There could be something to prostate supplement
Herbs for prostate cancer? Doctors in this country have gone from ridiculing to recommending to once again rejecting the idea, all in a few years. But the debate over using natural therapy to treat this difficult disease is not over.
Earlier this year, thousands of American men battling prostate cancer were stunned when the dietary supplement PC Spes was taken off the market. Studies have shown that the blend of eight herbs slows tumor growth and prolongs life in men with advanced cancer who have stopped responding to conventional therapies.
In February, however, California health officials discovered that batches of PC Spes were contaminated with warfarin, a blood thinner. The news got worse. Subsequent lab testing of PC Spes turned up the presence of DES, an estrogen-like drug formerly used to treat prostate cancer. (DES can cause side effects such as blood clots and breast enlargement, which is why it’s rarely used today.) Officials at BotanicLab, the Brea company that marketed PC Spes, have said they aren’t sure how the pills became tainted. Facing lawsuits and a public relations fiasco, BotanicLab went out of business in June. Just before the company shut down, a headline in the Wall Street Journal proclaimed “Prostate-Cancer Herbs Gone for Good.”
Don’t be so sure. Natural Approaches to Prostate Cancer, a nonprofit group in Portland, Ore., hopes to introduce a supplement containing the same combination of herbs in PC Spes by early next year. Already, copycat supplements with sound-alike names and similar ingredients are for sale on the Internet.
And scientists remain intrigued by PC Spes. Many men who used the supplement, and some physicians who recommended it for patients for whom standard treatments had failed, suspect that the herbal preparation was merely a cheap drug -- DES -- mixed with herbs and sold at a hefty price.
As the controversy waned, new information emerged. For example, researchers at UC San Francisco and Harvard University were conducting a clinical trial comparing men with prostate cancer who were taking PC Spes or DES. The researchers stopped the trial after California officials discovered the tainted batches of PC Spes. However, preliminary results from that study showed that men receiving PC Spes were faring better than those taking DES. PSA levels (a measure of prostate tumor growth) had dropped in 45% of the men using herbs, contrasted with 21% of the DES men.
The fact that the men taking PC Spes had more than twice the response suggests that the herbs may have cancer-fighting properties independent of any possible benefits conferred by traces of DES, says Dr. Jeffrey White, director of the office of cancer complementary and alternative medicine at the National Cancer Institute. White says it’s too soon to assume that PC Spes was largely DES in disguise.
Research led by Dr. Phillip Koeffler, chief of hematology and oncology at Cedars-Sinai Medical Center in Los Angeles and a scientist at UCLA’s Jonsson Cancer Center, has shown that components found in a purified version of PC Spes not only disable hormones that feed the growth of prostate cancer, but also cause cancer cells to commit suicide.
Koeffler theorized that if something in PC Spes combats prostate cancer cells, then it was worth trying the herbs against other cancers. Last month, his team published a paper in the journal Cancer Research showing that a substance in PC Spes called baicalin may halt colon cancer. Specially bred cancer-prone mice that were fed baicalin developed half as many colon polyps (small formations in the intestines that often develop into malignant tumors) as mice that didn’t eat baicalin. Koeffler’s team also has shown in test tube studies that PC Spes may fight lung cancer and leukemia.
PC Spes probably wouldn’t show such diverse cancer-fighting potential if its only active ingredient was the estrogen-like DES, says Koeffler. “I’m 99% sure that estrogen doesn’t have any effect on leukemia. I’m fairly sure it has no effect on lung cancer. And it probably doesn’t have any effect on colon cancer,” he says. “I doubt the anti-tumor effects we’ve noticed are due to that contaminant.”
Other observers are less convinced PC Spes has much effect on cancer. “Baicalin works,” says Dr. Robert Nagourney of Rational Therapeutics in Long Beach. The question -- still unanswered -- is whether PC Spes contains anywhere near the amount of baicalin needed to produce a therapeutic effect.
Nagourney coauthored a study that appeared in last month’s Journal of the National Cancer Institute in which he and colleagues analyzed the content of several batches of PC Spes. They found that batches laced with high amounts of DES were far more effective in killing cancer cells than batches that had little or no DES. (The study also turned up more traces of warfarin, as well as the anti-inflammatory drug indomethacin.)
In August, the National Center for Complementary and Alternative Medicine announced that three lab studies of PC Spes that it was funding, but had suspended after the controversy, could resume.
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Massachusetts freelance writer Timothy Gower can be reached by e-mail at tgower@attbi.com. The Healthy Man runs the second Monday of the month.
