Obesity and Breast Cancer Prognosis: Evidence, Challenges, and Opportunities

Breast Cancer Risk After Bariatric Surgery and Influence of Insulin Levels: A Nonrandomized Controlled Trial

Importance

Obesity and insulin are risk factors for breast cancer, and retrospective studies suggest bariatric surgery reduces breast cancer risk in women. However, long-term prospective data on breast cancer risk after bariatric surgery and the role of baseline insulin levels are lacking.

Objective

To examine if bariatric surgery is associated with breast cancer incidence in women and if treatment benefit is modified by baseline insulin levels.

Design, Setting, and Participants

The Swedish Obese Subjects (SOS) study was a nonrandomized intervention trial designed to investigate the long-term effects of bariatric surgery on obesity-related mortality and morbidity. Study recruitment took place between 1987 and 2001, and median (IQR) follow-up time was 23.9 years (20.1-27.1) years. The study was conducted at 25 public surgical departments and 480 primary health care centers in Sweden and included 2867 women aged 37 to 60 years and with body mass index 38 or greater (calculated as weight in kilograms divided by height in meters squared).

Intervention

In the surgery group (n = 1420), 260 women underwent gastric banding, 970 vertical banded gastroplasty, and 190 gastric bypass. The remaining contemporaneously matched control individuals (n = 1447) received usual obesity care.

Main Outcome and Measures

Breast cancer, the main outcome of this secondary report, was not a predefined outcome in the SOS study. Breast cancer events were identified in the Swedish National Cancer Registry.

Results

The study population comprised 2867 women with a mean (SD) age of 48.0 (6.2) years. During follow-up, there were 154 breast cancer events, 66 in the surgery group and 88 in the usual care group, and a decreased risk of breast cancer was observed in the bariatric surgery group (hazard ratio [HR], 0.68; 95% CI, 0.49-0.94; P = .019; adjusted HR, 0.72; 95% CI, 0.52-1.01; P = .06). The surgical treatment benefit on breast cancer risk was greater in women with baseline insulin levels above the median 15.8 μIU/L (HR, 0.48; 95% CI, 0.31-0.74; P = .001; adjusted HR, 0.55; 95% CI, 0.35-0.86; P = .008) compared to those below (HR, 0.95; 95% CI, 0.59-1.53; P = .84; adjusted HR, 1.01; 95% CI, 0.61-1.66; P = .97; interaction P = .02).

Conclusions and Relevance

This prospective clinical trial indicated a reduced risk of breast cancer after bariatric surgery in women with obesity. The surgical treatment benefit was predominantly seen in women with hyperinsulinemia.

Trial Registration

ClinicalTrials.gov Identifier: NCT01479452.

Body adipose tissue depots and treatment outcomes for women with breast cancer: A systematic review

BACKGROUND & AIMS

Excessive adipose tissue is associated with poorer prognosis in women with breast cancer (BC). However, several body adiposity depots, such as visceral (VAT), subcutaneous (SAT), intermuscular (IMAT), and gluteofemoral adipose tissues (GFAT) may have heterogeneous metabolic roles and health effects in these patients. This systematic review aims to evaluate the impact of different body adipose tissue depots, assessed via computed tomography (CT), on treatment outcomes for women with BC. We hypothesize that distinct body adipose tissue depots may be associated differently with outcomes in patients with BC.

METHODS

A comprehensive bibliographical search was conducted using PubMed, Embase, Cochrane Library, Scopus, and Web of Science databases (until January 2024). The methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale.

RESULTS

The final sample comprised 23 retrospective studies (n = 12,462), with fourteen presenting good quality. A lack of standardization in CT body adipose tissue depots measurement and outcome presentation precluded quantitative analysis. Furthermore, most included studies had heterogeneous clinical characteristics. Survival and treatment response were the most prevalent outcomes. VAT (n = 19) and SAT (n = 17) were the most frequently evaluated depots and their increase was associated with worse outcomes, mainly in terms of survival. IMAT (n = 4) presented contradictory findings and a higher GFAT (n = 1) was associated with better outcomes.

CONCLUSION

This systematic review found an association between increased VAT and SAT with worse outcomes in patients with BC. However, due to the heterogeneity of the included studies, further research with homogeneous methodologies is necessary to better understand the impact of body adipose tissue depots on treatment outcomes. Such knowledge could lead to improved care for this patient population.

An Integrated Care Approach to Improve Well-Being in Breast Cancer Patients

BACKGROUND

Breast cancer (BC) treatment has recently been revolutionized by the introduction of newer targeted agents, that helped tailoring therapies around the single patient. Along with increased survival rates, a careful evaluation of diet, lifestyle habits, physical activity, emotional and psychological experiences linked to the treatment journey, is now mandatory. However, a true proposal for an omnicomprehensive and "integrative" approach is still lacking in literature.

METHODS

A scientific board of internationally recognized specialists throughout different disciplines designed a shared proposal of holistic approach for BC patients.

RESULTS

A narrative review, containing information on BC treatment, endocrinological and diet aspects, physical activity, rehabilitation, integrative medicine, and digital narrative medicine, was developed.

CONCLUSIONS

In the context of a patient-centered care, BC treatment cannot be separated from a patient's long-term follow-up and care, and an organized interdisciplinary collaboration is the future in this disease's cure, to make sure that our patients will live longer and better.

TRIAL REGISTRATION

NCT05893368: New Model for Integrating Person-based Care (PbC) in the Treatment of Advanced HER2-negative Breast Cancer (PERGIQUAL). Registration date: 29th May 2023.

Ginsenoside Rg3 overcomes tamoxifen resistance through inhibiting glycolysis in breast cancer cells

Tamoxifen (TAM) resistance poses a significant clinical challenge in human breast cancer and exhibits high heterogeneity among different patients. Rg3, an original ginsenoside known to inhibit tumor growth, has shown potential for enhancing TAM sensitivity in breast cancer cells. However, the specific role and underlying mechanisms of Rg3 in this context remain unclear. Aerobic glycolysis, a metabolic process, has been implicated in chemotherapeutic resistance. In this study, we demonstrate that elevated glycolysis plays a central role in TAM resistance and can be effectively targeted and overcome by Rg3. Mechanistically, we observed upregulation of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3), a key mediator of glycolysis, in TAM-resistant MCF-7/TamR and T-47D/TamR cells. Crucially, PFKFB3 is indispensable for the synergistic effect of TAM and Rg3 combination therapy, which suppresses cell proliferation and glycolysis in MCF-7/TamR and T-47D/TamR cells, both in vitro and in vivo. Moreover, overexpression of PFKFB3 in MCF-7 cells mimicked the TAM resistance phenotype. Importantly, combination treatment significantly reduced TAM-resistant MCF-7 cell proliferation in an in vivo model. In conclusion, this study highlights the contribution of Rg3 in enhancing the therapeutic efficacy of TAM in breast cancer, and suggests that targeting TAM-resistant PFKFB3 overexpression may represent a promising strategy to improve the response to combination therapy in breast cancer.

Modeling of Mouse Experiments Suggests that Optimal Anti-Hormonal Treatment for Breast Cancer is Diet-Dependent

Estrogen receptor positive breast cancer is frequently treated with anti-hormonal treatment such as aromatase inhibitors (AI). Interestingly, a high body mass index has been shown to have a negative impact on AI efficacy, most likely due to disturbances in steroid metabolism and adipokine production. Here, we propose a mathematical model based on a system of ordinary differential equations to investigate the effect of high-fat diet on tumor growth. We inform the model with data from mouse experiments, where the animals are fed with high-fat or control (normal) diet. By incorporating AI treatment with drug resistance into the model and by solving optimal control problems we found differential responses for control and high-fat diet. To the best of our knowledge, this is the first attempt to model optimal anti-hormonal treatment for breast cancer in the presence of drug resistance. Our results underline the importance of considering high-fat diet and obesity as factors influencing clinical outcomes during anti-hormonal therapies in breast cancer patients.

Induction of Fatty Acid Oxidation Underlies DNA Damage-Induced Cell Death and Ameliorates Obesity-Driven Chemoresistance

The DNA damage response is essential for preserving genome integrity and eliminating damaged cells. Although cellular metabolism plays a central role in cell fate decision between proliferation, survival, or death, the metabolic response to DNA damage remains largely obscure. Here, this work shows that DNA damage induces fatty acid oxidation (FAO), which is required for DNA damage-induced cell death. Mechanistically, FAO induction increases cellular acetyl-CoA levels and promotes N-alpha-acetylation of caspase-2, leading to cell death. Whereas chemotherapy increases FAO related genes through peroxisome proliferator-activated receptor α (PPARα), accelerated hypoxia-inducible factor-1α stabilization by tumor cells in obese mice impedes the upregulation of FAO, which contributes to its chemoresistance. Finally, this work finds that improving FAO by PPARα activation ameliorates obesity-driven chemoresistance and enhances the outcomes of chemotherapy in obese mice. These findings reveal the shift toward FAO induction is an important metabolic response to DNA damage and may provide effective therapeutic strategies for cancer patients with obesity.

Oscillatory Hypoxia Can Induce Senescence of Adipose-Derived Mesenchymal Stromal Cells Potentiating Invasive Transformation of Breast Epithelial Cells

Obesity is strongly associated with occurrence, metastasis, and resistance to therapy in breast cancers, which also exhibit high adipose content in the tumor microenvironment. Adipose tissue-derived mesenchymal stromal cells (ASCs) are recruited to breast cancer by many mechanisms, including hypoxia, and contribute to metastatic transition of the cancer. Breast cancers are characterized by regions of hypoxia, which can be temporally unstable owing to a mismatch between oxygen supply and consumption. Using a high-sensitivity nanopatterned stromal invasion assay, we found that ASCs could promote stromal invasion of not only breast cancer cell lines but also MCF10A1, a cell line derived from untransformed breast epithelium. RNA sequencing of MCF10A1 cells conditioned with medium from ASCs revealed upregulation of genes associated with increased cell migration, chemotaxis, and metastasis. Furthermore, we found that fluctuating or oscillating hypoxia could induce senescence in ASCs, which could result in an increased invasive potential in the treated MCF10A1 cells. These findings highlight the complex interplay within the breast cancer microenvironment, hypoxia, and the role of ASCs in transforming even non-cancerous breast epithelium toward an invasive phenotype, providing insights into early metastatic events.

Elevated extracellular matrix protein 1 in circulating extracellular vesicles supports breast cancer progression under obesity conditions

The cargo content in small extracellular vesicles (sEVs) changes under pathological conditions. Our data shows that in obesity, extracellular matrix protein 1 (ECM1) protein levels are significantly increased in circulating sEVs, which is dependent on integrin-β2. Knockdown of integrin-β2 does not affect cellular ECM1 protein levels but significantly reduces ECM1 protein levels in the sEVs released by these cells. In breast cancer (BC), overexpressing ECM1 increases matrix metalloproteinase 3 (MMP3) and S100A/B protein levels. Interestingly, sEVs purified from high-fat diet-induced obesity mice (D-sEVs) deliver more ECM1 protein to BC cells compared to sEVs from control diet-fed mice. Consequently, BC cells secrete more ECM1 protein, which promotes cancer cell invasion and migration. D-sEVs treatment also significantly enhances ECM1-mediated BC metastasis and growth in mouse models, as evidenced by the elevated tumor levels of MMP3 and S100A/B. Our study reveals a mechanism and suggests sEV-based strategies for treating obesity-associated BC.

The impact of BMI on breast cancer - an updated systematic review and meta-analysis

BACKGROUND

Breast cancer is the most frequent form of cancer in women all over the world. It is the main cause of cancer death and the most often diagnosed cancer in women in 140 of the world's 184 countries. The link between breast cancer risk and body mass index (BMI) has gotten increasing attention in recent years, although the results are still debatable. Therefore, the current systematic review and meta-analysis evaluate the impact of BMI on breast cancer.

METHODS

The current study was carried out as a systematic review and meta-analysis, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We systematically searched Cochrane, Google Scholar, PubMed, EMBASE and Scopus databases to identify eligible articles impact of BMI on breast cancer with the appropriate Medical Subject Headings (MeSH). The Newcastle-Ottawa checklist was used for the risk of assessment for the included studies. Meta-analysis was performed using Review Manager 5.3 software.

RESULTS

Forty-six studies were included in the current review, which met the selection criteria of the current review. Among included 46 studies in this review, 50% (n = 23) of the studies found the HER2 type of breast cancer followed by triple-negative and HR-positive. The obesity was significantly higher in the case group compared with the control group (P < .001). Heterogeneity between the 14 studies is medium (I2 = 72%). In this review, there was no significant relation between overweight and breast cancer in women (P > .05). Heterogenecity between the 14 studies is medium (I2 = 89%). However, after removing the publication bias a significant relation between overweightness and breast cancer in women (P = .0005) was observed.

CONCLUSION

Obese breast cancer patients are a specific type of patient. They are more likely to develop cancer. Their need to surgery and radiation may cause greater difficulties. Obesity and overweight in women greatly increase the risk of breast cancer, according to the findings of the current meta-analysis. To confirm these findings and understand the pathogenic pathways, more research is required.

Association between dietary inflammatory index and body fat percentage among newly diagnosed breast cancer patients

BACKGROUND

Obesity, particularly excessive body fat, is an established risk factor and substantial prognostic determinant in breast cancer. Recent studies suggested that diet-related inflammation plays a key role in obesity. This study aimed to determine the association between energy-adjusted dietary inflammatory index (E-DII) and body composition, particularly body fat percentage, among patients with newly diagnosed breast cancer.

MATERIALS AND METHODS

This cross-sectional study was conducted on 124 breast cancer outpatients within the first year of diagnosis and yet to commence oncological treatment. Body composition parameters [body weight, body mass index (BMI), body fat percentage, fat mass over fat-free mass ratio (FM/FFM), muscle mass, and visceral fat] were obtained using a bioelectrical impedance analyzer. Body fat percentage was categorized into two groups which were normal (<35%) and high (≥35%). The E-DII was calculated from the validated 165-items Food Frequency Questionnaire (FFQ) and categorized into three groups or tertiles. Multiple logistic regression analysis was used to determine the association between the E-DII and body fat percentage.

RESULTS

Mean body weight, body fat percentage, FM/FFM, and visceral fat increased as E-DII increased from the lowest tertile (T1) to the most pro-inflammatory tertile (T3) (p for trend <0.05). E-DII was positively associated with body fat percentage (OR 2.952; 95% CI 1.154-7.556; p = 0.024) and remained significant after adjustment for cancer stage, age, physical activity, ethnicity, smoking history, and presence of comorbidities. Compared to T1, participants in T3 had a significantly lower consumption of fiber, vitamin A, beta-carotene, vitamin C, iron, thiamine, riboflavin, niacin, vitamin B6, folic acid, zinc, magnesium, and selenium, but a higher intake of total fat, saturated fat, and monounsaturated fatty acids.

CONCLUSIONS

A higher E-DII was associated with increased body fat percentage, suggesting the potential of advocating anti-inflammatory diet to combat obesity among newly diagnosed breast cancer patients.

Identification of lysyl oxidase as an adipocyte-secreted mediator that promotes a partial mesenchymal-to-epithelial transition in MDA-MB-231 cells

Aim

Breast cancer (BC) is the most common cancer in women worldwide, where adiposity has been linked to BC morbidity. In general, obese premenopausal women diagnosed with triple-negative BC (TNBC) tend to have larger tumours with more metastases, particularly to the bone marrow, and worse prognosis. Previous work using a 3-dimensional (3D) co-culture system consisting of TNBC cells, adipocytes and the laminin-rich extracellular matrix (ECM) trademarked as Matrigel, demonstrated that adipocytes and adipocyte-derived conditioned media (CM) caused a partial mesenchymal-to-epithelial transition (MET). Given that MET has been associated with secondary tumour formation, this study sought to identify molecular mediators responsible for this phenotypic change.

Methods

Adipocytes were cultured with and without Matrigel, where semi-quantitative proteomics was used to identify proteins whose presence in the CM was induced or enhanced by Matrigel, which were referred to as adipocyte-secreted ECM-induced proteins (AEPs). The AEPs identified were assessed for association with prognosis in published proteomic datasets and prior literature. Of these, 4 were evaluated by the reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA), followed by a functional and MET marker analysis of 1 AEP on MDA-MB-231 cells grown on Matrigel or as monolayers.

Results

The 4 AEPs showed a positive correlation between protein expression and poor prognosis. RT-qPCR analysis reported no significant change in AEPs mRNA expression. However, lysyl oxidase (LOX) was increased in CM of ECM-exposed adipocytes. Recombinant LOX (rLOX) caused the mesenchymal MDA-MB-231 TNBC cells to form less branched 3D structures and reduced the expression of vimentin.

Conclusions

The data suggest that adipocyte-secreted LOX changes the mesenchymal phenotype of BC cells in a manner that could promote secondary tumour formation, particularly at sites high in adipocytes such as the bone marrow. Future efforts should focus on determining whether targeting LOX could reduce BC metastasis in obese individuals.

The impact of body mass index on survival endpoints among patients with metastatic urothelial carcinoma undergoing treatment with immune checkpoint inhibitors: A real-world multicenter analysis

BACKGROUND

Studies on the correlation between high body mass index (BMI) and extended survival among patients receiving immune checkpoint inhibitors (ICIs) have been made, although findings have shown variability. Our research explored the phenomenon of the "obesity paradox" in patients with metastatic urothelial carcinoma (mUC) undergoing treatment with ICIs.

MATERIALS AND METHODS

We conducted a retrospective analysis of patients diagnosed with mUC who received a minimum of one cycle of ICI treatment at two medical centers in Taiwan from September 2015 to January 2023. Features of patients' clinicopathologic factors, including age, sex, primary or metastatic location, treatment line, and BMI were examined. The primary outcome were overall survival (OS) and progression-free survival (PFS), which were assessed utilizing the Kaplan-Meier method. We employed the Cox-regression model to adjust for multiple covariates.

RESULTS

A total of 215 patients were included, with 128 (59.5%) being male, and the median age was 70 years. In the obese group (BMI ≥25 kg/m2 ), patients demonstrated significantly better median OS compared to the non-obese group (BMI <25 kg/m2 ) (21.9 vs. 8.3 months; p = 0.021). However, there was no significant difference in median PFS between the high and low BMI groups (4.7 vs. 2.8 months; p = 0.16). Post-hoc subgroup revealed a survival benefit from ICI treatment in male patients within the BMI ≥25 kg/m2 group (HR 0.49, 95% CI 0.30-0.81, p = 0.005).

CONCLUSION

Based on real-world data from the Asia-Pacific region, there appears to be a correlation between obesity and prolonged OS in patients receiving ICI treatment for mUC.

Liraglutide attenuates obese-associated breast cancer cell proliferation via inhibiting PI3K/Akt/mTOR signaling pathway

This study aims to explore the anti-proliferative, pro-apoptotic, and anti-migration activities of liraglutide (LGT) in MCF-7 breast cancer (BC) cells in subjects with obesity, particularly its effects on the PI3K/Akt/mTOR/AMPK pathway. The role of AMPK/SIRT-1, an essential regulator of adipokine production, in the effect of LGT on the production of adipose-derived adipokine was also assessed. MCF-7 cells were incubated in conditioned medium (CM) generated from adipose-derived stem cells (ADSCs) of obese subjects. MCF-7 cells were then treated with LGT for 72 h. Anti-proliferative, pro-apoptotic, and anti-migration activities were investigated using alamarBlue, annexin V stain, and scratch assay, respectively. Protein levels of phosphorylated PI3K, p-Akt, p-mTOR, and p-AMPK were investigated using immunoblotting. Levels of adipokines in ADSCs were determined using RT-PCR before and after transfection of ADSCs using the specific small interference RNA sequences for AMPK and SIRT-1. LGT evoked anti-proliferative, apoptotic, and potential anti-migratory properties on MCF-7 cells incubated in CM from obese ADSCs and significantly mitigated the activity of the PI3K/Akt/mTOR survival pathway-but not AMPK-in MCF-7 cells. Furthermore, the anti-proliferative effects afforded by LGT were similar to those mediated by LY294002 (PI3K inhibitor) and rapamycin (mTOR inhibitor). Our results reveal that transfection of AMPK/SIRT-1 genes did not affect the beneficial role of LGT in the expression of adipokines in ADSCs. In conclusion, LGT elicits anti-proliferative, apoptotic, and anti-migratory effects on BC cells in obese conditions by suppressing the activity of survival pathways; however, this effect is independent of the AMPK/SIRT1 pathway in ADSCs or AMPK in BC cells.

The prognostic impact of body mass index in breast cancer according to tumor subtype

PURPOSE

Several studies demonstrated that obesity and underweight were negatively associated with outcomes of breast cancer. However, the results are still controversial, and the impact of body mass index (BMI) on distant metastasis-free survival (MFS), which might directly affect mortality, was less well evaluated. Our study aimed to verify the prognostic effect of BMI in breast cancer.

METHODS

A retrospective analysis of 504 patients with stage I-III breast cancer who underwent surgery from January 2005 to December 2013 was performed. The patients were divided into three groups according to preoperative BMI: underweight <18.5 kg/m2, normal weight 18.5-24.9 kg/m2, and overweight ≥25 kg/m2. The association between body weight status and breast cancer recurrence was analyzed. Subgroup analysis by tumor subtype according to receptor status was also performed.

RESULTS

The median follow-up period was 88 months. For disease recurrence, histologic grade and human epidermal growth factor receptor 2 (HER2)-positivity were independent prognostic factors in multivariate analysis. Stage, histologic grade, HER2-positivity, and BMI status were independent prognostic factors for distant metastasis. In survival analysis, overweight and underweight were significant predisposing factors for MFS, but not for disease-free survival (DFS). In the estrogen receptor (ER)-positive group, overweight and underweight patients had significantly worse DFS and MFS than normal weight patients. In the ER-negative or HER2-positive group, BMI status had no significant association with DFS and MFS.

CONCLUSION

The prognostic role of BMI on the survival outcomes of patients with breast cancer was different by tumor subtype. In ER-positive patients, overweight and underweight statuses had a negative prognostic effect on DFS and MFS, respectively.

A remarkable response to palliative treatment in metastatic breast cancer: A case report and comprehensive literature review

The case report describes a patient with stage IV breast cancer which metastasized to the lungs. The patient's initial computed tomography (CT) scan revealed a malignant lesion in the upper outer quadrant of the left breast and multiple pulmonary nodules, suggesting pulmonary metastasis. After starting palliative chemotherapy with intravenous paclitaxel and subcutaneous injections of Herceptin, a follow-up CT scan 3 months after the initiation of treatment showed the disappearance of metastasis, and her cancer regressed to stage II breast cancer that could be surgically resected. This case report highlights the importance of timely and appropriate palliative treatment measures, which can lead to unexpected outcomes, such as the regression of metastatic lesions and the possibility of curative treatment in such advanced cancer.

The Effect of Adipocyte-Secreted Factors in Activating Focal Adhesion Kinase-Mediated Cell Signaling Pathway towards Metastasis in Breast Cancer Cells

Obesity-associated perturbations in the normal secretion of adipocytokines from white adipocytes can drive the metastatic progression of cancer. However, the association between obesity-induced changes in secretory factors of white adipocytes and subsequent transactivation of the downstream effector proteins impacting metastasis in breast cancer cells remains unclear. Focal adhesion kinase, a cytoplasmic signal transducer, regulates the biological phenomenon of metastasis by activating downstream targets such as beta-catenin and MMP9. Thus, the possible role of phosphorylated FAK in potentiating cancer cell migration was investigated. To elucidate this potential relationship, MCF7 (ER+), MDA-MB-231 (Triple Negative) breast cancer cells, and MCF-10A non-tumorigenic breast cells were exposed to in vitro murine adipocyte-conditioned medium derived from 3T3-L1 MBX cells differentiated to obesity with fatty acid supplementation. Our results show that the conditioned medium derived from these obese adipocytes enhanced motility and invasiveness of breast cancer cells. Importantly, no such changes were observed in the non-tumorigenic breast cells. Our results also show that increased FAK autophosphorylation was followed by increased expression of beta-catenin and MMP9 in the breast cancer cells when exposed to obese adipocyte-conditioned medium, but not in the MCF10A cells. These results indicate that adipocyte-derived secretory factors induced FAK activation through phosphorylation. This in turn increased breast cancer cell migration and invasion by activating its downstream effector proteins beta-catenin and MMP9.

Adipocyte regulation of cancer stem cells

Cancer stem cells (CSCs) are a highly tumorigenic subpopulation of the cancer cells within a tumor that drive tumor initiation, progression, and therapy resistance. In general, stem cell niche provides a specific microenvironment in which stem cells are present in an undifferentiated and self-renewable state. CSC niche is a specialized tumor microenvironment for CSCs which provides cues for their maintenance and propagation. However, molecular mechanisms for the CSC-niche interaction remain to be elucidated. We have revealed that adipsin (complement factor D) and its downstream effector hepatocyte growth factor are secreted from adipocytes and enhance the CSC properties in breast cancers in which tumor initiation and progression are constantly associated with the surrounding adipose tissue. Considering that obesity, characterized by excess adipose tissue, is associated with an increased risk of multiple cancers, it is reasonably speculated that adipocyte-CSC interaction is similarly involved in many types of cancers, such as pancreas, colorectal, and ovarian cancers. In this review, various molecular mechanisms by which adipocytes regulate CSCs, including secretion of adipokines, extracellular matrix production, biosynthesis of estrogen, metabolism, and exosome, are discussed. Uncovering the roles of adipocytes in the CSC niche will propose novel strategies to treat cancers, especially those whose progression is linked to obesity.

Gender differences in change of metabolic syndrome status and its components on all-cause and cause-specific mortalities: Over a decade follow-up study

BACKGROUND

Accumulating evidence suggests a close association between metabolic syndrome (MetS) and excess risk of mortality. However, whether the dynamic change of MetS and its components could affect cause-specific mortalities and how this relation could be influenced by gender is yet to be clarified.

METHODS AND RESULTS

In this longitudinal cohort, we entered 4904 Iranian adults>30 years (2820 women) from March-1999 and followed up until December-2018. MetS was determined using the joint interim societies (JIS) criteria. Due to change in MetS status over three years, we divided individuals into MetS-free, MetS-recovery, MetS-developed, and MetS-persistent groups. The same categories were defined for each MetS component. Multivariate Cox regression models were employed to compute the adjusted hazard ratios (HRs) and female-to-male relative HRs (F/M-RHRs) for risk of all-cause, cardiovascular (CV), non-CV, and cancer mortalities. To resolve reverse causation, mortalities during the first three years of follow-up were excluded. Subgroup analysis was conducted for non-diabetic and non-hypertensive participants. During 12.5 years of follow-up, 357 all-cause, 112 CV-, and 79 cancer-mortalities occurred. Compared to MetS-free, MetS-persistent raised all-cause- and CV-mortalities in both genders. Same association was found for non-diabetic (HR = 1.66 (1.03-3.00)) or non-hypertensive (HR = 1.89 (1.09-3.64)) women. Moreover, MetS-persistent women with neither hypertension nor diabetes had increased all-cause mortality risk by 88% (F/M-RHR = 3.99 (1.53-5.58)). Women with stable MetS had excess risk of cancer-mortality by 40% (F/M-RHR = 1.63 (1.02-5.06)). Generally, among both genders, recovery from MetS declined risk of mortality events. Regarding MetS components, persistent elevated fasting plasma glucose (FPG) was related to all-cause mortality in both genders, but with stronger association in women (F/M-RHR = 1.41 (1.11-2.49), and CV-mortality only in women (F/M-RHR = 3.04 (1.02-5.96). Both development and stable status of high blood pressure (BP) increased the risk of CV-mortality merely in women (F/M-RHR = 3.10 (0.60-6.87) and F/M-RHR = 3.24 (1.26-6.11), respectively). Development or recovery from each Triglyceride, HDL-C, and waist circumference variables did not solely affect risk of mortality events in both genders.

CONCLUSION

Stable status of MetS could increase risk of mortalities with an overall stronger association in women. Although elevated BP and FPG are the main drivers for mortality risk, MetS among women could carry the corresponding effect even in absence of hypertension and diabetes.

Effect of a lifestyle intervention program's on breast cancer survivors' cardiometabolic health: Two-year follow-up

The purpose of this study is to assess the cardiometabolic responses of a lifestyle intervention (LI) conducted at home among breast cancer (BC) survivors during the two years of COVID-19 pandemic. A 3-month LI focused on diet and exercise was performed on thirty BC survivors (women; stages 0-II; non-metastatic; aged 53.6 ± 7.6 years; non-physically active) with a risk factor related to metabolic/endocrine diseases. Anthropometrics, cardiorespiratory fitness (V ˙ O2max), physical activity level (PAL), adherence to the Mediterranean diet (MeDiet modified questionnaire), and several biomarkers (i.e., glycemia, insulin, insulin resistance [HOMA-IR] index, triglycerides, high- [HDL] and low- [LDL] density lipoproteins, total cholesterol, progesterone, testosterone, and hs-troponin) were evaluated before and 3-, 6-, 12-, and 24-month after the LI. Beneficial effects of the LI were observed on several variables (i.e., body mass index, waist circumference, MeDiet, PAL, V ˙ O2max, glycemia, insulin, HOMA-IR index, LDL, total cholesterol, triglycerides, testosterone) after 3-month. The significant effect on Mediterranean diet adherence and V ˙ O2max persisted up to the 24-month follow-up. Decreases in HOMA-IR index and triglycerides were observed up to 12-month, however did not persist afterward. This study provides evidence on the positive association between LI and cardiometabolic health in BC survivors.

Breast-conserving surgery is an appropriate procedure for centrally located breast cancer: a population-based retrospective cohort study

BACKGROUND

The evidence of breast-conserving therapy (BCT) applied in centrally located breast cancer (CLBC) is absent. This study aims to investigate the long-term survival of breast-conserving therapy (BCT) in centrally located breast cancer (CLBC) compared with mastectomy in CLBC and BCT in non-CLBC.

METHODS

Two hundred ten thousand four hundred nine women with unilateral T1-2 breast cancer undergoing BCT or mastectomy were identified from the Surveillance, Epidemiology, and End Results database. Kaplan-Meier survival curves were assessed via log-rank test. Propensity score matching (PSM) was used to balance baseline features, and the multivariable Cox model was used to estimate the adjusted hazard ratio [HR] and its 95% confidence interval [CI] for breast cancer-specific survival (BCSS) and overall survival (OS).

RESULTS

With a median follow-up of 91 months, the BCSS and OS rates in patients who received BCT were greater than those patients treated with mastectomy in the entire CLBC set. Multivariable Cox analyses showed that CLBC patients who received BCT had better BCSS (HR = 0.67, 95%CI: 0.55-0.80, p < 0.001) and OS (HR = 0.78, 95%CI: 0.68-0.90, p = 0.001) than patients who received a mastectomy, but there were no significant differences of BCSS (HR = 0.65, 95%CI: 0.47-0.90, p = 0.009) and OS (HR = 0.82, 95%CI: 0.65-1.04, p = 0.110) after PSM. In patients treated with BCT, CLBC patients had a similar BCSS (HR = 0.99, 95%CI: 0.87-1.12, p = 0.850) but a worse OS (HR = 1.09, 95%CI: 1.01-1.18, p = 0.040) compared to that of the non-CLBC patient, but there was no significant difference both BCSS (HR = 1.05, 95%CI: 0.88-1.24, p = 0.614) and OS (HR = 1.08, 95%CI: 0.97-1.20, p = 0.168) after PSM.

CONCLUSION

Our findings revealed that BCT should be an acceptable and preferable alternative to mastectomy for well-selected patients with CLBC.

Age, Body Mass Index, Tumor Subtype, and Racial and Ethnic Disparities in Breast Cancer Survival

Importance

Black women in the United States have higher breast cancer (BC) mortality rates than White women. The combined role of multiple factors, including body mass index (BMI), age, and tumor subtype, remains unclear.

Objective

To assess the association of race and ethnicity with survival among clinical trial participants with early-stage BC (eBC) according to tumor subtype, age, and BMI.

Design, Setting, and Participants

This cohort study analyzed survival data, as of November 12, 2021, from participants enrolled between 1997 and 2010 in 4 randomized adjuvant chemotherapy trials: Cancer and Leukemia Group B (CALGB) 9741, 49907, and 40101 as well as North Central Cancer Treatment Group (NCCTG) N9831, legacy groups of the Alliance of Clinical Trials in Oncology. Median follow-up was 9.8 years.

Exposures

Non-Hispanic Black and Hispanic participants were compared with non-Hispanic White participants within subgroups of subtype (hormone receptor positive [HR+]/ERBB2 [formerly HER2] negative [ERBB2-], ERBB2+, and HR-/ERBB2-), age (<50, 50 to <65, and ≥65 years), and BMI (<18.5, 18.5 to <25.0, 25.0 to <30.0, and ≥30.0).

Main Outcomes and Measures

Recurrence-free survival (RFS) and overall survival (OS).

Results

Of 9479 participants, 436 (4.4%) were Hispanic, 871 (8.8%) non-Hispanic Black, and 7889 (79.5%) non-Hispanic White. The median (range) age was 52 (19.0-89.7) years. Among participants with HR+/ERBB2- tumors, non-Hispanic Black individuals had worse RFS (hazard ratio [HR], 1.49; 95% CI, 1.04-2.12; 5-year RFS, 88.5% vs 93.2%) than non-Hispanic White individuals, although the global test for association of race and ethnicity with RFS was not significant within any tumor subtype. There were no OS differences by race and ethnicity in any subtype. Race and ethnicity were associated with OS in young participants (age <50 years; global P = .008); young non-Hispanic Black participants (HR, 1.34; 95% CI, 1.04-1.71; 5-year OS, 86.6% vs 92.0%) and Hispanic participants (HR, 1.62; 95% CI, 1.16-2.29; 5-year OS, 86.2% vs 92.0%) had worse OS than young non-Hispanic White participants. Race and ethnicity were associated with RFS in participants with BMIs of 25 to less than 30, with non-Hispanic Black participants having worse RFS (HR, 1.81; 95% CI, 1.23-2.68; 5-year RFS, 83.2% vs 87.3%) than non-Hispanic White participants.

Conclusions and Relevance

In this cohort study, racial and ethnic survival disparities were identified in patients with eBC receiving standardized initial care, and potentially at-risk subgroups, for whom focused interventions may improve outcomes, were found.

Clinicopathologic characteristics and prognostic factors in patients with male breast cancer: A single tertiary center experience

BACKGROUND

The goal of this study was to assess the clinicopathologic characteristics and prognostic variables in men with breast cancer (BC).

METHODS

Clinical features, pathological characteristics, stage at diagnosis, and therapy data were noted. Survival analysis was performed using the log-rank technique and Cox regression model.

RESULTS

Eighty patients were included in the study. In 31% of the individuals, BRCA (BReast CAncer genes 1 and 2) mutations were identified. The estrogen receptor (ER) positivity ratio was 93.6%, whereas the progesterone receptor (PR) positivity ratio was 74.4%. In 16.9% of the cases, HER2 overexpression was found. The median survival time was 120.9 months (70.3-171.5), and the five-year overall survival (OS) ratio was 74.9%. In univariate analysis, BRCA mutation status had no effect on OS (P = 0.50). CA15-3 levels (P = 0.03) at diagnosis and history of smoking (P = 0.03) were significantly linked with OS. However, the multivariate analysis could not confirm these results.

CONCLUSIONS

We found that BRCA mutation, body mass index, a history of smoking, and alcohol consumption did not affect the OS in this research.

Addressing Inequalities in Breast Cancer Care Delivery

Breast cancer treatment, timeliness of care, and clinical outcomes are inferior for patients of Black race and Hispanic ethnicity, and the origin of these inequities is multifactorial. Owing to aggregate reporting of data in the United States for patients of Asian, Native Hawaiian, and Pacific Islander ancestry, disparities within and across these groups are difficult to appreciate. In large part due to low prevalence, male breast cancer remains understudied, and treatment algorithms are primarily extrapolated from research conducted in female patients.

The role of three-dimensional in vitro models in modelling the inflammatory microenvironment associated with obesity in breast cancer

Obesity is an established risk factor for breast cancer in postmenopausal women. However, the underlying biological mechanisms of how obesity contributes to breast cancer remains unclear. The inflammatory adipose microenvironment is central to breast cancer progression and has been shown to favour breast cancer cell growth and to reduce efficacy of anti-cancer treatments. Thus, it is imperative to further our understanding of the inflammatory microenvironment seen in breast cancer patients with obesity. Three-dimensional (3D) in vitro models offer a key tool in increasing our understanding of such complex interactions within the adipose microenvironment. This review discusses some of the approaches utilised to recapitulate the breast tumour microenvironment, including various co-culture and 3D in vitro models. We consider how these model systems contribute to the understanding of breast cancer research, with particular focus on the inflammatory tumour microenvironment. This review aims to provide insight and prospective future directions on the utility of such model systems for breast cancer research.

High-intensity interval training in breast cancer patients: A systematic review and meta-analysis

BACKGROUND

Women with breast cancer and improved survival often experience treatment-related impairments. High-intensity interval training (HIIT) has emerged as a promising exercise therapy modality for adult cancer patients. However, the overall effects of HIIT in breast cancer patients remain scarce and controversial. Therefore, we conducted a systematic review and meta-analysis to comprehensively evaluate the impact of HIIT on health-related outcomes in breast cancer patients.

METHODS

We searched the PubMed, Embase, and Web of Science from inception to November 7, 2022. Eligible studies included randomized controlled trials that compared HIIT interventions with usual care (UC) or MICT in breast cancer patients. The primary outcome assessed was physical fitness, and exploratory outcomes included body composition, blood-borne biomarkers, and patient-reported outcomes. Summary data were extracted, and standardized mean differences (SMD) were calculated for meta-analysis. For outcomes that could not be pooled, a systematic review was conducted.

RESULTS

Our analysis included 19 articles from 10 studies, encompassing 532 participants who met the inclusion criteria. Pooled results demonstrated that HIIT was superior to UC in improving peak oxygen uptake (VO2peak ). The SMD for VO2peak (L/min) and VO2peak (mL/kg/min) was 0.79 (95% CI 0.13, 1.45) and 0.59 (95% CI 0.01, 1.16), respectively. No significant differences in VO2peak were found between the HIIT and MICT groups. Meta-analyses on body composition and blood-borne biomarkers showed no significant differences between HIIT and UC. Systematic review indicated favorable effects of HIIT on muscle strength, fatigue, and emotional well-being.

CONCLUSIONS

HIIT is a time-efficient alternative to MICT for improving VO2peak and may also enhance muscle strength and alleviate fatigue and emotional symptoms in breast cancer patients. HIIT should be considered as an important component of exercise prescription in breast cancer care. Further studies with larger cohorts are needed to determine the clinical significance of HIIT-induced changes in terms of other outcomes in women with breast cancer.

Association of body mass index with clinicopathological features and survival in patients with primary invasive lobular breast cancer

PURPOSE

Invasive lobular carcinoma (ILC) represents up to 15% of all breast carcinomas. While the proportion of women with overweight and obesity increases globally, the impact of body mass index (BMI) at primary diagnosis on clinicopathological features of ILC and the prognosis of the patients has not been investigated yet.

PATIENTS AND METHODS

We performed a multicentric retrospective study including patients diagnosed with non-metastatic pure ILC. The association of BMI at diagnosis with clinicopathological variables was assessed using linear or multinomial logistic regression. Univariable and multivariable survival analyses were performed to evaluate the association of BMI with disease-free survival (DFS), distant recurrence-free survival (DRFS), and overall survival (OS).

RESULTS

The data of 2856 patients with ILC and available BMI at diagnosis were collected, of which 2570/2856 (90.0%) had oestrogen receptor (ER)-positive and human epidermal growth factor receptor (HER2) not amplified/overexpressed (ER+/HER2-) ILC. Of these 2570 patients, 80 were underweight (3.1%), 1410 were lean (54.9%), 712 were overweight (27.7%), and 368 were obese (14.3%). Older age at diagnosis, a higher tumour grade, a larger tumour size, a nodal involvement, and multifocality were associated with a higher BMI. In univariable models, higher BMI was associated with worse outcomes for all end-points (DFS: hazard ratio (HR) 1.21, 95CI 1.12-1.31, p value<0.01; DRFS: HR 1.25, 95CI 1.12-1.40, p value<0.01; OS: HR 1.25, 95CI 1.13-1.37, p value<0.01). This association was not statistically significant in multivariable analyses (DFS: HR 1.09, 95CI 0.99-1.20, p value 0.08; DRFS: HR 1.03, 95CI 0.89-1.20, p value 0.67; OS: HR 1.11, 95CI 0.99-1.24, p value 0.08), whereas grade, tumour size, and nodal involvement were still prognostic for all end-points.

CONCLUSION

Worse prognostic factors such as higher grade, larger tumour size, and nodal involvement are associated with higher BMI in ER+/HER2- ILC, while there was no statistical evidence for an independent prognostic role for BMI. Therefore, we hypothesise that the effect of BMI on survival could be mediated through its association with these clinicopathological variables.

A possible genetic association between obesity and colon cancer in females

Object

There is mounting clinical evidence that an increase in obesity is linked to an increase in cancer incidence and mortality. Although studies have shown a link between obesity and colon cancer, the particular mechanism of the interaction between obesity and colon cancer in females remains unknown. The goal of this work is to use bioinformatics to elucidate the genetic link between obesity and colon cancer in females and to investigate probable molecular mechanisms.

Methods

GSE44076 and GSE199063 microarray datasets were obtained from the Gene Expression Omnibus (GEO) database. In the two microarray datasets and healthy controls, the online tool GEO2R was utilized to investigate the differential genes between obesity and colon cancer. The differential genes (DEGs) identified in the two investigations were combined. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment studies were performed on the DEGs. The STRING database and Cytoscape software were then used to build protein-protein interaction (PPI) networks to discover hub genes. NetworkAnalyst was also used to build networks of target microRNAs (miRNAs) and hub genes, as well as networks of transcriptions.

Results

Between the two datasets, 146 DEGs were shared. The DEGs are primarily enriched in inflammatory and immune-related pathways, according to GO analysis and KEGG. 14 hub genes were identified via PPI building using the Cytoscape software's MCODE and CytoNCA plug-ins: TYROBP, CD44, BGN, FCGR3A, CD53, CXCR4, FN1, SPP1, IGF1, CCND1, MMP9, IL2RG, IL6 and CTGF. Key transcription factors for these hub genes include WRNIP1, ATF1, CBFB, and NR2F6. Key miRNAs for these hub genes include hsa-mir-1-3p, hsa-mir-26b-5p, hsa-mir-164a-5p and hsa-mir-9-5p.

Conclusion

Our research provides evidence that changed genes are shared by female patients with colon cancer and obesity. Through pathways connected to inflammation and the immune system, these genes play significant roles in the emergence of both diseases. We created a network between hub genes and miRNAs that target transcription factors, which may offer suggestions for future research in this area.

Novel Treatments for Obesity: Implications for Cancer Prevention and Treatment

It is now established that obesity is related to a higher incidence of cancer during a lifespan. The effective treatment of obesity opens up new perspectives in the treatment of a relevant modifiable cancer risk factor. The present narrative review summarizes the correlations between weight loss in obesity and cancer. The current knowledge between obesity treatment and cancer was explored, highlighting the greatest potential for its use in the treatment of cancer in the clinical setting. Evidence for the effects of obesity therapy on proliferation, apoptosis, and response to chemotherapy is summarized. While more studies, including large, long-term clinical trials, are needed to adequately evaluate the relationship and durability between anti-obesity treatment and cancer, collaboration between oncologists and obesity treatment experts is increasingly important.

Connecting the dots in the associations between diet, obesity, cancer, and microRNAs

The prevalence of obesity has reached pandemic levels worldwide, leading to a lower quality of life and higher health costs. Obesity is a major risk factor for noncommunicable diseases, including cancer, although obesity is one of the major preventable causes of cancer. Lifestyle factors, such as dietary quality and patterns, are also closely related to the onset and development of obesity and cancer. However, the mechanisms underlying the complex association between diet, obesity, and cancer remain unclear. In the past few decades, microRNAs (miRNAs), a class of small non-coding RNAs, have been demonstrated to play critical roles in biological processes such as cell differentiation, proliferation, and metabolism, highlighting their importance in disease development and suppression and as therapeutic targets. miRNA expression levels can be modulated by diet and are involved in cancer and obesity-related diseases. Circulating miRNAs can also mediate cell-to-cell communications. These multiple aspects of miRNAs present challenges in understanding and integrating their mechanism of action. Here, we introduce a general consideration of the associations between diet, obesity, and cancer and review the current knowledge of the molecular functions of miRNA in each context. A comprehensive understanding of the interplay between diet, obesity, and cancer could be valuable for the development of effective preventive and therapeutic strategies in future.

Identifying the effective behaviour change techniques in nutrition and physical activity interventions for the treatment of overweight/obesity in post-treatment breast cancer survivors: a systematic review

PURPOSE

Updated evidence for the treatment of obesity in cancer survivors includes behavioural lifestyle interventions underpinning at least one theoretical framework. The aim of this systematic review was to assess the effectiveness of theory-based lifestyle interventions for the treatment of overweight/obesity in breast cancer survivors and to report effective behavioural change techniques (BCTs) and components used in these interventions.

METHODS

Four databases were searched for RCTs published between database inception and July 2022. The search strategy included MeSH terms and text words, using the PICO-framework to guide the eligibility criteria. The PRISMA guidelines were followed. Risk-of-bias, TIDier Checklist for interventions' content, and the extent of behaviour change theories and techniques application were assessed. To evaluate the effectiveness of interventions, trials were categorised as "very," "quite," or "non" promising according to their potential to reduce body weight, and BCTs promise ratios were calculated to assess the potential of BCTs within interventions to decrease body weight.

RESULTS

Eleven RCTs met the inclusion criteria. Seven trials were classified as "very", three as "quite" and one study was "non" promising. Studies' size, design, and intervention strategies varied greatly, but the weight-loss goal in all studies was ≥ 5% of the initial body weight through a 500-1000 kcal/day energy deficit and a gradually increased exercise goal of ≥ 30 min/day. Social Cognitive Theory was the most commonly used theory (n = 10). BCTs ranged from 10 to 23 in the interventions, but all trials included behaviour goal setting, self-monitoring, instructions on the behaviour, and credible source. The risk-of-bias was "moderate" in eight studies and "high" in three.

CONCLUSION

The present systematic review identified the components of theory-based nutrition and physical activity behaviour change interventions that may be beneficial for the treatment of overweight/obesity in breast cancer survivors. The strategies mentioned, in addition to reported behavioural models and BCTs, should be considered when developing weight-loss interventions for breast cancer survivors.

The Molecular and Genetic Interactions between Obesity and Breast Cancer Risk

Breast cancer (BC) is considered the leading cause of death among females worldwide. Various risk factors contribute to BC development, such as age, genetics, reproductive factors, obesity, alcohol intake, and lifestyle. Obesity is considered to be a pandemic health problem globally, affecting millions of people worldwide. Obesity has been associated with a high risk of BC development. Determining the impact of obesity on BC development risk in women by demonstrating the molecular and genetic association in pre- and post-menopause females and risk to BC initiation is crucial in order to improve the diagnosis and prognosis of BC disease. In epidemiological studies, BC in premenopausal women was shown to be protective in a certain pattern. These altered effects between the two phases could be due to various physiological changes, such as estrogen/progesterone fluctuating levels. In addition, the relationship between BC risk and obesity is indicated by different molecular alterations as metabolic pathways and genetic mutation or epigenetic DNA changes supporting a strong connection between obesity and BC risk. However, these molecular and genetic alteration remain incompletely understood. The aim of this review is to highlight and elucidate the different molecular mechanisms and genetic changes occurring in obese women and their association with BC risk and development.

RAGE inhibition blunts insulin-induced oncogenic signals in breast cancer

The receptor for advanced glycation end products (RAGE) is implicated in diabetes and obesity complications, as well as in breast cancer (BC). Herein, we evaluated whether RAGE contributes to the oncogenic actions of Insulin, which plays a key role in BC progression particularly in obese and diabetic patients. Analysis of the publicly available METABRIC study, which collects gene expression and clinical data from a large cohort (n = 1904) of BC patients, revealed that RAGE and the Insulin Receptor (IR) are co-expressed and associated with negative prognostic parameters. In MCF-7, ZR75 and 4T1 BC cells, as well as in patient-derived Cancer-Associated Fibroblasts, the pharmacological inhibition of RAGE as well as its genetic depletion interfered with Insulin-induced activation of the oncogenic pathway IR/IRS1/AKT/CD1. Mechanistically, IR and RAGE directly interacted upon Insulin stimulation, as shown by in situ proximity ligation assays and coimmunoprecipitation studies. Of note, RAGE inhibition halted the activation of both IR and insulin like growth factor 1 receptor (IGF-1R), as demonstrated in MCF-7 cells KO for the IR and the IGF-1R gene via CRISPR-cas9 technology. An unbiased label-free proteomic analysis uncovered proteins and predicted pathways affected by RAGE inhibition in Insulin-stimulated BC cells. Biologically, RAGE inhibition reduced cell proliferation, migration, and patient-derived mammosphere formation triggered by Insulin. In vivo, the pharmacological inhibition of RAGE halted Insulin-induced tumor growth, without affecting blood glucose homeostasis. Together, our findings suggest that targeting RAGE may represent an appealing opportunity to blunt Insulin-induced oncogenic signaling in BC.

Associations of Post-Diagnosis Lifestyle with Prognosis in Women with Invasive Breast Cancer

BACKGROUND

Lifestyle habits can impact breast cancer development, but its impact on breast cancer prognosis remains unclear. We investigated associations of post-diagnosis lifestyle with mortality and recurrence in 1,964 women with invasive breast cancer enrolled in the Kaiser Permanente Northern California Pathways Study shortly after diagnosis with lifestyle information at baseline (2005-2013) and the 2-year follow-up.

METHODS

We calculated a post-diagnosis lifestyle score (range, 0-18) based on 9 diet, physical activity, and body weight recommendations from the American Cancer Society/American Society of Clinical Oncology (ACS/ASCO) using follow-up data (body weight also included baseline data); higher scores indicate greater guideline concordance. Similarly, we calculated a pre-diagnosis lifestyle score using baseline data to investigate pre- to post-diagnosis changes. We estimated hazard ratios (HR) and 95% confidence intervals (CI) using Cox proportional hazard models, with follow-up through December 2018 (observing 290 deaths and 176 recurrences).

RESULTS

The 2-year post-diagnosis lifestyle score was inversely associated with all-cause mortality (ACM; HR per 2-point increase = 0.90; 95% CI, 0.82-0.98), and breast cancer-related mortality (HR, 0.79; 95% CI, 0.67-0.95), but not recurrence. Relative to women who maintained low concordance with recommendations at both time points, women who maintained high concordance had a lower risk of ACM (HR, 0.61, 95% CI, 0.37-1.03). Improved concordance with some specific recommendations (particularly PA) may be associated with a lower hazard of ACM (HRPA, 0.52; 95% CI, 0.35-0.78).

CONCLUSIONS

Results suggest that women with breast cancer may benefit from a post-diagnosis lifestyle aligned with ACS/ASCO guidelines.

IMPACT

This information may potentially guide lifestyle recommendations for breast cancer survivors to reduce mortality risk.

Long-term outcomes of intraoperatively-placed applicator brachytherapy for rapid completion of breast conserving treatment: An analysis of a prospective registry data

Background and purpose

To evaluate the long-term outcome of accelerated partial breast irradiation utilizing intraoperatively placed applicator-based brachytherapy (ABB) in early-stage breast cancer.

Materials and methods

From our prospective registry, 223 patients with pTis-T2, pN0/pN1mic breast cancer were treated with ABB. The median treatment duration including surgery and ABB was 7 days. The prescribed doses were 32 Gy/8 fx BID (n = 25), 34 Gy/10 fx BID (n = 99), and 21 Gy/3 fx QD (n = 99). Endocrine therapy (ET) adherence was defined as completion of planned ET or ≥ 80% of the follow-up (FU) period. Cumulative incidence of ipsilateral breast tumor recurrence (IBTR) was estimated and influencing factors for IBTR-free survival rate (IBTRFS) were analyzed.

Results

218/223 patients had hormone receptor-positive tumors, including 38 (17.0%) with Tis and 185 (83.0%) with invasive cancer. After a median FU of 63 months, 19 (8.5%) patients had recurrence [17 (7.6%) with an IBTR]. Rates of 5-year IBTRFS and DFS were 92.2% and 91.1%, respectively. The 5-year IBTRFS rates were significantly higher for post-menopausal women (93.6% vs. 66.4%, p = 0.04), BMI < 30 kg/m2 (97.4% vs. 88.1%, p = 0.02), and ET-adherence (97.5% vs. 88.6%, p = 0.02). IBTRFS did not differ with dose regimens.

Conclusions

Postmenopausal status, BMI < 30 kg/m2, and ET- adherence predicted favorable IBTRFS. Our results highlight the importance of careful patient selection for ABB and encouragement of ET compliance.

CEBP-β and PLK1 as Potential Mediators of the Breast Cancer/Obesity Crosstalk: In Vitro and In Silico Analyses

Over the last two decades, obesity has reached pandemic proportions in several countries, and expanding evidence is showing its contribution to several types of malignancies, including breast cancer (BC). The conditioned medium (CM) from mature adipocytes contains a complex of secretes that may mimic the obesity condition in studies on BC cell lines conducted in vitro. Here, we report a transcriptomic analysis on MCF-7 BC cells exposed to adipocyte-derived CM and focus on the predictive functional relevance that CM-affected pathways/processes and related biomarkers (BMs) may have in BC response to obesity. CM was demonstrated to increase cell proliferation, motility and invasion as well as broadly alter the transcript profiles of MCF-7 cells by significantly modulating 364 genes. Bioinformatic functional analyses unraveled the presence of five highly relevant central hubs in the direct interaction networks (DIN), and Kaplan-Meier analysis sorted the CCAAT/enhancer binding protein beta (CEBP-β) and serine/threonine-protein kinase PLK1 (PLK1) as clinically significant biomarkers in BC. Indeed, CEBP-β and PLK1 negatively correlated with BC overall survival and were up-regulated by adipocyte-derived CM. In addition to their known involvement in cell proliferation and tumor progression, our work suggests them as a possible "deus ex machina" in BC response to fat tissue humoral products in obese women.

A Mathematical Model of the Disruption of Glucose Homeostasis in Cancer Patients

In this paper, we investigate the disruption of the glucose homeostasis at the whole-body level by the presence of cancer disease. Of particular interest are the potentially different responses of patients with or without hyperglycemia (including diabetes mellitus) to the cancer challenge, and how tumor growth, in turn, responds to hyperglycemia and its medical management. We propose a mathematical model that describes the competition between cancer cells and glucose-dependent healthy cells for a shared glucose resource. We also include the metabolic reprogramming of healthy cells by cancer-cell-initiated mechanism to reflect the interplay between the two cell populations. We parametrize this model and carry out numerical simulations of various scenarios, with growth of tumor mass and loss of healthy body mass as endpoints. We report sets of cancer characteristics that show plausible disease histories. We investigate parameters that change cancer cells' aggressiveness, and we exhibit differing responses in diabetic and non-diabetic, in the absence or presence of glycemic control. Our model predictions are in line with observations of weight loss in cancer patients and the increased growth (or earlier onset) of tumor in diabetic individuals. The model will also aid future studies on countermeasures such as the reduction of circulating glucose in cancer patients.

Obesity and Fibrosis: Setting the Stage for Breast Cancer

Obesity is a rising health concern and is linked to a worsened breast cancer prognosis. Tumor desmoplasia, which is characterized by elevated numbers of cancer-associated fibroblasts and the deposition of fibrillar collagens within the stroma, may contribute to the aggressive clinical behavior of breast cancer in obesity. A major component of the breast is adipose tissue, and fibrotic changes in adipose tissue due to obesity may contribute to breast cancer development and the biology of the resulting tumors. Adipose tissue fibrosis is a consequence of obesity that has multiple sources. Adipocytes and adipose-derived stromal cells secrete extracellular matrix composed of collagen family members and matricellular proteins that are altered by obesity. Adipose tissue also becomes a site of chronic, macrophage-driven inflammation. Macrophages exist as a diverse population within obese adipose tissue and mediate the development of fibrosis through the secretion of growth factors and matricellular proteins and interactions with other stromal cells. While weight loss is recommended to resolve obesity, the long-term effects of weight loss on adipose tissue fibrosis and inflammation within breast tissue are less clear. Increased fibrosis within breast tissue may increase the risk for tumor development as well as promote characteristics associated with tumor aggressiveness.

Obesity, cancer, and response to immune checkpoint inhibitors: Could the gut microbiota be the mechanistic link?

Immune checkpoint inhibitors (ICI) have deeply changed the therapeutic management of a broad spectrum of solid tumors. Recent observations showed that obese patients receiving ICIs might have better outcomes than those with normal weight, while obesity was historically associated with a worse prognosis in cancer patients. Of note, obesity is associated with alterations in the gut microbiome profile, which interacts with immune and inflammatory pathways, both at the systemic and intratumoral levels. As the influence of the gut microbiota on the response to ICI has been repeatedly reported, a specific gut microbiome profile in obese cancer patients may be involved in their better response to ICI. This review summarizes recent data on the interactions between obesity, gut microbiota, and ICIs. In addition, we highlight possible pathophysiological mechanisms supporting the hypothesis that gut microbiota could be one of the links between obesity and poor response to ICIs.

Inhibition of ERK signaling for treatment of ERRα positive TNBC

Breast cancer is the second leading cause of cancer-related deaths in women and triple-negative breast cancer (TNBC), in particular, is an aggressive and highly metastatic type of breast cancer that does not respond to established targeted therapies and is associated with poor prognosis and worse survival. Previous studies identified a subgroup of triple-negative breast cancer patients with high expression of estrogen related receptor alpha (ERRα) that has better prognosis when treated with tamoxifen. We therefore set out to identify common targets of tamoxifen and ERRα in the context of TNBC using phosphoproteomic analysis. In this study, we discovered that phosphorylation of mitogen-activated protein kinase 1 (MAPK1) is regulated by tamoxifen as well as ERRα. Additionally, we showed that inhibition of MAPK signaling together with the use of a selective ERRα inverse agonist, XCT-790, leads to a significant upregulation of apoptosis and paves way for the therapeutic use of MAPK inhibitors for treatment of ERRα expressing TNBC.

Clinical and Translational Applications of Serological and Histopathological Biomarkers in Metastatic Breast Cancer: A Comprehensive Review

Breast cancer is one of the most common malignancies worldwide and the most common form of cancer in women. A large proportion of patients begin with localized disease and undergo treatment with curative intent, while another large proportion of patients debuts with disseminated metastatic disease. In the last subgroup of patients, the prognosis in recent years has changed radically, given the existence of different targeted therapies thanks to the discovery of different biomarkers. Serological, histological, and genetic biomarkers have demonstrated their usefulness in the initial diagnosis, in the follow-up to detect relapses, to guide targeted treatment, and to stratify the prognosis of the most aggressive tumors in those with breast cancer. Molecular markers are currently the basis for the diagnosis of metastatic disease, given the wide variety of chemotherapy regions and existing therapies. These markers have been a real revolution in the therapeutic arsenal for breast cancer, and their diagnostic validity allows the classification of tumors with higher rates of relapse, aggressiveness, and mortality. In this sense, the existence of therapies targeting different molecular alterations causes a series of changes in tumor biology that can be assessed throughout the course of the disease to provide information on the underlying pathophysiology of metastatic disease, which allows us to broaden our knowledge of the different mechanisms of tissue invasion. Therefore, the aim of the present article is to review the clinical, diagnostic, predictive, prognostic utility and limitations of the main biomarkers available and under development in metastatic breast cancer.

Prognostic and clinical impact of the endocrine resistance/sensitivity classification according to international consensus guidelines for advanced breast cancer: an individual patient-level analysis from the Mammella InterGruppo (MIG) and Gruppo Italiano Mammella (GIM) studies

Background

Prior exposure to adjuvant endocrine therapy (ET) and timing to recurrence are crucial factors for first-line treatment choices in patients with hormone receptor-positive/HER2-negative (HR+/HER2-) breast cancer (BC) and in clinical trial eligibility, classifying metastatic HR+/HER2- BC as endocrine sensitive (ES) or primary (1ER)/secondary (2ER) resistant. However, this classification is largely based on expert opinion and no proper evidence exists to date to support its possible prognostic and clinical impact.

Methods

This analysis included individual patient-level data from 4 adjuvant phase III randomized trials by the Mammella InterGruppo (MIG) and Gruppo Italiano Mammella (GIM) study groups. The impact of endocrine resistance/sensitivity classification on overall survival (mOS, defined as time between date of distant relapse and death) was assessed in both univariate and multivariate Cox proportional hazards models.

Findings

Between November 1992 and July 2012, 9058 patients were randomized in 4 trials, of whom 6612 had HR+/HER2- BC. Median follow-up was 9.1 years (interquartile range [IQR] 5.6-15.0). In the whole cohort, disease-free survival and OS were 90.4% and 96.6% at 5 years, and 79.1% and 89.4% at 10 years, respectively. The estimated hazard of recurrence raised constantly during the first 15 years from diagnosis, being more pronounced during the first 2 years and less pronounced after year 7. Among the 493 patients with a distant relapse as first disease-free survival event and available date on ET completion, 72 (14.6%), 207 (42.0%) and 214 (43.4%) were classified as having 1ER, 2ER and ES, respectively. Median follow-up from diagnosis of a distant relapse was 3.8 years (IQR 1.6-7.5). Patients with 1ER were significantly more likely to be younger, to have N2/N3 nodal status, grade 3 tumours and to develop visceral metastases. Site of first distant relapse was significantly different between the 3 groups (p = 0.005). In patients with 1ER, 2ER and ES breast cancer, median mOS was 27.2, 38.4 and 43.2 months, respectively (p = 0.03). As compared to patients with ES disease, a higher risk of death was observed in those with 1 ER (adjusted Hazard Ratio [aHR] 1.54; 95% CI 1.03-2.30) and 2ER (aHR 1.17; 95% CI 0.87-1.56) (p = 0.11).

Interpretation

This large analysis with long-term follow-up provides evidence on the prognostic and clinical impact of the currently adopted endocrine resistance/sensitivity classification in patients with HR+/HER2- advanced BC. This classification may be considered a valid tool to guide clinical decision-making and to design future ET trials in the metastatic setting.

Funding

AIRC.

The association between body fatness and mortality among breast cancer survivors: results from a prospective cohort study

Evidence linking body fatness to breast cancer (BC) prognosis is limited. While it seems that excess adiposity is associated with poorer BC survival, there is uncertainty over whether weight changes reduce mortality. This study aimed to assess the association between body fatness and weight changes pre- and postdiagnosis and overall mortality and BC-specific mortality among BC survivors. Our study included 13,624 BC survivors from the European Prospective Investigation into Cancer and Nutrition (EPIC) study, with a mean follow-up of 8.6 years after diagnosis. Anthropometric data were obtained at recruitment for all cases and at a second assessment during follow-up for a subsample. We measured general obesity using the body mass index (BMI), whereas waist circumference and A Body Shape Index were used as measures of abdominal obesity. The annual weight change was calculated for cases with two weight assessments. The association with overall mortality and BC-specific mortality were based on a multivariable Cox and Fine and Gray models, respectively. We performed Mendelian randomization (MR) analysis to investigate the potential causal association. Five-unit higher BMI prediagnosis was associated with a 10% (95% confidence interval: 5-15%) increase in overall mortality and 7% (0-15%) increase in dying from BC. Women with abdominal obesity demonstrated a 23% (11-37%) increase in overall mortality, independent of the association of BMI. Results related to weight change postdiagnosis suggested a U-shaped relationship with BC-specific mortality, with higher risk associated with losing weight or gaining > 2% of the weight annually. MR analyses were consistent with the identified associations. Our results support the detrimental association of excess body fatness on the survival of women with BC. Substantial weight changes postdiagnosis may be associated with poorer survival.

The Future of Breast Cancer Research in the Survivorship Field

Prevalence of survivors of breast cancer has been steadily increasing in the last 20 years. Currently, more than 90% of women diagnosed with early-stage breast cancer are expected to be alive at 5 years from diagnosis thanks to early detection and breakthrough innovations in multimodal treatment strategies. Alongside this advancement in clinical outcomes, survivors of breast cancer might experience several specific challenges and present with unique needs. Survivorship trajectories after diagnosis and treatment of breast cancer can be significantly impacted by long-lasting and severe treatment-related side effects, including physical problems, psychological distress, fertility issues in young women, and impaired social and work reintegration, which add up to patients' individual risk of cancer recurrence and second primary malignancies. Alongside cancer-specific sequelae, survivors still present with general health needs, including management of chronic preexisting or ensuing conditions. Survivorship care should implement high-quality, evidence-based strategies to promptly screen, identify, and address survivors' needs in a comprehensive way and minimize the impact of severe treatment sequelae, preexisting comorbidities, unhealthy lifestyles, and risk of recurrence on quality of life. This narrative review focuses on core areas of survivorship care and discuss the state of the art and future research perspectives in key domains including selected long-term side effects, surveillance for recurrences and second cancers, well-being promotion, and specific survivors' needs.

Measurement of body composition by DXA, BIA, Leg-to-leg BIA and near-infrared spectroscopy in breast cancer patients - comparison of the four methods

BACKGROUND & AIMS

Body composition plays a crucial role in therapy adherence and the prognosis of cancer patients. The aim of this work was to compare four measurement methods for determining body composition regarding their validity, reliability and practicability in order to be able to draft a practical recommendation as to which method is most suitable as a standard measurement method in oncology.

METHODS

Fat mass (FM) and fat-free mass (FFM) was estimated for 100 breast cancer patients with ages of 18-70 years during a defined 20-week inpatient and outpatient rehabilitation process after primary therapy or follow-up rehabilitation. The four methods used were dual energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), leg-to-leg BIA and near-infrared spectroscopy (NIRS). At baseline (t0) and after 20 weeks (t20) the agreement between the four body composition analysis methods was quantified by pairwise method comparisons using Bland-Altman bias and limits of agreement estimates, t-tests and Lin's concordance correlation coefficients (CCCs).

RESULTS

CCCs and Bland-Altman plots indicated that DXA and BIA, DXA and NIRS as well as BIA and NIRS showed an excellent agreement concerning FM estimation at both time points (CCC>0.9). In contrast, no methods agreed with a CCC higher than 0.9 with respect to FFM estimation. However, most estimates were also significantly different between two methods, except for BIA and NIRS which yielded comparable FFM and FM estimates at both time points, albeit with large 95% limits of agreement intervals. The agreement between DXA and BIA was best in the lowest BMI tertile and worsened as BMI increased. Significant differences were also found for FFM changes measured with DXA versus BIA (mean difference -0.4 kg, p = 0.0049), DXA versus to Leg-to-leg BIA (-0.6 kg, p = 0.00073) and for FM changes measured with DXA versus Leg-to-leg BIA (0.5 kg, p = 0.0011).

CONCLUSIONS

For accurate and valid body composition estimates, Leg-to-leg BIA cannot be recommended due to its significant underestimation of FM or significant overestimation of FFM, respectively. BIA and NIRS results showed good agreement with the gold standard DXA. Therefore both measurement methods appear to be very well suitable to assess body composition of oncological patients and should be used more frequently on a routine basis to monitor the body composition of breast cancer patients.

Analysis of circulating extracellular vesicle derived microRNAs in breast cancer patients with obesity: a potential role for Let-7a

BACKGROUND

The incidence of obesity, a known risk factor for several metabolic and chronic diseases, including numerous malignancies, has risen sharply in the world. Various clinical studies demonstrate that excessive Body Mass Index (BMI) may worsen the incidence, prognosis, and mortality rates of breast cancer. Thus, understanding the link tying up obesity and breast cancer onset and progression is critically important, as it can impact patients' survival and quality of life. Recently, circulating extracellular vesicle (EV) derived miRNAs have attracted much attention for their diagnostic, prognostic and therapeutic potential in oncology research. Although the potential role of EV-derived miRNAs in the early detection of breast cancer has been repeatedly mentioned, screening of miRNAs packaged within serum EVs has not yet been reported in patients with obesity.

METHODS

Circulating EVs were isolated from normal weight (NW), and overweight/obese (OW/Ob) breast cancer patients and characterized by Transmission Electron Microscopy (TEM), Nanoparticle Tracking Analysis (NTA), and protein marker expression. Evaluation of EV-associated miRNAs was conducted in a screening (RNA-seq) and a validation (qRT-PCR) cohort. Bioinformatic analysis was performed to uncover significantly enriched biological processes, molecular functions and pathways. ROC and Kaplain-Meier survival analyses were used for clinical significance.

RESULTS

Comparison of serum EV-derived miRNAs from NW and OW/Ob patients detected seven differentially expressed miRNAs (let-7a-5p, miR-122-5p, miR-30d-5p, miR-126-3p, miR-27b-3p, miR-4772-3p, and miR-10a-5p) in the screening cohort. GO analysis revealed the enrichment of protein phosphorylation, intracellular signal transduction, signal transduction, and vesicle-mediated transport among the top biological processes. In addition, the target genes were significantly enriched in pathways related to PI3K/Akt, growth hormones, and insulin signalings, which are all involved in obesity-related diseases and/or breast cancer progression. In the validation cohort, qRT-PCR confirmed a significant down-regulation of EV-derived let-7a in the serum of OW/Ob breast cancer patients compared to NW patients. Let-7a levels also exhibited a negative correlation with BMI values. Importantly, decreased let-7a miRNA expression was associated with higher tumor grade and poor survival in patients with breast cancer.

CONCLUSION

These results suggest that serum-EV derived miRNAs may reflect a differential profile in relation to a patient's BMI, which, once validated in larger cohorts of patients, could provide insights into novel specific biomarkers and innovative targets to prevent the progression of obesity-mediated breast cancer.

A mathematical model of the disruption of glucose homeostasis in cancer patients

In this paper we investigate the disruption of the glucose homeostasis at the whole-body level by the presence of cancer disease. Of particular interest are the potentially different responses of patients with or without hyperglycemia (including Diabetes Mellitus) to the cancer challenge, and how tumor growth, in turn, responds to hyperglycemia and its medical management. We propose a mathematical model that describes the competition between cancer cells and glucosedependent healthy cells for a shared glucose resource. We also include the metabolic reprogramming of healthy cells by cancer-cell-initiated mechanism to reflect the interplay between the two cell populations. We parametrize this model and carry out numerical simulations of various scenarios, with growth of tumor mass and loss of healthy body mass as endpoints. We report sets of cancer characteristics that show plausible disease histories. We investigate parameters that change cancer cells’ aggressiveness, and we exhibit differing responses in diabetic and non-diabetic, in the absence or presence of glycemic control. Our model predictions are in line with observations of weight loss in cancer patients and the increased growth (or earlier onset) of tumor in diabetic individuals. The model will also aid future studies on countermeasures such as the reduction of circulating glucose in cancer patients.

Diet and physical activity interventions in Black and Latina women with breast cancer: A scoping review

Background

A growing number of lifestyle interventions are being developed to promote weight loss and adoption of a healthful lifestyles among breast cancer survivors; yet Black and Latina women remain underrepresented.

Purpose

We performed a scoping review of the available peer-reviewed literature to describe and compare the content, design, methods, and primary outcomes of current diet and/or physical activity (PA) interventions after a breast cancer diagnosis among Black and Latina women.

Methods

We queried PubMed, EMBASE, CINAHL, MEDLINE, and Clinicaltrials.gov up to October 1, 2022, to identify all randomized controlled trials of diet and/or PA after diagnosis of breast cancer with a majority (&gt;50%) of Black or Latina participants.

Results

Twenty-two randomized controlled trials were included in this review (five efficacy, twelve pilot, five on-going). Nine trials were among Latinas (two diet, four PA, and three diet/PA), six among Blacks (one PA and five diet/PA) and seven included both populations (five PA and two diet/PA), all of which examined different endpoints. Two of the five efficacy studies achieved their a priori outcome (one diet trial improved short term dietary intake; one PA trial achieved clinically significant improvements in metabolic syndrome score), both in Latinas. Eight pilot trials intervened on both diet and PA and three of them found favorable behavioral changes. Three (two for Latinas and one for Blacks) out of the nine diet and PA trials and three (all for Latinas) efficacy trials incorporated a culturally focused approach (i.e., traditional foods, music, Spanish content, bicultural health coaches, spirituality). Overall, four trials, including one efficacy trial, had one-year follow-up data, with three finding sustained behavior change. Electronic/mobile components were incorporated in five trials and one involved informal care givers. Most of the trials were geographically limited to the Northeast USA (n=8, NY, NC, DC, NJ) and Texas (n=4).

Conclusions

Most of the trials we identified were pilot or feasibility studies and of short duration, demonstrating the need for large randomized controlled efficacy lifestyle interventions among Black and Latina breast cancer survivors. Culturally tailored programing was limited but is an important component to incorporate in future trials in these populations.

Tackling the adverse health effects of excess body fat in breast cancer: where does physical activity fit in?

Weight gain is commonly observed during and after breast cancer treatment due to chemotherapy and endocrine therapies, induced menopause, changes in metabolism and food intake and decreased physical activity. Systematic reviews show that women who are overweight or obese at diagnosis, and those who gain weight, have poorer breast cancer survival outcomes than women of a healthy weight, irrespective of menopausal status. Excess body weight after breast cancer also increases the risk of type 2 diabetes mellitus and CVD. The adverse impact of excess body weight on survival outcomes is clearly shown for women with oestrogen receptor-positive (ER+) breast cancer, which accounts for 70 % of all breast cancer cases. Higher body fat is thought to increase the risk of ER+ recurrence because of increased aromatase activity. However, this could be compounded by other risk factors, including abnormal insulin and adipokine metabolism, impaired anti-tumour immunity and chronic low-grade systemic inflammation. Observational evidence linking poorer survival outcomes with excess body fat and low physical activity in women recovering from early-stage curative-intent breast cancer treatment is reviewed, before reflecting on the proposed biological mechanisms. The issues and sensitivities surrounding exercise participation amongst overweight breast cancer patients is also discussed, before providing an overview of the co-design process involved in development of an intervention (support programme) with appropriate content, structure and delivery model to address the weight management challenges faced by overweight ER+ breast cancer patients.