Effect of obesity on prognosis after early-stage breast cancer

Nutritional assessment of female patients newly diagnosed with breast cancer in a northern region of Spain

Introduction

Background: evidence from research suggests that the development of cancer disease is associated with environmental factors. There are few studies evaluating nutritional status in women suffering from cancer in Spain. Objectives: this study aimed to assess the nutritional status in breast cancer female patients at diagnosis in a northern region of Spain (Asturias), where breast cancer rates are particularly high when compared to the rest of Spain. Material and methods: a cross-sectional study was conducted in a sample of 76 newly diagnosed female cancer patients. Lifestyle factors, anthropometry, biochemical, and dietary intake data were collected immediately after diagnosis and prior to the initiation of the prescribed treatment. Results: a high percentage of these women diagnosed with cancer were sedentary (59.2%). Their average body mass index (BMI) was 27.3 ± 5.5 kg/m2. They also showed a high percentage of body fat, 38.3%, as well as a large waist circumference of 92.2 cm. Patients reported a low intake of fruits, vegetables, legumes, and nuts, and a high intake of red meat, meat products, and sweet foodstuffs as compared to the Spanish dietary guidelines (p < 0.01). Conclusion: the results showed a low intake of folate, calcium, and vitamin D, which is particularly relevant in women. In conclusion, these breast cancer patients showed overweight and high sedentarism levels, and reported unbalanced dietary patterns at the time of diagnosis.

Body Mass Index and Outcomes in Breast Cancer Treated With Breast Conservation

PURPOSE

Obesity is increasing in incidence in New Zealand. Maintaining locoregional control after breast cancer surgery is important, as this can improve overall survival. Although obesity has been associated with poorer survival in breast cancer, the correlation with locoregional control is less well evaluated and was the subject of this evaluation.

METHODS AND MATERIALS

We used the New Zealand breast cancer registry to identify patients treated with breast conservation with body mass index (BMI) recorded. We retrieved patient demographic, tumor characteristic, and treatment-related information. We assessed local and locoregional control outcomes in addition to breast cancer and overall survival outcomes.

RESULTS

Patients (2513) were identified. The median follow-up was 5.25 years. Of these patients, 38% were obese with a BMI of ≥30 kg/m², 32% were overweight with a BMI of 25.0 to 29.9 kg/m², and 29% were either normal or underweight with a BMI of ≤24.9 kg/m². Most patients were postmenopausal (65%). The median tumor size was 16.0 mm (0.2-80 mm) and the majority were grade 2 or 3 tumors (45% and 33%). The majority (66%) were pathologically node negative and lymphovascular invasion was seen in 24%. There were 81% with estrogen receptor positivity and 358 (14.2%) were Her-2 positive. Local relapse free survival at 5 years was 91.5% (95% confidence interval [CI], 90.3-92.7) and at 10 years was 78.5% (95% CI, 75.9-81.1). Local relapse free rate at 5 years was 96.8% (95% CI, 96.0-97.6) and 10 years was 93.9% (95% CI, 92.5-95.3). We did not find BMI to be associated with local or locoregional relapse, disease free, breast cancer specific, or overall survival.

CONCLUSIONS

Obesity was not associated with inferior locoregional control or survival outcomes. This supports the practice of continuing to offer breast conserving treatment to women regardless of BMI.

Breast Cancer Stem Cells as Drivers of Tumor Chemoresistance, Dormancy and Relapse: New Challenges and Therapeutic Opportunities

Breast cancer is the most frequent cancer among women worldwide. Therapeutic strategies to prevent or treat metastatic disease are still inadequate although great progress has been made in treating early-stage breast cancer. Cancer stem-like cells (CSCs) that are endowed with high plasticity and self-renewal properties have been shown to play a key role in breast cancer development, progression, and metastasis. A subpopulation of CSCs that combines tumor-initiating capacity and a dormant/quiescent/slow cycling status is present throughout the clinical history of breast cancer patients. Dormant/quiescent/slow cycling CSCs are a key component of tumor heterogeneity and they are responsible for chemoresistance, tumor migration, and metastatic dormancy, defined as the ability of CSCs to survive in target organs and generate metastasis up to two decades after diagnosis. Understanding the strategies that are used by CSCs to resist conventional and targeted therapies, to interact with their niche, to escape immune surveillance, and finally to awaken from dormancy is of key importance to prevent and treat metastatic cancer. This review summarizes the current understanding of mechanisms involved in CSCs chemoresistance, dissemination, and metastasis in breast cancer, with a particular focus on dormant cells. Finally, we discuss how advancements in the detection, molecular understanding, and targeting of dormant CSCs will likely open new therapeutic avenues for breast cancer treatment.

Obesity and survival among a cohort of breast cancer patients is partially mediated by tumor characteristics

Obesity exerts adverse effects on breast cancer survival, but the means have not been fully elucidated. We evaluated obesity as a contributor to breast cancer survival according to tumor molecular subtypes in a population-based case-cohort study using data from the Surveillance Epidemiology and End Results (SEER) program. We determined whether obese women were more likely to be diagnosed with poor prognosis tumor characteristics and quantified the contribution of obesity to survival. Hazard ratios (HRs) and 95% confidence intervals (CI) were calculated via Cox multivariate models. The effect of obesity on survival was evaluated among 859 incident breast cancers (subcohort; 15% random sample; median survival 7.8 years) and 697 deaths from breast cancer (cases; 100% sample). Obese women had a 1.7- and 1.8-fold increased risk of stage III/IV disease and grade 3/4 tumors, respectively. Obese women with Luminal A- and Luminal B-like breast cancer were 1.8 (95% CI 1.3-2.5) and 2.2 (95% CI 0.9-5.0) times more likely to die from their cancer compared to normal weight women. In mediation analyses, the proportion of excess mortality attributable to tumor characteristics was 36.1% overall and 41% and 38% for Luminal A- and Luminal B-like disease, respectively. Obesity was not associated with breast cancer-specific mortality among women who had Her2-overexpressing or triple-negative tumors. Obesity may influence hormone-positive breast cancer-specific mortality in part through fostering poor prognosis tumors. When tumor biology is considered as part of the causal pathway, the public health impact of obesity on breast cancer survival may be greater than previously estimated.

Glitazone loaded fat enhances adiponectin production and inhibits breast cancer cell proliferation

Obesity and diabetes are both associated risk factors for developing breast cancer and poor patient outcomes. Adipose cells are an important endocrine system and are the main producer of adiponectin, with lean patients having higher circulating levels. Patients with diabetes are often treated with thiazolidinediones, glitazones, which also increase adiponectin production. Importantly high circulating levels of adiponectin and treatment with glitazone are associated with increased breast cancer patient survival. This study investigates the potential of using adipose tissue laden with glitazones to act as a drug depot, increase adiponectin levels, and locally release glitazones to inhibit breast cancer cell proliferation. The breast cancer cell lines MCF-7 and MBA-MD-231, and the normal breast epithelial cell line MCF-10A were exposed to media containing a range of concentrations of recombinant adiponectin, pioglitazone, or conditioned media obtained from pioglitazone laden adipose tissue to determine the impact of the different treatments on cell proliferation. The MCF-7 cells demonstrated the greatest reduction in proliferation upon exposure to adiponectin and pioglitazone with lower reductions observed in the MDA-MD-231 and MCF-10a cell lines. All three cell lines exhibited reductions in proliferation in the presence of pioglitazone loaded adipose tissue. Additionally, adiponectin and pioglitazone levels were higher in the media from glitazone loaded adipose tissue. Drug loaded adipose tissue could potentially be used to deliver adiponectin and glitazone to breast cancer cells and inhibit proliferation. Future research will examine the potential efficacy of this treatment approach in vivo.

Obesity and psychosocial well-being among cancer patients and survivors

OBJECTIVE

As the association between obesity and cancer receives increasing attention, studies have begun to examine the potential impact of excess weight on psychosocial domains during treatment and survivorship. The current study will examine the effect of weight status on psychosocial outcomes among patients diagnosed with breast cancer, prostate cancer, and colon cancer.

METHODS

This retrospective study included 4159 patients over the age of 55 who were diagnosed with postmenopausal breast (52.2%), prostate (38.7%), or colon cancer (9.1%). Prior to treatment, patients were screened for problem-related distress using a 33-item touch screen-based instrument. Descriptive statistics were generated for each cancer type and one-way analysis of covariance (ANCOVA) used to determine significant differences in distress by weight (nonobese: <30 kg/m² vs obese: ≥30 kg/m² ).

RESULTS

A higher prevalence of biopsychosocial problem-related distress was reported by patients with breast cancer (M = 4.3) compared with prostate (M = 2.8) and colon cancer (M = 3.8). Obese breast and prostate cancer patients reported higher levels of problem-related distress compared with nonobese patients (P < .05), whereas an opposite trend was noted for patients with colon cancer.

CONCLUSION

The current study found notable obesity-related differences among patients diagnosed with postmenopausal breast cancer or prostate cancer, with excess weight consistently associated with poorer psychosocial outcomes. These findings among a large cohort of patients provide insight into the impact of obesity during the cancer care trajectory and can provide guidance in the development and implementation of supportive care services for this "at-risk" population.

The weight of obesity in breast cancer progression and metastasis: Clinical and molecular perspectives

The escalating epidemic of overweight and obesity is currently recognized as one of the most significant health and economic concern worldwide. At the present time, over 1.9 billion adults and more than 600 million people can be, respectively, classified as overweight or obese, and numbers will continue to increase in the coming decades. This alarming scenario implies important clinical implications since excessive adiposity can progressively cause and/or exacerbate a wide spectrum of co-morbidities, including type 2 diabetes mellitus, hypertension, cardiovascular disease, and even certain types of cancer, including breast cancer. Indeed, pathological remodelling of white adipose tissue and increased levels of fat-specific cytokines (mainly leptin), as a consequence of the obesity condition, have been associated with several hallmarks of breast cancer, such as sustained proliferative signaling, cellular energetics, inflammation, angiogenesis, activating invasion and metastasis. Different preclinical and clinical data have provided evidence indicating that obesity may worsen the incidence, the severity, and the mortality of breast cancer. In the present review, we will discuss the epidemiological connection between obesity and breast cancer progression and metastasis and we will highlight the candidate players involved in this dangerous relationship. Since the major cause of death from cancer is due to widespread metastases, understanding these complex mechanisms will provide insights for establishing new therapeutic interventions to prevent/blunt the effects of obesity and thwart breast tumor progression and metastatic growth.

Metastasis as a systemic disease: molecular insights and clinical implications

Metastasis is a complex systemic disease that develops as a result of interactions between tumor cells and their local and distant microenvironments. Local and systemic immune-related changes play especially critical roles in limiting or enabling the development of metastatic disease. Although anti-tumor immune responses likely eliminate most early primary and metastatic lesions, factors secreted by cancer or stromal cells in the primary tumor can mobilize and activate cells in distant organs in a way that promotes the outgrowth of disseminated cancer cells into macrometastatic lesions. Therefore, the prevention, detection, and effective treatment of metastatic disease require a deeper understanding of the systemic effects of primary tumors as well as predisposing hereditary and acquired host factors including chronic inflammatory conditions. The success of immunotherapy in a subset of cancer patients is an example of how modulating the microenvironment and tumor-immune cell interactions can be exploited for the effective eradiation of even advanced-stage tumors. Here, we highlight emerging insights and clinical implications of cancer as a systemic disease.

Obesity and the Effects of Weight Reduction: A Spotlight on Women with Hormone Receptor-Positive Breast Cancer and Heart Disease

Obesity is a common overlapping risk factor for cancer and cardiovascular disease (CVD), and the long-term consequences of these chronic, interconnected diseases are severe. The importance of CVD in breast cancer (BC) patients and survivors has been well-established, and the potential impact of some BC treatments (such as cardiotoxic effects related to chemotherapy or targeted therapy with the use of doxorubicin or trastuzumab, and radiation therapy, especially in cases of left breast tumours) on the cardiovascular condition necessitates ongoing cardiological surveillance. In addition, the possible reduction of some underlying risk factors is critical to long-term protection of BC patients and survivors. The concept of obesity dynamically interacting with both BC and CVD is important because it is a modifiable risk factor, and the modern management of obesity deserves emphasis. In particular, for many BC patients and survivors, an effective weight reduction programme integrated with standard anticancer and cardiology therapies can improve patient outcomes. This review presents the complex relationships between overweight, obesity, CVD, and BC risk and highlights outcomes in post and premenopausal women, focussing on patients with hormone receptor-positive BC. The review provides evidence from epidemiologic, observational, and weight loss intervention trials which have examined the effects of weight reduction programmes on BC outcomes. Such studies have indicated that moderate weight loss, with regular physical exercises or stress reduction, can significantly improve BC outcomes. Future lifestyle intervention trials could support the incorporation of weight loss interventions as an integral element of comprehensive management for BC patients and survivors.

Preexisting Commensal Dysbiosis Is a Host-Intrinsic Regulator of Tissue Inflammation and Tumor Cell Dissemination in Hormone Receptor-Positive Breast Cancer

It is unknown why some patients with hormone receptor-positive (HR⁺) breast cancer present with more aggressive and invasive disease. Metastatic dissemination occurs early in disease and is facilitated by cross-talk between the tumor and tissue environment, suggesting that undefined host-intrinsic factors enhance early dissemination and the probability of developing metastatic disease. Here, we have identified commensal dysbiosis as a host-intrinsic factor associated with metastatic dissemination. Using a mouse model of HR⁺ mammary cancer, we demonstrate that a preestablished disruption of commensal homeostasis results in enhanced circulating tumor cells and subsequent dissemination to the tumor-draining lymph nodes and lungs. Commensal dysbiosis promoted early inflammation within the mammary gland that was sustained during HR⁺ mammary tumor progression. Furthermore, dysbiosis enhanced fibrosis and collagen deposition both systemically and locally within the tumor microenvironment and induced significant myeloid infiltration into the mammary gland and breast tumor. These effects were recapitulated both by directly targeting gut microbes using nonabsorbable antibiotics and by fecal microbiota transplantation of dysbiotic cecal contents, demonstrating the direct impact of gut dysbiosis on mammary tumor dissemination. This study identifies dysbiosis as a preexisting, host-intrinsic regulator of tissue inflammation, myeloid recruitment, fibrosis, and dissemination of tumor cells in HR⁺ breast cancer. SIGNIFICANCE: Identification of commensal dysbiosis as a host-intrinsic factor mediating evolution of metastatic breast cancer allows for development of interventions or diagnostic tools for patients at highest risk for developing metastatic disease.See related commentary by Ingman, p. 3539.

Prognostic role of body mass index is different according to menopausal status and tumor subtype in breast cancer patients

PURPOSE

Although controversial, obesity and underweight may have a negative impact on breast cancer outcome. However, the relationship between body mass index (BMI) and breast cancer outcomes according to tumor subtype and menopausal status remains unclear.

METHODS

This study investigated the association between BMI and breast cancer outcome in stage I-III breast cancer patients. The relationships were further evaluated according to tumor subtype and menopausal status.

RESULTS

A total of 5919 patients, 3475 (58.7%) hormone receptor (HR)(+) human epidermal growth factor receptor 2 (HER2)(-), 608 (10.3%) HR(+)HER2(+), 621 (10.5%) HR(-)HER2(+), and 1079 (18.2%) HR(-)HER2(-) were included. Underweight and obesity had a negative impact on relapse-free survival but did not affect overall survival. Importantly, the prognostic role of BMI was different according to tumor subtype and menopausal status. In HR(+)HER2(-) patients, underweight was associated with poor relapse-free survival and overall survival in pre-menopausal women. In contrast, obesity had negative impact on relapse-free survival and overall survival in HR(+)HER2(-) post-menopausal patients. Underweight may have a negative prognostic role in HR(+)HER2(+) patients. However, BMI did not impact the outcome of HR(-)HER2(+) and HR(-)HER2(-) patients.

CONCLUSIONS

The impact of BMI on breast cancer outcome was dependent on tumor subtype and menopausal status. In HR(+)HER2(-) patients, underweight and obesity had a negative prognostic role in pre-menopausal and post-menopausal women, respectively. These findings in Asian population should be further evaluated and compared in Western population.

Obesity-induced MBD2_v2 expression promotes tumor-initiating triple-negative breast cancer stem cells

Obesity is a risk factor for triple-negative breast cancer (TNBC) incidence and poor outcomes, but the underlying molecular biology remains unknown. We previously identified in TNBC cell cultures that expression of epigenetic reader methyl-CpG-binding domain protein 2 (MBD2), specifically the alternative mRNA splicing variant MBD variant 2 (MBD2_v2), is dependent on reactive oxygen species (ROS) and is crucial for maintenance and expansion of cancer stem cell-like cells (CSCs). Because obesity is coupled with inflammation and ROS, we hypothesized that obesity can fuel an increase in MBD2_v2 expression to promote the tumor-initiating CSC phenotype in TNBC cells in vivo. Analysis of TNBC patient datasets revealed associations between high tumor MBD2_v2 expression and high relapse rates and high body mass index (BMI). Stable gene knockdown/overexpression methods were applied to TNBC cell lines to elucidate that MBD2_v2 expression is governed by ROS-dependent expression of serine- and arginine-rich splicing factor 2 (SRSF2). We employed a diet-induced obesity (DIO) mouse model that mimics human obesity to investigate whether obesity causes increased MBD2_v2 expression and increased tumor initiation capacity in inoculated TNBC cell lines. MBD2_v2 and SRSF2 levels were increased in TNBC cell line-derived tumors that formed more frequently in DIO mice relative to tumors in lean control mice. Stable MBD2_v2 overexpression increased the CSC fraction in culture and increased TNBC cell line tumor initiation capacity in vivo. SRSF2 knockdown resulted in decreased MBD2_v2 expression, decreased CSCs in TNBC cell cultures, and hindered tumor formation in vivo. This report describes evidence to support the conclusion that MBD2_v2 expression is induced by obesity and drives TNBC cell tumorigenicity, and thus provides molecular insights into support of the epidemiological evidence that obesity is a risk factor for TNBC. The majority of TNBC patients are obese and rising obesity rates threaten to further increase the burden of obesity-linked cancers, which reinforces the relevance of this report.

The Impact of Obesity on Breast Cancer Diagnosis and Treatment

Purpose of Review

Obesity is a recognized risk factor for the development of breast cancer and recurrence even when patients are treated appropriately. We reviewed the literature that addresses the impact of obesity on diagnosis and the individual therapeutic interventions, and present a summary of the findings.

Recent Findings

Compared to non-obese women with breast cancer, obese women with breast cancer have a worse disease-free and overall survival despite appropriate local and systemic therapies. In brief, obese breast cancer patients experience more complications related to surgery, radiation, and chemotherapy. Further, obese patients are at increased risk for local recurrence compared to normal-weight women. Similarly, systemic chemotherapy is less effective, even when dosed appropriately on the basis of actual weight. Overall, endocrine therapy is less effective in obese women, and there is a suggestion that aromatase inhibitors may be selectively less effective than tamoxifen. Obese women are less likely to undergo breast reconstruction than normal-weight women, and those who do have surgery experience more surgical complications.

Summary

The efficacy of cancer treatments is significantly lower in obese breast cancer survivors, posing greater challenges in patient care and disease management in this patient population. Further investigations are warranted to assess the effects on treatment outcomes and optimize therapeutic mechanisms in order to successfully target breast cancer associated with obesity.

Impact of obesity on breast cancer recurrence and minimal residual disease

BACKGROUND

Obesity is associated with an increased risk of breast cancer recurrence and cancer death. Recurrent cancers arise from the pool of residual tumor cells, or minimal residual disease (MRD), that survives primary treatment and persists in the host. Whether the association of obesity with recurrence risk is causal is unknown, and the impact of obesity on MRD and breast cancer recurrence has not been reported in humans or in animal models.

METHODS

Doxycycline-inducible primary mammary tumors were generated in intact MMTV-rtTA;TetO-HER2/neu (MTB/TAN) mice or orthotopic recipients fed a high-fat diet (HFD; 60% kcal from fat) or a control low-fat diet (LFD; 10% kcal from fat). Following oncogene downregulation and tumor regression, mice were followed for clinical recurrence. Body weight was measured twice weekly and used to segregate HFD mice into obese (i.e., responders) and lean (i.e., nonresponders) study arms, and obesity was correlated with body fat percentage, glucose tolerance (measured using intraperitoneal glucose tolerance tests), serum biomarkers (measured by enzyme-linked immunosorbent assay), and tissue transcriptomics (assessed by RNA sequencing). MRD was quantified by droplet digital PCR.

RESULTS

HFD-Obese mice weighed significantly more than HFD-Lean and LFD control mice (p < 0.001) and had increased body fat percentage (p < 0.001). Obese mice exhibited fasting hyperglycemia, hyperinsulinemia, and impaired glucose tolerance, as well as decreased serum levels of adiponectin and increased levels of leptin, resistin, and insulin-like growth factor 1. Tumor recurrence was accelerated in HFD-Obese mice compared with HFD-Lean and LFD control mice (median relapse-free survival 53.0 days vs. 87.0 days vs. 80.0 days, log-rank p < 0.001; HFD-Obese compared with HFD-Lean HR 2.52, 95% CI 1.52-4.16; HFD-Obese compared with LFD HR 2.27, 95% CI 1.42-3.63). HFD-Obese mice harbored a significantly greater number of residual tumor cells than HFD-Lean and LFD mice (12,550 ± 991 vs. 7339 ± 2182 vs. 4793 ± 1618 cells, p < 0.001).

CONCLUSION

These studies provide a genetically engineered mouse model for study of the association of diet-induced obesity with breast cancer recurrence. They demonstrate that this model recapitulates physiological changes characteristic of obese patients, establish that the association between obesity and recurrence risk is causal in nature, and suggest that obesity is associated with the increased survival and persistence of residual tumor cells.

Free Fatty Acids Rewire Cancer Metabolism in Obesity-Associated Breast Cancer via Estrogen Receptor and mTOR Signaling

Obesity is a risk factor for postmenopausal estrogen receptor alpha (ERα)-positive (ER⁺) breast cancer. Molecular mechanisms underlying factors from plasma that contribute to this risk and how these mechanisms affect ERα signaling have yet to be elucidated. To identify such mechanisms, we performed whole metabolite and protein profiling in plasma samples from women at high risk for breast cancer, which led us to focus on factors that were differentially present in plasma of obese versus nonobese postmenopausal women. These studies, combined with in vitro assays, identified free fatty acids (FFA) as circulating plasma factors that correlated with increased proliferation and aggressiveness in ER⁺ breast cancer cells. FFAs activated both the ERα and mTOR pathways and rewired metabolism in breast cancer cells. Pathway preferential estrogen-1 (PaPE-1), which targets ERα and mTOR signaling, was able to block changes induced by FFA and was more effective in the presence of FFA. Collectively, these data suggest a role for obesity-associated gene and metabolic rewiring in providing new targetable vulnerabilities for ER⁺ breast cancer in postmenopausal women. Furthermore, they provide a basis for preclinical and clinical trials where the impact of agents that target ERα and mTOR signaling cross-talk would be tested to prevent ER⁺ breast cancers in obese postmenopausal women. SIGNIFICANCE: These findings show that obesity-associated changes in certain blood metabolites rewire metabolic programs in cancer cells, influence mammary epithelial cell tumorigenicity and aggressiveness, and increase breast cancer risk.

Body Mass Index at Diagnosis as a Prognostic Factor for Early-Stage Invasive Breast Cancer after Surgical Resection

BACKGROUND

The aim of this study was to investigate the association between body mass index (BMI) and prognosis of Chinese women with breast cancer.

PATIENTS AND METHODS

3,380 primary breast cancer patients who underwent surgery from 2010 to 2012 were selected and classified as low BMI group (BMI < 25.0) and high BMI group (BMI ≥ 25.0). The follow-up data for disease-free survival (DFS) and overall survival (OS) were obtained from 3,178 patients (median follow-up of 58 months). Cox regression analysis was used to evaluate the effect of BMI on DFS and OS.

RESULTS

The high BMI group showed more aggressive pathological features. BMI was negatively associated with OS (hazard ratio (HR) 1.33, 95% confidence interval (CI) 1.06-1.66; p = 0.012) but not DFS (HR 1.15, 95% CI 0.94-1.40; p = 0.17). Furthermore, when stratified by age, BMI was significantly and negatively associated with OS (HR 1.43, 95% CI 1.05-1.95; p = 0.025) in patients above 50 years of age, but this effect was not detected in younger patients.

CONCLUSION

BMI was an independent prognostic factor of OS in Chinese women with breast cancer, and age might be a mitigating factor. Among patients above 50 years of age, those with a high BMI were at greater risk of poor prognosis compared to individuals with a low BMI.

Estrogen stimulates female cancer progression by inducing myeloid-derived suppressive cells: investigations on pregnant and non-pregnant experimental models

Objective

To investigate the clinical implications of 17β-estradiol (E2) in estrogen receptor α (ERα)-negative female cancer progression as well as the underlying biological mechanisms.

Methods

Clinical data from 306 locally-advanced cervical cancer (stage IIB-IVA) patients were analyzed in order to investigate the relationships between age, serum E2 levels, and treatment outcomes. Clinical samples, ERα-negative cervical and breast cancer cell lines, and mouse xenograft models of cervical and breast cancers were employed in order to elucidate the mechanisms responsible for the E2- and pregnancy-mediated progression of cervical and breast cancers, with a focus on the role of myeloid-derived suppressor cells (MDSC).

Results

Younger patients with elevated E2 levels showed significantly shorter progression-free survival (P = 0.040) and overall survival (P = 0.039). The exogenous E2 treatment stimulated the mobilization of MDSC from bone marrow and directly augmented their suppressive activities, leading to the progression of ERα-negative cervical and breast cancers. The co-administration of an anti-Gr-1 neutralizing antibody with E2 prevented the E2-mediated induction of MDSC, and attenuated E2-mediated tumor growth in cervical and breast cancer xenografts. Significantly increased MDSC numbers and enhanced tumor growth were observed during pregnancy in mice with cervical or breast cancer. Significantly increased MDSC numbers were also observed during pregnancy in cervical cancer patients.

Conclusions

E2 facilitates the progression of ERα-negative cervical or breast cancer under non-pregnant and pregnant conditions by inducing MDSC. MDSC inhibition therapy may have therapeutic efficacy in premenopausal or pregnant female cancer patients.

Impact of body mass index on tumor recurrence among patients undergoing curative-intent resection of intrahepatic cholangiocarcinoma- a multi-institutional international analysis

BACKGROUND

The association between body mass index (BMI) and long-term outcomes of patients with ICC has not been well defined. We sought to define the presentation and oncologic outcomes of patients with ICC undergoing curative-intent resection, according to their BMI category.

METHODS

Patients who underwent resection of ICC were identified in a multi-institutional database. Patients were categorized as normal weight (BMI 18.5-24.9 kg/m²), overweight (BMI 25.0-29.9 kg/m²) and obese (BMI≥30 kg/m²) according to the World Health Organization (WHO) definition. Impact of clinico-pathological factors on recurrence-free survival (RFS) was assessed using Cox proportional hazards model among patients in the three BMI categories.

RESULTS

Among a total of 790 patients undergoing curative-intent resection of ICC in the analytic cohort, 399 (50.5%) had normal weight, 274 (34.7%) were overweight and 117 (14.8%) were obese. Caucasian patients were more likely to be obese (66.7%, n = 78) and overweight (47.1%, n = 129) compared with Asian (obese: 18.8%, n = 22; overweight: 46%, n = 126) and other races (obese: 14.5%, n = 17; overweight: 6.9%, n = 19)(p < 0.001). There were no differences in the presence of cirrhosis (10.9%, vs. 12.8%, vs. 12.9%), preoperative jaundice (8.6% vs. 9.5% vs. 12.0%), or levels of CA 19-9 (75, IQR 24.6-280 vs. 50.9, IQR 17.9-232 vs. 43, IQR 16.9-192.7) among the BMI groups (all p > 0.05). On multivariable analysis, increased BMI was an independent risk factor for tumor recurrence (OR 1.16, 95% CI 1.02-1.32, for every 5 unit increase).

CONCLUSION

Increasing BMI was associated with incremental increases in the risk of recurrence following curative-intent resection of ICC. Future studies should aim to achieve a better understanding of BMI-related factors relative to prognosis of patients with ICC.

Influence of Body Mass Index on the Clinicopathologic Features of Papillary Thyroid Carcinoma

BACKGROUND

Epidemiologic studies have demonstrated an increased risk for papillary thyroid carcinoma (PTC) with increasing body mass index (BMI). However, the relationships between excess weight and the behavior of PTC are inconsistent. The aim of this study was to evaluate the impact of excess weight on clinicopathologic features of PTC and on patient outcomes.

METHODS

Data from 417 patients with PTC who underwent total thyroidectomy with cervical lymph node dissection were retrospectively analyzed. On the basis of World Health Organization standardized categories of BMI, patients were divided into 4 groups: underweight, normal weight, overweight, and obese. Histopathologic tumor features, stage at diagnosis, and disease status were determined by chart review. Logistic regression models were used to define associations between BMI and clinicopathologic features of PTC. Cox proportional-hazards models were used to assess associations between BMI and locoregional recurrence.

RESULTS

Overweight (odds ratio [OR], 3.90; P = .040) and obesity (OR, 9.19; P = .012) were independent predictors of vascular invasion. Furthermore, obesity (OR, 6.14; P = .004) was an independent predictor of extrathyroidal invasion. During follow-up (median, 29 months; range, 5-87 months), 48 patients (11.5%) experienced locoregional recurrence. There were no significant differences in locoregional recurrence of PTC among BMI groups. When adjusted for other confounding factors, extrathyroidal invasion (OR, 8.35; P < .001), vascular invasion (OR, 3.57; P < .001), cervical lymph node metastasis (OR, 3.71; P = .009), and advanced tumor-node-metastasis stage (OR, 3.81; P < .001) were identified as independent factors for locoregional recurrence.

CONCLUSIONS

Higher BMI was associated with extrathyroidal invasion and vascular invasion in patients with PTC, which suggests that excess weight is associated with aggressive clinicopathologic features of PTC. But patients with higher BMI did not have an increased risk for developing postoperative complications and locoregional recurrence.

Obesity as an independent predictive factor for pathologic complete response after neoadjuvant chemoradiation in rectal cancer

PURPOSE

The predictive role of obesity on pathologic complete response (pCR) after neoadjuvant chemoradiation (nCRT) in rectal cancer remains controversial. This study aimed to evaluate the association between obesity and pathologic response in patients with rectal cancer following nCRT.

METHODS

A total of 320 patients with primary rectal cancer who underwent curative resection after nCRT between January 2010 and September 2014 were enrolled in this study. Obesity was defined as body mass index of ≥25 kg/m2. Clinicopathologic characteristics were analyzed to identify independent predictive factors for pCR.

RESULTS

Among the included patients, 23.4% (n = 75) were obese, and 14.7% (n = 47) showed pCR. Baseline characteristics were generally similar between obese and nonobese patients, except that women (P = 0.001) and cT2 tumors (P = 0.001) were more common in the obese group. Multivariate logistic regression analysis revealed that obesity (odds ratio [OR] = 2.051; 95% confidence interval [CI], 1.009-4.168), cT2 (OR, 3.614; 95% CI, 1.166-11.202), and pretreatment carcinoembryonic antigen <5 ng/mL (OR, 2.921; 95% CI, 1.365-6.253) were independent predictors for pCR. Obesity was not associated with disease-free survival or local recurrence-free survival.

CONCLUSION

Obesity was an independent predictive factor for pCR following nCRT in rectal cancer, but was not associated with recurrence. Further studies are needed to clarify the association between obesity and prognosis of rectal cancer after nCRT.

Updating the role of obesity and cholesterol in breast cancer

BACKGROUND

Breast cancer is the second most common cause of cancer-related death among women. Advances in our understanding of the disease have translated into better diagnostics and more effective therapeutics, leading to earlier detection and improved outcomes. Several studies have pointed at lifestyle and environmental factors as contributory for the onset and progression of the disease. Obesity and cholesterol stand out for their potential causal relationship with breast cancer and ease of modification.

MAIN TEXT

Obesity and cholesterol represent risk factors for breast cancer, but their impact is largely affected by cofounding variables including menopausal status, disease subtype, and inflammation. Establishing a causal relationship between lifestyle factors and clinical outcomes may be challenging. Epidemiological studies and meta-analyses have rendered conflicting or sometimes contradictory results, possibly owing to the multifactorial nature of the disease. We discuss the supporting evidence and limitations in our understanding of obesity and cholesterol as risk factors for breast cancer.

CONCLUSIONS

There is sufficient evidence that obesity and cholesterol impact clinical outcomes. Physicians are advised to take steps to help patients with their weight, such as recommending dietary and lifestyle interventions.

Statin use and breast cancer survival - a Swedish nationwide study

BACKGROUND

A sizeable body of evidence suggests that statins can cease breast cancer progression and prevent breast cancer recurrence. The latest studies have, however, not been supportive of such clinically beneficial effects. These discrepancies may be explained by insufficient power. This considerably sized study investigates the association between both pre- and post-diagnostic statin use and breast cancer outcome.

METHODS

A Swedish nation-wide retrospective cohort study of 20,559 Swedish women diagnosed with breast cancer (July 1st, 2005 through 2008). Dispensed statin medication was identified through the Swedish Prescription Registry. Breast cancer related death information was obtained from the national cause-of-death registry until December 31st, 2012. Cox regression models yielded hazard ratios (HR) and 95% confidence intervals (CI) regarding associations between statin use and breast cancer-specific and overall mortality.

RESULTS

During a median follow-up time of 61.6 months, a total of 4678 patients died, of which 2669 were considered breast cancer related deaths. Compared to non- or irregular use, regular pre-diagnostic statin use was associated with lower risk of breast cancer related deaths (HR = 0.77; 95% CI 0.63-0.95, P = 0.014). Similarly, post-diagnostic statin use compared to non-use was associated with lower risk of breast cancer related deaths (HR = 0.83; 95% CI 0.75-0.93, P = 0.001).

CONCLUSION

This study supports the notion that statin use is protective regarding breast cancer related mortality in agreement with previous Scandinavian studies, although less so with studies in other populations. These disparities should be further investigated to pave the way for future randomized clinical trials investigating the role of statins in breast cancer.

[Breast cancer, obesity and adipose tissue: a high-risk combination]

Obesity increases the occurrence of post-menopausal breast cancer and negatively affects prognosis independently of menopausal status. After summarizing the available epidemiological data concerning these associations, we will show that a deleterious crosstalk is established during tumor progression between cancer cells and the surrounding mammary adipose tissue (MAT). In obesity, the chronic sub-inflammatory state of MAT could amplify the negative effect of this crosstalk although other mechanisms also warrant further study. Finally, we will discuss the efficiency of weight loss in both primary prevention and recurrence, a strategy that could be more complex that initially thought.

Impact of Obesity on Clinicopathologic Characteristics and Disease Prognosis in Pre- and Postmenopausal Breast Cancer Patients: A Retrospective Institutional Study

PURPOSE

To investigate the association between obesity and breast cancer clinicopathologic characteristics at presentation along with prognostic impact among Jordanian breast cancer patients. Such data are lacking in Arabian countries.

METHODS

In this retrospective study, 348 breast cancer patients were included. Analyses were conducted for associations between body mass index (BMI) and age at diagnosis, tumor clinicopathologic characteristics, and molecular subtypes. Eight prognostic factors were considered, and total prognostic scores were calculated. The analysis was stratified by menopausal status. Multivariate logistic stepwise regression analysis was conducted to identify predictors for breast cancer recurrence and death.

RESULTS

Mean age at diagnosis was 50.98 ± 10.96 years. Mean BMI at diagnosis was 29.52 ± 5.32 kg/m². Mean age at diagnosis was significantly higher for overweight and obese patients compared to underweight/normal patients (P < 0.001). A significant positive correlation was observed between patient age and BMI at diagnosis (r = 0.251, P < 0.001). Grade of carcinoma was significantly correlated with BMI in the whole population examined (P=0.003). Obese breast cancer patients had significantly higher prognostic scores compared to nonobese cases, indicating worse prognostic features at presentation (P=0.034). Stratification of data analysis based on menopausal status revealed significant associations between obesity and each of tumor stage and grade among postmenopausal but not premenopausal patients (P=0.019 and P=0.031, respectively). Similarly, postmenopausal obese patients had significantly higher prognostic scores compared to nonobese counterparts (P=0.007), indicating worse prognosis, a finding which was also absent among premenopausal breast cancer patients. No significant association between BMI with expression status of hormone receptors, HER2, lymphovascular invasion, and molecular subtypes was found among patients. BMI was a significant predictor for disease recurrence in which obese breast cancer patients had greater odds (2-fold) to develop locoregional and distant recurrence compared to nonobese cases (P=0.011).

CONCLUSIONS

Obesity was associated with advanced stage and grade of breast carcinoma at diagnosis. The impact of BMI on clinicopathologic characteristics and prognosis was confined to postmenopausal cases. Jordanian obese breast cancer patients are at greater risk of breast cancer recurrence and reduced survival compared to their nonobese counterparts.

Fatty acids: Adiposity and breast cancer chemotherapy, a bad synergy?

Globally, breast cancer continues to be a major concern in women's health. Lifestyle related risk factors, specifically excess adipose tissue (adiposity) has reached epidemic proportions and has been identified as a major risk factor in the development of breast cancer. Dysfunctional adipose tissue has evoked research focusing on its association with metabolic-related conditions, breast cancer risk and progression. Adipose dysfunction in coordination with immune cells and inflammation, are responsible for accelerated cell growth and survival of cancer cells. Recently, evidence also implicates adiposity as a potential risk factor for chemotherapy resistance. Chemotherapeutic agents have been shown to negatively impact adipose tissue. Since adipose tissue is a major storage site for fatty acids, it is not unlikely that these negative effects may disrupt adipose tissue homeostasis. It is therefore argued that fatty acid composition may be altered due to the chemotherapeutic pharmacokinetics, which in turn could have severe health related outcomes. The underlying molecular mechanisms elucidating the effects of fatty acid composition in adiposity-linked drug resistance are still unclear and under explored. This review focuses on the potential role of adiposity in breast cancer and specifically emphasizes the role of fatty acids in cancer progression and treatment resistance.

Prostaglandin E2 down-regulates sirtuin 1 (SIRT1), leading to elevated levels of aromatase, providing insights into the obesity-breast cancer connection

Obesity increases the risk of hormone receptor-positive breast cancer in postmenopausal women. Levels of aromatase, the rate-limiting enzyme in estrogen biosynthesis, are increased in the breast tissue of obese women. Both prostaglandin E₂ (PGE₂) and hypoxia-inducible factor 1α (HIF-1α) contribute to the induction of aromatase in adipose stromal cells (ASCs). Sirtuin 1 (SIRT1) binds, deacetylates, and thereby inactivates HIF-1α. Here, we sought to determine whether SIRT1 also plays a role in regulating aromatase expression. We demonstrate that reduced SIRT1 levels are associated with elevated levels of acetyl-HIF-1α, HIF-1α, and aromatase in breast tissue of obese compared with lean women. To determine whether these changes were functionally linked, ASCs were utilized. In ASCs, treatment with PGE₂, which is increased in obese individuals, down-regulated SIRT1 levels, leading to elevated acetyl-HIF-1α and HIF-1α levels and enhanced aromatase gene transcription. Chemical SIRT1 activators (SIRT1720 and resveratrol) suppressed the PGE₂-mediated induction of acetyl-HIF-1α, HIF-1α, and aromatase. Silencing of p300/CBP-associated factor (PCAF), which acetylates HIF-1α, blocked PGE₂-mediated increases in acetyl-HIF-1α, HIF-1α, and aromatase. SIRT1 overexpression or PCAF silencing inhibited the interaction between HIF-1α and p300, a coactivator of aromatase expression, and suppressed p300 binding to the aromatase promoter. PGE₂ acted via prostaglandin E2 receptor 2 (EP₂) and EP₄ to induce activating transcription factor 3 (ATF3), a repressive transcription factor, which bound to a CREB site within the SIRT1 promoter and reduced SIRT1 levels. These findings suggest that reduced SIRT1-mediated deacetylation of HIF-1α contributes to the elevated levels of aromatase in breast tissues of obese women.

Molecular mechanisms linking high body mass index to breast cancer etiology in post-menopausal breast tumor and tumor-adjacent tissues

PURPOSE

In post-menopausal women, high body mass index (BMI) is an established breast cancer risk factor and is associated with worse breast cancer prognosis. We assessed the associations between BMI and gene expression of both breast tumor and adjacent tissue in estrogen receptor-positive (ER+) and estrogen receptor-negative (ER-) diseases to help elucidate the mechanisms linking obesity with breast cancer biology in 519 post-menopausal women from the Nurses' Health Study (NHS) and NHSII.

METHODS

Differential gene expression was analyzed separately in ER+ and ER- disease both comparing overweight (BMI ≥ 25 to < 30) or obese (BMI ≥ 30) women to women with normal BMI (BMI < 25), and per 5 kg/m² increase in BMI. Analyses controlled for age and year of diagnosis, physical activity, alcohol consumption, and hormone therapy use. Gene set enrichment analyses were performed and validated among a subset of post-menopausal cases in The Cancer Genome Atlas (for tumor) and Polish Breast Cancer Study (for tumor-adjacent).

RESULTS

No gene was differentially expressed by BMI (FDR < 0.05). BMI was significantly associated with increased cellular proliferation pathways, particularly in ER+ tumors, and increased inflammation pathways in ER- tumor and ER- tumor-adjacent tissues (FDR < 0.05). High BMI was associated with upregulation of genes involved in epithelial-mesenchymal transition in ER+ tumor-adjacent tissues.

CONCLUSIONS

This study provides insights into molecular mechanisms of BMI influencing post-menopausal breast cancer biology. Tumor and tumor-adjacent tissues provide independent information about potential mechanisms.

Longer Times of Receipt of Adjuvant Endocrine Therapy Correspond to Improved Functional Capacity and Lower Adiposity in Women Receiving Adjuvant Therapy

PURPOSE

To study the use of functional capacity (FC) level and duration of aromatase inhibitor (AI) therapy with adiposity parameters in women with breast cancer.

PATIENTS AND METHODS

FC was evaluated through the Health Assessment Questionnaire, which was assessed by classification and divided into 3 groups: G1 = mild to moderate difficulty, G2 = moderate to severe disability, and G3 = severe or very severe disability. Body mass, height, and waist circumference (WC) were measured, and body mass index (BMI) was calculated. Bioelectrical impedance analysis was used to calculate body fat (BF) and fat-free mass. The women were divided into 2 time groups (T1 and T2), which were determined by the median months of AI use (T1 ≤ 29.5 and T2 > 29.5 months).

RESULTS

Impaired FC and adiposity parameters were significantly positively correlated. In addition, physical exercise was significantly lower in women assessed as G2 and G3 compared to those assessed as G1. The effect of FC on BMI, BF, and WC was also verified, as was the effect of the duration of AI receipt on BMI and BF. Women at T1 had significantly greater functional disability, BMI, and BF values. In addition, although not statistically significant, women in T1 who were assessed as G3 presented higher BMI, WC, and BF values than those in T2.

CONCLUSION

Adiposity above the recommended parameters and impaired FC were associated with the shortest time of receipt of adjuvant endocrine therapy with AI.

Breast Cancer Tissue Markers, Genomic Profiling, and Other Prognostic Factors: A Primer for Radiologists

An understanding of prognostic factors in breast cancer is imperative for guiding patient care. Increased tumor size and more advanced nodal status are established independent prognostic factors of poor outcomes and are incorporated into the American Joint Committee on Cancer (AJCC) TNM (primary tumor, regional lymph node, distant metastasis) staging system. However, other factors including imaging findings, histologic evaluation results, and molecular findings can have a direct effect on a patient's prognosis, including risk of recurrence and relative survival. Several microarray panels for gene profiling of tumors are approved by the U.S. Food and Drug Administration and endorsed by the American Society of Clinical Oncology. This article highlights prognostic factors currently in use for individualizing and guiding breast cancer therapy and is divided into four sections. The first section addresses patient considerations, in which modifiable and nonmodifiable prognostic factors including age, race and ethnicity, and lifestyle factors are discussed. The second part is focused on imaging considerations such as multicentric and/or multifocal disease, an extensive intraductal component, and skin or chest wall involvement and their effect on treatment and prognosis. The third section is about histopathologic findings such as the grade and presence of lymphovascular invasion. Last, tumor biomarkers and tumor biology are discussed, namely hormone receptors, proliferative markers, and categorization of tumors into four recognized molecular subtypes including luminal A, luminal B, human epidermal growth factor receptor 2-enriched, and triple-negative tumors. By understanding the clinical effect of these prognostic factors, radiologists, along with a multidisciplinary team, can use these tools to achieve individualized patient care and to improve patient outcomes. ^©RSNA, 2018.

Obesity-Activated Adipose-Derived Stromal Cells Promote Breast Cancer Growth and Invasion

Obese women diagnosed with breast cancer have an increased risk for metastasis, and the underlying mechanisms are not well established. Within the mammary gland, adipose-derived stromal cells (ASCs) are heterogeneous cells with the capacity to differentiate into multiple mesenchymal lineages. To study the effects of obesity on ASCs, mice were fed a control diet (CD) or high-fat diet (HFD) to induce obesity, and ASCs were isolated from the mammary glands of lean and obese mice. We observed that obesity increased ASCs proliferation, decreased differentiation potential, and upregulated expression of α-smooth muscle actin, a marker of activated fibroblasts, compared to ASCs from lean mice. To determine how ASCs from obese mice impacted tumor growth, we mixed ASCs isolated from CD- or HFD-fed mice with mammary tumor cells and injected them into the mammary glands of lean mice. Tumor cells mixed with ASCs from obese mice grew significantly larger tumors and had increased invasion into surrounding adipose tissue than tumor cells mixed with control ASCs. ASCs from obese mice demonstrated enhanced tumor cell invasion in culture, a phenotype associated with increased expression of insulin-like growth factor-1 (IGF-1) and abrogated by IGF-1 neutralizing antibodies. Weight loss induced in obese mice significantly decreased expression of IGF-1 from ASCs and reduced the ability of the ASCs to induce an invasive phenotype. Together, these results suggest that obesity enhances local invasion of breast cancer cells through increased expression of IGF-1 by mammary ASCs, and weight loss may reverse this tumor-promoting phenotype.

Statins: a role in breast cancer therapy?

Statin drugs have been used for more than two decades to treat hypercholesterolemia and as cardio-preventive drugs, resulting in a marked decrease in cardiovascular morbidity and mortality worldwide. Statins halt hepatic cholesterol biosynthesis by inhibiting the rate-limiting enzyme in the mevalonate pathway, hydroxymethylglutaryl-coenzyme A reductase (HMGCR). The mevalonate pathway regulates a host of biochemical processes in addition to cholesterol production. Attenuation of these pathways is likely responsible for the myriad benefits of statin therapy beyond cholesterol reduction - the so-called pleiotropic effects of statins. Chief amongst these purported effects is anti-cancer activity. A considerable body of preclinical, epidemiologic and clinical evidence shows that statins impair proliferation of breast cancer cells and reduce the risk of breast cancer recurrence. Potential mechanisms for this effect have been explored in laboratory models, but remain poorly understood and require further investigation. The number of clinical trials assessing the putative clinical benefit of statins in breast cancer is increasing. Currently, a total of 30 breast cancer/statin trials are listed at the global trial identifier website clinicaltrials.gov. Given the compelling evidence from performed trials in a variety of clinical settings, there have been calls for a clinical trial of statins in the adjuvant breast cancer setting. It would be imperative for such a trial to incorporate tumour biomarkers predictive of statin response in its design and analysis plan. Ongoing translational clinical trials aimed at biomarker discovery will help identify, which breast cancer patients are most likely to benefit from adjuvant statin therapy, and will add valuable clinical knowledge to the field.

Obesity promotes the expansion of metastasis-initiating cells in breast cancer

Background

Obesity is a strong predictor of poor prognosis in breast cancer, especially in postmenopausal women. In particular, tumors in obese patients tend to seed more distant metastases, although the biology behind this observation remains poorly understood.

Methods

To elucidate the effects of the obese microenvironment on metastatic spread, we ovariectomized C57BL/6 J female mice and fed them either a regular diet (RD) or a high-fat diet (HFD) to generate a postmenopausal diet-induced obesity model. We then studied tumor progression to metastasis of Py230 and EO771 grafts. We analyzed and phenotyped the RD and HFD tumors and the surrounding adipose tissue by flow cytometry, qPCR, immunohistochemistry (IHC) and western blot. The influence of the microenvironment on tumor cells was assessed by performing cross-transplantation of RD and HFD tumor cells into other RD and HFD mice. The results were analyzed using the unpaired Student t test when comparing two variables, otherwise we used one-way or two-way analysis of variance. The relationship between two variables was calculated using correlation coefficients.

Results

Our results show that tumors in obese mice grow faster, are also less vascularized, more hypoxic, of higher grade and enriched in CD11b⁺Ly6G⁺ neutrophils. Collectively, this favors induction of the epithelial-to-mesenchymal transition and progression to claudin-low breast cancer, a subtype of triple-negative breast cancer that is enriched in cancer stem cells. Interestingly, transplanting HFD-derived tumor cells in RD mice transfers enhanced tumor growth and lung metastasis formation.

Conclusions

These data indicate that a pro-metastatic effect of obesity is acquired by the tumor cells in the primary tumor independently of the microenvironment of the secondary site.

Graphical abstract

Effects of postmenopausal obesity on primary breast cancer tumoursᅟ

Electronic supplementary material

The online version of this article (10.1186/s13058-018-1029-4) contains supplementary material, which is available to authorized users.

Obesity and mortality after locoregional breast cancer diagnosis

PURPOSE

Higher mortality after a breast cancer diagnosis has been observed among women who are obese. We investigated the relationships between body mass index (BMI) and all-cause or breast cancer-specific mortality after a diagnosis of locoregional breast cancer.

METHODS

Women diagnosed in 2004 with AJCC Stage I, II, or III breast cancer (n = 5394) were identified from a population-based National Program of Cancer Registries (NPCR) patterns of care study (POC-BP) drawing from registries in seven U.S. states. Differences in overall and breast cancer-specific mortality were investigated using Cox proportional hazards regression models adjusting for demographic and clinical covariates, including age- and stage-based subgroup analyses.

RESULTS

In women 70 or older, higher BMI was associated with lower overall mortality (HR for a 5 kg/m² difference in BMI = 0.85, 95% CI 0.75-0.95). There was no significant association between BMI and overall mortality for women under 70. BMI was not associated with breast cancer death in the full sample, but among women with Stage I disease; those in the highest BMI category had significantly higher breast cancer mortality (HR for BMI ≥ 35 kg/m² vs. 18.5-24.9 kg/m² = 4.74, 95% CI 1.78-12.59).

CONCLUSIONS

Contrary to our hypothesis, greater BMI was not associated with higher overall mortality. Among older women, BMI was inversely related to overall mortality, with a null association among younger women. Higher BMI was associated with breast cancer mortality among women with Stage I disease, but not among women with more advanced disease.

Lifestyle Medicine: A Brief Review of Its Dramatic Impact on Health and Survival

By ignoring the root causes of disease and neglecting to prioritize lifestyle measures for prevention, the medical community is placing people at harm. Advanced nations, influenced by a Western lifestyle, are in the midst of a health crisis, resulting largely from poor lifestyle choices. Epidemiologic, ecologic, and interventional studies have repeatedly indicated that most chronic illnesses, including cardiovascular disease, cancer, and type 2 diabetes, are the result of lifestyles fueled by poor nutrition and physical inactivity.In this article, we describe the practice of lifestyle medicine and its powerful effect on these modern instigators of premature disability and death. We address the economic benefits of prevention-based lifestyle medicine and its effect on our health care system: A system on the verge of bankruptcy. We recommend vital changes to a disastrous course. Many deaths and many causes of pain, suffering, and disability could be circumvented if the medical community could effectively implement and share the power of healthy lifestyle choices. We believe that lifestyle medicine should become the primary approach to the management of chronic conditions and, more importantly, their prevention. For future generations, for our own health, and for the Hippocratic Oath we swore to uphold ("First do no harm"), the medical community must take action. It is our hope that the information presented will inspire our colleagues to pursue lifestyle medicine research and incorporate such practices into their daily care of patients. The time to make this change is now.

Serum adiponectin in breast cancer: A meta-analysis

BACKGROUND

Accumulating data have found that adiponectin is involved in development of breast cancer (BC). However, these results were inconsistent.

METHOD

A systematic search in PubMed, Embase, ISI Web of Science, and Chinese National Knowledge Infrastructure databases were conducted up to October 1, 2017. The standardized mean difference (SMD) with 95% confidence interval was applied to pool the effect size.

RESULTS

Finally, 31 eligible studies were included in this meta-analysis. The overall results indicated that serum adiponectin levels in BC cases were significantly lower than the controls (SMD = -0.33, P < 0.0001). As for the subgroup analysis of menstrual status, serum adiponectin levels were significantly lower in pre- and postmenopausal BC cases. Moreover, the subgroup analysis by ethnicity in pre- and postmenopausal group indicated an inverse association between adiponectin levels and BC risk in Asian population, but not in Caucasian population.

CONCLUSION

The present meta-analysis suggests that low serum adiponectin concentration may be associated with an increased BC risk in premenopausal and postmenopausal women, especially among Asians. Adiponectin may serve as a biomarker of BC risk and help to identify subjects at high risk for BC development.

Complications of obesity

Global obesity rates have increased exponentially in recent decades. People are becoming obese younger, morbid obesity is increasing and the full health implications are only beginning to be seen. This article discusses the latest epidemiological data on obesity in adults and children, and systemically reviews the complications associated with the condition.

Adipocytes induce distinct gene expression profiles in mammary tumor cells and enhance inflammatory signaling in invasive breast cancer cells

Obesity is a known risk factor for breast cancer. Since obesity rates are constantly rising worldwide, understanding the molecular details of the interaction between adipose tissue and breast tumors becomes an urgent task. To investigate potential molecular changes in breast cancer cells induced by co-existing adipocytes, we used a co-culture system of different breast cancer cell lines (MCF-7 and T47D: ER+/PR+/HER2- and MDA-MB-231: ER-/PR-/HER2-) and murine 3T3-L1 adipocytes. Here, we report that co-culture with adipocytes revealed distinct changes in global gene expression pattern in the different breast cancer cell lines. Our microarray data revealed that in both ER+ cell lines, top upregulated genes showed significant enrichment for hormone receptor target genes. In triple-negative MDA-MB-231 cells, co-culture with adipocytes led to the induction of pro-inflammatory genes, mainly involving genes of the Nf-κB signaling pathway. Moreover, co-cultured MDA-MB-231 cells showed increased secretion of the pro-inflammatory interleukins IL-6 and IL-8. Using a specific NF-κB inhibitor, these effects were significantly decreased. Finally, migratory capacities were significantly increased in triple-negative breast cancer cells upon co-culture with adipocytes, indicating an enhanced aggressive cell phenotype. Together, our studies illustrate that factors secreted by adipocytes have a significant impact on the molecular biology of breast cancer cells.

Early breast cancer: why does obesity affect prognosis?

High BMI is associated with an increased risk of breast cancer in post-menopausal women but poorer outcomes in all age groups. The underlying mechanism is likely to be multi-factorial. Patients with a high BMI may present later due to body habitus. Some studies have also indicated an increased incidence of biologically adverse features, including a higher frequency of oestrogen receptor (ER negative) tumours, in obese patients. Obese patients have a higher frequency of surgical complications, potentially delaying systemic therapies, and reports suggest that chemotherapy and endocrine therapy are less effective in patients with BMI ≥30 kg/m2.High BMI is generally interpreted as excess adiposity and a World Cancer Research Fund report judged that the associations between BMI and incidence of breast cancer were due to body fatness. However, BMI cannot distinguish lean mass from fat mass, or characterise body fat distribution. Most chemotherapy drugs are dosed according to calculated body surface area (BSA). Patients with a similar BSA or BMI may have wide variations in their distribution of adipose tissue and skeletal muscle (body composition); however, few studies have looked at the effect of this on chemotherapy tolerance or effectiveness. Finally, adjuvant treatments for breast cancer can themselves result in body composition changes.Research is required to fully understand the biological mechanisms by which obesity influences cancer behaviour and the impact of obesity on treatment effectiveness and tolerance so that specific management strategies can be developed to improve the prognosis of this patient group.

Body mass index and prognosis of breast cancer: An analysis by menstruation status when breast cancer diagnosis

OBJECTIVE

To examine whether obesity/overweight is a risk predictor for breast cancer recurrence and death by menopausal status in a retrospective study.

METHODS

We performed a retrospective analysis of 1017 breast cancer patients treated in our hospital from January 2004 to December 2012. Three groups were divided according to body mass index (BMI) when breast cancer diagnosis: normal weight, BMI < 25.0 kg/m; overweight, 25.0≤BMI < 30.0 kg/m; and obesity, BMI≥30.0 kg/m. The clinicopathological characteristics and clinical outcomes of patients within 5 years following breast cancer diagnosed were analyzed. Subgroup analyses of BMI on breast cancer prognosis were analyzed according to the menopausal status when breast cancer diagnosis. The Cox proportional hazards model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Overweight and obesity groups were associated with larger size tumors, older age, increased proportion of postmenopausal patients and less patients choosing anthracycline and/or taxane regimen. The 5-year disease-free survival (DFS) and overall survival (OS) decreased in overweight and obese patients (P < .001), and both overweight and obesity were independent predictors for increased risks of breast cancer relapse and death (P < .001). When stratified by menopausal status, both overweight and obesity were associated with reduced 5-year DFS and OS in postmenopausal patients (P < .050), and multivariate analysis showed that the risk of relapse and breast cancer mortality in these 2 groups also increased (P < .050). Among premenopausal patients, the risks of relapse and death were significantly increased in obesity group rather than overweight group by multivariate analysis.

CONCLUSION

Overweight and obesity might be independently associated with poorer prognosis for breast cancer patients, and the effects of overweight on the breast cancer prognosis seem to be related to menopausal status.

Increasing preoperative body size in breast cancer patients between 2002 and 2016: implications for prognosis

Overweight and obesity are increasing worldwide, but the extent in breast cancer patients is unknown. The two aims were to study secular trends in preoperative body mass index (BMI), waist circumference, and breast volume and their impacts on clinical outcome. BMI, waist circumference, and breast volume were measured preoperatively in 24–99-year-old primary breast cancer patients (n = 640) in Sweden 2002–2016. The measurements were analyzed alone and combined in relation to recurrence and overall survival (OS). BMI, waist circumference, and breast volume increased 2002–2016 (p_trends < 0.0001). Of these, a breast volume ≥ 850 mL was associated with the strongest recurrence-risk (adjusted hazard ratio [_adjHR] 1.67; 95% CI 1.17–2.39), especially combined with waist circumference ≥ 80 cm (_adjHR 2.07; 95% CI 1.25–3.44), while BMI ≥ 25 kg/m² or large waist circumference conferred almost a twofold risk for death (both Log-Rank p ≤ 0.0001). Chemotherapy seemed to counteract the negative impact of a high BMI or large waist circumference on OS. Large breast volume was the strongest predictor for recurrence in all treatment groups. In conclusion, preoperative BMI, waist circumference, and breast volume increased between 2002 and 2016. Larger body size negatively impacted breast cancer-free interval and OS. If confirmed, body measurements may help select patients requiring more individualized treatment.

The significance of cholesterol and its metabolite, 27-hydroxycholesterol in breast cancer

Although significant advances in the treatment of breast cancer have been made, in particular in the use of endocrine therapy, de novo and aquired resistance to therapy, and metastatic recurrence continue to be major clinical problems. Given the high prevalence of breast cancer, new life-style or chemotherapeutic approaches are required. In this regard, cholesterol has emerged as a risk factor for the onset of breast cancer, and elevated cholesterol is associated with a poor prognosis. While treatment with cholesterol lowering medication is not associated with breast cancer risk, it does appear to be protective against recurrence. Importantly, the cholesterol axis represents a potential target for both life-style and pharmacological intervention. This review will outline the clinical and preclinical data supporting a role for cholesterol in breast cancer pathophysiology. Specific focus is given to 27-hydroxycholesterol (27-OHC; (3β,25R)-Cholest-5-ene-3,26-diol)), a primary metabolite of cholesterol that has recently been defined as an endogenous Selective Estrogen Receptor Modulator. Future perspectives and directions are discussed.

Long-term prognostic implications of risk factors associated with tumor size: a case study of women regularly attending screening

Background

Breast cancer prognosis is strongly associated with tumor size at diagnosis. We aimed to identify factors associated with diagnosis of large (> 2 cm) compared to small tumors, and to examine implications for long-term prognosis.

Methods

We examined 2012 women with invasive breast cancer, of whom 1466 had screen-detected and 546 interval cancers that were incident between 2001 and 2008 in a population-based screening cohort, and followed them to 31 December 2015. Body mass index (BMI) was ascertained after diagnosis at the time of study enrollment during 2009. PD was measured based on the contralateral mammogram within 3 years before diagnosis. We used multiple logistic regression modeling to examine the association between tumor size and body mass index (BMI), mammographic percent density (PD), or hormonal and genetic risk factors. Associations between the identified risk factors and, in turn, the outcomes of local recurrence, distant metastases, and death (153 events in total) in women with breast cancer were examined using Cox regression. Analyses were carried out according to mode of detection.

Results

BMI and PD were the only factors associated with tumor size at diagnosis. For BMI (≥25 vs. < 25 kg/m²), the multiple adjusted odds ratios (OR) were 1.37 (95% CI 1.02–1.83) and 2.12 (95% CI 1.41–3.18), for screen-detected and interval cancers, respectively. For PD (≥20 vs. < 20%), the corresponding ORs were 1.72 (95% CI 1.29–2.30) and 0.60 (95% CI 0.40–0.90). Among women with interval cancers, those with high BMI had worse prognosis than women with low BMI (hazard ratio 1.70; 95% CI 1.04–2.77), but PD was not associated with the hazard rate. Among screen-detected cancers, neither BMI nor PD was associated with the hazard rate.

Conclusions

In conclusion, high BMI was associated with the risk of having a tumor larger than 2 cm at diagnosis. Among women with interval cancer, high BMI was associated with worse prognosis. We believe that women with high BMI should be especially encouraged to attend screening.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-0962-6) contains supplementary material, which is available to authorized users.

Adipocyte/breast cancer cell crosstalk in obesity interferes with the anti-proliferative efficacy of tamoxifen

Background

Obesity is a well-known risk factor of breast cancer in post-menopausal women that also correlates with a diminished therapeutic response. The influence of adipocytes and their secretome, i.e. adipokines, on the efficacy of hormone therapy has yet to be elucidated.

Methods

We investigated, ex vivo, whether mature adipocytes, differentiated from adipose stem cells of normal-weight (MA20) or obese (MA30) women, and their secretions, were able to counteract the effects of tamoxifen (Tx) which is known to decrease neoplastic cell proliferation.

Results

In a tridimensional model and in a model of co-culture, the anti-proliferative effect of Tx on MCF-7 cancer cells was counteracted by MA30. These two models highlighted two different specific gene expression profiles for genes encoding cytokines or involved in angiogenesis based on the adipocyte microenvironment and the treatment. Thus it notably showed altered expression of genes such as TNFα that correlated with IL-6. In addition, leptin, IL-6 and TNFα, at concentrations reflecting plasma concentrations in obese patients, decreased the anti-proliferative efficacy of 4-hydroxytamoxifen (a major active metabolite of Tx).

Conclusions

These findings bring insights on adipocytes and mammary cancer cell interactions in Tx therapy, particularly in overweight/obese people. Indeed, patient’ adipokine status would give valuable information for developing individual strategies and avoid resistance to treatment.

Obesity and breast cancer outcomes in chemotherapy patients in New Zealand - a population-based cohort study

BACKGROUND

Obesity has been reported as an adverse prognostic factor in breast cancer, but inconsistently, and under-treatment with chemotherapy may occur. We provide the first assessment of obesity and breast cancer outcomes in a population-based, multi-ethnic cohort of New Zealand patients treated with chemotherapy.

METHODS

All 3536 women diagnosed with invasive breast cancer in the Waikato region of New Zealand from 2000-2014 were registered and followed until last follow-up in specialist or primary care, death or Dec 2014; median follow-up 4.1 years. For the 1049 patients receiving chemotherapy, mortality from breast cancer, other causes, and all causes, and rates of loco-regional and of distant recurrence, were assessed by body mass index (BMI), recorded after diagnosis, adjusting for other clinico-pathological and demographic factors by Cox regression.

RESULTS

BMI was known for 98% (n=1049); 33% were overweight (BMI 25-29.9), 21% were obese (BMI 30-34.9), and 14% were very obese (BMI 35+). There were no significant associations between obesity and survival, after adjustment for demographic and clinical factors (hazard ratios, HR, for very obese compared to BMI 21-24, for breast cancer deaths 0.96 (0.56-1.67), and for all deaths 1.03 (0.63-1.67), respectively, and only small non-significant associations for loco-regional or metastatic recurrence rates (HR 1.17 and 1.33 respectively). Subgroup analyses by age, menopausal status, ethnicity, stage, post-surgical radiotherapy, mode of diagnosis, type of surgery, and receptor status, showed no associations. No associations were seen with BMI as a continuous variable. The results in all patients irrespective of treatment but with recorded BMI data (n=2296) showed similar results.

CONCLUSIONS

In this population, obesity assessed post-diagnosis had no effect on survival or recurrence, based on 1049 patients with chemotherapy treatment with follow-up up to 14 years.

Presence of circulating tumor cells is associated with metabolic-related variables in postoperative patients with early-stage breast cancer

Objective

Although circulating tumor cells (CTCs) have been well-established as promising prognostic biomarkers in both early breast cancer and metastatic settings, little is known regarding the prognostic relevance of CTCs in the long-term postoperative monitoring of patients with non-metastatic breast cancer (non-MBC). In this study, we investigated the associations of CTCs with clinicopathological features and metabolic-related variables, such as obesity and hyperglycemia.

Methods

In this retrospective study, we recruited 264 patients with postoperative stage I-III breast cancer at Guangdong General Hospital from January 2009 to December 2015. The prevalence and number of CTCs were assessed using the CellSearch System at a median time of 19.0 months [interquartile range (IQR), 7.8-33.0] after surgery. The CTC assay results were correlated with the clinicopathological features and metabolic-related variables. A multivariate logistic regression analysis was performed to further determine the independent predictors of CTCs.

Results

CTCs were detected in 10.6% of all patients. The positive rate of CTCs in patients with infiltrating ductal carcinoma was lower than that in patients with other pathological types (9.0% vs. 28.6%, P=0.020). More importantly, the presence of CTCs was correlated with blood glucose level (P=0.015) and high-density lipoprotein level (P=0.030). The multivariate logistic regression analysis showed that the pathological type [odds ratio (OR): 1.757, 95% CI: 1.021-3.023; P=0.042] and blood glucose level (OR: 1.218, 95% CI: 1.014-1.465; P=0.035) were independent predictors of the presence of CTCs.

Conclusions

This study revealed potential associations between CTCs and metabolic-related factors in Chinese patients with non-MBC and supports the hypothesis that metabolic dysfunction in breast cancer patients might influence the biological activity of metastatic breast cancer, leading to a higher prevalence of CTCs.