Although complementary and alternative medicine (CAM) has been used for centuries, the formal study about the safety and effectiveness of individual therapies is relatively new. Today, cancer centers and government organizations are researching the safety and effectiveness of different CAM treatments by conducting clinical trials (research studies involving people).
Clinical trials help researchers understand the effectiveness of CAM in treating cancer and/or improving a person’s quality of life. During a clinical trial , a specific complementary or alternative therapy goes through a rigorous scientific process to determine whether it is beneficial, not beneficial, or potentially harmful.
Clinical trials have found that certain complementary approaches can help people living with cancer when used with conventional types of cancer treatment . In fact, some complementary therapies are especially helpful in relieving symptoms and side effects of cancer treatments. For example, acupuncture has been proven to relieve pain , a common symptom among people living with cancer. It also has been shown to reduce nausea and vomiting  caused by chemotherapy.
Clinical trials have also proven that alternative approaches have no benefit for people with cancer. For instance, a large study of people with lung cancer showed that giving shark cartilage extract with the standard cancer treatment did not increase survival . At this time, there are no valid alternatives to conventional cancer therapies.
The safety of CAM is especially important for people with cancer because both complementary and alternative therapies can interact with existing cancer treatments. For example, the herb known as St. John’s wort interferes with various chemotherapies, making these drugs more toxic or less effective.
Participating in a CAM clinical trial
People with cancer who are interested in participating in a clinical trial for CAM should consider the following tips:
- Talk with your doctor about which clinical trials might be appropriate for you.
- Find out the purpose of the trial and what is being studied. A study about CAM and cancer may be done to prevent cancer, to find a treatment for cancer, or to see if an intervention (such as yoga or art therapy) improves a person’s quality of life. These are all important goals, so it is important to know why the study is being done.
- Learn about the informed consent  process. During informed consent, the doctor should list all of your possible treatment options, how CAM will be used in the study, the risks and benefits of the CAM approach being tested, the necessary treatments, tests and/or procedures you will receive, and how the treatment through the clinical trial differs from the standard treatment. The doctor should also explain your option to withdrawal from the clinical trial at any time.
- Discuss all CAM treatments or approaches with your doctor, especially since some therapies may interfere with other medications or cancer treatments, or may have other side effects.
Finding a CAM clinical trial
Clinical trials for CAM can be found by asking a member of your health care team or searching online listings of clinical trials . Search for trials using keywords such as “complementary medicine” or the name of a particular CAM therapy. The National Cancer Institute's Office of Cancer Complementary and Alternative Medicine  (OCCAM) and the National Center for Complementary and Alternative Medicine  (NCCAM) provide listings of current clinical trials.