Advances
Made In Prostate Cancer Detection And Therapy
September Is Prostate
Cancer Awareness Month
From a new chemotherapy
drug to improved means of early detection, prostate cancer breakthroughs
in the last year have enhanced a man's chances of surviving
the disease.
These advances are
expected to help make one of the most survivable forms of cancer
even less threatening, health experts predict.
That is a message
physicians are looking to share in September, which is Prostate
Cancer Awareness Month.
"Prostate cancer is
a very treatable disease if it's caught early," says Howard
Soule, executive vice president and chief science officer of
the Prostate Cancer Foundation.
A walnut-sized gland
located just below a man's bladder, the prostate's function
is to produce seminal fluid (the fluid that carries sperm).
More than 230,000
new cases of prostate cancer are diagnosed each year, according
to the National Prostate Cancer Coalition,
making it the second most commonly diagnosed cancer among US
men.
The best way to ensure
survival is to detect prostate cancer early. Although some 29,900
men are expected to die of the disease this year, most cases
are treatable with early detection, experts say.
Increasing
Survival with New Approaches
During the past 20
years, the survival rate for prostate cancer has shot up from
67 percent to 97 percent, due to improvements in early detection.
And within the past
year, research has found that one of the best tests for prostate
cancer can do an even better job.
The prostate specific
antigen (PSA) test looks for a protein produced by the cells
of the prostate. When the prostate gland enlarges, it produces
more of the antigen, giving physicians an unmistakable sign
that something might be amiss.
Under previous guidelines,
physicians would conduct a biopsy of the prostate if a man's
PSA score went above 4.0. But new research has found the rate
of increase in a patient's PSA level is more important than
the total score, says Jamie Bearse, a spokesman for the National
Prostate Cancer Coalition.
The finding was reported
recently in the New England Journal of Medicine.
"A high velocity in
the increase in PSA scores should sound the alarms and set off
little red lights," even if the total score is lower than 4.0,
Bearse says.
Based on this new
information, both the American Urological Society
and the American Cancer Society have dropped
the recommended age for men to begin annual prostate screenings,
from 50 to 40.
That way, physicians
will be better able to observe year-by-year changes as men age
and are more susceptible to prostate cancer.
Another small but
promising milestone in prostate cancer treatment was reached
in May, when the US Food and Drug Administration (FDA)
approved the use of the chemotherapy medication Taxotere,
Soule says.
Clinical trials involving
more than 1,000 men with advanced prostate cancer that did not respond
to traditional hormonal therapy found that Taxotere, combined
with the steroidal medication prednisone, extended survival
times an average of 2.5 months, compared to men on a traditional
regimen.
Taxotere works by
inhibiting tubulin, a protein that encourages cancer cells to
divide and reproduce. Side effects may include nausea, hair
loss, fluid retention, and tingling sensations in the extremities,
according to the FDA.
The promising news
is that Taxotere is the first chemotherapy drug found that can
tackle prostate cancer in its late stages.
"Nothing else in that
clinical setting had been shown to promote survival," Soule
says.
Taxotere also shows
potential when combined with dozens of medications that can
provide targeted therapy for the cancer and its effects, he
says.
"Now investigators
can add targeted therapies on top of Taxotere, in the hope of
prolonging survival even longer," Soule says.
In a report at this
year's meeting of the American Society of Clinical Oncology, a
large European study found that men who were in a high-risk
group for relapse benefitted from radiation therapy following
surgery. "Post-operative radiotherapy results in improved biochemical
and progression-free survival," the authors write.
These findings were
confirmed by a study presented last month by Italian
researchers in a publication of the American Society
for Therapeutic Radiology and Oncology. The results
showed that men with prostate cancer who receive radiation
therapy after surgery typically live longer than men who do
not receive early radiation treatment.
Link
With Obesity Studied
Another new advance
involved research by the American Cancer Society
that revealed a link between obesity and prostate cancer, Bearse
says.
Scientists found that
if a man has a body-mass index of 30 or more - the clinical
definition of obesity - he is one-third more likely to develop
prostate cancer. Physicians do not yet know why this is
so.
"One of the possibilities
is that when you have bad cholesterol (a byproduct of obesity),
your body also makes bad testosterone," Bearse says. "When you
have bad testosterone metabolizing in the prostate, you have
a greater risk of cancer."
Studies such as these
are critical to success in the fight against prostate - or any
type - of cancer, Soule says. He advises any man suffering from
prostate cancer to sign up for a clinical trial that tests new
therapies.
"We will not advance
this field without men participating in the clinical evaluation
of new drugs," he says.
Always consult your
physician for more information.
Online
Resources
(Our Organization
is not responsible for the content of Internet sites.)
American
Cancer Society
American
Prostate Society
American
Urological Society
Centers
for Disease Control and Prevention (CDC)
Healthfinder,
US Department of Health and Human Services (HHS)
National
Cancer Institute Prostate Cancer Information
National
Institutes of Health (NIH)
National
Library of Medicine
National
Prostate Cancer Coalition
|
September 2004
Advances
Made In Prostate Cancer Detection And Therapy
Increasing
Survival with New Approaches
Link
With Obesity Studied
Prostate
Cancer Detection
Online
Resources
Prostate
Cancer Detection
The National
Cancer Institute (NCI) states that prostate cancer
often does not cause symptoms for many years. By the time symptoms
occur, the disease may have spread beyond the prostate. When
symptoms do occur, they may include:
-
Frequent urination, especially
at night
-
-
Trouble starting or holding
back urination
-
A weak or interrupted flow
of urine
-
Painful or burning urination
-
Blood in the urine or semen
-
-
Frequent pain in the lower
back, hips, or upper thighs
These can be symptoms
of cancer, but more often they are symptoms of non-cancerous
conditions. It is important to check with a physician.
As a man gets older,
his prostate may grow bigger and block the flow of urine or
interfere with sexual function. This common condition, called
benign prostatic hyperplasia (BPH), is not cancer, but can cause
many of the same symptoms as prostate cancer.
Although BPH may not
be a threat to life, it may require treatment with medicine
or surgery to relieve symptoms. An infection or inflammation
of the prostate, called prostatitis, may also cause many of
the same symptoms as prostate cancer.
Two tests can be used
to detect prostate cancer in the absence of any symptoms. One
is the digital rectal exam (DRE), in which a physician
feels the prostate through the rectum to find hard or lumpy
areas.
The other is a blood
test used to detect a substance made by the prostate called
prostate specific antigen (PSA). Together, these tests can detect
many “silent” prostate cancers, those that have
not caused symptoms.
At present, however,
it is not known whether routine screening saves lives. The benefits
of screening and local therapy (surgery or radiation) remain
unclear for many patients.
Because of this uncertainty,
the NCI is currently supporting research to
learn more about screening men for prostate cancer. Currently,
researchers are conducting a large study to determine whether
screening men using a blood test for PSA and a DRE can help
reduce the death rate from this disease.
They are also assessing
the risks of screening. Full results from this study, the Prostate,
Lung, Colorectal, and Ovarian Cancer Screening Trial or PLCO,
are expected by 2015.
Neither of the screening
tests for prostate cancer is perfect, the NCI
states. Most men with mildly elevated PSA levels do not have
prostate cancer, and many men with prostate cancer have normal
levels of PSA. Also, the DRE can miss many prostate cancers.
The DRE and PSA test together are better than either test alone
in detecting prostate cancer.
The diagnosis of prostate
cancer can be confirmed only by a biopsy, the NCI
states. During a biopsy, a urologist removes tissue samples,
usually with a needle.
This is generally
done in the physician's office with local anesthesia. Then the
sample is sent to the lab in order to check for cancer cells.
Prostate cancer is
described by both grade and stage.
Grade describes how
closely the tumor resembles normal prostate tissue. Based on
the microscopic appearance of tumor tissue, pathologists may
describe it as low-, medium-, or high-grade cancer. One way
of grading prostate cancer, called the Gleason system, uses
scores of 2 to 10.
Another system uses
G1 through G4. In both systems, the higher the score, the higher
the grade of the tumor. High-grade tumors generally grow more
quickly and are more likely to spread than low-grade tumors.
Stage refers to the
extent of the cancer. Early prostate cancer, stages I and II,
is localized. It has not spread outside the gland. Stage III
prostate cancer, often called locally advanced disease, extends
outside the gland to the seminal vesicles. Stage IV means the
cancer has spread to lymph nodes and/or to other tissues or
organs.
Always consult your
physician for more information. |
