This complementary and alternative medicine (CAM) information summary provides an overview of the use of mistletoe as a treatment for cancer. The summary includes a brief history of mistletoe research, the results of clinical trials, and possible side effects of mistletoe use.

This summary contains the following key information:

• Mistletoe is a semiparasitic plant that has been used for centuries to treat numerous human ailments.
• Mistletoe is used mainly in Europe, where a variety of different extracts are manufactured and marketed as injectable prescription drugs. These injectable drugs are not available commercially in the United States and are not approved as a cancer treatment.
• Although mistletoe plants and berries are considered poisonous to humans, few serious side effects have been associated with mistletoe extract use.
• The use of mistletoe as a treatment for cancer has been investigated in clinical studies. Reports of improved survival and/or quality of life have been common, but nearly all of the studies had major weaknesses that raise doubts about the reliability of the findings.
• At present, the use of mistletoe cannot be recommended outside the context of well-designed clinical trials. Such trials will be valuable to determine more clearly whether mistletoe can be useful in the treatment of specific subsets of cancer patients.

Many of the medical and scientific terms used in this summary are hypertext linked (at first use in each section) to the NCI Dictionary ¹, which is oriented toward nonexperts. When a linked term is clicked, a definition will appear in a separate window. All linked terms and their corresponding definitions will appear in a glossary in the printable version of the summary.

Reference citations in some PDQ CAM information summaries may include links to external Web sites that are operated by individuals or organizations for the purpose of marketing or advocating the use of specific treatments or products. These reference citations are included for informational purposes only. Their inclusion should not be viewed as an endorsement of the content of the Web sites, or of any treatment or product, by the PDQ Cancer CAM Editorial Board or the National Cancer Institute (NCI).

Glossary Terms

A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.

A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called a clinical trial.

A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called a clinical study.

CAM. Forms of treatment that are used in addition to (complementary) or instead of (alternative) standard treatments. These practices generally are not considered standard medical approaches. Standard treatments go through a long and careful research process to prove they are safe and effective, but less is known about most types of CAM. CAM may include dietary supplements, megadose vitamins, herbal preparations, special teas, acupuncture, massage therapy, magnet therapy, spiritual healing, and meditation. Also called CAM.

Use of a syringe and needle to push fluids or drugs into the body; often called a "shot."

A semiparasitic plant that grows on some types of trees. Mistletoe extracts are being studied as treatments for cancer.

The National Cancer Institute, part of the National Institutes of Health of the United States Department of Health and Human Services, is the Federal Government's principal agency for cancer research. The National Cancer Institute conducts, coordinates, and funds cancer research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. Access the National Cancer Institute Web site at http://www.cancer.gov. Also called NCI.

Having to do with or being a parasite (an animal or plant that gets nutrients by living on or in an organism of another species).

PDQ is an online database developed and maintained by the National Cancer Institute. Designed to make the most current, credible, and accurate cancer information available to health professionals and the public, PDQ contains peer-reviewed summaries on cancer treatment, screening, prevention, genetics, complementary and alternative medicine, and supportive care; a registry of cancer clinical trials from around the world; and directories of physicians, professionals who provide genetics services, and organizations that provide cancer care. Most of this information, and more specific information about PDQ, can be found on the NCI's Web site at http://www.cancer.gov/cancertopics/pdq. Also called Physician Data Query.

The overall enjoyment of life. Many clinical trials assess the effects of cancer and its treatment on the quality of life. These studies measure aspects of an individual’s sense of well-being and ability to carry out various activities.

A problem that occurs when treatment affects healthy tissues or organs. Some common side effects of cancer treatment are fatigue, pain, nausea, vomiting, decreased blood cell counts, hair loss, and mouth sores.