PC-SPES, a Dietary Supplement for the Treatment of Hormone-refractory Prostate Cancer

Objective: To assess the effectiveness of PC-SPES, a dietary supplement containing eight herbal extracts, which is a popular alternative therapy among patients with hormone-refractory prostate cancer; anecdotal reports claim that this agent provides relief of metastatic pain, improvements in quality of life and reduction of prostatic specific antigen (PSA) level.

Patients And Methods: Sixteen men treated for advanced metastatic prostate cancer (stage D3) with either orchidectomy or a luteinizing-hormone releasing hormone agonist, with or without anti-androgen, were enrolled into a prospective clinical trial to evaluate the possible toxic and beneficial effects of PC-SPES. After hormone-ablative therapy had failed, and with established disease progression, all patients received supplemental treatment with PC-SPES (2.88 g daily) for 5 months. Hormonal therapy was continued throughout the trial to avoid the known withdrawal effect of anti-androgen on PSA levels.

Results: The supplemental intake of PC-SPES was associated with significant (P<0.05-0.01) improvements in quality-of-life measures, reductions in patient's pain ratings (P<0.05-0.01), and a decline in PSA levels (P<0.01), with no major side-effects.

Conclusions: These results support the anecdotal reports of the beneficial effects of PC-SPES as a comparable alternative to current management regimens in hormone-refractory prostate cancer. However, no conclusions can be drawn about the long-term effects of this new herbal therapy.