LAJOLLA, CALIFORNIA. The herbal compound, PC-SPES, was touted as an effective prostate cancer cure in the mid- to late 1990s. Many patients and alternative medicine practitioners reported excellent results with it. By the summer of 2001 reports began to appear on the Internet of possible contamination with diethylstilbestrol, a synthetic form of estrogen. The California Department of Health Services tested several lots of PC-SPES and found that they were contaminated with diethylstilbestrol and warfarin. In February 2002 the Health Services issued a warning about the product and its manufacturer, BotanicLab, voluntarily recalled it. BotanicLab went out of business in June 2002 and PC-SPES is no longer available.
Researchers at the University of California obtained several lots of PC-SPES manufactured between 1996 and 2001. They tested them and found that they, particularly the early lots, were effective in killing prostate cancer cells. They also found that the early lots were heavily contaminated with diethylstilbestrol and the anti-inflammatory drug indomethacin (Indocin). In July 1998, warfarin, an anticoagulant began to appear in the product in quantities that could affect blood clotting.
The researchers conclude that phytochemical (herbal) compounds may well have a place in the treatment of
prostate cancer, but that manufacturing practices and quality control procedures need to be vastly improved
before such compounds can be reliably tested in clinical trials.