PC-SPES for Prostate Cancer
PC-SPES is a combination of eight Chinese herbs:
- Isatis indigotica
- Glycyrrhiza glabra and Glycyrrhiza uralensis (licorice)
- Panax pseudo-Ginseng (ginseng)
- Ganoderma lucidum
- Scutellaria baicalensis (skull cap)
- Dendranthema morifolium Tzvel (chrysanthemum)
- Rabdosia rebescens
- Serenoa repens (saw palmetto)
These herbs possess anti-cancer, anti-inflammatory, antiviral and immune enhancement properties. Studies have shown that PC-SPES exhibits hormone-like properties and anti-prostate cancer effects. PC-SPES has been found to arrest the growth of prostate cancer cells by ten different biological mechanisms:
- Suppresses cancer cell growth
- Reduces intracellular PSA
- Reduces level of PSA secreted into blood
- Decreases the number of androgen receptors
- Decreases the intensity of binding to the androgen receptor
- Decreases clonogenicity (ability of cancerous cells to grow a colony of new cells)
- Slows the cell cycle and prevents tumor cells from going into the S phase (where DNA replication occurs)
- Causes programmed cell death (apoptosis)
- Down regulates BCL-2, which is a gene that resists cell death (apoptosis)
- Sensitizes radiation effects (Makes radiation therapy ineffective)
When prostate cancer patients stop responding to hormone withdrawal therapy, a secondary therapy is initiated. This secondary therapy can be chemotherapy and/or estrogen therapy. If the secondary therapy fails, PC-SPES can be chosen as a treatment option. PC-SPES has been shown in some patients to be effective even after estrogen therapy has failed.
Studies show that PC-SPES reduces PSA levels and suppresses prostate cancer cell growth. In a study published in the New England Journal of Medicine eight patients with androgen-dependent prostate cancer had decreased PSA and testosterone levels in response to PC-SPES. Their decreased levels were almost equivalent to the levels one would observe after LHRH (luteinizing-hormone releasing hormone) and estrogen treatment.
Additional studies have also been done on patients with androgen-independent prostate cancer. In one such study, the PSA levels had a median decline of 40% (after 8 months of PC-SPES). In another study, the effects of PC-SPES were investigated in test tubes, animals and humans. In the test tubes, the larger the dose of PC-SPES, the more cancer cell death (apoptosis) occurred.  Reduced tumor volume was observed in the animals treated with PC-SPES. Overall, the prostate cancer patients experienced a decrease in PSA serum levels. However, the patients also had side effects similar to those seen in estrogen treatment.
In a study by Small et al., nine (320 mg) capsules of PC-SPES were administered to patients per day (until toxicity resolved to grade 1 or less). 100% of the androgen-dependent prostate cancer patients experienced a decline in PSA 80% within a period of 57+weeks. 54% of the androgen-independent prostate cancer patients had a decline in PSA 50%. This year, Small and colleagues planned a randomized trial, comparing PC-SPES to DES (Diethylstilbestrol), an artificial estrogen. At the beginning of the trial, they began to notice that the men receiving PC-SPES were doing much better than the men receiving DES. In January, they discontinued the trial when they discovered that the DES was present in the lots of PC-SPES.
DES is used in advanced prostate cancer to block the production of testosterone, which fuels androgen-dependent prostate cancer. DES is a carcinogen, but can be used in small doses in combination with an anticoagulant to prevent blood clots in prostate cancer patients. However, the dosage must be strictly controlled and monitored.
PC-SPES exhibits strong estrogenic activity. Therefore, side effects of PC-SPES include breast tenderness and/or enlargement, leg and muscle cramps, diarrhea, fatigue, and impotence. More serious side effects are blood clots (in the legs or lungs), heart attack, and stroke. However, these side effects are typical for high-dose estrogen treatment. Some patients have had allergic reactions to PC-SPES. These patients experienced difficulty breathing and swelling of the face and tongue. Benadryl may be used to treat this allergic reaction. However, it is also strongly recommended that you go to an emergency room immediately.
Recent reports suggest that PC-SPES may be contaminated with unidentified substances. Reports from three laboratories show that DES was present in their samples of PC-SPES. On the opposing side, the California State Health Authorities have not found any DES in samples of PC-SPES. Some researchers argue that the FDA (Food and Drug Agency) and CDHS's (California Department of Health Services) testing may not be as sensitive as the other laboratories. Therefore, the low levels of DES are not detected. The DHS (Department of Health Services) had discovered a compound in PC-SPES that they believed was Warfarin, a blood thinner. BotanicLab lab reports showed that this unidentified compound may be Coumarin, an anti-coagulant, which may show up as Warfarin in laboratory tests. The presence of Coumarin may balance the clotting effects of estrogenic properties in PC-SPES. In addition, the licorice in PC-SPES may naturally contain Coumarin. At this time, PC-SPES has been recalled by its manufacturer (BotanicLab). It is recommended to avoid this herbal supplement until further research confirms the presence of DES in PC-SPES and until these recent allegations against PC-SPES have been either confirmed or refuted.
Note: It is important to remember that there are still several unanswered questions about PC-SPES. Further clinical research with PC-SPES is required for a determination of its long-term effects.
Urology Center Recommendation
- PC-SPES had been recalled by its manufacturer (BotanicLab). Do not take PC-SPES. If you are presently taking PC-SPES, please consult your physician immediately.
Click here to view information about saw palmetto.