Adverse effects of PC-SPES treatment were similar to those of hormonal drugs. The percentages indicate the approximate low-to-high range of side effects reported in the studies. It is difficult to compile accurate numbers from all studies reporting side effects because they are not consistently reported. Some studies concatenated categories of side effects, some did not report specific numbers or percentages, and some reported a few side effects while not reporting others. The following references indicate the studies from which the percentages come:

• Gynecomastia (8%–8.7%).[1-6]
• Nipple tenderness (34.8%–100%).[1-7]
• Dyspepsia/nausea (15.7%–21.7%).[2-7]
• Fatigue (8%–17.1%).[1-5]
• Diarrhea (13%–38.6%).[1-5]
• Leg cramps/swelling (2%–68.5%).[1-5]
• Cardiovascular problems/angina (4.3%–7%).[1-5]
• Hot flashes (4.3%–34%).[1-5]
• Decreased libido (6.2%–100%).[5,7]
• Erectile dysfunction (single case report).[8]
• Thromboembolic effects (5%–6.2%).[5,6]

References

1. 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.  [PUBMED Abstract]
   
   
2. Oh WK, George DJ, Kantoff PW: Rapid rise of serum prostate specific antigen levels after discontinuation of the herbal therapy PC-SPES in patients with advanced prostate carcinoma: report of four cases. Cancer 94 (3): 686-9, 2002.  [PUBMED Abstract]
   
   
3. 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.  [PUBMED Abstract]
   
   
4. 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.  [PUBMED Abstract]
   
   
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.  [PUBMED Abstract]
   
   
6. 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.  [PUBMED Abstract]
   
   
7. DiPaola RS, Zhang H, Lambert GH, et al.: Clinical and biologic activity of an estrogenic herbal combination (PC-SPES) in prostate cancer. N Engl J Med 339 (12): 785-91, 1998.  [PUBMED Abstract]
   
   
8. Moyad MA, Pienta KJ, Montie JE: Use of PC-SPES, a commercially available supplement for prostate cancer, in a patient with hormone-naive disease. Urology 54 (2): 319-23; discussion 323-4, 1999.  [PUBMED Abstract]
   
   

Glossary Terms

An unwanted side effect of treatment.

Having to do with the heart and blood vessels.

A detailed report of the diagnosis, treatment, and follow-up of an individual patient. Case reports also contain some demographic information about the patient (for example, age, gender, ethnic origin).

Frequent and watery bowel movements.

An inability to have an erection of the penis adequate for sexual intercourse. Also called impotence.

A condition marked by extreme tiredness and inability to function due lack of energy. Fatigue may be acute or chronic.

One of many chemicals made by glands in the body. Hormones circulate in the bloodstream and control the actions of certain cells or organs. Some hormones can also be made in the laboratory.

A sudden, temporary onset of body warmth, flushing, and sweating (often associated with menopause).

In anatomy, the small raised area in the center of the breast through which milk can flow to the outside.

A mixture of eight herbs that has been sold as a dietary supplement and promoted as a way to keep the prostate healthy and to treat prostate cancer. PC-SPES has been studied in the treatment of prostate cancer, but has been taken off the market in the U.S. because of safety concerns.

A problem that occurs when treatment affects healthy tissues or organs. Some common side effects of cancer treatment are fatigue, pain, nausea, vomiting, decreased blood cell counts, hair loss, and mouth sores.