Dietary genistein negates the inhibitory effect of letrozole on the growth of aromatase-expressing estrogen-dependent human breast cancer cells (MCF-7Ca) in vivo

Benefits of Soybean in the Era of Precision Medicine: A Review of Clinical Evidence

Soybean (Glycine max) is an important ingredient of cuisines worldwide. While there is a wealth of evidence that soybean could be a good source of macronutrients and phytochemicals with health-promoting effects, concerns regarding adverse effects have been raised. In this work, we reviewed the current clinical evidence focusing on the benefits and risks of soybean ingredients. In breast, prostate, colorectal, ovarian, and lung cancer, epidemiological studies showed an inverse association between soybean food intake and cancer risks. Soybean intake was inversely correlated with risks of type 2 diabetes mellitus (T2DM), and soy isoflavones ameliorated osteoporosis and hot flashes. Notably, soybean was one of the dietary protein sources that may reduce the risk of breast cancer and T2DM. However, soybean had adverse effects on certain types of drug treatment and caused allergies. In sum, this work provides useful considerations for planning clinical soybean research and selecting dietary protein sources for human health.

In Vitro Effects of Combining Genistein with Aromatase Inhibitors: Concerns Regarding Its Consumption during Breast Cancer Treatment

INTRODUCTION

The third-generation of aromatase inhibitors (AIs)-Exemestane (Exe), Letrozole (Let), and Anastrozole (Ana)-is the main therapeutic approach applied for estrogen receptor-positive (ER+) breast cancer (BC), the most common neoplasm in women worldwide. Despite their success, the development of resistance limits their efficacy. Genistein (G), a phytoestrogen present in soybean, has promising anticancer properties in ER+ BC cells, even when combined with anticancer drugs. Thus, the potential beneficial effects of combining G with AIs were investigated in sensitive (MCF7-aro) and resistant (LTEDaro) BC cells.

METHODS

The effects on cell proliferation and expression of aromatase, ERα/ERβ, and AR receptors were evaluated.

RESULTS

Unlike the combination of G with Ana or Let, which negatively affects the Ais' therapeutic efficacy, G enhanced the anticancer properties of the steroidal AI Exe, increasing the antiproliferative effect and apoptosis relative to Exe. The hormone targets studied were not affected by this combination when compared with Exe.

CONCLUSIONS

This is the first in vitro study that highlights the potential benefit of G as an adjuvant therapy with Exe, emphasizing, however, that soy derivatives widely used in the diet or applied as auxiliary medicines may increase the risk of adverse interactions with nonsteroidal AIs used in therapy.

The health effects of soy: A reference guide for health professionals

Soy is a hotly debated and widely discussed topic in the field of nutrition. However, health practitioners may be ill-equipped to counsel clients and patients about the use of soyfoods because of the enormous, and often contradictory, amount of research that has been published over the past 30 years. As interest in plant-based diets increases, there will be increased pressure for practitioners to gain a working knowledge of this area. The purpose of this review is to provide concise literature summaries (400-500 words) along with a short perspective on the current state of knowledge of a wide range of topics related to soy, from the cholesterol-lowering effects of soy protein to the impact of isoflavones on breast cancer risk. In addition to the literature summaries, general background information on soyfoods, soy protein, and isoflavones is provided. This analysis can serve as a tool for health professionals to be used when discussing soyfoods with their clients and patients.

Drug-Exposome Interactions: The Next Frontier in Precision Medicine

Drug-drug interactions are a known concern during medical treatment. However, in addition to therapeutic drugs, humans are exposed to thousands of environment- and food-related chemicals on a daily basis. The exposome (i.e.,the total measure of environmental factors on the human body) is an emerging concept in the field of environmental health. Many chemicals have the potential to interact with drugs and subsequently influence health outcomes. To date, this concept has not been systematicallyinvestigated. Nevertheless, adverse effects have been observed betweenenvironmental, dietary, and microbiome-derived xenobiotics and a number of drugs, including chemotherapeutics. Recent technological advances in mass spectrometry-based metabolomics and the establishment of omic-scale exposure assessment will enable a broader and systemic investigation of these interactions. As a complement to pharmacogenomics and pharmacometabolomics, research ondrug-exposome interactions holds immense potential to elevate precision medicineto an unprecedented level.

Safety of non-hormonal medications for managing hot flashes

Introduction: Menopausal complaints are a critical aspect of women's lives. In particular vasomotor symptoms, such as hot flashes, may seriously impact quality of life and are considered the most bothersome complaint by patients. Although Menopausal Hormone Therapy (MHT) is considered the best option, women increasingly ask for a natural and more tailored treatment approach.Areas covered: Nutraceutical compounds represent the most widespread alternative therapy for vasomotor symptoms, and their use is somewhat increasing. In this review, the authors analyzed the mechanism of action and the related safety of non-hormonal treatments, including new approaches and future aspects.Expert opinion: MHT represents the traditional therapy for menopausal complaints, especially for severe and moderate symptoms; however, evidence has not defined a safety profile for all patients. To address this issue, nutraceuticals could represent a compelling and useful non-hormonal approach in selected patients.

Neither soyfoods nor isoflavones warrant classification as endocrine disruptors: a technical review of the observational and clinical data

Soybeans are a rich source of isoflavones, which are classified as phytoestrogens. Despite numerous proposed benefits, isoflavones are often classified as endocrine disruptors, based primarily on animal studies. However, there are ample human data regarding the health effects of isoflavones. We conducted a technical review, systematically searching Medline, EMBASE, and the Cochrane Library (from inception through January 2021). We included clinical studies, observational studies, and systematic reviews and meta-analyses (SRMA) that examined the relationship between soy and/or isoflavone intake and endocrine-related endpoints. 417 reports (229 observational studies, 157 clinical studies and 32 SRMAs) met our eligibility criteria. The available evidence indicates that isoflavone intake does not adversely affect thyroid function. Adverse effects are also not seen on breast or endometrial tissue or estrogen levels in women, or testosterone or estrogen levels, or sperm or semen parameters in men. Although menstrual cycle length may be slightly increased, ovulation is not prevented. Limited insight could be gained about possible impacts of in utero isoflavone exposure, but the existing data are reassuring. Adverse effects of isoflavone intake were not identified in children, but limited research has been conducted. After extensive review, the evidence does not support classifying isoflavones as endocrine disruptors.

The effects of phytoestrogens on postmenopausal health

Phytoestrogens are a group of non-steroidal polyphenolic plant-based substances, commonly used for the treatment of menopause-related conditions. They have both genomic and non-genomic effects, displaying weak affinity for estrogen receptors (ER) and preferentially binding to ER-B over ER-A. However, evidence for the benefits of phytoestrogen consumption has been limited. We conducted a review of recent literature, focusing on systematic reviews and meta-analyses reporting on postreproductive health effects of phytoestrogens. While many trials concerning dietary and supplementary phytoestrogens have been conducted, evidence of clinical efficacy is heterogeneous and inconclusive. There appears to be reduction in the vasomotor symptoms of menopause with phytoestrogen intake; however, it is likely small and slow in onset. Phytoestrogens also appear to improve bone mineral density and markers of cardiovascular risk; however, there is inadequate research regarding long-term outcomes. There appear to be no harmful effects of phytoestrogens on breast, endometrial cancer or colorectal cancer and phytoestrogens intake may in fact be protective. Research regarding the effect of phytoestrogens on cognition is mixed, with most studies reporting no significant association. Overall, individual variations in the metabolism of phytoestrogens and age-related genomic effects may account for the considerable variability in the measured effects of phytoestrogens.

Predicting and Quantifying Antagonistic Effects of Natural Compounds Given with Chemotherapeutic Agents: Applications for High-Throughput Screening

Natural products have been used for centuries to treat various human ailments. In recent decades, multi-drug combinations that utilize natural products to synergistically enhance the therapeutic effects of cancer drugs have been identified and have shown success in improving treatment outcomes. While drug synergy research is a burgeoning field, there are disagreements on the definitions and mathematical parameters that prevent the standardization and proper usage of the terms synergy, antagonism, and additivity. This contributes to the relatively small amount of data on the antagonistic effects of natural products on cancer drugs that can diminish their therapeutic efficacy and prevent cancer regression. The ability of natural products to potentially degrade or reverse the molecular activity of cancer therapeutics represents an important but highly under-emphasized area of research that is often overlooked in both pre-clinical and clinical studies. This review aims to evaluate the body of work surrounding the antagonistic interactions between natural products and cancer therapeutics and highlight applications for high-throughput screening (HTS) and deep learning techniques for the identification of natural products that antagonize cancer drug efficacy.

The importance of environmental exposure on selected xenoestrogens in the pathogenesis of breast cancer

Breast cancer is one of the most common types of cancer observed in women, and in its pathogenesis, in addition to endogenous estrogens, a significant role is played by xenoestrogens, which are present in the human life environment. It is a large group of exogenous compounds of diverse structure, not produced in the human body, which imitate the action of female sex hormones, especially estrogens, and in consequence affect the hormonal balance of the body. Despite the diverse structure, their common feature is the ability to interact with estrogen receptors. In this way they change the functioning of the endocrine system and, consequently, they can induce negative changes in the human body and effects on the health of both the parental generation and its offspring. Some xenoestrogens may cause tumor growth by stimulating cell proliferation, angiogenesis and metastasis. So far, such properties have been found for organic compounds, but also for some metal ions, referred to as metalloestrogens. For this reason, it is extremely important to know the sources of the presence and mechanisms of xenoestrogens in the pathogenesis of mammary gland cancer. The presented paper discusses the role of selected xenoestrogens, such as: bisphenol A, phthalates, parabens or cadmium, as a metalloestrogen. A wide range of xenoestrogens has been selected for the compounds given above, due to their importance in the pathogenesis of breast cancer and their widespread presence in the human environment, as well as to draw attention to the still-present problem of possible chronic environmental or occupational exposure of humans. The paper also explores the problem of the effect of xenoestrogens on the efficacy of breast cancer treatment, presenting possible xenoestrogen-drug interactions. It also explains how xenoestrogens present in foods (phytoestrogens) can affect the effectiveness of pharmacotherapy of breast cancer.

Nobiletin in Cancer Therapy: How This Plant Derived-Natural Compound Targets Various Oncogene and Onco-Suppressor Pathways

Cancer therapy is a growing field, and annually, a high number of research is performed to develop novel antitumor drugs. Attempts to find new antitumor drugs continue, since cancer cells are able to acquire resistance to conventional drugs. Natural chemicals can be considered as promising candidates in the field of cancer therapy due to their multiple-targeting capability. The nobiletin (NOB) is a ubiquitous flavone isolated from Citrus fruits. The NOB has a variety of pharmacological activities, such as antidiabetes, antioxidant, anti-inflammatory, hepatoprotective, and neuroprotective. Among them, the antitumor activity of NOB has been under attention over recent years. In this review, we comprehensively describe the efficacy of NOB in cancer therapy. NOB induces apoptosis and cell cycle arrest in cancer cells. It can suppress migration and invasion of cancer cells via the inhibition of epithelial-to-mesenchymal transition (EMT) and EMT-related factors such as TGF-β, ZEB, Slug, and Snail. Besides, NOB inhibits oncogene factors such as STAT3, NF-κB, Akt, PI3K, Wnt, and so on. Noteworthy, onco-suppressor factors such as microRNA-7 and -200b undergo upregulation by NOB in cancer therapy. These onco-suppressor and oncogene pathways and mechanisms are discussed in this review.

Dietary phytochemicals in breast cancer research: anticancer effects and potential utility for effective chemoprevention

Cancerous tissue transformation developing usually over years or even decades of life is a highly complex process involving strong stressors damaging DNA, chronic inflammation, comprehensive interaction between relevant molecular pathways, and cellular cross-talk within the neighboring tissues. Only the minor part of all cancer cases are caused by inborn predisposition; the absolute majority carry a sporadic character based on modifiable risk factors which play a central role in cancer prevention. Amongst most promising candidates for dietary supplements are bioactive phytochemicals demonstrating strong anticancer effects. Abundant evidence has been collected for beneficial effects of flavonoids, carotenoids, phenolic acids, and organosulfur compounds affecting a number of cancer-related pathways. Phytochemicals may positively affect processes of cell signaling, cell cycle regulation, oxidative stress response, and inflammation. They can modulate non-coding RNAs, upregulate tumor suppressive miRNAs, and downregulate oncogenic miRNAs that synergically inhibits cancer cell growth and cancer stem cell self-renewal. Potential clinical utility of the phytochemicals is discussed providing examples for chemoprevention against and therapy for human breast cancer. Expert recommendations are provided in the context of preventive medicine.

Metabolomics Reveals that Dietary Xenoestrogens Alter Cellular Metabolism Induced by Palbociclib/Letrozole Combination Cancer Therapy

Recently, the palbociclib/letrozole combination therapy was granted accelerated US FDA approval for the treatment of estrogen receptor (ER)-positive breast cancer. Since the underlying metabolic effects of these drugs are yet unknown, we investigated their synergism at the metabolome level in MCF-7 cells. As xenoestrogens interact with the ER, we additionally aimed at deciphering the impact of the phytoestrogen genistein and the estrogenic mycotoxin zearalenone. A global metabolomics approach was applied to unravel metabolite and pathway modifications. The results clearly showed that the combined effects of palbociclib and letrozole on cellular metabolism were far more pronounced than that of each agent alone and potently influenced by xenoestrogens. This behavior was confirmed in proliferation experiments and functional assays. Specifically, amino acids and central carbon metabolites were attenuated, while higher abundances were observed for fatty acids and most nucleic acid-related metabolites. Interestingly, exposure to model xenoestrogens appeared to counteract these effects.

Effect of Soy Isoflavone on Hot Flushes, Endometrial Thickness, and Breast Clinical as well as Sonographic Features

BACKGROUND

Phytoestrogens treatment to relieve hot flushes in menopausal women was considered recently. However, the actual effectiveness and safety are not clear.

METHODS

Randomized clinical trial (IRCT#20100706004329N5) was performed in 204 patients who complained of hot flushes in Arash Women's Hospital, Tehran, Iran from 2013-2015. The first group received 50 mg isoflavone (group A) once daily and the second group received placebo (group B) in the same regimen. Patients were evaluated for breast examination (BE) and breast sonography (BS) as well as vaginal sonography at initial presentation and at 6th and 12th week follow-ups. Patients were educated to record frequency and severity of hot flushes.

RESULTS

Group A experienced less hot flushes attack (6 vs 9 patients with 5< attacks in 6 wk (P= 0.05), 7 Vs 13 patients with 5< in 12 wk (P=0.01)) which was also less severe (8 vs 12 patients with severe symptoms in 6 wk (0.04) and 3 Vs 10 patients with severe symptoms in 12 wk (0.001). Isoflavone had no effect on neither breast density nor nodularity (in 6 wk, P=0.50 and 0.80, respectively and in 12 wk, P=0.32 and 0.43) and neither breast tenderness nor nipple discharge (in 6 wk, P=0.40 and 0.34 respectively and in 12 wk, P= 0.31 and 0.26). There were no significant differences in endometrial thickness in 6 and 12wk.

CONCLUSION

Effects of isoflavone on frequency and severity of hot flushes in perimenopausal women is observed. Some clinical and ultrasonographic benign non-significant changes of the breast and endometrium are noted after isoflavone intake.

Postdiagnosis Isoflavone and Lignan Intake in Newly Diagnosed Breast Cancer Patients: Cross-Sectional Survey Shows Considerable Intake from Previously Unassessed High-Lignan Foods

BACKGROUND

Isoflavones and lignans (phytoestrogens) are dietary components with potential anticarcinogenic effects. Although the intake of isoflavones and lignans may affect breast cancer treatment and prognosis-and associations may differ by menopausal status-postdiagnosis intake data are limited.

OBJECTIVE

We aimed to describe postdiagnosis isoflavone and lignan intake in newly diagnosed breast cancer patients, examine differences by menopausal status and phytoestrogen type, and inform the assessment of diet and survival in future prognostic studies.

METHODS

Our cross-sectional study included 278 women aged 25-74 y, diagnosed with pathologically confirmed breast cancer in April-May 2010 and identified using the Ontario Cancer Registry. Intake in the previous 2 mo was assessed using questionnaires listing 17 soy and 3 high-lignan foods (flaxseed, flaxseed bread, sesame seeds), completed 71 d after breast cancer diagnosis, on average. Food consumption by menopausal status was examined. Geometric mean and median phytoestrogen intakes were estimated among all patients and in consumers only; differences by menopausal status and phytoestrogen type were assessed.

RESULTS

Among all patients, foods were similarly consumed by menopausal status and isoflavone intakes were low (median: 56 µg/d). Consumers (n = 219) had higher intakes (median isoflavones: 1808 µg/d); 7% of isoflavone and 21% of lignan consumers had intakes ≥10 mg/d. Intakes were higher in premenopausal than in postmenopausal consumers, particularly for lignans, but were not significantly different (median lignans: 4375 compared with 1863 µg/d; P = 0.07). Lignans were significantly higher than isoflavones among most consumers (postmenopausal means: 746 compared with 100 µg/d; P < 0.0001).

CONCLUSIONS

Postdiagnosis lignan intakes from 3 high-content foods may be considerable among newly diagnosed breast cancer patients, yet they have been unassessed in previous prognostic studies. The inclusion of these foods in dietary assessment methods may improve future intake estimates and the distributions on which breast cancer survival analyses are based.

Trends in botanical dietary supplement use among US adults by cancer status: The National Health and Nutrition Examination Survey, 1999 to 2014

BACKGROUND

Patients with cancer may use botanical dietary supplements (BDS) in an attempt to manage the side effects of chemotherapy, yet evidence about BDS use among patients with cancer is limited. The authors examined trends in BDS use among US adults according to cancer status and patient characteristics.

METHODS

A serial, cross-sectional study was conducted using data from the National Health and Nutrition Examination Survey from 1999 through 2014 (n = 43,644). Self-reported cancer diagnosis history and any BDS use in the preceding 30 days were determined. The prevalence of BDS use was calculated in each cycle for respondents with and without cancer, both overall and by patient characteristics. Simple linear regression models were applied to test for trends in BDS use at a 2-sided P value < .05. Multiple logistic regression models were performed to identify the patient factors associated with BDS use. The results were weighted to represent national estimates.

RESULTS

The prevalence of BDS use was greater among participants who had cancer compared with participants who did not have cancer, but trends remained stable during 1999 through 2014 for both groups. Trends in BDS use declined in patients with cancer who were older (P_trend  = .047), had a low annual family income (P_trend  = .028), and had a lower education level (P_trend  = .004). Among the respondents without cancer, trends in BDS use declined in those who were middle-aged (P_trend  = .025), non-Hispanic whites (P_trend  = .025), those with a lower education level (P_trend  = .011), and those who were not receiving prescription medication (P_trend  = .036). Patient age, sex, race/ethnicity, income, education, and health conditions were associated with BDS use.

CONCLUSIONS

The overall use of BDS remained stable during 1999 through 2014 for US adults with and without cancer, but it varied by individual characteristics. Cancer 2018;124:1207-15. © 2017 American Cancer Society.

The history and basic science development of soy isoflavones

This review summarizes the 2016 NAMS/Pfizer-Wulf H. Utian Endowed Lecture that focused on the history and basic science of soy isoflavones. Described is a personal perspective of the background and history that led to the current interest in soy and isoflavones with a specific focus on the role that soy isoflavones play in the health of postmenopausal women. This overview covers the metabolism and physiological behavior of isoflavones, their biological properties that are of potential relevance to aging, issues related to the safety of soy isoflavones, and the role of the important intestinally derived metabolite S-(-)equol.

Modulation of estrogen synthesis and metabolism by phytoestrogens in vitro and the implications for women's health

Phytoestrogens are increasingly used as dietary supplements due to their suggested health promoting properties, but also by women for breast enhancement and relief of menopausal symptoms. Generally, phytoestrogens are considered to exert estrogenic activity via estrogen receptors (ERs), but they may also affect estrogen synthesis and metabolism locally in breast, endometrial and ovarian tissues. Considering that accurate regulation of local hormone levels is crucial for normal physiology, it is not surprising that interference with hormonal synthesis and metabolism is associated with a wide variety of women's health problems, varying from altered menstrual cycle to hormone-dependent cancers. Yet, studies on phytoestrogens have mainly focused on ER-mediated effects of soy-derived phytoestrogens, with less attention paid to steroid synthesis and metabolism or other phytoestrogens. This review aims to evaluate the potential of phytoestrogens to modulate local estrogen levels and the implications for women's health. For that, an overview is provided of the effects of commonly used phytoestrogens, i.e. 8-prenylnaringenin, biochanin A, daidzein, genistein, naringenin, resveratrol and quercetin, on estrogen synthesizing and metabolizing enzymes in vitro. The potential implications for women's health are assessed by comparing the in vitro effect concentrations with blood concentrations that can be found after intake of these phytoestrogens. Based on this evaluation, it can be concluded that high-dose supplements with phytoestrogens might affect breast and endometrial health or fertility in women via the modulation of steroid hormone levels. However, more data regarding the tissue levels of phytoestrogens and effect data from dedicated, tissue-specific assays are needed for a better understanding of potential risks. At least until more certainty regarding the safety has been established, especially young women would better avoid using supplements containing high doses of phytoestrogens.

Polyphenolic Phytochemicals in Cancer Prevention and Therapy: Bioavailability versus Bioefficacy

Natural polyphenols are organic chemicals which contain phenol units in their structures. They show antitumor properties. However, a key problem is their short half-life and low bioavailability under in vivo conditions. Still, definitively demonstrating the human benefits of isolated polyphenolic compounds (alone or in combination) using modern scientific methodology has proved challenging. The most common discrepancy between experimental and clinical observations is the use of nonphysiologically relevant concentrations of polyphenols in mechanistic studies. Thus, it remains highly controversial how applicable underlying mechanisms are with bioavailable concentrations and biological half-life. The present Perspective analyses proposed antitumor mechanisms, in vivo reported antitumor effects, and possible mechanisms that may explain discrepancies between bioavailability and bioefficacy. Polyphenol metabolism and possible toxic side effects are also considered. Our main conclusion emphasizes that these natural molecules (and their chemical derivatives) indeed can be very useful, not only as cancer chemopreventive agents but also in oncotherapy.

Adding Agnus Castus and Magnolia to Soy Isoflavones Relieves Sleep Disturbances Besides Postmenopausal Vasomotor Symptoms-Long Term Safety and Effectiveness

The effectiveness for vasomotor symptoms and sleep disorders plus the long-term safety of a nutraceutical combination of agnus-castus and magnolia extracts combined with soy isoflavones (SI) and lactobacilli were assessed in postmenopausal women. A controlled study was carried out in menopausal women comparing this nutraceutical combination (ESP group) with a formulation containing isoflavones alone (C group) at the dosage recommended. The Kuppermann index, The Pittsburgh Sleep Quality Index (PSQI), and Short Form 36 (SF-36) were determined at baseline, three, six and 12 months. Endometrial thickness, mammary density and liver function were evaluated at baseline and after 12 months. One hundred and eighty women were enrolled in the study (100 in the ESP group and 80 in the C group). At the end of the treatment, mammary density, endometrial thickness, and hepatic function did not show substantial differences between groups. The Kuppermann index and particularly the tendency for hot flashes progressively and significantly decreased in frequency and severity during ESP versus C treatment. At the same time, a significant increase in sleep quality and psychophysical wellness parameters was observed in the ESP versus C groups. No adverse events were observed. Agnus-castus and magnolia, combined with SI + lactobacilli, can effectively and safely be used in symptomatic postmenopausal women, mainly when quality of sleep is the most disturbing complaint. The endometrium, mammary glands and liver function were unaffected after 12 months of treatment.

Lifetime Genistein Intake Increases the Response of Mammary Tumors to Tamoxifen in Rats

PURPOSE

Whether it is safe for estrogen receptor-positive (ER+) patients with breast cancer to consume soy isoflavone genistein remains controversial. We compared the effects of genistein intake mimicking either Asian (lifetime) or Caucasian (adulthood) intake patterns to that of starting its intake during tamoxifen therapy using a preclinical model.

EXPERIMENTAL DESIGN

Female Sprague-Dawley rats were fed an AIN93G diet supplemented with 0 (control diet) or 500 ppm genistein from postnatal day 15 onward (lifetime genistein). Mammary tumors were induced with 7,12-dimethylbenz(a)anthracene (DMBA), after which a group of control diet-fed rats were switched to genistein diet (adult genistein). When the first tumor in a rat reached 1.4 cm in diameter, tamoxifen was added to the diet and a subset of previously only control diet-fed rats also started genistein intake (post-diagnosis genistein).

RESULTS

Lifetime genistein intake reduced de novo resistance to tamoxifen, compared with post-diagnosis genistein groups. Risk of recurrence was lower both in the lifetime and in the adult genistein groups than in the post-diagnosis genistein group. We observed downregulation of unfolded protein response (UPR) and autophagy-related genes (GRP78, IRE1α, ATF4, and Beclin-1) and genes linked to immunosuppression (TGFβ and Foxp3) and upregulation of cytotoxic T-cell marker CD8a in the tumors of the lifetime genistein group, compared with controls, post-diagnosis, and/or adult genistein groups.

CONCLUSIONS

Genistein intake mimicking Asian consumption patterns improved response of mammary tumors to tamoxifen therapy, and this effect was linked to reduced activity of UPR and prosurvival autophagy signaling and increased antitumor immunity. Clin Cancer Res; 23(3); 814-24. ©2017 AACR.

Growth inhibitory effect of Scrophularia oxysepala extract on mouse mammary carcinoma 4T1 cells in vitro and in vivo systems

INTRODUCTION

Medical plants have been intensively studied as a source of antitumor compounds. In the present study, we determine the effect of Scrophularia oxysepala on triggering apoptosis and diminishing growth, size and weight of the tumor in the allograft model of Balb/c mice.

MATERIAL & METHODS

The cytotoxic effects of Scrophularia oxysepala extract on 4T1 cells were studied using MTT (3-[4,5-dimethyl-2-thiazolyl]-2, 5 diphenyl tetrazolium bromide) assay and Trypan blue staining. DNA fragmentation assay was done for apoptosis detection. After the establishment of tumor in Balb/c mice, two groups of mice were received the extract at two doses of 50 and 100mg/kg respectively using intraperitoneal injection once every two days for 28 days. In order to assess the induction of apoptosis in cancer cells, the TUNEL assay was carried out in tumoral tissues. Moreover, the Ki67 test was used to evaluate tumor proliferation.

RESULTS

According to the findings, the Scrophularia oxysepala extract inhibited cell growth. In vivo results showed that tumor size in mice treated with the extract was significantly reduced. The weight of tumor mass in treated mice after resection was less than the control group. According to the TUNEL (Terminal deoxynucleotidyl transferase dUTP nick end labeling) assay results, the herbal extract induced apoptosis in tumoral cells. Ki67 test also demonstrated that administration of the extract suppressed the growth of tumor cells.

CONCLUSION

Our data well approved the anti-proliferative effect of Scrophularia oxysepala extract, and clearly showed that, the plant extract can decrease the growth of breast cancer cells in tumor mass. Thus it may represent an ideal therapeutic tool for breast cancer.

Soy and Health Update: Evaluation of the Clinical and Epidemiologic Literature

Soyfoods have long been recognized as sources of high-quality protein and healthful fat, but over the past 25 years these foods have been rigorously investigated for their role in chronic disease prevention and treatment. There is evidence, for example, that they reduce risk of coronary heart disease and breast and prostate cancer. In addition, soy alleviates hot flashes and may favorably affect renal function, alleviate depressive symptoms and improve skin health. Much of the focus on soyfoods is because they are uniquely-rich sources of isoflavones. Isoflavones are classified as both phytoestrogens and selective estrogen receptor modulators. Despite the many proposed benefits, the presence of isoflavones has led to concerns that soy may exert untoward effects in some individuals. However, these concerns are based primarily on animal studies, whereas the human research supports the safety and benefits of soyfoods. In support of safety is the recent conclusion of the European Food Safety Authority that isoflavones do not adversely affect the breast, thyroid or uterus of postmenopausal women. This review covers each of the major research areas involving soy focusing primarily on the clinical and epidemiologic research. Background information on Asian soy intake, isoflavones, and nutrient content is also provided.

Effects of letrozole on breast cancer micro-metastatic tumor growth in bone and lung in mice inoculated with murine 4T1 cells

Breast cancer (BC) is the leading cancer in women worldwide. Metastasis occurs in stage IV BC with bone and lung being common metastatic sites. Here we evaluate the effects of the aromatase inhibitor letrozole on BC micro-metastatic tumor growth in bone and lung metastasis in intact and ovariectomized (OVX) mice with murine estrogen receptor negative (ER-) BC cells inoculated in tibia. Forty-eight BALB/c mice were randomly assigned to one of four groups: OVX, OVX + Letrozole, Intact, and Intact + Letrozole, and injected with 4T1 cells intra-tibially. Letrozole was subcutaneously injected daily for 23 days at a dose of 1.75 µg/g body weight. Tumor progression was monitored by bioluminescence imaging (BLI). Following necropsy, inoculated tibiae were scanned via µCT and bone response to tumor was scored from 0 (no ectopic mineralization/osteolysis) to 5 (extensive ectopic mineralization/osteolysis). OVX mice had higher tibial pathology scores indicative of more extensive bone destruction than intact mice, irrespective of letrozole treatment. Letrozole decreased serum estradiol levels and reduced lung surface tumor numbers in intact animals. Furthermore, mice receiving letrozole had significantly fewer tumor colonies and fewer proliferative cells in the lung than OVX and intact controls based on H&E and Ki-67 staining, respectively. In conclusion, BC-inoculated OVX animals had higher tibia pathology scores than BC-inoculated intact animals and letrozole reduced BC metastases to lungs. These findings suggest that, by lowering systemic estrogen level and/or by interacting with the host organ, the aromatase inhibitor letrozole has the potential to reduce ER- BC metastasis to lung.

Long-term soy consumption and tumor tissue MicroRNA and gene expression in triple-negative breast cancer

BACKGROUND

Soy food intake may have protective effects against the risk for breast cancer, including estrogen receptor (ER)-negative breast cancer. However, the underlying molecular mechanisms remain unclear.

METHODS

To evaluate the association of soy intake with the expression of microRNAs (miRNAs) and genes in the tumor tissue of patients with triple-negative breast cancer (TNBC; ie, breast cancer lacking expression of ER, progesterone receptor, and human epidermal growth factor receptor 2), the expression of 800 miRNAs and 302 genes were measured with NanoString nCounter assays in formalin-fixed, paraffin-embedded tumor tissue from 272 TNBC patients. Soy intake during the 1-year period before the cancer diagnosis was assessed with a validated food-frequency questionnaire. The association of soy intake with the expression of miRNAs and genes was evaluated via linear regression analysis with adjustments for patient age and TNM stage.

RESULTS

A total of 14 miRNAs and 24 genes were significantly associated with soy food intake (P < .05): Thirteen of the 14 miRNAs (92.9%) and 9 of the 24 genes (37.5%), including tumor suppressors miR-29a-3p and IGF1R, showed overexpression for those women with high soy intake, whereas the remaining miRNAs and genes, including oncogenes KRAS and FGFR4, showed underexpression. Furthermore, cell growth-related genes showed a predominantly underexpression pattern according to a comparison of tumor samples from women with high soy food intake and samples from women with lower soy food intake.

CONCLUSIONS

This study suggests that long-term prediagnosis soy intake may lead to increased expression of tumor suppressors and decreased expression of oncogenes, especially cell growth-related genes, in breast tumor tissues. Cancer 2016;122:2544-51. © 2016 American Cancer Society.

Glycone-rich Soy Isoflavone Extracts Promote Estrogen Receptor Positive Breast Cancer Cell Growth

Due to the association of hormone replacement therapy (HRT) with breast cancer risk, estrogenically active soy isoflavones are considered as an HRT alternative to alleviate menopausal symptoms. However, several recent reports challenged the health benefits of soy isoflavones and associated them with breast cancer promotion. While glyconic isoflavones are the major constituents of soybean seeds, due to their low cell permeability, they are considered to be biologically inactive. The glyconic isoflavones may exert their effects on membrane-bound estrogen receptors or could be converted to aglycones by extracellular β-glucosidases. Therefore, we hypothesized that despite their low cell permeability, soybean cultivars with high glyconic isoflavones may promote breast cancer cell growth. To test this, composition and estrogenic activity of isoflavones from 54 commercial soybean cultivars were determined. Soybean seeds produced in identical climate and growth conditions were used to minimize the effects of extraneous factors on isoflavone profile and concentrations. The glyconic daidzin concentration negatively correlated with genistin and with other aglycones. Relative to control, isoflavone extracts from 51 cultivars were estrogenic and promoted the growth of estrogen receptor positive (ER+) breast cancer cell line MCF-7 from 1.14 to 4.59 folds and other three cultivars slightly reduced the growth. Among these, extracts from three cultivars were highly estrogenic and promoted MCF-7 cell growth by 2.59-4.64 folds (P<0.005). Among six isoflavones, daidzin was positively associated with MCF-7 cell growth (P<0.005, r = 0.13966), whereas the negative correlation between genistin and MCF-7 cell growth was nearly significant (P≤0.0562, r = -0.026141). Furthermore, in drug interaction studies daidzin-rich isoflavone extracts antagonized tamoxifen, an ER inhibitor. Taken together, our results suggest that the glyconic daidzin-rich soy isoflavone extracts may exert estrogenic effects and promote ER+ breast cancer growth.

Impact of Soy Foods on the Development of Breast Cancer and the Prognosis of Breast Cancer Patients

The relationship between soy food intake and breast cancer has been rigorously investigated for more than 25 years. The identification of isoflavones as possible chemopreventive agents helped fuel this line of investigation. These diphenolic compounds, which are found in uniquely-rich amounts in soy beans, possess both estrogen-dependent and -independent properties that potentially inhibit the development of breast cancer. Observational studies show that among Asian women higher soy consumption is associated with an approximate 30% reduction in risk of developing breast cancer. However, evidence suggests that for soy to reduce breast cancer risk consumption must occur early in life, that is during childhood and/or adolescence. Despite the interest in the role of soy in reducing breast cancer risk concerns have arisen that soy foods, because they contain isoflavones, may increase the likelihood of high-risk women developing breast cancer and worsen the prognosis of breast cancer patients. However, extensive clinical and epidemiologic data show these concerns to be unfounded. Clinical trials consistently show that isoflavone intake does not adversely affect markers of breast cancer risk, including mammographic density and cell proliferation. Furthermore, prospective epidemiologic studies involving over 11,000 women from the USA and China show that postdiagnosis soy intake statistically significantly reduces recurrence and improves survival.

Endocrine resistance in breast cancer--An overview and update

Tumors that express detectable levels of the product of the ESR1 gene (estrogen receptor-α; ERα) represent the single largest molecular subtype of breast cancer. More women eventually die from ERα+ breast cancer than from either HER2+ disease (almost half of which also express ERα) and/or from triple negative breast cancer (ERα-negative, progesterone receptor-negative, and HER2-negative). Antiestrogens and aromatase inhibitors are largely indistinguishable from each other in their abilities to improve overall survival and almost 50% of ERα+ breast cancers will eventually fail one or more of these endocrine interventions. The precise reasons why these therapies fail in ERα+ breast cancer remain largely unknown. Pharmacogenetic explanations for Tamoxifen resistance are controversial. The role of ERα mutations in endocrine resistance remains unclear. Targeting the growth factors and oncogenes most strongly correlated with endocrine resistance has proven mostly disappointing in their abilities to improve overall survival substantially, particularly in the metastatic setting. Nonetheless, there are new concepts in endocrine resistance that integrate molecular signaling, cellular metabolism, and stress responses including endoplasmic reticulum stress and the unfolded protein response (UPR) that provide novel insights and suggest innovative therapeutic targets. Encouraging evidence that drug combinations with CDK4/CDK6 inhibitors can extend recurrence free survival may yet translate to improvements in overall survival. Whether the improvements seen with immunotherapy in other cancers can be achieved in breast cancer remains to be determined, particularly for ERα+ breast cancers. This review explores the basic mechanisms of resistance to endocrine therapies, concluding with some new insights from systems biology approaches further implicating autophagy and the UPR in detail, and a brief discussion of exciting new avenues and future prospects.

Non-clinical toxicity studies on bioactive compounds within the framework of nutritional and health claims

The growing presence of products on the market with added value in terms of health makes essential their regulation and harmonization in critical aspects such as safety. The toxicology applied to the bioactive compounds should demonstrate the absence of toxic effects at doses advised for consumption, as well as evaluate the potential toxic effects in the assumption that the products are used in quantities superior to those recommended. The specific strategy should be defined case by case; therefore, prior to any toxicological development, it is essential to study all the information regarding the bioactive compounds (BACs) characterization, nutridynamics and nutrikinetics, that is available. In this guideline, a general strategy to be applied in the development of BACs is proposed. It includes a first in vitro phase to discard genotoxicity and endocrine effects and a second in vivo phase with different possibilities regarding the duration and the extension of the studies.

A systematic review of non-hormonal treatments of vasomotor symptoms in climacteric and cancer patients

The cardinal climacteric symptoms of hot flushes and night sweats affect 24-93% of all women during the physiological transition from reproductive to post-reproductive life. Though efficacious, hormonal therapy and partial oestrogenic compounds are linked to a significant increase in breast cancer. Non-hormonal treatments are thus greatly appreciated.

This systematic review of published hormonal and non-hormonal treatments for climacteric, and breast and prostate cancer-associated hot flushes, examines clinical efficacy and therapy-related cancer risk modulation.

A PubMed search included literature up to June 19, 2014 without limits for initial dates or language, with the search terms, (hot flush* OR hot flash*) AND (clinical trial* OR clinical stud*) AND (randomi* OR observational) NOT review). Retrieved references identified further papers. The focus was on hot flushes; other symptoms (night sweats, irritability, etc.) were not specifically screened. Included were some 610 clinical studies where a measured effect of the intervention, intensity and severity were documented, and where patients received treatment of pharmaceutical quality. Only 147 of these references described studies with alternative non-hormonal treatments in post-menopausal women and in breast and prostate cancer survivors; these results are presented in Additional file 1.

The most effective hot flush treatment is oestrogenic hormones, or a combination of oestrogen and progestins, though benefits are partially outweighed by a significantly increased risk for breast cancer development.

This review illustrates that certain non-hormonal treatments, including selective serotonin reuptake inhibitors, gabapentin/pregabalin, and Cimicifuga racemosa extracts, show a positive risk-benefit ratio.

Key points

Several non-hormonal alternatives to hormonal therapy have been established and registered for the treatment of vasomotor climacteric symptoms in peri- and post-menopausal women.

There are indications that non-hormonal treatments are useful alternatives in patients with a history of breast and prostate cancer. However, confirmation by larger clinical trials is required.

Toxic phytochemicals and their potential risks for human cancer

Consuming plants for their presumed health benefits has occurred since early civilizations. Phytochemicals are found in various plants that are frequently included in the human diet and are generally thought to be safe for consumption because they are produced naturally. However, this is not always the case and in fact many natural compounds found in several commonly consumed plants are potential carcinogens or tumor promoters and should be avoided.

Coadministrating luteolin minimizes the side effects of the aromatase inhibitor letrozole

Aromatase inhibitors (AIs) have been used as adjuvant therapeutic agents for breast cancer. Their adverse side effect on blood lipid is well documented. Some natural compounds have been shown to be potential AIs. In the present study, we compared the efficacy of the flavonoid luteolin to the clinically approved AI letrozole (Femara; Novartis Pharmaceuticals, East Hanover, NJ) in a cell and a mouse model. In the in vitro experimental results for aromatase inhibition, the Ki values of luteolin and letrozole were estimated to be 2.44 µM and 0.41 nM, respectively. Both letrozole and luteolin appeared to be competitive inhibitors. Subsequently, an animal model was used for the comparison. Aromatase-expressing MCF-7 cells were transplanted into ovariectomized athymic mice. Luteolin was given by mouth at 5, 20, and 50 mg/kg, whereas letrozole was administered by intravenous injection. Similar to letrozole, luteolin administration reduced plasma estrogen concentrations and suppressed the xenograft proliferation. The regulation of cell cycle and apoptotic proteins-such as a decrease in the expression of Bcl-xL, cyclin-A/D1/E, CDK2/4, and increase in that of Bax-was about the same in both treatments. The most significant disparity was on blood lipids. In contrast to letrozole, luteolin increased fasting plasma high-density lipoprotein concentrations and produced a desirable blood lipid profile. These results suggested that the flavonoid could be a coadjuvant therapeutic agent without impairing the action of AIs.

Soy foods, isoflavones, and the health of postmenopausal women

Over the past 2 decades, soy foods have been the subject of a vast amount of research, primarily because they are uniquely rich sources of isoflavones. Isoflavones are classified as both phytoestrogens and selective estrogen receptor modulators. The phytoestrogenic effects of isoflavones have led some to view soy foods and isoflavone supplements as alternatives to conventional hormone therapy. However, clinical research shows that isoflavones and estrogen exert differing effects on a variety of health outcomes. Nevertheless, there is substantial evidence that soy foods have the potential to address several conditions and diseases associated with the menopausal transition. For example, data suggest that soy foods can potentially reduce ischemic heart disease through multiple mechanisms. Soy protein directly lowers blood low-density lipoprotein-cholesterol concentrations, and the soybean is low in saturated fat and a source of both essential fatty acids, the omega-6 fatty acid linoleic acid and the omega-3 fatty acid alpha-linolenic acid. In addition, soflavones improve endothelial function and possibly slow the progression of subclinical atherosclerosis. Isoflavone supplements also consistently alleviate menopausal hot flashes provided they contain sufficient amounts of the predominant soybean isoflavone genistein. In contrast, the evidence that isoflavones reduce bone loss in postmenopausal women is unimpressive. Whether adult soy food intake reduces breast cancer risk is unclear. Considerable evidence suggests that for soy to reduce risk, consumption during childhood and/or adolescence is required. Although concerns have been raised that soy food consumption may be harmful to breast cancer patients, an analysis in 9514 breast cancer survivors who were followed for 7.4 y found that higher postdiagnosis soy intake was associated with a significant 25% reduction in tumor recurrence. In summary, the clinical and epidemiologic data indicate that adding soy foods to the diet can contribute to the health of postmenopausal women.

Commonly used methods of complementary medicine in the treatment of breast cancer

Many patients with cancer look for information on complementary or alternative medicine (CAM) and use various CAM methods. Women with breast cancer are amongst the most avid users. Patients in Europe prefer drug-bound CAM methods, which are prone to side effects and drug interactions. In order to reduce these risks, communication between the patient and the physician on CAM is indispensible. Yet, most patients do not discuss CAM in general and complementary drug therapy in particular with their oncologists and most oncologists themselves are not overly familiar with the topic. This article gives an overview on the most often used CAM methods with regard to breast cancer. The current state of the scientific evidence, the benefits and risks are summarized.

Long-term exposure to dietary sources of genistein induces estrogen-independence in the human breast cancer (MCF-7) xenograft model

SCOPE

The long-term effect of exposure to relevant dietary levels of genistein (GEN) on estrogen receptor-positive (ER+) human breast cancer (MCF-7) progression after GEN withdrawal in athymic mice xenograft model was studied.

MATERIALS AND METHODS

Feeding studies were conducted to determine the estrogenic effect of diets on MCF-7 tumor growth: (1) implantation (19 weeks) and withdrawal (6 weeks) of 17β-estradiol (E2 ); (2) dietary GEN 500 and 750 ppm during treatment/withdrawal for 23/10 and 15/9 weeks, respectively; and, (3) dietary soy protein isolate (SPI) containing GEN 180 ppm for 31/9 weeks of treatment/withdrawal. MCF-7 tumors grew fast in the presence of E2 implantation and abruptly regressed completely after E2 withdrawal. At different rates, dietary GEN alone (500 and 750 ppm) and GEN (180 ppm)-containing SPI stimulated MCF-7 tumor growth. After removal of the stimulus diet, tumors induced by 750 ppm GEN, but not 500 ppm GEN or SPI, regressed completely. The protein expression of epidermal growth factor receptor 2 (HER2) was higher in the GEN- and SPI-induced nonregressing (GINR) tumors compared to MCF-7 and E2 controls.

CONCLUSION

Long-term consumption of low GEN doses (≤500 ppm) promotes MCF-7 tumor growth and results in GINR tumors with more aggressive and advanced growth phenotypes.

Post-diagnosis soy food intake and breast cancer survival: a meta-analysis of cohort studies

BACKGROUND AND OBJECTIVES

Data on associations between soy food intake after cancer diagnosis with breast cancer survival are conflicting, so we conducted this meta-analysis for more accurate evaluation.

METHODS

Comprehensive searches were conducted to find cohort studies of the relationship between soy food intake after cancer diagnosis and breast cancer survival. Data were analyzed with comprehensive meta-analysis software.

RESULTS

Five cohort studies (11,206 patients) were included. Pooling all comparisons, soy food intake after diagnosis was associated with reduced mortality (HR 0.85, 95%CI 0.77 0.93) and recurrence (HR 0.79, 95%CI 0.72 0.87). Pooling the comparisons of highest vs. lowest dose, soy food intake after diagnosis was again associated with reduced mortality (HR 0.84, 95%CI 0.71 0.99) and recurrence (HR 0.74, 95%CI 0.64 0.85). Subgroup analysis of ER status showed that soy food intake was associated with reduced mortality in both ER negative (highest vs. lowest: HR 0.75, 95%CI 0.64 0.88) and ER positive patients (highest vs. lowest: HR 0.72, 95%CI 0.61 0.84), and both premenopausal (highest vs. lowest: HR 0.78, 95%CI 0.69 0.88) and postmenopausal patients (highest vs. lowest: HR 0.81, 95%CI 0.73 0.91). In additioin, soy food intake was associated with reduced recurrence in ER negative (highest vs. lowest: HR 0.64, 95%CI 0.44 0.94) and ER+/PR+ (highest vs. lowest: HR 0.65, 95%CI 0.49 0.86), and postmenopausal patients (highest vs. lowest: HR 0.67, 95%CI 0.56 0.80).

CONCLUSION

Our meta- analysis showed that soy food intake might be associated with better survival, especially for ER negative, ER+/ PR+, and postmenopausal patients.

Drug interactions and the pharmacist: focus on everolimus

OBJECTIVE

To evaluate everolimus drug-drug and drug-food interactions, with an emphasis on patients with cancer.

DATA SOURCES

Literature was accessed through PubMed (1990-March 2013) using Boolean combinations of the terms drug interactions, herb-drug interactions, food-drug interactions, everolimus, antineoplastic agents, hormonal, and breast neoplasms. In addition, reference citations from publications and the prescribing information for everolimus were reviewed.

STUDY SELECTION AND DATA EXTRACTION

All articles published in English, including human, animal, and in vitro studies, identified from the data sources were included.

DATA SYNTHESIS

Patients with cancer are at increased risk for drug interactions because of the multiple medications they are prescribed to treat their disease and comorbid conditions. Everolimus, an oral mammalian target of rapamycin (mTOR) inhibitor, is indicated for the treatment in adults with progressive neuroendocrine tumors of pancreatic origin that are unresectable, locally advanced, or metastatic; adults with advanced renal cell carcinoma after failure of treatment with sunitinib or sorafenib; and, recently, postmenopausal women with advanced hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer in combination with exemestane after failure of treatment with letrozole or anastrozole. As its use increases among patients with cancer, clinicians must be knowledgeable about potential drug and/or food/nutrient interactions and the mechanisms by which these interactions occur, to mitigate and prevent unwanted reactions and ensure patient safety.

CONCLUSIONS

Everolimus is a widely used oral mTOR inhibitor that has the potential for drug interactions that may affect therapeutic outcomes, produce toxicities, or both. This article provides a review of evidence-based literature, along with the prescribing information, to educate clinicians on the significance of these drug interactions and their impact on management with everolimus.

Effects of steroidal aromatase inhibitors on sensitive and resistant breast cancer cells: aromatase inhibition and autophagy

Several therapeutic approaches are used in estrogen receptor positive (ER(+)) breast cancers, being one of them the use of aromatase inhibitors (AIs). Although AIs demonstrate higher efficacy than tamoxifen, they can also exhibit de novo or acquired resistance after prolonged treatment. Recently, we have described the synthesis and biochemical evaluation of four steroidal AIs, 3β-hydroxyandrost-4-en-17-one (1), androst-4-en-17-one (12), 4α,5α-epoxyandrostan-17-one (13a) and 5α-androst-2-en-17-one (16), obtained from modifications in the A-ring of the aromatase substrate, androstenedione. In this study, it was investigated the biological effects of these AIs in different breast cancer cell lines, an ER(+) aromatase-overexpressing human breast cancer cell line (MCF-7aro cells), an estrogen-receptor negative (ER(-)) human breast cancer cell line (SK-BR-3 cells), and a late stage of acquired resistance cell line (LTEDaro cells). The effects of an autophagic inhibitor (3-methyladenine) plus AIs 1, 12, 13a or exemestane in LTEDaro cells were also studied to understand the involvement of autophagy in AI acquired resistance. Our results showed that these steroids inhibit aromatase of MCF-7aro cells and decrease cell viability in a dose- and time-dependent manner. The new AI 1 is the most potent inhibitor, although the AI 12 demonstrates to be the most effective in decreasing cell viability. Besides, and in advantage over exemestane, AIs 12 and 13a also reduced LTEDaro cells viability. The use of the autophagic inhibitor allowed AIs to diminish viability of LTEDaro cells, presenting a similar behavior to the sensitive cells. Thus, inhibition of autophagy may sensitize hormone-resistant cancer cells to anti-estrogen therapies.

Time course of arthralgia among women initiating aromatase inhibitor therapy and a postmenopausal comparison group in a prospective cohort

BACKGROUND

More than 80,000 postmenopausal breast cancer patients in the United States each year are estimated to begin a 5-year course of aromatase inhibitors (AIs) to prevent recurrence. AI-related arthralgia (joint pain and/or stiffness) may contribute to nonadherence, but longitudinal data are needed on arthralgia risk factors, trajectories, and background in postmenopause. This study sought to describe 1-year arthralgia trajectories and baseline covariates among patients with AI and a postmenopausal comparison group.

METHODS

Patients initiating AIs (n = 91) were surveyed at the time of AI initiation and at 6 repeated assessments over 1 year. A comparison group of postmenopausal women without breast cancer (n = 177) completed concomitantly timed surveys. Numeric rating scales (0-10) were used to measure pain in 8 joint pair groups (bilateral fingers, wrists, elbows, shoulders, hips, knees, ankles, and toes). Poisson regression models were used to analyze arthralgia trajectories and risk factors.

RESULTS

By week 6, the AI-initiating group had more severe arthralgia than did the comparison group (ratio of means = 1.8, 95% confidence interval = 1.24-2.7, P = .002), adjusting for baseline characteristics. Arthralgia then worsened further over 1 year in the AI group. Menopausal symptom severity and existing joint-related comorbidity at baseline among women initiating AI were associated with more severe arthralgia over time.

CONCLUSIONS

Patients initiating AI should be told about the timing of arthralgia over the first year of therapy, and advised that it does not appear to resolve over the course of a year. Menopausal symptoms and joint-related comorbidity at AI initiation can help identify patients at risk for developing AI-related arthralgia.

Phytoestrogens in menopausal supplements induce ER-dependent cell proliferation and overcome breast cancer treatment in an in vitro breast cancer model

Breast cancer treatment by the aromatase inhibitor Letrozole (LET) or Selective Estrogen Receptor Modulator Tamoxifen (TAM) can result in the onset of menopausal symptoms. Women often try to relieve these symptoms by taking menopausal supplements containing high levels of phytoestrogens. However, little is known about the potential interaction between these supplements and breast cancer treatment, especially aromatase inhibitors. In this study, interaction of phytoestrogens with the estrogen receptor alpha and TAM action was determined in an ER-reporter gene assay (BG1Luc4E2 cells) and human breast epithelial tumor cells (MCF-7). Potential interactions with aromatase activity and LET were determined in human adrenocorticocarcinoma H295R cells. We also used the previously described H295R/MCF-7 co-culture model to study interactions with steroidogenesis and tumor cell proliferation. In this model, genistein (GEN), 8-prenylnaringenin (8PN) and four commercially available menopausal supplements all induced ER-dependent tumor cell proliferation, which could not be prevented by physiologically relevant LET and 4OH-TAM concentrations. Differences in relative effect potencies between the H295R/MCF-7 co-culture model and ER-activation in BG1Luc4E2 cells, were due to the effects of the phytoestrogens on steroidogenesis. All tested supplements and GEN induced aromatase activity, while 8PN was a strong aromatase inhibitor. Steroidogenic profiles upon GEN and 8PN exposure indicated a strong inhibitory effect on steroidogenesis in H295R cells and H295R/MCF-7 co-cultures. Based on our in vitro data we suggest that menopausal supplement intake during breast cancer treatment should better be avoided, at least until more certainty regarding the safety of supplemental use in breast cancer patients can be provided.

Endometrial, breast and liver safety of soy isoflavones plus Lactobacillus sporogenes in post-menopausal women

OBJECTIVE

To assess the safety of a nutraceutical compound containing soy isoflavones and Lactobacillus sporogenes on endometrium, breast and liver function.

SETTING

Outpatient Menopausal Clinic.

STUDY DESIGN

130 healthy postmenopausal women suffering from menopausal symptoms were randomized to receive soy isoflavones 60 mg and Lactobacillus sporogenes 1 billion spores (group E: 65 women) or calcium and vitamin D₃ (group C: 65 women). Safety of the treatment was assessed at baseline and after 1 year taking into account endometrial thickness, mammographic density, serum levels of transaminases, γ-GT and bilirubin. Efficacy of the treatment was evaluated rating the score of menopausal symptoms at baseline and every 3 months. The statistical analysis was carried out with χ², Fisher exact's test and ANOVA.

RESULTS

After 12 months of treatment mammographic density, endometrial thickness and hepatic function did not show significant differences between groups, while menopausal symptoms were progressively and significantly reduced in severity and frequency during treatment with soy isoflavones plus Lactobacillus sporogenes versus calcium plus vitamin D₃.

CONCLUSION

A 12 months treatment with a nutraceutical compound based on isoflavones and Lactobacillus sporogenes at the recommended doses is safe for endometrium, mammary glands and liver function in postmenopausal women.

Can breast cancer patients use soyafoods to help reduce risk of CHD?

Over the past 20 years, the popularity of soyafoods has increased in part because of research suggesting that these foods convey health benefits independent of their nutrient content. For example, in 1999, the US Food and Drug Administration approved a health-claim for soyafoods and CHD based on the hypocholesterolaemic effects of soya protein. However, soyafoods have become controversial in recent years because of concerns that their uniquely rich phyto-oestrogen (isoflavone) content may cause untoward effects in some individuals. Most notable in this regard is the concern that soyafoods are contraindicated for breast cancer patients and women at high risk of developing this disease. Furthermore, the hypocholesterolaemic effects of soya protein have been challenged. However, the results of recently published meta-analyses indicate that soya protein directly lowers circulating LDL-cholesterol levels by approximately 4 %. There is also intriguing evidence that soyafoods reduce CHD risk independent of their effects on lipid levels. In regard to the breast cancer controversy, recently published clinical and epidemiological data do not support observations in rodents that soyabean isoflavones increase breast cancer risk. In postmenopausal women, isoflavone exposure does not adversely affect breast tissue density or breast cell proliferation. Furthermore, both US and Chinese prospective epidemiological studies show that post-diagnosis soya consumption is associated with an improved prognosis. Therefore, soyafoods should be considered by women as healthy foods to include in diets aimed at reducing the risk of CHD regardless of their breast cancer status.