Purpose of This PDQ Summary
Overview
General Information
History
Laboratory/Animal/Preclinical Studies

Essiac Flor•Essence The Individual Herbs of Essiac and Flor•Essence

Human/Clinical Studies

Essiac Flor•Essence

Adverse Effects
Overall Level of Evidence for Essiac and Flor•Essence
Changes to This Summary (03/20/2008)
More Information

Purpose of This PDQ Summary

This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about the use of Essiac as a treatment for cancer. This summary is reviewed regularly and updated as necessary by the PDQ Cancer Complementary and Alternative Medicine Editorial Board ¹.

Information about the following is included in this summary:

• A brief history of Essiac research.
• Possible side effects of Essiac use.

This summary is intended as a resource to inform and assist clinicians and other health professionals who care for cancer patients. It does not provide formal guidelines or recommendations for making health care decisions.

Some of the reference citations in the summary are accompanied by a level of evidence designation. These designations are intended to help the readers assess the strength of the evidence supporting the use of specific interventions or treatment strategies. The PDQ Cancer Complementary and Alternative Medicine Editorial Board uses a formal evidence ranking system ² in developing its level of evidence designations. These designations should not be used as a basis for reimbursement determinations.

This summary is also available in a patient version ³, which is written in less technical language.

Overview

This complementary and alternative medicine (CAM) information summary provides an overview of the use of Essiac and Flor•Essence, which are proprietary herbal tea mixtures, as treatments for patients with cancer. The summary includes a brief history of the development of Essiac and Flor•Essence; a review of laboratory, animal, and human studies; and possible side effects associated with Essiac and Flor•Essence use.

This summary contains the following key information:

• Essiac and Flor•Essence are herbal tea mixtures originally developed in Canada. There may be differences between Essiac and Flor•Essence in their mixture content and effects.
• These products are marketed worldwide as dietary supplements.
• Proponents have claimed that Essiac and Flor•Essence can help detoxify the body, strengthen the immune system, and fight cancer.
• Proponents of Essiac have claimed further that it can help relieve pain, improve quality of life, and reduce tumor size.
• Molecules with antioxidant, anti-inflammatory, anticancer, or immunostimulatory activity have been identified in the individual herbs in the Essiac and Flor•Essence formulas.
• No controlled data are available from human studies to suggest that Essiac or Flor•Essence can be effective in the treatment of patients with cancer.
• Some evidence suggests that Flor•Essence may increase tumor formation in an animal model of breast cancer.

Many of the medical and scientific terms used in the summary are hypertext linked (at first use in each section) to the NCI Dictionary ⁴, 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).

General Information

Essiac and Flor•Essence are proprietary herbal tea mixtures produced by different manufacturers. Essiac is reported to contain four herbs: burdock root (Arctium lappa L.), Indian rhubarb root (Rheum palmatum L., sometimes known as Turkish rhubarb), sheep sorrel (Rumex acetosella L.), and the inner bark of slippery elm (Ulmus fulva Michx. [synonym Ulmus rubra]).[1] Reviewed in [2-10] Flor•Essence is reported to contain the same four herbs as Essiac, plus four potentiating herbs: watercress (Nasturtium officinale R.Br.), blessed thistle (Cnicus benedictus L.), red clover (Trifolium pratense L.), and kelp (Laminaria digitata [Hudson] Lamx.).[11] Reviewed in [2-4,7]

The manufacturers of Essiac and Flor•Essence both claim they market the original herbal mixture promoted by the developer.[1,11] Although only one company manufactures Flor•Essence,[11] several companies produce and market Essiac-like products. Reviewed in [2,3,10] This summary contains information about the trademarked mixtures only and differentiates between the two products wherever possible. Essiac and Flor•Essence may vary in their mixture content and effects.[12]

Essiac and Flor•Essence are said to detoxify the body and strengthen the immune system.[1,11] Reviewed in [4,6,7,9] Proponents of Essiac claim further that it helps relieve pain, improves overall quality of life, may reduce tumor size, and may prolong the survival of patients with various types of cancer. Reviewed in [4,7,9] The individual herbs in the Essiac and Flor•Essence formulas have been shown to contain molecules that have anticancer, anti-inflammatory, antioxidant, or immunostimulatory activity (refer to the Laboratory/Animal/Preclinical Studies ⁵ section of this summary for more information). Reviewed in [2-4,9,13-16] It is said that the benefits of Essiac and Flor•Essence are dependent on the presence of the constituent herbs in the correct proportions. Reviewed in [2-4,9] In 2004, a mixture of the Essiac herbs showed a decreased proliferation of a prostate cancer cell line.[17] (Refer to the Laboratory/Animal/Preclinical Studies section of this summary for more information.)

Although the use of Essiac and Flor•Essence is generally associated with cancer treatment, both products have been used to treat other health conditions. Essiac has reportedly been used to control diabetes and to treat acquired immunodeficiency syndrome. Reviewed in [6] Flor•Essence has reportedly been studied in Russia as a treatment for chronic gastrointestinal diseases (i.e., esophagitis, gastritis, duodenitis, and colitis) and as a treatment for cirrhosis of the liver. Reviewed in [2] No controlled data have been published in the peer-reviewed scientific literature, however, to show the safety or the efficacy of Essiac or Flor•Essence in patients with cancer or these other health conditions (refer to the Human/Clinical Studies ⁶ section of this summary for more information).

Essiac and Flor•Essence are sold worldwide as health tonics or herbal dietary supplements.[1,11] Reviewed in [2-4,10] In the United States, health tonics and dietary supplements are regulated as foods, not drugs. Therefore, premarket evaluation and approval by the U.S. Food and Drug Administration (FDA) are not required, and specific disease treatment or prevention claims are not allowed. Because health tonics and dietary supplements are not formally inspected for manufacturing consistency, there may be considerable variation from lot to lot, and there is no guarantee that ingredients identified on product labels are present at all or are present in the specified amounts. The FDA has not approved the use of either Essiac or Flor•Essence for the treatment of patients with cancer or any other medical condition.

To conduct clinical drug research in the United States, researchers must file an Investigational New Drug (IND) application with the FDA. An IND application must also be made for clinical evaluation of dietary supplements as agents for the treatment or prevention of disease. The FDA’s IND process is confidential, and the existence of an IND application can be disclosed only by the applicants. To date, no investigator has announced filing an IND application to study either Essiac or Flor•Essence in the treatment of patients with cancer.

Essiac and Flor•Essence are administered orally in the form of herbal teas.[1,11] Reviewed in [4,6,8,9,18] Originally, an extract of one of the herbs (not specified) was administered to cancer patients by intramuscular injection at or near tumor sites, and the other herbs were administered orally as a tea. Reviewed in [4,8,9,18]

Only minimal information about dose and schedule of administration is freely available from the manufacturer of Essiac.[1] According to the manufacturer, the dose will vary, depending on the reason for ingestion; the manufacturer’s recommended schedules of administration assume a 12-week program of uninterrupted use.[1] Although Essiac is said to be safe for pets, no information is given about its safety in children.[1]

The manufacturer of Flor•Essence states that adults may consume from 30 to 360 mL (i.e., 1–12 fl oz) of Flor•Essence tea a day, depending on individual requirements, and that it may be used on an ongoing basis.[11] The manufacturer also suggests that Flor•Essence may be safely consumed by infants and children, but its use by pregnant women and nursing mothers is not recommended.[11] The promotion of mammary tumors observed in a rat model of breast cancer raises the theoretical concern that Flor•Essence may impact normal mammary ductal development during childhood, thereby raising concern about its use at this time.[19]

The manufacturers of Essiac and Flor•Essence both state these products can be used in conjunction with other cancer treatments.[1,11] Nonetheless, some proponents of Essiac have recommended that no additional anticancer therapy (such as chemotherapy or radiation therapy) be undertaken while patients are being treated with the mixture. Reviewed in [8] The purported rationale for this statement is that conventional anticancer treatments may alter immune system function and prevent Essiac from working effectively. Reviewed in [8] As indicated previously, no evidence has been reported in the peer-reviewed scientific literature to show that Essiac is an effective treatment for patients with cancer.

References

1. Essiac. Kirkland, Canada: Altramed Health Products, 2002. Available online. ⁷ Last accessed March 07, 2008. 
   
   
2. Tamayo C, Richardson MA, Diamond S, et al.: The chemistry and biological activity of herbs used in Flor-Essence herbal tonic and Essiac. Phytother Res 14 (1): 1-14, 2000.  [PUBMED Abstract]
   
   
3. Tamayo C: Essiac for cancer. Alternative Therapies in Women's Health 2 (3): 19-23, 2000. 
   
   
4. Kaegi E: Unconventional therapies for cancer: 1. Essiac. The Task Force on Alternative Therapies of the Canadian Breast Cancer Research Initiative. CMAJ 158 (7): 897-902, 1998.  [PUBMED Abstract]
   
   
5. Ernst E, Cassileth BR: How useful are unconventional cancer treatments? Eur J Cancer 35 (11): 1608-13, 1999.  [PUBMED Abstract]
   
   
6. Locock RA: Essiac. Can Pharm J 130: 18-9, 1997. 
   
   
7. Reviews of Therapies: Herbal/plant therapies: Essiac. Houston, Tex: M.D. Anderson Cancer Center, 2002. Available online. ⁸ Last accessed March 07, 2008. 
   
   
8. Herbal treatments. In: US Congress, Office of Technology Assessment.: Unconventional Cancer Treatments. Washington, DC: U.S. Government Printing Office, 1990. OTA-H-405, pp 71-5. Also available online. ⁹ Last accessed March 07, 2008. 
   
   
9. Essiac. Toronto, Canada: Canadian Breast Cancer Research Alliance, 1996. 
   
   
10. The History of Essiac & Rene Caisse, Canada's Cancer Nurse. Kirkland, Canada: Altramed Health Products, 2001. Available online. ¹⁰ Last accessed March 07, 2008. 
    
    
11. Flora Flor•Essence®. Burnaby, Canada: Flora Manufacturing & Distributing Ltd. Available online. ¹¹ Last accessed March 07, 2008. 
    
    
12. Cheung S, Lim KT, Tai J: Antioxidant and anti-inflammatory properties of ESSIAC and Flor-Essence. Oncol Rep 14 (5): 1345-50, 2005.  [PUBMED Abstract]
    
    
13. Franke AA, Cooney RV, Custer LJ, et al.: Inhibition of neoplastic transformation and bioavailability of dietary flavonoid agents. In: Manthey JA, Buslig BS, eds.: Flavonoids in the Living System. New York, NY: Plenum Press, 1998. Advances in Experimental Medicine and Biology, 439, pp 237-48. 
    
    
14. Waladkhani AR, Clemens MR: Effect of dietary phytochemicals on cancer development (review) Int J Mol Med 1 (4): 747-53, 1998.  [PUBMED Abstract]
    
    
15. de Witte P: Metabolism and pharmacokinetics of anthranoids. Pharmacology 47 (Suppl 1): 86-97, 1993.  [PUBMED Abstract]
    
    
16. Campbell MJ, Hamilton B, Shoemaker M, et al.: Antiproliferative activity of Chinese medicinal herbs on breast cancer cells in vitro. Anticancer Res 22 (6C): 3843-52, 2002 Nov-Dec.  [PUBMED Abstract]
    
    
17. Ottenweller J, Putt K, Blumenthal EJ, et al.: Inhibition of prostate cancer-cell proliferation by Essiac. J Altern Complement Med 10 (4): 687-91, 2004.  [PUBMED Abstract]
    
    
18. LeMoine L: Essiac: an historical perspective. Can Oncol Nurs J 7 (4): 216-21, 1997.  [PUBMED Abstract]
    
    
19. Bennett LM, Montgomery JL, Steinberg SM, et al.: Flor-Essence herbal tonic does not inhibit mammary tumor development in Sprague Dawley rats. Breast Cancer Res Treat 88 (1): 87-93, 2004.  [PUBMED Abstract]
    
    

History

Essiac was popularized in Canada during the 1920s, when the developer, a nurse from Ontario, began to advocate its use as a cancer treatment. In 1922, the developer obtained an herbal tea formula from a female breast cancer patient who claimed the mixture had cured her disease. Reviewed in [1-6] The patient reportedly received the formula from an Ontario Ojibwa Native American medicine man. The developer subsequently modified the formula, producing both injectable and oral forms of treatment. Reviewed in [2-9]

From 1934 to 1942, the developer operated a cancer clinic in Bracebridge, Ontario, and dispensed Essiac free of charge. Reviewed in [10] In 1938, members of the Royal Cancer Commission of Canada visited the clinic and heard testimonials from patients who had been treated with the mixture. Reviewed in [4,8] The Cancer Commission concluded there was only limited evidence for the effectiveness of Essiac. After years of controversy, the developer closed the clinic in 1942 but continued to provide Essiac to patients until the late 1970s. Reviewed in [4,5] (Refer to the Human/Clinical Studies ⁶ section of this summary for more information.)

From 1959 until the late 1970s, the developer collaborated with an American physician to conduct clinical and laboratory studies of Essiac and to promote its use. Reviewed in [4,8] This collaboration led to the development of the eight-herb formula now marketed as Flor•Essence. None of the results of these collaborative studies were reported in peer-reviewed scientific journals.

In 1977, the developer provided a four-herb recipe for Essiac to a Canadian corporation. Reviewed in [6,8] In 1978, the corporation filed a preclinical new drug submission with the Canadian Department of National Health and Welfare (Health Protection Branch) and was given permission to conduct clinical studies of Essiac’s safety and effectiveness in cancer patients. Reviewed in [4-6,8,9] In 1982, this permission was withdrawn when it was determined that the corporation had not fulfilled commitments to adequately control the manufacturing consistency of Essiac, to isolate and characterize active substances in the mixture, and to design and execute appropriate clinical trials. Reviewed in [4-6] During this period, restrictions were imposed on the promotion of Essiac as a cancer treatment, but the corporation was allowed to distribute it to cancer patients through their physicians under Canada’s Emergency Drug Release Program (also called Health Canada’s Special Access Programme). Reviewed in [8] While the preclinical new drug submission was in effect in Canada, the corporation filed an unsuccessful New Drug Application (NDA) with the U.S. Food and Drug Administration, seeking permission to market Essiac in the United States. Details of the NDA submission, which can be disclosed only by the corporation, have not been made public. Reviewed in [5] (Refer to the Human/Clinical Studies ⁶ section of this summary for more information.)

In the early 1980s, the Canadian Department of National Health and Welfare (Bureau of Human Prescription Drugs) conducted a retrospective review of case summaries submitted by physicians whose patients had obtained Essiac under the Emergency Drug Release Program. Reviewed in [2,5,8] The Department found little evidence to suggest that Essiac was effective as a cancer treatment. (Refer to the Human/Clinical Studies ⁶ section of this summary for more information.)

Also in the 1980s, the manufacturers of Essiac-like products began to market their formulations as health tonics and to avoid making claims of effectiveness in treating disease. Consequently, the mixtures were no longer subject to regulation as drugs. Reviewed in [4] Essiac is not currently available under Canada’s Emergency Drug Release Program.

In 1995, the corporation that acquired the four-herb recipe for Essiac from the developer dissolved voluntarily.[1] Later that year, a new company was formed to manufacture and distribute this proprietary herbal mixture.[1] Reviewed in [6]

References

1. Essiac. Kirkland, Canada: Altramed Health Products, 2002. Available online. ⁷ Last accessed March 07, 2008. 
   
   
2. Tamayo C: Essiac for cancer. Alternative Therapies in Women's Health 2 (3): 19-23, 2000. 
   
   
3. Locock RA: Essiac. Can Pharm J 130: 18-9, 1997. 
   
   
4. Reviews of Therapies: Herbal/plant therapies: Essiac. Houston, Tex: M.D. Anderson Cancer Center, 2002. Available online. ⁸ Last accessed March 07, 2008. 
   
   
5. Herbal treatments. In: US Congress, Office of Technology Assessment.: Unconventional Cancer Treatments. Washington, DC: U.S. Government Printing Office, 1990. OTA-H-405, pp 71-5. Also available online. ⁹ Last accessed March 07, 2008. 
   
   
6. LeMoine L: Essiac: an historical perspective. Can Oncol Nurs J 7 (4): 216-21, 1997.  [PUBMED Abstract]
   
   
7. Tamayo C, Richardson MA, Diamond S, et al.: The chemistry and biological activity of herbs used in Flor-Essence herbal tonic and Essiac. Phytother Res 14 (1): 1-14, 2000.  [PUBMED Abstract]
   
   
8. Kaegi E: Unconventional therapies for cancer: 1. Essiac. The Task Force on Alternative Therapies of the Canadian Breast Cancer Research Initiative. CMAJ 158 (7): 897-902, 1998.  [PUBMED Abstract]
   
   
9. Essiac. Toronto, Canada: Canadian Breast Cancer Research Alliance, 1996. 
   
   
10. The History of Essiac & Rene Caisse, Canada's Cancer Nurse. Kirkland, Canada: Altramed Health Products, 2001. Available online. ¹⁰ Last accessed March 07, 2008. 
    
    

Laboratory/Animal/Preclinical Studies

Essiac

In 2004, a mixture of the Essiac herbs showed a decreased proliferation in a prostate cancer cell line.[1] No other results of laboratory ( in vitro ) or animal ( in vivo ) studies of Essiac have been reported in the peer-reviewed scientific literature. Brief descriptions of three series of animal experiments, however, are available. Reviewed in [2]

In the mid-1970s, the developer submitted both dried and liquid samples of Essiac to the Memorial Sloan-Kettering Cancer Center in New York City for evaluation of its immunotherapeutic and chemotherapeutic potential. Reviewed in [2] No immunostimulatory or chemotherapeutic activity was detected in eight animal experiments that utilized the S-180 mouse sarcoma tumor model.

In the early 1980s, the corporation that acquired the four-herb recipe for Essiac from the developer submitted another sample to the Memorial Sloan-Kettering Cancer Center for evaluation in additional animal studies. No anticancer activity was detected in 17 separate experiments that utilized a variety of animal leukemia and tumor models. Reviewed in [2]

In 1983, the National Cancer Institute tested a liquid sample of Essiac that was provided by the manufacturer after the Canadian Department of National Health and Welfare (Health Protection Branch) requested that it be tested in animals. Reviewed in [2] These studies revealed no anticancer activity in the mouse P388 lymphocytic leukemia tumor system and found lethal toxicity at the highest concentrations of Essiac administered to test animals. It is not known, however, how the concentrations used in these animal tests compare with those achieved in humans after the consumption of the manufacturer's recommended doses.

There are conflicting results in the peer-reviewed literature. One study suggests that Flor•Essence enhances tumor growth in vitro, a finding that is contradictory to the widely available anecdotal evidence that this product suppresses or inhibits tumor development.[3] Another study suggests that the growth of human breast cancer cells is stimulated through estrogen receptor (ER)–mediated as well as ER–independent mechanisms of action from Flor•Essence and Essiac herbal tonics.[4] A third study demonstrated antiproliferative and differentiation-inducing properties in vitro only in high concentrations of Essiac and Flor•Essence herbal teas.[5]

The 2004 in vivo study of Flor•Essence in a rat model looked at mammary tumor development following administration of the herbal compound. Sprague-Dawley rats (N = 112) were assigned to one of three groups. The control group (n = 35) received water only. The second group (n = 40) received 3% Flor•Essence in their drinking water in an attempt to provide a dose equivalent to that recommended in the popular literature. The third group (n = 37) received 6% Flor•Essence in their drinking water to investigate the dose-response relationship. Mammary tumors were induced by a 40 mg/kg/bw dose of 7,12-dimethylbenz(a)anthracene. At 19 weeks, palpable mammary tumor incidence was greater (65% and 59.4%) in both Flor•Essence groups compared with controls (51%). Terminal necropsy was performed at age 23 weeks or when tumor burden became too great. Results showed mammary tumor incidence was 82.5% for controls compared with 90% and 97.3%, respectively, for rats consuming 3% and 6% Flor•Essence.[3]

Laboratory and animal experiments have shown that some of the chemicals in the herbs used to make Essiac and Flor•Essence have antioxidant, anti-inflammatory, estrogenic, or anticancer activity. Reviewed in [6-14]

Among the herbs used in both mixtures, burdock root (Arctium lappa L.) contains several flavonoids and polyphenols that have shown antioxidant activity; Indian rhubarb root (Rheum palmatum L.) contains several anthraquinones, including emodin and aloe-emodin, which have demonstrated anti-inflammatory and cytotoxic effects; sheep sorrel (Rumex acetosella L.) contains several types of anthraquinones, including emodin and aloe-emodin, as well as phytoestrogens, which may possess both procancer and anticancer activity; and slippery elm bark (Ulmus fulva Michx.) has been shown to contain antioxidants. Reviewed in [6-12]

Among the herbs found in Flor•Essence alone, watercress (Nasturtium officinale R.Br.)contains phenethyl isothiocyanate (PEITC), which has shown cytotoxic and antitumor activities; blessed thistle (Cnicus benedictus L.) contains cnicin, which is a sesquiterpene lactone that has demonstrated cytotoxic, antitumor, and anti-inflammatory effects, and arctiin and arctigenin, which are lignans that have shown anticancer activity; red clover (Trifolium pratense L.) contains a complex mixture of phytoestrogens including genistein, which has demonstrated antiangiogenic, estrogenic, and procancer and anticancer effects (depending on the dose); and extracts of kelp (Laminaria digitata [Hudson] Lamx.) have shown immunostimulatory and antitumor activities. Reviewed in [6,7,10,11,14]

Whether equivalent concentrations of relevant molecules can be achieved in the bloodstream of individuals who consume Essiac or Flor•Essence in the amounts recommended by their manufacturers has not been determined. An uncharacterized Flor•Essence commercial product was dosed at amounts less than those recommended by the manufacturers for humans, and there was an increase in tumor incidence in this model.[3]

References

1. Ottenweller J, Putt K, Blumenthal EJ, et al.: Inhibition of prostate cancer-cell proliferation by Essiac. J Altern Complement Med 10 (4): 687-91, 2004.  [PUBMED Abstract]
   
   
2. Herbal treatments. In: US Congress, Office of Technology Assessment.: Unconventional Cancer Treatments. Washington, DC: U.S. Government Printing Office, 1990. OTA-H-405, pp 71-5. Also available online. ⁹ Last accessed March 07, 2008. 
   
   
3. Bennett LM, Montgomery JL, Steinberg SM, et al.: Flor-Essence herbal tonic does not inhibit mammary tumor development in Sprague Dawley rats. Breast Cancer Res Treat 88 (1): 87-93, 2004.  [PUBMED Abstract]
   
   
4. Kulp KS, Montgomery JL, Nelson DO, et al.: Essiac and Flor-Essence herbal tonics stimulate the in vitro growth of human breast cancer cells. Breast Cancer Res Treat 98 (3): 249-59, 2006.  [PUBMED Abstract]
   
   
5. Tai J, Cheung S, Wong S, et al.: In vitro comparison of Essiac and Flor-Essence on human tumor cell lines. Oncol Rep 11 (2): 471-6, 2004.  [PUBMED Abstract]
   
   
6. Tamayo C, Richardson MA, Diamond S, et al.: The chemistry and biological activity of herbs used in Flor-Essence herbal tonic and Essiac. Phytother Res 14 (1): 1-14, 2000.  [PUBMED Abstract]
   
   
7. Tamayo C: Essiac for cancer. Alternative Therapies in Women's Health 2 (3): 19-23, 2000. 
   
   
8. Kaegi E: Unconventional therapies for cancer: 1. Essiac. The Task Force on Alternative Therapies of the Canadian Breast Cancer Research Initiative. CMAJ 158 (7): 897-902, 1998.  [PUBMED Abstract]
   
   
9. Essiac. Toronto, Canada: Canadian Breast Cancer Research Alliance, 1996. 
   
   
10. Franke AA, Cooney RV, Custer LJ, et al.: Inhibition of neoplastic transformation and bioavailability of dietary flavonoid agents. In: Manthey JA, Buslig BS, eds.: Flavonoids in the Living System. New York, NY: Plenum Press, 1998. Advances in Experimental Medicine and Biology, 439, pp 237-48. 
    
    
11. Waladkhani AR, Clemens MR: Effect of dietary phytochemicals on cancer development (review) Int J Mol Med 1 (4): 747-53, 1998.  [PUBMED Abstract]
    
    
12. de Witte P: Metabolism and pharmacokinetics of anthranoids. Pharmacology 47 (Suppl 1): 86-97, 1993.  [PUBMED Abstract]
    
    
13. Campbell MJ, Hamilton B, Shoemaker M, et al.: Antiproliferative activity of Chinese medicinal herbs on breast cancer cells in vitro. Anticancer Res 22 (6C): 3843-52, 2002 Nov-Dec.  [PUBMED Abstract]
    
    
14. Boué SM, Wiese TE, Nehls S, et al.: Evaluation of the estrogenic effects of legume extracts containing phytoestrogens. J Agric Food Chem 51 (8): 2193-9, 2003.  [PUBMED Abstract]
    
    

Human/Clinical Studies

Essiac

No report of a clinical study of Essiac has been published in the peer-reviewed scientific literature. Brief descriptions of one incomplete clinical study and one retrospective evaluation of Essiac as a treatment for cancer have been published. Reviewed in [1-6] It is not clear whether the described patient populations consisted entirely of adults or whether they included children.

As noted previously (refer to the History ¹² section of this summary for more information), the developer provided a four-herb recipe for Essiac to a Canadian corporation in 1977. Reviewed in [2,6] In 1978, the corporation filed a preclinical new drug submission with the Canadian Department of National Health and Welfare (Health Protection Branch) and was given permission to conduct studies on the safety and the efficacy of Essiac in cancer patients. Reviewed in [2,4-8] In 1982, the Department withdrew its permission after determining the research was not being conducted as planned (refer to the History ¹² section of this summary for more information). Reviewed in [2,4-8] At that time, the available incomplete data were reviewed, and no clear evidence of improved survival could be demonstrated for treated patients. Reviewed in [1,2,5,6] Pain control and quality of life were not assessed in these studies. The review of the data indicated, however, that Essiac was not toxic. Reviewed in [5,6] Because no evidence of harm was found, the Canadian government allowed the corporation to distribute Essiac to cancer patients through their physicians under Canada’s Emergency Drug Release Program. Nonetheless, restrictions were imposed on the promotion of Essiac as a treatment for cancer. Reviewed in [2] Access to Essiac under Canada’s Emergency Drug Release Program has since been discontinued.

In the early 1980s, the Canadian Department of National Health and Welfare (Bureau of Human Prescription Drugs) conducted a retrospective review of data voluntarily submitted by physicians for 86 cancer patients who had gained access to Essiac under Canada’s Emergency Drug Release Program during the period between 1978 and 1982. Reviewed in [1,2,4] (Note: [2] states that data from 87 patients were reviewed.) The Bureau’s evaluation was based on written summaries submitted by the physicians and not on a review of the original patient records. Reviewed in [4] The Bureau found 47 patients did not benefit from Essiac, one had subjective improvement, five required fewer analgesics, four had an objective response, and four were in stable condition. Reviewed in [1,4] Among the remaining 25 patients, 17 had died, and the reports for 8 were considered unevaluable. The Bureau solicited additional information about the four patients who had an objective response and the four patients who were in stable condition. This additional information revealed that, among these eight patients, two had died, three had progressive disease, and three remained in stable condition. Reviewed in [1,4] The three patients in stable condition had received previous conventional therapy. Therefore, the benefits of treatment for these patients, if any, could not be clearly ascribed to Essiac. Reviewed in [4]

No results of human studies of Flor•Essence have been reported anecdotally or in the peer-reviewed scientific literature.

References

1. Tamayo C: Essiac for cancer. Alternative Therapies in Women's Health 2 (3): 19-23, 2000. 
   
   
2. Kaegi E: Unconventional therapies for cancer: 1. Essiac. The Task Force on Alternative Therapies of the Canadian Breast Cancer Research Initiative. CMAJ 158 (7): 897-902, 1998.  [PUBMED Abstract]
   
   
3. Locock RA: Essiac. Can Pharm J 130: 18-9, 1997. 
   
   
4. Herbal treatments. In: US Congress, Office of Technology Assessment.: Unconventional Cancer Treatments. Washington, DC: U.S. Government Printing Office, 1990. OTA-H-405, pp 71-5. Also available online. ⁹ Last accessed March 07, 2008. 
   
   
5. Essiac. Toronto, Canada: Canadian Breast Cancer Research Alliance, 1996. 
   
   
6. LeMoine L: Essiac: an historical perspective. Can Oncol Nurs J 7 (4): 216-21, 1997.  [PUBMED Abstract]
   
   
7. Reviews of Therapies: Herbal/plant therapies: Essiac. Houston, Tex: M.D. Anderson Cancer Center, 2002. Available online. ⁸ Last accessed March 07, 2008. 
   
   
8. Campbell MJ, Hamilton B, Shoemaker M, et al.: Antiproliferative activity of Chinese medicinal herbs on breast cancer cells in vitro. Anticancer Res 22 (6C): 3843-52, 2002 Nov-Dec.  [PUBMED Abstract]
   
   

Adverse Effects

Nausea and vomiting are the only reported adverse effects associated with the use of Essiac. Reviewed in [1] The manufacturer of Flor•Essence states that users may experience increased bowel movements, frequent urination, swollen glands, skin blemishes, flu-like symptoms, or slight headaches.[2]

References

1. Herbal treatments. In: US Congress, Office of Technology Assessment.: Unconventional Cancer Treatments. Washington, DC: U.S. Government Printing Office, 1990. OTA-H-405, pp 71-5. Also available online. ⁹ Last accessed March 07, 2008. 
   
   
2. Flora Flor•Essence®. Burnaby, Canada: Flora Manufacturing & Distributing Ltd. Available online. ¹¹ Last accessed March 07, 2008. 
   
   

Overall Level of Evidence for Essiac and Flor•Essence

To assist readers in evaluating the results of human/clinical studies of complementary and alternative medicine (CAM) treatments for cancer, a scoring system has been devised that allows studies of individual treatments to be ranked according to the strength of their evidence (i.e., their level of evidence). Not all studies, however, are given a level of evidence score. To be eligible, a study must:

• Evaluate a therapeutic outcome or outcomes, such as tumor response, improvement in survival, or carefully measured improvement in quality of life.
• Be reported in a peer-reviewed scientific journal.
• Have its clinical findings published in sufficient detail that a meaningful evaluation can be made.

Evidence from studies that do not meet these requirements is considered extremely weak. In addition to scoring individual studies, an overall level of evidence assessment is usually made.

Because no study of the use of Essiac or Flor•Essence in humans has been reported in a peer-reviewed scientific journal, no level of evidence analysis is possible for these mixtures. The data that are available, however, do not support claims that Essiac and Flor•Essence can detoxify the body, strengthen the immune system, or fight cancer. At this time, evidence does not support the use of either Essiac or Flor•Essence in the treatment of cancer patients outside the context of well-designed clinical trials.

Separate levels of evidence scores are assigned to qualifying human studies on the basis of statistical strength of the study design and scientific strength of the treatment outcomes (i.e., endpoints) measured. The resulting two scores are then combined to produce an overall score. For additional information about levels of evidence analysis, refer to Levels of Evidence for Human Studies of Cancer Complementary and Alternative Medicine ².

Changes to This Summary (03/20/2008)

The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

Editorial changes were made to this summary.

More Information

Additional Information about CAM Therapies

• The National Center for Complementary and Alternative Medicine ¹³ (NCCAM).
• The National Cancer Institute Office of Cancer Complementary and Alternative Medicine ¹⁴ (OCCAM).
• CAM on PubMed ¹⁵, a special subset of the PubMed scientific literature database created through a partnership between NCCAM and the National Library of Medicine.

About PDQ

• PDQ® - NCI's Comprehensive Cancer Database ¹⁶

  Full description of the NCI PDQ database.

Other PDQ Summaries

• PDQ® Cancer Information Summaries: Adult Treatment ¹⁷

  Treatment options for adult cancers.

• PDQ® Cancer Information Summaries: Pediatric Treatment ¹⁸

  Treatment options for childhood cancers.

• PDQ® Cancer Information Summaries: Supportive and Palliative Care ¹⁹

  Side effects of cancer treatment, management of cancer-related complications and pain, and psychosocial concerns.

• PDQ® Cancer Information Summaries: Screening/Detection (Testing for Cancer) ²⁰

  Tests or procedures that detect specific types of cancer.

• PDQ® Cancer Information Summaries: Prevention ²¹

  Risk factors and methods to increase chances of preventing specific types of cancer.

• PDQ® Cancer Information Summaries: Genetics ²²

  Genetics of specific cancers and inherited cancer syndromes, and ethical, legal, and social concerns.

• PDQ® Cancer Information Summaries: Complementary and Alternative Medicine ²³

  Information about complementary and alternative forms of treatment for patients with cancer.

Important:

This information is intended mainly for use by doctors and other health care professionals. If you have questions about this topic, you can ask your doctor, or call the Cancer Information Service at 1-800-4-CANCER (1-800-422-6237).

Glossary Terms

A disease caused by human immunodeficiency virus (HIV). People with acquired immunodeficiency syndrome are at an increased risk for developing certain cancers and for infections that usually occur only in individuals with a weak immune system. Also called AIDS.

An unwanted side effect of treatment.

A substance found in certain plants, including aloe vera. It belongs to a family of compounds called anthraquinones, which have shown anti-inflammatory and anticancer effects.

A drug that reduces pain. Analgesics include aspirin, acetaminophen, and ibuprofen.

An incomplete description of the medical and treatment history of one or more patients. Anecdotal reports may be published in places other than peer-reviewed, scientific journals.

A type of anticancer drug.

Having to do with reducing inflammation.

Having to do with reducing the growth of new blood vessels.

A substance that protects cells from the damage caused by free radicals (unstable molecules made by the process of oxidation during normal metabolism). Free radicals may play a part in cancer, heart disease, stroke, and other diseases of aging. Antioxidants include beta-carotene, lycopene, vitamins A, C, and E, and other natural and manufactured substances.

A substance found in certain plants, including burdock. It has shown antiviral and anticancer effects. Arctigenin belongs to a group of substances called lignans.

A substance found in certain plants, including burdock. It has shown anticancer effects. Arctiin belongs to a group of substances called lignans.

A plant whose leaves, stems, and flowers have been used in some cultures to treat certain medical problems. Blessed thistle may have anti-inflammatory and anticancer effects. The scientific name is Cnicus benedictus. Also called cardin, holy thistle, spotted thistle, and St. Benedict's thistle.

A plant whose seeds and root have been used in some cultures to treat certain medical problems. It may have antioxidant effects. The scientific name is Arctium lappa. Also called happy major and lappa.

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.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

Treatment with drugs that kill cancer cells.

A disease or condition that persists or progresses over a long period of time.

A type of chronic, progressive liver disease in which liver cells are replaced by scar tissue.

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 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 clinical study.

A substance found in certain plants, including blessed thistle. It has been used in some cultures to treat certain medical problems. It may have anti-inflammatory and anticancer effects. Cnicin is a type of sesquiterpene lactone.

Inflammation of the colon.

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.

A currently accepted and widely used treatment for a certain type of disease, based on the results of past research. Also called conventional treatment.

A currently accepted and widely used treatment for a certain type of disease, based on the results of past research. Also called conventional therapy.

Cell-killing.

To make something less poisonous or harmful. It may refer to the process of removing toxins, poisons, or other harmful substances from the body.

Any of several diseases in which the kidneys make a large amount of urine. Diabetes usually refers to diabetes mellitus in which there is also a high level of glucose (a type of sugar) in the blood because the body does not make enough insulin or use it the way it should.

A product that is added to the diet. A dietary supplement is taken by mouth, and usually contains one or more dietary ingredient (such as vitamin, mineral, herb, amino acid, and enzyme). Also called nutritional supplement.

The amount of medicine taken, or radiation given, at one time.

Inflammation of the duodenum (the first part of the small intestine that connects to the stomach).

Effectiveness. In medicine, the ability of an intervention (for example, a drug or surgery) to produce the desired beneficial effect.

A substance found in certain plants, including rhubarb. It belongs to a family of compounds called anthraquinones, which have shown anti-inflammatory and anticancer effects.

In clinical trials, an event or outcome that can be measured objectively to determine whether the intervention being studied is beneficial. The endpoints of a clinical trial are usually included in the study objectives. Some examples of endpoints are survival, improvements in quality of life, relief of symptoms, and disappearance of the tumor.

Inflammation of the esophagus (the tube that carries food from the mouth to the stomach).

An herbal tea mixture that contains burdock root, Indian rhubarb root, sheep sorrel, and slippery elm bark. It has been claimed to remove toxins from the body, make the immune system stronger, relieve pain, control diabetes, treat AIDS, reduce tumor size, increase cancer survival, and improve quality of life. No clinical trial using Essiac in humans has been reported in a peer-reviewed, scientific journal, and the FDA has not approved the use of Essiac for the treatment of any medical conditions.

A member of a group of substances found in many plants and plant-based foods. Flavonoids have shown antioxidant effects.

Liquid.

An agency in the U.S. federal government whose mission is to protect public health by making sure that food, cosmetics, and nutritional supplements are safe to use and truthfully labeled. The Food and Drug Administration also makes sure that drugs, medical devices, and equipment are safe and effective, and that blood for transfusions and transplant tissue are safe. Also called FDA.

Inflammation of the lining of the stomach.

Refers to the stomach and intestines. Also called GI.

An isoflavone found in soy products. Soy isoflavones are being studied to see if they help prevent cancer.

Having to do with plants.

The complex group of organs and cells that defends the body against infections and other diseases.

A substance that increases the ability of the immune system to fight infection and disease.

Treatment to boost or restore the ability of the immune system to fight cancer, infections, and other diseases. Also used to lessen certain side effects that may be caused by some cancer treatments. Agents used in immunotherapy include monoclonal antibodies, growth factors, and vaccines. These agents may also have a direct antitumor effect. Also called biological response modifier therapy, biological therapy, biotherapy, and BRM therapy.

In the laboratory (outside the body). The opposite of in vivo (in the body).

In the body. The opposite of in vitro (outside the body or in the laboratory).

The root of this plant has been used in some cultures to treat certain medical problems. It may have anti-inflammatory and anticancer effects. The scientific name is Rheum palmatum or Rheum officinale. Also called Chinese rhubarb, da-huang, rhubarb, and Turkish rhubarb.

Taking into the body by mouth.

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

Injection into muscle.

In clinical trials, refers to a drug (including a new drug, dose, combination, or route of administration) or procedure that has undergone basic laboratory testing and received approval from the U.S. Food and Drug Administration (FDA) to be tested in human subjects. A drug or procedure may be approved by the FDA for use in one disease or condition, but be considered investigational in other diseases or conditions. Also called experimental.

A researcher in a clinical trial or clinical study.

A type of seaweed. The stem-like parts of this plant have been used in some cultures to treat certain medical problems. It may have immunostimulatory and anticancer effects. The scientific name is Laminaria digitata.

Research done in a laboratory. These studies may use test tubes or animals to find out if a drug, procedure, or treatment is likely to be useful. Laboratory studies take place before any testing is done in humans.

Cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of blood cells to be produced and enter the bloodstream.

A ranking system used to describe the strength of the results measured in a clinical trial or research study. The design of the study (such as a case report for an individual patient or a randomized double-blinded controlled clinical trial) and the endpoints measured (such as survival or quality of life) affect the strength of the evidence.

A member of a group of substances found in plants that have shown estrogenic and anticancer effects. Lignans have been used in some cultures to treat certain medical problems.

A large organ located in the upper abdomen. The liver cleanses the blood and aids in digestion by secreting bile.

A type of cancer in which the bone marrow makes too many lymphocytes (white blood cells).

Having to do with the breast.

A measure of volume for a liquid. A milliliter is approximately 950 times smaller than a quart and 30 times smaller than a fluid ounce. A milliliter of liquid and a cubic centimeter (cc) of liquid are the same.

The smallest particle of a substance that has all of the physical and chemical properties of that substance. Molecules are made up of one or more atoms. If they contain more than one atom, the atoms can be the same (an oxygen molecule has two oxygen atoms) or different (a water molecule has two hydrogen atoms and one oxygen atom). Biological molecules, such as proteins and DNA, can be made up of many thousands of atoms.

A feeling of sickness or discomfort in the stomach that may come with an urge to vomit. Nausea is a side effect of some types of cancer therapy.

A measurable response.

By or having to do with the mouth.

A measure of weight (one-sixteenth pound) and volume (one-eighth cup).

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.

A substance being studied in the prevention of cancer. It is a naturally occurring compound found in some cruciferous vegetables. Also called PEITC.

An estrogen-like substance found in some plants and plant products. Phytoestrogens may have anticancer effects.

A substance that is found in many plants and gives some flowers, fruits, and vegetables their color. Polyphenols have antioxidant activity.

In medicine, the effect of increasing the potency or effectiveness of a drug or other treatment.

Research using animals to find out if a drug, procedure, or treatment is likely to be useful. Preclinical studies take place before any testing in humans is done.

Cancer that is growing, spreading, or getting worse.

Cancer that forms in tissues of the prostate (a gland in the male reproductive system found below the bladder and in front of the rectum). Prostate cancer usually occurs in older men.

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.

The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called irradiation and radiotherapy.

Trifolium pratense. A plant with flowers that has been used in some cultures to treat certain medical problems. It is being studied in the relief of menopausal symptoms and may have anticancer effects. Also called purple clover, Trifolium pratense, and wild clover.

In medicine, an improvement related to treatment.

Looking back at events that have already taken place.

A cancer of the bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.

A person who has studied science, especially one who is active in a particular field of investigation.

A substance found in some plants. Sesquiterpene lactones may have anti-inflammatory and anticancer effects. Plants containing sesquiterpene lactones have been used in some cultures to treat certain medical problems.

A plant that has been used in some cultures to treat certain medical problems. It may have anticancer effects. The scientific name is Rumex acetosella. Also called dock and sorrel.

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.

The inner bark of this plant has been used in some cultures to treat certain medical problems. It may have antioxidant effects. Also called gray elm, Indian elm, red elm, sweet elm, Ulmus fulva, and Ulmus rubra.

An improvement that is reported by the patient, but cannot be measured by the healthcare provider (for example, "I feel better").

Having to do with treating disease and helping healing take place.

Having to do with poison or something harmful to the body. Toxic substances usually cause unwanted side effects.

Cells, tissues, or animals used to study the development and progression of cancer, and to test new treatments before they are given to humans. Animals with transplanted human tumors or other tissues are called xenograft models.

To eject some or all of the contents of the stomach through the mouth.

Parts of the flowering plant have been used in some cultures to treat certain medical problems. It may have anticancer effects. The scientific name is Nasturtium officinale. Also called Indian cress.