Prostate Cancer Herbal Mixture Avoids Osteoporosis of Chemical Hormonal Blockade

May 13, 2001 -- PC-SPES, an herbal compound manufactured by BotanicLab of California and sold as a nutritional supplement, has activity in the treatment of prostate cancer. Tests have shown that the compound, made up of eight herbs, contains phyto-estrogen (estrogen of a "weak" form found in plants). The estrogen content, researchers say, may contribute to reduction of prostate cancer patients' PSA (prostate specific antigen).

Researchers at University of California San Francisco wondered if PC-SPES's estrogen content might protect men receiving hormonal blockade for prostate cancer against loss of bone mineral density.

"Bone mineral density loss is a concerning side effect of androgen deprivation therapy," says UCSF team leader Dr. Eric Small in a paper published May 12 in the Proceedings of the American Society of Clinical Oncology (ASCO). Bone density loss, or osteoporosis, is a common side effect of Lupron, Zoladex and other testosterone-blocking drugs for prostate cancer. It can lead to crippling fractures of hip and/or spine.

Patients with progressive androgen-dependent prostate cancer who were already enrolled in a clinical trial of PC-SPES at UCSF were evaluated also for changes in their bone mineral density. Thirty-three men were in this hormone-dependent group. Within about four and a half months of starting therapy, 15 of the men had their baseline bone mineral density measured by DEXA scan (dual-energy x-ray absorptiometry). The men took follow-up scans about eleven months after treatment began.

After one year on PC-SPES none of these men lost any bone mineral density even though their testosterone levels fell alogn with their PSA's. In spine, hip and femoral neck (key sites for osteoporosis and crippling fractures) the men actually gained bone mineral density, although the gains were not statistically significant.

"In this sample of men with hormone-dependent prostate cancer," the UCSF oncologists say, "PC-SPES did not significantly affect bone mineral density over one year. As with other forms of androgen deprivation therapy (ADT), both testosterone and PSA levels fell." Unless drugs called biphosphonates are taken for protection, standard androgen blockade with Lupron or Zoladex results in bone mineral density loss of "3-5% in the first year." More study is under way.

If the bone integrity advantage of PC-SPES holds up in larger studies, it will need to be weighed against other side effects. Typical side effects of PC-SPES, according to UCSF, are:

• Nipple tenderness
• breast enlargement
• loss of libido (decrease in desire to have sex)
• decrease in erections (in men not previously on testosterone-blocking therapy)
• "Frequent loose bowel movements or diarrhea -- usually mild, in about 1/3 of patients"
• Leg cramps or muscle cramps -- about 1/3 of patients
• Changes in urine flow
• Fatigue
• Blood clots in legs or lungs
• Allergic reactions. "A few patients have developed either face swelling, tongue swelling, difficulty swallowing, or possibly difficulty with breathing. In most cases, we think this is probably an allergic reaction to PC-SPES. There is nothing special that you need to do except to be aware of this, and should you develop any of these symptoms, please make sure that you get to an emergency room immediately. We would also recommend that you carry Benadryl (25 mg) with you at all times."

The Effect of the Herbal Supplement PC-SPES on Bone Mineral Density in Men with Prostate Cancer, R.W. Ross, S. Kussmaul, E. J. Small, University of California, San Francisco, CA.

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UCSF PC SPES "Medical Care & Info" page for patients on study.

PC-SPES Effects on Patients With Androgen Dependent Prostate Cancer Fox-Chase March 1, 2000.

PC-SPES UPDATE: Early Results of UCSF Phase II TriaL: Herbal Therapy Lowers PSA in Men With Advanced Prostate Cancer, Study Shows May 6-July 9, 1999

PC-SPES Contains Plant Estrogen November 26, 1998 Two sets of results from a New Jersey study of the herbal mixture PC-SPES show that it is strongly positive for estrogen.

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