Obesity, body size, and risk of postmenopausal breast cancer: the Women's Health Initiative (United States)

Consequences of daily self-weighing: a pilot study in higher-weight women with a history of breast cancer

Self-monitoring weight is commonly recommended for higher-weight women with a history of breast cancer, despite evidence demonstrating potentially negative psychological consequences of frequent self-weighing. The extent to which higher-weight women with breast cancer experience emotional and behavioral consequences in response to daily self-weighing is unknown. In this pilot study, women (n = 51) with a history of breast cancer in a behavioral weight management program completed a weeklong daily diary protocol. Participants were asked to self-weigh every morning and report on subsequent weight-related shame and guilt, and end-of-day engagement in compensatory exercise, diet, and purging behaviors. Women reported higher levels of guilt on days when their body weight was higher than usual, and when there was more discrepancy between their current vs. goal weight. Additionally, women engaged in higher levels of compensatory diet behavior on days when they experienced more weight-related guilt than usual. Based on these preliminary findings, daily self-weighing may be associated with harmful emotional and behavioral consequences among higher-weight women with a history of breast cancer.

Anthropometric Measures and Fuchs' Endothelial Corneal Dystrophy: The Women's Health Initiative Observational Study

Purpose

Both genetic and environmental factors contribute to the development of Fuchs' endothelial corneal dystrophy (FECD), the most common indication for corneal transplantation in the United States. Prior studies have suggested an association of height, weight, or body mass index (BMI) with FECD. We examined the association between anthropometric measures and incident FECD in the Women's Health Initiative Observational Study (WHI-OS) of postmenopausal women (n = 22,983).

Methods

Medicare Part B claims data from the WHI-OS baseline visit (1993-1998) to 2019 were used to identify incident cases of FECD. At baseline and follow-up year 3, weight, height, waist circumference (WC), and hip circumference were measured. At baseline, women were asked to recall their historic weight at ages 18, 35, and 50 years. At follow-up years 1 and 4 to 8, the women were asked to self-report their weight. Height and weight were used to calculate BMI at each time point. Adjusted hazard ratios (HRs), 95% confidence intervals (CI), and p for trend for incident FECD were estimated by measures of historic BMI, baseline anthropometrics measures, and anthropometric measures that incorporated more than one baseline visit (time-varying). Anthropometric measures were parameterized as continuous and categorical in analyses.

Results

There were 1399 incident FECD cases with an annualized incidence rate of 5.06 per 1000 person-years (95% CI = 4.80-5.33) over 276,443 person-years of follow-up. No statistically significant associations were observed between baseline height and risk of FECD. Women with baseline BMIs ≥35 (obesity II) compared to <25 kg/m2 (normal weight or underweight) had lower risk of incident FECD (HR = 0.68, 95% CI = 0.53-0.88) with a P value = 0.0373 for an ordinal trend analysis across BMI categories. Significant inverse associations were observed for continuous measures of WC (HR = 0.97, 95% CI = 0.95-0.99 per 5 cm increase) and waist-to-hip ratio (WHR; HR = 0.92, 95% CI = 0.86-0.99 per 0.1 unit increase). No statistically significant associations were observed for time-varying BMI, but time-varying WC and WHR has statistically significant inverse associations with risk for FECD (data not shown).

Conclusions

In this cohort of postmenopausal women, BMI, WC, and WHR were inversely associated with incident FECD. These findings generally support the potential role of anthropometric measures, particularly those indicative of abdominal obesity in FECD susceptibility in women.

Implications of obesity and insulin resistance for the treatment of oestrogen receptor-positive breast cancer

Breast cancer is the most common cancer in women, and incidence rates are rising, it is thought in part, due to increasing levels of obesity. Endocrine therapy (ET) remains the cornerstone of systemic therapy for early and advanced oestrogen receptor-positive (ER + ) breast cancer, but despite treatment advances, it is becoming more evident that obesity and insulin resistance are associated with worse outcomes. Here, we describe the current understanding of the relationship between both obesity and diabetes and the prevalence and outcomes for ER+ breast cancer. We also discuss the mechanisms associated with resistance to ET and the relationship to treatment toxicity.

Microsurgical Breast Reconstruction can be Performed Safely in Patients with Obesity

BACKGROUND

 Numerous studies have shown that obesity is a risk factor for postoperative complications following breast reconstruction. Hence, obesity has traditionally been considered a relative contraindication to microsurgical breast reconstruction. In this study, we investigated the impact of obesity on outcomes following microsurgical breast reconstruction.

METHODS

 A retrospective analysis of 200 consecutive patients who underwent microsurgical breast reconstruction with free abdominal flaps was performed. Subjects were divided into Nonobese (body mass index [BMI] < 30 kg/m2) and Obese (BMI ≥ 30 kg/m2) cohorts. Univariate and multivariate analyses were performed to evaluate differences in patient characteristics, complication rates, and efficiency metrics between the two groups.

RESULTS

 Of the 200 subjects included in the study, 128 were Nonobese, 72 were Obese. The prevalence of diabetes (3.9 vs. 16.9%, p = 0.002) and hypertension (14.7 vs. 39.4%, p < 0.001) were significantly greater in the Obese cohort. Among unilateral reconstructions, postoperative length of stay (LOS) was longer among Obese patients (3.1 vs. 3.6 days, p = 0.016). Seroma occurred more frequently in Obese patients following bilateral reconstruction (5.7 vs. 0.0%, p = 0.047). Otherwise, there were no significant differences in complication rates between the groups. On multivariate analysis, BMI was not independently associated with complications, LOS, or operative time.

CONCLUSION

 The improvements in clinical and patient-reported outcomes that have been associated with postmastectomy breast reconstruction do not exclude obese women. This study indicates that microsurgical breast reconstruction can be performed safely and efficiently in patients with obesity.

Mammary adipocytes promote breast tumor cell invasion and angiogenesis in the context of menopause and obesity

The mechanism(s) underlying obesity-related postmenopausal (PM) breast cancer (BC) are not clearly understood. We hypothesized that the increased local presence of 'obese' mammary adipocytes within the BC microenvironment promotes the acquisition of an invasive and angiogenic BC cell phenotype and accelerates tumor proliferation and progression. BC cells, treated with primary mammary adipocyte secretome from premenopausal (Pre-M) and PM obese women (ObAdCM; obese adipocyte conditioned-media) upregulated the expression of several pro-tumorigenic factors including VEGF, lipocalin-2 and IL-6. Both Pre-M and PM ObAdCM stimulated endothelial cell recruitment and proliferation and significantly stimulated BC cell proliferation, migration and invasion. IL-6 and LCN2 induced STAT3/Akt signaling in BC cells and STAT3 inhibition abrogated the ObAdCM-stimulated BC cell proliferation and migration. Expression of proangiogenic regulators including VEGF, NRP1, NRP2, IL8RB, TGFβ2, and TSP-1 were found to be differentially regulated in mammary adipocytes from obese PM women. Comparative RNAseq indicated an upregulation of PI3K/Akt signaling, ECM-receptor interactions and lipid/fatty acid metabolism in PM versus Pre-M mammary adipocytes. Our results demonstrate that irrespective of menopausal status, cross-talk between obese mammary adipocytes and BC cells promotes tumor aggressiveness and suggest that targeting the LCN2/IL-6/STAT3 signaling axis may be a useful strategy in obesity-driven breast tumorigenesis.

Frequency of Deleterious Germline Variants in HER2-Low Breast Cancer Patients Using a Hereditary Multipanel Gene Testing

HER2-Low is defined as low levels of HER2 expression, based on a score of 1+ on immunohistochemical (IHC) assay or as an IHC score of 2+ and negative results on in situ hybridization (ISH or FISH). They are a heterogeneous population of breast cancers that vary in prognosis and sensitivity to systemic treatments. The frequency and clinical characteristics of pathogenic germline variants (PGVs) in HER2-Low breast cancer (BC) patients is not defined. We analyzed results from patients with BC who underwent multi-gene panel testing (MGPT) (maximum 145 genes) between 2018-2019. We reclassified HER-2 status accordingly. Relationships between the variables of interest were assessed by adopting the proportional regression Cox models. Of a total of 167 BC patients who underwent MGPT, half were hormone-receptor-positive. The median age was 45 years. About two thirds of the patients were in the earlier stage of BC. A total of 57% of the cases were reclassified as HER-2-negative or -Low. PGVs were found in 19% of the patients overall, as follows: seven BRCA1, four BRCA2, two ATM, one ATR, two CFTR, three CHEK2, one FANCA, one MERTK, one MLH1, three MUTYH, one RAD50, three RAD51C, one RECQL4, and two TP53 mutations. In HER2-Low, 26.5% of the patients had PGVs, and in the overall cohort, this was 19.8%. In conclusion, differences in the prevalence of deleterious germline mutations in HER2-Low BC patients compared to non-HER2-Low BC patients were identified. Similar alterations in BRCA were observed in this group of patients compared to the overall cohort. Germline genetic tests should be evaluated in larger cohorts of patients with HER2-Low status to better address the findings.

Exosomes isolated from metabolically unhealthy normal weight and overweight phenotypes deteriorate the ER/PR positive breast cancer behavior

Purpose

Obesity has been linked to a higher risk of postmenopausal breast cancer Yet, research indicates an opposite correlation between obesity and premenopausal breast cancer risk. Various obesity phenotypes based on metabolic health could play a significant part. This study aims to assess how plasma exosomes taken from women with varying obesity phenotypes impact MCF-7 cell migration, matrix metalloproteinase-2 activity, and apoptosis.

Methods

The characterization of isolated exosomes and their internalization into MCF-7 cells was evaluated. The treatment of MCF-7 cells with exosomes isolated from different groups was done. Migration, the activity of MMP-2, mRNA expression of Bax and Bcl-2, protein expression of p-53 and Thr55 p-p53, and apoptosis were assessed.

Results

Isolated exosomes from unhealthy obese individuals increase MCF-7 cell migration. Regarding MMP activities, unhealthy normal weight and overweight and healthy obese groups isolated exosomes increase the MMP-2 activity than the treated group with exosomes isolated from counterpart groups. Furthermore, unhealthy normal weight and overweight and healthy obese obtained exosomes decrease apoptosis compared to counterpart groups.

Conclusion

Altogether, plasma exosomes derived from both unhealthy individuals with normal weight and overweight status, as well as those with unhealthy obesity, negatively impacted the behavior of estrogen/progesterone receptor-positive breast cancer cells.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01295-1.

Is There a Special Role for Ovarian Hormones in the Pathogenesis of Lobular Carcinoma?

Lobular carcinoma represent the most common special histological subtype of breast cancer, with the majority classed as hormone receptor positive. Rates of invasive lobular carcinoma in postmenopausal women have been seen to increase globally, while other hormone receptor-positive breast cancers proportionally have not followed the same trend. This has been linked to exposure to exogenous ovarian hormones such as hormone replacement therapy. Reproductive factors resulting in increased lifetime exposure to endogenous ovarian hormones have also been linked to an increased risk of lobular breast cancer, and taken together, these data make a case for the role of ovarian hormones in the genesis and progression of the disease. In this review, we summarize current understanding of the epidemiological associations between ovarian hormones and lobular breast cancer and highlight mechanistic links that may underpin the etiology and biology.

How does weight gain since the age of 18 years affect breast cancer risk in later life? A meta-analysis

Early life factors are important risk factors for breast cancer. The association between weight gain after age 18 and breast cancer risk is inconsistent across previous epidemiologic studies. To evaluate this association, we conducted a meta-analysis according to PRISMA guidelines and the established inclusion criteria. We performed a comprehensive literature search using Medline (Ovid), Embase, Scopus, Cochrane Library, and ClinicalTrials.gov to identify relevant studies published before June 3, 2022. Two reviewers independently reviewed the articles for final inclusion. Seventeen out of 4,725 unique studies met the selection criteria. The quality of studies was assessed using the Newcastle-Ottawa Scale (NOS), and all were of moderate to high quality with NOS scores ranging from 5 to 8. We included 17 studies (11 case-control, 6 cohort) in final analysis. In case-control studies, weight gain after age 18 was associated with an increased risk of breast cancer (odds ratio [OR] = 1.25; 95% CI = 1.07-1.48), when comparing the highest versus the lowest categories of weight gain. Menopausal status was a source of heterogeneity, with weight gain after age 18 associated with an increased risk of breast cancer in postmenopausal women (OR = 1.53; 95% CI = 1.40-1.68), but not in premenopausal women (OR = 1.01; 95% CI = 0.92-1.12). Additionally, a 5 kg increase in weight was positively associated with postmenopausal breast cancer risk (OR = 1.12; 95%CI = 1.05-1.21) in case-control studies. Findings from cohort studies were identical, with a positive association between weight gain after age 18 and breast cancer incidence in postmenopausal women (relative risk [RR] = 1.30; 95% CI = 1.09-1.36), but not in premenopausal women (RR = 1.06; 95% CI = 0.92-1.22). Weight gain after age 18 is a risk factor for postmenopausal breast cancer, highlighting the importance of weight control from early adulthood to reduce the incidence of postmenopausal breast cancer.

Trajectories of body mass index in adulthood and risk of subtypes of postmenopausal breast cancer

BACKGROUND

Body fatness is a dynamic exposure throughout life. To provide more insight into the association between body mass index (BMI) and postmenopausal breast cancer, we aimed to examine the age at onset, duration, intensity, and trajectories of body fatness in adulthood in relation to risk of breast cancer subtypes.

METHODS

Based on self-reported anthropometry in the prospective Norwegian Women and Cancer Study, we calculated the age at onset, duration, and intensity of overweight and obesity using linear mixed-effects models. BMI trajectories in adulthood were modeled using group-based trajectory modeling. We used Cox proportional hazards models to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for the associations between BMI exposures and breast cancer subtypes in 148,866 postmenopausal women.

RESULTS

A total of 7223 incident invasive postmenopausal breast cancer cases occurred during follow-up. Increased overweight duration and age at the onset of overweight or obesity were associated with luminal A-like breast cancer. Significant heterogeneity was observed in the association between age at overweight and overweight duration and the intrinsic-like subtypes (pheterogeneity 0.03). Compared with women who remained at normal weight throughout adulthood, women with a descending BMI trajectory had a reduced risk of luminal A-like breast cancer (HR 0.54, 95% CI 0.33-0.90), whereas women with ascending BMI trajectories were at increased risk (HR 1.09; 95% CI 1.01-1.17 for "Normal-overweight"; HR 1.20; 95% CI 1.07-1.33 for "Normal-obesity"). Overweight duration and weighted cumulative years of overweight and obesity were inversely associated with luminal B-like breast cancer.

CONCLUSIONS

In this exploratory analysis, decreasing body fatness from obesity in adulthood was inversely associated with overall, hormone receptor-positive and luminal A-like breast cancer in postmenopausal women. This study highlights the potential health benefits of reducing weight in adulthood and the health risks associated with increasing weight throughout adult life. Moreover, our data provide evidence of intrinsic-like tumor heterogeneity with regard to age at onset and duration of overweight.

The Role of Obesity in Breast Cancer Pathogenesis

Research has shown that obesity increases the risk for type 2 diabetes mellitus (Type 2 DM) by promoting insulin resistance, increases serum estrogen levels by the upregulation of aromatase, and promotes the release of reactive oxygen species (ROS) by macrophages. Increased circulating glucose has been shown to activate mammalian target of rapamycin (mTOR), a significant signaling pathway in breast cancer pathogenesis. Estrogen plays an instrumental role in estrogen-receptor-positive breast cancers. The role of ROS in breast cancer warrants continued investigation, in relation to both pathogenesis and treatment of breast cancer. We aim to review the role of obesity in breast cancer pathogenesis and novel therapies mediating obesity-associated breast cancer development. We explore the association between body mass index (BMI) and breast cancer incidence and the mechanisms by which oxidative stress modulates breast cancer pathogenesis. We discuss the role of glutathione, a ubiquitous antioxidant, in breast cancer therapy. Lastly, we review breast cancer therapies targeting mTOR signaling, leptin signaling, blood sugar reduction, and novel immunotherapy targets.

Circulating 27-hydroxycholesterol, lipids, and steroid hormones in breast cancer risk: a nested case-control study of the Multiethnic Cohort Study

BACKGROUND

Laboratory studies have indicated that a cholesterol metabolite and selective estrogen receptor modulator, 27-hydroxycholesterol (27HC), may be important in breast cancer etiology and explain associations between obesity and postmenopausal breast cancer risk. Epidemiologic evidence for 27HC in breast cancer risk is limited, particularly in multiethnic populations.

METHODS

In a nested case-control study of 1470 breast cancer cases and 1470 matched controls within the Multiethnic Cohort Study, we examined associations of pre-diagnostic circulating 27HC with breast cancer risk among African American, Japanese American, Native Hawaiian, Latino, and non-Latino White postmenopausal females. We used multivariable logistic regression adjusted for age, education, parity, body mass index, and smoking status. Stratified analyses were conducted across racial and ethnic groups, hormone receptor (HR) status, and use of lipid-lowering drugs. We assessed interactions of 27HC with steroid hormones.

RESULTS

27HC levels were inversely related to breast cancer risk (odds ratio [OR] 0.80; 95% confidence interval [CI] 0.58, 1.12), but the association was not statistically significant in the full model. Directions of associations differed by racial and ethnic group. Results suggested an inverse association with HR-negative breast cancer (OR 0.46; 95% CI 0.20, 1.06). 27HC interacted with testosterone, but not estrone, on risk of breast cancer; 27HC was only inversely associated with risk among those with the highest levels of testosterone (OR 0.46; 95% CI 0.24, 0.86).

CONCLUSION

This is the first US study to examine circulating 27HC and breast cancer risk and reports a weak inverse association that varies across racial and ethnic groups and testosterone level.

Combining machine learning with Cox models to identify predictors for incident post-menopausal breast cancer in the UK Biobank

We aimed to identify potential novel predictors for breast cancer among post-menopausal women, with pre-specified interest in the role of polygenic risk scores (PRS) for risk prediction. We utilised an analysis pipeline where machine learning was used for feature selection, prior to risk prediction by classical statistical models. An "extreme gradient boosting" (XGBoost) machine with Shapley feature-importance measures were used for feature selection among [Formula: see text] 1.7 k features in 104,313 post-menopausal women from the UK Biobank. We constructed and compared the "augmented" Cox model (incorporating the two PRS, known and novel predictors) with a "baseline" Cox model (incorporating the two PRS and known predictors) for risk prediction. Both of the two PRS were significant in the augmented Cox model ([Formula: see text]). XGBoost identified 10 novel features, among which five showed significant associations with post-menopausal breast cancer: plasma urea (HR = 0.95, 95% CI 0.92-0.98, [Formula: see text]), plasma phosphate (HR = 0.68, 95% CI 0.53-0.88, [Formula: see text]), basal metabolic rate (HR = 1.17, 95% CI 1.11-1.24, [Formula: see text]), red blood cell count (HR = 1.21, 95% CI 1.08-1.35, [Formula: see text]), and creatinine in urine (HR = 1.05, 95% CI 1.01-1.09, [Formula: see text]). Risk discrimination was maintained in the augmented Cox model, yielding C-index 0.673 vs 0.667 (baseline Cox model) with the training data and 0.665 vs 0.664 with the test data. We identified blood/urine biomarkers as potential novel predictors for post-menopausal breast cancer. Our findings provide new insights to breast cancer risk. Future research should validate novel predictors, investigate using multiple PRS and more precise anthropometry measures for better breast cancer risk prediction.

High Body Mass Index Was Associated With Human Epidermal Growth Factor Receptor 2-Positivity, Histological Grade and Disease Progression Differently by Age

Background

Breast cancer is the most commonly occurring cancer among women. The relationship between the obesity paradox and breast cancer is still unclear. The goal of this study is to elucidate the association between high body mass index (BMI) and pathological findings by age.

Methods

We collected BMI information pertinent to breast cancer patients from the Gene Expression Omnibus (GEO) database. We use a BMI of 25 as a boundary, and those greater than 25 are defined as high BMI. Besides, we segregated the patients based on age into two age groups: < 55 years, and > 55 years. In this study, R × C Chi-square for trend and binary logistic regression was used to estimate the odds ratios (ORs) and corresponding 95% confidence intervals (CIs).

Results

Higher BMI was associated with less breast cancer incidence in females younger than 55 years of age (OR = 0.313, CI: 0.240 - 0.407). High BMI was associated with human epidermal growth factor receptor 2 (HER2) positivity in breast cancer patients of less than 55 years (P < 0.001), but not in the older patients. High BMI was associated with histological grade lower than 2 in the breast cancer patients older than 55 years, but not in younger patients (OR = 0.288, CI: 0.152 - 0.544). Besides, high BMI was associated with worse progression-free survival in younger breast cancer patients, but not in older patients (P < 0.05).

Conclusions

Our results described a significant relationship between breast cancer incidence and BMI at different ages and benefit breast cancer patients to implement strategies to control their BMI for reducing the recurrence and distant recurrence.

A metabolomic analysis of adiposity measures and pre- and postmenopausal breast cancer risk in the Nurses' Health Studies

BACKGROUND

Adiposity is consistently positively associated with postmenopausal breast cancer and inversely associated with premenopausal breast cancer risk, though the reasons for this difference remain unclear.

METHODS

In this nested case-control study of 1649 breast cancer cases and 1649 matched controls from the Nurses' Health Study (NHS) and the NHSII, we selected lipid and polar metabolites correlated with BMI, waist circumference, weight change since age 18, or derived fat mass, and developed a metabolomic score for each measure using LASSO regression. Logistic regression was used to investigate the association between this score and breast cancer risk, adjusted for risk factors and stratified by menopausal status at blood draw and diagnosis.

RESULTS

Metabolite scores developed among only premenopausal or postmenopausal women were highly correlated with scores developed in all women (r = 0.93-0.96). Higher metabolomic adiposity scores were generally inversely related to breast cancer risk among premenopausal women. Among postmenopausal women, significant positive trends with risk were observed (e.g., metabolomic waist circumference score OR Q4 vs. Q1 = 1.47, 95% CI = 1.03-2.08, P-trend = 0.01).

CONCLUSIONS

Though the same metabolites represented adiposity in pre- and postmenopausal women, breast cancer risk associations differed suggesting that metabolic dysregulation may have a differential association with pre- vs. postmenopausal breast cancer.

Association of lipid profile with obesity among breast cancer survivors: a cross-sectional study

Background

The role of lipid metabolism in obesity and cancer manifestations cannot be underestimated, but whether alterations in lipid metabolism can manipulate the vasculature to promote obesity among breast cancer (BC) survivors is yet to be clearly understood. This study quantified plasma lipid and particle sizes using high-throughput proton (¹H) nuclear magnetic resonance (NMR) and tested their associations with obesity among breast cancer (BC) survivors.

Methods

A total of 348 (225 premenopausal and 123 postmenopausal) BC survivors enrolled from five hospitals in Korea were included. We assessed thirty-four plasma lipid biomarkers using ¹H NMR, and obesity status was defined as a body mass index (BMI) of 25 kg/m² or greater. Generalized linear and logistic regression models were applied to estimate the least-square means of BMI (kg/m²) and odds ratio (OR)s of obesity, respectively, and the corresponding 95% confidence interval (CI)s across plasma lipid levels.

Results

Mean (SD) values of BMI was 23.3 (3.2) kg/m² and 90 (25.9%) had BMI of ≥ 25 kg/m². BMI levels increased with increasing total triglycerides (TG), TG in lipoproteins and very-low-density lipoprotein (VLDL) subfractions. However, BMI levels decreased with increasing tertiles of high-density lipoprotein (HDL)-cholesterol (C) and HDL particle size (HDL-p). Similar associations were observed in the logistic regression models. The increasing and decreasing BMI trends with TG and HDL profiles respectively were predominantly limited to premenopausal BC survivors.

Conclusions

Increasing levels of plasma total TG and TG in lipoproteins were associated with increasing levels of BMI among premenopausal BC survivors. High HDL-C levels and large HDL-p were inversely associated with obesity among premenopausal BC survivors. Due to the cross-sectional design of this study, longitudinal studies are necessary to examine the association between obesity and lipid profile among BC survivors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01674-2.

Cellular and molecular mechanisms of breast cancer susceptibility

There is a plethora of recognized risk factors for breast cancer (BC) with poorly understood or speculative biological mechanisms. The lack of prevention options highlights the importance of understanding the mechanistic basis of cancer susceptibility and finding new targets for breast cancer prevention. Until now, we have understood risk and cancer susceptibility primarily through the application of epidemiology and assessing outcomes in large human cohorts. Relative risks are assigned to various human behaviors and conditions, but in general the associations are weak and there is little understanding of mechanism. Aging is by far the greatest risk factor for BC, and there are specific forms of inherited genetic risk that are well-understood to cause BC. We propose that bringing focus to the biology underlying these forms of risk will illuminate biological mechanisms of BC susceptibility.

Obesity and Breast Cancer Risk: The Oncogenic Implications of Metabolic Dysregulation

CONTEXT

Breast cancer is increasing in prevalence in parallel with rising rates of obesity worldwide. Obesity is recognized as a leading modifiable risk factor for the development of breast cancer; however, this association varies considerably by clinicopathologic features, and the underlying mechanisms are complex.

EVIDENCE ACQUISITION

Pubmed literature search using combinations of "obesity," "breast cancer risk," "diet," "exercise," "weight gain," "weight loss," "adipose tissue inflammation," "crown-like structure," "immune markers," "metformin," "gliflozins," "SGLT-2i," "GLP1-RA," and related terms.

EVIDENCE SYNTHESIS

Elevated body mass index and weight gain are associated with increased risk of postmenopausal, hormone receptor-positive breast cancer. Emerging evidence suggests that adverse measures of body composition in individuals of any weight can also confer increased breast cancer risk. Mechanistically, various factors including altered adipokine balance, dysfunctional adipose tissue, dysregulated insulin signaling, and chronic inflammation contribute to tumorigenesis. Weight loss and more specifically fat mass loss through lifestyle and pharmacologic interventions improve serum metabolic and inflammatory markers, sex hormone levels, and measures of breast density, suggesting a link to decreased breast cancer risk.

CONCLUSION

Incorporating markers of metabolic health and body composition measures with body mass index can capture breast cancer risk more comprehensively. Further studies of interventions targeting body fat levels are needed to curb the growing prevalence of obesity-related cancer.

Consecutive gain and loss in body weight and waist circumference with risk of subsequent breast cancer in Korean women

BACKGROUND

This study investigated the association between longitudinal changes in weight and waist circumference and breast cancer risk according to menopausal status.

METHODS

This retrospective cohort study used data from the population-based Korean National Health Insurance Service (NHI) database. The study population included women aged ≥40 years who consecutively underwent three biennial breast cancer screenings between 2009-2014 and were followed up until 2020. The percentage changes in weight and waist circumference during the three screenings were calculated and categorized into five groups based on the level of increase or decrease in these two factors. Hazard ratios (HRs) and 95% confidence intervals (95% CI) for breast cancer risk were calculated and adjusted for other factors.

RESULTS

Of 691,253 premenopausal and 1,519,211 postmenopausal women, 9485 and 12,553 breast cancer cases were identified, respectively, during a median 6.9 follow-up years. Postmenopausal women with two consecutive weight gains had an increased risk of breast cancer risk (HR = 1.11, 95% CI = 1.01 to 1.22); meanwhile, consecutive weight loss was associated with a decreased risk (HR = 0.84, 95% CI = 0.76 to 0.93). Single time and continuous decreases in waist circumference were associated with a decreased risk (HR = 0.91, 95% CI = 0.85 to 0.98, and HR = 0.84, 95% CI = 0.76-0.93), while single time and continuous increases were associated with an increased risk (HR = 1.08, 95% CI = 1.01 to 1.15, and HR = 1.13, 95% CI = 1.04 to 1.22). Single weight gain was associated with the increased breast cancer risk in premenopausal women (HR = 1.07, 95% CI = 1.01 1.13).

CONCLUSIONS

Our findings suggest a dose-response relationship between weight, waist circumference change, and the risk of future breast cancer.

Maximum and Time-Dependent Body Mass Index and Breast Cancer Incidence Among Postmenopausal Women in the Black Women's Health Study

While excess weight is an established risk factor for postmenopausal breast cancer, consideration of maximum body mass index (maxBMI; BMI is calculated as weight (kg)/height (m)2) or BMI at a point in time relevant for breast carcinogenesis may offer new insights. We prospectively evaluated maxBMI and time-dependent BMI in relation to breast cancer incidence among 31,028 postmenopausal women in the Black Women's Health Study. During 1995-2015, a total of 1,384 diagnoses occurred, including 787 estrogen-receptor (ER)-positive (ER+) cases and 310 ER-negative (ER-) cases. BMI was assessed at baseline and 2, 4, 6, and 8 years before diagnosis. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Compared with women with BMI <25, those with BMI ≥35 had increased risk of ER+ breast cancer but not ER- breast cancer. For BMI assessed 2 years before diagnosis, the HRs for ER+ breast cancer associated with maxBMI ≥35 and time-dependent BMI ≥35 were 1.42 (95% confidence interval (CI): 1.10, 1.84) and 1.63 (95% CI: 1.25, 2.13), respectively. The corresponding HR for time-dependent BMI assessed 6 years before diagnosis was 1.95 (95% CI: 1.45, 2.62). These findings suggest strong associations of BMI with risk of ER+ breast cancer in postmenopausal women, regardless of timing of BMI assessment.

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.

Obesity and Postmenopausal Hormone Receptor-positive Breast Cancer: Epidemiology and Mechanisms

Obesity is a potential risk for several cancers, including postmenopausal, hormone dependent breast cancers. In this review, we summarize recent studies on the impact of obesity on postmenopausal women's health and discuss several mechanisms that were proposed to increase the risk of breast carcinogenesis.

The Impact of the Characteristics of Exercise on The Risk of Breast Cancer Instructions

Background:

Exercise seems to protect from breast cancer (BC) and this protection is likely mediated through weight control during menopause. Considering that night work is associated with higher risk for BC.

Objective:

The aim of this study was to examine the possible relation of BC risk to daytime or nighttime hours of exercise.

Methods:

The material was taken from primary elements of a doctoral thesis at the Department of Midwifery, University of West Attica that examines the impact of the characteristics of exercising on BC. The data were obtained from relevant questionnaires filled in at a big private hospital, following a relevant permit of the scientific committee, and adjusted Google Forms, ensuring anonymity.

Results:

Almost 3 times more women without a history of BC were exclusively exercising during the daytime compared to the ones with a history of BC who were exclusively exercising during the nighttime (40 vs 15). On the contrary, a smaller number of women without a history of BC were exclusively exercising during the nighttime compared to the ones with a history of BC who were exclusively exercising during the nighttime (17 vs 20) (odds ratio >3 with a confidence interval >1 to >7.5 and p<0.05).

Conclusion:

It seems that the protective impact of exercising on BC is mitigated when the exercise is performed exclusively during night hours.

Time-Restricted Eating: A Novel and Simple Dietary Intervention for Primary and Secondary Prevention of Breast Cancer and Cardiovascular Disease

There is substantial overlap in risk factors for the pathogenesis and progression of breast cancer (BC) and cardiovascular disease (CVD), including obesity, metabolic disturbances, and chronic inflammation. These unifying features remain prevalent after a BC diagnosis and are exacerbated by BC treatment, resulting in elevated CVD risk among survivors. Thus, therapies that target these risk factors or mechanisms are likely to be effective for the prevention or progression of both conditions. In this narrative review, we propose time-restricted eating (TRE) as a simple lifestyle therapy to address many upstream causative factors associated with both BC and CVD. TRE is simple dietary strategy that typically involves the consumption of ad libitum energy intake within 8 h, followed by a 16-h fast. We describe the feasibility and safety of TRE and the available evidence for the impact of TRE on metabolic, cardiovascular, and cancer-specific health benefits. We also highlight potential solutions for overcoming barriers to adoption and adherence and areas requiring future research. In composite, we make the case for the use of TRE as a novel, safe, and feasible intervention for primary and secondary BC prevention, as well as tertiary prevention as it relates to CVD in BC survivors.

Combination of a 15-SNP Polygenic Risk Score and Classical Risk Factors for the Prediction of Breast Cancer Risk in Cypriot Women

Simple Summary

Breast cancer is the most commonly diagnosed type of cancer in women worldwide. Stratification of women based on their individual breast cancer risk could guide targeted preventative strategies and population screening. Integrated models that combine the effects of a polygenic risk score (PRS) with classical breast cancer risk factors could provide an individualized breast-cancer risk estimation. Although various studies have extensively evaluated the performance of such integrated models in populations of European ancestry, no previous studies have included individuals of Greek-Cypriot origin. To this end, we have assessed the predictive performance of a 15-SNP PRS (PRS₁₅), in combination with classical breast-cancer risk factors, in women of Greek-Cypriot origin. This proof-of-concept study suggests that models combining genetic data with classical risk factors may be used in the future for the prediction of breast-cancer risk and, therefore, supports their potential clinical utility for targeted preventative strategies in Cypriot women.

Abstract

The PRS combines multiplicatively the effects of common low-risk single nucleotide polymorphisms (SNPs) and has the potential to be used for the estimation of an individual’s risk for a trait or disease. PRS has been successfully implemented for the prediction of breast cancer risk. The combination of PRS with classical breast cancer risk factors provides a more comprehensive risk estimation and could, thus, improve risk stratification and personalized preventative strategies. In this study, we assessed the predictive performance of the combined effect of PRS₁₅ with classical breast-cancer risk factors in Cypriot women using 1109 cases and 1177 controls from the MASTOS study. The PRS₁₅ was significantly associated with an increased breast cancer risk in Cypriot women OR (95% CI) 1.66 (1.25–2.19). The integrated risk model obtained an AUC (95% CI) 0.70 (0.67–0.72) and had the ability to stratify women according to their disease status at the extreme deciles. These results provide evidence that the combination of PRS with classical risk factors may be used in the future for the stratification of Cypriot women based on their disease risk, and support its potential clinical utility for targeted preventative actions and population screening.

Association of VEGF haplotypes with breast cancer risk in North-West Indians

BACKGROUND

Angiogenesis is a complex and coordinated process regulated by different growth factors and is one of the hallmark features of cancer. VEGF is one of the most important endothelial cell mitogen and has a critical role in normal physiological and tumor angiogenesis. The objective of this study was to investigate the potential association of haplotypes of six VEGF polymorphisms with breast cancer risk in North-West Indians.

METHODS

Samples of 250 breast cancer patients and 250 age and sex matched controls were genotyped for VEGF -2578C/A, -2549I/D, -460T/C, +405C/G, -7C/T and +936C/T polymorphisms. Haplotypes were generated to determine the better contribution of VEGF polymorphisms to breast cancer risk.

RESULTS

Haplotypes CDTCCC (OR = 0.56, 95%CI, 0.38-0.81; p = 0.003) and CDTGCC (OR = 0.63, 95%CI, 0.44-0.92; p = 0.018) of VEGF -2578C/A, -2549I/D, -460T/C, +405C/G, -7C/T and +936C/T polymorphisms were significantly associated with decreased risk of breast cancer. CDTCCC haplotype was also significantly associated with reduced risk of breast cancer in pre and post menopausal as well as both obese and non obese patients. Haplotype CDTGCC was marginally associated (p = 0.07) with reduced risk of breast cancer in non-obese patients as compared with non-obese controls where as haplotype AICGTC was marginally associated (p = 0.09) with reduced risk of breast cancer in obese patients when compared with non-obese patients. The CDTGCC haplotype was significantly associated with increased risk of breast cancer in premenopausal obese patients (OR = 1.98, 95%CI, 1.10-3.56; p = 0.02).

CONCLUSIONS

Our data indicated that CDTCCC and CDTGCC haplotypes of VEGF -2578C/A, -2549I/D, -460T/C, +405C/G, -7C/T and +936C/T polymorphisms were significantly associated with breast cancer risk in North-West Indians. Further studies on multiethnic groups with larger sample size are required to confirm our results.

Central Adiposity and Subsequent Risk of Breast Cancer by Menopause Status

BACKGROUND

Increased body mass index (BMI) is associated with higher postmenopausal breast cancer risk and lower premenopausal breast cancer risk. Less is known about the central adiposity-breast cancer risk association, particularly for tumor subtypes.

METHODS

We used prospective waist (WC) and hip circumference (HC) measures in the Nurses' Health Studies. We examined associations of WC, HC, and waist-to-hip ratio (WHR) with breast cancer independent of BMI, by menopausal status. Cox proportional hazards models estimated the hazard ratios (HRs) and 95% confidence intervals (CIs) adjusting for breast cancer risk factors, with and without BMI.

RESULTS

Adjusting for BMI, WC and HC were not associated, and WHR was positively associated with premenopausal breast cancer risk (WHR, quintile 5 vs 1: HRQ5vQ1, BMI-adjusted = 1.27, 95% CI = 1.04 to 1.54; Ptrend = .01), particularly for estrogen receptor-negative (ER-) and progesterone receptor-negative (PR-) and basal-like breast cancers. Premenopausal WC, HC, and WHR were not associated with postmenopausal breast cancer risk, with or without BMI adjustment. Postmenopausal WC, HC, and WHR were each positively associated with postmenopausal breast cancer (eg, WC HRQ5vsQ1 = 1.59, 95% CI = 1.36 to 1.86); after adjustment for BMI, only WC remained statistically significant (HRQ5vsQ1, BMI-adjusted = 1.38, 95% CI = 1.15 to 1.64; Ptrend = .002). In postmenopausal women, associations were stronger among never-users of hormone therapy and for ER+/PR+ breast cancers.

CONCLUSIONS

Central adiposity was positively associated with pre- and postmenopausal breast cancers independent of BMI. This suggests that mechanisms other than estrogen may also play a role in the relationship between central adiposity and breast cancer. Maintaining a healthy waist circumference may decrease pre- and postmenopausal breast cancer risk.

Metabolic syndrome and unfavorable outcomes on body composition and in visceral adiposities indexes among early breast cancer women post-chemotherapy

PURPOSE

The study objected to investigate potential changes in metabolic, dietary, and nutritional status in women with stages I-III breast cancer exposed to chemotherapy.

METHODS

Women who were starting chemotherapy with no previous treatment were recruited. Anthropometrics, bioelectrical impedance analysis, handgrip strength, blood pressure and blood sample were collected. Visceral adiposity index and lipid accumulation product were calculated. Dietary intake was evaluated, and the multiple source methods program was applied. Metabolic syndrome (MetS) was assessed following the NCEP-ATP III criteria (defined as 3 of 5 components of MetS). All data were collected at 2-time points: diagnosis (T0) and after 1 month of completion of therapy (T1). Mean, standard deviation, percentage, and ANOVA in SAS Studio® were used to explore the results.

RESULTS

61 women were included. We did not find any changes in anthropometrics and body composition. However, phase angle, extracellular water (EX) and ratio EX to total body water had expressive changes (p < 0.001). The results showed changes in lipid profile (p < 0.001), and greater unfavorable outcomes on adiposities index (p < 0.001). At the end of the study, 68,8% (N = 42) of the women developed MetS post-chemotherapy.

CONCLUSION

We have found supporting evidence for chemotherapy treatment resulting in worsening of nutritional markers, lipid profile and adiposity markers. After chemotherapy part of the sample developed MetS, even without changes in body weight, fat mass, and food intake. Breast cancer patients may benefit from targeted interventions before starting chemotherapy to prevent MetS post-treatment, and therefore reduce the risk of cardiovascular disease. Further investigation into this theme is needed.

Contribution of the tumor and obese microenvironment to triple negative breast cancer

The growing burden of obesity and incidence of the aggressive triple negative breast cancer (TNBC) is a challenge, especially amongst vulnerable populations with unmet medical needs and higher mortality from breast cancer. While some mechanisms linking obesity and TNBC have been identified, the complex nature of pathogenesis, in both obesity as well as TNBC poses a real challenge in establishing a causative role of obesity in risk of TNBC. In this review article, we discuss pathological mechanisms identified in the tumor microenvironment (TME) as well as the obese microenvironment (OME), such as inflammation, insulin resistance and survival pathways that contribute to the development and progression of TNBC. Insights into the cross-talk between TME and OME, and their contribution to TNBC development and progression, may pave the way for personalized therapies against TNBC progression, relapse and metastasis.

Trade-Offs Between Harms and Benefits of Different Breast Cancer Screening Intervals Among Low-Risk Women

Background

A paucity of research addresses breast cancer screening strategies for women at lower-than-average breast cancer risk. The aim of this study was to examine screening harms and benefits among women aged 50-74 years at lower-than-average breast cancer risk by breast density.

Methods

Three well-established, validated Cancer Intervention and Surveillance Network models were used to estimate the lifetime benefits and harms of different screening scenarios, varying by screening interval (biennial, triennial). Breast cancer deaths averted, life-years and quality-adjusted life-years gained, false-positives, benign biopsies, and overdiagnosis were assessed by relative risk (RR) level (0.6, 0.7, 0.85, 1 [average risk]) and breast density category, for US women born in 1970.

Results

Screening benefits decreased proportionally with decreasing risk and with lower breast density. False-positives, unnecessary biopsies, and the percentage overdiagnosis also varied substantially by breast density category; false-positives and unnecessary biopsies were highest in the heterogeneously dense category. For women with fatty or scattered fibroglandular breast density and a relative risk of no more than 0.85, the additional deaths averted and life-years gained were small with biennial vs triennial screening. For these groups, undergoing 4 additional screens (screening biennially [13 screens] vs triennially [9 screens]) averted no more than 1 additional breast cancer death and gained no more than 16 life-years and no more than 10 quality-adjusted life-years per 1000 women but resulted in up to 232 more false-positives per 1000 women.

Conclusion

Triennial screening from age 50 to 74 years may be a reasonable screening strategy for women with lower-than-average breast cancer risk and fatty or scattered fibroglandular breast density.

Large-scale systematic analysis of exposure to multiple cancer risk factors and the associations between exposure patterns and cancer incidence

Exposures to cancer risk factors such as smoking and alcohol are not mutually independent. We aimed to identify risk factor exposure patterns and their associations with sociodemographic characteristics and cancer incidence. We considered 120,771 female and, separately, 100,891 male participants of the Australian prospective cohort 45 and Up Study. Factor analysis grouped 36 self-reported variables into 8 combined factors each for females (largely representing 'smoking', 'alcohol', 'vigorous exercise', 'age at childbirth', 'Menopausal Hormone Therapy', 'parity and breastfeeding', 'standing/sitting', 'fruit and vegetables') and males (largely representing 'smoking', 'alcohol', 'vigorous exercise', 'urology and health', 'moderate exercise', 'standing/sitting', 'fruit and vegetables', 'meat and BMI'). Associations with cancer incidence were investigated using multivariable logistic regression (4-8 years follow-up: 6193 females, 8749 males diagnosed with cancer). After multiple-testing correction, we identified 10 associations between combined factors and cancer incidence for females and 6 for males, of which 14 represent well-known relationships (e.g. bowel cancer: females 'smoking' factor Odds Ratio (OR) 1.16 (95% Confidence Interval (CI) 1.08-1.25), males 'smoking' factor OR 1.15 (95% CI 1.07-1.23)), providing evidence for the validity of this approach. The catalogue of associations between exposure patterns, sociodemographic characteristics, and cancer incidence can help inform design of future studies and targeted prevention programmes.

Obesity, leptin, and deregulation of microRNA in lipid metabolisms: their contribution to breast cancer prognosis

Obesity and Metabolic Syndrome have been associated with cardiovascular, diabetes and cancer incidence. Obesity is a state of inflammation. There are cross-talks between adipocyte, adipokines, pro-inflammatory cytokines, insulin, leptin, and other growth factors to initiate signals for proliferation, anti-apoptosis, and angiogenesis. Those networks lead to cancer initiation, promotion, progression, and metastasis. Post menopause women with breast cancer commonly have overweight, obesity, and metabolic syndrome, which are previously reported as conditions to be associated with breast cancer prognosis. MicroRNAs (miRNAs), small non-coding RNA that regulate gene expression, are known to play important roles either in metabolic or carcinogenesis process in patients with breast cancer. Some miRNAs expressions are deregulated in persons either with obesity, breast cancer, or breast cancer with co-morbid obesity. This literature review aimed at reviewing recent publications on the role of obesity, leptin, and microRNA deregulation in adverse prognosis of breast cancer. Understanding the influence of deregulated miRNAs and their target genes in patients with breast cancer and obesity will direct more studies to explore the potential prognostic role of obesity in breast cancer from epigenetic points of view.

Body weight management in overweight and obese breast cancer survivors

BACKGROUND

Studies suggest that overweight and obese breast cancer survivors are at increased risk of cancer recurrence and have higher all-cause mortality. Obesity has an impact on breast cancer survivor's quality of life (QOL) and increases the risk of longer-term morbidities such as type 2 diabetes mellitus and cardiovascular disease. Many cancer guidelines recommend survivors maintain a healthy weight but there is a lack of evidence regarding which weight loss method to recommend.

OBJECTIVES

To assess the effects of different body weight loss approaches in breast cancer survivors who are overweight or obese (body mass index (BMI) ≥ 25 kg/m2).

SEARCH METHODS

We carried out a search in the Cochrane Breast Cancer Group's (CBCG's) Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 6), MEDLINE (2012 to June 2019), Embase (2015 to June 2019), the World Health Organisation International Clinical Trials Registry Platform (WHO ICTRP) and Clinicaltrials.gov on 17 June 2019. We also searched Mainland Chinese academic literature databases (CNKI), VIP, Wan Fang Data and SinoMed on 25 June 2019. We screened references in relevant manuscripts.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), quasi-RCTs and randomised cross-over trials evaluating body weight management for overweight and obese breast cancer survivors (BMI ≥ 25 kg/m2). The aim of the intervention had to be weight loss.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed data extraction and assessed risk of bias for the included studies, and applied the quality of the evidence using the GRADE approach. Dichotomous outcomes were analysed as proportions using the risk ratio (RR) as the measure of effect. Continuous data were analysed as means with the measure of effect being expressed as the mean differences (MDs) between treatment groups in change from baseline values with 95% confidence intervals (CIs), when all studies reported exactly the same outcomes on the same scale. If similar outcomes were reported on different scales the standardised mean difference (SMD) was used as the measure of effect. Quality of life data and relevant biomarkers were extracted where available.

MAIN RESULTS

We included a total of 20 studies (containing 23 intervention-comparisons) and analysed 2028 randomised women. Participants in the experimental groups received weight loss interventions using the core element of dietary changes, either in isolation or in combination with other core elements such as 'diet and exercise', 'diet and psychosocial support' or 'diet, exercise and psychosocial support'. Participants in the controls groups either received usual care, written materials or placebo, or wait-list controls. The duration of interventions ranged from 0.5 months to 24 months. The duration of follow-up ranged from three months to 36 months. There were no time-to-event data available for overall survival, breast cancer recurrence and disease-free survival. There was a relatively small amount of data available for breast cancer recurrence (281 participants from 4 intervention-comparisons with 14 recurrence events; RR 1.95, 95% CI 0.68 to 5.60; low-quality evidence) and the analysis was likely underpowered. Overall, we found low-quality evidence that weight loss interventions for overweight and obese breast cancer survivors resulted in a reduction in body weight (MD: -2.25 kg, 95% CI: -3.19 to -1.3 kg; 21 intervention-comparisons; 1751 women), body mass index (BMI) (MD: -1.08 kg/m2, 95% CI: -1.61 to -0.56 kg/m2; 17 intervention-comparisons; 1353 women), and waist circumference (MD:-1.73 cm, 95% CI: -3.17 to -0.29 cm; 13 intervention-comparisons; 1193 women), and improved overall quality of life (SMD: 0.74; 95% CI: 0.20 to 1.29; 10 intervention-comparisons; 867 women). No increase was seen in adverse events for women in the intervention groups compared to controls (RR 0.94, 95% CI: 0.76 to 1.17; 4 intervention-comparisons; 394 women; high-quality evidence). Subgroup analyses revealed that decreases in body weight, BMI and waist circumference were present in women regardless of their ethnicity and menopausal status. Multimodal weight loss interventions (which referred to 'diet, exercise and psychosocial support') appeared to result in greater reductions in body weight (MD: -2.88 kg, 95% CI: -3.98 to -1.77 kg; 13 intervention-comparisons; 1526 participants), BMI (MD: -1.44 kg/m2, 95% CI: -2.16 to -0.72 kg/m2; 11 studies; 1187 participants) and waist circumference (MD:-1.66 cm, 95% CI: -3.49 to -0.16 cm; 8 intervention-comparisons; 1021 participants) compared to dietary change alone, however the evidence was low quality.

AUTHORS' CONCLUSIONS

Weight loss interventions, particularly multimodal interventions (incorporating diet, exercise and psychosocial support), in overweight or obese breast cancer survivors appear to result in decreases in body weight, BMI and waist circumference and improvement in overall quality of life. There was no increase in adverse events. There is a lack of data to determine the impact of weight loss interventions on survival or breast cancer recurrence. This review is based on studies with marked heterogeneity regarding weight loss interventions. Due to the methods used in included studies, there was a high risk of bias regarding blinding of participants and assessors. Further research is required to determine the optimal weight loss intervention and assess the impact of weight loss on survival outcomes. Long-term follow-up in weight loss intervention studies is required to determine if weight changes are sustained beyond the intervention periods.

Impact of BMI on HER2+ metastatic breast cancer patients treated with pertuzumab and/or trastuzumab emtansine. Real-world evidence

Body mass index (BMI) is a main indicator of obesity and its association with breast cancer is well established. However, little is known in the metastatic setting, especially in HER2-positive patients. We assessed the influence of BMI on clinical outcomes of patients treated with pertuzumab and/or trastuzumab emtansine (T-DM1) for HER2+ metastatic breast cancer (mBC). BMI was addressed as a categorical variable, being classified on the basis of the following ranges, that is, 18.5-24.9, 25-29.9, and 30.0-34.9, namely, normal weight, overweight, and Class I obesity. The outcomes chosen were progression-free survival to first-line chemotherapy (PFS1) and overall survival (OS). Overall (N = 709), no impact of BMI was observed on PFS1 (p = .15), while BMI ≥ 30 was associated with worse OS (p = .003). In subjects who progressed to first line (N = 575), analyzing data across PFS1 quartiles and strata of disease burden, BMI predicted lower PFS1 in patients within the I PFS1 quartile and with the lowest disease burden (p = .001). Univariate analysis showed a detrimental effect of BMI ≥ 30 on OS for women within the I PFS1 quartile (p = .03). Results were confirmed in multivariate analysis. According to PFS1 quartiles a higher percentage of patients with high BMI and low disease burden progressed within 6 months of therapy. The effect of BMI on prognosis was also confirmed in multivariate analysis of OS for overall population. In our cohort, a BMI ≥ 30 correlated with worse OS in patients with HER2+ mBC who received pertuzumab and/or T-DM1 but had no impact on PFS to first line. BMI predicted worse I PFS1 quartile.

Interactions Between Food and Gut Microbiota: Impact on Human Health

Understanding the relationship between food and the gut microbiota, their interactions, and how each modulates the other is critical for successful promotion of human health. This review seeks to summarize ( a) the current knowledge on the effects of food and food components on gut microbiota and ( b) the association between gut microbiota, consumption of food, and food bioactive components and the resulting beneficial health outcomes. Our goal is to provide state-of-the-art information on food and gut microbiota interactions and to stimulate discussions and research approaches that will move the field forward.

Construction and Validation of Breast Cancer Awareness Scale in Iranian Women

Introduction: Application of a single valid and reliable questionnaire in future studies in the area of Iranian women's awareness of breast cancer provides the health policymakers with a comprehensive view over the issue. In designing the current questionnaires in Iran, the prior researchers neither explained about the design procedure, nor calculated the validity and reliability of the questionnaire completely. In this regard, researchers decided to design a standard questionnaire to examine women's awareness about the symptoms and risk factors of the breast cancer. Methods: This methodological study was conducted on 250 women in Yazd. Data were collected by a researcher-made questionnaire. The reliability was determined using the Cronbach's alpha and test-retest method. Factor analysis was used to determine the construct validity in SPSS version 21. Results: The face validity of the questionnaire was evaluated by the target population. The results of the impact score indicated that all questions had a score equal or greater than 1.5. The qualitative content validity of the questionnaire was evaluated by the expert panel. Content validity ratio (CVR) and content validity index (CVI) obtained close to one for questionnaire. Construct validity was confirmed by performing factor analysis and dimensions of the questionnaire were determined. Cronbach's alpha coefficient for all dimensions was higher than 0.8. Also, intraclass correlation coefficient (ICC) for all dimensions was close to one and was between 0.84-0.95. Conclusion: Validity and reliability of designed questionnaire in this study for Iranian women are acceptable and suitable.

The Relationship Between White Adipose Tissue Inflammation and Overweight/Obesity in Chinese Female Breast Cancer: A Retrospective Study

INTRODUCTION

This study aims to investigate the relationship between breast white adipose tissue (WAT) inflammation and being overweight or obese, menopausal status, and metabolic syndrome-related indicators in breast cancer patients as well as the association between adipocyte size and the severity of WAT inflammation and body mass index (BMI).

METHODS

The crown-like structures (CLS-B) formed by macrophages surrounding dying or dead adipocytes can be used to identify breast WAT inflammation. In this study, breast WAT and fasting blood from 136 Chinese women with breast cancer were collected for analysis. Cluster of differentiation 68 (CD68) immunohistochemical staining was performed to identify CLS-B, and the adipocyte size was measured by hematoxylin and eosin staining.

RESULTS

The results showed that breast WAT inflammation usually occurs in overweight/obese breast cancer patients, and the severity of inflammation is positively correlated with adipocyte hypertrophy. We did not observe a direct association between WAT inflammation and menopausal status. In addition, the presence of WAT inflammation is associated with abnormalities in circulating factors associated with metabolic syndrome such as higher serum lipid, glucose, and C-reactive protein levels.

CONCLUSION

Overweight/obese breast cancer patients may be more prone to breast WAT inflammation and may be associated with abnormalities in circulatory markers associated with metabolic syndrome.

Investigation of the association between metabolic syndrome and breast cancer patients

One of the most serious cancers among women is breast cancer. This disease is the first reason for the death of women due to cancer. Increasing breast cancer risk may associate with many factors including genetic, reproductive factors, people's lifestyle, metabolic syndrome (MS) and hormones. MS has been known as a risk factor for prostate, pancreatic, breast and colorectal cancers. The purpose of this review is to identify the relationship between MS components and breast cancer individually. This study was performed by researching electronic database references including PubMed, Google Scholar, CINAHL ProQuest, and web of science through 2019. The effect of MS with its components and breast cancer was reported in many studies. Nevertheless, a thorough understanding of the mechanisms involved remains a challenge. However, one can take several preventive measures, including a proper diet, which is one of the most important determinants of metabolic status. Also, general preventive recommendations are including reducing alcohol consumption, red meat and total fat in the diet. Moreover, increasing the consumption of vegetable and fruit reduce the proportion of MS patients to improve the outcome of breast cancer patients.

Relationship Between Metabolic Syndrome and Postmenopausal Breast Cancer

INTRODUCTION

Metabolic syndrome is associated with an increased risk of diabetes mellitus (DM) and coronary heart disease. It may also be associated with a higher risk of some common cancers. The objective of this study was to determine the relationship between metabolic syndrome and breast cancer in postmenopausal women.

METHODS

We present a prospective cohort study of postmenopausal women. This cohort was divided into two groups: the «benign diagnosis group», including women who were studied after breast cancer screening; and the «malignant tumor group», including patients with breast cancer that had been diagnosed by biopsy. Age, weight, height, body mass index (BMI), abdominal perimeter, serum glucose, LDL, HDL and insulin levels were analyzed as variables under study. The HOMA-IR homeostatic model formula was used to assess insulin resistance. The differences were considered statistically significant when P<.05.

RESULTS

Two hundred women with a mean age of 61.5±9.6 (range: 37-93) were enrolled in the study, consisting of 150 (75%) patients with a benign diagnosis and 50 (25%) patients with a malignant tumor. BMI and abdominal perimeter were higher in the group with a malignant tumor (P<.05). The incidence of DM and metabolic syndrome was higher in the malignant tumor group (P<.005). In the malignant tumor group, much higher incidences correlated with fasting glycemic levels >100mg/dL, insulin levels >10mIU/L and HOMA-IR scores >2.7 (P<.05).

CONCLUSIONS

There is a relationship between metabolic syndrome and postmenopausal breast cancer. More studies are needed to establish methods for the prevention of breast cancer in women with metabolic syndrome.

Impact of BMI for clinical outcomes in Japanese breast cancer patients

OBJECTIVE

The relationship between the body mass index (BMI) at the time of breast cancer diagnosis and the prognosis of breast cancer patients has not yet been clarified. We investigated the impact of obesity for clinical outcomes in Japanese breast cancer patients.

METHODS

Women with primary breast cancer operated between 2002 and 2014 were identified. All patients are categorized into four groups according to BMI. The range of BMI is <18.5 kg/m2, from 18.5 to 24.9 kg/m2, 25 to 29.9 kg/m2, >30 kg/m2 in underweight, normal, overweight and obesity groups, respectively. The correlation between BMI and overall survival (OS), breast cancer-specific survival (BCSS) and disease-free survival (DFS) were statistically analyzed.

RESULTS

From the database of our institution, we identified 3223 patients. The median follow-up period was 57 months (1-149). We categorized 2257 (70.0%), 318 (9.9%), 545 (16.9%) and 103 (3.2%) patients into normal, underweight, overweight obesity groups respectively. There were189 patients (5.9%) deaths due to breast cancer recurrence (137 patients) and other disease (52 patients). Obesity groups was significantly high compared with normal groups for OS (adjusted HR, 2.43; 95% CI, 1.38-4.28; P < 0.001), BCSS (adjusted HR, 2.73; 95% CI, 1.15-6.44; P = 0.02) and DFS (adjusted HR, 1.83; 95% CI, 1.11-3.02; P = 0.017) by multivariate analysis. Especially, OS (adjusted HR, 4.87; 95% CI, 2.15-11.04; P < 0.001), BCSS (adjusted HR, 4.51; 95% CI, 1.52-13.34; P < 0.001) and DFS (adjusted HR, 4.87; 95% CI, 1.02-4.89; P = 0.04) were statistically insignificant in postmenopausal ER-positive breast cancer patients.

CONCLUSION

Obesity might be risk factor for OS, BCSS and DFS, especially postmenopausal ER-positive women.

The impact of patient characteristics and lifestyle factors on the risk of an ipsilateral event after a primary DCIS: A systematic review

Objective

The majority of ‘low-risk’ (grade I/II) Ductal Carcinoma In Situ (DCIS) may not progress to invasive breast cancer during a women’s lifetime. Therefore, the safety of active surveillance versus standard surgical treatment for DCIS is prospectively being evaluated in clinical trials. If proven safe and selectively implemented in clinical practice, a significant group of women with low-risk DCIS may forego surgery and radiotherapy in the future. Identification of modifiable and non-modifiable risk factors associated with prognosis after a primary DCIS would also enhance our care of women with low-risk DCIS.

Methods

To identify modifiable and non-modifiable risk factors for subsequent breast events after DCIS, we performed a systematic literature search in PUBMED, EMBASE and Scopus.

Results

Six out of the 3870 articles retrieved were included for final data extraction. These six studies included a total of 4950 patients with primary DCIS and 640 recorded subsequent breast events. There was moderate evidence for an association of a family history of breast cancer, premenopausal status, high BMI, and high breast density with a subsequent breast cancer or further DCIS.

Conclusion

There is a limited number of recent studies published on the impact of modifiable and non-modifiable risk factors on subsequent events after DCIS. The available evidence is insufficient to identify potential targets for risk reduction strategies, reflecting the relatively small numbers and the lack of long-term follow-up in DCIS, a low-event condition.

•

Need for risk management strategies for untreated DCIS patients.

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Limited evidence for association between lifestyle factors and prognosis after DCIS.

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Positive family history, premenopausal status, high breast density associated with prognosis.

Anthropometric measures of body fat and obesity-related cancer risk: sex-specific differences in Framingham Offspring Study adults

BACKGROUND/OBJECTIVE

Obesity has been associated with the risk of developing certain cancers. A limited number of studies have examined effects of various anthropometric measures of body composition on cancer risk. The aim of this study was to estimate the sex-specific effects of various anthropometric measures on risk of obesity-related cancers (ObCa).

SUBJECTS/METHODS

Data on body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), and hip circumference (HC) among 3818 45-69-year olds in the Framingham Offspring Study were included. Cox proportional hazards models were used to estimate adjusted risks of 16 obesity-related cancers, with the most common being postmenopausal breast, endometrial, and colon cancers.

RESULTS

Obesity as measured by BMI in both men and women was a predictor of ObCa; those in the highest quintile (Q5) of BMI (>30.07 in women; >30.80 kg/m² in men) had more than twice the risk of ObCa (HR = 2.07; 95% CI: 1.06-4.07 (women) and HR = 2.25; 95% CI: 1.08-4.69 (men)). Waist-related measures (WC, WHtR) were stronger predictors of ObCa in men than in women, and HC confounded the relations between waist size and cancer risk. After adjusting for HC, men in Q5 of WC had more than a threefold increased risk of ObCa (HR: = 3.22; 95% CI: 1.39-7.45). Comparable effects in women were weak and non-statistically significant. Results were similar for WHtR. Finally, an inverse J-shaped relation was found between HC and ObCa after adjusting for WC among men but not in women.

CONCLUSIONS

These results suggest that obesity as measured by BMI is a predictor of obesity-related cancer risk in men and women. They also suggest that waist and hip circumference measures are interrelated and confound the independent effects of each measure. Among men, a large waist size and a small hip size are independent predictors of cancer risk.

Waist Circumference and Risk of Liver Cancer: A Systematic Review and Meta-Analysis of over 2 Million Cohort Study Participants

PURPOSE

Liver cancer is the sixth most common type of cancer worldwide, and waist circumference (WC) is associated with its risk beyond body mass index (BMI). This dose-response meta-analysis was performed to investigate the association between WC and the risk of incident liver cancer using prospective cohort studies.

METHODS

A comprehensive systematic search was conducted in MEDLINE/PubMed, Web of Science databases, Scopus, and Coch-rane from inception to May 2019. Studies with retrospective or prospective cohort design that reported hazard ratio (HR), risk ratio, or odds ratio, and the corresponding 95% confidence intervals (CI) for liver cancer based on WC categories were included in this meta-analysis. Combined HRs with 95% CIs was estimated by DerSimonian and Laird random-effects models.

RESULTS

Associations between WC and liver cancer were reported in 5 articles with 2,547,188 participants. All studies were published between 2013 and 2019. Pooled results showed a strong significant association with minimum heterogeneity between WC and risk of liver cancer (HR 1.59, 95% CI 1.38-1.83, p_{heterogeneity} = 0.42: I² = 0%). Moreover, a dose-response model indicated a significant positive association between WC and risk of liver cancer (exp(b) = 1.018, p < 0.001).

CONCLUSIONS

This systematic review and dose-response meta-analysis highlights WC as a significant risk factor related to the incidence of liver cancer.