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Human / Clinical Studies


    A prospective clinical series assessed the ability of PC-SPES to lower serum PSA levels in 33 prostate cancer patients. The patients had either refused conventional therapy or had failed previous cryosurgery, radiation therapy, and/or hormonal therapy. No overt signs of disease progression were found in any of the patients. At 2 months, PSA levels had decreased by a mean of 52% in 27 of the 31 patients and had increased in two patients. Of the five patients who had hormone -refractory disease, all had decreased serum PSA levels. Reviewed in [3,6]

    In a continuation of the previous study, a total of 69 patients with either AI or AD disease were separated into three study groups. Group one (n = 43) had undergone previous therapy, including hormonal; group two (n = 22) developed AI after treatment; and group three (n = 4) had not undergone previous therapy. The study assessed PC-SPES activity in suppressing PSA levels. Patients were given three capsules of PC-SPES 3 times per day. PSA levels and side effects were observed for 24 months.[7]

    In group one, 82% of patients (32 of 39) had a decrease in PSA levels, with 20 patients having a decrease of greater than 50% at 2 months' follow-up; the decrease lasted for 24 months in two patients. In group two (AI patients), 90% (19 of 21) had a decrease in PSA at their 2-month follow-up, with 66% (14 of 21) having a decrease of greater than 50% in PSA levels. At 24 months, two patients had a decrease of 20% to 50% in pretreatment PSA levels. In group three, 50% (2 of 4) had a decrease of greater than 50% in PSA levels at 2 months, and the remaining two patients had an increase at 2 and 6 months. Eighty-two percent of study patients had a decreased PSA level after 2 months of therapy. Side effects included nipple tenderness (42%), gynecomastia (8%), hot flashes, and deep venous thrombosis.[7] In both Germany and the United Kingdom, PC-SPES–like formulations have been studied. A phase I trial of PC-Spes2 in the United Kingdom encountered tolerability problems due to diarrhea.[8]


    1. Oh WK, Kantoff PW, Weinberg V, et al.: Prospective, multicenter, randomized phase II trial of the herbal supplement, PC-SPES, and diethylstilbestrol in patients with androgen-independent prostate cancer. J Clin Oncol 22 (18): 3705-12, 2004.
    2. Oh WK, George DJ, Hackmann K, et al.: Activity of the herbal combination, PC-SPES, in the treatment of patients with androgen-independent prostate cancer. Urology 57 (1): 122-6, 2001.
    3. Pirani JF: The effects of phytotherapeutic agents on prostate cancer: an overview of recent clinical trials of PC SPES. Urology 58 (2 Suppl 1): 36-8, 2001.
    4. Pfeifer BL, Pirani JF, Hamann SR, et al.: PC-SPES, a dietary supplement for the treatment of hormone-refractory prostate cancer. BJU Int 85 (4): 481-5, 2000.
    5. Small EJ, Frohlich MW, Bok R, et al.: Prospective trial of the herbal supplement PC-SPES in patients with progressive prostate cancer. J Clin Oncol 18 (21): 3595-603, 2000.
    6. de la Taille A, Hayek OR, Buttyan R, et al.: Effects of a phytotherapeutic agent, PC-SPES, on prostate cancer: a preliminary investigation on human cell lines and patients. BJU Int 84 (7): 845-50, 1999.
    7. de la Taille A, Buttyan R, Hayek O, et al.: Herbal therapy PC-SPES: in vitro effects and evaluation of its efficacy in 69 patients with prostate cancer. J Urol 164 (4): 1229-34, 2000.
    8. Shabbir M, Love J, Montgomery B: Phase I trial of PC-Spes2 in advanced hormone refractory prostate cancer. Oncol Rep 19 (3): 831-5, 2008.

    This information is produced and provided by the National Cancer Institute (NCI). The information in this topic may have changed since it was written. For the most current information, contact the National Cancer Institute via the Internet web site at http:// cancer .gov or call 1-800-4-CANCER.

    WebMD Public Information from the National Cancer Institute

    Last Updated: February 25, 2014
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