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Other common
name(s): PC PLUS, Prostasol
Scientific/medical
name(s): none
Description
PC-SPES was a formula consisting of a combination of 8 herbs
that contained a range of plant chemicals including flavonoids,
alkanoids, polysaccharides, amino acids, and trace minerals such as
selenium, calcium, magnesium, zinc, and copper. The 8 herbs used were
chrysanthemum, isatis, licorice, Ganoderma lucidum, Panax
pseudo-ginseng, Rabdosia rubescens, saw palmetto, and skullcap (see Licorice,
and Saw Palmetto),
although other compounds were found in the formula.
PC stands for prostate cancer, and SPES is the Latin word for
hope. PC-SPES was removed from the U.S. market in February 2002. The
U.S. Food and Drug Administration (FDA) issued a warning for people to
stop using the product because PC-SPES capsules were found to contain
prescription drugs that could cause serious health problems.
Since then, several new herbal products for prostate cancer
have been developed. The 2 most popular of these are PC-HOPE and
PC-CARE. A similar product is Prostasol, previously sold as PC-PLUS.
PC-HOPE includes the following ingredients: magnesium, sterolins,
quercetin, “proprietary blend”, Reishi (as
Ganoderma Lucidum), Baikal Skullcap (as Scutellaria Baicalensis),
Rabdosia (as Rabdosia rubescens Hara). Dyer's Woad (as Isatis
Indigotica Fortune), Mum (as Dendranthema Morifolium Tzelev), Saw
Palmetto (as Serenoa Repens), San-Qi Ginseng (as Panax Notoginseng),
and Licorice (as Glycyrrhiza Glabra L). The company that produces this
product recommends starting with 2 to 6 tablets daily, and gradually
reducing the dose over a period of months.
The ingredients of PC-CARE are listed as: "Proprietary Blend",
Reishi, Balkal Skullcap, Rabdosia Rubescens, Isatis indigotica,
Chrysanthemum, Saw Palmetto, Rye, and Licorice. The company producing
this product recommends 3 tablets daily.
Overview
Several carefully designed clinical trials found that PC-SPES
was an effective treatment for patients with prostate cancer, including
some whose cancer did not respond to conventional hormone therapy.
Common side effects included breast enlargement and tenderness, hot
flashes, and decreased libido. Blood clots were a less common but more
serious side effect. However, because the production process for
PC-SPES did not offer adequate protection against contamination, this
product is no longer available.
Newer products, such as PC-HOPE and PC-CARE, contain many of
the same ingredients as PC-SPES. However, because of limitations in the
way herbal products are regulated in the United States, patients and
clinicians cannot make any assumptions regarding the purity, safety, or
effectiveness of these new products. More research is needed to
evaluate them.
How is it promoted for use?
PC-SPES was promoted as a treatment for prostate cancer.
Proponents claimed that the herbal preparation could prevent or delay
the recurrence of prostate cancer, inhibit the growth of prostate
tumors, lengthen the survival time of prostate cancer patients, improve
the effectiveness of conventional treatments, and delay the need for
treatment with chemotherapy.
PC-HOPE, PC-CARE, and Prostasol (previously known as PC-PLUS)
are promoted in similar ways.
What does it involve?
These herbal formulations for prostate cancer treatment come
in capsules and are taken daily, in varying dosages. PC-SPES is no
longer produced. PC-HOPE and PC-CARE are available in health food
stores, from some nutritionists, and directly from manufacturers.
What is the history behind it?
PC-SPES was developed in the early 1990s by a chemist named
Sophie Chen, PhD, who claimed to have developed the formula by
integrating modern science and ancient Chinese herbal wisdom. By the
mid 1990s, the formula was widely promoted in the United States and was
named PC-SPES. Production of PC-SPES was stopped in 2002 when it was
found to be contaminated with varying amounts of 3 prescription drugs:
warfarin (an anticoagulant), diethylstilbesterol (DES, an estrogen-like
hormone), and indomethacin (an anti-inflammatory drug). PC-HOPE,
PC-CARE, and Prostasol became popular after production of PC-SPES was
halted.
What is the evidence?
PC-SPES has been carefully evaluated in several clinical
trials. In virtually all of these studies, PC-SPES was found to be
effective in reducing blood levels of prostate-specific antigen (PSA),
a protein secreted by cancerous prostate cells that is widely used by
doctors as a measure of whether prostate cancer is responding to
treatment or continuing to grow and spread. Several studies also
observed shrinking in tumors following treatment.
A randomized clinical trial comparing PC-SPES and
diethylstilbesterol (DES, an estrogen-like hormone) was started before
PC-SPES's problems with contamination were known, and results were
published in 2004. DES is sometimes used as a hormonal treatment for
prostate cancer that is no longer responding to treatments that block
production of male hormones or the effects of those hormones. Although
some of the PC-SPES tablets used in the study were later found to be
contaminated with DES or other estrogenic prescription drugs, the
herbal product was actually more effective than DES pills in lowering
blood PSA levels and in delaying growth of the cancer. The men
receiving PC-SPES were at lower risk for blood clots than those taking
DES.
Prior to its removal from the market, laboratory studies of
PC-SPES looked at how its ingredients blocked the growth of prostate
cancer cells. Substances from some of the ingredients acted as
phytoestrogens (estrogen-like substances found in plants) and blocked
the growth of prostate cancer cells. Prostate cancer cells are fueled
by androgens (male hormones) and slowed by estrogens (female hormones).
Some ingredients may have helped to activate the immune system. Still
others acted in ways not yet completely understood, but which appeared
to involve mechanisms other than acting as estrogens.
A few laboratory studies of PC-HOPE and PC-CARE have been
published, and these studies suggest they are active against prostate
cancer cells. Two European clinical studies of PC-HOPE suggest it may
improve patients' quality of life and lower their PSA levels. These 2
studies are summarized in press releases on the Internet, but as of
mid-2008 the detailed results had not yet been published in medical
journals.
Before PC-SPES was removed from the market, many prostate
specialists considered it a reasonable option for treating men whose
prostate cancers are androgen-independent, meaning they are no longer
responding to treatments that block production or activity of male
hormones. PC-SPES was not recommended for cancers that were still
responding to conventional hormonal treatments or for men with
localized prostate cancer that could be treated with surgery or
radiation therapy.
The role of newer herbal formulations currently remains
uncertain, because U.S. laws permit companies to sell these products
without providing detailed information on safety and effectiveness (as
would be required for new drugs). It will probably take a few years for
prostate cancer researchers to complete clinical studies of PC-HOPE and
PC-CARE similar to those they had done on PC-SPES.
Are there any possible problems or
complications?
This product is sold as a
dietary supplement in the United States. Unlike companies that produce
drugs (which must provide the FDA with results of detailed testing
showing their product is safe and effective before the drug is approved
for sale), the companies that make supplements do not have to show
evidence of safety or health benefits to the FDA before selling their
products. Supplement products without any reliable scientific evidence
of health benefits may still be sold as long as the companies selling
them do not claim the supplements can prevent, treat, or cure any
specific disease. Some such products may not contain the amount of the
herb or substance that is written on the label, and some may include
other substances (contaminants). Though the FDA has written new rules
to improve the quality of manufacturing processes for dietary
supplements and the accurate listing of supplement ingredients, these
rules do not take full effect until 2010. And, the new rules do not
address the safety of supplement ingredients or their effects on health
when proper manufacturing techniques are used.
Most such
supplements have not been tested to find out if they interact with
medicines, foods, or other herbs and supplements. Even though some
reports of interactions and harmful effects may be published, full
studies of interactions and effects are not often available. Because of
these limitations, any information on ill effects and interactions
below should be considered incomplete.
Side effects associated with the use of PC-SPES included
increased breast size and nipple tenderness or pain and a reduced sex
drive. There was also an increased risk of blood clots, which are
potentially fatal. Since PC-HOPE, Prostasol, and PC-CARE are reported
to be quite similar to PC-SPES, side effects may also be similar.
As with all herbs, allergic reactions are possible. In
addition, the potential interactions between herbs and other drugs and
herbs should be considered. Some of these combinations may be
dangerous. Always tell your doctor and pharmacist about any herbs you
are taking. Relying on this type of treatment alone and avoiding or
delaying conventional medical care for cancer may have serious health
consequences.
Additional Resources
More information from your American Cancer
Society
The following information on complementary and alternative
therapies may also be helpful to you. These materials may be found on
our Web site (www.cancer.org)
or ordered from our toll-free number (1-800-ACS-2345).
References
Bigler D, Gulding KM, Dann R, Sheabar FZ, Conaway MR,
Theodorescu D. Gene profiling and promoter reporter assays: novel tools
for comparing the biological effects of botanical extracts on human
prostate cancer cells and understanding their mechanisms of action. Oncogene.
2003;22:1261-1272.
de la Taille A, Buttyan R, Hayek O, Bagiella E, Shabsigh A,
Burchardt M, Burchardt T, Chopin DK, Katz AE. Herbal therapy PC-SPES:
in vitro effects and evaluation of its efficacy in 69 patients with
prostate cancer. J Urol.
2000;164:1229-1234.
DiPaola RS, Zhang H, Lambert GH, Meeker R, Licitra E, Rafi MM,
Zhu BT, Spaulding H, Goodin S, Toledano MB, Hait WN, Gallo MA. Clinical
and biologic activity of an estrogenic herbal combination (PC-SPES) in
prostate cancer. N Engl
J Med. 1998;339:785-791.
Guns ES, Goldenberg SL, Brown PN. Mass spectral analysis of
PC-SPES confirms the presence of diethylstilbestrol. Can J Urol.
2002;9:1684-1688; discussion 1689.
Ikezoe T, Chen S, Saito T, Asou H, Kyo T, Tanosaki S, Heber D,
Taguchi H, Koeffler HP. PC-SPES decreases proliferation and induces
differentiation and apoptosis of human acute myeloid leukemia cells. Int J Oncol.
2003;23:1203-1211.
Natural Standard. Herbal/plant therapies: PC-SPES.
Complementary/Integrative Medicine Education Resources, The University
of Texas M.D. Anderson Cancer Center Web site.
http://www.mdanderson.org/departments/cimer/display.cfm?id=66d17404-09ad-443e-b865bcfc6b635507&method=displayfull.
Accessed June 6, 2008.
Nelson PS, Montgomery B. Unconventional therapy for prostate
cancer: good, bad or questionable? Nat
Rev Cancer. 2003;3:845-858.
Oh WK, George DJ, Hackmann K, Manola J, Kantoff PW. Activity
of the herbal combination, PC-SPES, in the treatment of patients with
androgen-independent prostate cancer. Urology.
2001;57:122-126.
Oh WK, Kantoff PW, Weinberg V, Jones G, Rini BI, Derynck MK,
Bok R, Smith MR, Bubley GJ, Rosen RT, DiPaola RS, Small EJ.
Prospective, multicenter, randomized phase II trial of the herbal
supplement, PC-SPES, and diethylstilbestrol in patients with
androgen-independent prostate cancer. J Clin Oncol.
2004;22:3705-3712.
Pfeifer BL, Pirani JF, Hamann SR, Klippel KF. PC-SPES, a
dietary supplement for the treatment of hormone-refractory prostate
cancer. BJU Int.
2000;85:481-485.
PC-SPES. Memorial Sloan-Kettering Cancer Center Web site.
http://www.mskcc.org/mskcc/html/69326.cfm. Updated August 7, 2007.
Accessed June 6, 2008.
PC-SPES (PDQ). National Cancer Institute Web site.
http://www.nci.nih.gov/cancertopics/pdq/cam/pc-spes/HealthProfessional/page1.
Updated April 23, 2008. Accessed June 6, 2008.
Small EJ, Frohlich MW, Bok R, Shinohara K, Grossfeld G,
Rozenblat Z, Kelly WK, Corry M, Reese DM. Prospective trial of the
herbal supplement PC-SPES in patients with progressive prostate cancer.
J Clin Oncol
. 2000;18:3595-3603.
Sovak M, Seligson AL, Konas M, Hajduch M, Dolezal M, Machala
M, Nagourney R. Herbal composition PC-SPES for management of prostate
cancer: identification of active principles. J Natl Cancer Inst.
2002;94:1275-1281.
Note: This information may not cover
all possible claims, uses, actions, precautions, side effects or
interactions. It is not intended as medical advice, and should not be
relied upon as a substitute for consultation with your doctor, who is
familiar with your medical situation.
Last Medical Review: 11/01/2008
Last Revised: 11/01/2008
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