Prostate Cancer Supplement Contaminated

An herbal mixture that was widely used for the treatment of prostate cancer, but is no longer on the market, was contaminated with synthetic drugs.

That is the conclusion of a new study in the Journal of the National Cancer Institute.

The mixture, called PC-SPES, started being used in late 1996 and early 1997, says study author Dr. Robert Nagourney. It was sold as a dietary supplement "for prostate health," but was widely used to treat prostate cancer.

Early Results Were Promising

In the beginning, the mixture looked good, Nagourney says, who heads Rational Therapeutics Inc., a research and therapy institute focusing on alternative treatments.

"We were seeing genuine responses," he says. Patients with advanced prostate cancer were seeing a decline in their levels of PSA (prostate-specific antigen), a marker for the disease.

"But patients, meantime, were complaining of breast tenderness," Nagourney says.

To investigate, Nagourney and his co-workers obtained eight lots of PC-SPES, manufactured at different times between 1996 and last year, and analyzed them. They found all lots contaminated with indomethacin, a pain reliever, and most with diethylstilbestrol, a potent synthetic estrogen that accounted for the breast tenderness. Later, warfarin, a blood thinner, began appearing in the herbal mix.

Nagourney and his colleagues originally presented the information in April at a meeting of the American Association for Cancer Research. The paper in the recent Journal of the National Cancer Institute issue provides more detailed analysis.

Was the contamination by the manufacturer, BotanicLab, which has since gone out of business, accidental or deliberate?

Contamination Not Likely An Accident

Nagourney says he cannot tell for sure. However, he adds that it seems "highly improbable" the drugs would get there accidentally, especially since one is a potent pain reliever and prostate cancer patients are often in pain, and another a potent estrogen, a treatment that had been used in prostate cancer treatment in previous years. Warfarin is a blood thinner that counteracts the effects of estrogen, such as an increased likelihood of blood clots.

While Nagourney's team has no plans to put together another PC-SPES formula, "we have redoubled our efforts to identify compounds for the treatment of prostate cancer," he says. "We anticipate we will have some such product available in the future."

About 189,000 new prostate cancer cases will be diagnosed in the United States this year, according to American Cancer Society estimates, and 30,200 men will die of the disease.

A Lesson To Be Learned

Meanwhile, Dr. Jeffrey D. White, director of the Office of Cancer Complementary & Alternative Medicine at the National Cancer Institute, calls the contamination a "lesson" for future dietary supplement research.

"Herbal research is complicated enough without having to deal with the added problem of potential product adulteration," he writes in an accompanying editorial in the journal.

Consumers Beware

Consumers should be aware that such problems can exist, White says. "Don't just expect these products should have undergone the same testing as [prescription] drugs." Since they are regulated as dietary supplements, they do not undergo the same rigorous review.

White praises the Nagourney study as "a very complete, careful analysis of several lots of the product, rather than looking at just a couple of recent lots."

Before deciding to use a dietary supplement for cancer treatment—or other health problems—patients should talk to their physician and get as much information as possible, White and Nagourney agree.

Always consult your physician for more information.

 Online Resources

American Association for Cancer Research

American Cancer Society

American Urological Association

National Cancer Institute

National Cancer Institute, Office of Cancer Complementary and Alternative Medicine

National Human Genome Research Institute

Nature Genetics

US Food and Drug Administration (FDA)

October 2002

Early Results Were Promising

Contamination Not Likely An Accident

A Lesson To Be Learned

Consumers Beware

Gene Mutation May Be Linked to Prostate Cancer

Online Resources

In Other Men's Health News:

Gene Mutation May Be Linked to Prostate Cancer 

Finding opens doors to potential treatments

Scientists have discovered another genetic clue that may eventually help physicians treat or even prevent prostate cancer.

The researchers have isolated a gene mutation they believe might play a role in the development of prostate cancer following infection of the gland. The gene, MSR1, a macrophage scavenger receptor, shows mutations in a significant percentage of men with prostate cancer, as well as in families where prostate cancer is hereditary, the researchers say.

MSR1 has previously been linked to the formation of arterial plaques that lead to heart disease, although these findings do not yet suggest a conclusive connection between prostate cancer and arterial plaques, the researchers say.

"We don't want to give people the impression this has immediate impact on how we manage prostate cancer," says William Isaacs, professor of urology and oncology at the Brady Urological Institute and Kimmel Cancer Center at Johns Hopkins University.

"However, this broadens our thinking about what may cause prostate cancer and how the body reacts and recognizes the process of prostate cancer formation," he says.

MSR1 helps white blood cells, called macrophages, clean up cellular debris from bacterial infections and damaged fats or lipids. Macrophage activity is known to increase in the early stages of prostate cancer, and the researchers suspected that some MSR1 mutations might inhibit the ability of macrophages to clean up properly after prostate infections, which produce inflammatory lesions that are often early markers of prostate cancer.

The novelty of this finding is that it is the first time this gene has ever been implicated in a cancer, Isaacs says.

In clinical practice, physicians already closely monitor prostate infection as a precursor to prostate cancer.

"Men often have infections in the prostate," says Dr. Timothy Thompson, professor of urology at Baylor College of Medicine in Houston. "However, the way the immune system reaction to infection develops into cancer is not straightforward," he says.

Thompson adds that in previous studies of macrophage activity in prostate cancer, macrophages sometimes seemed to be beneficial, engulfing prostate cancer cells to kill them. At other times, they seemed to assist cancer cells.

"If the macrophages persist in the prostate, it's probably because there are one or more cancer cells that are resistant. The cancer cells can then use factors secreted by the macrophages to survive and grow more virulent. If these interactions between macrophages and cancer cells are allowed to persist, they could set the stage for cancer," Thompson says.

The new findings were the result of collaborative efforts by researchers from Johns Hopkins University, Wake Forest University, and the National Human Genome Research Institute.

The study was published online yesterday in the journal Nature Genetics.

Isaacs notes that the current research looked only at men of African and European descent, leaving open future inquiry into Hispanics, Asians, and other populations.

Always consult your physician for more information.