Biomarkers of dietary fatty acid intake and the risk of breast cancer: a meta-analysis

Red Blood Cell Polyunsaturated Fatty Acids and Mortality Following Breast Cancer

BACKGROUND

Intake of polyunsaturated fatty acids (PUFA) may affect mortality following breast cancer; however, epidemiological studies have relied on the self-reported assessment of PUFA intake. Herein, we examined the associations between red blood cell (RBC) PUFAs and mortality.

METHODS

This nested case-control study included 1,104 women from the Women's Healthy Eating and Living study, a multistate randomized controlled trial. Cases (n = 290) comprised women who died from 1995 to 2006. Matched controls (n = 814) comprised women who were alive at the end of follow-up. PUFAs were measured in baseline RBC samples and included four ω-3 and seven ω-6 PUFAs. We examined each PUFA individually and principal components factor analysis (PCFA)-derived scores in association with all-cause mortality (ACM) and breast cancer-specific mortality (BCM) using conditional logistic regression to estimate ORs and 95% confidence intervals (CIs).

RESULTS

In fully adjusted models, ACM ORs were elevated among women with PUFAs above the median  (>median) versus at the median or below (≤median) for α-linolenic acid (ALA; OR = 1.63, 95% CI, 1.18-2.24) and linolenic acid (LA; OR = 1.56, 95% CI, 1.16-2.09). BCM ORs were elevated for ALA (OR = 1.83, 95% CI, 1.27-2.63), LA (OR = 1.70, 95% CI, 1.23-2.37), and γ-linolenic acid (GLA; OR = 1.50, 95% CI, 1.04-2.16). PCFA Factor 1 (arachidonic acid-adrenic acid-docosapentaenoic acid) scores above the median (vs. ≤median) were associated with lower odds of ACM (OR = 0.71, 95% CI, 0.52-0.97) and BCM (OR = 0.69, 95% CI, 0.49-0.97). PCFA Factor 4 (ALA/GLA) scores above the median (vs. ≤median) were associated with increased odds of BCM (OR = 1.47, 95% CI, 1.04-2.09).

CONCLUSIONS

RBC ALA, LA, and GLA may be prognostic indicators among breast cancer survivors.

IMPACT

These results are important for understanding the associations between a biomarker of PUFA intake and mortality among BC survivors.

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.

Obesity-induced changes in cancer cells and their microenvironment: Mechanisms and therapeutic perspectives to manage dysregulated lipid metabolism

Obesity has been closely related to cancer progression, recurrence, metastasis, and treatment resistance. We aim to review recent progress in the knowledge on the obese macroenvironment and the generated adipose tumor microenvironment (TME) inducing lipid metabolic dysregulation and their influence on carcinogenic processes. Visceral white adipose tissue expansion during obesity exerts systemic or macroenvironmental effects on tumor initiation, growth, and invasion by promoting inflammation, hyperinsulinemia, growth-factor release, and dyslipidemia. The dynamic relationship between cancer and stromal cells of the obese adipose TME is critical for cancer cell survival and proliferation as well. Experimental evidence shows that secreted paracrine signals from cancer cells can induce lipolysis in cancer-associated adipocytes, causing them to release free fatty acids and acquire a fibroblast-like phenotype. Such adipocyte delipidation and phenotypic change is accompanied by an increased secretion of cytokines by cancer-associated adipocytes and tumor-associated macrophages in the TME. Mechanistically, the availability of adipose TME free fatty acids and tumorigenic cytokines concomitant with the activation of angiogenic processes creates an environment that favors a shift in the cancer cells toward an aggressive phenotype associated with increased invasiveness. We conclude that restoring the aberrant metabolic alterations in the host macroenvironment and in adipose TME of obese subjects would be a therapeutic option to prevent cancer development. Several dietary, lipid-based, and oral antidiabetic pharmacological therapies could potentially prevent tumorigenic processes associated with the dysregulated lipid metabolism closely linked to obesity.

The Effects of Omega-3 Polyunsaturated Fatty Acids on Breast Cancer as a Preventive Measure or as an Adjunct to Conventional Treatments

In order to understand how omega-3 polyunsaturated fatty acid (ω-3 PUFA) supplements affect breast cancer prevention and treatment, a systematic review of articles published in the last 5 years in two databases was performed. Of the 679 articles identified, only 27 were included and examined based on five topics, taking into account: the induction type of the breast cancer used in animal models; the characteristics of the induction model by cell transplantation; the experimental design of the ω-3 supplementation—combined or not with a treatment antitumor drug; the fatty acids (FAs) composition used; the analysis of the studies’ outcomes. There are diverse and well-established animal models of breast cancer in the literature, with very relevant histological and molecular similarities depending on the specific objective of the study, such as whether the method of tumor induction was transgenic, by cell transplantation, or by oncogenic drugs. The analyses of outcomes were mainly focused on monitoring tumor growth, body/tumor weight, and molecular, genetic, or histological analyses, and few studies evaluated latency, survival, or metastases. The best results occurred when supplementation with ω-3 PUFA was associated with antitumor drugs, especially in the analysis of metastases and volume/weight of tumors or when the supplementation was started early and maintained for a long time. However, the beneficial effect of ω-3 PUFA supplementation when not associated with an antitumor agent remains unclear.

Breast cancer and dietary fat quality indices in Iranian women: A case-control study

Background

The association between breast cancer (BC) and different indices of dietary fats has not been well-studied. Thus, this study aimed to investigate the association between BC and dietary fat quality (DFQ) indices in Iranian women.

Methods

This case-control study was conducted on 120 women with breast cancer and 240 healthy women in Tehran, Iran. Food Frequency Questionnaire and nutritionist IV software were used to assess the intake of dietary fats and to calculate the DFQ indices.

Results

The patients with BC had a higher total fat (TF) (P < 0.01) and a lower ratio of polyunsaturated fatty acids (PUFAs) omega-3 to PUFAs omega-6 (ω-3/ω-6) compared with the controls (P < 0.001). TF had a significant association with BC risk (OR: 1.16; 95% CI: 1.01-1.33, P < 0.001). No significant association was found between BC and PUFA/saturated fatty acid ratio or the ω-3/ω-6 ratio.

Conclusion

The patients with BC had a lower ω-3/ω-6 ratio and a higher total dietary fat intake than the healthy women. Total dietary fat intake was also directly associated with the risk of BC. Thus, low-fat diets may have beneficial effects for BC prevention. Further longitudinal studies are warranted.

The Modulatory Effects of Fatty Acids on Cancer Progression

Cancer is the second leading cause of death worldwide and the global cancer burden rises rapidly. The risk factors for cancer development can often be attributed to lifestyle factors, of which an unhealthy diet is a major contributor. Dietary fat is an important macronutrient and therefore a crucial part of a well-balanced and healthy diet, but it is still unclear which specific fatty acids contribute to a healthy and well-balanced diet in the context of cancer risk and prognosis. In this review, we describe epidemiological evidence on the associations between the intake of different classes of fatty acids and the risk of developing cancer, and we provide preclinical evidence on how specific fatty acids can act on tumor cells, thereby modulating tumor progression and metastasis. Moreover, the pro- and anti-inflammatory effects of each of the different groups of fatty acids will be discussed specifically in the context of inflammation-induced cancer progression and we will highlight challenges as well as opportunities for successful application of fatty acid tailored nutritional interventions in the clinic.

Diet, lipids, and antitumor immunity

Tumour growth and dissemination is largely dependent on nutrient availability. It has recently emerged that the tumour microenvironment is rich in a diverse array of lipids that increase in abundance with tumour progression and play a role in promoting tumour growth and metastasis. Here, we describe the pro-tumorigenic roles of lipid uptake, metabolism and synthesis and detail the therapeutic potential of targeting lipid metabolism in cancer. Additionally, we highlight new insights into the distinct immunosuppressive effects of lipids in the tumour microenvironment. Lipids threaten an anti-tumour environment whereby metabolic adaptation to lipid metabolism is linked to immune dysfunction. Finally, we describe the differential effects of commondietary lipids on cancer growth which may uncover a role for specific dietary regimens in association with traditional cancer therapies. Understanding the relationship between dietary lipids, tumour, and immune cells is important in the context of obesity which may reveal a possibility to harness the diet in the treatment of cancers.

C/EBPB-dependent adaptation to palmitic acid promotes tumor formation in hormone receptor negative breast cancer

Epidemiological studies have established a positive association between obesity and the incidence of postmenopausal breast cancer. Moreover, it is known that obesity promotes stem cell-like properties of breast cancer cells. However, the cancer cell-autonomous mechanisms underlying this correlation are not well defined. Here we demonstrate that obesity-associated tumor formation is driven by cellular adaptation rather than expansion of pre-existing clones within the cancer cell population. While there is no correlation with specific mutations, cellular adaptation to obesity is governed by palmitic acid (PA) and leads to enhanced tumor formation capacity of breast cancer cells. This process is governed epigenetically through increased chromatin occupancy of the transcription factor CCAAT/enhancer-binding protein beta (C/EBPB). Obesity-induced epigenetic activation of C/EBPB regulates cancer stem-like properties by modulating the expression of key downstream regulators including CLDN1 and LCN2. Collectively, our findings demonstrate that obesity drives cellular adaptation to PA drives tumor initiation in the obese setting through activation of a C/EBPB dependent transcriptional network.

Obesity is linked to cancer risk in post-menopausal breast cancer. At the molecular level this is governed by cellular adaption to palmitic acid through epigenetic activation of a C/EBPB-dependent transcriptional network that drives tumor formation.

Association between dietary fat and fat subtypes with the risk of breast cancer in an Iranian population: a case-control study

AIM

To examine the relationship between dietary fat intake and breast cancer (BC) development.

METHOD

This case-control study included 473 women with breast cancer (pathologically confirmed) and 501 healthy subjects matched by age and residency. Dietary intakes of different types and sources of fatty acids were assessed using a validated food frequency questionnaire. The association between dietary fats and odds of BC was assessed using a logistic regression model in crude and multivariable-adjusted models. P values below 0.05 were regarded as statistically significant.

RESULTS

Participants' age and body mass index were 44.0 ± 10.8 years and 28.4 ± 5.6 kg/m2, respectively. Individuals with the highest quartile of total fat intake and polyunsaturated fatty acid (PUFA) intake were 1.50 times more at risk to develop BC than others. A positive significant association was observed between animal fat (Q4 vs. Q1, OR = 1.89, 95 % CI = 0.93-3.81), saturated fatty acid (SFA) (Q4 vs. Q1, OR = 1.70, 95 % CI = 0.88-3.30), monounsaturated fatty acid (MUFA) (Q4 vs. Q1 OR = 1.85, 95 % CI = 0.95-3.61) and PUFA intake (Q4 vs. Q1, OR = 2.12, 95 % CI = 1.05-4.27) with BC risk in postmenopausal women. However, there was no association in premenopausal women.

CONCLUSIONS

Total dietary fat and its subtypes might increase the risk of BC, especially in postmenopausal women. This observational study confirms the role of dietary fat in breast cancer development. Intervention studies involving different estrogen receptor subgroups are needed.

Physiological extremes of the human blood metabolome: A metabolomics analysis of highly glycolytic, oxidative, and anabolic athletes

Human metabolism is highly variable. At one end of the spectrum, defects of enzymes, transporters, and metabolic regulation result in metabolic diseases such as diabetes mellitus or inborn errors of metabolism. At the other end of the spectrum, favorable genetics and years of training combine to result in physiologically extreme forms of metabolism in athletes. Here, we investigated how the highly glycolytic metabolism of sprinters, highly oxidative metabolism of endurance athletes, and highly anabolic metabolism of natural bodybuilders affect their serum metabolome at rest and after a bout of exercise to exhaustion. We used targeted mass spectrometry-based metabolomics to measure the serum concentrations of 151 metabolites and 43 metabolite ratios or sums in 15 competitive male athletes (6 endurance athletes, 5 sprinters, and 4 natural bodybuilders) and 4 untrained control subjects at fasted rest and 5 minutes after a maximum graded bicycle test to exhaustion. The analysis of all 194 metabolite concentrations, ratios and sums revealed that natural bodybuilders and endurance athletes had overall different metabolite profiles, whereas sprinters and untrained controls were more similar. Specifically, natural bodybuilders had 1.5 to 1.8-fold higher concentrations of specific phosphatidylcholines and lower levels of branched chain amino acids than all other subjects. Endurance athletes had 1.4-fold higher levels of a metabolite ratio showing the activity of carnitine-palmitoyl-transferase I and 1.4-fold lower levels of various alkyl-acyl-phosphatidylcholines. When we compared the effect of exercise between groups, endurance athletes showed 1.3-fold higher increases of hexose and of tetradecenoylcarnitine (C14:1). In summary, physiologically extreme metabolic capacities of endurance athletes and natural bodybuilders are associated with unique blood metabolite concentrations, ratios, and sums at rest and after exercise. Our results suggest that long-term specific training, along with genetics and other athlete-specific factors systematically change metabolite concentrations at rest and after exercise.

Serum fatty acid synthase levels and n-3 fatty acid intake in patients with breast cancer

PURPOSE

Fatty acid synthase (FASN) is a key enzyme in fatty acid biosynthesis that is usually over-expressed in patients with breast cancer, but its relationship with the patient's dietary habit is not clear. A higher intake of n-3 polyunsaturated fatty acids is related to reduced breast carcinogenesis in vitro and in vivo. The aim of this study was to clinically investigate the association between serum FASN levels and fatty acid intake in women newly diagnosed with breast cancer.

METHODS

In a case-control cross-sectional study, with 18 breast cancer patients and 29 controls, we evaluated nutritional status, dietary intake, and serum FASN levels. Statistical analyses were carried out with parametric and non-parametric tests, according to the sample's normality distribution.

RESULTS

The mean age of breast cancer group (n = 18) and control group (n = 29) was 46.8 ± 9.7 y and 44.4. ± 8.6 y, respectively. Mean serum concentration of FASN in breast cancer group was significantly higher (132.51 ± 95.05 ng/mL) than in control group (36.88 ± 20.87 ng/mL) (p < 0.0001). Among breast cancer group, serum FASN levels of premenopausal women were significantly higher than those of postmenopausal women (p = 0.026). There was no significant difference between the early and late disease stages in regard to serum FASN levels in breast cancer group. Mean nutrient intake was similar and n-3 docosahexaenoic acid intake was low in both groups. We observed no association regarding fatty acid intake and serum FASN levels.

CONCLUSION

These data suggest that dietary n-3 fatty acid has no association with serum FASN levels among newly diagnosed breast cancer patients.

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.

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.

Plasma omega-3 polyunsaturated fatty acids and recurrence of endometrial cancer

BACKGROUND

Omega-3 polyunsaturated fatty acids (PUFAs) were proposed to have potential effects against inflammation and cancer. However, results from epidemiology studies remain inconsistent. We aimed to explore the associations of plasma PUFAs with EC recurrence and all-cause mortality.

METHOD

Women diagnosed with endometrial cancer (EC) between 2008 and 2013 and underwent surgery at Fudan University Shanghai Cancer Center of China were recruited. Survival status was followed up through September 2017. EC recurrence and total cause deaths were identified through medical record and telephone interview. In total, 202 patients with enough plasma samples at time of surgery were included. There were 195 patients who provided baseline plasma and survival information included in the current study. Plasma omega-3 PUFAs were measured by GC-FID. Cox Proportional Hazard model adjusted for potential cofounders was used to estimate HRs and 95% CIs.

RESULTS

Median follow-up time for patients was 58 months after surgery. A total of 13 recurrences and 11 all-cause deaths, of which, 2 deaths from EC, were identified. Level of plasma EPA was higher in recurrent patients than total patients (0.78% vs 0.51%, P = 0.015). Higher plasma eicosapentaenoic acid (EPA) level trended to have positive association with EC recurrence (P-trend = 0.04), although comparing to the lowest tertile, the highest tertile of EPA level was not significantly associated with increased risk of EC recurrence (HRT3vsT1 = 6.02; 95%CI = 0.7-52.06). The association between total omega-3 PUFA and EC recurrence tended to be stronger among patients with deeper myometrial invasion (OR = 3.41; 95%CI = 1.06-10.95; P-interaction = 0.04).

CONCLUSIONS

Higher plasma EPA level was significantly associated with EC recurrence. Further studies are warranted to confirm these findings.

TRIAL REGISTRATION

ChiCTR1900025418; Retrospectively registered (26 August 2019); Chinses Clinical Trial Registry.

The Intake of Some Nutrients is Associated with the Risk of Breast Cancer: Results from Jordanian Case-Control Study

Breast cancer (BC) is the most commonly diagnosed cancer and is considered the leading cause of cancer deaths in women globally. The aim of this study is to evaluate the relationship between macro- and micronutrient intake and BC risk among Jordanian women. A case-control design was used in this study, and BC patients were recruited from the main two hospitals provide cancer therapy in Jordan. Four hundred women aged 20-65 years of age were enrolled in the study. For the cases, 200 recently diagnosed BC women were selected from the two hospitals and matched in age and marital status to 200 BC-free women. Dietary data were collected through face-to-face interview using a validated food frequency questionnaire between October 2016 and September 2017. To calculate odds ratio (OR), logistic regression was used; while for p-trend the linear regression was performed. The study results demonstrated that increasing the intake of total energy and percentage of fat was significantly and positively associated with BC (p-= 0.001). The risk of BC increased significantly and positively as carbohydrate, sugar, fat, saturated fat and polyunsaturated and monounsaturated fatty acids intake increased. A significant trend in BC risk was found for cholesterol (p-= 0.005). The ORs for higher intakes of vitamins E, B1, B2, and B3, folate and phosphorus showed a significant association with the risk of BC (p-trend =0.001). A significant inverse effect was detected between iron intake and BC risk (p-=0.001). The study findings resulted in insight of the associations between the total energy intake and some macro/micronutrients intake can be an increasing risk of BC.

Metabolomics in endometrial cancer diagnosis: A systematic review

INTRODUCTION

Endometrial cancer (EC) is the most common gynecological malignancy in the developed world. The prognosis of EC strongly depends on tumor stage, hence the importance of improving diagnosis. Metabolomics has recently appeared as a promising test for a non-invasive diagnosis of several diseases. Nevertheless, no metabolic marker has been approved for use in the routine practice. We aimed to provide an overview of metabolomics findings in the diagnosis of EC.

MATERIAL AND METHODS

A systematic review was performed by searching eight electronic databases from their inception to October 2019 for studies assessing metabolomics in EC diagnosis. Extracted data included characteristics of patients and EC, serum concentration of metabolites in women with and without EC and its association with EC diagnosis, tumor behavior and pathological characteristics.

RESULTS

Six studies with 732 women (356 cases and 376 controls) were included. Several metabolites were found able to predict the presence of EC, tumor behavior (progression and recurrence) and pathological characteristics (histotype, myometrial invasion and lymph vascular space invasion).

CONCLUSIONS

Metabolomics might be suitable for a non-invasive diagnosis and screening of EC, offering the possibility to predict tumor behavior and pathological characteristics. Further studies are necessary to validate these results.

Pubertal mammary development as a "susceptibility window" for breast cancer disparity

Factors such as socioeconomic status, age at menarche and childbearing patterns are components that have been shown to influence mammary gland development and establish breast cancer disparity. Pubertal mammary gland development is selected as the focus of this review, as it is identified as a "window of susceptibility" for breast cancer risk and disparity. Here we recognize non-Hispanic White, African American, and Asian American women as the focus of breast cancer disparity, in conjunction with diets associated with changes in breast cancer risk. Diets consisting of high fat, N-3 polyunsaturated fatty acids, N-6 polyunsaturated fatty acids, as well as obesity and the Western diet have shown to lead to changes in pubertal mammary gland development in mammalian models, therefore increasing the risk of breast cancer and breast cancer disparity. While limited intervention strategies are offered to adolescents to mitigate development changes and breast cancer risk, the prominent solution to closing the disparity among the selected population is to foster lifestyle changes that avoid the deleterious effects of unhealthy diets.

Evaluation of long-chain acyl-coenzyme A synthetase 4 (ACSL4) expression in human breast cancer

Background and purpose:

Breast cancer (BC) is one of the major causes of female cancer-related death. It has recently been demonstrated that metabolic reprogramming including alteration in lipid metabolism is indicated in various types of cancer. The enzymes of the acyl-coenzyme A synthetase long-chain family (ACSLs) are responsible for converting fatty acids to their corresponding fatty acyl-coenzyme A esters which are essential for some lipid metabolism pathways. ACSL4 is one of the isoforms of ACSLs and has a marked preference for arachidonic and eicosapentaenoic acids. The objective of this study was to evaluate ACSL4 expression, its prognostic significance, and its correlation with p53 tumor suppressor in BC patients.

Experimental approach:

In this study 55 pairs of fresh samples of BC and adjacent non-cancerous tissue were used to analyze ACSL4 expression, using real-time polymerase chain reaction and immunohistochemistry (IHC) staining. The expression of other studied variables was also examined using the IHC technique.

Findings / Results:

ACSL4 expression was significantly higher in BC tissues compared to the adjacent normal tissue. This upregulation was negatively correlated with Ki-67 and age, and positively correlated with p53 status. The correlation between ACSL4 and p53 may indicate the role of p53 in the regulation of lipid metabolism in cancer cells, in addition to its role in the regulation of ferroptosis cell death.

Conclusion and implications:

Our results indicated that the expression of ACSL4 may be considered as a prognostic indicator and potential therapeutic target in BC. However, further studies are needed to confirm the significance of these findings.

Total Dietary Fats, Fatty Acids, and Omega-3/Omega-6 Ratio as Risk Factors of Breast Cancer in the Polish Population - a Case-Control Study

BACKGROUND/AIM

Breast cancer is the most common type of cancer among women around the world and the leading cause of cancer-related death among women. The knowledge about modifiable risk factors, such as diet, can be an acceptable, cheap and non-pharmacological prevention tool. The aim of this study was to investigate the association between dietary fat, dietary fatty acids, fish intake, and breast cancer in women.

PATIENTS AND METHODS

A case-control study was designed. A total of 201 consecutive, newly diagnosed, polish female cancer patients (mean age: 58 years) and 201 one-to-one age-matched controls were enrolled. A standardised questionnaire assessing various socio-demographic, clinical, lifestyle, and dietary characteristics was applied via face-to-face interviews. Detailed dietary intake information was assessed using a validated Food Frequency Questionnaire. Odds ratios (OR) and 95% confidence intervals (95%CI) were obtained using multiple unconditional logistic regression models controlling for non-dietary and dietary potential confounders.

RESULTS

Consumption of polyunsaturated fats (PUFA) over 10% of total energy intake was associated with a significantly lower risk of breast cancer compared to low intake of PUFA (OR=0.4, 95%CI=0.19-0.85). Low (<0.2) omega-3/ omega-6 ratio (OR=2.04, 95%CI=0.996-4.17), fish consumption less than once every six months (OR=3.37, 95%CI=1.57-7.23) and being overweight (OR=2.07, 95%CI=1.3-3.3) were associated with increased risk of breast cancer. Residents of rural areas had a significantly higher risk compared to women from urban areas (OR=1.8, 95%CI=1.06-3.03).

CONCLUSION

High intake of PUFA can decrease the risk of breast cancer, while the low omega-3/omega-6 ratio increases the risk. In addition, overweight state, eliminating fish from the diet and living in rural areas can also increase the risk of breast cancer.

Fatty acid profiles in erythrocyte membranes following the Mediterranean diet - data from a multicenter lifestyle intervention study in women with hereditary breast cancer (LIBRE)

BACKGROUND & AIMS

Evidence-based concepts to prevent breast cancer in women with BRCA1/2 mutations are limited. Adherence to a Mediterranean diet (MedD) has been associated with a lower risk for breast cancer, possibly due to a favorable fatty acid (FA) intake. Here, we studied in an at-risk population the effect of a lifestyle intervention that included the MedD on FA composition in red blood cell membranes (RBCM).

METHODS

Data derived from the German multicenter trial LIBRE, from which 68 women were randomized into an intervention group (IG) trained for MedD and increased physical activity for 12 months, and a usual care control group (CG). Adherence to the diet was assessed after 3 and 12 months using the validated Mediterranean Diet Adherence Screener (MEDAS) and a food frequency questionnaire. RBCM FA were analyzed by gas chromatography with mass spectrometry.

RESULTS

The MEDAS was increased in both groups after 3 months (IG: P < 0.001; CG: P = 0.004), and remained increased only in the IG after 12 months (P < 0.001). The food frequency questionnaire revealed an increased intake of omega-3 (n-3) FA at month 3 and month 12 in the IG (both P < 0.01), but not in the CG, in which intake of energy, protein and saturated FA decreased. In both groups n-6 FA in the RBCM decreased (P < 0.001), while n-9 FA increased (P < 0.001) and n-3 FA were unchanged. Women with higher consumption of fish had higher amounts of n-3 fatty acids in the RBCM. The MEDAS was inversely correlated with n-6 fatty acids.

CONCLUSIONS

The RBCM FA composition was associated with dietetic parameters related to the MedD. Adherence to the MedD resulted in an altered, likely favorable FA composition. Our data suggest selected FA as biomarkers to monitor compliance to a dietetic intervention such as the MedD.

CLINICAL TRIAL REGISTRY

The trial is registered at ClinicalTrials.gov (reference: NCT02087592).

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.

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.

When Is Enough, Enough? When Are More Observational Epidemiologic Studies Needed to Resolve a Research Question: Illustrations Using Biomarker-Cancer Associations

BACKGROUND

Research reproducibility is vital for translation of epidemiologic findings. However, repeated studies of the same question may be undertaken without enhancing existing knowledge. To identify settings in which additional research is or is not warranted, we adapted research synthesis metrics to determine number of additional observational studies needed to change the inference from an existing meta-analysis.

METHODS

The fail-safe number (FSN) estimates number of additional studies of average weight and null effect needed to drive a statistically significant meta-analysis to null (P ≥ 0.05). We used conditional power to determine number of additional studies of average weight and equivalent heterogeneity to achieve 80% power in an updated meta-analysis to detect the observed summary estimate as statistically significant. We applied these metrics to a curated set of 98 meta-analyses on biomarkers and cancer risk.

RESULTS

Both metrics were influenced by number of studies, heterogeneity, and summary estimate size in the existing meta-analysis. For the meta-analysis on Helicobacter pylori and gastric cancer with 15 studies [OR = 2.29; 95% confidence interval (CI), 1.71-3.05], FSN was 805 studies, supporting futility of further study. For the meta-analysis on dehydroepiandrosterone sulfate and prostate cancer with 7 studies (OR = 1.29; 95% CI, 0.99-1.69), 5 more studies would be needed for 80% power, suggesting further study could change inferences.

CONCLUSIONS

Along with traditional assessments, these metrics could be used by stakeholders to decide whether additional studies addressing the same question are needed.

IMPACT

Systematic application of these metrics could lead to more judicious use of resources and acceleration from discovery to population-health impact.

Validation of repeated self-reported n-3 PUFA intake using serum phospholipid fatty acids as a biomarker in breast cancer patients during treatment

Background

The role of n-3 polyunsaturated fatty acids (PUFAs) in breast cancer is not clear and under debate. To explore this relationship it is important to have proper validated dietary assessment methods for measuring the intake of n-3 PUFAs. The aim of the current study is to validate two different methods used to assess the intake of selected n-3 PUFAs as well as food sources of long-chained n-3 PUFAs. Also, we aim to study how stable the intake of fatty acids is during breast cancer treatment.

Methods

The study-population was patients with breast cancer (Stages I-II) or ductal carcinoma in situ (DCIS-grade III) undergoing treatment (n = 49) in Norway. Dietary intake was assessed by two self-administered methods, a 256 food item food frequency questionnaire (FFQ) and a 7-day pre-coded food diary (PFD). The FFQ was administered presurgery and twelve months postsurgery, and the PFD was administered shortly after surgery (10 +/− 2 days), six and twelve months postsurgery. Fasting blood samples (presurgery, six and twelve months postsurgery) were analysed for serum phospholipid fatty acids, a biomarker for intake of n-3 PUFAs.

Results

Mean (SD) age was 54.2 (7.8) years at diagnosis, and the mean (SD) body mass index (BMI) was 24.8 (3.4) kg/m². Correlation coefficients between dietary intakes of n-3 PUFAs measured with the FFQ and the PFD ranged from 0.35 to 0.66. The correlation coefficients between the PFD and the biomarker (serum phospholipid n-3 PUFAs) as well as between the FFQ and the biomarker demonstrated stronger correlations twelve months after surgery (ρ 0.40–0.56 and 0.36–0.53, respectively) compared to around surgery (ρ 0.08–0.20 and 0.28–0.38, respectively). The same pattern was observed for intake of fatty fish. The intake of n-3 PUFAs did not change during treatment assessed by the FFQ, PFD or biomarker.

Conclusion

These results indicate that the FFQ and the PFD can be used to assess dietary intake of fish and n-3 PUFAs in breast cancer patients during breast cancer treatment. Still, the PFD shortly after surgery should be used with caution. The diet of patients undergoing breast cancer treatment was quite stable, and the intake of n-3 PUFAs did not change.

Electronic supplementary material

The online version of this article (10.1186/s12937-018-0402-6) contains supplementary material, which is available to authorized users.

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.

The role of free-fatty acid receptor-4 (FFA4) in human cancers and cancer cell lines

A dietary influence on cancer progression has been evident for many decades, and dietary fatty acids, particularly long chain mono- and polyunsaturated fatty acids, have been shown to play significant roles in influencing growth of a variety of human cancers. The discovery of the family of cell-surface free-fatty acid receptors, which include the long-chain fatty acid receptors FFA1 and FFA4, suggest that many of the effects of dietary fats could be receptor-mediated. FFA4 is ubiquitously expressed and has recently been shown to modulate a variety of important anti-inflammatory and metabolic processes. Since FFA4 is currently an attractive drug target for treatment of metabolic disorders such as diabetes and obesity, understanding its role in cancer progression is critical towards the drug discovery process. In this research update, the current body of knowledge on the role of this receptor in regulating cancer cell proliferation, migration, and invasion, as well as in vivo tumorigenesis is reviewed.

Erythrocyte Membrane Unsaturated (Mono and Poly) Fatty Acids Profile in Newly Diagnosed Basal Cell Carcinoma Patients

Studies have reported different changes in the fatty acid composition of red blood cell (RBC) total lipids in patients with various types of cancer. It has been indicated that n-3/n-6 ratio plays a key role in the general consequence of skin photocarcinogenesis. However, to our knowledge there was no study examining the unsaturated fatty acid profile in basal cell carcinoma (BCC) patients. So, we explore the fatty acid composition of RBCs in newly diagnosed BCC patients in a hospital-based case-control study. This study has been conducted on new case BCC patients in Razi Hospital, Tehran, Iran. Fatty acid concentration in erythrocyte membranes defined as relative values after extraction, purification and preparation, by gas chromatography.Analysis revealed that heptadecenoic acid (p = 0.010) and oleic acid (p < 0.001) was significantly higher in BCC patients in comparison with control group. Among polyunsaturated fatty acids (PUFAs), linoleic acid (LA), and arachidonic acid (AA) were significantly higher in BCC patients (p < 0.001). It has been indicated that n-3 was significantly lower (p = 0.040) and n-6 was significantly higher (p = 0.002) in BCC patients. In addition, total PUFA (p < 0.001) and n-6 PUFAs/n-3 PUFAs (p = 0.002) were significantly higher in BCC patients compared to the control group. Here we indicated that new case BCC patient had significantly higher n-6 PUFA and lower n-3 along with other differences in unsaturated fatty acid in comparison with healthy subjects. Our study provides evidence that lipids are important in BCC development.

Plant-Based Diet, Serum Fatty Acid Profile, and Free Radicals in Postmenopausal Women: The Diet and Androgens (DIANA) Randomized Trial

High calorie and fat consumption and the production of free radicals are two major mechanistic pathways between diet and disease. In this study we evaluated the effect of a plant-based diet poor in animal fat and rich in (n-3) fatty acids on fatty acids of serum phospholipids and on the production of reactive oxygen metabolites (ROMs). One hundred and four healthy female postmenopausal volunteers were recruited and randomized to a dietary intervention or a control group. Dietary intervention included a program of food education and biweekly common meals for 18 weeks. When the intervention and control groups were compared, it was seen that dietary intervention resulted in a significant reduction of saturated fatty acids (-1.5%) and a significant increase in (n-3) fatty acids (+20.6%), in particular docosahexaenoic acid (+24.8%). We observed that arachidonic acid decreased (–7.7%), while (n-6) fatty acids did not, and the (n-3)/(n-6) polyunsaturated ratio increased significantly (+24.1%). As expected, ROMs decreased significantly in the intervention group (-6%). The results indicated that a plant-based diet can improve the serum fatty acid profile and decrease ROMs production. These results suggest that a plant-based diet may reduce the body's exposure to oxidative stress.

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.

A role of low dose chemical mixtures in adipose tissue in carcinogenesis

The Halifax project recently hypothesized a composite carcinogenic potential of the mixture of low dose chemicals which are commonly encountered environmentally, yet which are not classified as human carcinogens. A long neglected but important fact is that adipose tissue is an important exposure source for chemical mixtures. In fact, findings from human studies based on several persistent organic pollutants in general populations with only background exposure should be interpreted from the viewpoint of chemical mixtures because serum concentrations of these chemicals can be seen as surrogates for chemical mixtures in adipose tissue. Furthermore, in conditions such as obesity with dysfunctional adipocytes or weight loss in which lipolysis is increased, the amount of the chemical mixture released from adipose tissue to circulation is increased. Thus, both obesity and weight loss can enhance the chance of chemical mixtures reaching critical organs, however paradoxical this idea may be when fat mass is the only factor considered. The complicated, interrelated dynamics of adipocytes and chemical mixtures can explain puzzling findings related to body weight among cancer patients, including the obesity paradox. The contamination of fat in human diet with chemical mixtures, occurring for reasons similar to contamination of human adipose tissue, may be a missing factor which affects the association between dietary fat intake and cancer. The presence of chemical mixtures in adipose tissue should be considered in future cancer research, including clinical trials on weight management among cancer survivors.

A prospective evaluation of plasma phospholipid fatty acids and breast cancer risk in the EPIC study

BACKGROUND

Intakes of specific fatty acids have been postulated to impact breast cancer risk but epidemiological data based on dietary questionnaires remain conflicting.

MATERIALS AND METHODS

We assessed the association between plasma phospholipid fatty acids and breast cancer risk in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition study. Sixty fatty acids were measured by gas chromatography in pre-diagnostic plasma phospholipids from 2982 incident breast cancer cases matched to 2982 controls. Conditional logistic regression models were used to estimate relative risk of breast cancer by fatty acid level. The false discovery rate (q values) was computed to control for multiple comparisons. Subgroup analyses were carried out by estrogen receptor (ER) and progesterone receptor expression in the tumours.

RESULTS

A high level of palmitoleic acid [odds ratio (OR) for the highest quartile compared with the lowest OR (Q4-Q1) 1.37; 95% confidence interval (CI), 1.14-1.64; P for trend = 0.0001, q value = 0.004] as well as a high desaturation index (DI16) (16:1n-7/16:0) [OR (Q4-Q1), 1.28; 95% C, 1.07-1.54; P for trend = 0.002, q value = 0.037], as biomarkers of de novo lipogenesis, were significantly associated with increased risk of breast cancer. Levels of industrial trans-fatty acids were positively associated with ER-negative tumours [OR for the highest tertile compared with the lowest (T3-T1)=2.01; 95% CI, 1.03-3.90; P for trend = 0.047], whereas no association was found for ER-positive tumours (P-heterogeneity =0.01). No significant association was found between n-3 polyunsaturated fatty acids and breast cancer risk, overall or by hormonal receptor.

CONCLUSION

These findings suggest that increased de novo lipogenesis, acting through increased synthesis of palmitoleic acid, could be a relevant metabolic pathway for breast tumourigenesis. Dietary trans-fatty acids derived from industrial processes may specifically increase ER-negative breast cancer risk.

Radiotherapy improves serum fatty acids and lipid profile in breast cancer

Background

Breast cancer is a disease with diverse clinical symptoms, molecular profiles, and its nature to response its therapeutic treatments. Radiotherapy (RT), along with surgery and chemotherapy is a part of treatment in breast cancer. The aim of present study was to investigate pre and post treatment effects of radiotherapy in serum fatty acids and its lipids profile in patients with breast cancer.

Methods

In this comparative as well as follow up study, Serum fatty acids were performed by gas chromatography to investigate fatty acids and Microlab for analysis of lipid profile.

Results

Among serum free and total fatty acids the major saturated fatty acids (SFAs) in serum lipids of breast cancer patients (pre and post treated) were stearic acid (18:0) and palmitic acid (16:0). These fatty acids contributed about 35-50% of total fatty acids. The decreased concentrations of linoleic acid (C18:2) and arachidonic acid (C20:4) with a lower ratio of C18:2/C18:1 was found in pretreated breast cancer patients as compared to controls. The n-3/n-6 ratio of breast cancer patients was decreased before treatment but it was 35% increased after treatment. In addition, plasma activity of D6 desaturase was increased in the breast cancer patients, while the activity of D5 desaturase was decreased. Increased levels of SFAs, monounsaturated fatty acids (MUFAs) and decreased polyunsaturated fatty acids (PUFAs) levels in breast cancer patients (pre and post treated) as compared to controls. Serum total cholesterol (TC) (224.4 mg/dL) and low density lipoprotein cholesterol (LDL-C) (142.9 mg/dL) were significantly increased in pretreated breast cancer patients but after the radiotherapy treatment, the TC (150.2 mg/dL) and LDL-C (89.8 mg/dL) were decreased.

Conclusion

It seems that RT would have played a potential role in the treatment of BC. After RT the serum levels of PUFAs, TC, and LDL-C are improved. Our study reinforces the important role of RT in the management of BC.

The level of PUFAs, TC, and LDL-C can be used as the biomarkers for early diagnosis in individuals with risk of breast cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-017-0481-y) contains supplementary material, which is available to authorized users.

Aberrant Phosphorylation of SMAD4 Thr277-Mediated USP9x-SMAD4 Interaction by Free Fatty Acids Promotes Breast Cancer Metastasis

Obesity increases the risk of distant metastatic recurrence and reduces breast cancer survival. However, the mechanisms behind this pathology and identification of relevant therapeutic targets are poorly defined. Plasma free fatty acids (FFA) levels are elevated in obese individuals. Here we report that TGFβ transiently activates ERK and subsequently phosphorylates SMAD4 at Thr277, which facilitates a SMAD4-USP9x interaction, SMAD4 nuclear retention, and stimulates TGFβ/SMAD3-mediated transcription of Twist and Snail. USP9x inhibited the E3 ubiquitin-protein ligase TIF1γ from binding and monoubiquitinating SMAD4, hence maintaining the SMAD4 nuclear retention. FFA further facilitated TGFβ-induced ERK activation, SMAD4 phosphorylation, and nuclear retention, promoting TGFβ-dependent cancer progression. Inhibition of ERK and USP9x suppressed obesity-induced metastasis. In addition, clinical data indicated that phospho-ERK and -SMAD4 levels correlate with activated TGFβ signaling and metastasis in overweight/obese patient breast cancer specimens. Altogether, we demonstrate the vital interaction of USP9x and SMAD4 for governing TGFβ signaling and dyslipidemia-induced aberrant TGFβ activation during breast cancer metastasis. Cancer Res; 77(6); 1383-94. ©2017 AACR.

Obesity and Breast Cancer: Current Insights on the Role of Fatty Acids and Lipid Metabolism in Promoting Breast Cancer Growth and Progression

Obesity and excess accumulation of adipose tissue are known risk factors for several types of cancer, including breast cancer. With the incidence of obesity constantly rising worldwide, understanding the molecular details of the interaction between adipose tissue and breast tumors, the most common tumors in women, becomes an urgent task. In terms of lipid metabolism, most of the studies conducted so far focused on upregulated de novo lipid synthesis in cancer cells. More recently, the use of extracellular lipids as source of energy came into focus. Especially in obesity, associated dysfunctional adipose tissue releases increased amounts of fatty acids, but also dietary lipids can be involved in promoting tumor growth and progression. In addition, it was shown that breast cancer cells and adipocytes, which are a major component of the stroma of breast tumors, are able to directly interact with each other. Breast cancer cells and adjacent adipocytes exchange molecules such as growth factors, chemokines, and interleukins in a reciprocal manner. Moreover, it was shown that breast cancer cells can access and utilize fatty acids produced by neighboring adipocytes. Thus adipocytes, and especially hypertrophic adipocytes, can act as providers of lipids, which can be used as a source of energy for fatty acid oxidation and as building blocks for tumor cell growth.

Propolis from the Stingless Bee Trigona incisa from East Kalimantan, Indonesia, Induces In Vitro Cytotoxicity and Apoptosis in Cancer Cell lines

BACKGROUND

Previously, stingless bee (Trigona spp.) products from East Kalimantan, Indonesia, were successfully screened for in vitro antiproliferative activity against human cancer derived cell lines. It was established that propolis from T. incisa presented the highest in vitro cytotoxicity against the SW620 colon cancer cell line (6% cell survival in 20 μg/mL).

MATERIALS AND METHODS

Propolis from T. incisa was extracted with methanol and further partitioned with n-hexane, ethyl acetate and methanol. The in vitro cytotoxicity of the extracts was assessed by the MTT assay against human colon (SW620), liver (Hep-G2), gastric (KATO-III), lung (Chago) and breast (BT474) cancer derived cell lines. The active fractions were further enriched by silica gel quick column, absorption and size exclusion chromatography. The purity of each fraction was checked by thin layer chromatography. Cytotoxicity in BT-474 cells induced by cardanol compared to doxorubicin were evaluated by MTT assay, induction of cell cycle arrest and cell death by flow cytometric analysis of propidium iodide and annexin-V stained cells.

RESULTS

A cardol isomer was found to be the major compound in one active fraction (F45) of T. incisa propolis, with a cytotoxicity against the SW620 (IC50 of 4.51±0.76 μg/mL), KATO-III (IC50 of 6.06±0.39 μg/mL), Hep-G2 (IC50 of 0.71±0.22 μg/mL), Chago I (IC50 of 0.81±0.18 μg/mL) and BT474 (IC50 of 4.28±0.14 μg/mL) cell lines. Early apoptosis (programmed cell death) of SW620 cells was induced by the cardol containing F45 fraction at the IC50 and IC80 concentrations, respectively, within 2-6 h of incubation. In addition, the F45 fraction induced cell cycle arrest at the G1 subphase.

CONCLUSIONS

Indonesian stingless bee (T. incisa) propolis had moderately potent in vitro anticancer activity on human cancer derived cell lines. Cardol or 5-pentadecyl resorcinol was identified as a major active compound and induced apoptosis in SW620 cells in an early period (≤6 h) and cell cycle arrest at the G1 subphase. Thus, cardol is a potential candidate for cancer chemotherapy.

Breast Cancer Genetic and Molecular Subtype Impacts Response to Omega-3 Fatty Acid Ethyl Esters

Epidemiological studies have correlated frequent omega-3 (n-3) fatty acid consumption with a lower risk for breast cancer; however, recent prospective studies have been less conclusive. Efforts in the preventive setting have focused on the use of n-3 fatty acids, and the pharmaceutical ethyl esters (EE) of these natural compounds, for high-risk patient populations. Limited understanding of specific mechanisms by which these agents function has hampered identification of the cancer subtype(s) that would gain the greatest therapeutic benefit. In this study, we investigated the in vitro effects of n-3 EEs in four distinct breast cancer subtypes and explored how they affect not only breast cancer cell survival but also modulate the nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB) and peroxisome proliferator-activated receptor gamma signaling pathways. Similar to the high variance in response observed in human studies, we found that the effectiveness of n-3 EEs depends on the molecular characteristics of the MCF-7, CAMA-1, MDA-MB-231, and SKBR3 breast cancer cell lines and is closely associated with the suppression of NF-κB. These data strongly suggest that the use of n-3 fatty acids and their pharmaceutical ether esters in the prevention and therapeutic setting should be guided by specific tumor characteristics.

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

PURPOSE

This study prospectively investigates associations between fatty acids assessed in plasma phospholipids (PPL) and diet, and breast cancer risk, including subgroups defined by hormone receptor status.

METHODS

We performed a case-cohort analysis within the Melbourne Collaborative Cohort Study using a random sample of 2,021 women and 470 breast cancer cases. At baseline, fatty acids were assessed in PPL and estimated from diet using a 121-item food frequency questionnaire. Hazard ratios (HR) and 95 % confidence intervals (CI) were estimated using Cox regression.

RESULTS

Breast cancer risk was positively associated with %PPL saturated fatty acids (SFA); HRQ5vsQ1 = 1.64 (95 % CI 1.17-2.30); p trend = 0.004. Positive associations were found for ER+ or PR+ tumors for %PPL SFA and palmitic acid and for ER-/PR- tumors for %PPL n-6 polyunsaturated fatty acid (PUFA), TFA, TFA 16:1, and TFA 18:1n-7 (all p homogeneity <0.05). Breast cancer risk was inversely associated with dietary docosapentaenoic acid (DPA); HRQ5vsQ1 = 0.57 (95 % CI 0.40-0.82); p trend = 0.001 [with similar inverse associations observed for dietary docosahexaenoic (DHA) and eicosapentaenoic acid (EPA)] and positively associated with dietary n-6:n-3 PUFA. Inverse associations for ER-/PR- tumors were found for dietary dihomo-γ-linolenic acid (DGLA) for older women (p homogeneity = 0.04).

CONCLUSIONS

Breast cancer risk was positively associated with %PPL SFA and the ratio of dietary n-6 to n-3 PUFA and inversely associated with dietary long-chain n-3 PUFA intake. Some associations between fatty acids and breast cancer varied by age and tumor phenotype defined by hormone receptor status. Increased intake of fish and other foods rich in long-chain n-3 PUFAs and reduced n-6 PUFA intake might reduce breast cancer risk.

Marine-derived omega-3 fatty acids: fishing for clues for cancer prevention

Omega-3 fatty acids (FA) are polyunsaturated essential FA with anti-inflammatory properties. The most potent are the marine-derived eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which counteract the pro-inflammatory omega-6 FA. Americans take in an average of only 100 mg of EPA plus DHA per day resulting in a low omega-3:omega-6 intake ratio of 1:10 favoring inflammation. Cohort and/or case control studies suggest EPA and DHA are promising for breast, colon, and prostate cancer risk reduction. Mechanistic studies largely in preclinical models suggest EPA and DHA reduce synthesis of prostaglandin E2 and other inflammatory cytokines, decrease aromatase activity and proliferation, promote differentiation and apoptosis, and enhance insulin sensitivity. Animal models using 7% to 20% omega-3 added to chow are promising; however, this amount of omega-3 in a diet is unlikely to be acceptable to humans. The optimal EPA:DHA ratio or the lowest effective dose of EPA and DHA for cancer prevention is unclear, but it is likely to be more than 600 mg/day, which is six times the average American intake. Most phase II prevention trials use 1 to 3.3 g of EPA and DHA, which is safe and well tolerated. Two grams of EPA was associated with fewer polyps in individuals with familial adenomatous polyposis in a randomized, placebo-controlled trial. Identification of serum risk biomarkers modulated by EPA and DHA in healthy humans has remained elusive, but phase II prevention trials with tissue obtained for risk and response biomarkers are ongoing.

Effect of Docosahexaenoic Acid on Cell Cycle Pathways in Breast Cell Lines With Different Transformation Degree

n-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), abundant in fish, have been shown to affect development and progression of some types of cancer, including breast cancer. The aim of our study was to further analyze and clarify the effects of these nutrients on the molecular mechanisms underlying breast cancer. Following treatments with DHA we examined cell viability, death, cell cycle, and some molecular effects in breast cell lines with different transformation, phenotypic, and biochemical characteristics (MCF-10A, MCF-7, SK-BR-3, ZR-75-1). These investigations showed that DHA is able to affect cell viability, proliferation, and cell cycle progression in a different way in each assayed breast cell line. The activation of ERK1/2 and STAT3 pathways and the expression and/or activation of molecules involved in cell cycle regulation such as p21(Waf1/Cip1) and p53, are very differently regulated by DHA treatments in each cell model. DHA selectively: (i) arrests non tumoral MCF-10A breast cells in G0 /G1 cycle phase, activating p21(Waf1/Cip1) , and p53, (ii) induces to death highly transformed breast cells SK-BR-3, reducing ERK1/2 and STAT3 phosphorylation and (iii) only slightly affects each analyzed process in MCF-7 breast cell line with transformation degree lower than SK-BR-3 cells. These findings suggest a more relevant inhibitory role of DHA within early development and late progression of breast cancer cell transformation and a variable effect in the other phases, depending on individual molecular properties and degree of malignancy of each clinical case.

Biological and Nutritional Properties of Palm Oil and Palmitic Acid: Effects on Health

A growing body of evidence highlights the close association between nutrition and human health. Fat is an essential macronutrient, and vegetable oils, such as palm oil, are widely used in the food industry and highly represented in the human diet. Palmitic acid, a saturated fatty acid, is the principal constituent of refined palm oil. In the last few decades, controversial studies have reported potential unhealthy effects of palm oil due to the high palmitic acid content. In this review we provide a concise and comprehensive update on the functional role of palm oil and palmitic acid in the development of obesity, type 2 diabetes mellitus, cardiovascular diseases and cancer. The atherogenic potential of palmitic acid and its stereospecific position in triacylglycerols are also discussed.

Associations of erythrocyte ω-3 fatty acids with biomarkers of ω-3 fatty acids and inflammation in breast tissue

There is increasing evidence that chronic inflammation is associated with increased breast cancer risk. Long-chain omega-3 polyunsaturated fatty acids (LCω-3PUFA) may reduce circulating biomarkers of inflammation; however associations of blood LCω-3PUFA with breast tissue LCω-3PUFA and breast tissue biomarkers of inflammation are not well understood. We conducted a cross-sectional analysis of breast tissue and blood samples from n = 85 women with no history of breast cancer, who underwent breast reduction surgery. Fatty acids of erythrocytes and undissected breast tissues were analyzed by gas chromatography; C-reactive protein (CRP), interleukin (IL)-6 and IL-8 in plasma and tissue were measured by ELISA. Multivariable-adjusted regression models were used to estimate associations between erythrocyte LCω-3PUFA and breast tissue biomarkers. Women in the highest erythrocyte LCω-3PUFA tertile had LCω-3PUFA concentrations in the breast 73% (95% CI: 31-128%; p trend < 0.0001) higher than women in the lowest tertile. Associations for each individual LCω-3PUFA were similar in magnitude. No significant association was found for the shorter ω-3 PUFA, α-linolenic acid. Although compatible with no association, women in the highest tertile of erythrocyte eicosapentaenoic acid had a nonsignificant 32% (95% CI: -23 to 62%) reduced breast tissue CRP. No correlation was observed between erythrocyte ω-3 PUFA and tissue IL-6 or IL-8 concentrations. Our findings provide evidence that erythrocyte ω-3 fatty acids are valid measures of breast tissue concentrations, and limited evidence that inverse associations from prospective epidemiologic studies of blood LCω-3PUFA and breast cancer risk may be partly explained by reductions in breast tissue inflammation; however, these findings require replication.

Application of credibility ceilings probes the robustness of meta-analyses of biomarkers and cancer risk

OBJECTIVES

Meta-analyses of biomarkers often present spurious significant results and large effects. We applied sensitivity analyses with the use of credibility ceilings to assess whether and how the results of meta-analyses of biomarkers and cancer risk would change.

STUDY DESIGN AND SETTING

We evaluated 98 meta-analyses, 43 (44%) of which had nominally statistically significant results. We assumed that any single study cannot give more than a maximum certainty 100 - c% (c, credibility ceiling) that the effect estimate [odds ratio (OR)] exceeds 1 (null) or 1.2.

RESULTS

Nominal statistical significance was maintained for 21 (21%) meta-analyses, for c = 10% and OR >1, and these proportions changed to 7%, 3%, and 6% with ceilings of 20%, 30%, and 40%, respectively. For ceilings for OR >1.2, the respective proportions were 37%, 21%, 7%, and 3%. Seven meta-analyses on infectious agents retained statistical significance even with a high ceiling of c = 20% for OR >1.00. Meta-analyses without other hints of bias (large between-study heterogeneity, small-study effects, excess significance) were more likely to retain statistical significance than those that had such hints of bias.

CONCLUSION

Credibility ceilings may be helpful in meta-analyses of biomarkers to understand the robustness of the results to different levels of uncertainty.

The role of n-3 polyunsaturated fatty acids in the prevention and treatment of breast cancer

Breast cancer (BC) is the most common cancer among women worldwide. Dietary fatty acids, especially n-3 polyunsaturated fatty acids (PUFA), are believed to play a role in reducing BC risk. Evidence has shown that fish consumption or intake of long-chain n-3 PUFA, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are beneficial for inhibiting mammary carcinogenesis. The evidence regarding α-linolenic acid (ALA), however, remains equivocal. It is essential to clarify the relation between ALA and cancer since ALA is the principal source of n-3 PUFA in the Western diet and the conversion of ALA to EPA and DHA is not efficient in humans. In addition, the specific anticancer roles of individual n-3 PUFA, alone, have not yet been identified. Therefore, the present review evaluates ALA, EPA and DHA consumed individually as well as in n-3 PUFA mixtures. Also, their role in the prevention of BC and potential anticancer mechanisms of action are examined. Overall, this review suggests that each n-3 PUFA has promising anticancer effects and warrants further research.