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Complementary and Alternative Medicine

Complementary and alternative medicine (CAM) is the term for medical products and practices that are not part of standard medical care. 

  • Standard medical care is medicine that is practiced by holders of M.D. (medical doctor) or D.O. (doctor of osteopathy) degrees. It is also practiced by other health professionals, such as physical therapists, physician assistants, psychologists, and registered nurses. Standard medicine may also be called allopathic, Western, mainstream, orthodox, regular medicine, and biomedicine. Some standard medical practitioners are also called practitioners of CAM.
  • Complementary medicine is used along with standard medical treatments. One example is using acupuncture to help with side effects of cancer treatment.
  • Alternative medicine is used in place of standard medical treatments. One example is using a special diet to treat cancer instead of a method that an oncologist suggests.
  • Integrative medicine is a total approach to care that involves the patient's mind, body, and spirit. It combines standard medicine with the CAM practices that have shown the most promise. 

NCI provides evidence-based PDQ information for many CAM therapies in both patient and health professional formats.

Are CAM approaches safe?

CAM therapies need to be evaluated with the same long and careful research process used to evaluate standard treatments. Standard cancer treatments have generally been studied for safety and effectiveness through an intense scientific process that includes clinical trials with large numbers of patients. Less is known about the safety and effectiveness of many CAM therapies. Research of CAM therapies has been slower for a number of reasons:

  • Time and funding issues
  • Problems finding institutions and cancer researchers to work with on the studies
  • Regulatory issues

Some CAM therapies have undergone careful evaluation, while others have been found ineffective or possibly harmful.

Natural Does Not Mean Safe

Dietary supplements such as herbs and vitamins may affect how well other medicines work in your body. For example, the herb St. John's wort, which some people use for depression, may cause certain anticancer drugs not to work as well as they should.

Herbal supplements can act like drugs in your body. They may be harmful when taken by themselves, with other substances, or in large doses. For example, some studies have shown that kava, an herb that has been used to help with stress and anxiety, may cause liver damage.

Vitamins can also take strong action in your body. For example, high doses of vitamins, even vitamin C, may affect how chemotherapy and radiation work. Too much of any vitamin is not safe, even in a healthy person.

Tell your doctor if you're taking any dietary supplements, no matter how safe you think they are. This is very important. Even though there are ads or claims that something has been used for years, they do not prove that it's safe or effective.

Supplements do not have to be approved by the Federal Government before being sold to the public. Also, a prescription is not needed to buy them. Therefore, it's up to consumers to decide what is best for them. 

NCI and the National Center for Complementary and Integrative Health (NCCIH) are currently sponsoring or cosponsoring various clinical trials. Some study the effects of complementary approaches used in addition to conventional treatments, and some compare alternative therapies with conventional treatments. Find all cancer CAM clinical trials.

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Dr. Jeffrey D. White, OCCAM Director, explains the use of complementary and alternative medicine in cancer.

What Should Patients Do When Using or Considering CAM Therapies?

Cancer patients using or considering complementary or alternative therapy should talk with their doctor or nurse. Some therapies may interfere with standard treatment or even be harmful. It is also a good idea to learn whether the therapy has been proven to do what it claims to do.

To find a CAM practitioner, ask your doctor or nurse to suggest someone. Or ask if someone at your cancer center, such as a social worker or physical therapist can help you. Choosing a practitioner should be done with care.

Patients, their families, and their health care providers can learn about CAM therapies and practitioners from the following government agencies:

  • Updated: April 10, 2015