PC-SPES Herbal Therapy for Prostate Cancer

James Metz, MD
Abramson Cancer Center of the University of Pennsylvania
Last Modified: November 1, 2001

There are numerous herbal therapies that are promoted for "prostate health" in the mass media. Some of these herbs include saw palmetto, PC-SPES, and lycopene. PC-SPES is a combination herbal preparation of eight different substances. It is not regulated by the Food and Drug Administration (FDA) because it is considered a food supplement and not a medication. It contains chrysanthemum, isatis, licorice, Ganoderma lucidum, Panex-pseudo-ginseng, Rabdosia rubescens, saw palmetto, and scutellaria. There is evidence that some of these compounds have similar activity to the female hormone, estrogen. Licorice appears to stick to the estrogen receptor sites on cells. Ginseng induces the expression of gene products classically stimulated by estrogen.

An article published in the New England Journal of Medicine evaluated 8 patients taking PC-SPES. It was found that the herbal combination caused the male sex hormone, testosterone, to decrease significantly in patients taking the supplement. All patients had a decrease in the prostate specific antigen (PSA) blood test that is used to screen and follow patients with prostate cancer. Also, patients experienced loss of libido, breast swelling, and breast tenderness. These same side effects are found when males are treated with medical doses of estrogen. Laboratory analysis of PC-SPES showed the herbal combination has potent activity similar to estrogen in yeast cells, mice, and humans.

It is clear PC-SPES does have important effects on the prostate gland that are not totally understood to date. Clinical studies are currently ongoing and more information is needed before PC-SPES can be recommended in the treatment of prostate cancer. Because many treatment decisions are based on the PSA blood test and PC-SPES can cause a decrease in its level, physicians must know when patients are using this therapy. It is important that physicians ask patients about the utilization of PC-SPES and patients inform their health care provider about their utilization. No one wants the wrong treatment recommendation because the physician was not informed of all herbal therapies used by the patient.

Please visit the OncoLink Complementary Treatments section for more information on unconventional medical therapies.