prostate cancer
Prostate cancer is cancer that forms in tissues
of the prostate – a gland in
the male reproductive system
found below the bladder and in front
of the rectum. Prostate cancer usually occurs
in older men. Who
is at risk from prostate cancer?
The exact causes of prostate cancer are not known, and doctors often cannot
explain why one man develops prostate cancer and another does not. However,
it is clear that prostate cancer is not contagious and is impossible to
"catch" it from another person.
Research has shown that men with certain risk factors are more likely than
others to develop prostate cancer. A risk factor is something that may increase
the chance of developing a disease.
Studies have found the following risk factors for prostate cancer:
- Age. Age is the main risk factor for prostate cancer.
This disease is rare in men younger than 45. The chance of getting it
goes up sharply as a man gets older. In the United States, most men
with prostate cancer are older than 65.
- Family history. A man's risk is higher if his father
or brother had prostate cancer.
- Race. Prostate cancer is more common in African American
men than in white men, including Hispanic white men. It is less common
in Asian and American Indian men.
- Certain prostate changes. Men with cells called high-grade
prostatic intraepithelial neoplasia (PIN) may be at increased risk for
prostate cancer. These prostate cells look abnormal under a microscope.
- Diet. Some studies suggest that men who eat a diet
high in animal fat or meat may be at increased risk for prostate cancer.
Men who eat a diet rich in fruits and vegetables may have a lower risk.
Many of these risk factors can be avoided. Others, such as family history,
cannot be avoided. You can help protect yourself by staying away from known
risk factors whenever possible.
Scientists have also studied whether BPH, obesity, smoking, a virus passed
through sex, or lack of exercise might increase the risk for prostate cancer.
At this time, these are not clear risk factors. Also, most studies have
not found an increased risk of prostate cancer for men who have had a vasectomy,
i.e., surgery to cut or tie off the tubes that carry sperm
out of the testicles.
Most men who have known risk factors do not get prostate cancer. On the
other hand, men who do get the disease often have no known risk factors,
except for growing older.
If you think you may be at risk, you should talk with your doctor. Your
doctor may be able to suggest ways to reduce your risk and can plan a schedule
for checkups.
Screening for prostate cancer
Your doctor can check you for prostate cancer before you have any symptoms.
Screening can help doctors find and treat cancer early. But studies so far
have not shown that screening tests reduce the number of deaths from prostate
cancer. You may want to talk with your doctor about the possible benefits
and harms of being screened. The decision to be screened, like many other
medical decisions, is a personal one. You should decide after learning the
pros and cons of screening.
Your doctor can explain more about these tests:
- Digital rectal exam. The doctor inserts a lubricated,
gloved finger into the rectum and feels the prostate through the rectal
wall. The prostate is checked for hard or lumpy areas.
- Blood test for prostate-specific antigen (PSA). A
lab checks the level of PSA in a man's blood sample. A high PSA level
is commonly caused by BPH or prostatitis (inflammation
of the prostate). Prostate cancer may also cause a high PSA level.
The digital rectal exam and PSA test can detect a problem in the prostate.
They cannot show whether the problem is cancer or a less serious condition.
Your doctor will use the results of these tests to help decide whether to
check further for signs of cancer. Information about other tests is in the
"Diagnosis" section.
What are the signs and symptoms of prostate cancer?
A man with prostate cancer may not have any symptoms. For men who have symptoms
of prostate cancer, common symptoms include:
- Urinary problems
- Not being able to urinate
- Having a hard time starting or stopping the urine flow
- Needing to urinate often, especially at night
- Weak flow of urine
- Urine flow that starts and stops
- Pain or burning during urination
- Difficulty having an erection
- Blood in the urine or semen
- Frequent pain in the lower back, hips, or upper thighs
Most often, these symptoms are not due to cancer. BPH, an infection, or
another health problem may cause them. Any man with these symptoms should
tell his doctor so that problems can be diagnosed and treated as early as
possible. He may see his regular doctor or a urologist. A urologist is a
doctor whose specialty is diseases of the urinary
system.
How is prostate cancer diagnosed?
If you have a symptom or test result that suggests cancer, your doctor must
find out whether it is due to cancer or to some other cause. Your doctor
will ask about your personal and family medical history. You will have a
physical exam. You may have lab tests. Your visit may include a digital
rectal exam, a urine test to check for blood or infection, and a blood test
to measure PSA level.
You also may have other exams:
- Transrectal ultrasound. The doctor inserts a probe
into the man's rectum to check for abnormal areas. The probe sends out
sound waves that people cannot hear (ultrasound). The waves bounce off
the prostate. A computer uses the echoes to create a picture called
a sonogram.
- Cystoscopy. The doctor uses a thin, lighted tube
to look into the urethra and bladder.
- Transrectal biopsy. A biopsy
is the removal of tissue to look for cancer cells. It is the only sure
way to diagnose prostate cancer. The doctor inserts a needle through
the rectum into the prostate. The doctor takes small tissue samples
from many areas of the prostate. Ultrasound may be used to guide the
needle. A pathologist checks for cancer cells in the tissue.
You may want to ask the doctor these questions before having a biopsy:
- Where will the biopsy take place? Will I have to go to the hospital?
- How long will it take? Will I be awake? Will it hurt?
- What are the risks? What are the chances of infection or bleeding
after the biopsy?
- How long will it take me to recover?
- How soon will I know the results?
- If I do have cancer, who will talk to me about the next steps? When?
If cancer is not found
If the physical exam and test results do not suggest cancer, your doctor
may suggest medicine to reduce symptoms caused by an enlarged prostate.
Surgery also can relieve these symptoms. The surgery most often used in
such cases is transurethral resection of the prostate (TURP or TUR). In
TURP, an instrument is inserted through the urethra to remove prostate tissue
that is pressing against the upper part of the urethra and restricting the
flow of urine. You should talk to your doctor about the best treatment option.
If cancer is found
If cancer is present, the pathologist studies tissue samples from the prostate
under a microscope to report the grade of the tumor. The grade tells how
much the tumor tissue differs from normal prostate tissue. It suggests how
fast the tumor is likely to grow. Tumors with higher grades tend to grow
faster than those with lower grades. They are also more likely to spread.
One system of grading prostate cancer uses G1 through G4. Another way of
grading is with the Gleason score. The pathologist gives each area of cancer
a grade of 1 through 5. The pathologist adds the two most common grades
together to make a Gleason score. Or the pathologist may add the most common
grade and the highest (most abnormal) grade to get the score. Gleason scores
can range from 2 to 10.
Staging the disease
To plan your treatment, your doctor needs to know the extent (stage) of
the disease. The stage is based on the size of the tumor, whether the cancer
has spread outside the prostate and, if so, where it has spread.
You may have blood tests to see if the cancer has spread. Some men also
may need imaging tests:
- Bone scan. The
doctor injects a small amount of a radioactive substance into a blood
vessel. It travels through the bloodstream and collects in the bones.
A machine called a scanner detects and measures the radiation. The scanner
makes pictures of the bones on a computer screen or on film. The pictures
may show cancer that has spread to the bones.
- CT scan.
An X-ray machine linked to a computer takes a series of detailed pictures
of areas inside your body. Doctors often use CT scans to see the pelvis
or abdomen.
- MRI.
A strong magnet linked to a computer is used to make detailed pictures
of areas inside your body.
These are the stages of prostate cancer:
- Stage I. The cancer cannot be felt during a digital
rectal exam. It is found by chance when surgery is done for another
reason, usually for BPH. The cancer is only in the prostate.
- Stage II. The cancer is more advanced, but it has
not spread outside the prostate.
- Stage III. The cancer has spread outside the prostate.
It may be in the seminal vesicles. It has not spread to the lymph nodes.
- Stage IV. The cancer may be in nearby muscles and
organs (beyond the seminal vesicles). It may have spread to the lymph
nodes. It may have spread to other parts of the body.
Recurrent cancer is cancer that has come back (recurred) after a time when
it could not be detected. It may recur in or near the prostate. Or it may
recur in any other part of the body, such as the bones.
How is prostate cancer treated?
Read about how prostate cancer
is treated.
How can prostate cancer be prevented?
A healthy, low-fat diet may help to prevent prostate cancer, and vitamin
E, selenium and lycopene (found in tomatoes)
may offer protection. Related category
• HEALTH
AND DISEASE Source: National Cancer
Institute
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