Effects of a Phytoestrogen Intervention and Estrogen Receptor β Genotype on Prostate Cancer Proliferation and PSA Concentrations-A Randomized Controlled Trial

A phytoestrogen-rich diet has been suggested to reduce tumor proliferation among men with prostate cancer, and the effect may differ between men with different polymorphisms of the estrogen receptor-beta gene (ERβ). Patients with low- or intermediate-risk prostate cancer scheduled for radical prostatectomy were randomized to an intervention group (n = 71) provided with soybeans and flaxseeds (∼200 mg phytoestrogens/day) to eat until surgery (approximately 6 wk) or to a control group (n = 69). Tumor proliferation was assessed using Ki-67 indexes, prostate-specific antigen (PSA) concentrations were analyzed in blood, and ERβ polymorphism was genotyped in all subjects. The intervention group had a 13% unit lower risk [95% confidence interval (CI): -28%, 1.8%] of a higher Ki-67 index compared to controls, but the effect was most pronounced among TT carriers of ERβ [risk difference (RD) -19%, 95% CI: -45%, 6.8%]. Subjects with genotype TC/CC had a lower risk (RD -29%, 95% CI: -46%, -1.2%) and TT genotype a higher risk (RD 25%, 95% CI: 8.7%, 42%) of increased PSA concentration, comparing the intervention group to controls. In conclusion, a phytoestrogen-rich diet may cause lower tumor proliferation and concentration of PSA in men with prostate cancer with a specific genetic upset of ERβ.

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.

Cellular Redox Homeostasis

Cellular redox homeostasis is an essential and dynamic process that ensures the balance between reducing and oxidizing reactions within cells and regulates a plethora of biological responses and events. The study of these biochemical reactions has proven difficult over time, but recent technical and methodological developments have contributed to the rapid growth of the redox field and to our understanding of its importance in biology. The aim of this short review is to give the reader an overall understanding of redox regulation in the areas of cellular signaling, development, and disease, as well as to introduce some recent discoveries in those fields.

Diabetes and Cancer: Metabolic Association, Therapeutic Challenges, and the Role of Natural Products

Cancer is considered the second leading cause of death worldwide and in 2018 it was responsible for approximately 9.6 million deaths. Globally, about one in six deaths are caused by cancer. A strong correlation was found between diabetes mellitus and carcinogenesis with the most evident correlation was with type 2 diabetes mellitus (T2DM). Research has proven that elevated blood glucose levels take part in cell proliferation and cancer cell progression. However, limited studies were conducted to evaluate the efficiency of conventional therapies in diabetic cancer patients. In this review, the correlation between cancer and diabetes will be discussed and the mechanisms by which the two diseases interact with each other, as well as the therapeutics challenges in treating patients with diabetes and cancer with possible solutions to overcome these challenges. Natural products targeting both diseases were discussed with detailed mechanisms of action. This review will provide a solid base for researchers and physicians to test natural products as adjuvant alternative therapies to treat cancer in diabetic patients.

Effects of Black Raspberries and Their Ellagic Acid and Anthocyanin Constituents on Taxane Chemotherapy of Castration-Resistant Prostate Cancer Cells

Cancer patients often use dietary supplements while on therapy, but little is known about interactions of supplements with cancer chemotherapy. Black raspberries (BRB) have anti-cancer effects, but have not been evaluated for interference with chemotherapy for castrate-resistant prostate cancer (CRPC). Here we studied whether BRB and some of their constituents interact with docetaxel and cabazitaxel on CRPC cells in culture and implanted into nude mice. Ellagic acid increased, but BRB extract inhibited, microtubule assembly. Ellagic acid decreased tubulin polymerization by cabazitaxel and bound to tubulin. Ellagic acid, its metabolite urolithin A, BRB extract, and the anthocyanin metabolite protocatechuic acid (PCA) did not alter cytotoxicity of taxanes. Ellagic acid inhibited drug efflux in CRPC cells, but BRB extract and PCA did not. None of these compounds altered CYP3A4 activity. Although dietary ellagic acid did not alter the tumor growth inhibition by docetaxel of xenografted 22Rv1 cells, ellagic acid has the potential to interfere with taxane chemotherapy by reducing tubulin polymerization while inhibiting P-glycoprotein drug efflux. These data are cause for concern of consuming ellagic acid during treatment for CRPC and indicate need for further research, but BRB consumption appears safe.

Body Mass Index, Diet-Related Factors, and Bladder Cancer Prognosis: A Systematic Review and Meta-Analysis

Background

Urologists are frequently confronted with questions of urinary bladder cancer (UBC) patients about what they can do to improve their prognosis. Unfortunately, it is largely unknown which lifestyle factors can influence prognosis.

Objective

To systematically review the available evidence on the association between body mass index (BMI), diet, dietary supplements, and physical activity and UBC prognosis.

Methods

We searched PubMed and Embase up to May 2017. We included thirty-one articles reporting on observational and randomized controlled trials investigating BMI, diet and dietary supplements in relation to recurrence, progression, cancer-specific or all-cause mortality in UBC patients.

Results

In non-muscle invasive bladder cancer (NMIBC) patients, both overweight (3 studies, pooled hazard ratio (HR) 1.29, 95% CI 1.05-1.58, I² = 0%) as well as obesity (3 studies, pooled HR 1.82, 95% CI 1.12-2.95, I² = 79%) were associated with increased risk of recurrence when compared to normal weight. No association of BMI with risk of progression was found. Results for BMI and prognosis in muscle-invasive or in all stages series were inconsistent. Observational studies on diet and randomized controlled trials with dietary supplements showed inconsistent results. No studies on physical activity and UBC prognosis have been published to date.

Conclusions

Evidence for an association of lifestyle factors with UBC prognosis is limited, with some evidence for an association of BMI with risk of recurrence in NMIBC. Well-designed, prospective studies are needed to develop evidence-based guidelines on this topic.

Validity of a web-based dietary questionnaire designed especially to measure the intake of phyto-oestrogens

A diet questionnaire (DQ) designed to assess habitual diet and phyto-oestrogen intake was developed. This study aimed to examine the validity of the DQ in men, with and without having prostate cancer. The DQ was validated against alkylresorcinol metabolites measured in urine as objective biomarkers of whole grain wheat and rye (WG) intake, and a 4-d estimated food record (FR) was used for relative comparison. Participants (n 61) completed both methods and provided spot urine samples. We found a statistically significant correlation between the DQ and FR for reported whole grain intake and isoflavonoids, as well as for intake of macronutrients, except protein. The correlation coefficient between the two methods was on average r 0·30, lowest for lignans (r -0·11) and highest for alcohol (r 0·65). Reported energy intake was lower in the DQ compared with FR (8523 v. 9249 kJ (2037 v. 2211 kcal), respectively; P = 0·014). Bland-Altman plots showed an acceptable agreement; most cases were within the limits (95 % CI) of agreement on reported energy intake, as well as intake of macronutrients, except protein (which was underestimated in the DQ compared with the FR). The correlation of alkylresorcinol with WG intake was statistically significant in the DQ (r 0·31, P = 0·015), but not in the FR (r 0·18, P = 0·12) and the weighted κ was 0·29 and 0·11, respectively. In conclusion, the results showed that the DQ have a reasonable validity for measuring WG intake and most nutrients, and, after some adjustments regarding protein intake assessment have been made, the DQ will be a promising tool.

Metabolic rewiring in melanoma

Oncogene-driven metabolic rewiring is an adaptation to low nutrient and oxygen conditions in the tumor microenvironment that enables cancer cells of diverse origin to hyperproliferate. Aerobic glycolysis and enhanced reliance on glutamine utilization are prime examples of such rewiring. However, tissue of origin as well as specific genetic and epigenetic changes determines gene expression profiles underlying these metabolic alterations in specific cancers. In melanoma, activation of the mitogen-activated protein kinase (MAPK) pathway driven by mutant BRAF or NRAS is a primary cause of malignant transformation. Activity of the MAPK pathway, as well as other factors, such as HIF1α, Myc and MITF, are among those that control the balance between non-oxidative and oxidative branches of central carbon metabolism. Here, we discuss the nature of metabolic alterations that underlie melanoma development and affect its response to therapy.

No association between fiber intake and prostate cancer risk: a meta-analysis of epidemiological studies

Background

The findings of epidemiologic studies on the association between fiber intake and prostate cancer risk remain conflicting. We aimed to examine this association by conducting a meta-analysis of epidemiological studies.

Methods

Relevant studies were identified by PubMed (1966 to March 2015) and Embase (1974 to March 2015) database search through March 2015. We included epidemiological studies that reported relative risks (RRs) or odds ratios (ORs) with 95 % confidence intervals (CIs) for the association between dietary fiber intake and prostate cancer risk. Random effects models were used to calculate the summary risk estimates.

Results

For the highest compared with the lowest dietary fiber intake, a significantly decreased risk with prostate cancer was observed in case-control studies (OR = 0.82; 95 % CI, 0.68–0.96), but not in cohort studies (RR = 0.94; 95 % CI, 0.77–1.11). The combined risk estimate of all studies was 0.89 (95 % CI, 0.77, 1.01). A significant heterogeneity was observed across studies (p = 0.005). There was no evidence of significant publication bias based on Begg’s funnel plot (p = 0.753) or Egger’s test (p = 0.946).

Conclusions

This meta-analysis suggests the absence of evidence for association between dietary fiber intake and prostate cancer risk.

Dietary supplement use among cancer survivors of the NutriNet-Santé cohort study

Dietary supplements (DS) may influence cancer prognosis. Their use in cancer patients has been described in the United States, but data are largely lacking in Europe and notably in France. The present study's objectives were (1) to assess DS use and its sociodemographic, lifestyle, and dietary correlates in a large sample of French cancer survivors; (2) to evaluate the involvement of physicians in such DS use; and (3) to assess the extent of potentially harmful practices. Data were collected by self-administered web-based questionnaires among participants of the NutriNet-Santé cohort. Data on DS use was available for 1081 cancer survivors. DS users were compared to non-users with unconditional logistic regressions. DS use was reported by 62% of women and 29% of men. Vitamins D, B6, C and Mg were the most frequently consumed nutrients. 14% of cancer survivors initiated DS use after diagnosis. For 35% of the DS consumed, subjects did not inform their attending physician. DS use was associated with a healthier lifestyle (normal weight, never smoking and better diet) and substantially contributed to nutrient intake. 18% of DS users had potentially harmful DS use practices, such as the simultaneous use of vitamin E and anticoagulant/antiplatelet agents, the use of β-carotene and smoking or the use of phyto-oestrogens in hormone-dependent cancer patients. The present study suggests that DS use is widespread among cancer survivors, a large amount of that use is performed without any medical supervision and a substantial proportion of that use involves potentially harmful practices. Physicians should be encouraged to more routinely discuss DS use with their cancer patients.

Improving oral human papillomavirus detection using toothbrush sampling in HIV-positive men who have sex with men

Pre- and postabrasion oral rinse samples (ORS) and a toothbrush sample detected human papillomavirus (HPV) DNA in at least one sample among 45 (26%) of 173 HIV-positive men who have sex with men. There was moderate agreement for HPV genotype detection between the preabrasion and postabrasion ORS (κ = 0.49; 95% confidence interval [CI], 0.37 to 0.61). There was good agreement between postabrasion ORS and toothbrushes (κ = 0.70; 95% CI, 0.60 to 0.80). The sensitivities for HPV genotypes detected were 80% (95% CI, 69 to 88) for preabrasion ORS, 65% (95% CI, 54 to 76) for postabrasion ORS, and 75% (95% CI, 63 to 84) for toothbrushes.

Effect of soy protein isolate supplementation on biochemical recurrence of prostate cancer after radical prostatectomy: a randomized trial

IMPORTANCE

Soy consumption has been suggested to reduce risk or recurrence of prostate cancer, but this has not been tested in a randomized trial with prostate cancer as the end point.

OBJECTIVE

To determine whether daily consumption of a soy protein isolate supplement for 2 years reduces the rate of biochemical recurrence of prostate cancer after radical prostatectomy or delays such recurrence.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, double-blind trial conducted from July 1997 to May 2010 at 7 US centers comparing daily consumption of a soy protein supplement vs placebo in 177 men at high risk of recurrence after radical prostatectomy for prostate cancer. Supplement intervention was started within 4 months after surgery and continued for up to 2 years, with prostate-specific antigen (PSA) measurements made at 2-month intervals in the first year and every 3 months thereafter.

INTERVENTION

Participants were randomized to receive a daily serving of a beverage powder containing 20 g of protein in the form of either soy protein isolate (n=87) or, as placebo, calcium caseinate (n=90).

MAIN OUTCOMES AND MEASURES

Biochemical recurrence rate of prostate cancer (defined as development of a PSA level of ≥0.07 ng/mL) over the first 2 years following randomization and time to recurrence.

RESULTS

The trial was stopped early for lack of treatment effects at a planned interim analysis with 81 evaluable participants in the intervention group and 78 in the placebo group. Overall, 28.3% of participants developed biochemical recurrence within 2 years of entering the trial (close to the a priori predicted recurrence rate of 30%). Among these, 22 (27.2%) occurred in the intervention group and 23 (29.5%) in the placebo group. The resulting hazard ratio for active treatment was 0.96 (95% CI, 0.53-1.72; log-rank P = .89). Adherence was greater than 90% and there were no apparent adverse events related to supplementation.

CONCLUSION AND RELEVANCE

Daily consumption of a beverage powder supplement containing soy protein isolate for 2 years following radical prostatectomy did not reduce biochemical recurrence of prostate cancer in men at high risk of PSA failure.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00765479.

Mediterranean Diet Score and prostate cancer risk in a Swedish population-based case-control study

Several individual components of the Mediterranean diet have been shown to offer protection against prostate cancer. The present study is the first to investigate the association between adherence to the Mediterranean diet and the relative risk of prostate cancer. We also explored the usefulness of the Mediterranean Diet Score (MDS) in a non-Mediterranean population. FFQ data were obtained from 1482 incident prostate cancer patients and 1108 population-based controls in the Cancer of the Prostate in Sweden (CAPS) study. We defined five MDS variants with different components or using either study-specific intakes or intakes in a Greek reference population as cut-off values between low and high intake of each component. Unconditional logistic regression was used to estimate the relative risk of prostate cancer for high and medium v. low MDS, as well as potential associations with the individual score components. No statistically significant association was found between adherence to the Mediterranean diet based on any of the MDS variants and prostate cancer risk (OR range: 0·96-1·19 for total prostate cancer, comparing high with low adherence). Overall, we found little support for an association between the Mediterranean diet and prostate cancer in this Northern European study population. Despite potential limitations inherent in the study or in the build-up of a dietary score, we suggest that the original MDS with study-specific median intakes as cut-off values between low and high intake is useful in assessing the adherence to the Mediterranean diet in non-Mediterranean populations.

Fruit and vegetable intake and prostate cancer risk: a meta-analysis

AIMS

Recent reports have examined the effect of fruit and vegetable intake on the risk of prostate cancer, but the results are inconsistent. A meta-analysis of prospective studies was conducted to arrive at quantitative conclusions about the contribution of vegetable and fruit intake to the incidence of prostate cancer.

METHODS

A comprehensive, systematic search of medical literature published up to June 2012 was performed to identify relevant studies. Separate meta-analyses were conducted for fruit and vegetable consumption. The presence of publication bias was assessed using Egger and Begg tests.

RESULTS

In total, 16 cohort studies met the inclusion criteria and were included in the meta-analysis. The combined adjusted relative risk comparing highest with lowest categories showed that there was no association between vegetable and fruit consumption and prostate cancer incidence. The pooled relative risk was 0.97 (95%CI 0.93, 1.01) for vegetables and 1.02 (95%CI 0.98, 1.07) for fruit. There is no heterogeneity between the studies. No publication bias was detected.

CONCLUSION

This meta-analysis suggests that total fruit or vegetable consumption may not exert a protective role in the risk of prostate cancer.

The Nordic Nutrition Recommendations and prostate cancer risk in the Cancer of the Prostate in Sweden (CAPS) study

OBJECTIVE

The Nordic Nutrition Recommendations (NNR) aim at preventing diet-associated diseases such as cancer in the Nordic countries. We evaluated adherence to the NNR in relation to prostate cancer (PC) in Swedish men, including potential interaction with a genetic risk score and with lifestyle factors.

DESIGN

Population-based case-control study (Cancer of the Prostate in Sweden (CAPS), 2001-2002). Using data from a semi-quantitative FFQ, we created an NNR adherence score and estimated relative risks of PC by unconditional logistic regression. Individual score components were modelled separately and potential modifying effects were assessed on the multiplicative scale.

SETTING

Four regions in the central and northern parts of Sweden.

SUBJECTS

Incident PC patients (n 1386) and population controls (n 940), frequency-matched on age and region.

RESULTS

No overall association with PC was found, possibly due to the generally high adherence to the NNR score and its narrow distribution in the study population. Among individual NNR score components, high compared with low intakes of polyunsaturated fat were associated with an increased relative risk of localized PC. No formal interaction with genetic or lifestyle factors was observed, although in stratified analysis a positive association between the NNR and PC was suggested among men with a high genetic risk score but not among men with a medium or low genetic risk score.

CONCLUSIONS

Our findings do not support an association between NNR adherence and PC. The suggestive interaction with the genetic risk score deserves further investigations in other study populations.