"Given the number of patients combining vitamins and herbs with conventional treatment, the oncology community must improve patient-provider communication, offer reliable information to patients, and initiate research to determine possible drug-herb-vitamin interactions," study authors write.

Mary Ann Richardson, DrPH, of the National Center for Complementary and Alternative Medicine in Bethesda, Md., and colleagues analyzed information from questionnaires filled out by 453 patients at eight M.D. Anderson Cancer Center outpatient cancer clinics in Houston between December 1997 and June 1998.

The researchers found 99.3 percent of cancer patients responding had heard of some form of alternative and complementary therapy, and 83.3 percent of those had used at least one form of those therapies. Most used alternative or complementary therapy in combination with conventional therapy recommended by their doctors.

More than 80 percent of patients who had heard of complementary and alternative therapies used some form of spiritual practice, such as prayer. About 63 percent had used vitamins or herbs, and 60 percent used movement or physical therapies. About 41 percent used psychotherapy; about 32 percent used a special diet; and 10 percent used other complementary and alternative methods.

The study showed most who used these therapies would prefer to get information about them from their doctors but didn't feel comfortable discussing the subject. The researchers say doctors should encourage patients to discuss use of complementary and alternative medicine, so patients can get reliable information from sources they trust.

An American Cancer Society (ACS) expert agrees. "It's important that physicians listen and not judge patients so patients feel comfortable sharing their ideas on complementary and alternative medicine use. Then doctors can help them sort out the useful complementary and alternative therapies that can help them from those that are useless or potentially harmful," says David S. Rosenthal, MD, professor of medicine at Harvard Medical School and head of the ACS advisory group on complementary and alternative medicine.

Rosenthal also endorses the researchers' call for more education about complementary and alternative methods for doctors. "Many times, patients have researched the field; they've gathered information about CAM [complementary and alternative medicine] therapies. So we need to be sure that we as physicians have all of the education and information we need to be able to respond responsibly to our patients."

Rosenthal says positive changes already are taking place. "More and more doctors are using CAM, learning more about CAM, and increasing numbers of cancer centers are integrating use of CAM and conventional medicine. Many doctors are learning from evidence-based outreach programs offered by those centers," he adds. "And the National Institutes of Health has begun training post-grad oncology fellows, making them CAM fellows."

"Quality information on CAM is now available for both doctors and patients at Web sites of reputable organizations like ACS and the National Institutes of Health," he adds.

In August, the American Cancer Society's Guide to Complementary and Alternative Cancer Methods will be published. This comprehensive resource guide will feature hundreds of entries covering a broad range of methods. Each entry was reviewed by experts.

Rosenthal says the increase in information and education represents important progress. "Yet there is still much, much more to be done making certain that accurate information on CAM is available both to physicians and to patients. With CAM use continuing to grow in popularity, it is progress that we in the medical community really must continue to make," he says.