Breast Cancer and Botanical Medicine
Part I of II-Part Series
By Steven Gomberg, LAC, CCN, RH (AHG), and Brandon Horn, PHD, JD, LAC The authors are licensed acupuncturists and board certified oriental medicine practitioners for the Eastern Center for Complementary Medicine, Los Angeles; they both report no financial relationships relevant to this field of study.
The following article has two objectives: to provide clinically relevant information on the use of herbs in the treatment of breast cancer and to provide a context for their use. What follows is a distillation of some of the more effective botanicals and some suggestions about how to use them in the setting of breast cancer.
Background
Breast cancer is one of the leading causes of cancer-related death in women.1 The overall risk for women developing breast cancer is 1 in 8, with the highest risk occurring in women over the age of 60.2 Breast cancer accounts for almost a third of all new cancers that are diagnosed in the United States and 16% of all cancer-related mortalities in the United States.3 Worldwide, 1 million cases of breast cancer are diagnosed annually. The five-year survival rates are almost 100% for stage I disease, but only 20% for stage IV.4
Risk Factors
Although there are general predisposing risk factors such as race, family history, and age, there are many individualized risk factors as well. As a broad overview, we will categorize cancer risk factors as: genetic/familial risks and environmental/lifestyle risks.5
Genetic/Familial
Genetic factors seem to play a more significant role in the development of breast cancer in premenopausal women.6 Mutations in the BRCA 1 and 2 tumor suppressor genes are among the most common genetic risk factors for developing cancer, with an overall lifetime risk of 60%-80%.7 BRCA mutations are more prevalent among certain patient populations, such as women of Ashkenazic Jewish descent. Curiously, increased consumption of coffee may reduce breast cancer risk in these women.8 Another genetic factor appears to be mutations in tumor suppressor genes, such as p53.
Use of specific medications, or a history of certain illnesses, may also contribute to risk for breast cancer. For example, prior or current use of hormone replacement therapy,9 obesity, certain forms of infertility, and fibrocystic breast disease are also known risk factors.
Environment/Lifestyle
Note: For an in-depth review of the various environmental/lifestyle exposures with citations, the reader is referred to: State of the Evidence 2008: The Connection between Breast Cancer and the Environment.10
Environmental exposures (eg, xenosteroids, organochlorines11 and other chemicals, radiation,11 etc.), lifestyle (eg, smoking, alcohol, etc.), and diet (eg, xenosteroidal compounds, growth hormones10 carcinogenic byproducts of manufacturing or cooking, food additives, etc.) may also be contributing factors. Clearly there is substantial overlap. For example, recent studies have shown that high consumption of dietary fat does not pose a risk in and of itself.12 However, certain high fat diets can lead to obesity, which is a risk factor.2 Dietary fats can also contain high concentrations of fat soluble contaminants (eg, xenosteroids), which may contribute to cancer pathogenesis. High fat-to-complex carbohydrate ratio diets have also been associated in some studies with dense breast tissue, another known risk factor.12
The Strategic Use of Herbs in Breast Cancer
Many useful and novel compounds have been identified within the Chinese Herbal Pharmacopeia with a wide range of effects. Some are directly tumoricidal, where others inhibit aromatase, upregulate p53, induce apoptosis, inhibit cell-cell adhesion pathways, and so forth.
The choice of herbal research targets in breast cancer therapy is often derived from observance of traditional uses. Practitioners of Classical Chinese Medicine (CM) choose herbs based upon a complex synthesis of diagnostic parameters combined with an intricate theoretical model. Essentially, CM views tumors as a physiological response of the body to sequester a pathogen and attempt to keep it from spreading or harming other tissue. Metastasis, therefore, is seen as the loss of the body's ability to contain, eliminate, or repair the pathology (This view is not representative of all Chinese Medicine traditions, but is very pertinent and analogous in many ways to modern discoveries).
Accordingly, three main factors are strategically addressed: 1) the underlying pathology (ie, aberrant cells), 2) the etiological factors involved in that pathology (ie, factors that create the microenvironment facilitating the tumor; these can include toxins, microorganisms, emotions/stressors, etc.), and 3) the body's ability to control the pathogen, prevent metastasis, and maintain homeostasis (ie, immune system, digestive system, etc.).
Addressing the underlying pathology
Note to readers: Please see accompanying chart for references to clinical statements.
The first factor involves directly addressing the aberrant cells in the tumor and their mechanisms of promoting abnormal cell growth (eg, estrogen receptors in an ER + tumor). In this respect, certain herbs may act synergistically with chemotherapy, radiation, and estrogen antagonists. Due to the novel actions of many herbs, it is also possible to utilize herbs where conventional therapies are not indicated, or as an option in cases where it is unclear whether conventional therapies will be more helpful or harmful.
Herbs used in this arena have various targets. Some seem to directly suppress tumor growth, induce apoptosis, or induce DNA repair mechanisms, where biothers seem to inhibit angiogenesis, cell adhesion pathways, metastasis, or block estrogen receptors. Several of the more useful herbs in this category include: Curcumae longae (eg, cell adhesion pathway inhibition), Salvia miltiorrhiza (eg, inhibits both estrogen receptor positive and negative tumors), Boswellia serrata (eg, metastasis inhibition), Ganoderma lucidum (eg, decreases estrogen receptor signaling and downregulates ER alpha expression), Tanacetum parthenium (eg, induces apoptosis), Scutellaria baicalensis (eg, inhibits multi-drug resistance and promotes DNA repair), and Scutellaria barbata (eg, selectively cytotoxic to breast cancer cells leaving normal mammary tissue unharmed).
References
1. Abeloff M, et al. Clinical Oncology. Philadelphia PA: Elsevier 2004
2. Cancer Facts and Figures. Atlanta GA: American Cancer Society 1999
3. Key TJ, et al. Epidemiology of breast cancer. Lancet Oncol. 2001;2:133-140.
4. How is cancer staged. Atlanta GA: American Cancer Society 1998. www.cancer.org
5. King SE, Schottenfeld D. The "epidemic" of breast cancer in the US determining the factors. Oncology (Williston Park). 1996;10:453-462.
6. Vogel VG. Breast cancer in younger women: assessment and risk management. The Female Patient. 1999;24:81-86.
7. King MC, et al. Breast and ovarian cancer risks due to inherited mutations in BRCA1 and BRCA2. Science. 2003;302:643-646.
8. Nkondjok A, et al. Coffee consumption and breast cancer risk among BRCA1 and BRCA2 mutation carriers. Int J Cancer. 2006;118:103-107.
9. Breast cancer and hormone replacement therapy: collaborative reanalysis of data from 51 epidemiological studies of 52,705 women with breast cancer and 108,411 women without breast cancer. Lancet. 1997; 350:1047-1059.
10. Baral E, et al. Breast cancer following irradiation of the breast. Cancer. 1977;40:2905-2910.
11. Gray J. State of the evidence 2008: the connection between breast cancer and the environment. The Breast Cancer Fund. 2008
12. Pischon T, et al. Obesity and cancer. Proc Nutr Soc. 2008;67:128-145.
Gomberg S, Horn B. Breast Cancer and Botanical Medicine. Alter Ther Women’s Health. 2008;10:65-69.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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