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The following information is
provided for a better understanding of the disease
and does not replace the dialogue men should have
with their physician regarding screening and treatment
for prostate cancer.
In The News
A complex and usually slow growing
cancer, prostate cancer is the most common non-skin
cancer and the second leading cause of cancer death
in the US today. However, because of potential harms
in treatment of prostate cancer that would never have
developed symptoms related to cancer in their lifetime,
screening guidelines for men have changed. One physician
writing for the American Cancer Society writes” …the
sad reality that there is much we don’t know
about the diagnosis and treatment of this very common
cancer.” We do know that most prostate cancers
grow very slowly, and because of this other medical
illness will cause the affected man’s death.
Adding to the confusion, there are some prostate cancers
that are more aggressive. Because of these factors
the following guidelines are now recommended:
Most physicians
offer prostate screening to men aged 50. Physicians
should still make the same recommendation to their
patients as they have for several years: be informed
and make a choice on what you want to do. For African-American
men, who are at a higher risk of death from prostate
cancer than white men, the American Cancer Society
recommends the test should be done beginning at age
45. That is not the same as offering the
test. The same is true for any man with a first degree
relative who has had prostate cancer. And for men with
more than one first degree relative with prostate cancer,
they can consider testing beginning at age 40.
The Annals
of Internal Medicine, established by the American College
of Physicians is now recommending men 75 and older
not be screened for prostate cancer as “there
is moderate certainty that the harms of screening for
prostate cancer outweigh the benefits.”*
In other
news, early clinical trials continue for an experimental
drug abiraterone on tumors in men who haven’t
responded to other therapies. More research is underway
and it will be some time before the results are completely
known.
* Source: http://www.annals.org/cgi/content/full/149/3/185
About the prostate gland
A small gland the size of a walnut, the prostate is
exclusive to men. Located underneath the bladder and
in front of the rectum the prostate is part of the
body’s semen making process. It’s triggered
by testosterone, a male hormone, which can influence
the behavior of the prostate gland and prostate cancer.
Nerves to the penis important in producing and maintaining
an erection run very close to the prostate. And the
urethra runs through the prostate. If the prostate
enlarges, it can block the flow of urine from the bladder
making it difficult for a man to urinate.
About prostate
cancer
There are different types of tumors and not all are
cancerous. Those that cannot spread or threaten a life
are benign. Those that invade surrounding tissue and
even spread throughout the body are malignant tumors.
Most prostate cancer is very slow growing and will
never endanger or affect quality of life. However,
sometimes these cells grow quickly, spread to nearby
tissue and lymph nodes. If prostate cancer has spread
to the patient’s lymph nodes when it is diagnosed,
it means that there is higher chance that it has spread
to other areas of the body.
Risk factors
Researchers at University of Pennsylvania’s
Abramson Cancer Center believe every man over the age
of 45 is at risk for prostate cancer. The American
Cancer Society recommends screening of men 50 and older.
Age is most often a factor as 70% of men diagnosed
with prostate cancer are over the age of 65. It is
2nd in occurrence to skin cancer in the US. One man
in six will develop prostate cancer and one in 35 will
die from it. In between are men whose quality of life
will be changed by it.
Risk factors include age, age
as incidence of prostate cancer rises quickly after
the age of 60, and the majority of men will have some
form of prostate cancer after the age of 80. It is
said that that older men (over the age of 80) die with
prostate cancer not from prostate cancer. It means
that many men have developed the slow growing microscopic
form of prostate cancer but is not life threatening.
The controversy about this difficult form of cancer
is that the rarer form can grow quickly even in older
patients. Current screening is not perfect in discerning
which type of cancer is developing.
Another risk factor
is ethnicity. Men of African-American decent and of
Latin descent tend to have a higher risk of developing
prostate cancer. Men of Asian or Native American descent
have a lower risk. Caucasian men fall in the middle.
This risk factor is not well understood. While genetics
may be a factor, there is some evidence that diet may
be a factor. Some studies indicate that a diet high
in animal fat may raise a man’s risk
of developing prostate cancer. Conversely a diet low
in vegetables may also raise risk.
Family history is the third risk factor known today.
A father or brother with prostate cancer increases
a man’s risk of developing prostate cancer. With
a family history of prostate cancer developed at a
younger age the risk increases even more. Certain mutations
in genes may have an increase in prostate cancer risk
as well as men with high levels of testosterone.
Prevention
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Because so many men will develop prostate cancer there
is a lot of interest in trying to prevent it with drug
therapy, and the consumption of certain foods or nutrients.
Little is known about this complex disease and much
research is underway. At this time prevention includes
the patient taking control over his own health. That
includes a low fat diet that is rich in fruits and
vegetables. Although certain foods and nutrients are
being researched more data is needed. Currently, there
are studies looking at selenium, lycopene, vitamin
A and other retinoids, vitamin D, vitamin E, and soy
for prostate cancer prevention.
Drugs like Flutamide
and Finasteride can decrease the levels of testosterone
in the prostate to attempt to stop prostate cancer
from forming and growing. They are currently under
investigation for prostate cancer prevention. Drugs
that decrease total body testosterone have many undesirable
side effects and are not considered a good choice for
prostate cancer prevention.
Screening
Screening for prostate cancer is a highly controversial
issue. There is no good data showing that screening
for prostate cancer reduces deaths from prostate cancer.
There are currently very large trials on-going to see
which populations of men will benefit most.
The American
Cancer Society, the American Urological Society, and
many medical communities recommend screening annually
for men 50 and over. Two methods are used: a digital
rectal exam (DRE) and a prostate specific antigen (PSA)
blood test. The digital rectal exam is done in the
primary care physician's office. Because the prostate
is so close to the rectum, a doctor can feel it by
inserting a gloved, lubricated finger into the anus.
Lumps, asymmetries, or an enlarged prostate can be
detected this way though some small cancers can be
missed. A PSA looks for a protein that the prostate
makes. Normal prostate tissue makes a little bit of
PSA, but prostate cancer usually makes much more. An
elevated PSA may suggest that a malignant tumor is
present. False positive tests exist. For that reason
doctors really on the combination of a PSA blood test
and a DRE. If there is doubt, the physician may recommend
a sample of prostate tissue from a biopsy be taken
for further study. Some doctors don't think screening
for prostate cancer is worth doing. Downsides include
an extensive workup and treatment for a disease that
never would have shortened a life. The treatment options
for prostate cancer each have the potential for side
effects. Another argument against prostate cancer screening
is that it has never been proven to save lives in studies
of large populations. Many doctors think that newer
treatments for early stage prostate cancers will make
the screening process necessary by all standards.
Symptoms
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Most early prostate cancers
are detected with PSA tests or digital rectal exams
before they cause any symptoms. More advanced prostate
cancers can cause a variety of symptoms including:
- trouble
starting urination
- urinating much more frequently
than usual
- the feeling that you can't
release all of your urine
- pain on urination or
ejaculation
- blood in your urine or semen
- impotence
- bone pain
All of the symptoms listed
here can be caused by a number of things besides prostate
cancer. If the patient experiences any of these symptoms
further screening should be discussed.
Diagnosis
If the patient experience symptoms, the doctor will
do a digital rectal exam and a PSA blood test. If either
of those two tests is abnormal, the doctor will probably
recommend a biopsy. Once the tissue is removed, a pathologist
will review the specimen. The pathologist can tell
if it is cancer or not; and if it is cancerous, then
the pathologist will characterize it by what type of
prostate cancer it is and how abnormal it looks (known
as the grade).
Treatment
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There are many different ways to treat prostate cancer,
and consulting multiple types of doctors before making
a final decision. Physicians are not always in agreement
as to the way to proceed because there haven't been
enough large trials that compare the different treatment
modalities. A second opinion is standard. Talking with
both urologists and radiation oncologists to discuss
the benefits and risks of surgery, hormonal therapy,
and radiation treatment including brachytherapy, chemotherapy,
and cryosurgery is suggested. “Watchful Waiting” is
the choice of some patients and their physician in
the hopes it will be a slow growing cancer. Once a
patient has been treated for prostate cancer follow
up visits are done on a regular schedule, often at
first then less often as the patient is free of the
disease.
The following information is provided for a
better understanding of the disease and does not replace
the dialogue men should have with their physician regarding
screening and treatment for prostate cancer.
Adapted from OncoLink, University of Pennsylvania |
