Short-term soy isoflavone intervention in patients with localized prostate cancer: a randomized, double-blind, placebo-controlled trial

Effects of natural extract interventions in prostate cancer: A systematic review and network meta-analysis

BACKGROUND

Over years, there has been a widespread quest for effective dietary patterns and natural extracts to mitigate prostate cancer risk. However, despite numerous experimental studies conducted on various natural extracts, the evidence substantiating their efficacy remains largely insufficient. This dearth of compelling evidence presents a significant challenge in advocating for their widespread use as preventive measures against prostate cancer.

OBJECTIVE

Our study endeavors to undertake a network meta-analysis to evaluate the influence of natural extracts on prostate cancer.

METHODS

Researchers systematically searched through Embase, PubMed, Cochrane Library, and Web of Science databases until December 2023. The main focus was on assessing primary outcomes comprising prostate-specific antigen (PSA), insulin-like growth factor-binding protein-3 (IGFBP-3), insulin-like growth factor-1 (IGF-1). We conducted data analysis utilizing StataMP 15.0 software. Therapeutic effects were ranked based on the probability values derived from Surface Under the Cumulative Ranking curve (SUCRA). Additionally, cluster analysis was employed to assess the impacts of natural extracts on three distinct outcomes.

RESULTS

Following screening procedures, the 28 eligible studies were incorporated, the selected studies encompassed 1,566 prostate cancer patients and evaluated 16 different natural extract treatments. Specifically, 24 trials included PSA indicators, 10 included IGF-1 indicators, and 8 included IGFBP-3 indicators. The findings revealed that, based on the SUCRA values, the combined therapy of silybin with selenium (74%) appears to be the most effective approach for reducing serum PSA levels. Simultaneously, silybin alone (84.6%) stands out as the most promising option for decreasing serum IGF-1 levels. Lastly, concerning IGFBP-3, silybin alone (67.7%) emerges as the optimal choice. Twelve studies provided comprehensive information on adverse drug reactions/events (ADR/ADE), whereas five articles did not report any significant ADR/ADE.

CONCLUSION

The NMA suggests that, compared to placebo, utilizing silybin either alone or in combination with selenium has been shown to enhance therapeutic effects, offering potential benefits to patients with prostate cancer. This study can offer valuable insights for prostate patients considering natural extract treatments. Further evidence is required to confirm the safety profile of these treatments.

The effect of a fermented soy beverage among patients with localized prostate cancer prior to radical prostatectomy

BACKGROUND

Fermented soy products have shown to possess inhibitory effects on prostate cancer (PCa). We evaluated the effect of a fermented soy beverage (Q-Can®), containing medium-chain triglycerides, ketones and soy isoflavones, among men with localized PCa prior to radical prostatectomy.

METHODS

We conducted a placebo-controlled, double-blind randomized trial of Q-Can®. Stratified randomization (Cancer of the Prostate Risk Assessment (CAPRA) score at diagnosis) was used to assign patients to receive Q-Can® or placebo for 2-5 weeks before RP. Primary endpoint was change in serum PSA from baseline to end-of-study. We assessed changes in other clinical and pathologic endpoints. The primary ITT analysis compared PSA at end-of-study between randomization arms using repeated measures linear mixed model incorporating baseline CAPRA risk strata.

RESULTS

We randomized 19 patients, 16 were eligible for analysis of the primary outcome. Mean age at enrollment was 61, 9(56.2%) were classified as low and intermediate risk, and 7(43.8%) high CAPRA risk. Among patients who received Q-Can®, mean PSA at baseline and end-of-study was 8.98(standard deviation, SD 4.07) and 8.02ng/mL(SD 3.99) compared with 8.66(SD 2.71) to 9.53ng/mL(SD 3.03), respectively, (Difference baseline - end-of-study, p = 0.36). There were no significant differences in Gleason score, clinical stage, surgical margin status, or CAPRA score between treatment arms (p > 0.05), and no significant differences between treatment arms in end-of-study or change in lipids, testosterone and FACT-P scores (p > 0.05).

CONCLUSIONS

Short exposure to Q-Can® among patients with localized PCa was not associated with changes in PSA levels, PCa characteristics including grade and stage or serum testosterone. Due to early termination from inability to recruit, study power, was not achieved.

Soy-derived isoflavones as chemo-preventive agents targeting multiple signalling pathways for cancer prevention and therapy

The chemopreventive and chemotherapeutic properties of soy and soy-derived compounds, especially isoflavones, have been extensively studied in recent years. However, in contrast to their anticancer effects, such as cell growth inhibition, cell cycle arrest and apoptosis induction, isoflavones have also been found to promote the growth of cancer cells. Therefore, the aim of this comprehensive review article is to present the current state of knowledge regarding the molecular mechanisms by which soy-derived isoflavones target multiple cellular signalling pathways in cancer cells. Our findings indicate that soy-derived isoflavones act as, among other things, potent modulators of HOX transcript antisense RNA (HOTAIR)/SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1), vascular endothelial growth factor (VEGF)/C-X-C motif chemokine ligand 12 (CXCL12)/C-X-C motif chemokine receptor type 4 (CXCR4), 17-β-oestradiol (E2)/oestrogen receptor-α (ERα)/neuroglobin (NGB) and sonic hedgehog signalling pathways, epigenetic modulatory agents (i.a. miR-155, miR-34a and miR-10a-5p) and cancer stem cells and epithelial-to-mesenchymal transition inhibitors. The paper also discusses the latest epidemiological studies and clinical trials and provides an insight into recent extensive research on the chemo-preventive and therapeutic potential of soy-derived isoflavones.

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.

The influence of lifestyle changes (diet, exercise and stress reduction) on prostate cancer tumour biology and patient outcomes: A systematic review

Background

The mostly indolent natural history of prostate cancer (PCa) provides an opportunity for men to explore the benefits of lifestyle interventions. Current evidence suggests appropriate changes in lifestyle including diet, physical activity (PA) and stress reduction with or without dietary supplements may improve both disease outcomes and patient's mental health.

Objective

This article aims to review the current evidence on the benefits of all lifestyle programmes for PCa patients including those aimed at reducing obesity and stress, explore their affect on tumour biology and highlight any biomarkers that have clinical utility.

Evidence acquisition

Evidence was obtained from PubMed and Web of Science using keywords for each section on the affects of lifestyle interventions on (a) mental health, (b) disease outcomes and (c) biomarkers in PCa patients. PRISMA guidelines were used to gather the evidence for these three sections (15, 44 and 16 publications, respectively).

Evidence synthesis

For lifestyle studies focused on mental health, 10/15 demonstrated a positive influence, although for those programmes focused on PA it was 7/8. Similarly for oncological outcomes, 26/44 studies demonstrated a positive influence, although when PA was included or the primary focus, it was 11/13. Complete blood count (CBC)-derived inflammatory biomarkers show promise, as do inflammatory cytokines; however, a deeper understanding of their molecular biology in relation to PCa oncogenesis is required (16 studies reviewed).

Conclusions

Making PCa-specific recommendations on lifestyle interventions is difficult on the current evidence. Nevertheless, notwithstanding the heterogeneity of patient populations and interventions, the evidence that dietary changes and PA may improve both mental health and oncological outcomes is compelling, especially for moderate to vigorous PA. The results for dietary supplements are inconsistent, and although some biomarkers show promise, significantly more research is required before they have clinical utility.

Insight into the Biological Roles and Mechanisms of Phytochemicals in Different Types of Cancer: Targeting Cancer Therapeutics

Cancer is a hard-to-treat disease with a high reoccurrence rate that affects health and lives globally. The condition has a high occurrence rate and is the second leading cause of mortality after cardiovascular disorders. Increased research and more profound knowledge of the mechanisms contributing to the disease’s onset and progression have led to drug discovery and development. Various drugs are on the market against cancer; however, the drugs face challenges of chemoresistance. The other major problem is the side effects of these drugs. Therefore, using complementary and additional medicines from natural sources is the best strategy to overcome these issues. The naturally occurring phytochemicals are a vast source of novel drugs against various ailments. The modes of action by which phytochemicals show their anti-cancer effects can be the induction of apoptosis, the onset of cell cycle arrest, kinase inhibition, and the blocking of carcinogens. This review aims to describe different phytochemicals, their classification, the role of phytochemicals as anti-cancer agents, the mode of action of phytochemicals, and their role in various types of cancer.

The effect of a phytoestrogen intervention and impact of genetic factors on tumor proliferation markers among Swedish patients with prostate cancer: study protocol for the randomized controlled PRODICA trial

BACKGROUND

A high intake of phytoestrogens, found in soy, rye, and seeds, is associated with a reduced risk of a prostate cancer diagnosis. Previously, we found that the overall decreased risk of prostate cancer diagnosis in males with a high intake of phytoestrogens was strongly modified by a nucleotide sequence variant in the estrogen receptor-beta (ERβ) gene. However, we do not know if phytoestrogens can inhibit the growth of prostate cancer in males with established diseases. If there is an inhibition or a delay, there is reason to believe that different variants of the ERβ gene will modify the effect. Therefore, we designed an intervention study to investigate the effect of the addition of foods high in phytoestrogens and their interaction with the ERβ genotype on prostate tumor proliferation in patients with prostate cancer.

METHOD

The PRODICA trial is a randomized ongoing intervention study in patients with low- and intermediate-risk prostate cancer with a Gleason score < 8, prostate-specific antigen (PSA) < 20, and scheduled for radical prostatectomy. The study is conducted at Sahlgrenska University Hospital in Gothenburg, Sweden. The intervention consists of a daily intake of soybeans and flaxseeds (~ 200 mg of phytoestrogens) until the surgery, approximately 6 weeks. The aim is to recruit 200 participants. The primary outcome is the difference in the proliferation marker Ki-67 between the intervention and the control groups. The genotype of ERβ will be investigated as an effect-modifying factor. Secondary outcomes include, e.g., concentrations of PSA and steroid hormones in the blood.

DISCUSSION

The results of the PRODICA trial will contribute important information on the relevance of increasing the intake of phytoestrogens in patients with prostate cancer who want to make dietary changes to improve the prognosis of their cancer. If genetic factors turn out to influence the effect of the intervention diet, dietary advice can be given to patients who most likely benefit from it. Dietary interventions are cost-effective, non-invasive, and result in few mild side effects. Lastly, the project will provide basic pathophysiological insights which could be relevant to the development of treatment strategies for patients with prostate cancer.

TRIAL REGISTRATION

CLINICALTRIALS

gov NCT02759380. Registered on 3 May 2016.

Botanicals in health and disease of the testis and male fertility: A scoping review

BACKGROUND

Male factor infertility often results from testicular disorders leading to inadequate sperm quantity and quality. Both beneficial and detrimental effects of botanical products, especially herbal medicines, on testicular functions and male fertility have been reported in the literature.

PURPOSE

This scoping review aims to map the main clinical evidence on different impacts of botanical entities on the testis and to critically appraise relevant randomized controlled trials (RCTs) published in the recent 5 years, so as to inform the future.

METHODS

Systematic reviews, meta-analyses and RCT reports on botanical impacts on testicular functions and male fertility were retrieved and synthesized from Pubmed, Web of Science, Scopus, Embase, ProQuest, Cochrane Library and Google Scholar up to 10th May 2022. RCTs published since 2018 were critically appraised against good practice guidelines for RCT and for reporting herbal studies.

RESULTS

We identified 24 systematic reviews and meta-analyses published since 2005, by authors from Iran (25%), China (21%), USA (12.5%) and 9 other countries. All but two were published in English. Only 3 systematic review protocols were identified, all published in English from China in the recent 3 years. We identified 125 RCTs published in six languages, mainly English (55%) and Chinese (42%). They were published since 1994 from 23 countries on all the six inhabitable continents, with China (46%), Australia (8%), USA (8%), India (7%) and Iran (5%) being the leading contributors. 72% and 28% RCTs published in English were on efficacy (botanicals vs placebo) and comparative effectiveness (a botanical vs other treatments), respectively. In contrast, 98% RCT reports in Chinese were on comparative effectiveness, with merely 2% on efficacy. Among all the 125 RCTs, 57% were studies in patients with semen abnormality and/or male infertility, 22% investigated herbal effects in healthy men, 14% were on patients with male sexual dysfunction and hypogonadism, and 7% were conducted in men with non-sexual disorders. Since 2018, 32 RCTs have been published, in English (69%) or Chinese (31%). Nineteen RCT reports from China, India, Japan and Korea all studied herbal formulae while the 13 RCT reports from Australia, Brazil, Czech and Italy, Iran, Malaysia, Spain, the UK and the USA all exclusively studied extracts of a single species. Putting geo-cultural differences aside, gossypol and extracts of Tripterygium wilfordii Hook. f. were found to be detrimental to the testis and male fertility, while the extracts of Withania somnifera (L.) Dunal and traditional Chinese medicine Qilin Pill, etc., might improve testosterone levels and semen parameters, thus could be therapeutic for male sexual dysfunction and infertility. However, all still require further evaluation in view of recurring weaknesses in quality control of herbal materials, RCT design and reporting. For example, only 9%-23% of the RCTs published since 2018 provided information on voucher samples, chemical profiling, herbal authentication and herbal extraction.

CONCLUSION

Research on botanicals and the testis has been reported worldwide, demonstrating clear geo-cultural differences in studied plant species, botanical types, study objectives and quality of research design, implementation and reporting. Due to a few recurring weaknesses in the literature, this study is unable to recommend the use of any specific botanicals, however, current evidence does indicate that botanicals can be double-edged swords to the testis and male fertility. To secure better clinical evidence, future studies must faithfully implement existing and emerging good practice guidelines.

Anti-prostate cancer protection and therapy in the framework of predictive, preventive and personalised medicine — comprehensive effects of phytochemicals in primary, secondary and tertiary care

According to the GLOBOCAN 2020, prostate cancer (PCa) is the most often diagnosed male cancer in 112 countries and the leading cancer-related death in 48 countries. Moreover, PCa incidence permanently increases in adolescents and young adults. Also, the rates of metastasising PCa continuously grow up in young populations. Corresponding socio-economic burden is enormous: PCa treatment costs increase more rapidly than for any other cancer. In order to reverse current trends in exploding PCa cases and treatment costs, pragmatic decisions should be made, in favour of advanced populational screening programmes and effective anti-PCa protection at the level of the health-to-disease transition (sub-optimal health conditions) demonstrating the highest cost-efficacy of treatments. For doing this, the paradigm change from reactive treatments of the clinically manifested PCa to the predictive approach and personalised prevention is essential.

Phytochemicals are associated with potent anti-cancer activity targeting each stage of carcinogenesis including cell apoptosis and proliferation, cancer invasiveness and metastatic disease. For example, their positive effects are demonstrated for stabilising and restoring mitochondrial health quality, which if compromised is strongly associated with sub-optimal health conditions and strong predisposition to aggressive PCa sub-types. Further, phytochemicals significantly enhance response of cancer cells to anti-cancer therapies including radio- and chemotherapy. Evident plant-based mitigation of negative side-effects frequently observed for conventional anti-cancer therapies has been reported. Finally, dual anti-cancer and anti-viral effects of phytochemicals such as these of silibinin have been demonstrated as being highly relevant for improved PCa management at the level of secondary and tertiary care, for example, under pandemic conditions, since PCa-affected individuals per evidence are highly vulnerable towards COVID-19 infection.

Here, we present a comprehensive data analysis towards clinically relevant anti-cancer effects of phytochemicals to be considered for personalised anti-PCa protection in primary care as well as for an advanced disease management at the level of secondary and tertiary care in the framework of predictive, preventive and personalised medicine.

Inhibitory effect of polyphenols (phenolic acids, lignans, and stilbenes) on cancer by regulating signal transduction pathways: a review

Natural products, especially polyphenols (phenolic acids, lignans, and stilbenes) are suggested to be more potent anticancer drugs because of their no or less adverse effects, excess availability, high accuracy, and secure mode of action. In the present review, potential anticancer mechanisms of action of some polyphenols including phenolic acids, lignans, and stilbenes are discussed based on clinical, epidemiological, in vivo, and in vitro studies. The emerging evidence revealed that phenolic acids, lignans, and stilbenes induced apoptosis in the treatment of breast (MCF-7), colon (Caco-2), lung (SKLU-1), prostate (DU-145 and LNCaP), hepatocellular (hepG-2), and cervical (A-431) cancer cells, cell cycle arrest (S/G₂/M/G₁-phases) in gastric (MKN-45 and MKN-74), colorectal (HCT-116), bladder (T-24 and 5637), oral (H-400), leukemic (HL-60 and MOLT-4) and colon (Caco-2) cancer cells, and inhibit cell proliferation against the prostate (PC-3), liver (LI-90), breast (T47D and MDA-MB-231), colon (HT-29 and Caco-2), cervical (HTB-35), and MIC-1 cancer cells through caspase-3, MAPK, AMPK, Akt, NF-κB, Wnt, CD95, and SIRT1 pathways. Based on accumulated data, we suggested that polyphenols could be considered as a viable therapeutic option in the treatment of cancer cells in the near future.

Nutritional and surgical aspects in prostate disorders

Prostate disorders are commonplace in medicine, especially in older men, with prostatitis, benign prostatic hyperplasia, and prostate cancer being the most abundant pathologies. The complexity of this organ, however, turns treatment into a challenge. In this review, we aim to provide insight into the efficacy of alternative treatments, which are not normally used in conventional medicine, with a particular focus on nutrients. In order to understand why and how nutrition can be beneficial in diseases of the prostate, we give an overview of the known characteristics and features of this organ. Then, we provide a summary of the most prevalent prostate illnesses. Finally, we propose nutrition-based treatment in each of these prostate problems, based on in-depth research concerning its effects in this context, with an emphasis on surgery. Overall, we plead for an upgrade of this form of alternative treatment to a fully recognized mode of therapy for the prostate.

Impact of 18-Month Soy Protein Supplementation on Steroid Hormones and Serum Biomarkers of Angiogenesis, Apoptosis, and the Growth Hormone/IGF-1 Axis: Results of a Randomized, Placebo-Controlled Trial in Males Following Prostatectomy

Many studies have addressed the effects of dietary supplementation with soy protein on cancer risk and mortality, but there are only few randomized studies with soy in males. We used serum samples from a two-year trial of soy protein isolate supplementation in middle-aged to older males at risk of recurrence of prostate cancer after radical prostatectomy to determine soy effects on steroid hormones involved in prostate cancer (testosterone, SHBG, and estradiol) and explore the effects on biomarkers of the growth hormone/IGF-1 axis, apoptosis, and angiogenesis. Compared with a casein-based placebo, 18 mo, of consumption of 19.2 g/day of whole soy protein isolate containing 24 mg genistein-reduced circulating testosterone and SHBG, but not free testosterone, and did not affect serum concentrations of estradiol, VEGF, IGF-1, IGFBP-3, IGF-1/IGFBP-3 ratio, soluble Fas, Fas-ligand, and sFas/Fas-ligand ratio. Thus, soy protein supplementation for 18 mo, affected the androgen axis, but the effects on other cancer biomarkers remain to be more definitively determined. The study was registered at clinicaltrials.gov (NCT00765479).

Prostate cancer: Therapeutic prospect with herbal medicine

Prostate cancer (PCa) is a major cause of morbidity and mortality in men worldwide. A geographic variation on the burden of the disease suggested that the environment, genetic makeup, lifestyle, and food habits modulate one's susceptibility to the disease. Although it has been generally thought to be an older age disease, and awareness and timely execution of screening programs have managed to contain the disease in the older population over the last decades, the incidence is still increasing in the population younger than 50. Existing treatment is efficient for PCa that is localized and responsive to androgen. However, the androgen resistant and metastatic PCa are challenging to treat. Conventional radiation and chemotherapies are associated with severe side effects in addition to being exorbitantly expensive. Many isolated phytochemicals and extracts of plants used in traditional medicine are known for their safety and diverse healing properties, including many with varying levels of anti-PCa activities. Many of the phytochemicals discussed here, as shown by many laboratories, inhibit tumor cell growth and proliferation by interfering with the components in the pathways responsible for the enhanced proliferation, metabolism, angiogenesis, invasion, and metastasis in the prostate cells while upregulating the mechanisms of cell death and cell cycle arrest. Notably, many of these agents simultaneously target multiple cellular pathways. We analyzed the available literature and provided an update on this issue in this review article.

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Prostate cancer in a major cause of death in older population worldwide.

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Efficacies of current treatment options are limited in many cases.

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Phytochemicals and extracts isolated from plants show anti-prostate cancer activity with unique mechanisms.

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Certain phytochemicals alone or in combination with current chemotherapy show therapeutic promise.

Natural Product-Based Studies for the Management of Castration-Resistant Prostate Cancer: Computational to Clinical Studies

Background: With prostate cancer being the fifth-greatest cause of cancer mortality in 2020, there is a dire need to expand the available treatment options. Castration-resistant prostate cancer (CRPC) progresses despite androgen depletion therapy. The mechanisms of resistance are yet to be fully discovered. However, it is hypothesized that androgens depletion enables androgen-independent cells to proliferate and recolonize the tumor. Objectives: Natural bioactive compounds from edible plants and herbal remedies might potentially address this need. This review compiles the available cheminformatics-based studies and the translational studies regarding the use of natural products to manage CRPC. Methods: PubMed and Google Scholar searches for preclinical studies were performed, while ClinicalTrials.gov and PubMed were searched for clinical updates. Studies that were not in English and not available as full text were excluded. The period of literature covered was from 1985 to the present. Results and Conclusion: Our analysis suggested that natural compounds exert beneficial effects due to their broad-spectrum molecular disease-associated targets. In vitro and in vivo studies revealed several bioactive compounds, including rutaecarpine, berberine, curcumin, other flavonoids, pentacyclic triterpenoids, and steroid-based phytochemicals. Molecular modeling tools, including machine and deep learning, have made the analysis more comprehensive. Preclinical and clinical studies on resveratrol, soy isoflavone, lycopene, quercetin, and gossypol have further validated the translational potential of the natural products in the management of prostate cancer.

Flavonoids against non-physiologic inflammation attributed to cancer initiation, development, and progression—3PM pathways

Inflammation is an essential pillar of the immune defense. On the other hand, chronic inflammation is considered a hallmark of cancer initiation and progression. Chronic inflammation demonstrates a potential to induce complex changes at molecular, cellular, and organ levels including but not restricted to the stagnation and impairment of healing processes, uncontrolled production of aggressive ROS/RNS, triggered DNA mutations and damage, compromised efficacy of the DNA repair machinery, significantly upregulated cytokine/chemokine release and associated patho-physiologic protein synthesis, activated signaling pathways involved in carcinogenesis and tumor progression, abnormal tissue remodeling, and created pre-metastatic niches, among others. The anti-inflammatory activities of flavonoids demonstrate clinically relevant potential as preventive and therapeutic agents to improve individual outcomes in diseases linked to the low-grade systemic and chronic inflammation, including cancers. To this end, flavonoids are potent modulators of pro-inflammatory gene expression being, therefore, of great interest as agents selectively suppressing molecular targets within pro-inflammatory pathways. This paper provides in-depth analysis of anti-inflammatory properties of flavonoids, highlights corresponding mechanisms and targeted molecular pathways, and proposes potential treatment models for multi-level cancer prevention in the framework of predictive, preventive, and personalized medicine (PPPM / 3PM). To this end, individualized profiling and patient stratification are essential for implementing targeted anti-inflammatory approaches. Most prominent examples are presented for the proposed application of flavonoid-conducted anti-inflammatory treatments in overall cancer management.

The Soybean High Density 'Forrest' by 'Williams 82' SNP-Based Genetic Linkage Map Identifies QTL and Candidate Genes for Seed Isoflavone Content

Isoflavones are secondary metabolites that are abundant in soybean and other legume seeds providing health and nutrition benefits for both humans and animals. The objectives of this study were to construct a single nucleotide polymorphism (SNP)-based genetic linkage map using the ‘Forrest’ by ‘Williams 82’ (F×W82) recombinant inbred line (RIL) population (n = 306); map quantitative trait loci (QTL) for seed daidzein, genistein, glycitein, and total isoflavone contents in two environments over two years (NC-2018 and IL-2020); identify candidate genes for seed isoflavone. The FXW82 SNP-based map was composed of 2075 SNPs and covered 4029.9 cM. A total of 27 QTL that control various seed isoflavone traits have been identified and mapped on chromosomes (Chrs.) 2, 4, 5, 6, 10, 12, 15, 19, and 20 in both NC-2018 (13 QTL) and IL-2020 (14 QTL). The six QTL regions on Chrs. 2, 4, 5, 12, 15, and 19 are novel regions while the other 21 QTL have been identified by other studies using different biparental mapping populations or genome-wide association studies (GWAS). A total of 130 candidate genes involved in isoflavone biosynthetic pathways have been identified on all 20 Chrs. And among them 16 have been identified and located within or close to the QTL identified in this study. Moreover, transcripts from four genes (Glyma.10G058200, Glyma.06G143000, Glyma.06G137100, and Glyma.06G137300) were highly abundant in Forrest and Williams 82 seeds. The identified QTL and four candidate genes will be useful in breeding programs to develop soybean cultivars with high beneficial isoflavone contents.

Therapeutic Potential of Isoflavones with an Emphasis on Daidzein

Daidzein is a phytoestrogen isoflavone found in soybeans and other legumes. The chemical composition of daidzein is analogous to mammalian estrogens, and it could be useful with a dual-directional purpose by substituting/hindering with estrogen and estrogen receptor (ER) complex. Hence, daidzein puts forth shielding effects against a great number of diseases, especially those associated with the control of estrogen, such as breast cancer, diabetes, osteoporosis, and cardiovascular disease. However, daidzein also has other ER-independent biological activities, such as oxidative damage reduction acting as an antioxidant, immune regulator as an anti-inflammatory agent, and apoptosis regulation, directly linked to its potential anticancer effects. In this sense, the present review is aimed at providing a deepen analysis of daidzein pharmacodynamics and its implications in human health, from its best-known effects alleviating postmenopausal symptoms to its potential anticancer and antiaging properties.

Exploring the Biological Activity and Mechanism of Xenoestrogens and Phytoestrogens in Cancers: Emerging Methods and Concepts

Xenoestrogens and phytoestrogens are referred to as "foreign estrogens" that are produced outside of the human body and have been shown to exert estrogen-like activity. Xenoestrogens are synthetic industrial chemicals, whereas phytoestrogens are chemicals present in the plant. Considering that these environmental estrogen mimics potentially promote hormone-related cancers, an understanding of how they interact with estrogenic pathways in human cells is crucial to resolve their possible impacts in cancer. Here, we conducted an extensive literature evaluation on the origins of these chemicals, emerging research techniques, updated molecular mechanisms, and ongoing clinical studies of estrogen mimics in human cancers. In this review, we describe new applications of patient-derived xenograft (PDX) models and single-cell RNA sequencing (scRNA-seq) techniques in shaping the current knowledge. At the molecular and cellular levels, we provide comprehensive and up-to-date insights into the mechanism of xenoestrogens and phytoestrogens in modulating the hallmarks of cancer. At the systemic level, we bring the emerging concept of window of susceptibility (WOS) into focus. WOS is the critical timing during the female lifespan that includes the prenatal, pubertal, pregnancy, and menopausal transition periods, during which the mammary glands are more sensitive to environmental exposures. Lastly, we reviewed 18 clinical trials on the application of phytoestrogens in the prevention or treatment of different cancers, conducted from 2002 to the present, and provide evidence-based perspectives on the clinical applications of phytoestrogens in cancers. Further research with carefully thought-through concepts and advanced methods on environmental estrogens will help to improve understanding for the identification of environmental influences, as well as provide novel mechanisms to guide the development of prevention and therapeutic approaches for human cancers.

Randomized, Placebo-Controlled Six-Month Intervention Study of Soy Protein Isolate in Men with Biochemical Recurrence after Radical Prostatectomy: A Pilot Study

There is evidence to suggest that soy may be beneficial for prostate cancer patients, but few randomized trials have addressed this. We examined the effect of 6-8 mo soy protein supplementation on prostate specific antigen (PSA) serum levels in men who recurred (PSA > 0.1 ng/ml) within three years of prostatectomy. Sixteen men were randomized to 20 g soy protein (∼24-26/day genistein; ∼40-43/day total isoflavones) or casein placebo. PSA was measured at base line and at 1, 2, 4, and 6-8 mo. Serum genistein levels greatly increased from baseline and cholesterol decreased in the soy group. In both treatment arms PSA increased similarly and PSA doubling times were not different over the 6-8 mo study duration. Two subjects in each group had stable PSA. A literature search for clinical studies of soy, isoflavones, and PSA revealed that supplementation with soy or isoflavones did not affect PSA in virtually all clinical studies identified. Although this study is too small to draw a definitive conclusion on the effect of soy protein on PSA in men with biochemical failure, the null finding in this study is consistent with the results of virtually all reports of soy and soy isoflavones in the literature.

Natural isoflavonoids in invasive cancer therapy: From bench to bedside

Cancer is a public health problem worldwide, and one of the crucial steps within tumor progression is the invasion and metastasis of cancer cells, which are directly related to cancer-associated deaths in patients. Recognizing the molecular markers involved in invasion and metastasis is essential to find targeted therapies in cancer. Interestingly, about 50% of the discovered drugs used in chemotherapy have been obtained from natural sources such as plants, including isoflavonoids. Until now, most drugs are used in chemotherapy targeting proliferation and apoptosis-related molecules. Here, we review recent studies about the effect of isoflavonoids on molecular targets and signaling pathways related to invasion and metastasis in cancer cell cultures, in vivo assays, and clinical trials. This review also reports that glycitein, daidzein, and genistein are the isoflavonoids most studied in preclinical and clinical trials and displayed the most anticancer activity targeting invasion-related proteins such as MMP-2 and MMP-9 and also EMT-associated proteins. Therefore, the diversity of isoflavonoids is promising molecules to be used as chemotherapeutic in invasive cancer. In the future, more clinical trials are needed to validate the effectiveness of the various natural isoflavonoids in the treatment of invasive cancer.

Soy protein supplementation in men following radical prostatectomy: a 2-year randomized, placebo-controlled clinical trial

BACKGROUND

Many studies have addressed effects of dietary supplementation with soy protein, but most have been inconsistent and few have been long-term studies in men.

OBJECTIVES

This study was a secondary analysis of body weight, blood pressure, thyroid hormones, iron status, and clinical chemistry in a 2-y trial of soy protein supplementation in middle-aged to older men.

METHODS

Data were analyzed as secondary outcomes of a randomized controlled trial of dietary supplementation with 20 g/d soy protein isolate, providing 41 mg/d total isoflavones and 23 mg/d genistein, in 44- to 75-y-old men who were at risk of cancer recurrence following prostatectomy randomized to soy (n = 50) or a casein-based placebo (n  = 43). Weight, blood pressure, and blood samples were collected at baseline, every 2 mo in year 1, and every 3 mo in year 2.

RESULTS

Compared with casein, soy supplementation did not affect body weight, blood pressure, serum total cholesterol, calcium, phosphorus, and thyroid hormones. Serum ferritin concentrations doubled over 2 y in both groups (117-129%), whereas hemoglobin and hematocrit increased slightly. In an exploratory subgroup analysis of soy group data, weight increased in subjects producing equol but not in nonproducers. Blood pressure was reduced in nonequol producers but not in producers. Other endpoints were not affected by equol production status.

CONCLUSIONS

Soy protein supplementation for 2 y compared with a casein-based placebo did not affect body weight, blood pressure, serum total cholesterol, iron status parameters, calcium, phosphorus, and thyroid hormones. Exploratory analysis suggests that equol production status of subjects on soy may modify effects of soy on body weight and possibly blood pressure. This trial was registered at clinicaltrials.gov as NCT00765479.

Neither soy nor isoflavone intake affects male reproductive hormones: An expanded and updated meta-analysis of clinical studies

Concerns that the phytoestrogens (isoflavones) in soy may feminize men continue to be raised. Several studies and case-reports describing feminizing effects including lowering testosterone levels and raising estrogen levels in men have been published. For this reason, the clinical data were meta-analyzed to determine whether soy or isoflavone intake affects total testosterone (TT), free testosterone (FT), estradiol (E₂), estrone (E₁), and sex hormone binding globulin (SHBG). PubMed and CAB Abstracts databases were searched between 2010 and April 2020, with use of controlled vocabulary specific to the databases. Peer-reviewed studies published in English were selected if (1) adult men consumed soyfoods, soy protein, or isoflavone extracts (from soy or red clover) and [2] circulating TT, FT, SHBG, E2 or E1 was assessed. Data were extracted by two independent reviewers. With one exception, studies included in a 2010 meta-analysis were included in the current analysis. A total of 41 studies were included in the analyses. TT and FT levels were measured in 1753 and 752 men, respectively; E₂ and E₁ levels were measured in 1000 and 239 men, respectively and SHBG was measured in 967 men. Regardless of the statistical model, no significant effects of soy protein or isoflavone intake on any of the outcomes measured were found. Sub-analysis of the data according to isoflavone dose and study duration also showed no effect. This updated and expanded meta-analysis indicates that regardless of dose and study duration, neither soy protein nor isoflavone exposure affects TT, FT, E₂ or E₁ levels in men.

Dietary Factors and Supplements Influencing Prostate Specific-Antigen (PSA) Concentrations in Men with Prostate Cancer and Increased Cancer Risk: An Evidence Analysis Review Based on Randomized Controlled Trials

The quest for dietary patterns and supplements efficient in down-regulating prostate-specific antigen (PSA) concentrations among men with prostate cancer (PCa) or increased PCa risk has been long. Several antioxidants, including lycopene, selenium, curcumin, coenzyme Q10, phytoestrogens (including isoflavones and flavonoids), green tea catechins, cernitin, vitamins (C, E, D) and multivitamins, medicinal mushrooms (Ganoderma lucidum), fruit extracts (saw palmetto, cranberries, pomegranate), walnuts and fatty acids, as well as combined supplementations of all, have been examined in randomized controlled trials (RCTs) in humans, on the primary, secondary, and tertiary PCa prevention level. Despite the plethora of trials and the variety of examined interventions, the evidence supporting the efficacy of most dietary factors appears inadequate to recommend their use.

RENISUS Plants and Their Potential Antitumor Effects in Clinical Trials and Registered Patents

Cancer is a significant cause of morbidity and mortality. Scientific advances, coupled with potential flaws in current treatments, are driving research into the discovery of new bioactive molecules. This systematic review focused on scientific studies with clinical trials and patents registered on the National Relation of Medicinal Plants of Interest to the Unified Health System (RENISUS) plants (or derivative compounds) with antitumor potential. Studies with 19 different forms of cancer were found, the prostate being the organ with the highest research incidence and the species Glycine max, Curcuma longa, and Zingiber officinale, beside the phytochemicals curcumin and soy isoflavone were the most tested in clinical trials/patents.

Effects of Dietary Phytoestrogens on Hormones throughout a Human Lifespan: A Review

Dietary phytoestrogens are bioactive compounds with estrogenic activity. With the growing popularity of plant-based diets, the intake of phytoestrogen-rich legumes (especially soy) and legume-derived foods has increased. Evidence from preclinical studies suggests these compounds may have an effect on hormones and health, although the results of human trials are unclear. The effects of dietary phytoestrogens depend on the exposure (phytoestrogen type, matrix, concentration, and bioavailability), ethnicity, hormone levels (related to age, sex, and physiological condition), and health status of the consumer. In this review, we have summarized the results of human studies on dietary phytoestrogens with the aim of assessing the possible hormone-dependent outcomes and health effects of their consumption throughout a lifespan, focusing on pregnancy, childhood, adulthood, and the premenopausal and postmenopausal stages. In pregnant women, an improvement of insulin metabolism has been reported in only one study. Sex hormone alterations have been found in the late stages of childhood, and goitrogenic effects in children with hypothyroidism. In premenopausal and postmenopausal women, the reported impacts on hormones are inconsistent, although beneficial goitrogenic effects and improved glycemic control and cardiovascular risk markers have been described in postmenopausal individuals. In adult men, different authors report goitrogenic effects and a reduction of insulin in non-alcoholic fatty liver patients. Further carefully designed studies are warranted to better elucidate the impact of phytoestrogen consumption on the endocrine system at different life stages.

Can Isoflavones Influence Prostate Specific Antigen Serum Levels in Localized Prostate Cancer? A Systematic Review

Low risk prostate cancer does not always necessitate aggressive or invasive intervention and is best monitored through active surveillance, but in daily practice a majority of men seek a more proactive approach. Therefore, tertiary chemoprevention is an attractive option for men seeking a way to slow disease progression. Several natural anti-carcinogens have been identified in soy beans, especially isoflavones. Case series have been published, demonstrating a positive influence of isoflavones on PSA serum levels in prostate cancer. Consequently, we decided to perform a systematic review about the effect of isoflavones compared to placebo on PSA levels in localized prostate cancer following the recommendations provided in the Cochrane Handbook of systematic Reviews. On the whole, the primary aim of this review is to summarize the evidence for the use of isoflavones in localized prostate cancer in terms of PSA response. As a result, in all randomized controlled trials identified for this review, isoflavones seem to have no influence on PSA levels in localized prostate cancer. The influence of isoflavones on overall survival in localized prostate cancer remains unclear. Furthermore, isoflavones are interesting substances for further research, for example in lipid metabolism and cholesterol.

A phase II randomized clinical trial using aglycone isoflavones to treat patients with localized prostate cancer in the pre-surgical period prior to radical prostatectomy

Prostate cancer (PCa) is the most common cancer in American men. Additionally, African American Men (AAM) are 60% more likely to be diagnosed with PCa and 2.4 times more likely to die from this disease compared to Caucasian men (CM). To date, there are few strategies effective for chemoprevention for men with localized PCa. There is thus a need to continue to evaluate agents and strategies for chemoprevention of prostate cancer. Epidemiological, laboratory and early phase clinical trials have shown that the isoflavones modulates several biomarkers implicated in prostate carcinogenesis. The goal of this phase II randomized clinical trial was to explore the comparative effectiveness and safety of 40 mgs of aglycone isoflavones in AAM and CM with localized PCa in the pre-surgical period prior to radical prostatectomy. Thirty six participants (25 CM, 6AAM) were randomized to the isoflavone arm and 34 (25 CM, 7AAM) to the placebo arm, with 62 completing the intervention. Results indicated that isoflavones at a dose of 20 mgs BID for 3-6 weeks was well tolerated but did not reduce tissue markers of proliferation. A significant reduction in serum PSA was observed with isoflavone supplementation in CM compared to the placebo arm, but not observed in AAM. We observed no changes in serum steroid hormones with isoflavone supplementation. In AAM, a reduction in serum IGF-1 concentrations and IGF1: IGFBP-3 ratios were observed with isoflavone supplementation. Well-powered studies for longer duration of intervention may inform future trials with isoflavones, for chemoprevention of PCa.

Cancer prevention and treatment using combination therapy with natural compounds

Introduction: Naturally occurring compounds play an essential role in the prevention and treatment of various cancers. There are more than 100 plant and animal based natural compounds currently in clinical use.Areas covered: 1) The importance of natural products combinations in the prevention and treatment of cancer, 2) the need to maximize efficacy while minimizing side effects when using natural product combinations, and 3) specifics related to plant and animal derived natural products, as well as agents derived from natural products. Therapies using natural compounds that have been investigated, their rationale, mechanism of action and findings are reviewed. When the data warrant it, combined interventions that appear to increase efficacy (compared with monotherapy) while minimizing toxicity have been highlighted. Pubmed was used to search for relevant publications.Expert opinion: Combination therapy with natural compounds has the potential to be more effective than single agent therapy. Similar to pharmacologic agents, the goal is to maximize efficacy while mimimizing potential side effects. There is an increasing research focus on the development of agents derived from natural products, with notable successes already achieved from the effort.

Influence of Diet and Nutrition on Prostate Cancer

The incidence of prostate cancer (PCa) displays widespread regional differences, probably owing to differences in dietary habits. Nutrients, including fat, protein, carbohydrates, vitamins (vitamin A, D, and E), and polyphenols, potentially affect PCa pathogenesis and progression, as previously reported using animal models; however, clinical studies have reported controversial results for almost all nutrients. The effects of these nutrients may be manifested through various mechanisms including inflammation, antioxidant effects, and the action of sex hormones. Dietary patterns including the Western and Prudent patterns also influence the risk of PCa. Recent studies reported that the gut microbiota contribute to tumorigenesis in some organs. Diet composition and lifestyle have a direct and profound effect on the gut bacteria. Human studies reported an increase in the abundance of specific gut bacteria in PCa patients. Although there are few studies concerning their relationship, diet and nutrition could influence PCa, and this could be mediated by gut microbiota. An intervention of dietary patterns could contribute to the prevention of PCa. An intervention targeting dietary patterns may thus help prevent PCa.

Diet and lifestyle considerations for patients with prostate cancer

PURPOSE

To review the literature and provide recommendations on diet and lifestyle considerations in patients with prostate cancer using evidence from randomized controlled trials (RCTs) with additional considerations based on observational evidence.

MATERIALS AND METHODS

We initiated our search on ClinicalTrials.gov combining the term "prostate cancer" with a variety of diet and lifestyle factors. We then supplemented our summary of publications from registered trials by including other publications available on Pubmed.

RESULTS

There is a well-established benefit of exercise for improving functional outcomes and pelvic floor muscle training for improving treatment-related adverse effects. Multimodality interventions that integrate several factors (e.g., low-saturated fat, plant-based, whole-food diets with exercise, and stress reduction) appear to have the most clinically significant benefit for patients with prostate cancer. Ongoing multimodality interventions are including the efficacy of implementation strategies as observed outcomes. Limited RCT evidence suggests a clinically significant benefit for guided imagery/progressive muscle relaxation, Pilates, and lycopene-rich diets and a modest benefit for green tea, qigong, massage, and avoidance of nonprescribed vitamin and mineral supplements. Observational and single arm trial evidence indicates a need for further exploration of acupuncture, coffee, cruciferous vegetables, fish, Larrea tridentata, mushrooms, and vegetable-derived fats and avoidance of eggs, dairy, poultry with skin, processed red meat, and saturated fat. Published trials suggest no benefit from hypnosis, milk thistle, pomegranate, soy, or omega-3 fatty acid supplementation.

CONCLUSIONS

Our search demonstrated that most diet and lifestyle factors identified from observational studies have limited data from RCTs. Few items have shown early evidence of benefit. The best recommendation for patients with prostate cancer is to form a habit of wellness through healthy eating, aerobic and resistance exercise, and psychological well-being. Future trial development should consider how interventions can be implemented into real world practice.

Dietary Flavonoids for Immunoregulation and Cancer: Food Design for Targeting Disease

Flavonoids, one of the most abundant phytochemicals in a diet rich in fruits and vegetables, have been recognized as possessing anti-proliferative, antioxidant, anti-inflammatory, and estrogenic activities. Numerous cellular and animal-based studies show that flavonoids can function as antioxidants by preventing DNA damage and scavenging reactive oxygen radicals, inhibiting formation of DNA adducts, enhancing DNA repair, interfering with chemical damage by induction of Phase II enzymes, and modifying signaling pathways. Recent evidence also shows their ability to regulate the immune system. However, findings from clinical trials have been mixed with no clear consensus on dose, frequency, or type of flavonoids best suited to elicit many of the beneficial effects. Delivery of these bioactive compounds to their biological targets through "targeted designed" food processing strategies is critical to reach effective concentration in vivo. Thus, the identification of novel approaches that optimize flavonoid bioavailability is essential for their successful clinical application. In this review, we discuss the relevance of increasing flavonoid bioavailability, by agricultural engineering and "targeted food design" in the context of the immune system and cancer.

Molecular Mechanisms and Bioavailability of Polyphenols in Prostate Cancer

Prostate cancer is the one of the most frequently diagnosed cancers among men over the age of 50. Several lines of evidence support the observation that polyphenols have preventive and therapeutic effects in prostate cancer. Moreover, prostate cancer is ideal for chemoprevention due to its long latency. We propose here an equilibrated lifestyle with a diet rich in polyphenols as prophylactic attempts to slow down the progression of localized prostate cancer or prevent the occurrence of the disease. In this review, we will first summarize the molecular mechanisms of polyphenols in prostate cancer with a focus on the antioxidant and pro-oxidant effects, androgen receptors (AR), key molecules involved in AR signaling and their transactivation pathways, cell cycle, apoptosis, angiogenesis, metastasis, genetic aspects, and epigenetic mechanisms. The relevance of the molecular mechanisms is discussed in light of current bioavailability data regarding the activity of polyphenols in prostate cancer. We also highlight strategies for improving the bioavailability of polyphenols. We hope that this review will lead to further research regarding the bioavailability and the role of polyphenols in prostate cancer prevention and treatment.

Androgen receptor and soy isoflavones in prostate cancer

Androgens and androgen receptor (AR) play a critical role not only in normal prostate development, but also in prostate cancer. For that reason, androgen deprivation therapy (ADT) is the primary treatment for prostate cancer. However, the majority of patients develop castration-resistant prostate cancer, which eventually leads to mortality. Novel therapeutic approaches, including dietary changes, have been explored. Soy isoflavones have become a focus of interest because of their positive health benefits on numerous diseases, particularly hormone-related cancers, including prostate and breast cancers. An important strategy for the prevention and/or treatment of prostate cancer might thus be the action of soy isoflavones on the AR signaling pathway. The current review article provides a detailed overview of the anticancer potential of soy isoflavones (genistein, daidzein and glycitein), as mediated by their effect on AR.

Nutraceuticals in prostate cancer therapeutic strategies and their neo-adjuvant use in diverse populations

Prostate cancer (PCa) is the most frequently diagnosed malignancy and second leading cause of cancer mortality in American males. Notably, men of African descent in the United States and Caribbean have the highest PCa mortality rates compared to men with European ancestry. Although current therapeutics are quite potent and effective, disease resistance, progression to metastasis, therapy-associated toxicities and efficacy-related issues in diverse populations develop over time. Thus, non-toxic and efficacious therapeutic strategies are needed to address these major obstacles for the clinical treatment and management of PCa. In this regard, preclinical and population-based efficacy studies have shown the potential of natural non-toxic nutraceuticals as potent anti-PCa agents. Accordingly, the implementation of nutraceutical intervention and genetic testing in diverse populations might aid in the development and design of precision medicine strategies to reduce the burden of chemotherapy-associated toxicities, suppress disease resistance, and treat both localized and advanced PCa. Consequently, additional large-scale and inclusive clinical studies are required to fully assess efficacy and therapeutic limitations of these agents in PCa. This review discusses the most current clinical research on selected nutraceutical agents and their efficacy in the context of clinico-pathological outcomes and disease susceptibility in diverse PCa clinical and epidemiological studies.

Prostate cancer chemoprevention by natural agents: Clinical evidence and potential implications

Prostate cancer (PCa) is the most common non-skin cancer and the second leading cause of cancer-related deaths in American men. Due to its long latency period, PCa is considered as an ideal cancer type for chemopreventive interventions. Chemopreventive agents include various natural or synthetic agents that prevent or delay cancer development, progression and/or recurrence. Pre-clinical studies suggest that many natural products and dietary agents have chemopreventive properties. However, a limited number of these agents have been tested in clinical trials, with varying success. In this review, we have discussed the available clinical studies regarding the efficacy of natural chemopreventive agents against PCa, including tea polyphenols, selenium, soy proteins, vitamins and resveratrol. We have also provided a discussion on the clinical challenges and opportunities for the potential use of chemopreventive agents against PCa. Based on available literature, it appears that the variable outcomes of the chemopreventive clinical studies necessitate a need for additional studies with more rigorous designs and methodical interpretations in order to measure the potential of the natural agents against PCa.

Interventions to reduce acute and late adverse gastrointestinal effects of pelvic radiotherapy for primary pelvic cancers

BACKGROUND

An increasing number of people survive cancer but a significant proportion have gastrointestinal side effects as a result of radiotherapy (RT), which impairs their quality of life (QoL).

OBJECTIVES

To determine which prophylactic interventions reduce the incidence, severity or both of adverse gastrointestinal effects among adults receiving radiotherapy to treat primary pelvic cancers.

SEARCH METHODS

We conducted searches of CENTRAL, MEDLINE, and Embase in September 2016 and updated them on 2 November 2017. We also searched clinical trial registries.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of interventions to prevent adverse gastrointestinal effects of pelvic radiotherapy among adults receiving radiotherapy to treat primary pelvic cancers, including radiotherapy techniques, other aspects of radiotherapy delivery, pharmacological interventions and non-pharmacological interventions. Studies needed a sample size of 20 or more participants and needed to evaluate gastrointestinal toxicity outcomes. We excluded studies that evaluated dosimetric parameters only. We also excluded trials of interventions to treat acute gastrointestinal symptoms, trials of altered fractionation and dose escalation schedules, and trials of pre- versus postoperative radiotherapy regimens, to restrict the vast scope of the review.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology. We used the random-effects statistical model for all meta-analyses, and the GRADE system to rate the certainty of the evidence.

MAIN RESULTS

We included 92 RCTs involving more than 10,000 men and women undergoing pelvic radiotherapy. Trials involved 44 different interventions, including radiotherapy techniques (11 trials, 4 interventions/comparisons), other aspects of radiotherapy delivery (14 trials, 10 interventions), pharmacological interventions (38 trials, 16 interventions), and non-pharmacological interventions (29 trials, 13 interventions). Most studies (79/92) had design limitations. Thirteen studies had a low risk of bias, 50 studies had an unclear risk of bias and 29 studies had a high risk of bias. Main findings include the following:Radiotherapy techniques: Intensity-modulated radiotherapy (IMRT) versus 3D conformal RT (3DCRT) may reduce acute (risk ratio (RR) 0.48, 95% confidence interval (CI) 0.26 to 0.88; participants = 444; studies = 4; I2 = 77%; low-certainty evidence) and late gastrointestinal (GI) toxicity grade 2+ (RR 0.37, 95% CI 0.21 to 0.65; participants = 332; studies = 2; I2 = 0%; low-certainty evidence). Conformal RT (3DCRT or IMRT) versus conventional RT reduces acute GI toxicity grade 2+ (RR 0.57, 95% CI 0.40 to 0.82; participants = 307; studies = 2; I2 = 0%; high-certainty evidence) and probably leads to less late GI toxicity grade 2+ (RR 0.49, 95% CI 0.22 to 1.09; participants = 517; studies = 3; I2 = 44%; moderate-certainty evidence). When brachytherapy (BT) is used instead of external beam radiotherapy (EBRT) in early endometrial cancer, evidence indicates that it reduces acute GI toxicity (grade 2+) (RR 0.02, 95% CI 0.00 to 0.18; participants = 423; studies = 1; high-certainty evidence).Other aspects of radiotherapy delivery: There is probably little or no difference in acute GI toxicity grade 2+ with reduced radiation dose volume (RR 1.21, 95% CI 0.81 to 1.81; participants = 211; studies = 1; moderate-certainty evidence) and maybe no difference in late GI toxicity grade 2+ (RR 1.02, 95% CI 0.15 to 6.97; participants = 107; studies = 1; low-certainty evidence). Evening delivery of RT may reduce acute GI toxicity (diarrhoea) grade 2+ during RT compared with morning delivery of RT (RR 0.51, 95% CI 0.34 to 0.76; participants = 294; studies = 2; I2 = 0%; low-certainty evidence). There may be no difference in acute (RR 2.22, 95% CI 0.62 to 7.93, participants = 110; studies = 1) and late GI toxicity grade 2+ (RR 0.44, 95% CI 0.12 to 1.65; participants = 81; studies = 1) between a bladder volume preparation of 1080 mls and that of 540 mls (low-certainty evidence). Low-certainty evidence on balloon and hydrogel spacers suggests that these interventions for prostate cancer RT may make little or no difference to GI outcomes.Pharmacological interventions: Evidence for any beneficial effects of aminosalicylates, sucralfate, amifostine, corticosteroid enemas, bile acid sequestrants, famotidine and selenium is of a low or very low certainty. However, evidence on certain aminosalicylates (mesalazine, olsalazine), misoprostol suppositories, oral magnesium oxide and octreotide injections suggests that these agents may worsen GI symptoms, such as diarrhoea or rectal bleeding.Non-pharmacological interventions: Low-certainty evidence suggests that protein supplements (RR 0.23, 95% CI 0.07 to 0.74; participants = 74; studies = 1), dietary counselling (RR 0.04, 95% CI 0.00 to 0.60; participants = 74; studies = 1) and probiotics (RR 0.43, 95% CI 0.22 to 0.82; participants = 923; studies = 5; I2 = 91%) may reduce acute RT-related diarrhoea (grade 2+). Dietary counselling may also reduce diarrhoeal symptoms in the long term (at five years, RR 0.05, 95% CI 0.00 to 0.78; participants = 61; studies = 1). Low-certainty evidence from one study (108 participants) suggests that a high-fibre diet may have a beneficial effect on GI symptoms (mean difference (MD) 6.10, 95% CI 1.71 to 10.49) and quality of life (MD 20.50, 95% CI 9.97 to 31.03) at one year. High-certainty evidence indicates that glutamine supplements do not prevent RT-induced diarrhoea. Evidence on various other non-pharmacological interventions, such as green tea tablets, is lacking.Quality of life was rarely and inconsistently reported across included studies, and the available data were seldom adequate for meta-analysis.

AUTHORS' CONCLUSIONS

Conformal radiotherapy techniques are an improvement on older radiotherapy techniques. IMRT may be better than 3DCRT in terms of GI toxicity, but the evidence to support this is uncertain. There is no high-quality evidence to support the use of any other prophylactic intervention evaluated. However, evidence on some potential interventions shows that they probably have no role to play in reducing RT-related GI toxicity. More RCTs are needed for interventions with limited evidence suggesting potential benefits.

Soy, Soy Foods and Their Role in Vegetarian Diets

Soy is a basic food ingredient of traditional Asian cuisine used for thousands of years. In Western countries, soybeans have been introduced about a hundred years ago and recently they are mainly used for surrogate foods production. Soy and soy foods are common nutritional solutions for vegetarians, due to their high protein content and versatility in the production of meat analogues and milk substitutes. However, there are some doubts about the potential effects on health, such as the effectiveness on cardiovascular risk reduction or, conversely, on the possible disruption of thyroid function and sexual hormones. The soy components that have stimulated the most research interest are isoflavones, which are polyphenols with estrogenic properties highly contained in soybeans. In this review, we discuss the characteristics of soy and soy foods, focusing on their nutrient content, including phytoestrogens and other bioactive substances that are noteworthy for vegetarians, the largest soy consumers in the Western countries. The safety of use will also be discussed, given the growing trend in adoption of vegetarian styles and the new soy-based foods availability.

Soy Consumption and the Risk of Prostate Cancer: An Updated Systematic Review and Meta-Analysis

Prostate cancer (PCa) is the second most commonly diagnosed cancer in men, accounting for 15% of all cancers in men worldwide. Asian populations consume soy foods as part of a regular diet, which may contribute to the lower PCa incidence observed in these countries. This meta-analysis provides a comprehensive updated analysis that builds on previously published meta-analyses, demonstrating that soy foods and their isoflavones (genistein and daidzein) are associated with a lower risk of prostate carcinogenesis. Thirty articles were included for analysis of the potential impacts of soy food intake, isoflavone intake, and circulating isoflavone levels, on both primary and advanced PCa. Total soy food (p < 0.001), genistein (p = 0.008), daidzein (p = 0.018), and unfermented soy food (p < 0.001) intakes were significantly associated with a reduced risk of PCa. Fermented soy food intake, total isoflavone intake, and circulating isoflavones were not associated with PCa risk. Neither soy food intake nor circulating isoflavones were associated with advanced PCa risk, although very few studies currently exist to examine potential associations. Combined, this evidence from observational studies shows a statistically significant association between soy consumption and decreased PCa risk. Further studies are required to support soy consumption as a prophylactic dietary approach to reduce PCa carcinogenesis.

An update of research evidence on nutrition and prostate cancer

BACKGROUND

Prostate cancer (PCa) remains a leading cause of mortality in US and other countries. Preclinical and clinical studies have examined the role of nutrition and dietary intake on the incidence and progression of PCa with mixed results.

OBJECTIVE

The objective of this chapter is to provide an update of recent published literature and highlight progress in the field.

MAIN FINDINGS

Low carbohydrate intake, soy protein, ω3 fat, green teas, tomatoes and tomato products and the herbal mixture-zyflamend showed promise in reducing PCa risk or progression. On the contrary, a higher animal fat intake and a higher β-carotene status may increase risk. A "U" shape relationship may exist between folate, vitamin C, vitamin D and calcium with PCa risk. Conclusion Despite the inconclusive findings, the potential for a role of dietary intake for the prevention and treatment of PCa remains promising. Maintaining a healthy body weight and following a healthy dietary pattern including antioxidant rich fruits and vegetables, reduced animal fat and refined carbohydrates, should be encouraged.

CONCLUSION

Despite the inconclusive findings, the potential for a role of dietary intake for the prevention and treatment of PCa remains promising. Maintaining a healthy body weight and following a healthy dietary pattern including antioxidant rich fruits and vegetables, reduced animal fat and refined carbohydrates, should be encouraged.

Antioxidant polyphenols in cancer treatment: Friend, foe or foil?

Cancer prevention can be probably obtained with easier, faster and less financial strains by pursuing educational programs aimed to induce changes in lifestyle, starting from dietary habits. In the past decades, observational and case-control studies tried to establish a functional relationship between cancer mortality and morbidity and diet. The field becomes even more intricate when scientists investigated which dietary components are responsible for the putative, protective effects of fruits and vegetables against cancer. A relevant part of the literature focused on the positive role of "antioxidant" compounds in foods, including polyphenols. The present review critically evaluate clinical and pre-clinical studies based on polyphenol administration, which contributed to support the concept, deeply rooted in the general population, that antioxidant polyphenols can fight cancer. The controversial and contradictory issues related to the pros and cons on the use of polyphenols against cancer reflect the confounding assumption that cancer treatment and cancer prevention may overlap. We conclude that a clear cut must be done between these two concepts and that the experimental approaches to investigate one or the other should be significantly different, starting from adequate and specifically selected cellular models.

An updated review of dietary isoflavones: Nutrition, processing, bioavailability and impacts on human health

Isoflavones (genistein, daidzein, and glycitein) are bioactive compounds with mildly estrogenic properties and often referred to as phytoestrogen. These are present in significant quantities (up to 4-5 mg·g^-1 on dry basis) in legumes mainly soybeans, green beans, mung beans. In grains (raw materials) they are present mostly as glycosides, which are poorly absorbed on consumption. Thus, soybeans are processed into various food products for digestibility, taste and bioavailability of nutrients and bioactives. Main processing steps include steaming, cooking, roasting, microbial fermentation that destroy protease inhibitors and also cleaves the glycoside bond to yield absorbable aglycone in the processed soy products, such as miso, natto, soy milk, tofu; and increase shelf lives. Processed soy food products have been an integral part of regular diets in many Asia-Pacific countries for centuries, e.g. China, Japan and Korea. However, in the last two decades, there have been concerted efforts to introduce soy products in western diets for their health benefits with some success. Isoflavones were hailed as magical natural component that attribute to prevent some major prevailing health concerns. Consumption of soy products have been linked to reduction in incidence or severity of chronic diseases such as cardiovascular, breast and prostate cancers, menopausal symptoms, bone loss, etc. Overall, consuming moderate amounts of traditionally prepared and minimally processed soy foods may offer modest health benefits while minimizing potential for any adverse health effects.

Isoflavones and Prostate Cancer: A Review of Some Critical Issues

Objective:

The purpose of this review is to discuss some critical issues of isoflavones protective against the development of prostate cancer (PCa).

Data Sources:

Data cited in this review were obtained primarily from PubMed and Embase from 1975 to 2015.

Study Selection:

Articles were selected with the search terms “isoflavone”, “Phytoestrogen”, “soy”, “genistin”, and “PCa”.

Results:

Isoflavones do not play an important role on prostate-specific antigen levels reduction in PCa patients or healthy men. The effect of isoflavones on sex hormone levels and PCa risk may be determined by equol converting bacteria in the intestine, specific polymorphic variation and concentrations of isoflavones. The intake of various types of phytoestrogens with lower concentrations in the daily diet may produce synergistic effects against PCa. Moreover, prostate tissue may concentrate isoflavones to potentially anti-carcinogenic levels. In addition, it is noteworthy that isoflavones may act as an agonist in PCa.

Conclusions:

Isoflavones play a protective role against the development of PCa. However, careful consideration should be given when isoflavones are used in the prevention and treatment of PCa.

Mechanisms and therapeutic prospects of polyphenols as modulators of the aryl hydrocarbon receptor

Polyphenolic AhR modulators displayed concentration-, XRE-, gene-, species- and cell-specific agonistic/antagonistic activity.

Food-based natural products for cancer management: Is the whole greater than the sum of the parts?

The rise in cancer incidence and mortality in developing countries together with the human and financial cost of current cancer therapy mandates a closer look at alternative ways to overcome this burgeoning global healthcare problem. Epidemiological evidence for the association between cancer and diet and the long latency of most cancer progression have led to active exploration of whole and isolated natural chemicals from different naturally occurring substances in various preclinical and clinical settings. In general the lack of systemic toxicities of most 'whole' and 'isolated' natural compounds, their potential to reduce toxic doses and potential to delay the development of drug-resistance makes them promising candidates for cancer management. This review article examines the suggested molecular mechanisms affected by these substances focusing to a large extent on prostate cancer and deliberates on the disparate results obtained from cell culture, preclinical and clinical studies in an effort to highlight the use of whole extracts and isolated constituents for intervention. As such these studies underscore the importance of factors such as treatment duration, bioavailability, route of administration, selection criteria, standardized formulation and clinical end points in clinical trial design with both entities. Overall lack of parallel comparison studies between the whole natural products and their isolated compounds limits decisive conclusions regarding the superior utility of one over the other. We suggest the critical need for rigorous comparative research to identify which one of the two or both entities from nature would be best qualified to take on the mantle of cancer management.

Natural Polyphenols for Prevention and Treatment of Cancer

There is much epidemiological evidence that a diet rich in fruits and vegetables could lower the risk of certain cancers. The effect has been attributed, in part, to natural polyphenols. Besides, numerous studies have demonstrated that natural polyphenols could be used for the prevention and treatment of cancer. Potential mechanisms included antioxidant, anti-inflammation as well as the modulation of multiple molecular events involved in carcinogenesis. The current review summarized the anticancer efficacy of major polyphenol classes (flavonoids, phenolic acids, lignans and stilbenes) and discussed the potential mechanisms of action, which were based on epidemiological, in vitro, in vivo and clinical studies within the past five years.

Phytomedicine in the Treatment of Cancer: A Health Technology Assessment

INTRODUCTION

Cancer is reported to cause about 0.4 million deaths annually. The cost of diagnosis and treatment of cancer in India is enormous.

AIM

This Health Technology Assessment (HTA) aims to understand the role, effect on mortality and adverse event occurrence, and cost effectiveness of phytomedicine in cancer treatment.

MATERIALS AND METHODS

Health technology assessment by systematic review of published literature. An electronic literature search was performed in Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Medline, PubMed, Science Direct, SCOPUS, EMBASE, LANCET, and Google Scholar databases for randomized controlled trial, observational analytical studies, case control and cohort studies pertaining to phytomedicine and herbal medicine in cancer treatment published from 1987 till 2(nd) Novemeber 2014. Overall outcome measures collected included changes in mortality and adverse event profile. Cochrane Review Manager's Risk of Bias Table was used to assess the risk of bias.

RESULTS

Out of 76 studies which were screened, 14 studies involving a total of 1965 participants (817 received various forms of phytomedicine or herbal medicine in addition to conventional therapy, and 1148 received conventional therapy only) suffering from various cancers (including cancers of the breast, prostate, nasopharynx, pancreas, stomach, ovary, non-small cell lung cancer and osteosarcoma), were included in this review. In comparison with conventional therapy, phytomedicine resulted in a significant reduction in mortality: Risk Ratio (RR) 0.67 (95% Confidence Interval (CI) 0.51 to 0.90). The combination of phytomedicine with conventional therapy resulted in a significant reduction in adverse drug reactions: RR 0.62 (95% CI 0.54 to 0.71). Addition of phytomedicine to chemotherapy resulted in an increase in the annual cost of treatment by INR 1.241 Billion (US$ 19.64 Million) and prevented 25,217 deaths: the cost-effectiveness of phytomedicine is INR 49,237/death averted (US$ 779/death averted).

CONCLUSION

When taken with conventional cancer treatment, phytomedicine shows clinical and cost effectiveness. Domestic manufacturing and practice of phytomedicine should be encouraged.

The Role of Soy Phytoestrogens on Genetic and Epigenetic Mechanisms of Prostate Cancer

Soy phytoestrogens are dietary components with considerable effects on reducing the incidence of prostate cancer. Epidemiological studies demonstrated that occurrence of prostate cancer is relatively low in Asia and Southern Europe, a status associated with consuming of soy isoflavones, such as genistein, daidzein, and glycitein. Soy phytoestrogens exert their activity on molecular mechanisms, including cell-cycle control, induction of apoptosis, inhibition of angiogenesis, and metastasis. In addition, they have antioxidant activity and show regulatory effect on the expression of genes involved in DNA damage and repair. Furthermore, the epigenetic regulation of gene expression can be modified by soy phytoestrogens. They show regulatory effects on gene activity by altering DNA methylation and/or histone modification patterns. In this chapter, we discuss the role of soy phytoestrogens on the genetic and epigenetic mechanisms of prostate cancer. We attempt to provide further insight in order to understand the underlying mechanisms of protective effects of soy phytoestrogens in preventing prostate cancer.

Effect of Sulforaphane in Men with Biochemical Recurrence after Radical Prostatectomy

Increases in serum levels of prostate-specific antigen (PSA) occur commonly in prostate cancer after radical prostatectomy and are designated "biochemical recurrence." Because the phytochemical sulforaphane has been studied extensively as an anticancer agent, we performed a double-blinded, randomized, placebo-controlled multicenter trial with sulforaphane in 78 patients (mean age, 69 ± 6 years) with increasing PSA levels after radical prostatectomy. Treatment comprised daily oral administration of 60 mg of a stabilized free sulforaphane for 6 months (M0-M6) followed by 2 months without treatment (M6-M8). The study was designed to detect a 0.012 log (ng/mL)/month decrease in the log PSA slope in the sulforaphane group from M0 to M6. The primary endpoint was not reached. For secondary endpoints, median log PSA slopes were consistently lower in sulforaphane-treated men. Mean changes in PSA levels between M6 and M0 were significantly lower in the sulforaphane group (+0.099 ± 0.341 ng/mL) than in placebo (+0.620 ± 1.417 ng/mL; P = 0.0433). PSA doubling time was 86% longer in the sulforaphane than in the placebo group (28.9 and 15.5 months, respectively). PSA increases >20% at M6 were significantly greater in the placebo group (71.8%) than in the sulforaphane group (44.4%); P = 0.0163. Compliance and tolerance were very good. Sulforaphane effects were prominent after 3 months of intervention (M3-M6). After treatment, PSA slopes from M6 to M8 remained the same in the 2 arms. Daily administration of free sulforaphane shows promise in managing biochemical recurrences in prostate cancer after radical prostatectomy.