80% of cancer patients use some form of complementary or alternative therapies

Plug the terms "alternative" and "cancer" into Google and the Internet search engine returns a list of 3.27 million - yes, million - sites with information both credible and questionable about nontraditional treatments for cancer. What's a cancer patient to make of such a vast array of options?

This "vast array" is known collectively as complementary and alternative medicine, or CAM. And the issue of how patients find information about CAM therapies is important, experts say, because not all are created equal. While some can be genuinely helpful to patients in treatment or remission, others are outright dangerous. Still others are too poorly studied to tell. Nevertheless, huge numbers of cancer patients use these therapies.

"I would guess that over 80% of cancer patients use … some form of complementary or alternative therapies," says Barrie Cassileth, PhD, chief of the Integrative Medicine Center at Memorial Sloan-Kettering Cancer Center in New York. "Patients can't distinguish which are good and which are harmful, and we've got to help them do that."

To that end, experts from around the country have collaborated to form the Society for Integrative Oncology. This new professional group is a joint effort of 3 major cancer centers with strong CAM programs -- Memorial Sloan-Kettering, MD Anderson Cancer Center in Houston, and Boston's Dana-Faber Cancer Institute -- as well as other cancer-related organizations, including the American Cancer Society. The new group holds its first conference in November.

The goal, says Cassileth, president of the Society for Integrative Oncology, is to promote high-level research of CAM and to get reliable information to doctors so they can guide their patients.

Some complementary therapies that patients use in conjunction with traditional cancer treatments - like chemotherapy, surgery, and radiation - can be very helpful, Cassileth said.

Acupuncture, for example, has been shown to be effective at reducing nerve pain, and is being tested as a remedy for hot flashes for women who can't take hormones (such as breast cancer patients). Mind-body therapies like meditation and hypnosis are being studied as ways to help control pain from medical procedures. Music therapy can help relieve depression in patients who are having stem cell transplants.

Doctors also need to know which therapies are bogus and potentially dangerous -- treatments typically considered "alternative" because patients may use them instead of scientifically studied treatments.

An article earlier this year in CA: A Cancer Journal for Clinicians (Vol. 54, No. 2: 110-118) reviewed the evidence for nearly a dozen alternative cancer therapies and found that they don't hold up under scrutiny. Among the therapies investigated were high-dose vitamin C, laetrile (a compound made from apricot pits), shark cartilage supplements, and the Gerson regimen (a purportedly detoxifying combination of diet and coffee enemas).

Such therapies should no longer be considered "unproven," wrote author Andrew Vickers, PhD, of Memorial Sloan-Kettering. Rather, "it is time to assert that many alternative therapies have been 'disproven,' " he said.

Then there are treatments that fall somewhere in between the "proven" and the "disproven" -- many herbs, for instance.

"Botanicals have tremendous potential, but they need to be studied," Cassileth said. "At this point, patients only have access to what's available over the counter in the form of supplements, but those are not a good idea to try and should be avoided because of their potential to interact negatively with traditional therapy."

Research is being conducted, she said, but the process is slow.

Despite the unknowns, herbal supplements are extremely popular. As many as 6 in 10 cancer patients use these remedies, according to some studies.

And quite often they don't tell their doctors about it. In one study, for instance, out of MD Anderson, researchers found that nearly half of women being treated for breast and gynecologic cancers used some type of herbal or vitamin supplement (Journal of Clinical Oncology Vol. 22, No. 4: 671-677). Yet only about half of these women informed their doctor.

"We kind of knew that patients weren't telling physicians about CAM use," said co-researcher Judith Smith, PharmD, BCOP. "Most of them don't even consider it medication."

Indeed, less than a third of the women in the study thought of herbal products and vitamins as medication. Botanicals may be "natural," but they aren't necessarily risk-free.

A review by National Cancer Institute researchers published in the Journal of Clinical Oncology (Vol. 22, No. 12: 2489-2503) suggests that many of the most common herbal products have the potential to interact with cancer drugs -- either by diluting their effect so a patient is undertreated, or by amplifying it, resulting in the possibility of overdose.

The review focused on the top-selling herbal preparations in the US: garlic, ginkgo, echinacea, soy, saw palmetto, ginseng, St. John's wort, black cohosh, cranberry, valerian, milk thistle, evening primrose, kava, bilberry, and grape seed.

Much of this research has been performed in lab samples or in animals, lead author Alex Sparreboom, PhD, emphasized; evidence from human trials is scarce, so doctors don't know for certain that any of these products will react dangerously with cancer drugs.

Nevertheless, patients and doctors should use caution, experts say, and keep the lines of communication open.

Doctors should question cancer patients about CAM use and monitor them for unusual symptoms or reactions, said William Figg, PharmD, co-author of the herbal review.

"I think the best thing to do is to be aware that patients are likely taking [herbal supplements] and be aware they might not tell you about it," he said..

Sparreboom suggested doctors keep a list of potentially troublesome compounds, such as those noted in his review, to ask patients about.

Smith agreed that doctors need to take an active role in talking to patients about CAM. In her study, most of the women who didn't talk to their doctor about CAM use said it was because the doctor never asked about it.

But patients also must be forthcoming, Smith said, not just about CAM, but about all over-the-counter medications.

"I don't think the onus should totally be put on physicians, although they should be asking," she said. "Patients should be telling doctors everything they're taking and consulting with a physician before trying something new, particularly if they have other [conditions] like diabetes or high blood pressure."