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Clinical Trials at UCSF PC-SPES Tests Positive for Estrogen, Lowers Testosterone Nov 1998 Urology 1999 Aug; 54(2):319-23 Use of PC-SPES ... in a patient with hormone-naive disease Moyad MA, Pienta KJ, Montie JE Department of Surgery, University of Michigan Clinical and Biologic Activity of an Estrogenic Herbal Combination (PC-SPES) in Prostate Cancer Robert S. DiPaola, et al The New England Journal of Medicine September 17, 1998 Alternative Medicine The Risks of Untested and Unregulated Remedies The New England Journal of Medicine September 17, 1998

PC-SPES Update
The Herbal Therapy Lowers PSA in Men With Advanced Prostate Cancer, UCSF Study Shows

May 6 - July 9, 1999. -- Dr. Eric Small at the University of California San Francisco reports that PC-SPES, an herbal mixture, has significantly reduced prostate specific antigen (PSA) levels in a group of men with advanced prostate cancer.
     To date in this UCSF trial PC-SPES treatment has led to a drop PSA in a majority of men who had already stopped responding to standard hormonal therapy and in all men who had not yet received hormonal therapy. When taking PC-SPES, 75% of the men in the UCSF study experienced more than a 50% percent decline in their PSA levels.
     PC-SPES ("PC" stands for prostate cancer, "SPES" is Latin for hope) is a combination of eight Chinese herbs, the most common of which is Saw Palmetto. PC-SPES is commercially available as an over-the-counter drug for the treatment of prostate cancer.
     To date in the UCSF study a total of 61 men (27 with hormone-naïve prostate cancer; 34 with hormone-resistant prostate cancer) have been clinically evaluated for preliminary results. Study participants received 9 capsules daily of PC-SPES. Most of these men are still enrolled in the trial and continuing treatment at this time.
     "Our findings suggest that PC-SPES may have efficacy as a treatment for some men with prostate cancer," said Eric Small, MD, UCSF assistant clinical professor of medicine, co-author of the study. "However, as of yet, we cannot precisely pinpoint the estrogenic or active anti-cancer ingredients, if any, that PC-SPES may contain."
     The study's results are preliminary and require further evaluation and a longer follow-up period (minimum of two years), Dr. Small said. Most of the study participants had not yet been enrolled long enough to be evaluated at the time these results were announced. A total of seventy men have enrolled and begun treatment with PC-SPES.

  






   In addition to PSA drops, Small reports shrinkage of some of the men's prostate cancer tumors. Side effects of the compound noted in this study include impotency, lowered sex drive and breast tenderness -- typical conditions associated with hormonal therapies. Some men using PC-SPES report diarrhea and weight loss. Overall, the men enrolled in the UCSF study tolerated the drug quite well.
     PC-SPES appears to work in part like any other hormonal therapy for prostate cancer. Small says that it demonstrated an anti-testosterone effect in hormone-naïve prostate cancer patients by mimicking the female hormone, estrogen. The compound may contain other active anti-cancer ingredients, he says, since it also lowered PSA levels in men in the study whose tumors have become resistant to hormonal treatments.
     Prostate cancer cells start out using testosterone as fuel. Hormone therapy applies one or more methods of cutting off the supply of testosterone to the prostate gland and prostate cancer tumors. In Western medicine, the oldest method was by giving the male patient the female hormone estrogen. But estrogen in the doses required to have an effect on the cancer carries an unacceptable risk of causing deep-vein blood clots and other serious cardiovascular damage including heart attack.
     Initial hormonal blockade nowadays is usually achieved with regularly repeated injections of Lupron or Zoladex or by oral therapies such as as Casodex. As with estrogen, though, these newer hormonal blocks may eventually fail. A small population of cancer cells may survive without testosterone and may use the blocker for fuel. This stage of disease is called androgen-independent, hormone-resistant, or hormone-refractory prostate cancer. Whether PC-SPES fails in the same way and if so, at what point, has not yet been shown.
     "As our study continues, we ultimately hope to learn a number of things about PC-SPES," Small says. "For instance, we aim to determine what percentage of men with hormone-naïve and hormone-resistant prostate cancer have declines in their PSA levels with use of the herbal compound; how long the anti-cancer and PSA-lowering effects of PC-SPES lasts; what the short and long-term effects of the therapy are; and how declines in PSA correlate with other measures of anti-cancer activity such as changes in tumor imaging and scanning."


Complete listings to date of peer-reviewed publications on PC-SPES (at NCI's PUBMED)

Other authors on the paper include Robert Bok, MD, clinical instructor of medicine; Michele Corry, UCSF RNP; Mark Frohlich, MD, UCSF clinical instructor of medicine; Hiroko Kameda, UCSF research assistant; W.K. Kelly, MD, urologist oncologist at Memorial Sloan-Kettering Cancer Center; and David Reese, MD, UCSF assistant clinical professor of medicine. The PC SPES study is supported by the Association for the Cure of Cancer of the Prostate (CaP CURE).