The Christmastime tradition of hanging a sprig of mistletoe above the doorway originated in Greek folklore. Now, another use for the plant is becoming popular in the United States — complementary cancer therapy. Almost two years ago, the scientific and clinical review committees of the Kimmel Cancer Center at Thomas Jefferson University Hospital, Philadelphia, Pa., looked at available research on the use of mistletoe as a supportive treatment for cancer patients. They concluded that it was an acceptable supportive therapy for patients seeking such options. Ever since, the prescription-only medicine made from the extracts of the European mistletoe plant has been offered as part of care to cancer patients through Jefferson’s Center for Integrative Medicine. "I believe it is helpful, and I suggest it to my patients," says Steven Rosenzweig, MD, founding director of the center, which integrates complementary therapies into patient care to reduce symptoms and enhance quality of life. He is also principal investigator of a National Institutes of Health-funded clinical trial of mistletoe in lung cancer. Mistletoe therapy is not a new healthcare regimen. In fact, there is evidence that the Druids and ancient Greeks used mistletoe to treat a variety of disorders — from arthritis to rheumatism. Interest in mistletoe as an anticancer drug began in the early 1920s in Europe. Austrianborn Rudolf Steiner, the father of anthroposophical medicine — which focuses on treating the mind and spirit as well as the patient’s physical symptoms — was the first to suggest it for the treatment of tumors. Today in Europe, more than one-half of patients who are diagnosed with cancer use some form of mistletoe in their treatment. Marketed in Europe under the brand names Iscador, Eurixor, Helixor, Isorel, Vysorel, and ABNOBAviscum, mistletoe is the No. 1 prescribed cancer medicine in Germany. In the United States, Iscar is the only mistletoe product approved for distribution by the FDA in accordance with its requirements for homeopathic medicines. Hiscia Institute, a Swiss-based pharmaceutical company, manufactures Iscar, which is distributed worldwide by Weleda, Inc. A solution containing extracts from a select variety of mistletoe, Iscar is injected under the skin. A series of injections are administered for at least one year, and often for the duration of the patient’s life.

complementary

RADIOLOGY TODAY / DECEMBER 23, 2002

Mistletoe has been gaining substantial popularity in the United States. What’s happening at the Kimmel Cancer Center is occurring at a growing number of institutions. Michele Sanz, manager of the medical services division of Weleda, Inc. USA in Congers, N.Y., says Iscar has seen doubledigit growth since it was introduced to the United States in 1999. Interest was particularly strong in 2001 after actress Suzanne Somers revealed on Larry King Live that she has opted to treat her breast cancer with mistletoe. While the use of mistletoe is growing incredibly fast in America, it remains controversial. "It is still in the classification of an emerging therapy that hasn’t fully arrived here yet," says Larry Burk, Jr, MD, associate professor of clinical radiology and director of education, Duke University Health System’s Center for Integrative Medicine. "In North Carolina, it’s what we call ‘frontier medicine’ at this point because it is only used by one anthroposophical practitioner in our area." According to Burk, the American medical community tends to demand larger clinical trials than physicians in Europe, and most conventionally trained physicians want more evidence from well-designed studies before they start prescribing it. On its Web site, www.cancer.gov, which was last updated in May, the National Cancer Institute (NCI) says: "There is no evidence from well-designed clinical trials that mistletoe or any of its components are effective treatments for human cancer."
However, the NCI evaluated mistletoe’s effectiveness as a stand-alone therapy in cancer, which is not its role, ccording to Rosenzweig. Mistletoe has been the most extensively researched botanical medicine, and a clear safety record has been established, he says. "A recent literature review found 23 published controlled trials on mistletoe therapy with meaningful end points," Rosenzweig asserts. "Sixteen to 18 of these trials were randomized. All of them suffered from some type of methodological flaw; however, I would say that overall, the studies tend to show positive outcomes for survival and treatment response as far as quality of life and quality of life in relationship to chemotherapy." It is believed that the three components of mistletoe—lectins, alkaloids, and viscotoxins —are responsible for its biological effects, which include killing cancer cells and slowing tumor growth.

While the use of mistletoe is growing incredibly fast in America, it remains controversial. "It is still in the classification of an emerging therapy that hasn’t fully arrived here yet,"
says Larry Burk, Jr, MD, associate professor of clinical radiology and director of education, Duke University Health System’s Center for Integrative Medicine

While Rosenzweig is convinced of the benefits of mistletoe, he agrees that additional and better studies need to be conducted. "Because of the methodological issues that influence the quality of these studies, I believe this is a treatment that must be studied more extensively using the highest quality of scientific methodology and also addressing clinical outcomes," he says. Rosenzweig says he has found that the
oncologists with whom he has had contact "are generally open to the addition of mistletoe" to their patients’ treatment regime. Rosenzweig first became interested in anthroposophical medicine in 1989 when, after finishing his residency in emergency medicine, he and his wife took a trip to Europe. They went to Switzerland, where he happened upon an anthroposophical hospital. "I had not been aware that this kind of hospital existed," he says. "I spent two days going on rounds with the physicians and learning about caring for people in a way that adds natural medicines, massage, movement therapy, and a psycho-spiritual dimension. I was so impressed that I came back to the United States and began to study more about anthroposophical medicine." Mark Eisen, MD, who is in private practice in Chapel Hill, N.C., and is a past lecturer for the University of North Carolina School of Medicine program on integrative medicine, has
been using mistletoe for years as a treatment for many of his cancer patients. He, too, has found a marked improvement in the quality of life of patients who opt for mistletoe as part of or as a singular treatment for their cancer. "Patients almost universally say that as a result of the injections, they have more energy, sleep better, have improved appetites, and feel warmer." Eisen, who was introduced to
complementary medicines in 1975 and who studied in Germany from 1985 to 1989, says mistletoe also seems to reduce tumor pain. He has found it to be effective for a variety of cancers, but particularly so as part of treatment for patients with breast, bowel, prostate, and some lung cancers. Eisen says some patients seek him out because they know he prescribes mistletoe, while other times he is the one
who suggests its use to others as part of their cancer treatment. A family practitioner, Eisen coordinates his cancer patient treatments with local oncologists and radiologists. Mistletoe, he says, "may not save cancer patients’ lives just as conventional therapies may not, but it certainly can be effective for prolonging life and helping patients have a better quality of life."

— Beth W. Orenstein is a contributing writer who lives in Northampton, Pa.