Modulation of Breast Cancer Risk Biomarkers by High-Dose Omega-3 Fatty Acids: Phase II Pilot Study in Postmenopausal Women

Targeting EGFR in Combination with Nutritional Supplements on Antitumor Efficacy in a Lung Cancer Mouse Model

Selenium (Se) and fish oil (FO) exert anti-epidermal growth factor receptor (EGFR) action on tumors. This study aimed to compare the anti-cancer efficacy of EGFR inhibitors (gefitinib and erlotinib) alone and in combination with nutritional supplements of Se/FO in treating lung cancer. Lewis LLC1 tumor-bearing mice were treated with a vehicle or Se/FO, gefitinib or gefitinib plus Se/FO, and erlotinib or erlotinib plus Se/FO. The tumors were assessed for mRNA and protein expressions of relevant signaling molecules. Untreated tumor-bearing mice had the lowest body weight and highest tumor weight and volume of all the mice. Mice receiving the combination treatment with Se/FO and gefitinib or erlotinib had a lower tumor volume and weight and fewer metastases than did those treated with gefitinib or erlotinib alone. The combination treatment exhibited greater alterations in receptor signaling molecules (lower EGFR/TGF-β/TβR/AXL/Wnt3a/Wnt5a/FZD7/β-catenin; higher GSK-3β) and immune checkpoint molecules (lower PD-1/PD-L1/CD80/CTLA-4/IL-6; higher NKp46/CD16/CD28/IL-2). These mouse tumors also had lower angiogenesis, cancer stemness, epithelial to mesenchymal transitions, metastases, and proliferation of Ki-67, as well as higher cell cycle arrest and apoptosis. These preliminary results showed the Se/FO treatment enhanced the therapeutic efficacies of gefitinib and erlotinib via modulating multiple signaling pathways in an LLC1-bearing mouse model.

Change in Blood and Benign Breast Biomarkers in Women Undergoing a Weight-Loss Intervention Randomized to High-Dose ω-3 Fatty Acids versus Placebo

The inflammation-resolving and insulin-sensitizing properties of eicosapentaenoic (EPA) and docosahexaenoic (DHA) fatty acids have potential to augment effects of weight loss on breast cancer risk. In a feasibility study, 46 peri/postmenopausal women at increased risk for breast cancer with a body mass index (BMI) of 28 kg/m² or greater were randomized to 3.25 g/day combined EPA and DHA (ω-3-FA) or placebo concomitantly with initiation of a weight-loss intervention. Forty-five women started the intervention. Study discontinuation for women randomized to ω-3-FA and initiating the weight-loss intervention was 9% at 6 months and thus satisfied our main endpoint, which was feasibility. Between baseline and 6 months significant change (P < 0.05) was observed in 12 of 25 serum metabolic markers associated with breast cancer risk for women randomized to ω-3-FA, but only four for those randomized to placebo. Weight loss (median of 10% for trial initiators and 12% for the 42 completing 6 months) had a significant impact on biomarker modulation. Median loss was similar for placebo (-11%) and ω-3-FA (-13%). No significant change between ω-3-FA and placebo was observed for individual biomarkers, likely due to sample size and effect of weight loss. Women randomized to ω-3-FA exhibiting more than 10% weight loss at 6 months showed greatest biomarker improvement including 6- and 12-month serum adiponectin, insulin, omentin, and C-reactive protein (CRP), and 12-month tissue adiponectin. Given the importance of a favorable adipokine profile in countering the prooncogenic effects of obesity, further evaluation of high-dose ω-3-FA during a weight-loss intervention in obese high-risk women should be considered. PREVENTION RELEVANCE: This study examines biomarkers of response that may be modulated by omega-3 fatty acids when combined with a weight-loss intervention. While focused on obese, postmenopausal women at high risk for development of breast cancer, the findings are applicable to other cancers studied in clinical prevention trials.

Polyunsaturated Fatty Acids Mediated Regulation of Membrane Biochemistry and Tumor Cell Membrane Integrity

Particular dramatic macromolecule proteins are responsible for various cellular events in our body system. Lipids have recently recognized a lot more attention of scientists for understanding the relationship between lipid and cellular function and human health However, a biological membrane is formed with a lipid bilayer, which is called a P-L-P design. Our body system is balanced through various communicative signaling pathways derived from biological membrane proteins and lipids. In the case of any fatal disease such as cancer, the biological membrane compositions are altered. To repair the biological membrane composition and prevent cancer, dietary fatty acids, such as omega-3 polyunsaturated fatty acids, are essential in human health but are not directly synthesized in our body system. In this review, we will discuss the alteration of the biological membrane composition in breast cancer. We will highlight the role of dietary fatty acids in altering cellular composition in the P-L-P bilayer. We will also address the importance of omega-3 polyunsaturated fatty acids to regulate the membrane fluidity of cancer cells.

The Role of PPARγ Ligands in Breast Cancer: From Basic Research to Clinical Studies

Peroxisome proliferator-activated receptor gamma (PPARγ), belonging to the nuclear receptor superfamily, is a ligand-dependent transcription factor involved in a variety of pathophysiological conditions such as inflammation, metabolic disorders, cardiovascular disease, and cancers. In this latter context, PPARγ is expressed in many tumors including breast cancer, and its function upon binding of ligands has been linked to the tumor development, progression, and metastasis. Over the last decade, much research has focused on the potential of natural agonists for PPARγ including fatty acids and prostanoids that act as weak ligands compared to the strong and synthetic PPARγ agonists such as thiazolidinedione drugs. Both natural and synthetic compounds have been implicated in the negative regulation of breast cancer growth and progression. The aim of the present review is to summarize the role of PPARγ activation in breast cancer focusing on the underlying cellular and molecular mechanisms involved in the regulation of cell proliferation, cell cycle, and cell death, in the modulation of motility and invasion as well as in the cross-talk with other different signaling pathways. Besides, we also provide an overview of the in vivo breast cancer models and clinical studies. The therapeutic effects of natural and synthetic PPARγ ligands, as antineoplastic agents, represent a fascinating and clinically a potential translatable area of research with regards to the battle against cancer.

Serum Phospholipid Fatty Acids and Mammographic Density in Premenopausal Women

BACKGROUND

The role of fatty acids (FAs) on mammographic density (MD) is unclear, and available studies are based on self-reported dietary intake.

OBJECTIVES

This study assessed the association between specific serum phospholipid fatty acids (PLFAs) and MD in premenopausal women.

METHODS

The cross-sectional study DDM-Madrid recruited 1392 Spanish premenopausal women, aged 39-50 y, who attended a screening in a breast radiodiagnosis unit of Madrid City Council. Women completed lifestyle questionnaires and FFQs. Percentage MD was estimated using a validated computer tool (DM-Scan), and serum PLFA percentages were measured by GC-MS. Multivariable linear regression models were used to quantify the association of FA tertiles with MD. Models were adjusted for age, education, BMI, waist circumference, parity, oral contraceptive use, previous breast biopsies, and energy intake, and they were corrected for multiple testing.

RESULTS

Women in the third tertile of SFAs showed significantly higher MD compared with those in the first tertile (βT3vsT1 = 7.53; 95% CI: 5.44, 9.61). Elevated relative concentrations of palmitoleic (βT3vsT1 = 3.12; 95% CI: 0.99, 5.25) and gondoic (βT3vsT1 = 2.67; 95% CI: 0.57, 4.77) MUFAs, as well as high relative concentrations of palmitelaidic (βT3vsT1 = 5.22; 95% CI: 3.15, 7.29) and elaidic (βT3vsT1 = 2.69; 95% CI: 0.59, 4.79) trans FAs, were also associated with higher MD. On the contrary, women with elevated relative concentrations of n-6 (ω-6) linoleic (βT3vsT1 = -5.49; 95% CI; -7.62, -3.35) and arachidonic (βT3vsT1 = -4.68; 95% CI: -6.79, -2.58) PUFAs showed lower MD. Regarding desaturation indices, an elevated palmitoleic to palmitic ratio and a low ratio of oleic to steric and arachidonic to dihomo-γ-linolenic acids were associated with higher MD.

CONCLUSIONS

Spanish premenopausal women with high relative concentrations of most SFAs and some MUFAs and trans FAs showed an increased MD, whereas those with high relative concentrations of some n-6 PUFAs presented lower density. These results, which should be confirmed in further studies, underscore the importance of analyzing serum FAs individually.

The Effect of Omega-3 Polyunsaturated Fatty Acid Supplementations on anti-Tumor Drugs in Triple Negative Breast Cancer

Triple-negative breast cancer (TNBC) comprises about 10-20% of all diagnosed breast cancers. Increasing evidence shows that the omega-3 polyunsaturated fatty acids (ω-3PUFAs), docosahexaenoic acid and eicosapentaenoic acid, can influence the development, progression, and prognosis of TNBC In Vivo and In Vitro; however, clinical evidence supporting the effect of ω-3PUFAs on TNBC is lacking. Research has demonstrated that ω-3PUFAs can induce apoptosis in breast cancer cells by inhibiting the PI3K/AKT signal transduction pathway, and that ω-3PUFAs can improve the effectiveness of chemotherapy drugs. Using ω-3PUFA supplementation in addition to pharmacotherapy in the treatment of breast cancer may result in enhanced anti-tumor effects that will be particularly applicable to difficult to treat phenotypes such as TNBC. The aim of the current review was to summarize the evidence-base supporting the antitumor effects of omega-3 PUFAs in TNBC.

Customized Prevention Trials Could Resolve the Controversy of the Effects of Omega-3 Fatty Acids on Cancer

Literature data revealed that the benefits of consuming omega-3 fatty acid (n-3FA) supplements such as fish oil with the goal of reducing the incidence of chronic diseases such as cardiovascular disease and cancer remain controversial. The purpose of this commentary is to discuss factors that may account for the inconsistency of results across different studies. Critical review of the published data, including our own preclinical and clinical studies, strongly suggests that customized clinical prevention trials are needed to resolve the above-mentioned controversy. Specifically, in order to develop a personalized cancer prevention strategy, more attention should be given to multiple factors including the dose of the n-3FA, the specific placebo used as a comparator, duration of administration, type of intervention (primary vs secondary prevention trial), specific compound (DHA vs EPA vs their metabolites), the ratio of n-3FA:n-6FA and the target population tested (high vs average risk).

Selected Office Based Anticancer Treatment Strategies

Over the years, the treatment of patients with cancer has varied widely as much because of recent advancements in science and medicine as the philosophies that belie their use. This paper briefly describes many of the prevailing approaches in use today with an attempt to offer some perspective of how to apply these disparate methodologies so that they may be more effectively integrated, resulting in consistently better clinical responses.

Long-Chain Omega-3 Polyunsaturated Fatty Acids Modulate Mammary Gland Composition and Inflammation

Studies in rodents have shown that dietary modifications as mammary glands (MG) develop, regulates susceptibility to mammary tumor initiation. However, the effects of dietary PUFA composition on MGs in adult life, remains poorly understood. This study investigated morphological alterations and inflammatory microenvironments in the MGs of adult mice fed isocaloric and isolipidic liquid diets with varying compositions of omega (ω)-6 and long-chain (Lc)-ω3FA that were pair-fed. Despite similar consumption levels of the diets, mice fed the ω-3 diet had significantly lower body-weight gains, and abdominal-fat and mammary fat pad (MFP) weights. Fatty acid analysis showed significantly higher levels of Lc-ω-3FAs in the MFPs of mice on the ω-3 diet, while in the MFPs from the ω-6 group, Lc-ω-3FAs were undetectable. Our study revealed that MGs from ω-3 group had a significantly lower ductal end-point density, branching density, an absence of ductal sprouts, a thinner ductal stroma, fewer proliferating epithelial cells and a lower transcription levels of estrogen receptor 1 and amphiregulin. An analysis of the MFP and abdominal-fat showed significantly smaller adipocytes in the ω-3 group, which was accompanied by lower transcription levels of leptin, IGF1, and IGF1R. Further, MFPs from the ω-3 group had significantly decreased numbers and sizes of crown-like-structures (CLS), F4/80+ macrophages and decreased expression of proinflammatory mediators including Ptgs2, IL6, CCL2, TNFα, NFκB, and IFNγ. Together, these results support dietary Lc-ω-3FA regulation of MG structure and density and adipose tissue inflammation with the potential for dietary Lc-ω-3FA to decrease the risk of mammary gland tumor formation.

A Randomized Multicenter Phase II Study of Docosahexaenoic Acid in Patients with a History of Breast Cancer, Premalignant Lesions, or Benign Breast Disease

Obesity, a cause of subclinical inflammation, is a risk factor for the development of postmenopausal breast cancer and is associated with poorer cancer outcomes. Docosahexaenoic acid (DHA), an omega-3 fatty acid, possesses anti-inflammatory properties. We hypothesized that treatment with DHA would reduce the expression of proinflammatory genes and aromatase, the rate-limiting enzyme for estrogen biosynthesis, in benign breast tissue of overweight/obese women. A randomized, placebo-controlled, double-blind phase II study of DHA given for 12 weeks to overweight/obese women with a history of stage I-III breast cancer, DCIS/LCIS, Paget's disease, or proliferative benign breast disease was carried out. In this placebo controlled trial, the primary objective was to determine whether DHA (1,000 mg by mouth twice daily) reduced breast tissue levels of TNFα. Secondary objectives included evaluation of the effect of DHA on breast tissue levels of COX-2, IL1β, aromatase, white adipose tissue inflammation, and gene expression by RNA-seq. Red blood cell fatty acid levels were measured to assess compliance. From July 2013 to November 2015, 64 participants were randomized and treated on trial (32 women per arm). Increased levels of omega-3 fatty acids in red blood cells were detected following treatment with DHA (P < 0.001) but not placebo. Treatment with DHA did not alter levels of TNFα (P = 0.71), or other biomarkers including the transcriptome in breast samples. Treatment with DHA was overall well-tolerated. Although compliance was confirmed, we did not observe changes in the levels of prespecified biomarkers in the breast after treatment with DHA when compared with placebo. Cancer Prev Res; 11(4); 203-14. ©2018 AACRSee related editorial by Fabian and Kimler, p. 187.

The Conundrum of Omega-3 Fatty Acids in Cancer Prevention Studies: Which One? How Much? What Biomarkers?

Marine omega-3 fatty acids promote resolution of inflammation and have potential to reduce risk of obesity-related breast cancer. For prevention trials in obese women, inflammatory cytokines, aromatase, and measures of breast immune cell infiltration are logical, as are biomarkers of growth factor, adipokine, and estrogen signaling. Where best to look for marker change: in the circulation (easiest), in benign breast tissue (most relevant), or in visceral adipose (inflammation often most marked)? A null biomarker modulation trial may reflect limitations in design, source and dose of fatty acids, or biomarkers and should not lead to premature abandonment of marine omega-3 fatty acids for cancer prevention. Cancer Prev Res; 11(4); 187-90. ©2018 AACRSee related article by Gucalp et al., p. 203.

The potential contribution of dietary factors to breast cancer prevention

Breast cancer (BC), the leading cancer in women, is increasing in prevalence worldwide, concurrent with western metabolic epidemics, that is, obesity, metabolic syndrome, and diabetes, and shares major risk factors with these diseases. The corresponding potential for nutritional contributions toward BC prevention is reviewed and related to critical stages in the life cycle and their implications for carcinogenic and pathometabolic trajectories. BC initiation potentially involves diet-related pro-oxidative, inflammatory, and procarcinogenic processes, that interact through combined lipid/fatty acid peroxidation, estrogen metabolism, and related DNA-adduct/depurination/mutation formation. The pathometabolic trajectory is affected by high estrogen, insulin, and growth factor cascades and resultant accelerated proliferation/progression. Anthropometric risk factors - high birth weight, adult tallness, adiposity/BMI, and weight gain - are often reflective of these trends. A sex-based nutritional approach targets women's specific risk in western obesogenic environments, associated with increasing fatness, estrogen metabolism, n-6 : n-3 polyunsaturated fatty acid ratio, and n-6 polyunsaturated fatty acid conversion to proinflammatory/carcinogenic eicosanoids, and effects of timing of life events, for example, ages at menarche, full-term pregnancy, and menopause. Recent large-scale studies have confirmed the effectiveness of the evidence-based recommendations against BC risk, emphasizing low-energy density diets, highly nutritious plant-based regimes, physical activity, and body/abdominal adiposity management. Better understanding of dietary inter-relationships with BC, as applied to food intake, selection, combination, and processing/preparation, and recommended patterns, for example, Mediterranean, DASH, plant-based, low energy density, and low glycemic load, with high nutrient/phytonutrient density, would increase public motivation and authoritative support for early/timely prevention, optimally merging with other dietary/health goals, for lifelong BC prevention.

DHA increases adiponectin expression more effectively than EPA at relative low concentrations by regulating PPARγ and its phosphorylation at Ser273 in 3T3-L1 adipocytes

BACKGROUND

Enhancing circulating adiponectin is considered as a potential approach for the prevention and treatment of non-communicable diseases (NCDs). Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) were reported to increase adiponectin by previous studies using a mixture of them. However, their individual effects on adiponectin and the underlying mechanisms are still unclear. In the present study, we observed and compared the individual effect of DHA and EPA on adiponectin in 3T3-L1 adipocytes, and further tested whether DHA or EPA regulated adiponectin by peroxisome proliferator-activated receptor γ (PPARγ) and its phosphorylation at Ser273 to provide a plausible explanation for their distinct actions.

METHODS

Firstly, 3T3-L1 adipocytes were treated with different doses of DHA or EPA for 24 h. Secondly, 3T3-L1 adipocytes were treated with DHA or EPA in the presence or absence of GW9662. Thirdly, 3T3-L1 adipocytes were pretreated with DHA or EPA for 24 h, followed by being respectively co-incubated with tumor necrosis factor α (TNF-α) or roscovitine for another 2 h. Bovine serum albumin treatment served as the control. After treatments, cellular and secreted adiponectin, cellular PPARγ and its phosphorylation at Ser273 were determined.

RESULTS

Compared with the control, DHA increased cellular and secreted adiponectin at 50 and 100 μmol/L, while EPA increased them at 100 and 200 μmol/L. Adiponectin expressions in DHA treated groups were significantly higher than those in EPA treated groups at 50 and 100 μmol/L. Both DHA and EPA enhanced PPARγ expression, but DHA was more effective. GW9662 blocked DHA- and EPA-induced increases in PPARγ as well as adiponectin. Remarkably, an opposite regulation of PPARγ phosphorylation was detected after fatty acids treatment: DHA inhibited it but EPA stimulated it. TNF-α blocked DHA-induced decrease in PPARγ phosphorylation, which eventually led to a decrease in adiponectin. Roscovitine blocked EPA-induced increase in PPARγ phosphorylation, but the corresponding increase in adiponectin was non-significant.

CONCLUSION

DHA compared with EPA led to a greater increase in cellular and secreted adiponectin at relative low concentrations by increasing PPARγ expression and inhibiting its phosphorylation at Ser273. DHA may be more beneficial than EPA in reducing risks of NCDs.

Phytotherapy and Nutritional Supplements on Breast Cancer

Breast cancer is the most frequent type of nonskin malignancy among women worldwide. In general, conventional cancer treatment options (i.e., surgery, radiotherapy, chemotherapy, biological therapy, and hormone therapy) are not completely effective. Recurrence and other pathologic situations are still an issue in breast cancer patients due to side effects, toxicity of drugs in normal cells, and aggressive behaviour of the tumours. From this point of view, breast cancer therapy and adjuvant methods represent a promising and challenging field for researchers. In the last few years, the use of some types of complementary medicines by women with a history of breast cancer has significantly increased such as phytotherapeutic products and nutritional supplements. Despite this, the use of such approaches in oncologic processes may be problematic and patient's health risks can arise such as interference with the efficacy of standard cancer treatment. The present review gives an overview of the most usual phytotherapeutic products and nutritional supplements with application in breast cancer patients as adjuvant approach. Regardless of the contradictory results of scientific evidence, we demonstrated the need to perform additional investigation, mainly well-designed clinical trials in order to establish correlations and allow for further validated outcomes concerning the efficacy, safety, and clinical evidence-based recommendation of these products.

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.

Measurement of red blood cell eicosapentaenoic acid (EPA) levels in a randomised trial of EPA in patients with colorectal cancer liver metastases

We investigated red blood cell (RBC) PUFA profiles, and the predictive value of RBC EPA content for tumour EPA exposure and clinical outcomes, in the EMT study, a randomised trial of EPA in patients awaiting colorectal cancer (CRC) liver metastasis surgery (Cockbain et al., 2014) [8]. There was a significant increase in RBC EPA in the EPA group (n=43; median intervention 30 days; mean absolute 1.26[±0.14]% increase; P<0.001), but not in the placebo arm (n=45). EPA incorporation varied widely in EPA users and was not explained by treatment duration or compliance. There was little evidence of 'contamination' in the placebo group. The EPA level predicted tumour EPA content (r=0.36; P=0.03). Participants with post-treatment EPA≥1.22% (n=49) had improved OS compared with EPA <1.22% (n=29; HR 0.42[95%CI 0.16-0.95]). RBC EPA content should be evaluated as a biomarker of tumour exposure and clinical outcomes in future EPA trials in CRC patients.

Role of n-3 Polyunsaturated Fatty Acids and Exercise in Breast Cancer Prevention: Identifying Common Targets

Diet and exercise are recognized as important lifestyle factors that significantly influence breast cancer risk. In particular, dietary n-3 polyunsaturated fatty acids (PUFAs) have been shown to play an important role in breast cancer prevention. Growing evidence also demonstrates a role for exercise in cancer and chronic disease prevention. However, the potential synergistic effect of n-3 PUFA intake and exercise is yet to be determined. This review explores targets for breast cancer prevention that are common between n-3 PUFA intake and exercise and that may be important study outcomes for future research investigating the combined effect of n-3 PUFA intake and exercise. These lines of evidence highlight potential new avenues for research and strategies for breast cancer prevention.

Dietary Associations with a Breast Cancer Risk Biomarker Depend on Menopause Status

We investigated how timing influences the role of diet in breast cancer risk with a cross-sectional study of pre-malignant change in breast tissue. Women with an elevated risk of developing breast cancer (33 premenopausal and 32 postmenopausal) completed the National Cancer Institute's food frequency questionnaire and underwent random periareolar fine-needle aspiration for evaluation of cytologic atypia, an established risk biomarker. Fatty acid composition of breast adipose was measured in 32 (49%) subjects. We found that premenopausal and postmenopausal women had similar diets, but the associations between atypia and intake of total n-3 polyunsaturated fatty acids (PUFA) and soy differed by menopause status (both P interaction < 0.001). Total n-3 PUFA intake was inversely associated with atypia among premenopausal women (P < 0.0001), but not among postmenopausal women (P = 0.91); associations were similar for soy (P = 0.0003 and P = 0.48, respectively). This pattern of dietary interaction with menopause was mirrored in tissue fatty acids (P interaction < 0.05), wherein 1) higher levels of linolelaidic acid (an industrially-produced trans fat) and 2) lower levels of docosahexaenoic acid (the predominant long-chain n-3 PUFA) in breast adipose were associated with atypia in premenopausal (both P < 0.05) but not postmenopausal women (both P > 0.37). Dietary associations with breast cancer risk are stronger prior to menopause.

Reducing the burden of obesity-associated cancers with anti-inflammatory long-chain omega-3 polyunsaturated fatty acids

Today's world population has an unprecedented risk of dying from the consequences of being overweight and obese. Chronic diseases such as cardiovascular disease, type 2 diabetes, and cancer are often accelerated because of excessive adiposity. Various biological mechanisms are implicated in the obesity-cancer link, particularly local and systemic inflammation as well as altered growth factor signaling pathways. In order to combat obesity-induced inflammation and the resulting increases in cancer risk and progression, the identification of safe and effective mechanism-based interventions is imperative. Notably, long chain omega-3 polyunsaturated fatty acids (PUFAs) modulate the secretion of pro-inflammatory cytokines, prostaglandins and other inflammatory mediators, restore insulin sensitivity, and can prevent or delay tumorigenesis. Delineating the precise mechanisms by which omega-3 PUFAs suppress obesity-induced inflammation will help identify promising key mechanistic targets and intervention strategies to break the obesity-cancer link.

Modulation of Breast Cancer Risk Biomarkers by High-Dose Omega-3 Fatty Acids: Phase II Pilot Study in Premenopausal Women

Higher intakes of the omega-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) relative to the omega-6 arachidonic acid (AA) have been variably associated with reduced risk of premenopausal breast cancer. The purpose of this pilot trial was to assess feasibility and explore the effects of high-dose EPA and DHA on blood and benign breast tissue risk biomarkers before design of a placebo-controlled phase IIB trial. Premenopausal women with evidence of hyperplasia ± atypia by baseline random periareolar fine needle aspiration were given 1860 mg of EPA + 1500 mg of DHA ethyl esters daily for 6 months. Blood and benign breast tissue were sampled during the same menstrual cycle phase prestudy and a median of 3 weeks after last dose. Additional blood was obtained within 24 hours of last dose. Feasibility, which was predefined as 50% uptake, 85% retention, and 70% compliance, was demonstrated with 46% uptake, 94% completion, and 85% compliance. Cytologic atypia decreased from 77% to 38% (P = 0.002), and Ki-67 from a median of 2.1% to 1.0% (P = 0.021) with an increase in the ratio of EPA + DHA to AA in erythrocyte phospholipids but no change in blood hormones, adipokines, or cytokines. Exploratory breast proteomics assessment showed decreases in several proteins involved in hormone and cytokine signaling with mixed effects on those in the AKT/mTOR pathways. Further investigation of EPA plus DHA for breast cancer prevention in a placebo-controlled trial in premenopausal women is warranted.