Prostate cancer
Decreased Incidence of Prostate
Cancer With Selenium
Supplementation: Results of a
double-blind cancer prevention trial.
A study recently published in the British Journal of Urology (1998:81;730-734) examined
the relationship between dietary selenium and the incidence of prostate cancer. The study,
led by Dr. Larry Clark of the Arizona Cancer Center of the College of Medicine at the
University of Arizona, was conducted at several U. S. clinical centers.
A total of 974 men were randomized to
either a daily dietary supplement of 200 micrograms of selenium (supplied as a half-gram
high selenium yeast tablet) or a placebo. Patients were treated for a mean of 4.5 years
and followed for a mean of 6.5 years. Even though the first participants entered the study
in 1983, before PSA measurements were routinely available, frozen blood samples taken upon
entry into the study were used to determine PSA values for most participants. The PSA
values stratification by the initial PSA level, eliminating the possibility of a favorable
distribution of patients with elevated PSA levels (i. e. prevalent prostate cancer cases)
for the treatment group.
The selenium supplements were associated
with a significant 63% reduction in prostate cancer incidence. There were 13 prostate
cancer cases in the placebo group (relative risk, RR=0.37, P=0.0002). Restricting the
analysis to the 843 patients with normal initial PSA levels, only four cases were
diagnosed in the selenium-supplemented group and 16 cases diagnosed in the placebo group
after a two-year treatment lag (RR=0.26 P=0.009). The incidence of several other cancers
were also significantly decreased.
Source: http://www.seleniumresearch.com/
Studies continue to confirm that people
with higher levels of selenium in their blood have lower rates of prostate and lung
cancers. (Vogt, T. M., et al., Int. J. Cancer 2003;103(5):664-70). A new study confirms
that selenium supplementation reduces damage to DNA in prostate cells (Waters, D. J., et
al., J. Natl. Cancer Inst. 2003;95(3):237-41)
Continued studies in China confirm that
those with low levels of selenium before selenium supplementation had significantly
lowered incidence of lung cancer due to selenium supplementation. (Reid, M. E., et al.,
Cancer Epidemiol. Biomarkers Prev. 2002;(11):1285-91). This finding is also supported by a
Finnish study showing that low selenium levels lead to an increased incidence of lung
cancer. (Hartman, T. J., et al., Cancer Causes Control 2002;13(10):923-8).
In the Netherlands, former smokers with
high levels of selenium experienced half as many bladder tumors as their counterparts with
low selenium levels. An Indian study found that those with low levels of selenium have
significantly more head and neck cancers than those with higher selenium levels. (Yadav,
S. P., et al., J. Otolaryngol. 2002;31(4):216-9)
It is important to note, too, that the
reduced levels of prostate specific antigen (PSA), a commonly used marker for prostate
cancer, observed with selenium supplementation is due entirely to the effect of selenium
on the cancer cells and not due to selenium interfering with the production of PSA for any
reason other than a decrease in cancer cells. "Changes in serum PSA levels in an
individual during selenium supplementation is not an effect specific for PSA secretion,
but rather is a useful indicator for changes in the disease progression in individual
patients." (Bhamre, S., et al., Prostate 2003;54:315-21)
GVAX in Advanced Prostate Cancer
Patients Made
Lymphopenic study
Purpose
Androgen (a male sex hormone) deprivation
is the standard therapy for metastatic prostate cancer and results in regression or
control of disease in 80-85% of patients. This hormone therapy results in a
progression-free survival of 12-18 months and overall survival of 24-30 months. However,
all patients ultimately develop hormone-refractory prostate cancer (HRPC). Management of
HRPC patients is a significant challenge for both patient and physician. Neither past nor
current chemotherapy regimens have shown curative potential in patients with HRPC. Thus
new treatment strategies are a high priority.
A major focus of new treatment strategies
is to enlist the aid of the immune system, particularly the development of prostate cancer
vaccines. There has been a number of studies using dendritic cell based vaccines and the
treatment has been well tolerated. Specific T-cell immune responses have been observed and
occasional evidence for tumor regression. A reduction in serum prostate-specific antigen
(PSA) has been observed as well. Lengthening the time-to-progression and delays in the
onset of bone pain have been observed in subsets of patients with HRPC.
The initial preclinical observations
suggesting that a granulocyte-macrophage colony-stimulating factor (GM-CSF) gene
transduced allogeneic (GVAX) prostate cancer vaccine may be efficacious in poorly
immunogenic cancers were reported.
More
New Vitamin D
Pill Improves Prostate Cancer Survival
Taking an experimental, high-dose vitamin
D pill in combination with chemotherapy can help extend the lives of men with advanced
prostate cancer, says a study presented Wednesday at the annual meeting of the European
Cancer Conference in Paris.
The study of 250 patients found that
those who took the DN-101 pill with chemotherapy lived about eight months longer than men
who took a placebo with chemotherapy.
"When DN-101 is added to
chemotherapy, it provides a significant improvement in survival for advanced prostate
cancer patients. DN-101 extends lives and it may also protect against side effects of
chemotherapy, providing a one-two punch in cancer therapy," Dr. Thomasz Beer,
national leader of the clinical trial and director of the Prostate Cancer Program at the
Oregon Health & Sciences University (OHSU) Cancer Institute, said in a prepared
statement.
"This is both surprising and
pleasing. A cancer treatment that improves survival and decreases toxicity is exceedingly
rare," Beer added.
DN-101 was designed specifically as a
cancer therapy. It's a form of calcitriol, a naturally occurring hormone and the
biologically active form of vitamin D.
Bron: http://www.healthfinder.gov
Vital Information All Men Should
Know (Vernon Coleman)
Prostate cancer is almost certainly the commonest type of cancer to affect men - and it is
now believed to affect one in three men over the age of 50. In America (where doctors test
for it regularly) it is the most frequently occurring cancer. In the UK (where routine
tests are far less common and where, therefore, the disease almost certainly lies
undiscovered and unsuspected in many men), it is the third most common male cancer.
Half of all men who die (of anything)
also have cancer of the prostate (though most of them don't know).
It is said that prostate cancer is a
relatively slow growing cancer - and that because it frequently attacks older men they may
die of something else before the prostate cancer kills them.
Half of all men who die in their 60s
already have prostate cancer developing. And even 40% of men in their 50s who die from
something else have prostate cancer that they probably didn't know about.
But this isn't the whole story. Prostate
cancer can affect younger men, some types of prostate cancer are aggressive and grow quite
quickly and quite a lot of men do die of prostate cancer. Prostate cancer is a very
serious disease.
I have no doubt that it would be possible
to cut total cancer rates by a massive amount if the information I have detailed here were
made widely available.
Sadly, however, politicians and large
parts of the mainstream media constantly succumb to pressure from commercial interests and
so much of this evidence remains undiscussed in the media.
Full report here
Vegetables lower prostate cancer
risk
By Alka Agrawal, PhD
Vegetable intake, particularly intake of
cruciferous vegetables such as cauliflower and broccoli, substantially lowers the risk of
prostate cancer in men, according to a report published in the January 5th issue of the
Journal of the National Cancer Institute. Prostate cancer risk was not affected by fruit
intake.
Dr. Alan R. Kristal and colleagues at the
University of Washington, in Seattle, studied 628 men ages 40 to 64 who had been newly
diagnosed with prostate cancer, as well as 602 age-matched male controls. To assess the
men's dietary habits over a 3- to 5-year period, the researchers administered a food
frequency questionnaire that asked about usual consumption of 99 foods.
When Dr. Kristal's team considered total
vegetable intake, they found that men who ate 28 or more servings of vegetables a week had
a 35% lower risk of prostate cancer compared with men who ate fewer than 14 servings a
week.
In addition, men who ate three or more
servings of cruciferous vegetables a week had a 41% decreased risk of prostate cancer
compared with men who ate less than one serving per week, even after the researchers
accounted for total vegetable intake.
"It's a piece of strong evidence
that vegetables can protect against prostate cancer," Dr. Kristal told Reuters
Health. He pointed out that cruciferous vegetables, in particular, are high in
isothiocyanates, which activate enzymes present in all cells that detoxify carcinogens.
Although the strongest association in the
study was between intake of cruciferous vegetables and lowered prostate cancer risk, Dr.
Kristal says that eating a variety of vegetables is probably important in lowering the
risk.
Resource: J Natl Cancer Inst
2000;92:61-68., Reuters Health
Redox-sensitive
protein targets of selenium in prostate cancer prevention
Raghu
Sinha, Ph.D.
Biochemistry and Molecular
Biology
Penn State College of Medicine,
Hershey, PA 17033
Experimental and epidemiological data support that selenium is effective in reducing the
risk of prostate cancer. We hypothesize that naturally occurring organoselenium compounds
such as selenomethionine (SM) and synthetic compounds such as
1,4-phenylenebis(methylene)selenocyanate (p-XSC) target redox-sensitive signal
proteins thereby regulating the proliferative and / or apoptotic responses. Comparing the
two-dimensional electrophoretic profiles of AR+ and AR- LNCaP cell supernatant fractions,
following 24 hr treatment with SM and p-XSC revealed several differentially
expressed protein spots including; cofilin-2, a muscle specific pro-apoptotic protein. SM
treatment of AR- LNCaP cells induces cofilin-2 in a dose-dependent manner concurring with
our hypothesis.
http://www.huck.psu.edu/CrossOver2005/SinhaPoster.html
Growth Suppressing Effect of
Garlic Compound Diallyl Disulfide on Prostate Cancer Cell Line (PC-3) in Vitro
Arumugam ARUNKUMAR, Marati Radhakrishnan
VIJAYABABU, Palaniyandi KANAGARAJ, Karundevi BALASUBRAMANIAN, Maria Michael ARULDHAS, and
Jagadeesan ARUNAKARAN*
Department of Endocrinology, Dr. ALM PG
Institute of Basic Medical Sciences, University of Madras; Taramani, Chennai-600 113,
India. * To whom correspondence should be addressed. e-mail: j_arunakaran@hotmail.com
Prostate cancer is the most predominant
cancer in men and prostate cancer related death increases every year. Till date, there is
no effective therapy other than androgen ablation therapy. At this stage, induction of
apoptosis is considered as a better strategy to control cancer. Previous studies reported
that aged garlic extract suppresses cancer growth and enhances immune system against
cancer. In the present study, diallyl disulfide, oil soluble organosulfur compound of
garlic, was studied for its antiproliferative effect on prostate cancer cells in vitro.
The suppression of cell growth was demonstrated by [3H]thymidine incorporation assay.
Induction of DNA damage was assessed by agarose gel electrophoresis. The results showed
that diallyl disulfide inhibited the growth of prostate cancer cells in a dose dependent
manner, compared to the control. At 50 µM and 100 µM concentrations, diallyl disulfide
induced DNA damage in PC-3 cells.
It is concluded that diallyl
disulfide, component of aged garlic extract, inhibits proliferation of prostate cancer
cells through the induction of apoptosis.
Full report here
HDR Prostate Brachytherapy
Prostate cancer is well suited to
brachytherapy. The prostate gland is located under the bladder and in front of the rectum,
and it is imperative that the radiation be focused in the prostate to avoid serious side
effects. The prostate gland is also close enough to the skin that it can be easily
accessed by brachytherapy needles.
There are two major methods of prostate
brachytherapy, permanent seed implantation and high dose rate (HDR) temporary
brachytherapy. Permanent seed implants involve injecting approximately 100 radioactive
seeds into the prostate gland. They give off their radiation at a low dose rate over
several weeks or months, and then the seeds remain in the prostate gland permanently.
HDR temporary brachytherapy instead
involves placing very tiny plastic catheters into the prostate gland, and then giving a
series of radiation treatments through these catheters. The catheters are then easily
pulled out, and no radiactive material is left in the prostate gland. A
computer-controlled machine pushes a single highly radioactive iridium seed into the
catheters one by one. Because the computer can control how long this single seed remains
in each of the catheters, we are able to control the radiation dose in different regions
of the prostate. We can give the tumor a higher dose, and we can ensure that the urine
passage (urethra) and rectum will receive a lower dose. This ability to modify the dose
after the needles are placed is one of the main advantages of temporary brachytherapy over
permanent seed implants.
More info here
Nutrition and prostate cancer
advice
Prostate cancer is a modern disease, much
more common now than it was 50 years ago, and largely caused by what we eat, and how we
live. By optimizing health, and reversing the conditions which lead to the development of
prostate cancer, we would expect to at least see a slowing of the cancer, and improved
cancer control.
Everybody with prostate cancer can follow this plan, with individual modifications.
Sometimes it can be followed on its own in a watchful waiting program, but more often it
would be employed along with standard treatments to maximize the effectiveness of the
conventional therapy. It can also be used if a conventional treatment did not cure or
control the cancer. Patients who are malnourished, or have a reduced appetite and weight
loss should not follow this exact plan. They need a diet with more emphasis on extra
calories and protein.
More info here
FDA Approves New Drug for
Advanced Prostate Cancer
The Food and Drug Administration (FDA)
today approved the New Drug Application (NDA) that permits marketing of Plenaxis
(abarelix), a drug for advanced prostate cancer for patients who have no alternative
therapy. The drug, indicated for the treatment of the symptoms of men with advanced
prostate cancer who cannot take other hormone therapies and who have refused surgical
castration, will be marketed under a voluntary risk management program (RMP) agreed to and
administered by the sponsor that will restrict the use of Plenaxis to patients with
advanced prostate cancer, who have no alternative therapy, because of an increased risk of
serious, and potentially life-threatening, allergic reactions associated with its use.
About 5-10% of men with prostate cancer have the type of advanced, symptomatic disease
that would make them candidates for Plenaxis.
Plenaxis is a type of medicine (called a
gonadotropin-releasing hormone (GnRH) antagonist) that lowers the male hormone
testosterone, which is a key factor involved in most prostate cancer growth. The
effectiveness of Plenaxis in lowering testosterone production in men with advanced,
symptomatic prostate cancer was demonstrated in a study of 81 men. The study showed that
such patients could avoid surgical castration by undergoing at least 12 weeks of
treatment. Some of the men also experienced other benefits from the use of this product,
including decreased pain and relief from urinary problems. However, three of the 81
patients in the clinical trial experienced serious allergic reactions, one of which
included loss of consciousness.
The FDA and the manufacturer have agreed
that marketing of Plenaxis should be restricted to those patients with advanced,
symptomatic prostate cancer and who do not have other treatment options because of this
increased risk of serious, and potentially life-threatening, allergic reactions. Because
of the risk of low blood pressure and fainting as part of the allergic reaction to
Plenaxis, patients who receive the drug are to be monitored for at least 30 minutes after
receiving a dose of the drug in their health care provider's office setting. Moreover, the
manufacturer will not be distributing the drug through retail pharmacies; rather, the drug
will be distributed directly to physicians and hospital pharmacies enrolled in the
Plenaxis RMP.
Plenaxis is administered as an injection
into the muscles of the buttocks every two weeks for the first month of therapy, followed
by once every four weeks thereafter. Because the drug may stop working in certain
patients, doctors should perform blood tests about every two months to make sure Plenaxis
is working by keeping the level of testosterone low.
The most common side effects seen in the
clinical trial were hot flashes, sleep disturbances, pain, including back pain, breast
enlargement or pain, and constipation.
The Plenaxis RMP that the drug's
manufacturer will be implementing is designed to help ensure that patients and physicians
are fully informed of the risks and benefits of Plenaxis before using it. The RMP
emphasizes the need for doctors, patients and hospital pharmacists to work together to
maximize the benefit of Plenaxis and minimize the risk.
As part of the program, the sponsor will
only be distributing Plenaxis to physicians who attest to certain qualifications and are
enrolled in Praecis' Plenaxis PLUS (Plenaxis User Safety) Program. In addition the company
is establishing educational programs for physicians, patients, and hospital pharmacists
about the risks and benefits of Plenaxis. Patients will be asked to read and sign a
patient information leaflet before receiving the drug. The company will also establish a
system that collects and reports adverse events to FDA. Enrolled physicians should also
report serious adverse events to Praecis at 1-866-753-6294 or to FDA's MedWatch Program at
1-800-FDA-1088. Finally, the company will also be conducting studies an assessments of the
risk management program, including an assessment of the prescribing and actual use of
Plenaxis.
Plenaxis is marketed by Praecis
Pharmaceuticals Inc., Waltham, Mass.
