The Combined Association of Modifiable Risk Factors with Breast Cancer Risk in the Women's Health Initiative

Adulthood dietary and lifestyle patterns and risk of breast cancer: Global Cancer Update Programme (CUP Global) systematic literature review

BACKGROUND

An increasing number of studies in recent years investigate various dietary and lifestyle patterns and associated breast cancer (BC) risk.

OBJECTIVES

This study aimed to comprehensively synthesize and grade the evidence on dietary and lifestyle patterns and BC risk.

METHODS

Databases were systematically searched up to 31 March, 2022, for evidence from randomised controlled trials and prospective cohort studies on adherence to a dietary pattern alone or in combination with lifestyle behaviors and incidence of or mortality from primary BC in adult females. Findings in all, premenopausal, and postmenopausal females were descriptively synthesized instead of meta-analyzed due to patterns heterogeneity. An independent Global Cancer Update Programme Expert Panel graded the strength of the evidence.

RESULTS

A total of 84 publications were included. Results for patterns reflecting both a healthy diet and lifestyle were more consistent than for patterns that included diet only. There was strong-probable evidence that a priori World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) and American Cancer Society (ACS) dietary and lifestyle scores may reduce BC risk in all and postmenopausal females, whereas in premenopausal females, less evidence was found contributing to limited-suggestive grade. There was also a limited-suggestive evidence that adherence to the Healthy Lifestyle Index and other diet and lifestyle scores may reduce BC risk in postmenopausal females; a posteriori Western/Meat/Alcohol dietary patterns may increase BC risk in postmenopausal females; and Prudent/Vegetarian/Mediterranean dietary patterns may reduce BC risk in all females. For the remaining patterns, evidence was graded as limited-no conclusions.

CONCLUSIONS

Advice to adopt combined aspects of a healthy diet and lifestyle according to WCRF/AICR and ACS scores, encouraging a healthy weight, physical activity, alcohol and smoking avoidance, and a healthy diet rich in fruits, vegetables, (whole)grains and cereals and discouraging red and processed meat, can be proposed to females to lower BC risk. This review was registered at PROSPERO as ID CRD42021270129 (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021270129) on 28 August, 2021, and further updated on 4 May, 2022, in order to extend the search period.

Alcoholic beverage consumption and female breast cancer risk: A systematic review and meta-analysis of prospective cohort studies

Alcohol consumption is an established cause of female breast cancer. This systematic review examines in detail the association between alcohol and female breast cancer overall and among the described subgroups, using all of the evidence to date. A systematic review of PubMed and Embase was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search included articles published up to November 15, 2023. Meta-analyses and regressions were performed for alcohol consumption of less than 1 standard drink (10 g of ethanol) per day and for a range of alcohol consumption categories in relation to breast cancer. Analyses by menopausal status, hormone receptor status, human epidermal growth factor receptor 2 status, and molecular subtype were performed. The search yielded 5645 publications, of which 23 publications of individual and pooled studies examined the association between overall alcohol consumption and breast cancer incidence. The meta-regression showed a positive association; relative risks (RR) of breast cancer were 1.05 (95% CI: 1.04, 1.06), 1.10 (95% CI: 1.08, 1.12), 1.18 (95% CI: 1.15, 1.21), and 1.22 (95% CI: 1.19, 1.25) for 0.5, 1, 2, and 3 standard drinks per day compared with nondrinking, respectively. A meta-analysis of nine studies indicated that for consumption of less than one standard drink per day, the RR estimate of breast cancer was 1.04 (95% CI: 1.01, 1.07) compared with nondrinking. Consumption of an additional 1 standard drink per day was associated with a higher risk of premenopausal (RR: 1.03 (95% CI: 1.01, 1.06)) and postmenopausal (RR: 1.10 (95% CI: 1.08, 1.12)) breast cancer. Alcohol consumption increases female breast cancer risk, even for women who consume one drink per day. Furthermore, alcohol consumption is associated with both pre- and postmenopausal breast cancer risk. These findings support evidence-based cancer prevention guidelines to reduce alcohol-related risks.

Long-Term High-Fat Diet Limits the Protective Effect of Spontaneous Physical Activity on Mammary Carcinogenesis

Breast cancer is influenced by factors such as diet, a sedentary lifestyle, obesity, and postmenopausal status, which are all linked to prolonged hormonal and inflammatory exposure. Physical activity offers protection against breast cancer by modulating hormones, immune responses, and oxidative defenses. This study aimed to assess how a prolonged high-fat diet (HFD) affects the effectiveness of physical activity in preventing and managing mammary tumorigenesis. Ovariectomised C57BL/6 mice were provided with an enriched environment to induce spontaneous physical activity while being fed HFD. After 44 days (short-term, ST HFD) or 88 days (long-term, LT HFD), syngenic EO771 cells were implanted into mammary glands, and tumour growth was monitored until sacrifice. Despite similar physical activity and food intake, the LT HFD group exhibited higher visceral adipose tissue mass and reduced skeletal muscle mass. In the tumour microenvironment, the LT HFD group showed decreased NK cells and TCD8+ cells, with a trend toward increased T regulatory cells, leading to a collapse of the T8/Treg ratio. Additionally, the LT HFD group displayed decreased tumour triglyceride content and altered enzyme activities indicative of oxidative stress. Prolonged exposure to HFD was associated with tumour growth despite elevated physical activity, promoting a tolerogenic tumour microenvironment. Future studies should explore inter-organ exchanges between tumour and tissues.

Individual and joint effect of socioeconomic status and lifestyle factors on cancer in Korea

BACKGROUND

There is limited evidence on the individual and joint effect of socioeconomic status (SES) and unhealthy lifestyle on cancer. Therefore, this study aimed to examine the effects of these factors on cancer incidence and mortality.

METHODS

In this population-based cohort study, income was used as the proxy of SES. A combined unhealthy lifestyle score was obtained using data on smoking, alcohol consumption, physical activity, and body mass index. Hazard ratios were estimated using a Cox proportional hazards model.

RESULTS

The study included data on 8,353,169 participants (median follow-up period, 17 years). Although the association between low income and cancer incidence varied depending on cancer type, low income consistently increased the risk of cancer-related death with a social gradient. Unhealthy behaviors increased the risk of cancer incidence and mortality, except for thyroid and breast cancer in women and prostate cancer in men. Compared with the wealthiest and healthiest individuals, the poorest and unhealthiest men and women showed 2.1-fold (2.05-2.14) and 1.36-fold (1.31-1.41) higher risk of cancer-related death, respectively. The joint effect was most robust for lung, liver, head, and neck cancers in men and liver and cervical cancers in women; further, the effect was stronger with cancer-specific mortality than with incidence.

CONCLUSION

In conclusion, income and combined healthy lifestyle behaviors have individual and joint effects on cancer incidence and mortality. The effect varies by cancer type and sex.

FGF/FGFR1 system in paired breast tumor-adjacent and tumor tissues, associations with mammographic breast density and tumor characteristics

Introduction

Mammographic breast density (MBD) is an established breast cancer risk factor, yet the underlying molecular mechanisms remain to be deciphered. Fibroblast growth factor receptor 1 (FGFR1) amplification is associated with breast cancer development and aberrant FGF signaling found in the biological processes related to both high mammographic density and breast cancer microenvironment. The aim of this study was to investigate the FGF/FGFR1 expression in-between paired tumor-adjacent and tumor tissues from the same patient, and its associations with MBD and tumor characteristics.

Methods

FGFR1 expression in paired tissues from 426 breast cancer patients participating in the Karolinska Mammography Project for Risk Prediction of Breast Cancer (KARMA) cohort study was analyzed by immunohistochemistry. FGF ligand expression was obtained from RNA-sequencing data for 327 of the included patients.

Results

FGFR1 levels were differently expressed in tumor-adjacent and tumor tissues, with increased FGFR1 levels detected in 58% of the tumors. High FGFR1 expression in tumor tissues was associated with less favorable tumor characteristics; high histological grade (OR=1.86, 95% CI 1.00-3.44), high Ki67 proliferative index (OR=2.18, 95% CI 1.18-4.02) as well as tumors of Luminal B-like subtype (OR=2.56, 95%CI 1.29-5.06). While no clear association between FGFR1 expression and MBD was found, FGF ligand (FGF1, FGF11, FGF18) expression was positively correlated with MBD.

Discussion

Taken together, these findings support a role of the FGF/FGFR1 system in early breast cancer which warrants further investigation in the MBD-breast cancer context.

Lifestyle Quality Indices and Female Breast Cancer Risk: A Systematic Review and Meta-Analysis

Breast cancer (BC) poses an important burden of disease, which probably could be reduced by adopting healthy lifestyles like healthy body weight, healthy diet, and physical activity, among others. Many studies have reported that adherence to healthy lifestyles may decrease BC risk. The main objective of this study was to estimate a summary association of studies evaluating a healthy lifestyle index and BC risk. A systematic review and meta-analysis following the Cochrane methodology were carried out. Observational studies, including healthy lifestyle indices and their association with BC, were searched from 4 databases. For the meta-analysis, random-effects model was used to evaluate overall BC risk, BC by molecular subtype and menopausal status. Thirty-one studies were included in the systematic review, and 29 studies in the meta-analysis. When the highest vs. the lowest category to a healthy lifestyle index were compared, the study identified a 20% risk reduction for BC in prospective studies (hazard ratio [HR] 0.80 95% CI: 0.78, 0.83) and an odds ratio (OR) of 0.74 (95% CI: 0.63, 0.86) for retrospective studies. The inverse association remained statistically significant when stratified by menopausal status, except for premenopausal BC in prospective studies. Furthermore, an inverse association was found for molecular subtypes estrogen receptor (ER+)/progesterone receptor (PR+): HR = 0.68 (95%CI: 0.63, 0.73), ER+/PR-: HR = 0.78 (95% CI: 0.67, 0.90) and ER-/PR-: HR = 0.77 (95% CI: 0.64, 0.92). Most studies scored at a low risk of bias and a moderate score for the certainty of the evidence. Adherence to a healthy lifestyle reduces the risk of BC, regardless of its molecular subtypes, which should be considered a priority to generate recommendations for BC prevention at a population level. International prospective register of systematic reviews (PROSPERO) ID: CRD42021267759.

The association of a combined healthy lifestyle with the risk of postmenopausal breast cancer subtypes in the Netherlands Cohort Study

The association between combined healthy lifestyle and postmenopausal breast cancer risk has been studied in various cohort studies, but only few evaluated the association with estrogen/progesterone (ER/PR) receptor subtypes of breast cancer, with inconsistent results. The relationship of a healthy lifestyle score (HLS) with risk of postmenopausal breast cancer (subtypes) was investigated in the Netherlands Cohort Study. In 1986, 62,573 women aged 55-69 years provided information on dietary and lifestyle habits. The HLS was derived from information on smoking, body mass index, physical activity, Mediterranean diet adherence, and alcohol intake. After 20.3 years of follow-up, multivariable case-cohort analyses were based on 2321 incident breast cancer cases, and 1665 subcohort members with complete data on lifestyles and confounders. The HLS showed a statistically significant inverse relationship with postmenopausal breast cancer risk, in a linear fashion. A one-point increment of the HLS was accompanied by a Hazard Ratio (HR) reduction of 20% for overall breast cancer. The associations between HLS and risk of ER/PR breast cancer subtypes were also significantly inverse, except for ER- breast cancer where the inverse association did not reach statistical significance. Per HLS-increment of one point, the HR reduction ranged from 14% for ER-breast cancer to 29% for ER + PR- breast cancer. These findings suggest that adhering to a combination of healthy modifiable lifestyle factors may substantially reduce the risk of overall postmenopausal breast cancer and its hormone receptor subtypes.

Healthy Lifestyle and Breast Cancer Risk in Palestinian Women: A Case-Control Study

The aim of this study was to investigate the association between a combined healthy lifestyle score and the risk of breast cancer (BC) in Palestinian women. A hospital-based case-control study compared 237 BC cases with confirmed diagnoses to 237 healthy controls. Women's lifestyle components were assessed using a validated questionnaire. A healthy lifestyle index (HLI) has been developed. We used logistic regression models to investigate the relationship between combined lifestyle scores and BC odds. The results revealed that HLI was significantly higher in the control group than in the study group. A higher HLI score was associated with a lower risk of BC in the multivariate analysis. The adjusted odds ratios (AOR) were 0.19 for all women, 0.15 for postmenopausal women, and 0.23 for premenopausal women when the HLI highest and lowest tertiles were compared. HLI score increases of one point resulted in a 41% reduction in the risk of BC for all women, a 42% reduction for postmenopausal and premenopausal women, and a 39% reduction for postmenopausal women. Women who live a healthy lifestyle, according to our findings, have a lower risk of breast cancer. BC prevention programs must promote long-term healthy food and lifestyle choices.

Interactions dietary components with expression level of breast cancer-related genes

Background

Dietary components can influence the effects of genetic background in breast cancer (BC). This review study aimed to investigate the effect of dietary components on the expression level of BC-related genes.

Methods

In this narrative review, Embase, PubMed, PsycInfo, and the Cochrane databases were used to collect the related papers with interactions of BC, genetics, and dietary intake. Appropriate keywords such as BC, gene expression, mutation, nutrient, and diet (alone and together) were applied for data collection.

Results

The association of BC with some genes including the BC1 gene (BRCA1), the human epidermal growth factor receptor 2 (HER2), and the fat mass and obesity-associated (FTO) gene can be affected by dietary components. Moderate B12 supplementation may be protective against BC in people with the inherited mutation of BRCA. The olive oil may have a protective effect against BC through several mechanisms such as suppressing HER-2 expression. Furthermore, high glycemic index foods may increase the risk of BC by the activation of the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway and the up-regulation of FTO gene expression.

Conclusion

There are interactions between BC, BC-related genes, and dietary intake. Dietary components such as macronutrients, micronutrients, and phytochemicals may regulate the expression level of BC-related genes. Further longitudinal studies are needed to confirm the associations between BC-related genes and diet and to discover the underlying mechanisms.

The effect of obesity on adipose-derived stromal cells and adipose tissue and their impact on cancer

The significant increase in the incidence of obesity represents the next global health crisis. As a result, scientific research has focused on gaining deeper insights into obesity and adipose tissue biology. As a result of the excessive accumulation of adipose tissue, obesity results from hyperplasia and hypertrophy within the adipose tissue. The functional alterations in the adipose tissue are a confounding contributing factor to many diseases, including cancer. The increased incidence and aggressiveness of several cancers, including colorectal, postmenopausal breast, endometrial, prostate, esophageal, hematological, malignant melanoma, and renal carcinomas, result from obesity as a contributing factor. The increased morbidity and mortality of obesity-associated cancers are attributable to increased hormones, adipokines, and cytokines produced by the adipose tissue. The increased adipose tissue levels observed in obese patients result in more adipose stromal/stem cells (ASCs) distributed throughout the body. ASCs have been shown to impact cancer progression in vitro and in preclinical animal models. ASCs influence tumor biology via multiple mechanisms, including the increased recruitment of ASCs to the tumor site and increased production of cytokines and growth factors by ASCs and other cells within the tumor stroma. Emerging evidence indicates that obesity induces alterations in the biological properties of ASCs, subsequently leading to enhanced tumorigenesis and metastasis of cancer cells. As the focus of this review is the interaction and impact of ASCs on cancer, the presentation is limited to preclinical data generated on cancers in which there is a demonstrated role for ASCs, such as postmenopausal breast, colorectal, prostate, ovarian, multiple myeloma, osteosarcoma, cervical, bladder, and gastrointestinal cancers. Our group has investigated the interactions between obesity and breast cancer and the mechanisms that regulate ASCs and adipocytes in these different contexts through interactions between cancer cells, immune cells, and other cell types present in the tumor microenvironment (TME) are discussed. The reciprocal and circular feedback loop between obesity and ASCs and the mechanisms by which ASCs from obese patients alter the biology of cancer cells and enhance tumorigenesis will be discussed. At present, the evidence for ASCs directly influencing human tumor growth is somewhat limited, though recent clinical studies suggest there may be some link.

Healthy lifestyle index and risk of pancreatic cancer in the Women's Health Initiative

PURPOSE

Lifestyle factors such as smoking, alcohol, body weight, physical activity, and diet quality have been associated with the risk of pancreatic cancer. However, studies of their combined association in women are limited.

METHODS

Data on smoking habits, alcohol intake, diet composition, recreational physical activity, body weight, and waist circumference, obtained at recruitment for 136,945 postmenopausal women (aged 50-79 years) participating in the Women's Health Initiative study, were categorized separately, with higher scores for each variable assigned to the categories representing healthier behaviors. The combined healthy lifestyle index (HLI) score, created by summing the scores for each risk factor, was grouped into quartiles. We used multivariable-adjusted Cox regression to estimate hazard ratios (HR) and 95% confidence intervals (CI) for pancreatic cancer risk in association with the HLI.

RESULTS

Over an average follow-up period of approximately 16.0 years, 1,119 incident cases of pancreatic cancer were ascertained. Compared to women in the lowest HLI quartile, those in the upper quartiles (qt) had a reduced risk of pancreatic cancer (multivariable-adjusted HRqt3rd 0.83, 95% CI 0.74-0.99; and HRqt4th 0.74, 95% CI 0.62-0.88, respectively, p trend = 0.001). Use of waist circumference instead of BMI in the HLI score yielded similar results. Among women who were either non-diabetic or non-smokers, high HLI was also associated with reduced risk (HRqt4th 0.78, 95% CI 0.65-0.85 and HRqt4th 0.80, 95% CI 0.66-0.97, respectively). Stratification by BMI categories (18.5- < 25.0, 25.0- < 30.0 and > 30.0 kg/m2) showed similar results in all groups.

CONCLUSIONS

Our findings suggest that in postmenopausal women, a healthy lifestyle is associated with reduced risk of pancreatic cancer.

A review of research on the intersection between breast cancer and cardiovascular research in the Women's Health Initiative (WHI)

Both obesity and metabolic syndrome are linked to increased incidence of type 2 diabetes, cardiovascular disease (CVD), and cancers of the breast (post-menopausal), and other obesity-related cancers. Over the past 50 years, the worldwide prevalence of obesity and metabolic syndrome has increased, with a concomitant higher incidence of associated co-morbidities and mortality. The precise mechanism linking metabolic syndrome to increased cancer incidence is incompletely understood, however, individual components of metabolic syndrome have been linked to increased breast cancer incidence and worse survival. There is a bidirectional relationship between the risk of CVD and cancer due to a high burden of shared risk factors and higher rates of CVD among cancer survivors, which may be impacted by the pro-inflammatory microenvironment associated with metabolic syndrome and cancer-directed therapies. The Women's Health Initiative (WHI) is an excellent resource to study a dual relationship between cancer and CVD (cardio-oncology) with extensive information on risk factors and long-term outcomes. The purpose of this review is to provide an overview of research on cardio-oncology conducted utilizing WHI data with focus on studies evaluating both breast cancer and CVD including shared risk factors and outcomes after cancer. The review also includes results on other obesity related cancers which were included in the analyses of breast cancer, articles looking at cancer after heart disease (reverse cardio-oncology) and the role of Clonal Hematopoiesis of Indeterminate Potential (CHIP) as a shared risk factor between CVD and cancer. A summary of pertinent WHI literature helps to delineate the direction of future research evaluating the relationship between CVD and other cancer sites, and provides information on the opportunity for other novel analyses within the WHI.

Testing a breast cancer prevention and a multiple disease prevention weight loss programme amongst women within the UK NHS breast screening programme-a randomised feasibility study

Background

Excess weight and unhealthy behaviours (e.g. sedentariness, high alcohol) are common amongst women including those attending breast screening. These factors increase the risk of breast cancer and other diseases. We tested the feasibility and acceptability of a weight loss/behaviour change programme framed to reduce breast cancer risk (breast cancer prevention programme, BCPP) compared to one framed to reduce risk of breast cancer, cardiovascular disease (CVD) and diabetes (T2D) (multiple disease prevention programme, MDPP).

Methods

Women aged 47-73 years with overweight or obesity (n = 1356) in the NHS Breast Screening Programme (NHSBSP) were randomised (1:2) to be invited to join a BCPP or a MDPP. The BCPP included personalised information on breast cancer risk and a web and phone weight loss/behaviour change intervention. The MDPP also included an NHS Health Check (lipids, blood pressure, HbA1c and personalised feedback for risk of CVD [QRISK2] and T2D [QDiabetes and HbA1c]). Primary outcomes were uptake and retention and other feasibility outcomes which include intervention fidelity and prevalence of high CVD and T2D risk. Secondary outcomes included change in weight.

Results

The BCPP and MDPP had comparable rates of uptake: 45/508 (9%) vs. 81/848 (10%) and 12-month retention; 33/45 (73%) vs. 53/81 (65%). Both programmes had a high fidelity of delivery with receipt of mean (95% CI) 90 (88-98% of scheduled calls, 91 (86-95%) of scheduled e-mails and 89 (76-102) website entries per woman over the 12-month period. The MDPP identified 15% of women with a previously unknown 10-year CVD QRISK2 of ≥ 10% and 56% with 10-year Qdiabetes risk of ≥ 10%. Both groups experienced good comparable weight loss: BCPP 26/45 (58%) and MDPP 46/81 (57%) with greater than 5% weight loss at 12 months using baseline observation carried forward imputation.

Conclusions

Both programmes appeared feasible. The MDPP identified previously unknown CVD and T2D risk factors but does not appear to increase engagement with behaviour change beyond a standard BCPP amongst women attending breast screening. A future definitive effectiveness trial of BCPP is supported by acceptable uptake and retention, and good weight loss.

Trial registration

ISRCTN91372184, registered 28 September 2014.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-021-00947-4.

Combined Lifestyle Behaviors and the Incidence of Common Cancer Types in the Norwegian Women and Cancer Study (NOWAC)

INTRODUCTION

Only a small number of studies have examined the impact of combined lifestyle behaviors on cancer incidence, and never in a Norwegian population.

PURPOSE

To examine linear and nonlinear associations of combined lifestyle factors, assessed through a healthy lifestyle index (HLI), with the incidence of postmenopausal breast, colorectal, lung, postmenopausal endometrial, postmenopausal ovarian, pancreatic, and kidney cancer among women in Norway.

METHODS

This prospective study included 96,869 women enrolled in the Norwegian Women and Cancer (NOWAC) cohort. Baseline information on lifestyle factors was collected between 1996 and 2004. The HLI was constructed from five lifestyle factors: physical activity level, body mass index, smoking, alcohol consumption, and diet. Each factor contributed 0 to 4 points to the HLI score, which ranged from 0 to 20, with higher scores representing a healthier lifestyle. Multiple imputation was used to handle missing data. Cox proportional hazard regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). Restricted cubic splines were used to examine nonlinearity in the associations.

RESULTS

The HRs for a one-point increment on the HLI score were 0.97 (95% CI: 0.96-0.98) for postmenopausal breast cancer, 0.98 (0.96-1.00) for colorectal cancer, 0.86 (0.84-0.87) for lung cancer, 0.93 (0.91-0.95) for postmenopausal endometrial cancer, 0.99 (0.96-1.02) for postmenopausal ovarian cancer, 0.92 (0.89-0.95) for pancreatic cancer, and 0.94 (0.91-0.97) for kidney cancer. Nonlinearity was observed for the inverse associations between HLI score and the incidence of lung cancer and postmenopausal breast cancer.

CONCLUSION

Based on our results, healthier lifestyle, as assessed by the HLI score, was associated with lower incidence of postmenopausal breast, colorectal, lung, postmenopausal endometrial, pancreatic, and kidney cancer among women, although the magnitude and linearity varied. Adoption of healthier lifestyle behaviors should be a public health priority to reduce the cancer burden among Norwegian women.

Road and railway noise and risk for breast cancer: A nationwide study covering Denmark

OBJECTIVE

Previous studies have suggested that transportation noise may increase risk for breast cancer, but existing literature is scarce and inconclusive. We aimed to investigate associations between road traffic and railway noise and risk for breast cancer across the entire Danish female population.

METHODS

For all 2.8 million residential addresses across Denmark, we modelled road and railway noise at the most and least exposed façades for the period 1990-2017. We calculated 10-year time-weighted mean noise exposure for 1.8 million women aged >35 years, of whom 66,006 developed breast cancer during follow-up from 2000 to 2017. We analysed data using Cox proportional hazards models with noise exposure included as 10-year running means and adjusted for a number of individual and area-level socioeconomic co-variates and air pollution with fine particles estimated for all addresses.

RESULTS

For exposures at the least exposed façade, we found that a 10 dB increase in 10-year time-weighted noise was associated with incidence rate ratios (IRRs) and 95% confidence intervals (CI) for breast cancer of 1.032 (1.019-1.046) for road noise and 1.023 (0.993-1.053) for railway noise. For exposures at the most exposed façade, the IRRs (95% CIs) were 1.012 (1.002-1.022) for road noise and 1.020 (1.001-1.039) for railway noise. Associations were strongest among women with human epidermal growth factor receptor 2 negative breast cancer.

CONCLUSIONS

Road traffic and railway noise were associated with higher risk for breast cancer, especially noise at the least exposed façade, which is a proxy for noise exposure during sleep.

Effects of major lifestyle factors on breast cancer risk: impact of weight, nutrition, physical activity, alcohol and tobacco

Breast cancer (BC) is the most commonly diagnosed cancer and second most common cause of cancer death in US women. Family history and genetics are well-known BC risk factors, but they only account for 15–20% of BC cases. Therefore, in addition to family history, healthcare providers must consider a woman’s modifiable and nonmodifiable personal risk factors that are associated with an increase in BC risk. The World Cancer Research Fund/American Institute for Cancer Research estimate that 30% of BC cases in the US are preventable. Lifestyle education is imperative given the magnitude of BC occurrence. Evidence supports prevention as an effective, long-term strategy for reducing risk. Healthcare providers are key stakeholders in empowering patients to adopt a healthy lifestyle for primary BC prevention. In this paper, we review the available evidence on modifiable BC risk including weight management, nutrition, physical activity, alcohol and tobacco use and provide strategies to counsel patients on lifestyle modifications.

Cancer Prevention and Screening for Older Adults: Part 2. Interventions to Prevent and Screen for Breast, Prostate, Cervical, Ovarian, and Endometrial Cancer

The incidence of most cancers increase with age. Cancer is the second most common cause of death in older adults after cardiovascular disease. Many common cancers in older adults can be prevented from occurring or can be identified at an early stage and treated effectively. Although cancer is feared primarily because of premature mortality, for many older adults, preventing and identifying cancer in its early stages, in an attempt to reduce discomfort and disability associated with advanced cancer and cancer treatment, is also a priority. Overscreening for cancer in older adults can lead to unnecessary diagnostic testing and unnecessary treatment. Both older adults and their healthcare providers need guidance on the appropriate use of cancer prevention and screening interventions. This is the second part of a two-part clinical review on cancer prevention and screening for adults aged 65 and older. Guidance is provided regarding the prevention and early identification of breast, prostate, cervical, ovarian, and endometrial cancer. The prevention of lung, colorectal, bladder, and kidney cancer is addressed in Part 1.

Genetic Factors, Adherence to Healthy Lifestyle Behavior, and Risk of Invasive Breast Cancer Among Women in the UK Biobank

BACKGROUND

Breast cancer is considered to result from a combination of genetic and lifestyle-related factors, but the degree to which an overall healthy lifestyle may attenuate the impact of multiple genetic variants on invasive breast cancer risk remains equivocal.

METHODS

Using Cox proportional hazards regression models, we examined the association of a modified healthy lifestyle index (HLI) with risk of invasive breast cancer by genetic risk group among 146 326 women from the UK Biobank. We generated an HLI score based on a combination of diet, physical activity, smoking, alcohol consumption and anthropometry, and a polygenic risk score (PRS) using 304 breast cancer-associated genetic loci.

RESULTS

Among premenopausal and postmenopausal women, a favorable lifestyle (highest tertile) was associated with 22% and 31% reductions in invasive breast cancer risk, respectively (hazard ratio [HR]high vs low = 0.78, 95% confidence interval [CI] = 0.64 to 0.94; HRhigh vs low = 0.69, 95% CI = 0.63 to 0.77, respectively), whereas a high PRS (highest tertile) was associated with more than a doubling in the risk in both groups. For premenopausal women, the greatest risk reduction in association with the HLI was seen among those with a high PRS (HRhigh vs low = 0.73, 95% CI = 0.75 to 0.95). In postmenopausal women, those with a favorable lifestyle had 30%, 29%, and 32% reductions in risk of invasive breast cancer in the low, intermediate, and high PRS groups, respectively (HRhigh vs low = 0.70, 95% CI = 0.56 to 0.88; HRhigh vs low = 0.71, 95% CI = 0.59 to 0.84; and HRhigh vs low = 0.68, 95% CI = 0.59 to 0.78, respectively). There was an additive but not multiplicative interaction between the HLI score and PRS for postmenopausal and, to a lesser extent, premenopausal women.

CONCLUSION

Our findings support the view that an overall healthy lifestyle may attenuate the impact of genetic factors on invasive breast cancer risk among women of European ancestry.

Diet and Transgenerational Epigenetic Inheritance of Breast Cancer: The Role of the Paternal Germline

The past decade has made evident that in addition to passing their genetic material at conception, parents also transmit a molecular memory of past environmental experiences, including nutritional status, to their progeny through epigenetic mechanisms. In the 1990s, it was proposed that breast cancer originates in utero. Since then, an overwhelming number of studies in human cohorts and animal models have provided support for that hypothesis. It is becoming clear, however, that exposure in the parent generation can lead to multigenerational and transgenerational inheritance of breast cancer. Importantly, recent data from our lab and others show that pre-conception paternal diets reprogram the male germline and modulate breast cancer development in offspring. This review explores the emerging evidence for transgenerational epigenetic inheritance of breast cancer focusing on studies associated with ancestral nutritional factors or related markers such as birth weight. We also explore paternal factors and the epigenetic mechanisms of inheritance through the male germline while also reviewing the existing literature on maternal exposures in pregnancy and its effects on subsequent generations. Finally, we discuss the importance of this mode of inheritance in the context of breast cancer prevention, the challenges, and outstanding research questions in the field.

Adherence to the 2018 World Cancer Research Fund/American Institute for Cancer Research Recommendations and Breast Cancer in the SUN Project

A proportion of breast cancer cases are attributable to combined modifiable risk factors. The World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) has recently updated the recommendations for cancer prevention and a standard scoring system has been published. The aim of this study was to evaluate the association between compliance with the 2018 WCRF/AICR cancer prevention recommendations (Third Expert Report) and the risk of breast cancer in the SUN (“Seguimiento Universidad de Navarra”) prospective cohort. Spanish female university graduates, initially free of breast cancer, were included (n = 10,930). An 8-item score to measure compliance to the recommendations was built: body fat, physical activity, consumption of wholegrains/vegetables/fruit/beans, “fast foods”, red/processed meat consumption, sugar-sweetened drinks consumption, alcohol intake, and breastfeeding. A stratified analysis was conducted according to menopausal status. A non-significant inverse association was observed for overall breast cancer. The inverse association became statistically significant for post-menopausal breast cancer after multivariable adjustment (hazard ratio for > 5 vs. ≤ 3 points = 0.27; 95% CI: 0.08-0.93). The results suggested that the possible inverse association with breast cancer was attributable to the combined effects of the different nutritional and lifestyle components.

DNA Methylation in RARβ Gene as a Mediator of the Association Between Healthy Lifestyle and Breast Cancer: A Case-Control Study

Purpose

Lifestyle factors and methylation in the retinoic acid receptor β (RARβ) gene are associated with breast cancer (BC). This study aims to examine the mediation effect of RARβ methylation on the association between healthy lifestyle and BC in Chinese women.

Patients and Methods

This case–control study consisted of 408 BC patients and 573 controls. A healthy lifestyle score (HLS) was constructed based on diet, alcohol use, physical activity, body mass index and smoking. The mediation effect of RARβ methylation in peripheral blood leukocytes was assessed in a causal mediation model using R package Lavaan.

Results

A higher HLS was significantly associated with lower risk of BC (P-value<0.001). In mediation analyses, the total effect of HLS on BC measured as a regression coefficient was significant (−0.237). The indirect effects of HLS on RARβ methylation (−0.153) and RARβ methylation on BC (0.220) were both significant. The significant mediation effect of RARβ methylation on the HLS-BC association was estimated at 14.3%.

Conclusion

The relationship between healthy lifestyle and BC is partly mediated by RARβ methylation, suggesting that epigenetic modifications play a role in the underlying mechanisms in response to lifestyles and contribute to the development of BC.

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.

Association between healthy lifestyle score and breast cancer

BACKGROUND

Majority of earlier studies have assessed the association between individual lifestyle factors and the risk of breast cancer (BC); however, limited information is available linking the whole lifestyle factors to BC. We aimed to examine the association between combined lifestyle score (diet, physical activity (PA) and smoking) and risk of BC in Iranian population.

METHODS

This population-based case-control study included 350 newly diagnosed cases of BC and 700 healthy controls randomly selected from adult women. Dietary intakes, PA and smoking status of study participants were examined using validated questionnaires. The lifestyle risk factors examined in this study included cigarette smoking, physical inactivity, and Healthy Eating Index-2010 (HEI-2010). The lifestyle score ranged from zero (non-healthy) to 3 (most healthy) points. Logistic regression models were fitted to investigate the association between combined lifestyle scores and odds of BC.

RESULTS

Mean age and body mass index (BMI) of study participants were 62.4 years and 24.3 kg/m², respectively. In the whole study population, individuals with the highest healthy lifestyle score (HLS) were 0.38 times less likely to have BC than those with the lowest score (OR: 0.62; 95% CI: 0.40, 0.93, P_trend = 0.01). The analysis by menopausal status showed that postmenopausal women with the highest HLS had 44% lower odds of BC compared with those with the lowest score (OR: 0.56; 95% CI: 0.36, 0.88, P _trend = 0.004). Such association was not seen in premenopausal women. After analyzing each component of HLS, we found that individuals with the highest HEI score were 46% less likely to have BC than those with the lowest score (OR: 0.54; 95% CI: 0.35, 0.82, P_trend <  0.001). No other significant associations were found between PA and smoking and risk of BC.

CONCLUSIONS

Significant inverse associations were found between HLS and HEI with BC especially among postmenopausal women. Prospective studies are required to confirm these findings.

Joint tobacco smoking and alcohol intake exacerbates cancer risk in women- the Danish nurse cohort

PURPOSE

To explore separate and combined tobacco and alcohol use and risk of overall, smoking-related, alcohol-related, breast and gynecological cancers in women.

METHOD

Questionnaires from 19,898 women in The Danish Nurse Cohort in 1993 were linked to registries on hospitalizations, death causes and migration until Dec 2016. Cancer risk by tobacco and alcohol was estimated using Cox proportional hazards models.

RESULTS

16,106 nurses, aged >44 years (mean = 56), were eligible for analysis. Throughout 23 years (mean follow-up = 18.8 years) overall cancers counted 4,968. Of these, 1,897, 2,231, 1,407 and 579 events were smoking-related, alcohol-related, breast cancers and gynecological cancers. Increased risks of overall, smoking-related, and breast cancer were observed for current smoking and excess alcohol intake (>14 units/week), separately, compared to never smoking and light drinking (1-7 units/week) respectively. Moderate drinking (8-14 units/week) increased the risk of alcohol-related and breast cancer. Additional risk increases were observed among smokers drinking alcohol above light levels for overall, smoking-related, alcohol-related and breast cancer (HR = 1.40, 95% CI:1.30-1.51, HR = 1.72, 95% CI:1.52-1.94, HR = 1.33, 95% CI:1.26-1.40, HR = 1.32, 95% CI:1.15-1.53, respectively), compared to non-smokers drinking lightly. These risks increased further for smokers drinking above moderate levels (HR = 1.49, 95% CI:1.36-1.63, HR = 1.97, 95% CI:171.-2.26, HR = 1.40, 95% CI:1.22-1.60, HR = 1.33, 95% CI:1.12-1.57, respectively). No significant associations were found for gynecological cancer.

CONCLUSIONS

Smoking and alcohol, both separately and combined, increased risks of overall, smoking-related, alcohol-related and breast cancer; combined use resulted in incremental risk increases. Co-use of smoking and alcohol represent an extensive threat to public health; thus, prevention could benefit from combined targeting.

Sedentary Behavior and Alcohol Consumption Increase Breast Cancer Risk Regardless of Menopausal Status: A Case-Control Study

Identification of modifiable risk factors for breast cancer is critical for primary prevention of the disease. The aim of this study was to evaluate how certain lifestyle variables modify the chances of developing breast cancer based on menopausal status. A case-control study was performed in a group of 542 women, 197 who were diagnosed with breast cancer and 344 control individuals. The groups were matched by age, body mass index, and menopausal status. Participants were evaluated for level of physical activity, alcohol consumption, smoking habit, weight, height, and waist circumference (WC). A multivariate logistic regression model was used to estimate odds ratios and 95% confidence intervals (95% CI). Regular consumption of alcoholic beverages (2.91, 95% CI 1.58-5.38 and 1.86, 95% CI 1.15-3.03) and sedentary behavior (2.08; 95% CI 1.12-3.85 and 1.81; 95% CI 1.12-2.94) were associated with breast cancer risk in pre- and postmenopausal women, respectively. High WC (3.31, 95% CI 1.45-7.55) was associated with an increased risk of developing breast cancer in premenopausal women. While in postmenopausal women, current smoking (2.43, 95% CI 1.01-5.83) or previous history of smoking (1.90; 95% CI 1.14-3.14) increased the chances of developing breast cancer. Sedentary behavior and current consumption of alcoholic beverages were more likely to increase the risk of developing breast cancer regardless of menopausal status.

Multiple exposure to environmental factors and variations in CYP27B1 and the microRNA-binding site of IL-13 are associated with breast cancer risk

Purpose

Several molecular epidemiology studies have evidenced an association of environmental factors and genetic polymorphisms with breast cancer (BC) risk. However, most have considered the functions of a single element rather than combined effects.

Methods

This case‐control study of 693 newly‐diagnosed BC cases and 714 cancer‐free controls evaluated the effect of multiple exposures to environmental factors and polymorphisms in CYP27B1 and IL‐13 on BC risk. Genotypes were detected using TaqMan genotyping. Combinations and interactions were analyzed using cross‐over analysis and multivariate logistic regression. Combining exposure models were assessed using classification and regression tree and multivariate logistic regression analyses.

Results

No significant independent association was observed for any polymorphism in CYP27B1 or IL‐13 with the risk of BC. However, significant combined effects were noted for ≥1 time/wk physical activity with rs10877012 (adjusted odds ratio [OR_adj] = 0.21, 95% confidence interval [CI] = 0.11‐0.39) and rs4646536 (OR_adj = 0.21, 95% CI = 0.11‐0.39) in CYP27B1. Furthermore, taking garlic ≥4 times/wk, ≥1 time/wk physical activity, and a psychological index score ≥33 all displayed significant combined effects with three IL‐13 polymorphisms. These relationships remained significant after Bonferroni correction for multiple comparisons. Combining exposure models indicated that compared with consuming garlic ≥4 times/wk, five models (model 5, OR_adj = 2.94, 95% CI = 1.07‐8.06; model 6, OR_adj = 10.26, 95% CI = 5.81‐18.10; model 7, OR_adj = 5.05, 95% CI = 2.78‐9.17; model 8, OR_adj = 3.95, 95% CI = 2.79‐5.58; and model 9, OR_adj = 7.97, 95% CI = 5.26‐12.07) showed a significant increased risk.

Conclusions

Our findings suggest that personalized adjustments to diet and behavioral patterns may aid BC prevention in variant carriers of CYP27B1 and IL‐13.

Healthy lifestyle and breast cancer risk: A case-control study in Morocco

BACKGROUND

Some modifiable risk factors have been independently associated with breast cancer (BC) risk in Moroccan women, but no studies have investigated their joint association. This study aimed to investigate the association between a Healthy Lifestyle Index (HLI) score and BC risk among Moroccan women.

METHODS

In this case-control study, 300 incident BC cases and 300 controls, matched by age and area of residence were recruited. Cases were women newly-diagnosed with histopathologically-confirmed BC at the University Hospital in Fez, Morocco. Controls were randomly selected healthy women recruited from 6 primary health centers in Fez. HLI scores developed within this study were assigned to participants based on 11 factors (red and processed meat, white meat, cream, cheese, fish, fruit and vegetables, physical activity, BMI, smoking, alcohol consumption, and breastfeeding), where 0 was given to unhealthy and 0.5 or 1 to healthy levels of each factor. Conditional and unconditional logistic regression models were used to assess the association between HLI scores and BC risk.

RESULTS

Mean of HLI scores were 8.1 (±1.1) and 9.0 (±0.9) in cases and controls, respectively, p < 0.01. After adjusting for potential confounders, one-point increment in the HLI score was associated with 56% (95% CI, CI: 39-68%), 49% (95% CI: 30-63%), and 59% (95% CI: 40-72%) lower risks of BC in all, premenopausal, and postmenopausal women, respectively.

CONCLUSION

High HLI scores were associated with decreased risk of BC in Moroccan women. These findings suggest that BC prevention policies should include strategies for engaging Moroccan women in healthy lifestyles.

Combining Variables for Cancer Risk Estimation: Is the Sum Better than the Parts?

Examining joint exposures of modifiable breast cancer risk factors may provide advantages over individual exposure-disease association analyses. Using the Healthy Lifestyle Index, Arthur and colleagues analyzed the joint impacts of diet, alcohol, smoking, physical activity, and obesity on breast cancer risk, and subtypes, in postmenopausal women enrolled in the Women's Health Initiative. The analysis provides data for population-attributable risk estimations and future prevention trials to target multiple risk factors. The public health messages for the individual risk factors remain unchanged, however, and it is still not clear whether improving one risk factor can counteract the adverse effects of another. Cancer Prev Res; 11(6); 313-6. ©2018 AACRSee related article by Arthur et al., p. 317.