the combination of EBRT and hormonal therapy. Other
treatments, including combination of EBRT and brachytherapy with or without
hormonal therapy, may be considered but the long-term results of newer approaches
remain to be fully defined. Two national studies started in the 1980s in
the United States and a third large study in Europe all showed benefit to
the use of hormonal therapy when combined with EBRT in men with various
high-risk features. The European study was the first to show an overall
survival benefit to the addition of hormonal therapy to radiation. Early
results of another study indicate a benefit to longer duration hormonal
therapy in men with high-risk prostate cancer. The use of chemotherapy in
this group of men remains to be defined and is now the focus of a few national
studies. Given the variety of presentations within the high-risk group,
the right treatment for any given individual needs to be carefully considered
in consultation with a urologist and/or oncologist.
Should radiation therapy be used as treatment following surgical removal
of the prostate (prostatectomy)?
External beam radiation therapy (EBRT) may be used following prostatectomy
when there is concern that cancer may remain in the region of the prostate.
The use of radiation in this setting to destroy residual cancer has been
sporadic for many years but only in the past five to 10 years has this approach
started to gain widespread acceptance. The possibility of success with radiation
following prostatectomy depends on the likelihood that any remaining cancer
is confined to the region of the prostate where radiation is aimed. Therefore,
the success rate varies widely depending on the presentation at the time
treatment is contemplated. Diagnostic studies may be helpful but unfortunately
no test can exclude the possibility of microscopic spread of the cancer.
The physician must therefore assess a number of factors including the pretreatment
prognostic factors, pathological findings at the time of prostatectomy and
the post-surgical PSA history in determining which patients are most likely
to have localized cancer versus cancer that has spread (metastasized).
How successful is radiation therapy in the treatment of metastatic cancer?
Radiation is often an effective treatment for preventing or managing symptoms
of prostate cancer that has spread. External beam radiation therapy is typically
very helpful in decreasing or relieving pain related to prostate cancer
that has spread to the bones. A short course of therapy usually no longer
then two weeks is sufficient in most cases. In other cases, radiation may
be used to prevent debilitating symptoms related to the uncontrolled spread
of cancer near critical organs or tissues.
How do I know if radiation therapy is the right treatment for me?
Talk to your urologist and/or oncologist. Every tumor is different, and
it is important that your doctor evaluate all aspects of your tumor (such
as localization, size, position) in order to prescribe the best treatment.
Will radiation therapy affect my sexual function?
Possibly. The risk of erectile dysfunction following radiation varies
widely, and is dependent on the use of other treatments – such as
hormonal therapy – and other medical conditions (such as diabetes
and heart disease) that may affect sexual function.
Since the doctors aren't removing my tumor, how will I know if it's gone?
Followup testing is very important in order to be sure that the tumor
has been killed. You may require regular ultrasound, a PSA test or a digital
rectal examination to be sure that the cancer has not recurred. Sometimes,
you may require additional treatment if the initial radiation does not work.
Where can I get more information?
AUA Guidelines Patient Guides: Prostate Cancer Awareness for Men
Common misspellings: prostrate
Surgical Therapy Of Prostate Cancer
The prostate gland is about the size of a walnut. It is located between
the bladder and the penis, and surrounds the urethra. The prostate gland
is part of the male reproductive system. The primary function of this gland
is to make and secrete ejaculatory fluid.
What is prostate cancer?
It is a disease that affects the cells of the prostate. It occurs when
the normal process of cell growth within the prostate becomes abnormal due
to a mass of tissue called a tumor. Like many cancers, the cause of prostate
cancer is unknown. But doctors do know that it is more common in African-American
men and men with a family history of the disease. Its growth is also contributed
by the male sex hormone testosterone. Prostate cancer is very common, with
every man having a one in six chance of getting prostate cancer within their
lifetime. Now thanks to widespread knowledge about prostate check-ups, about
80 percent of the men who are found to have prostate cancer have a disease
which seems to be confined to the prostate and is therefore responsive to
treatments, including surgery.
What are the symptoms of prostate cancer?
In its early stages, prostate cancer may not cause any symptoms. But as
it progresses, the following symptoms may appear: frequent urination (especially
at night), problems with urination (inability, weakened flow, pain, burning,
etc.), painful ejaculation, blood in urine or semen and/or frequent pain
or stiffness in the back, hips or upper thighs.
How is prostate cancer diagnosed?
Ideally, prostate cancer should be detected when it is so small that there
are no symptoms. Early detection can be achieved by a digital rectal examination
(DRE) and a PSA test, which may prompt a doctor to order a prostate biopsy.
This biopsy entails the use of an ultrasonic probe that is inserted into
the rectum and a biopsy needle that is directed into various areas of the
prostate gland. Believe it or not, this procedure is relatively painless
and does not require hospitalization.
Once prostate cancer has been diagnosed by a prostate biopsy, the physician
seeks to stage the disease; that is, to determine the extent of the cancer
(i.e., the "T" stage) and whether it has spread to the lymph nodes
and/or the bones. The T stage is determined mainly by the DRE and can be
divided into the following categories:
T1: Doctor is unable to feel the tumor or see it with imaging (e.g., transrectal
ultrasound)
T1a: Cancer is found incidentally during a transurethral resection (TURP)
for benign prostatic enlargement. Cancer is present in less than 5% of the
tissue removed
T1b: Cancer is found after TURP but is present in more than 5% of the
tissue removed
T1c: Cancer is found by needle biopsy that was done because of an elevated
PSA
T2: Doctor can feel the tumor when a digital rectal exam (DRE) is performed
but the tumor still appears to be confined to the prostate
T2a: Cancer is found in one half or less of only one side (left or right)
of the prostate
T2b: Cancer is found in more than half of only one side (left or right)
of the prostate
T2c: Cancer is found in both sides of the prostate
T3: Cancer has begun to spread outside the prostate and may involve the
seminal vesicles
T3a: Cancer extends outside the prostate but not to the seminal vesicles
T3b: Cancer has spread to the seminal vesicles
T4: Cancer has spread to tissues next to the prostate (other than the
seminal vesicles), such as the sphincter, rectum and/or wall of the pelvis
To determine if the cancer has spread to the lymph nodes or bones, the
physician may order a CT scan of the pelvis or a bone scan.
In addition to staging, the physician seeks to determine the so-called "aggressiveness" of
the cancer. This is done in two ways. The first way is by determining the
grade of the cancer; that is, how "angry" it looks under the microscope.
Briefly, the most popular prostate cancer grading system is the Gleason
score system and is designated between two and 10. Scores of two to four
designate low aggressiveness, five to six as mildly aggressive, seven moderately
aggressive and eight to 10 very high aggressiveness. The second sign of
aggressiveness grading is the PSA level before biopsy. In general PSA levels
less than 10 are ideal, levels between 10 and 20 are somewhat worrisome
for more extensive disease and behavior while levels greater than 20 are
very worrisome though cure is still sometimes possible.
When is surgery the best treatment for prostate cancer?
In general, prostate cancer surgery is best performed in patients with
T1 or T2 (confined to the prostate gland) or very small T3 stage disease;
PSA levels less than 20 and a Gleason score of less than eight. In certain
circumstances, patients with more serious parameters are offered surgery
also. Finally, prostate cancer surgery is usually restricted to men who
have a 10-year or more life expectancy and are in sufficient health to withstand
the risks of major surgery.
What are some risk factors associated with prostate cancer surgery?
Risk factors for surgery are urinary incontinence and impotence. Incontinence
is rare with occurrence in less than 5 percent of all surgical cases. However,
when it does occur, there are procedures that can solve the problem. Impotence,
if experienced post-surgery, can also be treated by a variety of medications
and/or technical devices like penile prostheses.
What are the different types of prostate cancer surgery?
Retropubic prostatectomy: During this procedure, the surgeon makes an
incision through the lower abdomen. The surgeon can remove the prostate,
surrounding tissue and pelvic lymph nodes (if necessary).
Perineal prostatectomy: During this procedure, the surgeon removes the
prostate through an incision in the skin between the scrotum and the anus.
In general, the perineal surgery is a little easier on the patient, but
it may be somewhat inefficient if the cancer is serious and the lymph nodes
need to be examined before the prostate is removed.
Laparoscopic prostatectomy: This type of surgery eliminates the need for
a large surgical incision to remove the prostate. As a result, the patient
may experience less pain and scarring, faster recovery and less risk of
infection. During this procedure a telescopic instrument called a laparoscope
is inserted into the abdomen through a small incision at the belly button.
A camera attached to the laparoscope allows surgeons to view inside the
abdomen and perform the surgery without having to make a large incision.
Usually, four more small incisions are made in the abdomen to accommodate
surgical instruments and the surgery is performed. A patient is not eligible
for this type of surgery if they have had previous pelvic surgery.
What can be expected after surgical treatment?
While in the hospital, the patient begins his recovery and pain is managed
with medication. Resumption of a regular diet can usually occur by the second
day. Usually, the patient is discharged from the hospital with a catheter
in place and is taught how to manage it. The catheter is removed usually
on a return visit to the surgeon's clinic, and exercises (called Kegel exercises)
are begun by the patient to strengthen the urinary control valve. Urinary
control (continence) can be immediate or take up to six months.
Likewise, erectile potency may be immediate or may take up to one year
to return following surgery. Usually, if erections are not sufficient for
intercourse at one month, additional therapies are used until the erections
become sufficient. One does not lose the ability to have an orgasm. However
the orgasm is "dry" — very little (if any) ejaculation comes
out — so the ability to procreate is generally lost.
After the surgery, the surgeon reviews the final assessment of the removed
prostate and (if applicable) the lymph nodes. Based on this "final
pathology," a follow-up plan is developed. If the pathology is especially
serious (e.g., spread to the seminal vesicles or lymph nodes) additional
therapy may be recommended. This may include radiation therapy and/or hormone
treatment. If the pathology is not especially serious, the follow-up plan
entails regular visits to a physician and a regular PSA test. The PSA level
should be less than 0.1ng/ml. If it is greater, especially if it is greater
than 0.5 ng/ml, then cancer is still present and additional therapies are
recommended.
Frequently asked questions:
When can I resume normal activity after the surgery?
The time varies, but usually it is between three to six weeks.
Will I know if I am cured after surgery?
Not completely and it certainly varies depending on the severity of the
cancer removed. In general, one must have PSA test values of less than 0.1
ng/ml for ten years before cure is certain.
I worry about potency but I am most afraid of incontinence. What are
the odds?
That depends mostly on the surgeon and his/her experience. Usually, incontinence
is temporary and does not last long although it can persist for as much
as six to nine months. With more experienced surgeons, the risk of permanent
incontinence is 2 to 5 percent after prostate cancer surgery.
Where can I get more information?
AUA Guidelines Patient Guides: Prostate
Cancer Awareness for Men
Common misspellings: prostrate
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