Plasma phospholipids fatty acids, dietary fatty acids, and breast cancer risk

Diet Modulates the Gut Microbiome, Metabolism, and Mammary Gland Inflammation to Influence Breast Cancer Risk

Several studies indicate a strong link between obesity and the risk of breast cancer. Obesity decreases gut microbial biodiversity and modulates Bacteroidetes-to-Firmicutes phyla proportional abundance, suggesting that increased energy-harvesting capacity from indigestible dietary fibers and elevated lipopolysaccharide bioavailability may promote inflammation. To address the limited evidence linking diet-mediated changes in gut microbiota to breast cancer risk, we aimed to determine how diet affects the microbiome and breast cancer risk. For ten weeks, female 3-week-old BALB/c mice were fed six different diets (control, high-sugar, lard, coconut oil, lard + flaxseed oil, and lard + safflower oil). Fecal 16S sequencing was performed for each group. Diet shifted fecal microbiome populations and modulated mammary gland macrophage infiltration. Fecal-conditioned media shifted macrophage polarity and inflammation. In our DMBA-induced breast cancer model, diet differentially modulated tumor and mammary gland metabolism. We demonstrated how dietary patterns change metabolic outcomes and the gut microbiota, possibly contributing to breast tumor risk. Furthermore, we showed the influence of diet on metabolism, inflammation, and macrophage polarity. This study suggests that dietary-microbiome interactions are key mediators of breast cancer risk. Prevention Relevance: Our study demonstrates the impact of diet on breast cancer risk, focusing on the interplay between diet, the gut microbiome, and mammary gland inflammation.

Platelet and epithelial cell interations can be modeled in cell culture, and are not affected by dihomo-gamma-linolenic acid

Increasing evidence is implicating roles for platelets in the development and progression of ovarian cancer, a highly lethal disease that can arise from the fallopian tubes, and has no current method of early detection or prevention. Thrombosis is a major cause of mortality of ovarian cancer patients suggesting that the cancer alters platelet behavior. The objective of this study was to develop a cell culture model of the pathological interactions of human platelets and ovarian cancer cells, using normal FT epithelial cells as a healthy control, and to test effects of the anti-platelet dihomo-gamma-linolenic acid (DGLA) in the model. Both healthy and cancer cells caused platelet aggregation, however platelets only affected spheroid formation by cancer cells and had no effect on healthy cell spheroid formation. When naturally-formed spheroids of epithelial cells were exposed to platelets in transwell inserts that did not allow direct interactions of the two cell types, platelets caused increased size of the spheroids formed by cancer cells, but not healthy cells. When cancer cell spheroids formed using magnetic nanoshuttle technology were put in direct physical contact with platelets, the platelets caused spheroid condensation. In ovarian cancer cells, DGLA promoted epithelial-to-mesenchymal (EMT) transition at doses as low as 100 μM, and inhibited metabolic viability and induced apoptosis at doses ≥150 μM. DGLA doses ≤150 μM used to avoid direct DGLA effects on cancer cells, had no effect on the pathological interactions of platelets and ovarian cancer cells in our models. These results demonstrate that the pathological interactions of platelets with ovarian cancer cells can be modeled in cell culture, and that DGLA has no effect on these interactions, suggesting that targeting platelets is a rational approach for reducing cancer aggressiveness and thrombosis risk in ovarian cancer patients, however DGLA is not an appropriate candidate for this strategy.

ACSL4-Mediated Membrane Phospholipid Remodeling Induces Integrin β1 Activation to Facilitate Triple-Negative Breast Cancer Metastasis

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer and has a poor prognosis and a high propensity to metastasize. Lipid metabolism has emerged as a critical regulator of tumor progression and metastasis in other cancer types. Characterization of the lipid metabolic features of TNBC could provide important insights into the drivers of TNBC metastasis. Here, we showed that metastatic TNBC tumors harbor more unsaturated phospholipids, especially long-chain polyunsaturated fatty acids, at the sn-2 position of phosphatidylcholine and phosphatidylethanolamine compared with primary tumors. Metastatic TNBC tumors upregulated ACSL4, a long-chain polyunsaturated acyl-CoA synthetase that drives the preferential incorporation of polyunsaturated fatty acids into phospholipids, resulting in the alteration of membrane phospholipid composition and properties. Moreover, ACSL4-mediated phospholipid remodeling of the cell membrane induced lipid-raft localization and activation of integrin β1 in a CD47-dependent manner, which led to downstream focal adhesion kinase phosphorylation that promoted metastasis. Importantly, pharmacologic inhibition of ACSL4 suppressed tumor growth and metastasis and increased chemosensitivity in TNBC models in vivo. These findings indicate that ACSL4-mediated phospholipid remodeling enables TNBC metastasis and can be inhibited as a potential strategy to improve the efficacy of chemotherapy in TNBC.

SIGNIFICANCE

ACSL4 upregulation in triple-negative breast cancer alters cell membrane phospholipid composition to increase integrin β1 activation and drive metastasis, indicating that targeting ACSL4 could potentially block metastasis and improve patient outcomes.

Association between dietary intake of saturated fatty acid subgroups and breast cancer risk

The impact of dietary saturated fatty acids (SFAs) on breast cancer risk may vary depending on their carbon chain lengths, attributable to the discrepancy in their dietary sources and biological activities. The associations between SFA subgroups classified by chain length and breast cancer risk remain controversial. In this case-control study, we aimed to investigate the association between the dietary intake of SFA subgroups, classified by chain lengths, and odds of breast cancer in China. This study included 1661 cases of breast cancer (confirmed as primary and histologically) and 1674 frequency-matched controls. Face-to-face interviews were used to collect basic information, while dietary intake information was obtained by a food frequency questionnaire. The unconditional logistic regression model was used to calculate the odds ratios (ORs) and 95% confidence intervals (95% CIs). All SFA subgroups were inversely associated with odds of breast cancer. The adjusted ORs (95% CIs) were 0.78 (0.61-0.99) for medium-chain SFAs, 0.50 (0.31-0.83) for long even-chain SFAs, 0.69 (0.54-0.88) for long odd-chain, and 0.67 (0.48-0.95) for very long-chain SFAs, respectively. In the restricted cubic spline (RCS) models, a non-linear M-shaped association was observed between long odd-chain SFAs and odds of breast cancer (Pnon-linearity = 0.007). However, the associations of medium-chain SFAs, long even-chain SFAs, and very long-chain SFAs did not reach statistical significance (Pnon-linearity > 0.05). No significant interactions were observed between all these four subgroups of SFAs and menopausal status or BMI. Our findings emphasize the significance of elucidating the associations of dietary SFAs according to chain lengths, providing insights into the etiology as well as the potential benefits of SFA-rich food intake in reducing the risk of breast cancer. Further prospective cohort studies and intervention studies are warranted to confirm these findings and identify the underlying mechanisms of the association between dietary SFAs and breast cancer.

Erythrocyte membrane n-3 PUFA are inversely associated with breast cancer risk among Chinese women

The relationship between erythrocyte membrane n-3 PUFA and breast cancer risk is controversial. We aimed to examine the associations of erythrocyte membrane n-3 PUFA with odds of breast cancer among Chinese women by using a relatively large sample size. A case-control study was conducted including 853 newly diagnosed, histologically confirmed breast cancer cases and 892 frequency-matched controls (5-year interval). Erythrocyte membrane n-3 PUFA were measured by GC. Logistic regression and restricted cubic spline were used to quantify the association between erythrocyte membrane n-3 PUFA and odds of breast cancer. Erythrocyte membrane α-linolenic acid (ALA), docosapentaenoic acid (DPA) and total n-3 PUFA were inversely and non-linearly associated with odds of breast cancer. The OR values (95 % CI), comparing the highest with the lowest quartile (Q), were 0·57 (0·43, 0·76), 0·43 (0·32, 0·58) and 0·36 (0·27, 0·49) for ALA, DPA and total n-3 PUFA, respectively. Erythrocyte membrane EPA and DHA were linearly and inversely associated with odds of breast cancer ((EPA: ORQ4 v. Q1 (95 % CI) = 0·59 (0·45, 0·79); DHA: ORQ4 v. Q1 (95 % CI) = 0·50 (0·37, 0·67)). The inverse associations were observed between ALA and odds of breast cancer in postmenopausal women, and between DHA and oestrogen receptor+ breast cancer. This study showed that erythrocyte membrane total and individual n-3 PUFA were inversely associated with odds of breast cancer. Other factors, such as menopause and hormone receptor status, may warrant further investigation when examining the association between n-3 PUFA and odds of breast cancer.

The Involvement of Polyunsaturated Fatty Acids in Apoptosis Mechanisms and Their Implications in Cancer

Cancer is a significant global public health issue and, despite advancements in detection and treatment, the prognosis remains poor. Cancer is a complex disease characterized by various hallmarks, including dysregulation in apoptotic cell death pathways. Apoptosis is a programmed cell death process that efficiently eliminates damaged cells. Several studies have indicated the involvement of polyunsaturated fatty acids (PUFAs) in apoptosis, including omega-3 PUFAs such as alpha-linolenic acid, docosahexaenoic acid, and eicosapentaenoic acid. However, the role of omega-6 PUFAs, such as linoleic acid, gamma-linolenic acid, and arachidonic acid, in apoptosis is controversial, with some studies supporting their activation of apoptosis and others suggesting inhibition. These PUFAs are essential fatty acids, and Western populations today have a high consumption rate of omega-6 to omega-3 PUFAs. This review focuses on presenting the diverse molecular mechanisms evidence in both in vitro and in vivo models, to help clarify the controversial involvement of omega-3 and omega-6 PUFAs in apoptosis mechanisms in cancer.

Serum Saturated Fatty Acids including Very Long-Chain Saturated Fatty Acids and Colorectal Cancer Risk among Chinese Population

The association between circulating saturated fatty acids (SFAs) including very long-chain SFAs (VLCSFAs) and colorectal cancer (CRC) risk has not been clearly established. To investigate the association between serum SFAs and CRC risk in Chinese population, 680 CRC cases and 680 sex and age-matched (5-year interval) controls were recruited in our study. Serum levels of SFAs were detected by gas chromatography. Unconditional logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between serum SFAs and CRC risk. Results showed that total SFAs were positively associated with the risk of CRC (adjusted OR _{quartile 4 vs. 1} = 2.64, 95%CI: 1.47-4.74). However, VLCSFAs were inversely associated with CRC risk (adjusted OR _{quartile 4 vs. 1} = 0.51, 95%CI: 0.36-0.72). Specifically, lauric acid, myristic acid, palmitic acid, heptadecanoic acid, and arachidic acid were positively associated with CRC risk, while behenic acid and lignoceric acid were inversely associated with CRC risk. This study indicates that higher levels of total serum SFAs and lower levels of serum VLCSFAs were associated with an increased risk of CRC in Chinese population. To reduce the risk of CRC, we recommend reducing the intake of foods containing palmitic acid and heptadecanoic acid such as animal products and dairy products, and moderately increasing the intake of foods containing VLCSFAs such as peanuts and canola oil.

Circulating plasma phospholipid fatty acid levels and breast cancer risk in the Cancer Prevention Study-II Nutrition Cohort

Prospective studies that objectively measure circulating levels of fatty acids are needed to clarify their role in the etiology of breast cancer. Thirty-eight phospholipid fatty acids were measured using gas chromatograph in the plasma fraction of blood samples collected prospectively from 2718 postmenopausal women (905 breast cancer cases) enrolled in the Cancer Prevention Study II Nutrition Cohort. Associations of 28 fatty acids that passed quality control metrics (modeled as per 1-SD increase) with breast cancer risk were assessed using multiple variable conditional logistic regression models to compute odds ratios (OR) and 95% confidence intervals (CI). The false discovery rate (q value) was computed to account for multiple comparisons. Myristic acid levels were positively associated with breast cancer risk (OR, 1.17, 95% CI: 1.07-1.28; q value = 0.03). Borderline associations were also found for palmitoleic acid (OR, 1.14, 95% CI: 1.04-1.24) and desaturation index16 (OR, 1.10, 95% CI: 1.01-1.20) at nominal P values (<.03) (q values>0.05). These findings suggest that higher circulating levels of myristic acid, sourced from dietary intake of palm kernel oils along with increased de novo synthesis of fatty acids, may increase breast cancer risk. Additional studies are needed to investigate de novo synthesis of fatty acid in breast cancer tissues.

High-Fat Diet as a Risk Factor for Breast Cancer: A Meta-Analysis

High-fat diets have been identified as a major cause of obesity and a potential risk factor for breast cancer. Fat tissue, also known as adipose tissue, produces an excess of estrogen, which has been linked to an increased risk of breast cancer. Determining the impact of HFDs in the development and progression of breast cancer is essential, as it will enable us to identify the role of dietary modification in preventing and managing the disease. The impact of a high-fat diet (HFD) on the development of breast cancer in humans has yet to be fully explained, as very few human studies are available to effectively analyze the effect fatty food has on breast cancer development. This meta-analysis, therefore, seeks to determine the strength of association, if any, between HFD and an increased risk of breast cancer development. This research will help inform good eating habits, potentially reducing the disease's incidence and outcome. This meta-analysis examined eight (8) papers from various nations examining the effect of a high-fat diet as a risk factor for breast cancer development between 2010 and 2020. The study employed the multivariable-adjusted hazard ratio (H.R.), odds ratio (OR), or relative risk (R.R.) from the studies. Breast cancer cases were histologically and radiologically confirmed in the studies evaluated, and validated food frequency questionnaires were used to assess their dietary patterns. This metanalysis study found a substantial link between a high-fat diet and an increased risk of breast cancer, with statistically significant results (I² = 93.38%, p0.05). Changes in dietary fat consumption may thus help mitigate some of the unfavorable consequences of breast cancer and survival. Even if further research is needed to support this assertion, the findings are compelling enough to advocate for low-fat, healthy diets to avoid breast cancer.

The association between circulating docosahexaenoic acid and lung cancer: A Mendelian randomization study

BACKGROUND

Lung cancer is a malignant tumor with a high incidence, it is vital to identify modifiable and avoidable risk factors for primary prevention, which can significantly lower the risk of cancer by preventing exposure to hazards and altering risky behavior. Some observational studies suggest that an increase in docosahexaenoic acid (DHA) consumption can reduce lung cancer risk. However, interpretation of these observational findings is difficult due to residual confounding or reverse causality. To evaluate the link between DHA and lung cancer, we have undertaken this analysis to examine the causal association between DHA and the risk of lung cancer using a two-sample Mendelian randomization (MR) framework.

METHODS

We performed a two-sample MR analysis to evaluate the causal effect of plasma DHA levels on lung cancer risk. For the exposure data, we extracted genetic variants as instrumental variables (IVs) that are strongly associated with DHA from a large-scale genome-wide association study (GWAS). We obtained the corresponding effect estimates for IVs on the risk of lung cancer with 11,348 cases and 15,861 controls. Finally, we applied Mendelian randomization analysis to obtain preliminary MR results and performed sensitivity analyses to verify the robustness of our results.

RESULTS

According to the primary MR estimates and further sensitivity analyses, a higher serum DHA level was associated with a higher risk of lung cancer [OR = 1.159, 95% CI (1.04-1.30), P = 0.01]. For lung adenocarcinoma, the results also showed a close correlation between the DHA level and lung adenocarcinoma [OR = 1.277, 95% CI (1.09-1.50), P = 0.003], but it was not statistically significant for squamous cell carcinoma [OR = 1.071, 95% CI (0.89-1.29), P = 0.467].

CONCLUSIONS

Our study revealed that plasma DHA is positively associated with the risk of lung cancer overall, especially for lung adenocarcinoma. This study provides new information to develop dietary guidelines for primary lung cancer prevention.

Crosstalk between Depression and Breast Cancer via Hepatic Epoxide Metabolism: A Central Comorbidity Mechanism

Breast cancer (BC) is a serious global challenge, and depression is one of the risk factors and comorbidities of BC. Recently, the research on the comorbidity of BC and depression has focused on the dysfunction of the hypothalamic–pituitary–adrenal axis and the persistent stimulation of the inflammatory response. However, the further mechanisms for comorbidity remain unclear. Epoxide metabolism has been shown to have a regulatory function in the comorbid mechanism with scattered reports. Hence, this article reviews the role of epoxide metabolism in depression and BC. The comprehensive review discloses the imbalance in epoxide metabolism and its downstream effect shared by BC and depression, including overexpression of inflammation, upregulation of toxic diols, and disturbed lipid metabolism. These downstream effects are mainly involved in the construction of the breast malignancy microenvironment through liver regulation. This finding provides new clues on the mechanism of BC and depression comorbidity, suggesting in particular a potential relationship between the liver and BC, and provides potential evidence of comorbidity for subsequent studies on the pathological mechanism.

Association of dietary intake of n-3 polyunsaturated fatty acids with breast cancer risk in pre- and postmenopausal Chinese women

OBJECTIVE

This study aimed to evaluate the associations between breast cancer risk and intake of n-3 polyunsaturated fatty acids (PUFAs) and/or n-3 PUFA subclasses in Chinese women, and determine whether these associations varied with menopausal status or clinical characteristics.

METHODS

A hospital-based case-control study including 1,589 cases and 1,621 age-frequency-matched controls was conducted. Dietary data were assessed by a validated food frequency questionnaire. Odds ratios (ORs) and 95% confidence intervals were obtained using multiple unconditional logistic regression models after controlling for potential confounders.

RESULTS

Higher intake of marine n-3 PUFAs and total n-3 PUFAs was associated with lower risk of breast cancer, with adjusted OR quartile 4 v.1 (95% confidence intervals) of 0.68 (0.55-0.84) and 0.56 (0.42-0.75), respectively. Dietary a-linolenic acid, eicosapentaenoic acid, docosapentaenoic acid, docosahexaenoic acid were also inversely associated with breast cancer risk, with adjusted ORs (95% confidence intervals) of 0.51 (0.38-0.70), 0.68 (0.55-0.84), 0.68 (0.55-0.85), and 0.76 (0.61-0.94), respectively. In stratified analyses, these inverse associations between risk and dietary n-3 PUFAs were more evident among premenopausal women and women with ER+, PR+ and ER+PR+ tumors. A decreased risk of breast cancer was significantly associated with increasing n-3 PUFA intake in obese/overweight women, but not in women of normal weight. There was a significant interaction between linoleic acid and marine n-3 PUFAs.

CONCLUSIONS

High intake of n-3 PUFAs and n-3 PUFA subtypes was associated with a lower risk of breast cancer, especially among premenopausal women and women with ER+ and/or PR+ subtype breast cancer.

Omega-3 polyunsaturated fatty acid biomarkers and risk of type 2 diabetes, cardiovascular disease, cancer, and mortality

BACKGROUND & AIMS

Considerable attention has focused on the role of omega-3 polyunsaturated fatty acids (PUFA) in the prevention of cardiometabolic diseases, which has led to dietary recommendations to increase omega-3 fatty acid intake. A meta-analysis was conducted to summarize evidence from prospective studies regarding associations between omega-3 PUFA biomarkers and risk of developing major chronic diseases.

METHODS

Four electronic databases were searched for articles from inception to March 1, 2022. Random-effects model was used to estimate the pooled relative risk (RR) and 95% confidence intervals (CIs) for the association of omega-3 PUFAs, including α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA), with risk of developing type 2 diabetes (T2D), cardiovascular disease (CVD), including coronary heart disease (CHD) and stroke, cancer, and mortality. The Grades of Recommendation, Assessment, Development and Evaluation assessment tool was used to rates the confidence in estimates.

RESULTS

A total of 67 prospective studies comprised of 310,955 participants were identified. Individual omega-3 PUFAs showed divergent associations with the study outcomes of interest. A significant inverse association with T2D risk was observed across categories of ALA (relative risk [RR]: 0.89, 95% confidence interval [CI]: 0.82-0.96), EPA (RR: 0.85, 95% CI: 0.72-0.99) and DPA (RR: 0.84, 95% CI: 0.73-0.96) biomarkers. The marine-origin omega-3 fatty acids biomarkers but not ALA was significantly associated with lower risks of total CVD, CHD, and overall mortality, with RRs ranging from 0.70 for DHA-CHD association to 0.85 for EPA-CHD association. A lower risk of colorectal cancer was observed at higher levels of DPA (RR: 0.76, 95% CI: 0.59-0.98) and DHA (RR: 0.80; 95% CI: 0.65-0.99), whereas no association was noted for other outcomes. In addition, a dose-response relationship was observed between an increasing level of EPA, DPA, or DHA biomarker and lower risk of CVD.

CONCLUSIONS

Higher concentrations of marine-derived omega-3 PUFA biomarkers were associated with a significantly reduced risk of total CVD, CHD, and total mortality. Levels of ALA were inversely associated with a lower risk of T2D but not CVD-related outcomes. These data support the dietary recommendations advocating the role of omega-3 PUFAs in maintaining an overall lower risk of developing cardiovascular disease and premature deaths.

Serum Metabolomics Reveals Dysregulation and Diagnostic Potential of Oxylipins in Tumor-induced Osteomalacia

CONTEXT

Excessive production of fibroblast growth factor 23 (FGF23) by a tumor is considered the main pathogenesis in tumor-induced osteomalacia (TIO). Despite its importance to comprehensive understanding of pathogenesis and diagnosis, the regulation of systemic metabolism in TIO remains unclear.

OBJECTIVE

We aimed to systematically characterize the metabolome alteration associated with TIO.

METHODS

By means of liquid chromatography-tandem mass spectrometry-based metabolomics, we analyzed the metabolic profile from 96 serum samples (32 from TIO patients at initial diagnosis, pairwise samples after tumor resection, and 32 matched healthy control (HC) subjects). In order to screen and evaluate potential biomarkers, statistical analyses, pathway enrichment and receiver operating characteristic (ROC) were performed.

RESULTS

Metabolomic profiling revealed distinct alterations between TIO and HC cohorts. Differential metabolites were screened and conducted to functional clustering and annotation. A significantly enriched pathway was found involving arachidonic acid metabolism. A combination of 5 oxylipins, 4-HDoHE, leukotriene B4, 5-HETE, 17-HETE, and 9,10,13-TriHOME, demonstrated a high sensitivity and specificity panel for TIO prediction screened by random forest algorithm (AUC = 0.951; 95% CI, 0.827-1). Supported vector machine modeling and partial least squares modeling were conducted to validate the predictive capabilities of the diagnostic panel.

CONCLUSION

Metabolite profiling of TIO showed significant alterations compared with HC. A high-sensitivity and high-specificity panel with 5 oxylipins was tested as diagnostic predictor. For the first time, we provide the global profile of metabolomes and identify potential diagnostic biomarkers of TIO. The present work may offer novel insights into the pathogenesis of TIO.

Plasma Fatty Acid Composition Was Associated with Apelin Gene Expression in Human Adipose Tissues

Background

Apelin is an adipokine with an intermediatory role in obesity and insulin resistance, which can be modified by dietary intake.

Aims

In this study, we aimed to determine the association of the plasma fatty acid composition with apelin plasma concentration and gene expression in visceral (VAT) and subcutaneous (SAT) adipose tissues.

Methods

In this cross-sectional study, we recruited 179 patients aged 19-75 years who were candidates for elective surgery. Through the surgery, SAT and VAT were collected to measure apelin gene expression. Anthropometric measurements, fasting blood samples, and dietary intakes were collected before surgery. Free fatty acids (FFAs) in fasting whole plasma were measured using gas chromatography with flame ionization detection. Linear regression models were used to estimate standardized β (STZ β) showing the association of individual and total FFAs with apelin gene expression after adjustment for potential confounding variables.

Results

In multivariable analysis, we observed a significant positive association of total plasma free fatty acids (FFAs) (STZ β = 0.241, P = 0.006), saturated fatty acid (SFA) (STZ β = 0.336, P < 0.001), and monounsaturated fatty acid (MUFA) (STZ β = 0.313, P < 0.001) concentrations with apelin gene expression from VAT after controlling for age, sex, body mass index, homeostatic model assessment for insulin resistance (HOMA-IR), physical activity, and energy intake. In the SFA family, there was a direct association with plasma concentration of myristic acid (STZ β = 0.372, P < 0.001), pentadecanoic acid (STZ β = 0.252, P = 0.002), and heptadecanoic acid (STZ β = 0.407, P < 0.001) with apelin mRNA expression in VAT. There was no significant association between FFAs and apelin plasma concentration and SAT mRNA levels.

Conclusions

In conclusion, circulating plasma FFAs, SFA, and MUFA had a positive association with apelin gene expression in VAT. It seems that plasma fatty acid composition may regulate apelin gene expression in VAT.

A Prospective Analysis of Plasma Phospholipid Fatty Acids and Breast Cancer Risk in 2 Provinces in Canada

BACKGROUND

Studies suggest that fatty acid status influences breast cancer etiology, yet the roles of individual fatty acids in breast cancer risk are unclear, specifically when central adiposity and menopausal status are considered.

OBJECTIVES

This study examined the associations of fatty acid status with breast cancer risk including location, menopausal status, and waist-to-hip ratio as key variables.

METHODS

Prediagnostic plasma phospholipid fatty acids were measured in women with breast cancer (n = 393) and age-matched controls (n = 786) from a nested case-control prospective study within Alberta's Tomorrow Project (ATP) and British Columbia Generations Project (BCGP) cohorts. Binary logistic regression models were used to evaluate associations of fatty acids and breast cancer risk with subgroup analysis for menopausal status and waist-to-hip ratio.

RESULTS

Women from BCGP had a higher n-3 (ɷ-3) fatty acid status compared with the ATP (6.4% ± 0.08% vs. 5.3% ± 0.06%; P < 0.001), so subsequent analysis was blocked by cohort. Overall, fatty acids had inconsistent associations with risk. In the ATP among premenopausal women, total long-chain n-3 fatty acids (ORQ4vsQ1 = 1.78; 95% CI: 0.58, 5.43; P-trend = 0.007, P-interaction = 0.07) were positively associated with breast cancer risk, whereas in BCGP, DHA (ORQ4vsQ1 = 0.66; 95% CI: 0.28, 1.53; P-trend = 0.03, P-interaction = 0.05) and total long-chain n-3 fatty acids (ORQ4vsQ1 = 0.66; 95% CI: 0.28, 1.54; P-trend = 0.03) were associated with decreased cancer risk when the waist-to-hip ratio was <0.85.

CONCLUSIONS

Our findings suggest that regional variations in fatty acid status influence breast cancer risk, resulting in positive associations of total long-chain n-3 fatty acids in premenopausal ATP women and negative associations of these fatty acids in BCGP women with a waist-to-hip ratio below guidelines. This study highlights the complexity and difficulty in using fatty acid status to predict breast cancer risk in diverse populations without the consideration of other risk factors.

Dietary intake of trans fatty acids and breast cancer risk in 9 European countries

BACKGROUND

Trans fatty acids (TFAs) have been hypothesised to influence breast cancer risk. However, relatively few prospective studies have examined this relationship, and well-powered analyses according to hormone receptor-defined molecular subtypes, menopausal status, and body size have rarely been conducted.

METHODS

In the European Prospective Investigation into Cancer and Nutrition (EPIC), we investigated the associations between dietary intakes of TFAs (industrial trans fatty acids [ITFAs] and ruminant trans fatty acids [RTFAs]) and breast cancer risk among 318,607 women. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models, adjusted for other breast cancer risk factors.

RESULTS

After a median follow-up of 8.1 years, 13,241 breast cancer cases occurred. In the multivariable-adjusted model, higher total ITFA intake was associated with elevated breast cancer risk (HR for highest vs lowest quintile, 1.14, 95% CI 1.06-1.23; P trend = 0.001). A similar positive association was found between intake of elaidic acid, the predominant ITFA, and breast cancer risk (HR for highest vs lowest quintile, 1.14, 95% CI 1.06-1.23; P trend = 0.001). Intake of total RTFAs was also associated with higher breast cancer risk (HR for highest vs lowest quintile, 1.09, 95% CI 1.01-1.17; P trend = 0.015). For individual RTFAs, we found positive associations with breast cancer risk for dietary intakes of two strongly correlated fatty acids (Spearman correlation r = 0.77), conjugated linoleic acid (HR for highest vs lowest quintile, 1.11, 95% CI 1.03-1.20; P trend = 0.001) and palmitelaidic acid (HR for highest vs lowest quintile, 1.08, 95% CI 1.01-1.16; P trend = 0.028). Similar associations were found for total ITFAs and RTFAs with breast cancer risk according to menopausal status, body mass index, and breast cancer subtypes.

CONCLUSIONS

These results support the hypothesis that higher dietary intakes of ITFAs, in particular elaidic acid, are associated with elevated breast cancer risk. Due to the high correlation between conjugated linoleic acid and palmitelaidic acid, we were unable to disentangle the positive associations found for these fatty acids with breast cancer risk. Further mechanistic studies are needed to identify biological pathways that may underlie these associations.

A 16-Channel 13C Array Coil for Magnetic Resonance Spectroscopy of the Breast at 7T

OBJECTIVE

Considering the reported elevation of ω-6/ω-3 fatty acid ratios in breast neoplasms, one particularly important application of ¹³C MRS could be in more fully understanding the breast lipidome's relationship to breast cancer incidence. However, the low natural abundance and gyromagnetic ratio of the ¹³C isotope lead to detection sensitivity challenges. Previous ¹³C MRS studies have relied on the use of small surface coils with limited field-of-view and shallow penetration depths to achieve adequate signal-to-noise ratio (SNR), and the use of receive array coils is still mostly unexplored.

METHODS

This work presents a unilateral breast 16-channel ¹³C array coil and interfacing hardware designed to retain the surface sensitivity of a single small loop coil while improving penetration depth and extending the field-of-view over the entire breast at 7T. The coil was characterized through bench measurements and phantom ¹³C spectroscopy experiments.

RESULTS

Bench measurements showed receive coil matching better than -17 dB and average preamplifier decoupling of 16.2 dB with no evident peak splitting. Phantom MRS studies show better than a three-fold increase in average SNR over the entirety of the breast region compared to volume coil reception alone as well as an ability for individual array elements to be used for coarse metabolite localization without the use of single-voxel or spectroscopic imaging methods.

CONCLUSION

Our current study has shown the benefits of the array. Future in vivo lipidomics studies can be pursued.

SIGNIFICANCE

Development of the 16-channel breast array coil opens possibilities of in vivo lipidomics studies to elucidate the link between breast cancer incidence and lipid metabolics.

Her-2 Breast Cancer Outcomes Are Mitigated by Consuming n-3 Polyunsaturated, Saturated, and Monounsaturated Fatty Acids Compared to n-6 Polyunsaturated Fatty Acids

Lifestyle habits, such as the consumption of a healthy diet, may prevent up to 30–50% of breast cancer (BC) cases. Dietary fats are of specific interest, as research provides strong evidence regarding the association of dietary fats and BC. However, there is limited research on the role of different types of fats including polyunsaturated (PUFA), monounsaturated (MUFA), and saturated fatty acids (SFA). The objective of this study was to determine the effects of lifelong exposure to various dietary fats on mammary tumour development over a 20-week period. Female heterozygous MMTV-neu (ndl) YD5 mouse models were fed five maternal diets containing (1) 10% safflower oil (n-6 PUFA, control), (2) 3% menhaden oil + 7% safflower oil (marine n-3 PUFA, control), (3) 3% flaxseed + 7% safflower oil (plant-based n-3 PUFA), (4) 10% olive oil (MUFA), or (5) 10% lard (SFA). The primary measures, tumour latency, volume, and multiplicity differed by diet treatment in the following general order, n-6 PUFA > plant n-3 PUFA, SFA, MUFA > marine n-3 PUFA. Overall, these findings show that the quality of the diet plays a significant role influencing mammary tumour outcomes.

Evaluation of the eating habits of breast cancer patients

Objective:

To determine the relationship between the dietary characteristics of breast cancer patients.

Methods:

Patients with breast cancer whose treatments have finished and are in remission formed the study group and healthy people formed the control group. Demographic, anthropometric characteristics, food consumption frequency form and exercise status were recorded with all groups. Data analysis was done by SPSS 22.

Results:

In the study group, mean carbohydrate percentage was lower, while fat, fat percentage, monosaccharide, glucose, fructose, omega3(n3), saturated fatty acids(SFA), monounsaturated fatty acids (MUFA), vitamin A, C, E, B6, biotin and copper values were significantly higher (p<0.05). Recurrence was observed in seven patients (7.1%) during the follow-up period, hormone receptor levels (ER) and vitamin B2 intake (accuracy 93.9%) were inversely related to the recurrence of the disease (p=0.02).

Conclusions:

While the percentage of carbohydrate taken was lower in study group; total fat, n3, SFA, MUFA, monosaccharide, glucose, fructose, water-soluble fiber, B6, biotin and copper values were higher. Further studies are needed for vitamin B2 deficiency in patients with recurrence

Serum Phospholipids Fatty Acids and Breast Cancer Risk by Pathological Subtype

This study evaluates whether serum phospholipids fatty acids (PL-FAs) and markers of their endogenous metabolism are associated with breast cancer (BC) subtypes. EpiGEICAM is a Spanish multicenter matched case-control study. A lifestyle and food frequency questionnaire was completed by 1017 BC cases and healthy women pairs. Serum PL-FA percentages were measured by gas chromatography-mass spectrometry. Conditional and multinomial logistic regression models were used to quantify the association of PL-FA tertiles with BC risk, overall and by pathological subtype (luminal, HER2+ and triple negative). Stratified analyses by body mass index and menopausal status were also performed. Serum PL-FAs were measured in 795 (78%) pairs. Women with high serum levels of stearic acid (odds ratio (OR)_T3vsT1 = 0.44; 95% confidence interval (CI) = 0.30–0.66), linoleic acid (OR_T3vsT1 = 0.66; 95% CI = 0.49–0.90) and arachidonic to dihomo-γ-linolenic acid ratio (OR _T3vsT1 = 0.64; 95% CI = 0.48–0.84) presented lower BC risk. Participants with high concentrations of palmitoleic acid (OR_T3vsT1 = 1.65; 95% CI = 1.20–2.26), trans-ruminant palmitelaidic acid (OR_T3vsT1 = 1.51; 95% CI = 1.12–2.02), trans-industrial elaidic acid (OR_T3vsT1 = 1.52; 95% CI = 1.14–2.03), and high oleic to stearic acid ratio (OR_T3vsT1 = 2.04; 95% CI = 1.45–2.87) showed higher risk. These associations were similar in all BC pathological subtypes. Our results emphasize the importance of analyzing fatty acids individually, as well as the desaturase activity indices.

N-6 Polyunsaturated Fatty Acids and Risk of Cancer: Accumulating Evidence from Prospective Studies

Previous studies on the association between polyunsaturated fatty acids (PUFAs) and cancer have focused on n-3 PUFAs. To investigate the association between intake or blood levels of n-6 PUFAs and cancer, we searched the PubMed and Embase databases up to March 2020 and conducted a meta-analysis. A total of 70 articles were identified. High blood levels of n-6 PUFAs were associated with an 8% lower risk of all cancers (relative risk (RR) = 0.92; 95% confidence interval (CI): 0.86-0.98) compared to low blood levels of n-6 PUFAs. In the subgroup analyses by cancer site, type of n-6 PUFAs, and sex, the inverse associations were strong for breast cancer (RR = 0.87; 95% CI: 0.77-0.98), linoleic acid (LA) (RR = 0.91; 95% CI: 0.82-1.00), and women (RR = 0.88; 95% CI: 0.79-0.97). In the dose-response analysis, a 2% and 3% decrease in the risk of cancer was observed with a 5% increase in blood levels of n-6 PUFAs and LA, respectively. Thus, there was no significant association between n-6 PUFA intake and the risk of cancer. The pooled RR of cancer for the highest versus lowest category of n-6 PUFA intake was 1.02 (95% CI: 0.99-1.05). Evidence from prospective studies indicated that intake of n-6 PUFAs was not significantly associated with risk of cancer, but blood levels of n-6 PUFAs were inversely associated with risk of cancer.

Erythrocyte membrane fatty acids and breast cancer risk by tumor tissue expression of immuno-inflammatory markers and fatty acid synthase: a nested case-control study

BACKGROUND

Previous studies of fatty acids and breast cancer risk have shown mixed results, which may be due in part to tumor heterogeneity. Prior research has also illustrated an important role of specific fatty acids in immune regulation, T cell function, and inflammation, indicating that the effects of specific fatty acids on breast cancer risk may vary by tumor expression of immuno-inflammatory markers. We therefore aimed to evaluate the relationships between prediagnostic erythrocyte membrane fatty acids and breast cancer risk by tumor tissue expression of immuno-inflammatory markers (CD4, CD8, CD20, CD163, COX-2) and fatty acid synthase (FAS).

METHODS

We conducted a matched case-control study nested within the Nurses' Health Study II (n = 235 cases and 235 controls). Blood samples were collected from 1996 to 1999. Tumor tissue blocks were collected for cases diagnosed after blood collection and through 2006. Unconditional nominal polytomous logistic regression adjusted for matching factors and potential confounders was used to assess whether associations between fatty acids and breast cancer risk varied by tumor expression subtype, ascertained via immunohistochemistry. Odds ratios (OR) and 95% confidence intervals (CI) were estimated separately by tumor expression subtype using unconditional logistic regression.

RESULTS

Associations between fatty acids and breast cancer risk did not vary substantially by tumor CD4, CD20, CD163, or COX-2. However, n-3 polyunsaturated fatty acids (PUFAs) were inversely associated with CD8^low but not CD8^high cancers (CD8^low OR_{T3 vs T1} = 0.45, 95% CI 0.23-0.87, P_trend = 0.02; CD8^high OR_{T3 vs T1} = 1.19, 95% CI 0.62-2.26, P_trend = 0.62; P_het = 0.04). n-6 PUFAs were suggestively inversely associated with CD8^high but not CD8^low cancers (CD8^high OR_{T3 vs T1} = 0.61, 95% CI 0.32-1.14, P_trend = 0.11; CD8^low OR_{T3 vs T1} = 1.63, 95% CI 0.87-3.04, P_trend = 0.12; P_het = 0.02). Trans fatty acids were positively associated with FAS^high but not FAS^low tumors (FAS^high OR_{T3 vs T1} = 2.94, 95% CI 1.46-5.91, P_trend = 0.002; FAS^low OR_{T3 vs T1} = 0.99, 95% CI 0.52-1.92, P_trend = 0.97; P_het = 0.01).

CONCLUSION

Results indicate that the effects of n-3 PUFAs, n-6 PUFAs, and trans fatty acids on breast cancer risk may vary by tumor tissue expression subtypes. Findings suggest potential immuno-modulatory and FAS-mediated mechanisms.

Dietary Fat and Cancer-Which Is Good, Which Is Bad, and the Body of Evidence

A high-fat diet (HFD) induces changes in gut microbiota leading to activation of pro-inflammatory pathways, and obesity, as a consequence of overnutrition, exacerbates inflammation, a known risk factor not only for cancer. However, experimental data showed that the composition of dietary fat has a greater impact on the pathogenesis of cancer than the total fat content in isocaloric diets. Similarly, human studies did not prove that a decrease in total fat intake is an effective strategy to combat cancer. Saturated fat has long been considered as harmful, but the current consensus is that moderate intake of saturated fatty acids (SFAs), including palmitic acid (PA), does not pose a health risk within a balanced diet. In regard to monounsaturated fat, plant sources are recommended. The consumption of plant monounsaturated fatty acids (MUFAs), particularly from olive oil, has been associated with lower cancer risk. Similarly, the replacement of animal MUFAs with plant MUFAs decreased cancer mortality. The impact of polyunsaturated fatty acids (PUFAs) on cancer risk depends on the ratio between ω-6 and ω-3 PUFAs. In vivo data showed stimulatory effects of ω-6 PUFAs on tumour growth while ω-3 PUFAs were protective, but the results of human studies were not as promising as indicated in preclinical reports. As for trans FAs (TFAs), experimental data mostly showed opposite effects of industrially produced and natural TFAs, with the latter being protective against cancer progression, but human data are mixed, and no clear conclusion can be made. Further studies are warranted to establish the role of FAs in the control of cell growth in order to find an effective strategy for cancer prevention/treatment.

A Scoping Review of Interactions between Omega-3 Long-Chain Polyunsaturated Fatty Acids and Genetic Variation in Relation to Cancer Risk

This scoping review examines the interaction of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) and genetic variants of various types of cancers. A comprehensive search was performed to identify controlled and observational studies conducted through August 2017. Eighteen unique studies were included: breast cancer (n = 2), gastric cancer (n = 1), exocrine pancreatic cancer (n = 1), chronic lymphocytic leukemia (n = 1), prostate cancer (n = 7) and colorectal cancer (n = 6). An additional 13 studies that focused on fish intake or at-risk populations were summarized to increase readers’ understanding of the topic based on this review, DHA and EPA interact with certain genetic variants to decrease breast, colorectal and prostate cancer risk, although data was limited and identified polymorphisms were heterogeneous. The evidence to date demonstrates that omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) may decrease cancer risk by affecting genetic variants of inflammatory pathways, oxidative stress and tumor apoptosis. Collectively, data supports the notion that once a genetic variant is identified, the benefits of a targeted, personalized therapeutic regimen that includes DHA and/or EPA should be considered.

Alcohol consumption and serum metabolite concentrations in young women

PURPOSE

Alcohol consumption is an established breast cancer risk factor, though further research is needed to advance our understanding of the mechanism underlying the association. We used global metabolomics profiling to identify serum metabolites and metabolic pathways that could potentially mediate the alcohol-breast cancer association.

METHODS

A cross-sectional analysis of reported alcohol consumption and serum metabolite concentrations was conducted among 211 healthy women 25-29 years old who participated in the Dietary Intervention Study in Children 2006 Follow-Up Study (DISC06). Alcohol-metabolite associations were evaluated using multivariable linear mixed-effects regression.

RESULTS

Alcohol was significantly (FDR p < 0.05) associated with several serum metabolites after adjustment for diet composition and other potential confounders. The amino acid sarcosine, the omega-3 fatty acid eicosapentaenoate, and the steroid 4-androsten-3beta,17beta-diol monosulfate were positively associated with alcohol intake, while the gamma-tocopherol metabolite gamma-carboxyethyl hydroxychroman (CEHC) was inversely associated. Positive associations of alcohol with 2-methylcitrate and 4-androsten-3beta,17beta-diol disulfate were borderline significant (FDR p < 0.10). Metabolite set enrichment analysis identified steroids and the glycine pathway as having more members associated with alcohol consumption than expected by chance.

CONCLUSIONS

Most of the metabolites associated with alcohol in the current analysis participate in pathways hypothesized to mediate the alcohol-breast cancer association including hormonal, one-carbon metabolism, and oxidative stress pathways, but they could also affect risk via alternative pathways. Independent replication of alcohol-metabolite associations and prospective evaluation of confirmed associations with breast cancer risk are needed.

Cross-sectional study of the combined associations of dietary and supplemental eicosapentaenoic acid + docosahexaenoic acid on Omega-3 Index

Studies have linked an Omega-3 Index (O3I), which measures eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) in red blood cell membranes, of ≥8% with improved health. Previous studies found that the American Heart Association (AHA) recommendation of 1-2 seafood meals per week does not achieve an O3I ≥8% even with an EPA + DHA supplement; however, these studies did not assess the frequency or amount of supplemental intake. Among participants in a predominantly US and Canadian cohort with high nutrient supplement use, we hypothesized that those adhering to the AHA guidelines would not have an average O3I ≥8% but that those taking a daily supplement would. Fish consumption and EPA + DHA supplement use were reported by 1795 participants; 985 also completed a blood spot test for O3I. A majority (71%) consumed <2 servings per week of fatty fish, and 61% took an EPA + DHA supplement. The amount of EPA + DHA for 1 serving (based on the product label) significantly differed among the >400 supplement products (50-3570 mg). O3I was ≥8.0% in 19% of participants. Among non-supplement takers, 3% of those consuming 1 fish serving per week and 17% consuming ≥2 achieved an O3I ≥8.0%. Among those consuming ≥2 fish servings per week, only those also taking an average of 1100 mg/d of supplemental EPA + DHA had a median O3I ≥8.0%. Based on the relationship between supplemental EPA + DHA intake and O3I for non-fish eaters (R² = 0.40, P < .0001), an average of ~1300 mg/d of EPA + DHA achieved an O3I of 8.0%. This study suggests that following the AHA guidelines does not produce an O3I ≥8% nor does taking 1 serving per day of most omega-3 supplements.

Changes in dietary intake, plasma carotenoids and erythrocyte membrane fatty acids in breast cancer survivors after a lifestyle intervention: results from a single-arm trial

BACKGROUND

The influence of nutrition on breast cancer prognosis is still inconclusive and therefore dietary interventions incorporating dietary biomarkers are needed to confirm compliance with dietary goals and clarify biological mechanisms. The present study assessed whether a lifestyle intervention in breast cancer survivors could affect dietary biomarkers of fruit and vegetables and fatty acids.

METHODS

In this phase II single-arm trial, 37 overweight/obese early stage breast cancer patients completed a 12-week diet and exercise intervention. The intervention involved 1-h weekly diet sessions delivered by a dietician and 75-min bi-weekly physical activity sessions of moderate-to-high intensity led by trained monitors. Before and after the intervention, three 24-h dietary recalls were carried out to calculate nutrient intakes and, in addition, blood samples were taken to measure plasma carotenoids, vitamin E and retinol concentrations and erythrocyte membrane fatty acid (EFA) composition. Wilcoxon signed rank tests were used to assess changes in dietary and biomarkers measurements over the intervention period.

RESULTS

After the intervention, there was a significant increase in the intake of dietary carotenoids (+15.1% compared to baseline) but not plasma carotenoids levels (+6.3%). Regarding the EFA levels, we observed a significant decrease in percentage of saturated fatty acids (-1.4%) and n-6 polyunsaturated fatty acids (-2.9%) and an increase in monounsaturated fatty acids (1.7%) and total and long-chain n-3 polyunsaturated fatty acids (by 13.1% and 13.7%, respectively). A favourable decrease in the ratio of long-chain n-6 to n-3 polyunsaturated fatty acids (-9.1%) was also observed.

CONCLUSIONS

After a short-term diet and exercise intervention in overweight/obese breast cancer survivors, we observed significant changes in dietary nutrients and fatty acid biomarkers, suggesting positive dietary changes that could be relevant for breast cancer prognosis.

Fatty acids distribution and content in oral squamous cell carcinoma tissue and its adjacent microenvironment

Squamous cell carcinoma of the oral cavity mucosa grows under conditions of poor oxygenation and nutrient scarcity. Reprogramming of lipid biosynthesis accompanies tumor growth, but the conditions under which it occurs are not fully understood. The fatty acid content of the serum, tumor tissue and adjacent tumor microenvironment was measured by gas chromatography in 30 patients with squamous cell carcinoma grade 1-3. Twenty-five fatty acids were identified; their frequencies and percentages in each of the environments were assessed. Nineteen of the twenty-five fatty acids were found in tumor tissue, tumor adjacent tissue and blood serum. Of them, 8 were found in all thirty patients. Percentages of C16:0 and C18:1n9 were highest in the tumor, C18:1n9 and C16:0 were highest in tumor adjacent tissue, and C16:0 and C18:0 were highest in blood serum. The frequencies and amounts of C22:1n13, C22:4n6, C22:5n3 and C24:1 in tumor adjacent tissues were higher than those in blood serum, independent of the tumor grade. The correlations between the amount of fatty acid and tumor grade were the strongest in tumor adjacent tissues. The correlations between particular fatty acids were most prevalent for grade 1+2 tumors and were strongest for grade 3 tumors. In the adjacent tumor microenvironment, lipogenesis was controlled by C22:6w3. In blood serum, C18:1trans11 limited the synthesis of long-chain fatty acids. Our research reveals intensive lipid changes in oral cavity SCC adjacent to the tumor microenvironment and blood serum of the patients. Increase in percentage of some of the FAs in the path: blood serum-tumor adjacent microenvironment-tumor, and it is dependent on tumor grade. This dependency is the most visible in the tumor adjacent environment.

Fatty acid intake and breast cancer in the Spanish multicase-control study on cancer (MCC-Spain)

PURPOSE

To evaluate the association between dietary fat and fat subtype and breast cancer development.

METHODS

We conducted a case-control study with 1181 cases of incident breast cancer, diagnosed between 2007 and 2012, and 1682 population controls frequency matched (by age, sex, and region) from the Spanish multicenter case-control study MCC-Spain.

RESULTS

We found a significant protective effect in premenopausal women of total fat intake [OR 0.51 95% CI (0.31-0.86) highest versus lowest tertile], but no effect was observed in menopausal women [OR 1.15 95% CI (0.83-1.60)]. Analyzing by type of fat, this protective effect persisted only for the monounsaturated fatty acids [OR 0.51 95% CI (0.32-0.82)]. In contrast, other fatty acids did not have a significant effect. In addition, a protection against risk of breast cancer was found when polyunsaturated fats were "substituted" by monounsaturated, maintaining the same total fat intake [OR 0.68 95% CI (0.47-0.99)]. Finally, analyzing by breast cancer subtype, we found no effect, except in premenopausal women where intake of moderate [OR 0.52 95% CI (0.33-0.82)] and high monounsaturated fatty acids [OR 0.47 95% CI (0.27-0.82)] maintains a protective effect against ER/PR + tumors. In contrast, in menopausal women, a high intake of monounsaturated fatty acids was associated with higher risk of HER2 + tumors [OR 2.00 95% CI (0.97-4.13)].

CONCLUSION

Our study shows a differential effect of monounsaturated fatty acids according to menopausal status and breast cancer subtype.

Dietary intake and serum levels of trans fatty acids and risk of breast cancer: A systematic review and dose-response meta-analysis of prospective studies

BACKGROUND & AIMS

Although the relationship between dietary intake and serum levels of trans fatty acids and risk of breast cancer has been investigated extensively, findings are inconsistent. To summarize earlier findings on the association of dietary intake and serum levels of trans fatty acids with risk of breast cancer through a dose-response meta-analysis.

METHODS

The online databases of PubMed, ISI Web of Science, Scopus, ProQuest, Science Direct and Embase were searched for relevant publications up to June 2018, using MeSH and non-MeSH keywords. In total, 7 prospective studies [6 cohort studies and one nested case-control study] were included on total dietary trans fat intake, and five studies [1 cohort study and 4 nested case-control studies] were included about serum trans fatty acids. Assessment of study quality was conducted using the Newcastle-Ottawa scale. Study-specific RRs were combined via fixed-effects model to compute overall RRs.

RESULTS

Participants were apparently healthy aged 26 years or older. We observed no significant relationship between dietary intake of total trans fatty acids and risk of breast cancer (pooled effect size: 1.02, 95% CI: 0.95-1.10, P = 0.403). Combining 3 effect sizes from 2 prospective and one nested case-control study, no significant relation was seen between dietary intake of CLA and risk of breast cancer (pooled effect size: 1.05, 95% CI: 0.95-1.17, P = 0.513). Based on 5 effect sizes, each additional 1 g/day dietary intake of total trans fats was not significantly associated with risk of breast cancer (RR = 1.00; 95% CI = 0.99-1.01). In addition, it seems that serum levels of trans fats might be associated with an increased risk of breast cancer only among postmenopausal women (Pooled effect size: 1.37, 95% CI: 1.04-1.81, P = 0.02).

CONCLUSIONS

In conclusion, dietary intake of trans fatty acids was not associated with risk of breast cancer; however, a significant positive association was seen between serum trans fats and risk of breast cancer in postmenopausal women.

A Novel Clinical Six-Flavoprotein-Gene Signature Predicts Prognosis in Esophageal Squamous Cell Carcinoma

Flavoproteins and their interacting proteins play important roles in mitochondrial electron transport, fatty acid degradation, and redox regulation. However, their clinical significance and function in esophageal squamous cell carcinoma (ESCC) are little known. Here, using survival analysis and machine learning, we mined 179 patient expression profiles with ESCC in GSE53625 from the Gene Expression Omnibus (GEO) database and constructed a signature consisting of two flavoprotein genes (GPD2 and PYROXD2) and four flavoprotein interacting protein genes (CTTN, GGH, SRC, and SYNJ2BP). Kaplan-Meier analysis revealed the signature was significantly associated with the survival of ESCC patients (mean survival time: 26.77 months in the high-risk group vs. 54.97 months in the low-risk group, P < 0.001, n = 179), and time-dependent ROC analysis demonstrated that the six-gene signature had good predictive ability for six-year survival for ESCC (AUC = 0.86, 95% CI: 0.81-0.90). We then validated its prediction performance in an independent set by RT-PCR (mean survival: 15.73 months in the high-risk group vs. 21.1 months in the low-risk group, P=0.032, n = 121). Furthermore, RNAi-mediated knockdown of genes in the flavoprotein signature led to decreased proliferation and migration of ESCC cells. Taken together, CTTN, GGH, GPD2, PYROXD2, SRC, and SYNJ2BP have an important clinical significance for prognosis of ESCC patients, suggesting they are efficient prognostic markers and potential targets for ESCC therapy.

Differential Potentiation of Retinoic Acid Effects against Human Breast Cancer Cells by Unsaturated Fatty Acids

Retinoic acid (RA) and unsaturated fatty acids (UFA) are proposed as nutritional anticancer agents. Nonetheless, the activity of their combination on human breast cancer needs further study. Our aim was to evaluate this activity on the MCF-7 and ZR-75-1 cell lines treated with 1 µM RA and 50 µM of γ-linoleic (GLA, ω-6), eicosapentaenoic (EPA, ω-3), oleic (OA, ω-9), or eicosatrienoic (ETA, ω-9) acids. The following cellular responses were compared by ANOVA and Fisher test (P < 0.05): fatty acids, E-cadherin, actin (differentiation), conjugated dienes, γ-glutamyltranspeptidase activity (stress), and viability, which were correlated by partial least squares regression. Although both cell lines responded differentially, RA modified unsaturated fatty acids, increased differentiation, reduced γ-glutamyltranspeptidase, and viability. RA differentiating activity on ZR-75-1 was morphologically enhanced by UFA. Stress induction with γ-glutamyltranspeptidase decrease and conjugated dienes was promoted by ETA in MCF-7, and EPA and OA in ZR-75-1. RA-related reduced viability was potentiated by EPA and OA in both lines. GLA was less active. Therefore, unsaturated fatty acids (ω-3/ω-9) potentiated the multitarget retinoic acid activity against these human breast cancer cells.

Decreased Oleic Acid and Marine n - 3 Polyunsaturated Fatty Acids in Tunisian Patients with Urothelial Bladder Cancer

Fatty acids (FAs) are thought to impact carcinogenesis by affecting cell signaling. A case-control study including 250 patients with urothelial bladder cancer (UBC) and 250 controls was conducted. Plasma FAs composition was assessed using capillary gas chromatography. Associations of individual and classes of FAs with UBC were controlled for the main risk factors for UBC. Plasma FAs profile was different in patients compared to controls. Higher levels (third tertile vs. first tertile) in palmitic acid (PA) [multi-adjusted OR (95% CI), 1.83 (1.14-2.92)], and n - 6:n - 3 FA ratio [4.13 (2.38-7.16)] were associated with increased risk for UBC [multi-adjusted OR (95% CI), 1.83 (1.14-2.92)]. In contrast, higher levels (third tertile vs. first tertile) in oleic [0.54 (0.34-0.86)], dihomo-γ-linolenic (DGLA) [0.47 (0.29-0.74)], eicosapentaenoic (EPA) [0.32 (0.19-0.52)], and docosahexaenoic (DHA) acids [0.33 (0.20-0.53)] were associated with lower risk for UBC. Although the study design does not allow proving causality, the findings suggest a possible protective role of oleic acid and marine n - 3 polyunsaturated FAs (PUFAs) against bladder carcinogenesis.

Differentiating the biological effects of linoleic acid from arachidonic acid in health and disease

Dietary fatty acids are associated with the development of many chronic diseases, such as obesity, diabetes, cardiovascular disease, metabolic syndrome, and several cancers. This review explores the literature surrounding the combined and individual roles of n-6 PUFAs linoleic acid (LA) and arachidonic acid (AA) as they relate to immune and inflammatory response, cardiovascular health, liver health, and cancer. The evidence suggests that a pro-inflammatory view of LA and AA may be over simplified. Overall, this review highlights gaps in our understanding of the biological roles of LA, AA and their complex relationship with n-3 PUFA and the need for future studies that examine the roles of individual fatty acids, rather than groups.

Biomarker of long-chain n-3 fatty acid intake and breast cancer: Accumulative evidence from an updated meta-analysis of epidemiological studies

Objective: We aimed to summarize the up-to-date epidemiology evidence on biomarkers of long-chain (LC) n-3 fatty acid (FA) intake in relation to breast cancer (BC).Methods: Epidemiology studies determining FA levels in biospecimen (circulating blood or adipose tissue (AT)) were identified from PubMed, EMBASE, and Cochrane Library databases until March 2018. Multivariate-adjusted risk ratios (RRs) with 95% confidence intervals (CIs) were pooled using a random-effect model. Difference in biospecimen proportions of LC n-3 FA between BC cases and non-cases were analyzed as a standardized mean difference (SMD).Results: Thirteen cohort and eleven case-control studies were eligible for the present meta-analysis. The estimated SMD was -0.14 (95% CI: -0.27, -0.11) for LC n-3 FA and -0.27 (95% CI: -0.42, -0.11) for LC n-3/n-6 FA ratio. When comparing the top tertiles with the bottom baseline levels, circulating LC n-3 FA was significantly associated with a lower risk of BC (RR: 0.84, 95% CI: 0.74, 0.96), but not AT (RR: 1.02, 95% CI: 0.70, 1.48). Significant inverse dose-response associations were observed for each 1% increment of circulating 20:5n-3 and 22:6n-3.Conclusion: This meta-analysis highlights that circulating LC n-3 FA as a biomarker of intake may be an independent predictive factor for BC, especially 20:5n-3 and 22:6n-3.

Saturated, mono- and polyunsaturated fatty acid intake and cancer risk: results from the French prospective cohort NutriNet-Santé

PURPOSE

Lipid intakes such as saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids have been widely studied regarding cardiovascular health, but their relevance to cancer is unclear. Inconsistent epidemiological results may be explained by varied mechanisms involving PUFAs and redox balance, inflammatory status and cell signalling, along with interactions with other dietary components such as antioxidants, dietary fibre and more generally fruits and vegetable intakes. Therefore, this study aimed to investigate the associations between lipid intakes and cancer risk, and their potential modulation by vitamin C, vitamin E, dietary fibre and fruit and vegetable intakes.

METHODS

This prospective study included 44,039 participants aged ≥ 45 years from the NutriNet-Santé cohort (2009-2017). Dietary data were collected using repeated 24 h-dietary records. Multivariable Cox models were performed to characterize associations.

RESULTS

SFA intake was associated with increased overall [n = 1722 cases, HR_Q5vsQ1 = 1.44 (1.10-1.87), p-trend = 0.008] and breast [n = 545 cases, HR_Q5vsQ1 = 1.98 (1.24-3.17), p-trend = 0.01] cancer risks. n-6 PUFA [HR_Q5vsQ1 = 0.56 (0.32-0.97), p-trend = 0.01] and MUFA (HR_Q5vsQ1 = 0.41 [0.18-0.0.95), p-trend = 0.009] intakes were associated with a decreased risk of digestive cancers (n = 190 cases). Associations between n-6 PUFA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intakes and digestive cancer risk were modulated by dietary fibre, vitamin C and fruit and vegetable intakes.

CONCLUSION

These findings suggested that SFA intake could increase overall and breast cancer risks while some unsaturated fatty acids could decrease digestive cancer risk. However, in line with mechanistic hypotheses, our results suggest that intakes of fruits and vegetables and their constituents (antioxidants, fibre) may interact with PUFAs to modulate these associations.

Association of low penetrance vitamin D receptor Tru9I (rs757343) gene polymorphism with risk of premenopausal breast cancer

Objective The aim of this study was to determine whether a novel polymorphism ( Tru9I) in the low penetrance vitamin D receptor (VDR) gene is associated with risk of premenopausal breast cancer (BC). Methods This case-control study included 228 patients with BC and 503 healthy women living in Pakistan who were analyzed for the VDR Tru9I (rs757343) single nucleotide polymorphism. BC cases were histopathologically confirmed, and all healthy controls were age-matched with patients (age range, 20-45 years). DNA was extracted, and the polymerase chain reaction and restriction fragment length polymorphism assays were performed. Results The VDR Tru9I polymorphism was not significantly associated with premenopausal BC. However, the risk of BC was associated with the 'uu' genotype (odds ratio [OR], 1.141; 95% confidence interval [95% CI], 0.206-6.317). Further, mutant Tru9I was significantly associated with Grade IV carcinoma (OR, 5.36; 95% CI, 1.181-24.338). Conclusion The VDR Tru9I 'uu' genotype may increase the risk of premenopausal BC.

Long-chain omega-3 fatty acids and cancer: any cause for concern?

PURPOSE OF REVIEW

Recently, concerns have been raised with regard to the recommended doses of marine long-chain omega-3 polyunsaturated fatty acids (LC-omega-3 PUFAs) especially in relation to cancer risk and treatment. There is urgent need to clarify this point. This review considers the most recent evidence related to the potential risk of developing cancer with high LC-omega-3 PUFA intakes, and possible research strategies to better elucidate this matter.

RECENT FINDINGS

The latest published recommendations have still highlighted the usefulness of an increased dietary intake of LC-omega-3 PUFAs for the prevention of some cardiovascular diseases. However, LC-omega-3 PUFAs have been related to the potential development and progression of cancer, and considerable debate exists on this issue.

SUMMARY

The use of biomarkers reflecting the intake of LC-omega-3 PUFAs as cancer risk markers is discussed, as well as the possibility that the reported beneficial/deleterious effects may be confined to specific subpopulations on the basis of genetic, metabolic, and nutritional characteristics. Recent advances on new strategies for a safer intake of LC-omega-3 PUFAs will be considered, as their dietary sources may be contaminated by toxic/carcinogenic compounds. Potentially future directions in this important research area are also discussed.

Implications of dietary ω-3 and ω-6 polyunsaturated fatty acids in breast cancer

Breast cancer represents one of the most common forms of cancer in women worldwide, with an increase in the number of newly diagnosed patients in the last decade. The role of fatty acids, particularly of a diet rich in ω-3 and ω-6 polyunsaturated fatty acids (PUFAs), in breast cancer development is not fully understood and remains controversial due to their complex mechanism of action. However, a large number of animal models and cell culture studies have demonstrated that high levels of ω-3 PUFAs have an inhibitory role in the development and progression of breast cancer, compared to ω-6 PUFAs. The present review focused on recent studies regarding the correlation between dietary PUFAs and breast cancer development, and aimed to emphasize the main molecular mechanisms involved in the modification of cell membrane structure and function, modulation of signal transduction pathways, gene expression regulation, and antiangiogenic and antimetastatic effects. Furthermore, the anticancer role of ω-3 PUFAs through the modulation of microRNA expression levels was also reviewed.

Palmitic Acid: Physiological Role, Metabolism and Nutritional Implications

Palmitic acid (PA) has been for long time negatively depicted for its putative detrimental health effects, shadowing its multiple crucial physiological activities. PA is the most common saturated fatty acid accounting for 20–30% of total fatty acids in the human body and can be provided in the diet or synthesized endogenously via de novo lipogenesis (DNL). PA tissue content seems to be controlled around a well-defined concentration, and changes in its intake do not influence significantly its tissue concentration because the exogenous source is counterbalanced by PA endogenous biosynthesis. Particular physiopathological conditions and nutritional factors may strongly induce DNL, resulting in increased tissue content of PA and disrupted homeostatic control of its tissue concentration. The tight homeostatic control of PA tissue concentration is likely related to its fundamental physiological role to guarantee membrane physical properties but also to consent protein palmitoylation, palmitoylethanolamide (PEA) biosynthesis, and in the lung an efficient surfactant activity. In order to maintain membrane phospholipids (PL) balance may be crucial an optimal intake of PA in a certain ratio with unsaturated fatty acids, especially PUFAs of both n-6 and n-3 families. However, in presence of other factors such as positive energy balance, excessive intake of carbohydrates (in particular mono and disaccharides), and a sedentary lifestyle, the mechanisms to maintain a steady state of PA concentration may be disrupted leading to an over accumulation of tissue PA resulting in dyslipidemia, hyperglycemia, increased ectopic fat accumulation and increased inflammatory tone via toll-like receptor 4. It is therefore likely that the controversial data on the association of dietary PA with detrimental health effects, may be related to an excessive imbalance of dietary PA/PUFA ratio which, in certain physiopathological conditions, and in presence of an enhanced DNL, may further accelerate these deleterious effects.

Correlation between Oxidative Stress, Nutrition, and Cancer Initiation

Inadequate or excessive nutrient consumption leads to oxidative stress, which may disrupt oxidative homeostasis, activate a cascade of molecular pathways, and alter the metabolic status of various tissues. Several foods and consumption patterns have been associated with various cancers and approximately 30-35% of the cancer cases are correlated with overnutrition or malnutrition. However, several contradictory studies are available regarding the association between diet and cancer risk, which remains to be elucidated. Concurrently, oxidative stress is a crucial factor for cancer progression and therapy. Nutritional oxidative stress may be induced by an imbalance between antioxidant defense and pro-oxidant load due to inadequate or excess nutrient supply. Oxidative stress is a physiological state where high levels of reactive oxygen species (ROS) and free radicals are generated. Several signaling pathways associated with carcinogenesis can additionally control ROS generation and regulate ROS downstream mechanisms, which could have potential implications in anticancer research. Cancer initiation may be modulated by the nutrition-mediated elevation in ROS levels, which can stimulate cancer initiation by triggering DNA mutations, damage, and pro-oncogenic signaling. Therefore, in this review, we have provided an overview of the relationship between nutrition, oxidative stress, and cancer initiation, and evaluated the impact of nutrient-mediated regulation of antioxidant capability against cancer therapy.

Docosahexaenoic Acid Induces Oxidative DNA Damage and Apoptosis, and Enhances the Chemosensitivity of Cancer Cells

The human diet contains low amounts of ω-3 polyunsaturated fatty acids (PUFAs) and high amounts of ω-6 PUFAs, which has been reported to contribute to the incidence of cancer. Epidemiological studies have shown that a high consumption of fish oil or ω-3 PUFAs reduced the risk of colon, pancreatic, and endometrial cancers. The ω-3 PUFA, docosahexaenoic acid (DHA), shows anticancer activity by inducing apoptosis of some human cancer cells without toxicity against normal cells. DHA induces oxidative stress and oxidative DNA adduct formation by depleting intracellular glutathione (GSH) and decreasing the mitochondrial function of cancer cells. Oxidative DNA damage and DNA strand breaks activate DNA damage responses to repair the damaged DNA. However, excessive DNA damage beyond the capacity of the DNA repair processes may initiate apoptotic signaling pathways and cell cycle arrest in cancer cells. DHA shows a variable inhibitory effect on cancer cell growth depending on the cells’ molecular properties and degree of malignancy. It has been shown to affect DNA repair processes including DNA-dependent protein kinases and mismatch repair in cancer cells. Moreover, DHA enhanced the efficacy of anticancer drugs by increasing drug uptake and suppressing survival pathways in cancer cells. In this review, DHA-induced oxidative DNA damage, apoptotic signaling, and enhancement of chemosensitivity in cancer cells will be discussed based on recent studies.