Cancer Complementary and Alternative Medicine: Q & A

Complementary and Alternative Medicine in Cancer Treatment:
Questions and Answers



  • Complementary and alternative medicine is a group of diverse medical and health care systems, practices, and products that are not presently considered to be part of conventional medicine.
  • It is important that the same scientific evaluation that is used to assess conventional approaches be used to evaluate CAM therapies.
  • The National Cancer Institute and the National Center for Complementary and Alternative Medicine are sponsoring or cosponsoring various clinical trials to study CAM therapies for cancer.
  • It is important that patients inform all of their health care providers about any therapies they are currently using or considering. This is to help ensure a safe and coordinated course of care.
  1. What is complementary and alternative medicine?
  2. Complementary and alternative medicine, as defined by the National Center for Complementary and Alternative Medicine, is a group of diverse medical and health care systems, practices, and products that are not presently considered to be part of conventional medicine. Complementary medicine is used together with conventional medicine. Alternative medicine is used in place of conventional medicine. Conventional medicine is medicine as practiced by holders of M.D. or D.O. degrees and by their allied health professionals, such as physical therapists, psychologists, and registered nurses. Other terms for conventional medicine include allopathy; Western, mainstream, orthodox, and regular medicine; and biomedicine. Some conventional medical practitioners are also practitioners of CAM.

    This fact sheet answers some frequently asked questions about the use of CAM therapies among the general public, and about how CAM approaches are evaluated, and suggests sources for further information.

  3. Are complementary and alternative therapies widely used?
  4. The results of studies of CAM use have been inconsistent. One large-scale study published in the November 11, 1998, issue of the Journal of the American Medical Association found that CAM use among the general public increased from 33.8 percent in 1990 to 42.1 percent in 1997. However, an analysis of data from the 1999 National Health Interview Survey indicated that only 28.9 percent of U.S. adults had used at least one CAM therapy in the past year. These results were published in the journal Medical Care in 2002.

    Several surveys of CAM use by cancer patients have been conducted with small numbers of patients. One study published in the February 2000 issue of the journal Cancer reported that 37 percent of 46 patients with prostate cancer used one or more CAM therapies as part of their cancer treatment. These therapies included herbal remedies, vitamins, and special diets.

    A larger study of CAM use in patients with different types of cancer was published in the July 2000 issue of the Journal of Clinical Oncology. This study found that 69 percent of 453 cancer patients had used at least one CAM therapy as part of their cancer treatment. Additional information about CAM use among cancer patients can be found in a review article published in Seminars in Oncology in December 2002.

  5. How are CAM approaches evaluated?
  6. It is important that the same rigorous scientific evaluation used to assess conventional approaches be used to evaluate CAM therapies. The National Cancer Institute and NCCAM are funding a number of clinical trials at medical centers to evaluate CAM therapies for cancer.

    Conventional approaches to cancer treatment have generally been studied for safety and effectiveness through a rigorous scientific process that includes clinical trials with large numbers of patients. Less is known about the safety and effectiveness of complementary and alternative methods. Some CAM therapies have undergone rigorous evaluation. A small number of CAM therapies originally considered to be purely alternative approaches are finding a place in cancer treatment—not as cures, but as complementary therapies that may help patients feel better and recover faster. One example is acupuncture. According to a panel of experts at a National Institutes of Health Consensus Conference in November 1997, acupuncture has been found to be effective in the management of chemotherapy-associated nausea and vomiting and in controlling pain associated with surgery. In contrast, some approaches, such as the use of laetrile, have been studied and found ineffective or potentially harmful.

  7. What is the Best Case Series Program?
  8. The Best Case Series Program, which was started by the NCI in 1991, is one way CAM approaches that are being used in practice are being evaluated. The program is overseen by the NCI’s Office of Cancer Complementary and Alternative Medicine. Health care professionals who offer CAM services submit their patients’ medical records and related materials to OCCAM. OCCAM conducts a critical review of the materials and develops followup research strategies for approaches that have therapeutic potential.

  9. Are the NCI and NCCAM sponsoring clinical trials in complementary and alternative medicine?
  10. The NCI and NCCAM are currently sponsoring or cosponsoring various clinical trials to study complementary and alternative treatments for cancer. Some of these trials study the effects of complementary approaches used in addition to conventional treatments, while others compare alternative therapies with conventional treatments. Current trials include the following:

    Patients who are interested in taking part in these or any clinical trials should talk with their doctor.

    The NCI, NCCAM, and OCCAM clinical trials databases offer patients, family members, and health professionals information about research studies that use CAM. Clinical trials can be found by searching:

  11. What should patients do when using or considering complementary and alternative therapies?
  12. Cancer patients using or considering complementary or alternative therapy should discuss this decision with their doctor or nurse, as they would any therapeutic approach. Some complementary and alternative therapies may interfere with standard treatment or may be harmful when used with conventional treatment. It is also a good idea to become informed about the therapy, including whether the results of scientific studies support the claims that are made for it. Some resources for this information are provided in Question 8.

  13. When considering complementary and alternative therapies, what questions should patients ask their health care providers?

  14. Further information on evaluating CAM therapies and practitioners is available from NCCAM.

  15. What Federal agencies can provide more information about CAM therapies?
  16. Patients, their families, and their health care providers can learn about CAM therapies from the following Government agencies and resources:

    NCCAM is the Federal Government’s lead agency for scientific research on CAM. NCCAM is dedicated to exploring complementary and alternative healing practices in the context of rigorous science, training CAM researchers, and disseminating authoritative information to the public and professionals.

    The NCCAM Clearinghouse provides information on NCCAM and on CAM, including fact sheets, other publications, and searches of Federal databases of scientific and medical literature. Publications include:

    • “Are You Considering Using Complementary and Alternative Medicine?”
    • “Selecting a Complementary and Alternative Medicine Practitioner”
    • “Consumer Financial Issues in Complementary and Alternative Medicine”

    The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.

    NCCAM Clearinghouse
    Post Office Box 7923
    Gaithersburg, MD 20898–7923
    Toll-free in the United States: 1–888–644–6226
    International: 301–519–3153
    Callers with TTY equipment: 1–866–464–3615
    Fax: 1–866–464-3616
    Fax-on-Demand service: 1–888–644–6226
    Web site:

    The NCI’s Office of Cancer Complementary and Alternative Medicine coordinates the activities of the NCI in the area of complementary and alternative medicine. OCCAM supports CAM cancer research and provides information about cancer-related CAM to health providers and the general public via on the Internet.

    NCI’s PDQ, a comprehensive cancer information database, contains peer-reviewed summaries of the latest information about the use of CAM in the treatment of cancer. Each summary contains background information about the specific treatment, a brief history of its development, information about relevant research studies, and a glossary of scientific and medical terms. CAM summaries can be accessed at on the Internet

    The Food and Drug Administration regulates drugs and medical devices to ensure that they are safe and effective. This agency provides a number of publications for consumers, including information about dietary supplements.

    Food and Drug Administration
    5600 Fishers Lane
    Rockville, MD 20857
    Telephone: 1–888–463–6332
    Web site:
    FDA’s Dietary Supplements Web page:

    The Federal Trade Commission enforces consumer protection laws and offers publications to guide consumers. The FTC also collects information about fraudulent claims.

    Consumer Response Center
    Federal Trade Commission
    Washington, DC 20580
    Telephone: 1–877–FTC–HELP
    Callers with TTY equipment: 202–326–2502
    Web site:

    CAM on PubMed, a database accessible via the Internet, was developed jointly by NCCAM and the NIH National Library of Medicine. It contains bibliographic citations to articles in scientifically based, peer-reviewed journals on CAM. These citations are a subset of the NLM’s PubMed system, which contains over 11 million journal citations from the MEDLINE database and additional life science journals important to health researchers, practitioners, and consumers. CAM on PubMed also displays links to many publisher Web sites, which may offer the full text of articles. To access CAM on PubMed, go to on the Internet.


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    Eisenberg DM, Davis RB, Ettner SL, et al. Trends in alternative medicine use in the United States, 1990–1997. Journal of the American Medical Association 1998; 280:1569–1575.

    Kao GD, Devine P. Use of complementary health practices by prostate carcinoma patients undergoing radiation therapy. Cancer 2000; 88:615–619.

    Nelson W. Alternative cancer treatments. Highlights in Oncology Practice 1998; 15:85–93.

    Ni H, Simile C, Hardy AM. Utilization of complementary and alternative medicine by United States adults: Results from the 1999 National Health Interview Survey. Medical Care 2002; 40:353–358.

    Richardson MA, Sanders T, Palmer JL, Greisinger A, Singletary SE. Complementary/alternative medicine use in a comprehensive cancer center and the implications for oncology. Journal of Clinical Oncology 2000; 18:2505–2514.

    Richardson MA, Straus SE. Complementary and alternative medicine: Opportunities and challenges for cancer management and research. Seminars in Oncology 2002, 29: 531–545.

    Sparber A, Bauer L, Curt G, et al. Use of complementary medicine by adult patients participating in cancer clinical trials. Oncology Nursing Forum 2000; 27:623–630.

    White JD. Complementary, alternative, and unproven methods of cancer treatment. In: DeVita, Hellman, Rosenberg, editors. Cancer: Principles and Practice of Oncology. 6th edition. Philadelphia: Lippincott Williams & Wilkins, 2001. 3147–3157.

    This fact sheet is a joint effort of the National Cancer Institute and the National Center for Complementary and Alternative Medicine.