The Promise of Plants
By Julia Sommerfeld
Greg Palamountain had just about run out of available treatment options for his advanced prostate
cancer. After undergoing prostate-removal surgery, radiation treatments and hormone therapy, the
disease was still progressing. So, feeling like he had nothing to lose, in October 1998, the insurance
broker from Piedmont, Calif., entered a clinical trial of an ancient Chinese herbal remedy. Today, at
57, he credits the formula, called PC-SPES, for adding years to his life.
"After I had read all the literature on it, I decided it was something at least worth trying," Palamountain remembers. "I said, 'If it doesn't work, it doesn't work, but let's give it a shot.'"
So he embarked on a two-year trial of PC-SPES, an over-the-counter dietary supplement that contains a combination of eight herbs including chrysanthemum, licorice and saw palmetto.
The study, conducted at the University of California at San Francisco, is part of a push for science to catch up with consumers who have already made herbal supplements a multi-billion dollar industry. After centuries of use, traditional herbal remedies have only recently begun to be put through rigorous scientific testing.
"We are currently trying to interface herbs with medical science," says Robin DiPasquale, a naturopathic physician and chair of botanical medicine at Bastyr University, a school of natural health sciences in Kenmore, Wa. "Their standard is scientific research so we are having to apply that standard to herbs to validate them in the medical community."
And while science is stamping some dietary supplements as snake oil such as shark cartilage, which is promoted as a cancer-fighter but so far has been shown to lack bite other herbal remedies, such as PC-SPES, are showing positive results in clinical trials published in major peer-reviewed scientific journals, a rite of passage for acceptance into mainstream medicine.
BATTLING PROSTATE CANCER
Like most research on herbal supplements, the UCSF study on PC-SPES (PC stands for prostate cancer and SPES is Latin for hope) was a response to thousands of patients using a product that their doctors were completely in the dark about.
"We became interested in PC-SPES when patients started coming in saying, 'Hey doc, look at how great this is working,'" says the study's lead researcher Dr. Eric Small, an associate professor of medicine and urology. "We felt very strongly that it needed to be studied."
So Small and colleagues at the UCSF Comprehensive Cancer Center treated 70 prostate cancer patients, including Palamountain, with nine capsules of PC-SPES daily. Half had hormone-sensitive disease, which means they had never before received hormone therapy; the other half had been treated with hormones and had developed hormone resistance, meaning their cancer was spreading despite suppressed testosterone levels.
Among the hormone-sensitive patients, 100 percent had a significant response to PC-SPES their levels of prostate-specific antigen (PSA), a protein produced by the prostate gland that is a key indicator of tumor growth, dropped and stayed down for a year on average. In over half of these patients, the PSA dropped to an undetectable level, according to findings published last November in the Journal of Clinical Oncology.
Though such results were impressive, they weren't completely surprising because researchers had already suspected that the herb mix contained some natural estrogen-like compounds that would probably work like standard hormone therapy on hormone-sensitive patients decreasing their testosterone levels, and in turn slowing down tumor growth.
The real test was in the hormone-resistant patients, like Palamountain, for whom standard hormone treatments weren't working. Among these patients, half saw their PSA level drop by 50 percent or more and stay down for an average of four months. Plus, some patients whose cancer had spread showed tumor regression in bone scans.
The results suggest that there may be more to the herb mix than just plant estrogens, that there may be some additional cancer-fighting activity, Small says.
Palamountain is among the success stories: His PSA went from a high of 78 to a low of 16. "Almost immediately my PSA went down, and for two years it stayed down," he says. This is particularly significant for Palamountain because without PC-SPES he likely would have already had to undergo chemotherapy, often the treatment of last resort for prostate cancer, a treatment the active outdoorsman wants to avoid as long as he can because of the potentially debilitating side effects.
"This is exactly the kind of patient to whom we recommend PC-SPES," Small notes.
After two years on PC-SPES, Palamountain's PSA started to rise again a few months ago. Now, it's at 51, and if it gets much higher he is going to start considering other treatments. He's interested in entering trials of more experimental cancer therapies. But even if he does eventually need to resort to the chemotherapy, he says he feels that PC-SPES has given him extra healthy time to spend with his family and do the things he loves.
"This is not a home run," Small says. "Even at its best it's not a cure-all, but it is one added weapon in our armamentarium."
Another recent study found results similar to Small's. Dr. Aaron Katz, an associate professor of urology at Columbia University College of Physicians and Surgeons, co-authored a study of PC-SPES in 69 prostate cancer patients in the Journal of Urology last October. Overall, 82 percent had a significant drop in PSA; and among the hormone-resistant patients, 74 percent had reduced PSA levels at six months.
"This is the first herbal compound that can kill cancer cells and reduce PSA even when traditional therapy has failed. I find that remarkable," Katz says.
Though there have been a handful of small studies and many anecdotal reports on PC-SPES, the studies by Katz and Small are the first to examine the herb mix in a large number of men.
"It definitely has activity in patients with advanced prostate cancer, even in some patients who have failed hormone therapy," says Dr. William Catalona, chief of urology at Washington University in St. Louis, who was not involved in the research.
Still, more studies are needed, experts say.
"There's promising research on PC-SPES in a select group of patients," says Dr. Durado Brooks, director of prostate cancer programs for the American Cancer Society. "But I think it's clear we need to do more research and find out where this drug might fit into the prostate cancer medicine cabinet."
NATURAL DOESN'T EQUAL RISK-FREE
As with many herbs, PC-SPES is not without a downside. Possible side effects include nipple tenderness, breast enlargement, decreased libido, impotence, diarrhea and leg cramps. The most serious risk is potentially fatal blood clots in the legs or lungs, a complication that has been reported in 3 percent to 5 percent of patients.
Palamountain says he feels good on PC-SPES. He regularly hunts, fishes and skis, and walks at least a mile a day. And though he has experienced some breast enlargement, the side effects have been tolerable.
"I'm able to deal with it fairly well because I look at the alternatives," he says. "I've gone two years now and hopefully I can go a little longer. The only thing that I have is breast enlargement...I just don't take my shirt off in the summer."
He says the biggest downside to PC-SPES is the cost because insurance companies don't cover it. He spends over $400 a month for the treatment.
"Unfortunately, now that the trial is over I have to pay for it myself and it's very expensive," he says.
Because of the side effects and a lack of long-term follow-up studies, most doctors says PC-SPES should only be used by prostate cancer patients who have not been helped by conventional therapy. But because it's available without a prescription, anyone can use or misuse it.
"I take more men off of it than I put on," Katz says. "Patients without prostate cancer come in and say theyre taking it to prevent the disease. But there's no evidence that it prevents prostate cancer. I tell them to get off of it."
Additionally, some men, like Charles Reinwald, a 75-year-old attorney from Scarsdale, N.Y., are using it as a first-line therapy for prostate cancer, often contrary to their doctor's recommendations.
Reinwald was diagnosed with advanced prostate cancer in December 1999. After hearing differing recommendations from multiple doctors, including hormone therapy, external beam radiation and the implantation of radioactive seeds into his prostate gland, he decided to try PC-SPES instead.
"I was concerned about the side effects of the conventional treatments, the treatments that were recommended to me," Reinwald says. "Weighing all the circumstances that were applicable to my specific case my age, my health, my life expectancy I decided I should try PC-SPES."
So far, the herb mix appears to be working for him. His PSA has dropped from 32 to 0, and he says the side effects minimal breast swelling and a reduction in libido have been acceptable. His oncologist, Dr. Abraham Mittelman, an associate professor of medicine and microbiology at New York Medical College in Valhalla, N.Y., has conducted some research showing anti-cancer activity for PC-SPES in animals, but he is not in favor of using it as a first-line therapy. He recommends it only for hormone-resistant patients who are running out of treatment options and hoping to postpone chemotherapy.
But Mittelman acknowledges that PC-SPES seems to be working for Reinwald. "Since his PSA is down and he's feeling good, we'll watch it for a period of time. And as long as it stays at this level, I will leave him alone," he says.
Reinwald says if his PSA started to rise he would reconsider his doctor's recommendations, but for now he's sticking with PC-SPES. "So far I would say this is the best choice," he says. "But you know I can't be sure of what the future holds. I just hope that it continues to do a good job for me."
MORE HERB TRIALS UNDERWAY
The government has taken notice of PC-SPES. In October, the National Center for Complementary and Alternative Medicine (NCCAM), part of the National Institutes of Health, granted funding for a study of the supplement at Johns Hopkins Center for Cancer Complementary Medicine in Baltimore. The study will be the first randomized, double-blind, placebo-controlled trial of PC-SPES, the "gold standard" for evaluating whether a treatment works.
NCCAM, which was created by the federal government to sponsor studies on alternative medicine, has yet to release results from any large-scale scientific studies of herbs. But the results of a major trial evaluating St. John's wort for the treatment of depression are expected to be available this spring, and other supplement studies are underway.
But a fair amount of knowledge about herbs has been around for many years, says Dipasquale of Bastyr University. She points out that many of our modern medicines are derived from plants for example, digoxin, which is used for heart failure, comes from the digitalis plant; and Taxol, a therapy for cancer prevention, comes from the yew tree.
"We do know quite a lot about the 10 or 20 most popular botanicals," says Gail Mahady, research assistant professor of pharmacogsy (study of the active ingredients in plants) at the University of Illinois in Chicago. "For example, we have significant clinical evidence for gingko for age-associated memory loss and Alzheimer's, and garlic for reducing cardiovascular risks. There's already a lot of science supporting the use of herbs."
Scientific studies also support saw palmetto for treating urinary symptoms of benign prostatic hyperplasia, ginger for easing nausea and feverfew for preventing migraines, among others.
Plus, there have been thousands of studies conducted abroad, mainly in Germany, that suggest a health benefit for more than 200 plant products. But according to Mahady, the research is of varying quality, "ranging from really poor to quite good," so more studies are needed to validate the results and identify potential safety concerns like drug-herb interactions.
"There was a lot of prejudice and narrow-mindedness about herbal products, but now science is validating that they can play a role in some diseases where traditional medicine hasn't been effective," says Gary Elmer, an associate professor of medicinal chemistry at the University of Washington School of Pharmacy in Seattle.
"I'm quite optimistic that more is going to be known about herbal products in the next few years."