Phase II prospective randomized trial of a low-fat diet with fish oil supplementation in men undergoing radical prostatectomy

A phase IIb randomized placebo-controlled trial testing the effect of MAG-EPA long-chain omega-3 fatty acid dietary supplement on prostate cancer proliferation

BACKGROUND

High prostate eicosapentaenoic fatty acid (EPA) levels were associated with a significant reduction of upgrading to grade group (GG) ≥ 2 prostate cancer in men under active surveillance. We aimed to evaluate the effect of MAG-EPA long-chain omega-3 fatty acid dietary supplement on prostate cancer proliferation.

METHODS

A phase II double-blind randomized placebo-controlled trial was conducted in 130 men diagnosed with GG ≥ 2 prostate cancer and undergoing radical prostatectomy between 2015-2017 (Clinicaltrials.gov: NCT02333435). Participants were randomized to receive 3 g daily of either MAG-EPA (n = 65) or placebo (n = 65) for 7 weeks (range 4-10) prior to radical prostatectomy. The primary outcome was the cancer proliferation index quantified by automated image analysis of tumor nuclear Ki-67 expression using standardized prostatectomy tissue microarrays. Additional planned outcomes at surgery are reported including plasma levels of 27 inflammatory cytokines and fatty acid profiles in circulating red blood cells membranes and prostate tissue.

RESULTS

Cancer proliferation index measured by Ki-67 expression was not statistically different between the intervention (3.10%) and placebo (2.85%) groups (p = 0.64). In the per protocol analyses, the adjusted estimated effect of MAG-EPA was greater but remained non-significant. Secondary outcome was the changes in plasma levels of 27 cytokines, of which only IL-7 was higher in MAG-EPA group compared to placebo (p = 0.026). Men randomized to MAG-EPA prior to surgery had four-fold higher EPA levels in prostate tissue compared to those on placebo.

CONCLUSIONS

This MAG-EPA intervention did not affect the primary outcome of prostate cancer proliferation according to nuclear Ki-67 expression. More studies are needed to decipher the effects of long-chain omega-3 fatty acid dietary supplementation in men with prostate cancer.

Effect of omega-3 fatty acid diet on prostate cancer progression and cholesterol efflux in tumor-associated macrophages-dependence on GPR120

BACKGROUND

Preclinical and clinical translational research supports the role of an ω-3 fatty acid diet for prostate cancer prevention and treatment. The anti-prostate cancer effects of an ω-3 diet require a functional host g-protein coupled receptor 120 (GPR120) but the underlying effects on the tumor microenvironment and host immune system are yet to be elucidated.

METHODS

Friend leukemia virus B (FVB) mice received bone marrow from green fluorescent protein (GFP) labeled GPR120 wild-type (WT) or knockout (KO) mice followed by implanting Myc-driven mouse prostate cancer (MycCap) allografts and feeding an ω-3 or ω-6 diet. Tumor associated immune cells were characterized by flow cytometry, and CD206+ tumor infiltrating M2-like macrophages were isolated for gene expression studies. MycCap prostate cancer cell conditioned medium (CM) was used to stimulate murine macrophage cells (RAW264.7) and bone marrow-derived (BMD) macrophages to study the effects of docosahexanoic acid (DHA, fish-derived ω-3 fatty acid) on M2 macrophage function and cholesterol metabolism.

RESULTS

The bone marrow transplantation study showed that an ω-3 as compared to an ω-6 diet inhibited MycCaP allograft tumor growth only in mice receiving GPR120 WT but not GPR120 KO bone marrow. In the ω-3 group, GPR120 WT BMD M2-like macrophages infiltrating the tumor were significantly reduced in number and gene expression of cholesterol transporters Abca1, Abca6, and Abcg1. RAW264.7 murine macrophages and BMDMs exposed to MycCaP cell CM had increased gene expression of cholesterol transporters, depleted cholesterol levels, and were converted to the M2 phenotype. These effects were inhibited by DHA through the GPR120 receptor.

CONCLUSION

Host bone marrow cells with functional GPR120 are essential for the anticancer effects of dietary ω-3 fatty acids, and a key target of the ω-3 diet are the M2-like CD206+ macrophages. Our preclinical findings provide rationale for clinical trials evaluating ω-3 fatty acids as a potential therapy for prostate cancer through inhibition of GPR120 functional M2-like macrophages.

Physical activity and dietary considerations for prostate cancer patients: future research directions

This review considers current evidence on physical activity and dietary behaviours in the context of prostate cancer prevention and survivorship outcomes. Prostate cancer is the second most common cancer amongst men, with over 1⋅4 million newly diagnosed cases globally each year. Due to earlier detection via screening and advances in treatments, survival rates are amongst the highest of all cancer populations. However, hormone treatments (i.e. androgen deprivation therapy) can lead to undesirable body composition changes, increased fatigue and reduced health-related quality of life, which can impair the overall wellbeing of men living with and beyond prostate cancer. Existing research has only provided limited evidence that physical activity and nutrition can impact a man's risk of prostate cancer but cohort studies suggest they can influence survival outcomes after diagnosis. Additionally, data from observational and intervention studies suggest that habitual physical activity (or structured exercise) and healthy diets can help to ameliorate hormone-related treatment side-effects. Current physical activity guidelines state that prostate cancer patients should complete at least three sessions of moderate-intensity aerobic exercise per week, along with two resistance exercise sessions, but dietary guidelines for prostate cancer patients are less well defined. In conclusion, regular physical activity and nutritional interventions may improve survival outcomes and attenuate some adverse side-effects of hormone treatments in men with prostate cancer. However, further research is required to improve our understanding of the health impacts of physical activity (including structured exercise) and nutrition in relation to prostate cancer prevention and survivorship.

The Role of Specialized Pro-Resolving Lipid Mediators in Inflammation-Induced Carcinogenesis

Cancer is a process involving cell mutation, increased proliferation, invasion, and metastasis. Over the years, this condition has represented one of the most concerning health problems worldwide due to its significant morbidity and mortality. At present, the incidence of cancer continues to grow exponentially. Thus, it is imperative to open new avenues in cancer research to understand the molecular changes driving DNA transformation, cell-to-cell interaction derangements, and immune system surveillance decay. In this regard, evidence supports the relationship between chronic inflammation and cancer. In light of this, a group of bioactive lipids derived from polyunsaturated fatty acids (PUFAs) may have a position as novel anti-inflammatory molecules known as the specialized pro-resolving mediators (SPMs), a group of pro-resolutive inflammation agents that could improve the anti-tumor immunity. These molecules have the potential role of chemopreventive and therapeutic agents for various cancer types, and their effects have been documented in the scientific literature. Thus, this review objective centers around understanding the effect of SPMs on carcinogenesis and their potential therapeutic effect.

Effects of dietary omega-3 fatty acids on orthotopic prostate cancer progression, tumor associated macrophages, angiogenesis and T-cell activation-dependence on GPR120

BACKGROUND

The antiprostate cancer effects of dietary ω-3 fatty acids (FAs) were previously found to be dependent on host G-protein coupled receptor 120 (GPR120). Using an orthotopic tumor model and an ex-vivo model of bone marrow derived M2-like macrophages, we sought to determine if ω-3 FAs inhibit angiogenesis and activate T-cells, and if these effects are dependent on GPR120.

METHODS

Gausia luciferase labeled MycCaP prostate cancer cells (MycCaP-Gluc) were injected into the anterior prostate lobe of FVB mice. After established tumors were confirmed by blood luminescence, mice were fed an ω-3 or ω-6 diet. Five weeks after tumor injection, tumor weight, immune cell infiltration and markers of angiogenesis were determined. An ex-vivo co-culture model of bone marrow derived M2-like macrophages from wild-type or GPR120 knockout mice with MycCap prostate cancer cells was used to determine if docosahexanoic acid (DHA, ω-3 FA) inhibition of angiogenesis and T-cell activation is dependent on macrophage GPR120.

RESULTS

Feeding an ω-3 diet significantly reduced orthotopic MycCaP-Gluc tumor growth relative to an ω-6 diet. Tumors from the ω-3 group had decreased M2-like macrophage infiltration and decreased expression of angiogenesis factors. DHA significantly inhibited M2 macrophage-induced endothelial tube formation and reversed M2 macrophage-induced T-cell suppression, and these DHA effects were mediated, in part, by M2 macrophage GPR120.

CONCLUSION

Omega-3 FAs delayed orthotopic tumor growth, inhibited M2-like macrophage tumor infiltration, and inhibited M2-like macrophage-induced angiogenesis and T-cell suppression. Given the central role of M2-like macrophages in prostate cancer progression, GPR120-dependent ω-3 FA inhibition of M2-like macrophages may play an important role in prostate cancer therapeutics.

Developing dietary interventions as therapy for cancer

Cancer cells acquire distinct metabolic preferences based on their tissue of origin, genetic alterations and degree of interaction with systemic hormones and metabolites. These adaptations support the increased nutrient demand required for increased growth and proliferation. Diet is the major source of nutrients for tumours, yet dietary interventions lack robust evidence and are rarely prescribed by clinicians for the treatment of cancer. Well-controlled diet studies in patients with cancer are rare, and existing studies have been limited by nonspecific enrolment criteria that inappropriately grouped together subjects with disparate tumour and host metabolic profiles. This imprecision may have masked the efficacy of the intervention for appropriate candidates. Here, we review the metabolic alterations and key vulnerabilities that occur across multiple types of cancer. We describe how these vulnerabilities could potentially be targeted using dietary therapies including energy or macronutrient restriction and intermittent fasting regimens. We also discuss recent trials that highlight how dietary strategies may be combined with pharmacological therapies to treat some cancers, potentially ushering a path towards precision nutrition for cancer.

Dietary fish and omega-3 polyunsaturated fatty acids intake and cancer survival: A systematic review and meta-analysis

Fish and omega-3 polyunsaturated fatty acids (PUFA) have been suggested to play a role in improving cancer prognosis. However, results from epidemiological studies remain inconsistent. Here we assess the association between dietary fish and/or omega-3 PUFAs intake and cancer prognosis with meta-analysis of observational studies. A systematic search of related publications was performed using PubMed and Web of Science databases. Hazard ratios (HR) and 95% confidence intervals (CI) were extracted and then pooled using a random-effect model. Potential linear and non-linear dose-response relationships were explored using generalized least squares estimation and restricted cubic splines. As a result, 21 cohort studies were included in our analysis. Compared to the lowest category, the highest category of fish intake was associated with a significant lower mortality in patients with ovarian cancer (n = 1, HR = 0.74, 95% CI: 0.57-0.95) and overall cancer (n = 12, HR = 0.87, 95% CI: 0.81-0.94). Marine omega-3 PUFAs intake rather than total omega-3 PUFAs intake showed significant protective effects on survival of overall cancer (n = 8, HR = 0.81, 95% CI: 0.71-0.94), in particular prostate cancer (n = 2, HR = 0.62, 95% CI: 0.46-0.82). Dose-response meta-analysis indicated a nonlinear and a linear relationship between fish intake, as well as marine omega-3 PUFAs intake, and overall cancer survival, respectively. In conclusion, our analysis demonstrated a protective effect of dietary fish and marine omega-3 PUFAs consumption on cancer survival.

Correlative Analysis of Vitamin D and Omega-3 Fatty Acid Intake in Men on Active Surveillance for Prostate Cancer

OBJECTIVE

To investigate the influence of targeted serum vitamin-D level and omega-6:3 fatty-acid ratio on prostate-specific antigen (PSA) level in men with prostate cancer managed with active surveillance by providing a nutritional intervention and vitamin supplementation.

METHODS

Sixty-eight patients with biopsy-proven National Comprehensive Cancer Network very-low or low-risk prostate cancer were enrolled in the prostate cancer nutrition and genetics clinic at the Cleveland Clinic from July 2013-December 2019. Patients adhered to a specific dietary regimen devoid of animal-based products and foods containing omega-6 polyunsaturated fatty acids (PUFAs). The supplement regimen consisted of: Omega-3 PUFAs 720mg (3/day); curcumin 2000 mg/day; vitamin D3 dose titrated to achieve serum level of 60 ng/ml; and vitamin B-complex 1000 mg (4 times weekly). Patients underwent periodic monitoring of PSA, serum vitamin D, and PUFA levels and had frequent follow-up with the nutritionist which included a food frequency questionnaire. Interval prostate biopsy was performed as clinically indicated and/or at 9 months.

RESULTS

The mean and 95% confidence interval of PSA slope and Vitamin D serum levels slope were 0.11 (0-0.25) ng/mL/month and 4.65 (3.09-5.98) ng/mL/month, respectively. Patients with higher initial vitamin D levels were twice as likely to have a downward PSA trend (OR = 2.04, 95% confidence interval 1.04-4.01, P = .04). Fifty-five patients underwent follow-up biopsy, all showing no progression of disease. Three patients had loose bowel movements that required omega-3 and or curcumin dose adjustments.

CONCLUSION

Intensive nutritional intervention with Vitamin D and Omega-3 PUFA supplementation may benefit men on active surveillance for prostate cancer and further studies are warranted.

Long chain omega-3 fatty acids and their oxidized metabolites are associated with reduced prostate tumor growth

INTRODUCTION

Cancer has been associated with increased oxidative stress and deregulation of bioactive oxylipins derived from long-chain polyunsaturated fatty acids (LC-PUFA) like arachidonic acid (AA). There is a debate whether ω-3 LC-PUFA could promote or prevent prostate tumor growth through immune modulation and reduction of oxidative stress. Our aim was to study the association between enzymatically or non-enzymatically produced oxidized-LC-PUFA metabolites and tumor growth in an immune-competent eugonadal and castrated C57BL/6 male mice injected with TRAMP-C2 prostate tumor cells, fed with ω-3 or ω-6 LC-PUFA-rich diets.

MATERIALS AND METHODS

Tumor fatty acids were profiled by gas chromatography and 26 metabolites derived from either AA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were assessed by liquid chromatography-mass spectrometry.

RESULTS

The enriched ω-3 diet did not reduce oxidative stress overall in tumors but favored the formation of ω-3 rather than ω-6 derived isoprostanoids. We discovered that EPA and its oxidized-derivatives like F₃-isoprostanes and prostaglandin (PG)F_3α, were inversely correlated with tumor volume (spearman correlations and T-test, p<0.05). In contrast, F₂-isoprostanes, adrenic acid, docosapentaenoic acid (DPA_ω-6) and PGE₂ were positively correlated with tumor volume. Interestingly, F₄-neuroprostanes, PGD₂, PGF_2α, and thromboxane were specifically increased in TRAMP-C2 tumors of castrated mice compared to those of eugonadal mice.

DISCUSSION

Decreasing tumor growth under ω-3 diet could be attributed in part to increased levels of EPA and its oxidized-derivatives, a reduced level of pro-angiogenic PGE₂ and increased levels of F₄-neuroprostanes and resolvins content in tumors, suspected of having anti-proliferative and anti-inflammatory effects.

Omega-3 Eicosapentaenoic Acid Reduces Prostate Tumor Vascularity

The impact of omega (ω)-3 fatty acids on prostate cancer is controversial in epidemiological studies but experimental studies suggest a protective effect. However, little is known about the mechanism of action. Here, we studied the effects of purified fatty acid molecules on prostate tumor progression using the TRAMP-C2 syngeneic immunocompetent mouse model. Compared with ω-6 or ω-9-supplemented animals, we observed that late-stage prostate tumor growth was reduced with a monoacylglyceride (MAG)-conjugated form of eicosapentaenoic acid (EPA) supplementation, whereas docosahexanenoic acid (DHA) caused an early reduction. MAG-EPA significantly decreased tumor blood vessel diameter (P < 0.001). RNA sequencing analysis revealed that MAG-EPA downregulated angiogenesis- and vascular-related pathways in tumors. We also observed this tissue vascular phenotype in a clinical trial testing MAG-EPA versus a high oleic sunflower oil placebo. Using anti-CD31 IHC, we observed that MAG-EPA reduced blood vessel diameter in prostate tumor tissue (P = 0.03) but not in normal adjacent tissue. Finally, testing autocrine and paracrine effects in an avascular tumor spheroid growth assay, both exogenous MAG-EPA and endogenous ω3 reduced VEGF secretion and in vitro endothelial cell tube formation and blocked tumor spheroid growth, suggesting that ω3 molecules can directly hinder prostate cancer cell growth. Altogether, our results suggest that fatty acids regulate prostate cancer growth and that a tumor-specific microenvironment is required for the anti-vascular effect of MAG-EPA in patients with prostate cancer. IMPLICATIONS: Increasing the amount of ingested EPA omega-3 subtype for patients with prostate cancer might help to reduce prostate tumor progression by reducing tumor vascularization.

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.

Role of Host GPR120 in Mediating Dietary Omega-3 Fatty Acid Inhibition of Prostate Cancer

Background

GPR120, a G protein-coupled receptor for long-chain polyunsaturated fatty acids (FAs), mediates the anti-inflammatory effects of omega-3 (ω-3) FAs. We investigated whether host or tumor GPR120 plays a role in the anti-prostate cancer effects of ω-3 FAs.

Methods

MycCap prostate cancer allografts were grown in immunocompetent wild-type (WT) and GPR120 knockout (KO) mice fed ω-3 (fish oil) or ω-6 (corn oil) diets. Immune cell infiltration was quantified by flow cytometry, and gene expression of immune cell markers in isolated tumor-associated macrophages (TAMs) was quantified by quantitative real-time polymerase chain reaction. Archived tissue from a fish oil intervention trial was used to correlate gene expression of GPR120 with cell cycle progression (CCP) genes and Ki67 index (n = 11-15 per group). All statistical tests were two-sided.

Results

In WT mice (n = 7 per group), dietary ω-3 FAs decreased MycCap allograft tumor growth (mean [SD] final tumor volume ω-6 = 491 [437] mm3 vs ω-3 = 127 [77] mm3, P = .04), whereas in global GPR120KO mice (n = 7 per group) ω-3 FAs had no anticancer effects. Dietary ω-3 FAs inhibited GPR120KO-MycCaP allografts grown in WT mice (n = 8 per group; mean [SD] final tumor volume ω-6 = 776 [767] mm3 vs ω-3 = 36 [34] mm3, P = .02). Omega-3 FA treatment decreased the number of M2-like TAMs in tumor tissue and gene expression of M2 markers in isolated TAMs compared with ω-6 controls in WT (n = 7 per group) but not in GPR120KO mice (n = 7 per group). In human tissue, higher expression of stromal GPR120 correlated with greater reduction in expression of CCP genes in men with prostate cancer on a high-ω-3 diet (r = -.57, P = .04).

Conclusions

Host GPR120 plays a central role in the anti-prostate cancer effects of dietary ω-3 FAs. Future studies are required to determine if the anticancer effects of ω-3 FAs are mediated through inhibition of M2-like macrophages and if host GPR120 status predicts anticancer effects of dietary ω-3 FAs in men with prostate cancer.

Trends in Complementary and Alternative Medicine Use among Patients with Prostate Cancer

PURPOSE

We explored the prevalence and trends of self-reported complementary and alternative medicine use among patients with prostate cancer using CaPSURE™ (Cancer of the Prostate Strategic Urologic Research Endeavor).

MATERIALS AND METHODS

A total of 7,989 CaPSURE participants completed questionnaires between 1996 and 2016 on the use of nearly 70 complementary and alternative medicine types. Participants were defined as users if they indicated that they had ever used complementary and alternative medicines. To evaluate trends among 7,696 patients with newly diagnosed prostate cancer we considered complementary and alternative medicine use within 24 months of diagnosis and calculated the percent change in complementary and alternative medicine use between groups defined by the year of diagnosis.

RESULTS

Of patients with prostate cancer 56% reported complementary and alternative medicine use on at least 1 questionnaire. Multivitamin and omega-3 fatty acid use was common at 40% and 24% of patients, respectively. Compared to nonusers greater proportions of complementary and alternative medicine users were college educated, had a higher household income and lived in the West and Midwest. Median prostate specific antigen at diagnosis was 5.8 (IQR 4.4-8.4) and 6.2 ng/ml (IQR 4.7-10.1) among users and nonusers, respectively (p <0.01). Between those diagnosed in 1996 to 2000 and 2011 to 2016, complementary and alternative medicine use increased 128% from 24% to 54%. When comparing participants diagnosed in 2006 to 2010 with those diagnosed in 2011 to 2016, a 108% increase was seen in supplemental vitamin D use and a -48% decrease was seen in supplemental vitamin E use.

CONCLUSIONS

Many patients with prostate cancer reported complementary and alternative medicine use. Multivitamins and omega-3 fatty acids were commonly ingested and vitamin D use increased dramatically from 2006 to 2010 compared to 2011 to 2016. These data can guide clinical discussions and decision making such as nutritionist referral and help prioritize future research.

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.

Omega-3 Fatty Acids Survey in Men under Active Surveillance for Prostate Cancer: from Intake to Prostate Tissue Level

Dietary omega-3 fatty acids (ω3), particularly long-chain ω3 (LCω3), have protective effects against prostate cancer (PCa) in experimental studies. Observational studies are conflicting, possibly because of the biomarker used. This study aimed at evaluating associations between grade reclassification and ω3 levels assessed in prostatic tissue, red blood cells (RBC), and diet. We conducted a validation cross-sectional study nested within a phase II clinical trial. We identified 157 men diagnosed with low-risk PCa who underwent a first active surveillance repeat prostate biopsy session. Fatty acid (FA) intake was assessed using a food frequency questionnaire and their levels measured in prostate tissue and RBC. Associations were evaluated using logistic regression. At first repeat biopsy session, 39 (25%) men had high-grade PCa (grade group ≥2). We found that high LCω3-eicosapentaenoic acid (EPA) level in prostate tissue (odds ratio (OR) 0.25; 95% (confidence interval (CI) 0.08–0.79; p-trend = 0.03) was associated with lower odds of high-grade PCa. Similar results were observed for LCω3 dietary intake (OR 0.30; 95% CI 0.11-0.83; p-trend = 0.02) but no association for RBC. LCω3-EPA levels in the target prostate tissue are inversely associated with high-grade PCa in men with low-risk PCa, supporting that prostate tissue FA, but not RBC FA, is a reliable biomarker of PCa risk.

Randomized trial evaluating the role of weight loss in overweight and obese men with early stage prostate Cancer on active surveillance: Rationale and design of the Prostate Cancer Active Lifestyle Study (PALS)

Active surveillance (AS) is increasingly used to monitor patients with low-risk prostate cancer; however, approximately 50% of AS patients experience disease reclassification requiring definitive treatment and little is known about patient characteristics that modify the risk of reclassification. Obesity may be one of the major contributing factors. The Prostate Cancer Active Lifestyle Study (PALS) is a clinical trial evaluating the impact of weight loss among overweight/obese (Body Mass Index (BMI) ≥ 25 kg/m2) men with clinically localized prostate cancer on AS. Two hundred participants will be randomized to either the PALS intervention, a 6-month structured diet and exercise program adapted from the Diabetes Prevention Program followed by 6 months of maintenance, or control (general diet and physical activity guidelines delivered in a single session). The PALS intervention involves one-on-one instruction with a registered dietitian and exercise physiologist to achieve the study goal of loss of 7% of baseline weight. Participation is coordinated so that the 6-month time point coincides with the participants' standard-of-care AS prostate biopsy. Primary outcomes will evaluate the intervention effects on circulating and tissue markers of glucose and insulin regulation, health-related quality of life and pathologic upgrading on follow-up prostate biopsies. Additional analyses will determine whether changes in weight and glucose regulation can be sustained for 6 months after the end of instruction. Findings from this trial may have wide reaching implications for men diagnosed with clinically-localized prostate cancer by providing an active lifestyle-based approach to improve prostate cancer patient outcomes.

Omega-3 fatty acids decrease prostate cancer progression associated with an anti-tumor immune response in eugonadal and castrated mice

BACKGROUND

Several lines of evidence suggest effects of dietary fat on prostate cancer (PCa) development and progression. Targeting omega (ω)-3:ω6 fatty acids (FA) ratio could be beneficial against PCa by favorably modulating inflammation. Here, we studied the effects of ω3- and ω6-enriched diets on prostate tumor growth and inflammatory response in androgen-deprived and non-deprived conditions.

METHODS

Immune-competent eugonadal and castrated C57BL/6 mice were injected with TRAMP-C2 prostate tumor cells and daily fed with ω3- or ω6-enriched diet. FA and cytokine profiles were measured in blood and tumors using gas chromatography and multiplex immunoassay, respectively. Immune cell infiltration in tumors was profiled by multicolor flow cytometry.

RESULTS

ω3-enriched diet decreased prostate TRAMP-C2 tumor growth in immune-competent eugonadal and castrated mice. Cytokines associated with Th1 immune response (IL-12 [p70], IFN-γ, GM-CSF) and eosinophil recruitment (eotaxin-1, IL-5, and IL-13) were significantly elevated in tumors of ω3-fed mice. Using in vitro experiments, we confirmed ω3 FA-induced eotaxin-1 secretion by tumor cells and that eotaxin-1 secretion was regulated by androgens. Analysis of immune cell infiltrating tumors showed no major difference of immune cells' abundance between ω3- and ω6-enriched diets.

CONCLUSIONS

ω3-enriched diet reduces prostate tumor growth independently of androgen levels. ω3 FA can inhibit tumor cell growth and induce a local anti-tumor inflammatory response. These findings warrant further examination of dietary ω3's potential to slow down the progression of androgen-sensitive and castrate-resistant PCa by modulating immune cell function in tumors.

New insights on the regulation of cancer cachexia by N-3 polyunsaturated fatty acids

Cancer cachexia is a multifactorial syndrome that develops during malignant tumor growth. Changes in plasma levels of several hormones and inflammatory factors result in an intense catabolic state, decreased activity of anabolic pathways, anorexia, and marked weight loss, leading to cachexia development and/or accentuation. Inflammatory mediators appear to be related to the control of a highly regulated process of muscle protein degradation that accelerates the process of cachexia. Several mediators have been postulated to participate in this process, including TNF-α, myostatin, and activated protein degradation pathways. Some interventional therapies have been proposed, including nutritional (dietary, omega-3 fatty acid supplementation), hormonal (insulin), pharmacological (clenbuterol), and nonpharmacological (physical exercise) therapies. Omega-3 (n-3) polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid, are recognized for their anti-inflammatory properties and have been used in therapeutic approaches to treat or attenuate cancer cachexia. In this review, we discuss recent findings on cellular and molecular mechanisms involved in inflammation in the cancer cachexia syndrome and the effectiveness of n-3 PUFAs to attenuate or prevent cancer cachexia.

An Integrative Approach to Prostate Cancer

OBJECTIVES

The mostly indolent natural history and long overall survival associated with a diagnosis of prostate cancer provides a unique opportunity for men to explore diet and lifestyle interventions to alter the trajectory of their disease. As many patients may be appropriate for postponing conventional therapy, the effects of various integrative interventions can be investigated. In addition, treatment of prostate cancer with surgery, radiation, or androgen deprivation therapy, all may produce physical or psychological side effects that could be amenable to complementary therapies. This article serves to review salient information in the published literature.

DESIGN

A review of published research was conducted.

RESULTS

A plant-based antioxidant-rich diet with an emphasis on cruciferous vegetables, tomatoes, soy, pomegranate, and marine omega 3 fatty acids while avoiding saturated fats, including dairy products is the best option. Supplementation with vitamin D3, omega 3, and some nutraceutical-based preparations may be advised. It is likely prudent to avoid vitamin E and selenium supplements. Physical activity has been shown to have multiple benefits in men diagnosed with all stages of prostate cancer from strengthening bones, improving body habitus, and enhancing overall wellbeing. Yoga, combining physical activity with a mind-body component, has been shown to have a salutogenic effect in both prostate cancer patients and their caregivers. Traditional Chinese Medicine may be particularly useful in managing side effects of conventional treatments, especially the hot flashes associated with androgen deprivation therapy. Although the long natural history, availability of a useful blood marker of disease progression and prolonged survival are overall positive features, they also combine to allow men to live for a long time with diagnosed cancer, fear of progression, or recurrence and fixation on changes in their prostate-specific antigen level. The resultant stress can be deleterious to general health as well as possibly the natural history of their disease. Mind-body interventions to reduce stress, including mindfulness-based stress reduction and support groups may be useful adjunctive therapies.

CONCLUSION

Men with prostate cancer may benefit from lifestyle and complementary interventions integrated with their conventional care.

Translating Mechanism-Based Strategies to Break the Obesity-Cancer Link: A Narrative Review

Prevalence of obesity, an established risk factor for many cancers, has increased dramatically over the past 50 years in the United States and across the globe. Relative to normoweight cancer patients, obese cancer patients often have poorer prognoses, resistance to chemotherapies, and are more likely to develop distant metastases. Recent progress on elucidating the mechanisms underlying the obesity-cancer connection suggests that obesity exerts pleomorphic effects on pathways related to tumor development and progression and, thus, there are multiple opportunities for primary prevention and treatment of obesity-related cancers. Obesity-associated alterations, including systemic metabolism, adipose inflammation, growth factor signaling, and angiogenesis, are emerging as primary drivers of obesity-associated cancer development and progression. These obesity-associated host factors interact with the intrinsic molecular characteristics of cancer cells, facilitating several of the hallmarks of cancer. Each is considered in the context of potential preventive and therapeutic strategies to reduce the burden of obesity-related cancers. In addition, this review focuses on emerging mechanisms behind the obesity-cancer link, as well as relevant dietary interventions, including calorie restriction, intermittent fasting, low-fat diet, and ketogenic diet, that are being implemented in preclinical and clinical trials, with the ultimate goal of reducing incidence and progression of obesity-related cancers.

Effects of concentrated long-chain omega-3 polyunsaturated fatty acid supplementation before radical prostatectomy on prostate cancer proliferation, inflammation, and quality of life: study protocol for a phase IIb, randomized, double-blind, placebo-controlled trial

BACKGROUND

Prostate cancer is the most commonly diagnosed cancer in north-American men. Few dietary or lifestyle interventions have been tested to prevent prostate cancer progression. Omega-3 fatty acid supplementation represents a promising intervention for prostate cancer patients. The aim of the study is to evaluate the effects of long-chain omega-3 polyunsaturated fatty acids (LCn3), more precisely eicosapentaenoic acid monoacylglyceride (MAG-EPA) supplementation, on prostate cancer proliferation, inflammation mediators and quality of life among men who will undergo radical prostatectomy.

METHODS/DESIGN

We propose a phase IIb, randomized, double-blind placebo-controlled trial of MAG-EPA supplementation for 130 men who will undergo radical prostatectomy as treatment for a prostate cancer of Gleason score ≥ 7 in an academic cancer center in Quebec City. Participants will be randomized to 6 capsules of 625 mg of fish oil (MAG-EPA) per capsule containing 500 mg of EPA daily or to identically looking capsules of high oleic acid sunflower oil (HOSO) as placebo. The intervention begins 4 to 10 weeks prior to radical prostatectomy (baseline) and continues for one year after surgery. The primary endpoint is the proliferative index (Ki-67) measured in prostate cancer cells at radical prostatectomy. A secondary endpoint includes prostate tissue levels of inflammatory mediators (cytokines and proteins) at time of radical prostatectomy. Changes in blood levels of inflammatory mediators, relative to baseline levels, at time of radical prostatectomy and 12 months after radical prostatectomy will also be evaluated. Secondary endpoints also include important aspects of psychosocial functioning and quality of life such as depression, anxiety, sleep disturbances, fatigue, cognitive complaints and prostate cancer-specific quality of life domains. The changes in these outcomes, relative to baseline levels, will be evaluated at 3, 6, 9 and 12 months after radical prostatectomy.

DISCUSSION

The results from this trial will provide crucial information to clarify the role of omega-3 supplementation on prostate cancer proliferation, inflammation and quality of life.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02333435. Registered on December 17, 2014. Last updated September 6, 2016.

Plasma Fatty Acids as Surrogate for Prostate Levels

Inconsistent results from epidemiologic studies of circulating fatty acids and prostate cancer risk may be partly due to use of blood concentrations as surrogate biomarkers of prostate tissue concentrations. To determine whether blood concentrations reflect prostate tissue fatty acid profiles, we evaluated associations between phospholipid fatty acid (PLFA) profiles measured in plasma and prostate tissue from 20 patients who underwent prostatectomy. For each patient, three prostate tissue specimens varying in size and location were collected. Correlations were calculated between a) tissue specimens by size ( ≤ 20 mg, > 20 mg); b) individual tissue samples [Intraclass Correlation Coefficient (ICC)]; and c) plasma and mean tissue PLFA concentrations. PLFA concentrations from ≤ 20 mg and > 20 mg tissues were nearly identical. For most PLFAs, intra-individual correlations between tissue specimens were moderate to strong (linoleic acid = 0.66, eicosapentaenoic acid = 0.96), with only one ICC below 0.50 (trans-fatty acid 18:2, ICC = 0.28). Most correlations of mean tissue and plasma concentrations were moderate to strong (α-linoleic acid = 0.47, eicosapentaenoic acid = 0.93). PLFA concentrations are largely homogeneous within the prostate and can be reliably measured in small quantities of tissue. The overall strong correlations between plasma and tissue suggest that for most individual PLFAs, plasma concentrations are adequate surrogate markers of prostate tissue concentrations.

Long-chain n-3 PUFA against breast and prostate cancer: Which are the appropriate doses for intervention studies in animals and humans?

The potential antineoplastic effect of the long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) remains a highly controversial issue. Numerous animal studies have supported the anticancer role of these dietary fatty acids, whereas conflicting results have been obtained in population studies, and only a few intervention human trials have been so far performed. In view of the possibility that the anticancer effects may be maximally observed within a defined range of EPA and DHA doses, herein we critically review the results and doses used in both animal studies and human clinical trials focusing on the possible n-3 PUFA protective effects against breast and prostate cancer. Our main aim is to identify the EPA and/or DHA ranges of doses needed to obtain clear anticancer effects. This may be of great help in designing future animal studies, and also in understanding the most appropriate dose for further human intervention studies. Moreover, since the healthy effects of these fatty acids have been strictly related to their increased incorporation in plasma and tissue lipids, we also examine and discuss the incorporation changes following the administration of the effective anticancer EPA and/or DHA doses in animals and humans.

Involvement of apoptotic pathways in docosahexaenoic acid-induced benefit in prostate cancer: Pathway-focused gene expression analysis using RT2 Profile PCR Array System

Background

Present study aimed to better understand the potential apoptotic pathways that involved in docosahexaenoic acid (DHA)-induced apoptosis of prostate cancer cells.

Methods

Human prostate cancer DU145 cells were treated with different concentrations of fish oil, omega-3 PUFA (DHA, and Eicosapentaenoic acid, EPA), or omega-6 PUFA (Arachidonic acid, AA). Cell viability and apoptosis were evaluated by MTT assay and Hoechst staining. Pathway-focused gene expression profiling of DU145 cells was analyzed with the RT² Profile PCR Array System. The results were verified by real time quantitative polymerase chain reaction (RT-qPCR).

Results

AA exposure showed no obvious effect on viability of DU145 cells. However, exposure with fish oil, EPA, or DHA for 24 h significantly affected cell viability. The growth inhibition of DHA was more pronounced than that of EPA and showed a time-dependent increase. DHA exposure caused typical apoptotic characteristics. Ten genes were more expressed, while 5 genes were less expressed following DHA exposure. RT-qPCR confirmed the time dependent effect of DHA on the expression of these differentially expressed genes. KEGG pathway analysis showed that DHA may induce the apoptosis of cancer cells preferentially through mediating P53, MAPK, TNF, PI3K/AKT, and NF-κB signaling pathways.

Conclusion

Our study demonstrated the beneficial action of DHA on human prostate carcinoma cell line DU145. The pro-apoptotic effect of DHA on DU145 cells may involve mediation various pathways, especially P53, MAPK, TNF, PI3K/AKT, and NF-κB signaling pathways. Molecular mechanisms of DHA on apoptosis of cancer cells still need to be further clarified.

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-017-0442-5) contains supplementary material, which is available to authorized users.

Fish-Derived Omega-3 Fatty Acids and Prostate Cancer: A Systematic Review

BACKGROUND

The use of natural health products in prostate cancer (PrCa) is high despite a lack of evidence with respect to safety and efficacy. Fish-derived omega-3 fatty acids possess anti-inflammatory effects and preclinical data suggest a protective effect on PrCa incidence and progression; however, human studies have yielded conflicting results.

METHODS

A search of OVID MEDLINE, Pre-MEDLINE, Embase, and the Allied and Complementary Medicine Database (AMED) was completed for human interventional or observational data assessing the safety and efficacy of fish-derived omega-3 fatty acids in the incidence and progression of PrCa.

RESULTS

Of 1776 citations screened, 54 publications reporting on 44 studies were included for review and analysis: 4 reports of 3 randomized controlled trials, 1 nonrandomized clinical trial, 20 reports of 14 cohort studies, 26 reports of 23 case-control studies, and 3 case-cohort studies. The interventional studies using fish oil supplements in patients with PrCa showed no impact on prostate-specific antigen levels; however, 2 studies showed a decrease in inflammatory or other cancer markers. A small number of mild adverse events were reported and interactions with other interventions were not assessed. Cohort and case-control studies assessing the relationship between dietary fish intake and the risk of PrCa were equivocal. Cohort studies assessing the risk of PrCa mortality suggested an association between higher intake of fish and decreased risk of prostate cancer-related death.

CONCLUSIONS

Current evidence is insufficient to suggest a relationship between fish-derived omega-3 fatty acid and risk of PrCa. An association between higher omega-3 intake and decreased PrCa mortality may be present but more research is needed. More intervention trials or observational studies with precisely measured exposure are needed to assess the impact of fish oil supplements and dietary fish-derived omega-3 fatty acid intake on safety, PrCa incidence, treatment, and progression.

Modulation of Ras/ERK and Phosphoinositide Signaling by Long-Chain n-3 PUFA in Breast Cancer and Their Potential Complementary Role in Combination with Targeted Drugs

A potential complementary role of the dietary long-chain n-3 polyunsaturated fatty acids (LCn-3 PUFA) in combination with innovative mono-targeted therapies has recently been proposed. These compounds are thought to act pleiotropically to prevent the development and progression of a variety of cancers, including breast cancer. We hereinafter critically analyze the reports investigating the ability of LCn-3 PUFA to modulate the Ras/ERK and the phosphoinositide survival signaling pathways often aberrantly activated in breast cancer and representing the main targets of innovative therapies. The in vitro or in vivo animal and human interventional studies published up to January 2017 investigating the effects of LCn-3 PUFA on these pathways in normal and cancerous breast cells or tissues were identified through a systematic search of literature in the PubMed database. We found that, in most cases, both the in vitro and in vivo studies demonstrated the ability of LCn-3 PUFA to inhibit the activation of these pro-survival pathways. Altogether, the analyzed results strongly suggest a potential role of LCn-3 PUFA as complementary agents in combination with mono-targeted therapies. Moreover, the results indicate the need for further in vitro and human interventional studies designed to unequivocally prove the potential adjuvant role of these fatty acids.

Effect of Dietary Omega-3 Fatty Acids on Tumor-Associated Macrophages and Prostate Cancer Progression

BACKGROUND

Preclinical and clinical studies suggest that a fish oil-based diet may play a role in delaying the progression of prostate cancer through a number of different mechanisms involving inflammatory pathways. Given the importance of tumor-associated macrophages (TAMs) in carcinogenesis, we hypothesized that a fish oil-based diet will inhibit TAM infiltration and delay the growth of prostate cancer.

METHODS

Androgen sensitive mouse prostate cancer (MycCaP) allograft tumors were grown in fully immunocompetent FVB mice fed a high- fat fish oil (omega-3) or corn oil (omega-6) diet. Gene expression of markers for immune cell populations, cytokines, chemokines, and signaling pathways were determined by real-time PCR and western blot in tumor tissue. Cell proliferation and apoptosis in vitro were measured by MTS assay and flow cytometry.

RESULTS

Tumor volumes were significantly smaller in mice in ω-3 versus the ω-6 group (P = 0.048). Gene expression of markers for M1 and M2 macrophages (F4/80, iNOS, ARG1), associated cytokines (IL-6, TNF alpha, IL-10), and the chemokine CCL-2 were also lower in the omega-3 group. Correlative in vitro studies were performed in M1 and M2 polarized macrophages and mirrored the in vivo findings. Dietary fish oil and in vitro omega-3 fatty acid administration reduced protein expression of transcription factors in the nuclear factor kappa B pathway leading to a significant decrease in gene expression of downstream targets (Bcl-2, BCL-XL, XIAP, survivin) in MycCap cells.

CONCLUSIONS

These findings underscore the potential of fish oil in modulating the clinical course of human prostate cancer through the immune system. Further preclinical and clinical studies are warranted evaluating fish oil-based therapies for inhibiting the recruitment and function of M1 and M2 tumor infiltrating macrophages. Prostate 76:1293-1302, 2016. © 2016 Wiley Periodicals, Inc.

The role of background diet on the effects of eicosapentaenoic acid and docosahexaenoic acid supplementation in healthy pre-menopausal women: a randomized, cross-over, controlled study

Background

The links between dietary fat intake, polyunsaturated fatty acid intake and breast cancer risk remain equivocal, with some studies pointing to improvements in risk upon omega-3 supplementation. However, the background diet is poorly controlled in most studies, potentially confounding this link. Therefore, this study examined the hypothesis that in order to see the benefits of omega-3 fatty acid supplementation, the background diet must be low in fat.

Methods

Of the 56 healthy, pre-menopausal women randomized to one of two experimental arms, consisting of a two-treatment, randomized, cross-over design, 41 completed the 10 month intervention. The two diet phases (habitual and low-fat) were separated by a washout phase, each lasting 3 menstrual cycles. During each diet phase, women were supplemented with 1.2 g eicosapentaenoic acid + docosahexaenoic acid per day.

Results

Red blood cell fatty acid composition indicated that more eicosapentaenoic acid and docosahexaenoic acid was incorporated in the low-fat diet than the habitual diet, though both diet phases resulted in significant increases in the omega-3 to omega-6 ratio. In the context of omega-3 supplementation in breast cancer risk reduction, we also measured fatty acid incorporation into nipple aspirate fluid. Similar changes to red blood cells were noted in nipple aspirate fluid, with higher incorporation of eicosapentaenoic acid in the low-fat diet phase.

Conclusions

These data suggest that the total level of dietary fat has some direct impact on fatty acid partitioning in addition to the recognized importance of fatty acid ratios, and supports the hypothesis that dietary fat intake must be considered a confounder in supplementation trials. Additionally, we demonstrate that n3 supplementation both reaches and imparts improvements in lipid content and n3:n6 at the target breast tissue.

Trial registration

Trial was been retrospectively registered at clinicaltrials.gov (RegNCT02816125).

Effects of ω-3 Fatty Acids and Catechins on Fatty Acid Synthase in the Prostate: A Randomized Controlled Trial

Animal and human studies suggest fish oil and green tea may have protective effect on prostate cancer. Fatty acid synthase (FAS) has been hypothesized to be linked to chemoprotective effects of both compounds. This study evaluated the independent and joint effects of fish oil (FO) and green tea supplement (epigallocatechin-3-gallate, EGCG) on FAS and Ki-67 levels in prostate tissue. Through a double-blinded, randomized controlled trial with 2 × 2 factorial design, 89 men scheduled for repeat prostate biopsy following an initial negative prostate biopsy were randomized into either FO alone (1.9 g DHA + EPA/day), EGCG alone (600 mg/day), a combination of FO and EGCG, or placebo. We used linear mixed-effects models to test the differences of prostate tissue FAS and Ki-67 by immunohistochemistry between pre- and post-intervention within each group, as well as between treatment groups. Results did not show significant difference among treatment groups in pre-to-post-intervention changes of FAS (P = 0.69) or Ki-67 (P = 0.26). Comparing placebo group with any of the treatment groups, we did not find significant difference in FAS or Ki-67 changes (all P > 0.05). Results indicate FO or EGCG supplementation for a short duration may not be sufficient to produce biologically meaningful changes in FAS or Ki-67 levels in prostate tissue.

A diagnosis of prostate cancer and pursuit of active surveillance is not followed by weight loss: potential for a teachable moment

BACKGROUND

Obesity is a risk factor for incident prostate cancer (PC) as well as risk of disease progression and mortality. We hypothesized that men diagnosed with lower-risk PC and who elected active surveillance (AS) for their cancer management would likely initiate lifestyle changes that lead to weight loss.

METHODS

Patients were enrolled in the Prostate Active Surveillance Study (PASS), a multicenter prospective biomarker discovery and validation study of men who have chosen AS for their PC. Data from 442 men diagnosed with PC within 1 year of study entry who completed a standard of care 12-month follow-up visit were analyzed. We examined the change in weight and body mass index (BMI) over the first year of study participation.

RESULTS

After 1 year on AS, 7.5% (33/442) of patients had lost 5% or more of their on-study weight. The proportion of men who lost 5% or more weight was similar across categories of baseline BMI: normal/underweight (8%), overweight (6%) and obese (10%, χ² test P=0.44). The results were similar for patients enrolled in the study 1 year or 6 months after diagnosis. By contrast, after 1 year, 7.7% (34/442) of patients had gained >5% of their weight.

CONCLUSIONS

Only 7.5% of men with low-risk PC enrolled in AS lost a modest (⩾5%) amount of weight after diagnosis. Given that obesity is related to PC progression and mortality, targeted lifestyle interventions may be effective at this 'teachable moment', as men begin AS for low-risk PC.

Prostate Cancer Associated Lipid Signatures in Serum Studied by ESI-Tandem Mass Spectrometryas Potential New Biomarkers

Prostate cancer (PCa) is one amongst the most common cancersin western men. Incidence rate ofPCa is on the rise worldwide. The present study deals with theserum lipidome profiling of patients diagnosed with PCa to identify potential new biomarkers. We employed ESI-MS/MS and GC-MS for identification of significantly altered lipids in cancer patient’s serum compared to controls. Lipidomic data revealed 24 lipids are significantly altered in cancer patinet’s serum (n = 18) compared to normal (n = 18) with no history of PCa. By using hierarchical clustering and principal component analysis (PCA) we could clearly separate cancer patients from control group. Correlation and partition analysis along with Formal Concept Analysis (FCA) have identified that PC (39:6) and FA (22:3) could classify samples with higher certainty. Both the lipids, PC (39:6) and FA (22:3) could influence the cataloging of patients with 100% sensitivity (all 18 control samples are classified correctly) and 77.7% specificity (of 18 tumor samples 4 samples are misclassified) with p-value of 1.612×10⁻⁶ in Fischer’s exact test. Further, we performed GC-MS to denote fatty acids altered in PCa patients and found that alpha-linolenic acid (ALA) levels are altered in PCa. We also performed an in vitro proliferation assay to determine the effect of ALA in survival of classical human PCa cell lines LNCaP and PC3. We hereby report that the altered lipids PC (39:6) and FA (22:3) offer a new set of biomarkers in addition to the existing diagnostic tests that could significantly improve sensitivity and specificity in PCa diagnosis.

A systematic review of dietary, nutritional, and physical activity interventions for the prevention of prostate cancer progression and mortality

PURPOSE

Given the long-term, although potentially fatal, nature of prostate cancer, there is increasing observational evidence for the reduction in disease progression and mortality through changes in lifestyle factors.

METHODS

We systematically reviewed dietary, nutritional, and physical activity randomized interventions aimed at modifying prostate cancer progression and disease-specific mortality, including a detailed assessment of risk of bias and methodological quality.

RESULTS

Forty-four randomized controlled trials of lifestyle interventions, with prostate cancer progression or mortality outcomes, were identified. Substantial heterogeneity of the data prevented a meta-analysis. The included trials involved 3,418 prostate cancer patients, median 64 men per trial, from 13 countries. A trial of a nutritional supplement of pomegranate seed, green tea, broccoli, and turmeric; a trial comparing flaxseed, low-fat diet, flaxseed, and low-fat diet versus usual diet; and a trial supplementing soy, lycopene, selenium, and coenzyme Q10, all demonstrated beneficial effects. These trials were also assessed as having low risk of bias and high methodological quality (as were seven other trials with no evidence of benefit). The remaining trials were either underpowered, at high or unclear risk of bias, inadequately reported, of short duration or measured surrogate outcomes of unproven relationship to mortality or disease progression, which precluded any benefits reported being reliable.

CONCLUSION

Large, well-designed randomized trials with clinical endpoints are recommended for lifestyle modification interventions.

n-3 Polyunsaturated Fatty Acids and their Role in Cancer Chemoprevention

Polyunsaturated fatty acids (PUFAs), including omega-3 (n-3) and omega-6 (n-6) PUFAs, are essential for human health. Recent research shows n-3 PUFAs and their mediators can inhibit inflammation, angiogenesis and cancer via multiple mechanisms, including reduced release of n-6 fatty acid arachidonic acid from cell membranes, inhibition of enzymatic activities, and direct competition with arachidonic acid for enzymatic conversions. In this review, we discuss inflammation-related cancer, anti-inflammatory effects of n-3 PUFA lipid mediators, antineoplastic activities of n-3 PUFA in vitro and in vivo, and present an update on recent human trials.

Nutrition, dietary interventions and prostate cancer: the latest evidence

Prostate cancer (PCa) remains a leading cause of mortality in US men and the prevalence continues to rise world-wide especially in countries where men consume a 'Western-style' diet. Epidemiologic, preclinical and clinical studies suggest a potential role for dietary intake on the incidence and progression of PCa. 'This minireview provides an overview of recent published literature with regard to nutrients, dietary factors, dietary patterns and PCa incidence and progression. Low carbohydrates intake, soy protein, omega-3 (w-3) fat, green teas, tomatoes and tomato products and zyflamend showed promise in reducing PCa risk or progression. A higher saturated 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. Despite the inconsistent and inconclusive findings, the potential for a role of dietary intake for the prevention and treatment of PCa is promising. The combination of all the beneficial factors for PCa risk reduction in a healthy dietary pattern may be the best dietary advice. This pattern includes rich fruits and vegetables, reduced refined carbohydrates, total and saturated fats, and reduced cooked meats. Further carefully designed prospective trials are warranted.

Disparate results between proliferation rates of surgically excised prostate tumors and an in vitro bioassay using sera from a positive randomized controlled trial

In vitro bioassay has been used extensively to test the effects of culturing cancer cells in sera from humans participating in dietary interventions, i.e, studies of modified intake of nutrients for the purpose of reducing cancer risk or progression. It has been hypothesized that cell proliferation rates determined by the in vitro bioassay indicate whether modification of dietary intake could decrease cancer cell growth in vivo. It has been suggested, however, that the in vitro bioassay may not correlate with tumor cell proliferation rates in prostate cancer. We investigated the concordance of cell proliferation rates from surgically excised prostate tumor tissue with the in vitro bioassay using sera from matched patients. We used samples from an earlier randomized clinical trial that showed that supplementation with flaxseed significantly inhibited prostate cancer cell proliferation rates in vivo as indicated by Ki67 staining in tumor specimens. Proliferation rates of LNCaP, DU145 and PC3 cell lines cultured in 10% human sera from participants in the flaxseed trial were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Spearman's Rho correlation coefficients (ρ) indicated no association between Ki67 staining in prostate tumors and the in vitro bioassay for the three cell lines. These disparate findings suggest that the in vitro bioassay may not provide an accurate assessment of the environment in vivo.

The use of dietary supplements to alleviate androgen deprivation therapy side effects during prostate cancer treatment

Prostate cancer (PCa), the most commonly diagnosed cancer and second leading cause of male cancer death in Western societies, is typically androgen-dependent, a characteristic that underlies the rationale of androgen deprivation therapy (ADT). Approximately 90% of patients initially respond to ADT strategies, however many experience side effects including hot flashes, cardiotoxicity, metabolic and musculoskeletal alterations. This review summarizes pre-clinical and clinical studies investigating the ability of dietary supplements to alleviate adverse effects arising from ADT. In particular, we focus on herbal compounds, phytoestrogens, selenium (Se), fatty acids (FA), calcium, and Vitamins D and E. Indeed, there is some evidence that calcium and Vitamin D can prevent the development of osteoporosis during ADT. On the other hand, caution should be taken with the antioxidants Se and Vitamin E until the basis underlying their respective association with type 2 diabetes mellitus and PCa tumor development has been clarified. However, many other promising supplements have not yet been subjected large-scale clinical trials making it difficult to assess their efficacy. Given the demographic trend of increased PCa diagnoses and dependence on ADT as a major therapeutic strategy, further studies are required to objectively evaluate these supplements as adjuvant for PCa patients receiving ADT.

ω-3 fatty acid differentially modulated serum levels of IGF1 and IGFBP3 in men with CVD: a randomized, double-blind placebo-controlled study

OBJECTIVE

Studies have reported elevated serum insulin-like growth factor (IGF)-1 levels followed by ω-3 supplementation in various groups. Considering decreased level of IGF1 in patients with cardiovascular disease (CVD) and protective effects of IGF1 against CVD progression and myocardial infarctions mortality, this study was performed with the aim of determining effects of ω-3 supplementation on serum levels and gene expression of IGF1 and IGF binding protein-3 (IGFBP3) in men with CVD.

METHODS

Sixty-two middle-aged (55.9 ± 6.5 y) non-obese men with CVD followed the study protocol in two groups of ω-3 (n = 31) or placebo (n = 31) supplementation. Participants took ω-3 supplement or placebo (edible paraffin) for 8 wk and were asked not to change their diet or physical activity plan. Anthropometric and lipid profile characteristics, serum IGF1, serum IGFBP3 and also IGF1 and IGFBP3 gene expression in peripheral blood mononuclear cells (PBMCs) were measured in all participants before and after the intervention. Statistical analyses were performed using SPSS software.

RESULTS

There were no significant differences between the two study groups in age and body mass index at baseline. The groups also had no difference in baseline serum low-density lipoprotein, high-density lipoprotein, very low-density lipoprotein, triacylglycerols, and IGF1. Compared with placebo, ω-3 supplementation increased serum IGF1 levels (P = 0.01), and decreased serum level of IGFBP3 (P = 0.02). There was a trending toward an increase in IGF1 expression and nonsignificant decrease in IGFBP3 expression.

CONCLUSIONS

ω-3 supplementation in patients with CVD increases serum IGF1 levels and decreases serum IGFBP3. Further research is warranted to investigate the underlying mechanisms.

Prostatic and dietary omega-3 fatty acids and prostate cancer progression during active surveillance

The association between omega-3 (ω-3) fatty acids and prostate cancer has been widely studied. However, little is known about the impact of prostate tissue fatty acid content on prostate cancer progression. We hypothesized that compared with the estimated dietary ω-3 fatty acids intake and the ω-3 fatty acids levels measured in red blood cells (RBC), the prostate tissue ω-3 fatty acid content is more strongly related to prostate cancer progression. We present the initial observations from baseline data of a phase II clinical trial conducted in a cohort of 48 untreated men affected with low-risk prostate cancer, managed under active surveillance. These men underwent a first repeat biopsy session within 6 months after the initial diagnosis of low-risk prostate cancer, at which time 29% of the men had progressed from a Gleason score of 6 to a Gleason score of 7. At the first repeat biopsy session, fatty acid levels were assessed with a food-frequency questionnaire, and determined in the RBC and in the prostate tissue biopsy. We found that eicosapentaenoic acid (EPA) was associated with a reduced risk of prostate cancer progression when measured directly in the prostate tissue. Thus, this initial interim study analysis suggests that prostate tissue ω-3 fatty acids, especially EPA, may be protective against prostate cancer progression in men with low-risk prostate cancer.

What should we tell prostate cancer patients about (secondary) prevention?

PURPOSE OF REVIEW

To briefly summarize the epidemiologic findings of selected lifestyle factors for prostate cancer progression, metastasis, or death, with a focus on behaviors after diagnosis where possible. We conclude by providing guidance on the lifestyle practices that physicians may wish to prioritize for discussion with their patients.

RECENT FINDINGS

Growing, but still limited, evidence suggests that lifestyle factors after prostate cancer diagnosis may impact prostate-cancer-specific and overall morality. In particular, smoking and obesity may increase the risk of disease progression and mortality, whereas engaging in vigorous physical activity or brisk walking and consuming a diet rich in vegetables (particularly tomato sauce and cruciferous) and vegetable fats may lower the risk.

SUMMARY

Patients should be counseled not to use tobacco products; to engage in daily physical activity; to minimize sedentary behavior; to consume plenty of healthy fats (i.e. fish, nuts, vegetable oils, soybeans, avocados, and flaxseed) and vegetables; to focus on getting nutrients from foods rather than supplements; and to limit refined grains, sugars, processed meat, and high-fat dairy.

Effect of a low-fat fish oil diet on proinflammatory eicosanoids and cell-cycle progression score in men undergoing radical prostatectomy

We previously reported that a 4- to 6-week low-fat fish oil (LFFO) diet did not affect serum insulin-like growth factor (IGF)-1 levels (primary outcome) but resulted in lower omega-6 to omega-3 fatty acid ratios in prostate tissue and lower prostate cancer proliferation (Ki67) as compared with a Western diet. In this post hoc analysis, the effect of the LFFO intervention on serum pro-inflammatory eicosanoids, leukotriene B4 (LTB4) and 15-S-hydroxyeicosatetraenoic acid [15(S)-HETE], and the cell-cycle progression (CCP) score were investigated. Serum fatty acids and eicosanoids were measured by gas chromatography and ELISA. CCP score was determined by quantitative real-time reverse transcriptase PCR (RT-PCR). Associations between serum eicosanoids, Ki67, and CCP score were evaluated using partial correlation analyses. BLT1 (LTB4 receptor) expression was determined in prostate cancer cell lines and prostatectomy specimens. Serum omega-6 fatty acids and 15(S)-HETE levels were significantly reduced, and serum omega-3 levels were increased in the LFFO group relative to the Western diet group, whereas there was no change in LTB4 levels. The CCP score was significantly lower in the LFFO compared with the Western diet group. The 15(S)-HETE change correlated with tissue Ki67 (R = 0.48; P < 0.01) but not with CCP score. The LTB4 change correlated with the CCP score (r = 0.4; P = 0.02) but not with Ki67. The LTB4 receptor BLT1 was detected in prostate cancer cell lines and human prostate cancer specimens. In conclusion, an LFFO diet resulted in decreased 15(S)-HETE levels and lower CCP score relative to a Western diet. Further studies are warranted to determine whether the LFFO diet antiproliferative effects are mediated through the LTB4/BLT1 and 15(S)-HETE pathways.

Current evidence linking polyunsaturated Fatty acids with cancer risk and progression

There is increasing evidence that polyunsaturated fatty acids (PUFAs) play a role in cancer risk and progression. The n-3 family of PUFAs includes alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) while the n-6 family includes linolenic acid (LA) and arachidonic acid (AA). EPA and DHA are precursors for anti-inflammatory lipid mediators while AA is a precursor for pro-inflammatory lipid mediators. Collectively, PUFAs play crucial roles in maintaining cellular homeostasis, and perturbations in dietary intake or PUFA metabolism could result in cellular dysfunction and contribute to cancer risk and progression. Epidemiologic studies provide an inconsistent picture of the associations between dietary PUFAs and cancer. This discrepancy may reflect the difficulties in collecting accurate dietary data; however, it also may reflect genetic variation in PUFA metabolism which has been shown to modify physiological levels of PUFAs and cancer risk. Also, host-specific mutations as a result of cellular transformation could modify metabolism of PUFAs in the target-tissue. Clinical trials have shown that supplementation with PUFAs or foods high in PUFAs can affect markers of inflammation, immune function, tumor biology, and prognosis. Pre-clinical investigations have begun to elucidate how PUFAs may mediate cell proliferation, apoptosis and angiogenesis, and the signaling pathways involved in these processes. The purpose of this review is to summarize the current evidence linking PUFAs and their metabolites with cancer and the molecular mechanisms that underlie this association. Identifying the molecular mechanism(s) through which PUFAs affect cancer risk and progression will provide an opportunity to pursue focused dietary interventions that could translate into the development of personalized diets for cancer control.

A study of caloric restriction versus standard diet in overweight men with newly diagnosed prostate cancer: a randomized controlled trial

INTRODUCTION

Obese men have an increased risk of prostate cancer (PCa)-specific mortality. Potential mechanisms include insulin and related proteins. We investigate whether a short-term caloric restriction diet in overweight/obese men with newly diagnosed PCa can lead to measurable changes in patient anthropometrics and insulin-related proteins.

METHODS

Overweight and obese PCa patients choosing active surveillance or radical prostatectomy were randomized to a 6-week, caloric-restricted diet or to continue their current diet. Changes from baseline to end of study in anthropometrics, dietary constituents and serum proteins (insulin, c-peptide, IGF-1, adiponectin, IGF-BP3) were compared between the intervention and control groups using a Generalized Estimating Equation model.

RESULTS

Nineteen patients were randomized to the intervention (N = 10) or control (N = 9) group. Men in the intervention group had a 1.7% (3.7 lbs) mean decline in weight versus 1.0% (2.0 lbs) in controls (P < 0.05), and a reduced intake of calories, total and saturated fat, protein and starch (all P < 0.1 compared to controls). There was a significant difference (P = 0.002) in mean serum IGFBP-3 between the intervention (+2.8%) and control group (-6.9%). Other biomarkers changed with the diet intervention to a degree similar to previous weight loss studies but were not statistically significant compared with controls.

CONCLUSION

In this small pilot study, a 6-week caloric restricted diet in men with newly diagnosed PCa produced changes in weight, diet and serum proteins possibly related to prognosis. These results support larger-scale trials testing longer-term weight loss effects on potential PCa progression biomarkers.

Fish oil slows prostate cancer xenograft growth relative to other dietary fats and is associated with decreased mitochondrial and insulin pathway gene expression

Background

Previous mouse studies suggest that decreasing dietary fat content can slow prostate cancer (PCa) growth. To our knowledge, no study has yet compared the effect of multiple different fats on PCa progression. We sought to systematically compare the effect of fish oil, olive oil, corn oil, and animal fat on PCa progression.

Methods

A total of 96 male SCID mice were injected with LAPC-4 human PCa cells. Two weeks following injection, mice were randomized to a fish oil, olive oil, corn oil, or animal fat-based Western diet (35% kcals from fat). Animals were euthanized when tumors reached 1,000mm³. Serum was collected at sacrifice and assayed for PSA, insulin, IGF-1, IGFBP-3, and PGE-2 levels. Tumors were also assayed for PGE-2 and COX-2 levels and global gene expression analyzed using Affymetrix microarrays.

Results

Mice weights and tumor volumes were equivalent across groups at randomization. Overall, fish oil consumption was associated with improved survival, relative to other dietary groups (p=0.014). On gene expression analyses, the fish oil group had decreased signal in pathways related to mitochondrial physiology and insulin synthesis/secretion.

Conclusions

In this xenograft model, we found that consuming a diet in which fish oil was the only fat source slowed tumor growth and improved survival, compared to mice consuming diets composed of olive oil, corn oil, or animal fat. While prior studies showed that the amount of fat is important for PCa growth, the current study suggests that type of dietary fat consumed may also be important.