PROSTATE
CANCER
What
is prostate cancer?
The prostate, a gland found only in men, is about the size of a
walnut and is located in front of the rectum, behind the base of
the penis, and under the bladder. The prostate surrounds the upper
part of the urethra, the tube that carries urine and semen out of
the penis. Prostate cancer is a malignancy that develops from cells
of the prostate gland. Eventually the cancer cells may spread outside
the gland to other parts of the body. Most prostate cancers grow
very slowly (autopsy studies show that many men have prostate cancer
which neither they nor their doctor were aware of). But some prostate
cancers can spread quickly to other areas.
How
common is it?
Prostate
cancer is the most common cancer (excluding skin cancer) of American
men. The American Cancer Society estimates that in 1998 about 184,500
new cases of prostate cancer will be diagnosed in the United States,
and about 39,200 men will die of the disease. Prostate cancer is
the second leading cause of cancer death in men, exceeded only by
lung cancer.
What
are the causes or risk factors?
While the causes of prostate cancer are not yet completely understood,
researchers have found several factors that are consistently associated
with an increased risk of developing this disease. These risk factors
include:
Age:
The chance of having prostate cancer increases rapidly after age
50. More than 80% of all prostate cancers are diagnosed in men over
the age of 65.
Race
& Nationality: Prostate
cancer is about twice as common among African-American men as it
is among white American men. Also, prostate cancer is most common
in North America and northwestern Europe. It is less common in Asia,
Africa, Central America, and South America.
Diet:
Results
of most studies suggest that men who eat a lot of fat in their diet
have a greater chance of developing prostate cancer (however, these
men tend to eat fewer fruits and vegetables and more dairy products
which may be responsible for increasing risk rather than the amount
of fat itself.) Research also suggests that a diet high in calcium
and low in fructose (fruit sugar) increases prostate cancer risk.
Physical
activity: Regular
physical activity and maintaining a healthy weight may help reduce
prostate cancer risk. Family history: Prostate cancer seems to run
in some families, suggesting an inherited or genetic factor. Having
a father or brother with prostate cancer doubles a man’s risk of
developing this disease. The risk is even higher for men with several
affected relatives, particularly if their relatives were young at
the time of diagnosis.
Vasectomy:
Men who
have had a vasectomy (surgery to make men infertile) may have a
slightly increased risk for prostate cancer, but this link has not
been consistently found. In some studies that found this increase,
it was linked to men who were younger than 35 when they had a vasectomy.
Research to resolve this issue is still in progress.
Can
prostate cancer be prevented?
Many risk factors such as a man’s age, race, and family history
are beyond his control. But current information on prostate cancer
risk factors suggests that some cases might be prevented. One possible
risk factor that can be changed is diet. A diet low in fat and consisting
mostly of vegetables, fruits, and grains is associated with reduced
risk of prostate cancer. The American Cancer Society recommends
limiting your intake of high-fat foods from animal sources and choosing
most of the foods you eat from plant sources. Eat five or more servings
of fruits and vegetables each day. Bread, cereals, grain products,
rice, pasta, and beans are also recommended. These guidelines on
nutrition provide an overall healthful approach to eating that also
helps lower the risk for some other types of cancer.
Lycopenes, which
are found in especially high levels in some fruits and vegetables
also seem to lower prostate cancer risk, as does the mineral selenium.
These vitamin-like substances are antioxidants that help prevent
damage to DNA and may help lower prostate cancer risk. Tomatoes
(raw, cooked, or tomato products such as sauces or ketchup), grapefruit,
and watermelon are rich in lycopenes.
What
are the signs and symptoms?
Some prostate cancers may be found because of symptoms such as slowing
or weakening of the urinary stream or the need to urinate more often.
These symptoms are not specific, and can also be caused by benign
diseases of the prostate, such as nodular hyperplasia. Symptoms
of advanced prostate cancer include hematuria (blood in the urine),
swollen lymph nodes in the groin area, impotence (difficulty having
an erection), and pain in the pelvis, spine, hips, or ribs. Once
again, these symptoms may also be present with other diseases. It
is important, however, to know about risk factors so that appropriate
action can be taken such as changing a health behavior, or being
monitored closely for a potential cancer. And, because most cases
of early prostate cancer cause no symptoms, it is very important
to know your risk factors and to be screened for prostate cancer.
How
is prostate cancer diagnosed?
The American Cancer Society recommends that both prostate-specific
antigen (PSA) blood test and digital rectal examination (DRE) should
be offered annually, beginning at age 50 years, and to younger men
who are at high risk, such as those with two or more affected first
degree relatives (father and a brother, or two brothers) or African
Americans. Screening tests can often detect prostate cancer at an
early stage, when treatment is most likely to be successful. For
men appropriately treated for cancer that has not spread beyond
the prostate gland, the five-year relative survival rate is 100%.
For More Information
American Cancer
Society
1-800-ACS-2345
http://www.cancer.org
The ACS coordinates
the Man to Man Prostate Cancer Education and Support Program, to
provide men and their partners with factual information about prostate
cancer in a supportive environment. The program includes 155+ group
education and support programs, one-on-one visitation and telephone
support, a quarterly newsletter, awareness activities, and prostate
cancer publications.