Complementary and alternative medicine are umbrella terms generally used to describe any method that is not considered standard practice to diagnose or treat illness or disease. Although often used together, it is important to distinguish between the two methods. Complementary medicine is used in addition to conventional medicine. Alternative medicine is used instead of conventional medicine. These two very different medical approaches are often grouped under a single heading – complementary and alternative medicine (CAM).

Various complementary therapies have been touted for their role in cancer prevention, treatment and the reduction of symptoms and side effects. In some cases, the benefits of complementary medicine may have been demonstrated, to one degree or another, in clinical tests. Therapies that are considered alternative to conventional medicine have not been tested in scientific studies. They are not supported by any objective scientific evidence.

In both complementary and alternative medicine, patients should be aware that the U.S. Food and Drug Administration (FDA) does not regulate or ensure the safety of many CAM-related products.

It is vital for patients to consult their physician before adding CAM to their treatment regimen. In some cases, these therapies may reduce their ability to fight cancer, by interfering with or delaying conventional, proven treatments.

The National Center for Complementary and Alternative Medicine (NCCAM) has established five complementary and alternative medicine categories. They are alternative medical systems, mind-body interventions, biologically-based therapies, manipulative and body-based methods, and energy therapies.