Breast Cancer Research
Breast cancer is the most common form of cancer among women in Europe , North and South America and Austral-Asia. Figures compiled by the World Health Organization over the past 40 years show a steady increase in both the incidence of and the death rate from breast cancer, and only within the past 5 years has this been seen to plateau. Although not confirmed, it is thought that the recent decline in incidence and mortality may be due to several factors including, but not limited to, earlier detection, increased knowledge by the patients of contributory and protective dietary factors, and the use of modern endocrine-modulating drugs. However, these statistics must be viewed critically since each country may apply different criteria to the diagnosis of cancer, and that these criteria may change over time.
A number of factors are recognized which increase a woman’s risk of developing breast cancer. Hormones play a major role in the etiology of several malignancies; specifically, the cumulative exposure of the breast to estrogen and progesterone leads to the risk of developing breast cancer [1]. Up to 75% of women with breast cancer have no significant family history of breast cancer. However, the variation in incidence throughout populations, and changes relating to population migration and adoption of altered lifestyles, all point to the critical importance of non-genetic determinants. Such factors include early menarche, late menopause, late age at birth of first child or nulliparity, a history of benign breast disease, breast density [2], environmental exposures especially to xeno-estrogens [3], and diet [4-8]. It is suggested that dietary modification with the introduction of soy products, curcumin, cruciferous vegetables and low fat may be beneficial in reducing the risk of developing cancer, possibly by inhibiting xeno-estrogenic effects of some pesticides [9]. 
Breast cancer research has developed at a rapid pace over the last four decades. Age, race, tumor size, histological tumor type, axillary nodal status, standardized pathological grade, and hormone-receptor status are accepted as established prognostic and/or predictive factors for selection of systemic adjuvant treatment of breast cancer. Yet, treatment options to date have raised almost as many questions as they have provided answers, and research today has started to focus more on natural substances and synthetic analogues as mechanisms for cell function alteration [10].
Breast cancer is considered a systemic disease due to the complex dependency on hormones and growth-factors in tumor development, progression and metastasis. The current therapeutic regimens recommended to women with breast cancer include strategies to block the synthesis and effects of these growth factors. Central to this issue is the fact that estrogens play a central role in fueling tumor growth, even in cases where tumor cells express extremely little estrogen receptor levels. The adjuvant drug Tamoxifen has caused headlines by its complex positive and negative effects. Inhibitors of aromatase (the enzyme that is responsible for the last step of estrogen synthesis from cholesterol) are the new kids on the block, and some of these appear extremely effective at lowering estrogen synthesis. However, these drugs are more complicated in their actions than first assumed. It seems pertinent to seek alternative methods of manipulating hormone synthesis and metabolism. By using nutritional and botanical intervention, it may be possible to deliver phytochemicals that lower the blood and tissue levels of endogenous estrogen, as well as its precursors and metabolites, by reducing the rate of estrogen synthesis and by increasing the clearance of estrogen.
A large number of factors play into the formation, development, and progression of breast cancer and many of them offer opportunity for intervention. Of these processes, the estrogen signaling is the focus of the present research proposal. Hormonal (estrogen) signaling may be modulated by regulating the formation, function, and excretion of estrogens. Substantial evidence supports the concept that estrogens cause breast cancer in animals and humans. Since 1896, when Sir George Beatson demonstrated that ovariectomy induced regression of mammary tumors, the aim of endocrine breast cancer therapy has been to selectively deprive the body of estrogen. Ovariectomy accomplished this by removing the gland that is the predominant source of estrogens in premenopausal women. Since the avoidance of such surgery is preferable, emphasis is devoted to the identification of specific and synergistic inhibitors of estrogen production, with little or no effect on production of other steroid hormones.
Preliminary Clinical Data
Very few data exists in the literature on synergistic effects on phyto-estrogens. Curcumin and genistein – extracts from turmeric and soy – have demonstrated a strong synergistic effect in reducing the growth-stimulation on a human breast cancer cell line by estrogenic pesticides [52]. We do have some documented cases where phyto-estrogens helped normalize female hormonal balance. Herbalist Chanchal Cabrera has positive experiences with botanical intervention on female hormone balance, as monitored by testing of progesterone, testosterone, and ß-estradiol. Most of her clients in this field have been infertile women seeking improvement of hormonal balance with the objective of becoming pregnant. Herbalist Donald Yance, author of “Herbal Medicine, Healing, and Cancer”, has positive experiences with regulating the hormonal balance using herbal mixtures for women, both in the treatment of menopause and breast cancer. The outcomes were limited to clinical performance, including survival, quality of life, and in a few cases, tumor shrinkage. However, this has never been subject to a formal study, and none of the women with breast cancer were tested specifically for estrogen levels and metabolite ratios. Also, no formal monitoring of the performance of ALL women treated with botanical estrogen deprivation regimens, have been accumulated. The present proposal aims at gaining preliminary data, to pursue this in formal clinical studies.
Future Directions
If indeed the suggested botanical intervention leads to a significant reduction in estrogen levels by affecting ratios between various estrogens, then it will be valid to examine which liver enzymes are affected, and to study the liver function in more detail.
In addition, the data generated from this study will allow us to establish criteria and study design (should the results support a desicion to pursue these issues):
¨ Does botanical intervention of estrogen metabolism have value as a neo-adjuvant therapy prior to primary surgery?
¨ Could botanical or dietary intervention be proposed for women with fibroids or fibrocystic breast disease?
¨ Does estrogen-reducing botanical intervention have a use in women who have had their ovaries removed?
¨ Can botanical intervention substitute or synergize with current pharmaceutical regimen in women with more advanced metastatic cancer?
Research Design and Methods:
We wish to conduct research to substantiate whether an estrogen-reducing effect can be achieved via botanical intervention. Based on knowledge about well-studied botanicals and their effects on the hormonal regulation, we propose a multi-faceted botanical intervention program to reduce the synthesis and increase the clearance of endogenous estrogen in women with a previous history of breast cancer. The foundation for this research proposal is not mainstream, but falls under the NCCAM mission, because the rationale is to NOT strive for a complete biochemical block of one particular process using a pharmaceutical agent, but to attempt to partially reduce multiple enzymatic and physiological processes involved in estrogen regulation, leading to a more dynamic and integrated treatment strategy. This non-pharmaceutical approach does not seek to isolate single estrogen-reducing phytoceuticals, but will study the synergistic effects between whole plants and extracts that have individually been well studied.
Study design: For the purpose of this pilot study, an open study design will be used (i.e. there will be no formal control group and no placebo product). The women will serve as their own controls, as later test results will be compared to their initial test results. In addition, since the study involves widely used clinical tests from recognized diagnostic laboratories (e.g. plasma and saliva hormones from Great Smokies Diagnostic Laboratories), these tests already have established normal values with which to compare the test results from the women in this pilot study.
We will focus on women with a previous history of breast cancer. These women will receive botanical intervention for 6 months, targeted at estrogen metabolism and liver function. During the initial 3 months, the 42 study participants will be divided into 3 groups of 14. Each group will receive a limited botanical intervention. After 3 months, all women will be evaluated, after which they all will receive the full botanical intervention for another 3 months. The hormonal parameters will be performed at the beginning of the study, (i.e. prior to botanical intervention), after 3 months (when a new regimen will be introduced), and after 6 months of treatment (i.e. 3 months with the complete cocktail). At these three time points, the patients will be asked to fill out two quality of life (QOL) questionnaires (SF-36 and EORTC QLQ-C30) to assess their subjective performance and well-being, assisted by a research nurse. At the same time they will be examined by a medical doctor and a herbalist to assess their performance objectively, according to the evaluation standards used by each health practitioner.
Patient population: Forty-two women with a previous history of breast cancer will be screened for participation. Due to our inclusion/exclusion criteria, their stage will be almost completely limited to carcinoma in situ, stage I, II and IIIA. We will NOT limit the study group to any specific histo-pathology, or type of surgical procedure for the removal of the primary tumor. We will limit the study to women in which ovaries have not been removed. By choosing to work with pre-menopausal women, with intact ovaries, and who are not on hormone therapy, we are presumably working with the population with the highest estrogen levels. This should give us a better chance of seeing an effect of the estrogen-reduction intervention protocol. Our outcome measures for this short duration pilot-study are NOT survival or recurrence, but rather an evaluation of current biochemical and physiological parameters. We will not include patients who have undergone, or are currently undergoing chemotherapy or hormone therapy. Since these strategies are recommended in cases with metastatic disease, we are thereby excluding patients with metastasis, except if they on their own have made the choice to decline this therapy, and have remained in remission for at least one year. In addition, we have chosen to exclude women with a known family history of breast cancer, as we do not wish to skew the data in this limited pilot study by including several patients with one particular genetic alteration.
Diagnosis and primary surgery
Radiation
Therapy
At least 1 year disease-free
STUDY
6 months botanical intervention
At least 3 years after delivery/nursing/birth control
TESTS
Estrogen levels and
Metabolites;
QLQ
Inclusion criteria:
Caucasian or Hispanic, Pre-menopausal, Previously undergone surgical removal of breast cancer, whether lumpectomy or mastectomy, with or without removal of lymph nodes. Not currently scheduled for surgery or radiation treatment, and not undergone any of these within the past year.
Exclusion criteria
Removal of ovaries
Past or current chemotherapy and hormone therapy, including tamoxifen and other estrogen-analogues.
Pregnancy, nursing, and/or birth control pills during the past 3 years.
A known family history or genetic predisposition for breast cancer
Smoking (due to possible toxic interaction with botanical product [53])
Requirements: The women will be asked to maintain their usual diet, nutritional supplementation, and exercise regimen with no major changes in lifestyle. These parameters will be noted for each study participant. They will be asked which herbal supplements they may be taking, and when these overlap with ingredients in our botanical intervention protocol, they will be asked to supplement only with the study intervention, and for the duration of this study to discontinue the intake of the herbs that are also part of our study. They will be asked to arrive fasting, and to avoid taking any herbal products or supplements for 12 hours prior to their appointments.
Botanical intervention of estrogen synthesis, metabolism, and clearance: Choice of botanicals was based on the criteria that sufficient quality research on each single herb or extract has documented an anti-estrogen effect. The anti-estrogen effect includes: synthesis, bio-availability metabolism and excretion of estrogen. The following herbs were chosen, based on a thorough literature study: Flax (seed), soy (isoflavones), green tea (Whole leaf), turmeric (Curcurmin extract), a modified extract from cruciferous vegetables: Diindolmethane (DIM), and Chrysin. During the initial 3 months participation, a limited regimen is given:
Group I: Flax and soy
Group II: Green tea and curcumin
Group III: DIM and Chrysin
During the last 3 months, the full protocol of all 6 plant/extracts is given to all women.
Participants will receive the following doses for their assigned periods of this study:
Flax seed: 20 grams (dry weight, 2 tbsp)/day, to be consumed soaked.
Soy: 1 gram/day of a fermented soy product where microflora have increased the content and bioavailability of isoflavones.
Green tea: 300mg extract/ day. The extract contains 80% mixed polyphenols.
Turmeric: 450mg/day of a curcumin extract, containing 95% curcuminoids.
DIM: 200 mg/day
Chrysin: 1.5 grams per day of a 95% pure extract
Flax The seed of flax is the richest known source of lignans [54], which are potent phyto-chemicals that are chemically modified by the removal of carbohydrates by microflora in the human gut [55]. The aglycone lignans are absorbed into the blood, metabolized into enterodiol and enterolactone, which are biologically active anti-oxidants [56, 57], and finally excreted via urine. The metabolites influence endogenous sex hormone production and metabolism, particularly by favorably shifting the ratio between 2-hydroxyestrogen : 16alphahydroxyestrone [58, 59]. In addition, the lignan lactones and diols are moderate inhibitors of aromatase [60].
Soy isoflavones Population studies from around the world indicate that soy products are partly responsible for the lower rates of hormone-dependent cancers in certain areas of the world [61]. In vitro and clinical studies suggest that this protective effect is due to modulation of estrofen synthesis and metabolism [62, 63]. In a small but well-controlled metabolic study, a significant shift towards 2-hydroxyestrone was found in women on a soy-rich diet [64]. One of the active phytochemicals, genistein, is a weak transcriptional activator compared to endogenous estrogen, and decreases steady state mRNA of estrogen receptor [65].
Green tea Much attention has been paid to the chemoprotective effects of green tea [66]. Population studies show a correlation between intake of green tea and cancer incidence [66-69], including breast cancer [70]. This effect may not be significant under extreme exposure to carcinogens, such as the atom bomb, as no significant protection was correlated to intake of green tea on survivors of the Hiroshima and Nakasaki bombs [71]. Separate from direct anti-cancer effects, clinical studies show that green tea has an estrogen-lowering effect in humans [Nagata 1998], and a parallel increase in SHBG [72]. The main bioactive ingredients in green tea are: epicathechin, epicathechin-3-gallate, epigallocatechin, and epigallocatechin-3-gallate. However, other bioactive and anti-cancer compounds are present, and the polyphenol fraction does not account for all biological activities of green tea. Green tea inhibits the glucoronidation of estrone and estradiol in a dose-dependent manner [73]. Epigallocatechin gallate – the main ingredient based on dry weight – affects expression of the enzyme glutathione-s-transferase [74], an enzyme that participates in processing 4-hydrozyestrone from quinines to mercapturates, which are potentially carcinogenic.
Turmeric Turmeric has a wide range of effects in relation to chemoprotection from cancer, both in vivo and in vitro, including colon, skin, and mammary tumors. Many studies have verified the anti-carcinogenic properties of turmeric. The main ingredient, Curcumin, inhibits the growth of estrogen-dependent cells in vitro [75]. One study provided data in strong support of synergistic effects of soy isoflavones and curcumin for inhibition of estrogenic effects of pesticides in a human breast cancer cell line [52, 76].
3.3′-Di-indolyl-methane (DIM) Cruciferous vegetables, including cabbage, kale, and broccoli, contain indole-3-carbinole. The gastric conversion product is DIM, which display multi-facetted activities, and is a potent inducer of cytochrome P450. It has been proposed that the protective effect against breast cancer is due to a decrease in the formation of 16alpha-hydroxyestrone [77]. DIM showed a weak inhibition of estrogen receptor function, and a ligand-independent activator of ER signaling, in an estrogen dependent human breast cancer cell line [78]. It has been shown to down-regulate estrogen receptors [40, 79], increase the 2-hydroxylation of estrogens, and decreasing the formation of the carcinogenic 4-hydroxyestrone [80]. DIM inhibits estrogen-induced proliferation in human breast cancer cell lines [40] and mammary tumor formation in rats [81]. Reports on altered toxicity of tamoxifen and nicotine in rats receiving DIM [53] warrants the exclusion of smokers and patients receiving tamoxifen in this study.
Chrysin Chrysin is an extract from the plant Passiflora Caerula. It has aromatase inhibitor activity [82], and inhibits the formation of estrogen from testosterone. It also contains potent activity in terms of induction of glucoronidation of estrogens, including estradiols [83, 84], which are involved in metabolizing estrogens for excretion via the bile.