Evaluation of Essiac Tea to Prevent Mammary Tumors

Institution: Lawrence Livermore National Laboratory
Investigator(s): Kristen Kulp, Ph.D. -
Award Cycle: 2001 (Cycle VII) Grant #: 7IB-0003 Award: $182,593
Award Type: IDEA
Research Priorities
Etiology and Prevention>Prevention and Risk Reduction: ending the danger of breast cancer



Initial Award Abstract (2001)
Breast cancer will be diagnosed in 18,000 Californian women in 2001. Preventing breast cancer, both primary tumors and recurrences, is preferable to treating disease. The purpose of this research is to determine if Essiac tea, a complementary therapy widely self-administered by breast cancer survivors and patients, prevents breast cancer. Complementary therapies are not always discussed with physicians. When alternative approaches are discussed, counseling is hindered by large gaps in knowledge about safety, efficacy, and potential drug interactions. Essiac Tea, an herbal mixture introduced in the 1920’s to treat cancer, is commonly used today by breast cancer survivors to try to prevent recurrence. The biological activities of the individual herbs used in one Essiac tea formulation have characteristics associated with decreasing cancer risk. Many herbs used in Essiac tea have long histories of use in Asian diets and medicines. In spite of its potential benefits, Essiac tea is not the subject of any published reports evaluating its efficacy to prevent breast cancer. Because it is widely used, it is important to fill the knowledge gap about the ability of Essiac tea to prevent cancer.

The central question addressed by this application is: "To what extent does Essiac tea treatment reduce mammary tumor development in rodents?" The ducts of the mammary gland, through which milk is delivered to the suckling newborn, can be visualized as tree branches. We expect that Essiac exposure will reduce tumors and that this reduction will be associated with changes in the branching pattern of the mammary tree.

Two mammalian models (models with mammary glands) will be used to determine if drinking Essiac tea can reduce cancer development. Mammary tumor inhibition by Essiac tea will be studied in rats that are treated with a chemical to induce tumors. This approach is well-described and its use in tumor prevention studies is well-accepted by the scientific community. A mouse model will be used that develops mammary tumors because the Neu oncogene (a cancer gene) is overactive which results in uncontrolled cell growth in the mammary ducts. Thirty percent of breast tumors make too much of the Her-2/Neu cancer protein; patients with this type of breast tumor have lower survival and an increased risk of metastasis than other breast cancer patients. In this study, the number of animals with tumors, the average number of tumors per animal, and the complexity of ductal branching will be compared between Essiac tea treated and untreated animals.

This proposal is unique because it will rigorously test Essiac tea for its ability to prevent mammary tumors in well established animal models. In addition to the evaluation of Essiac on tumor development, ductal branching patterns will also be studied. If Essiac tea does not inhibit or increases mammary tumor development, this information could be used to direct patients to other complementary therapies. If mammary tumors are inhibited by Essiac tea, this would open doors to perform studies in cancer survivors to evaluate the ability of Essiac tea to prevent recurrence and to determine how our daughters might benefit from its use with population studies. In addition, studies would be designed to determine how Essiac tea works, what affect it has on the body, and if there are herbal-drug interactions. These studies would be necessary to develop science-based recommendations for its use among Californians.


Final Report (2003)
Women diagnosed with breast cancer often self-administer complementary and alternative medicine (CAM) to augment conventional treatments, improve health, or prevent recurrence. Approximately 50% of patients using CAM don’t inform their physicians and if they do counseling is often hindered by the lack of scientific knowledge about CAM. Breast cancer patients and survivors use herbal tonics like Essiac® and Flor-Essence® Herbal Tonics because of anecdotal evidence that they can treat or prevent disease. Flor-Essence® is a complex mixture of eight herbal extracts. The eight individual herbs have estrogenic, cytotoxic, anti-tumor, anti-mutagenic, anti-oxidant, and anti-inflammatory properties, among others. There have been no scientific studies done to evaluate these herbal tonics in cells, animal models, or clinical trials.

This project had two specific aims:
  1. To determine if Essiac exposure reduces mammary tumor incidence and/or multiplicity in rats treated with dimethylbenz[a]anthracene (DMBA), a well-recognized mammary gland carcinogen. The DMBA rat model of mammary carcinogenesis is a well accepted model in which to study mammary tumor prevention
  2. To determine if Essiac exposure inhibits mammary tumor development in (MMTV)c-neu transgenic mice, a mouse model in which mammary tumors develop spontaneously due to c-neu oncogene over-expression. This model is relevant to humans because patients whose breast tumors overexpress Her-2/Neu have reduced survival and an increased risk of metastasis compared to patients whose tumors do not. Approximately 30% of breast tumors overexpress the Her-2/Neu oncogene
We made progress in both aims as follows: The results from Specific Aim 1 suggest Flor-Essence® promotes the growth of DMBA-induced rat mammary tumors, although the results from Aim 2 suggest that in some instances some part of this complex mixture may be protective. Women who purchase Flor-Essence® after having been diagnosed with breast cancer use it in hopes that it will cure disease or prevent recurrence. It is important to understand the biologic consequences of self-administration of commercially available CAM on the breast. These studies are necessary for consumers and physicians to make informed decisions about CAM use.


Symposium Abstract (2003)
Women diagnosed with breast cancer often self-administer complementary and alternative medicine (CAM) to augment conventional treatments, improve health, or prevent recurrence. Physician counseling about the use of these products is often hindered by the lack of scientific knowledge about CAM. Breast cancer patients and survivors use herbal tonics like Essiac® and Flor-Essence® because of anecdotal evidence that the tonics can treat or prevent disease. Essiac® is a combination of four herbal extracts and Flor-Essence® adds four additional extracts to the basic recipe. The individual herbs have estrogenic, cytotoxic, anti-tumor, anti-mutagenic, anti-oxidant, and anti-inflammatory properties, among others. There have been no scientific studies done to evaluate these herbal tonics in cells, animal models, or clinical trials.

We are using cellular and animal models to evaluate the consequences of Flor-Essence® and Essiac® exposure on the breast. Cell proliferation assays in estrogen receptor positive (MCF-7) and estrogen receptor negative (MDA-MB-436) breast cancer cells demonstrated that exposures ranging from 1 to 8% Essiac® and Flor-Essence® stimulate growth up to 180% compared to untreated cells. There is no significant difference in growth stimulation between Essiac® and Flor-Essence® in either cell type. In estrogen receptor activation assays, Essiac® and Flor-Essence® stimulate estrogen receptors to levels similar to physiological estrogen and genestein. Flor-Essence® also stimulates the growth of DMBA-induced mammary tumors in Sprague Dawley rats. Female rats are given a 3% or 6% solution of Flor-Essence® or water alone for 23 weeks beginning at one day of age. DMBA is administered at 7 weeks of age to induce mammary tumors. At 16 weeks of age, control rats had a palpable mammary tumor incidence of 16% compared to 40% in the 3% and 27% in the 6% Flor-Essence® treated groups. At the end of the study 82% and 86% of rats treated with 3% and 6% Flor-Essence® had palpable tumors, respectively, compared to 71% in the control group. The average number of tumors observed was approximately 2-fold greater in the treated compared to control group. Preliminary results suggest that Flor-Essence® administration does not affect tumor development in mice with a mutated Her2/Neu gene. However administration during gestation has a persistent influence on body weight of the female offspring.

Both Essiac® and Flor-Essence® have growth promoting effects on some breast cancer cells and Flor-Essence® promotes tumor growth in DMBA treated rats. These studies are important for the development of science-based recommendations for CAM use among women in our communities. This work was performed under the auspices of the U. S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48. The work was supported by the California Breast Cancer Research Program # 7IB-0003 and LDRD funding #02-FS-006.