Metabolic syndrome and outcomes following early-stage breast cancer

Metabolic Syndrome and Risks of Breast Cancer Outcomes for Luminal, Triple-Negative, and HER2-Overexpressing Subtypes

BACKGROUND

We evaluated the association between metabolic syndrome (MetS; obesity plus two metabolic risk factors) and breast cancer outcomes according to molecular subtype.

METHODS

This population-based prospective cohort consisted of 3,267 women ages 20 to 69 years diagnosed with a first primary invasive breast cancer from 2004 to 2015 in the Seattle-Puget Sound region. Breast cancer was categorized into three subtypes based on estrogen receptor (ER), progesterone receptor, and HER2 expression: luminal (ER+), triple-negative (ER-/progesterone receptor negative/HER2-), and HER2-overexpressing (H2E; ER-/HER2+) subtypes. We used time-varying Cox models to assess the association of prevalent and incident MetS with risks of recurrence, breast cancer-specific mortality (BCSM), and all-cause mortality (ACM).

RESULTS

MetS was associated with a greater risk of recurrence [HR, 3.24; 95% confidence interval (CI), 1.13-9.33] and BCSM (HR, 5.34; 95% CI, 2.32-12.31) only for the H2E subtype and greater risks of ACM for luminal (HR, 1.92; 95% CI, 1.37-2.68), H2E (HR, 5.09; 95% CI, 2.51-10.32), and all cases combined (HR, 1.90; 95% CI, 1.42-2.53). We also observed heterogeneity in recurrence and mortality outcomes across specific components of MetS and molecular subtypes.

CONCLUSIONS

MetS is associated with ACM among women with breast cancer and with BCSM among women with the H2E subtype.

IMPACT

These results highlight the importance of managing comorbidities to decrease the risk for adverse outcomes among breast cancer survivors.

Digital Rehabilitation Program for Breast Cancer Survivors on Adjuvant Hormonal Therapy: A Feasibility Study

Background: Breast cancer survivors often face physical and psychological challenges, including weight gain, metabolic syndrome, and reduced quality of life. To address these concerns, a mobile app-based rehabilitation program called "THRIVE" was developed to improve physical activity, medication adherence, and health-related quality of life (HRQoL) in this population. Methods: This prospective, single-arm study assessed the feasibility and effectiveness of the "THRIVE" app among breast cancer survivors undergoing hormonal therapy. Participants were recruited from Queen Mary Hospital in Hong Kong between December 2022 and June 2023. Eligible survivors had completed treatment within the last five years or had stable advanced disease on hormonal therapy. Participants monitored their exercise, medication adherence, and self-care via the app and a Fitbit activity tracker for 16 weeks. Primary outcomes included recruitment, dropout, adherence rates, and safety. Secondary outcomes, measured at baseline and week 16, included physical activity intensity, HRQoL, psychological stress, body composition, and app satisfaction. Results: A total of 50 participants, with a median age of 53 years, completed the study. The recruitment rate was 70.4% with no dropouts. The adherence rate, measured by completing exercises recommended in the mobile app at least three times per week, was 74%. No severe adverse events were reported. While physical activity intensity showed no significant changes from baseline to week 16 (p = 0.24), cognitive function (p = 0.021), future perspective (p = 0.044), arm symptoms (p = 0.042), depression (p = 0.01), and anxiety (p = 0.004) improved. All participants reported perfect medication compliance (100%). Satisfaction with the app was high. Conclusions: This mobile app-based rehabilitation program demonstrated good feasibility, with satisfactory recruitment, adherence, and safety, providing valuable insights into future definitive studies.

Metabolic Syndrome Is Associated With Poor Prognosis in Patients With Breast Cancer Receiving Neoadjuvant Therapy

PURPOSE

Few studies with a large sample size are available on patients with metabolic syndrome (MetS) receiving neoadjuvant treatment (NAT) for breast cancer. This study aimed to investigate the impact of MetS on the prognosis of patients with breast cancer undergoing NAT.

METHODS

The data of patients with breast cancer receiving NAT at our center from January 2017 to December 2019 were retrospectively analyzed. A chi-square test and logistic regression model were applied to ascertain the factors associated with MetS and pathological complete response (pCR). The Cox proportional risk model was employed for univariate and multivariate analyses of disease-free survival (DFS) and overall survival (OS).

RESULTS

Of the 910 patients enrolled, 164 (18.0%) were diagnosed with MetS, 568 (62.4%) with stage II, and 342 (37.6%) with stage III. Postmenopausal status (p = 0.045) and stage III (p = 0.009) were associated with a higher incidence rate of MetS. MetS was associated with a lower pCR rate (p = 0.027). The 5-year DFS (83.7% vs. 73.1%, p = 0.001) and OS (92.8% vs. 85.5%, p = 0.001) of the non-MetS group were significantly better than those of the MetS group. In premenopausal women, the DFS (p = 0.001) and OS (p = 0.025) of the non-MetS group were significantly better than those of the MetS group. No significant differences were noted in DFS (p = 0.270) or OS (p = 0.078) between the two groups in postmenopausal women. In the Cox proportional risk model, MetS acted as an independent factor associated with DFS (HR = 1.705, 95% CI: 1.201-2.421, p = 0.003) and OS (HR = 1.874, 95% CI: 1.149-3.055, p = 0.012).

CONCLUSION

MetS was associated with poor prognosis in patients with breast cancer receiving NAT. Hence, close attention should be paid to patients with breast cancer who have MetS.

Desmoglein 2 Functions as a Receptor for Fatty Acid Binding Protein 4 in Breast Cancer Epithelial Cells

Fatty acid binding protein 4 (FABP4) is a secreted adipokine linked to obesity and progression of a variety of cancers. Obesity increases extracellular FABP4 (eFABP4) levels in animal models and in obese breast cancer patients compared with lean healthy controls. Using MCF-7 and T47D breast cancer epithelial cells, we show herein that eFABP4 stimulates cellular proliferation in a time and concentration dependent manner while the non-fatty acid-binding mutant, R126Q, failed to potentiate growth. When E0771 murine breast cancer cells were injected into mice, FABP4 null animals exhibited delayed tumor growth and enhanced survival compared with injections into control C57Bl/6J animals. eFABP4 treatment of MCF-7 cells resulted in a significant increase in phosphorylation of extracellular signal-regulated kinase 1/2 (pERK), transcriptional activation of nuclear factor E2-related factor 2 (NRF2) and corresponding gene targets ALDH1A1, CYP1A1, HMOX1, SOD1 and decreased oxidative stress, while R126Q treatment did not show any effects. Proximity-labeling employing an APEX2-FABP4 fusion protein revealed several proteins functioning in desmosomes as eFABP4 receptor candidates including desmoglein (DSG), desmocollin, junction plankoglobin, desomoplankin, and cytokeratins. AlphaFold modeling predicted an interaction between eFABP4, and the extracellular cadherin repeats of DSG2 and pull-down and immunoprecipitation assays confirmed complex formation that was potentiated by oleic acid. Silencing of DSG2 in MCF-7 cells attenuated eFABP4 effects on cellular proliferation, pERK levels, and ALDH1A1 expression compared with controls.

IMPLICATIONS

These results suggest desmosomal proteins, and in particular desmoglein 2, may function as receptors of eFABP4 and provide new insight into the development and progression of obesity-associated cancers.

Time interval between breast cancer diagnosis and surgery is associated with disease outcome

Time interval between breast cancer (BC) diagnosis and surgery is of concern to patients and clinicians, but its impact on survival remains unclear. We identified 5130 BC patients receiving surgery between 2009 and 2017 from the Shanghai Jiaotong University Breast Cancer Database (SJTU-BCDB), and divided as Ruijin cohort and SJTU cohort. All participants were divided into three groups according to the interval between diagnosis and surgery: ≤ 1 week, 1-2 weeks, and > 2 weeks. Among 3144 patients of Ruijin cohort, the estimated 5-year breast cancer-free interval (BCFI) rates for the ≤ 1 week, 1-2 weeks and > 2 weeks groups were 91.8%, 87.5%, and 84.0% (P = 0.088), and the estimated 5-year overall survival (OS) rates were 95.6%, 89.6%, and 91.5% (P = 0.002). Multivariate analysis showed that patients with a TTS > 2 weeks had significantly lower BCFI (HR = 1.80, 95%CI 1.05-3.11, P = 0.034) and OS (HR = 2.07, 95% CI 1.04-4.13, P = 0.038) rates than patients with a TTS ≤ 1 week. Among 5130 patients when combining Ruijin cohort with SJTU cohort, the estimated 5-year BCFI rates for the ≤ 1 week, 1-2 weeks, and > 2 weeks groups were 91.0%, 87.9%, and 78.9%, and the estimated 5-year OS rates for the ≤ 1 week, 1-2 weeks, and > 2 weeks groups were 95.8%, 90.6%, and 91.5%, both with a significantly p value < 0.001. Our findings demonstrated the prolonged time to surgery (more than 2 weeks) after BC diagnosis was associated with poor disease outcomes, suggesting that efforts to early initiate treatment after diagnosis need to be pursued where possible to improve survival.

Identification of Metabolic Syndrome-Related miRNA-mRNA Regulatory Networks and Key Genes Based on Bioinformatics Analysis

Metabolic syndrome, which affects approximately one-quarter of the world's population, is a combination of multiple traits and is associated with high all-cause mortality, increased cancer risk, and other hazards. It has been shown that the epigenetic functions of miRNAs are closely related to metabolic syndrome, but epigenetic studies have not yet fully elucidated the regulatory network and key genes associated with metabolic syndrome. To perform data analysis and screening of potential differentially expressed target miRNAs, mRNAs and genes based on a bioinformatics approach using a metabolic syndrome mRNA and miRNA gene microarray, leading to further analysis and identification of metabolic syndrome-related miRNA-mRNA regulatory networks and key genes. The miRNA gene set (GSE98896) and mRNA gene set (GSE98895) of peripheral blood samples from patients with metabolic syndrome from the GEO database were screened, and set|logFC|> 1 and adjusted P < 0.05 were used to identify the differentially expressed miRNAs and mRNAs. Differentially expressed miRNA transcription factors were predicted using FunRich software and subjected to GO and KEGG enrichment analysis. Next, biological process enrichment analysis of differentially expressed mRNAs was performed with Metascape. Differentially expressed miRNAs and mRNAs were identified and visualized as miRNA-mRNA regulatory networks based on the complementary pairing principle. Data analysis of genome-wide metabolic syndrome-related mRNAs was performed using the gene set enrichment analysis (GSEA) database. Finally, further WGCNA of the set of genes most closely associated with metabolic syndrome was performed to validate the findings. A total of 217 differentially expressed mRNAs and 158 differentially expressed miRNAs were identified by screening the metabolic syndrome miRNA and mRNA gene sets, and these molecules mainly included transcription factors, such as SP1, SP4, and EGR1, that function in the IL-17 signalling pathway; cytokine-cytokine receptor interaction; proteoglycan syndecan-mediated signalling events; and the glypican pathway, which is involved in the inflammatory response and glucose and lipid metabolism. miR-34C-5P, which was identified by constructing a miRNA-mRNA regulatory network, could regulate DPYSL4 expression to influence insulin β-cells, the inflammatory response and glucose oxidative catabolism. Based on GSEA, metabolic syndrome is known to be closely related to oxidative phosphorylation, DNA repair, neuronal damage, and glycolysis. Finally, RStudio and DAVID were used to perform WGCNA of the gene sets most closely associated with metabolic syndrome, and the results further validated the conclusions. Metabolic syndrome is a common metabolic disease worldwide, and its mechanism of action is closely related to the inflammatory response, glycolipid metabolism, and impaired mitochondrial function. miR-34C-5P can regulate DPYSL4 expression and can be a potential research target. In addition, UQCRQ and NDUFA8 are core genes of oxidative phosphorylation and have also been identified as potential targets for the future treatment of metabolic syndrome.

Obesity and metabolic syndrome are associated with short-term endocrine therapy resistance in early ER + breast cancer

PURPOSE

Increased body mass index (BMI) and metabolic syndrome (MS) are associated with increased breast cancer recurrence risk. Whether this is due to intrinsic tumor biology or modifiable factors of the obese state remains incompletely understood.

METHODS

Oncotype DX Recurrence Scores of 751 patients were stratified by BMI to assess association with tumor-intrinsic recurrence risk. Cellular proliferation by Ki67 after 10-21 days of presurgical letrozole treatment was used to stratify endocrine therapy response (sensitive-ln(Ki67) < 1; intermediate-ln(Ki67)1-2; resistant-ln(Ki67) >  = 2). BMI at the time of surgery and MS variables were collected retrospectively for 143 patients to analyze association between therapy response and BMI/MS. Additionally, PI3K pathway signaling was evaluated by immunohistochemistry of phosphorylated Akt and S6.

RESULTS

There was no significant association between BMI and recurrence score (p = 0.99), and risk score distribution was similar across BMI groups. However, BMI was associated with short-term endocrine therapy resistance, with a significant enrichment of intermediate and resistant tumors in patients with obesity (55%, p = 0.0392). Similarly, the relative risk of an endocrine therapy-resistant tumor was 1.4-fold greater for patients with MS (p = 0.0197). In evaluating PI3K pathway mediators, we found patients with 3 or more MS criteria had more tumors with pAkt scores above the median (p = 0.0436). There were no significant differences in S6 activation.

CONCLUSION

Our findings suggest the association between obesity/metabolic syndrome and breast cancer recurrence is better reflected by response to treatment than tumor-intrinsic properties, suggesting interventions to reverse obesity and/or MS may improve outcomes for breast cancer recurrence.

Hypertension in Cancer Survivors

PURPOSE OF REVIEW

With increasing survival after cancer treatment, there is a need for long-term management of risk factors and chronic medical conditions to realize the full benefit of improvement of outcomes. Hypertension is a major risk factor for cardiovascular disease and has a higher prevalence in cancer survivors compared to the general population. In this review article, we discuss the burden of hypertension in cancer survivors and how this impacts their long-term outcomes and risk of cancer recurrence. We then discuss the latest concepts regarding the pathophysiology of hypertension in cancer survivors in detail. There is a focus on inflammation and the role it plays in cancer and hypertension followed by a brief discussion on clonal hematopoiesis of indeterminate potential (CHIP) and associated hypertension. There is a brief review of various cancer therapies associated with development and worsening of hypertension control and the underlying mechanisms behind this. We conclude the review article by giving recommendations on blood pressure control in this unique patient population.

RECENT FINDINGS

A lot of newer anti-cancer therapies have been implicated in the development or worsening of hypertension. We summarize the latest data, explore associations between these therapies and hypertension, and review the latest understanding of the underlying mechanisms driving this process. Hypertension is a major risk factor for cardiovascular disease in cancer survivors and must be recognized and treated promptly.

Translation initiation and its relationship with metabolic mechanisms in cancer development, progression and chemoresistance

Pathways that regulate protein homeostasis (proteostasis) in cells range from mRNA processing to protein degradation; perturbations in regulatory mechanisms of these pathways can lead to oncogenic cellular processes. Protein synthesis modulation failures are common phenomena in cancer cells, wherein specific conditions that promote the translation of protein factors promoting carcinogenesis are present. These specific conditions may be favored by metabolic lipid alterations like those found in metabolic syndrome and obesity. Protein translation modifications have been described in obesity, favoring the translation of protein targets that benefit lipid accumulation; a determining factor is the activity of the cap-binding eukaryotic translation initiation factor 4E (eIF4E), a crosstalk in protein translation and lipogenesis. Besides, alterations of protein translation initiation steps are critical participants for the development of both pathogenic conditions, cancer, and obesity. This chapter is focused on the regulation of recognition and processing of carcinogenic-mRNA and the connections among lipid metabolism and cell signaling pathways that promote oncogenesis, tumoral microenvironment generation and potentially the development of chemoresistance. We performed an in-depth analysis of events, such as those occurring in obesity and dyslipidemias, that may influence protein translation, driving the recognition of certain mRNAs and favoring cancer development and chemoresistance.

Cancer causes dysfunctional insulin signaling and glucose transport in a muscle-type-specific manner

Metabolic dysfunction and insulin resistance are emerging as hallmarks of cancer and cachexia, and impair cancer prognosis. Yet, the molecular mechanisms underlying impaired metabolic regulation are not fully understood. To elucidate the mechanisms behind cancer-induced insulin resistance in muscle, we isolated extensor digitorum longus (EDL) and soleus muscles from Lewis Lung Carcinoma tumor-bearing mice. Three weeks after tumor inoculation, muscles were isolated and stimulated with or without a submaximal dose of insulin (1.5 nM). Glucose transport was measured using 2-[³ H]Deoxy-Glucose and intramyocellular signaling was investigated using immunoblotting. In soleus muscles from tumor-bearing mice, insulin-stimulated glucose transport was abrogated concomitantly with abolished insulin-induced TBC1D4 and GSK3 phosphorylation. In EDL, glucose transport and TBC1D4 phosphorylation were not impaired in muscles from tumor-bearing mice, while AMPK signaling was elevated. Anabolic insulin signaling via phosphorylation of the mTORC1 targets, p70S6K thr389, and ribosomal-S6 ser235, were decreased by cancer in soleus muscle while increased or unaffected in EDL. In contrast, the mTOR substrate, pULK1 ser757, was reduced in both soleus and EDL by cancer. Hence, cancer causes considerable changes in skeletal muscle insulin signaling that is dependent on muscle-type, which could contribute to metabolic dysregulation in cancer. Thus, the skeletal muscle could be a target for managing metabolic dysfunction in cancer.

Cardiometabolic risk factors, physical activity, and postmenopausal breast cancer mortality: results from the Women's Health Initiative

BACKGROUND

Higher physical activity levels are associated with lower breast cancer-specific mortality. In addition, the metabolic syndrome is associated with higher breast cancer-specific mortality. Whether the physical activity association with breast cancer mortality is modified by number of metabolic syndrome components (cardiometabolic risk factors) in postmenopausal women with early-stage breast cancer remains unknown.

METHODS

Cardiovascular risk factors included high waist circumference, hypertension, high cholesterol, and diabetes. Breast cancers were verified by medical record review. Mortality finding were enhanced by serial National Death Index queries. Cox proportional hazards regression models were used to estimate associations between baseline physical activity and subsequent breast cancer-specific and overall mortality following breast cancer diagnosis in Women's Health Initiative participants. These associations were examined after stratifying by cardiometabolic risk factor group.

RESULTS

Among 161,308 Women's Health Initiative (WHI) participants, 8543 breast cancers occurred after 9.5 years (median) follow-up in women, additionally with information on cardiometabolic risk factors and physical activity at entry. In multi-variable analyses, as measured from cancer diagnosis, higher physical activity levels were associated with lower all-cause mortality risk (hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.78-0.95, trend P < 0.001) but not with breast cancer-specific mortality (HR 0.85, 95% CI 0.70 to 1.04, trend P = 0.09). The physical activity and all-cause mortality association was not significantly modified by cardiometabolic risk factor number.

CONCLUSIONS

Among women with early-stage breast cancer, although higher antecedent physical activity was associated with lower risk of all-cause mortality, the association did not differ by cardiometabolic risk factor number.

Metabolic Syndrome and Risk of Breast Cancer by Molecular Subtype: Analysis of the MEND Study

Metabolic syndrome is a cluster of biological irregularities that is a known risk factor for cardiovascular disease, stroke, and diabetes. In a case-control study of 555 West African women, we observed that metabolic syndrome was strongly associated with breast cancer and the aggressive triple-negative molecular subtype, highlighting a need for clinical and lifestyle interventions targeting metabolic syndrome to reduce breast cancer risk in this population.

Effect of a Remotely Delivered Weight Loss Intervention in Early-Stage Breast Cancer: Randomized Controlled Trial

Limited evidence exists on the effects of weight loss on chronic disease risk and patient-reported outcomes in breast cancer survivors. Breast cancer survivors (stage I-III; body mass index 25-45 kg/m²) were randomized to a 12-month, remotely delivered (22 telephone calls, mailed material, optional text messages) weight loss (diet and physical activity) intervention (n = 79) or usual care (n = 80). Weight loss (primary outcome), body composition, metabolic syndrome risk score and components, quality of life, fatigue, musculoskeletal pain, menopausal symptoms, fear of recurrence, and body image were assessed at baseline, 6 months, 12 months (primary endpoint), and 18 months. Participants were 55 ± 9 years and 10.7 ± 5.0 months post-diagnosis; retention was 81.8% (12 months) and 80.5% (18 months). At 12-months, intervention participants had significantly greater improvements in weight (-4.5% [95%CI: -6.5, -2.5]; p < 0.001), fat mass (-3.3 kg [-4.8, -1.9]; p < 0.001), metabolic syndrome risk score (-0.19 [-0.32, -0.05]; p = 0.006), waist circumference (-3.2 cm [-5.5, -0.9]; p = 0.007), fasting plasma glucose (-0.23 mmol/L [-0.44, -0.02]; p = 0.032), physical quality of life (2.7 [0.7, 4.6]; p = 0.007; Cohen's effect size (d) = 0.40), musculoskeletal pain (-0.5 [-0.8, -0.2]; p = 0.003; d = 0.49), and body image (-0.2 [-0.4, -0.0]; p = 0.030; d = 0.31) than usual care. At 18 months, effects on weight, adiposity, and metabolic syndrome risk scores were sustained; however, significant reductions in lean mass were observed (-1.1 kg [-1.7, -0.4]; p < 0.001). This intervention led to sustained improvements in adiposity and metabolic syndrome risk.

Metabolic Syndrome in Breast Cancer Patients: An Observational Study

Background:

The reported association between metabolic syndrome (MetS) and breast cancer may have a significant impact on the incidence and mortality related to breast cancer. We undertook this study to find if the disease is different in patients with MetS.

Materials and Methods:

Patients with biopsy-proven breast cancer were divided into groups based on the presence or absence of MetS (according to the IDF definition of 2006) and also based on menopausal status. The presence of known risk and prognostic factors were also recorded, and the groups were compared.

Results:

A total of 305 patients were recruited, of which 191 (62.6%) had MetS. Patients with MetS were older than those without (52.1 versus 48.3 years, P = .014) and had a lower incidence of nulliparity (4.1% vs 12.8%, P = .005) and dense breasts (2.9% in MetS vs 10.8% in no MetS, P = .009). On further dividing into premenopausal and postmenopausal, these differences persisted only in premenopausal patients. MetS group had a lower number of HER2-positive tumours (14.3% for MetS, 23.9% for no MetS; P = .036). After dividing into premenopausal and postmenopausal, significant differences were observed in distant metastases (5.4% in MetS vs 16.1% in no MetS, P = .045) and in grade (higher grade in MetS, P = .05) in premenopausal patients. In postmenopausal patients, difference was observed in HER2 positivity (12.3% in MetS vs 28.8% in no MetS, P = .008).

Conclusions:

Breast cancer in patients with MetS may not be significantly different from breast cancer in patients without MetS.

Population-based recurrence rates among older women with HR-positive, HER2-negative early breast cancer: Clinical risk factors, frailty status, and differences by race

BACKGROUND

Multiple independent risk factors are associated with the prognosis of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) breast cancer (BC), the most common BC subtype. This study describes U.S. population-based recurrence rates among older, resected women with HR+/HER2- early BC.

METHODS

We conducted a retrospective cohort study of older women diagnosed with incident, invasive stages I-III HR+/HER2- BC who underwent surgery to remove the primary tumor using the Surveillance, Epidemiology, and End Results (SEER)-Medicare Linked Database (2007-2015). SEER records and administrative health claims data were used to ascertain patient and tumor-specific characteristics, treatment, and frailty status. Cumulative incidences of BC recurrence were estimated using a validated algorithm for administrative claims data. Multivariable Fine-Gray competing risk models estimated adjusted subdistribution hazards ratios and 95 % confidence intervals for associations with BC recurrence risk.

RESULTS

Overall, 46,027 women age ≥65 years were included in our analysis. Over a median follow up of 7 years, 6531 women experienced BC recurrence with an estimated 3 and 5-year cumulative incidence rates of 10 % and 16 %, respectively. Higher 3- and 5-year cumulative incidences were observed in women with larger tumor size (5+ cm, 21 % and 28 %), lymph node involvement (4+ nodes, 27 % and 37 %), and with frail health status at diagnosis (13 % and 20 %). Independent of these clinical risk factors, Black, Hispanic and American Indian/Alaskan Native women had significantly increased BC recurrence risks.

CONCLUSIONS

Rates of recurrence in HR+/HER2- early BC differs by several patient and clinical factors, including high-risk tumor characteristics. Racial differences in BC outcomes deserve continued attention from clinicians and policymakers.

Analysis of research on metabolic syndrome in cancer survivors using topic modeling and social network analysis

This study aimed to identify the relationships between the keywords of research on metabolic syndrome in cancer survivors and the entire knowledge research structure, through topic extraction from a macro perspective. From six electronic databases, 918 studies published between 1996 and 2019 were identified and reviewed, and 365 were included. Keyword network analysis and topic modeling were applied to examine the studies. In keyword network analysis, "obesity," "treatment," "breast cancer," "body mass index," and "prostate cancer" were the major keywords, whereas "obesity" and "breast" were the dominant keywords and ranked high in frequency, degree centrality, and betweenness centrality. In topic modeling, five clustered topics emerged, namely metabolic syndrome component, post CTX(chemotherapy) sequence, prostate-specific antigen-sensitive plot, lifestyle formation, and insulin fluctuation. Topic 2, post CTX sequence, showed the highest salience in earlier studies, but this has decreased over time, and the themes of the studies have also broadened. This study may provide critical basic data for determining the changing trends of research on metabolic syndrome in cancer survivors and for predicting the direction of future research through the visualization of the effects and interactions between the major keywords in research on metabolic syndrome in cancer survivors.

Outcomes between intensity-modulated radiation therapy versus 3D-conformal in early stage glottic cancer

BACKGROUND

The purpose of this study is to evaluate practice patterns and outcomes between intensity-modulated radiation therapy (IMRT) and 3D-conformal radiation (3D-CRT) in early stage glottic cancer.

METHODS

The linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database was used to identify and compare patient and disease profiles, mortality, and toxicity in patients with T1-2 larynx cancer undergoing definitive radiation (RT).

RESULTS

A total of 1520 patients underwent definitive radiation with 3D-CRT (n = 1309) or IMRT (n = 211). Non-white race, those with a Charlson Comorbidity Index ≥2, T2 disease, and those treated at community practices were more likely to undergo IMRT. Rates of IMRT increased from 2006 to 2015, while relative rates of 3D-CRT decreased. Two-year CSS was superior with 3D-CRT (hazard ratio [HR], 0.38; 95% confidence interval [CI], 0.22-0.65; p < 0.001). There was no difference in OS between 3D-CRT and IMRT (p = 0.119).

CONCLUSIONS

Patients receiving 3D-CRT had improved CSS compared to IMRT with no difference in OS.

Association Between Metabolic Syndrome and Immunohistochemical Profile at Breast Cancer Diagnosis in Postmenopausal Women

BACKGROUND

The aim of this study was to evaluate the association between metabolic syndrome (MetS) and the immunohistochemical profile of breast cancer (BC) in postmenopausal women.

METHODS

This cross-sectional cohort study included 189 women, aged 45 to 75years and amenorrhea >12 months, with newly diagnosed BC and no previous cancer treatment. Clinical, anthropometric and biochemical data were collected, as well as data on BC hormone status (estrogen receptor, ER; progesterone receptor, PR; human epidermal growth factor receptor-2, HER-2), and epithelial proliferative activity (Ki-67). Tumors were divided into 5 subtypes:luminal A, luminal B HER-2 negative, luminal B HER-2 positive, non-luminal HER-2, and triple negative. Women with three or more of the following criteria were diagnosed with MetS: waist circumference ≥88cm; triglycerides ≥150mg/dL; HDL-cholesterol <50mg/dL; blood pressure ≥130/85mmHg; glucose ≥100mg/dL.

RESULTS

Sixty-three (33.3%) of the 189 patients had MetS at the time of diagnosis. Women with MetS had a higher frequency of tumors ≤ 2cm than women without MetS (49.2% vs. 31.8%) (P = .038). There were no differences in histological grade, staging, or axillary lymph node metastasis (P > .05). The proportion of PR-positive (P = .006), HER-2-negative (P = .034), and luminal B HER-2-negative (P = .038) tumors was higher among patients with MetS compared to women without MetS (79.4% vs. 61.8%, 89.9% vs. 78.6% and 44.5% vs. 27.8%, respectively). Multivariate analysis adjusted for age, time since menopause and BMI showed a higher risk for luminal B HER-2-negative tumors among women with MetS (OR 2.00, 95% CI 1.03-3.89), obese patients (OR 2.03, 95% CI 1.06-3.90), and women with abdominal obesity (OR 1.96, 95% CI 1.01-4.03).

CONCLUSION

In postmenopausal women with newly diagnosed BC, the presence of MetS was associated with smaller tumor size, PR-positive and HER-2-negative status, and the luminal B tumor subtype.

Metabolic comorbidities and the association with risks of recurrent metastatic disease in breast cancer survivors

BACKGROUND

Obesity and other metabolic comorbidities affect over 10% of patients with breast cancer and are closely related with adverse outcomes. Although metabolic comorbidities among breast cancer patients in low- and middle-income countries are suggested to be lower, only a few studies are currently available. Effective management of metabolic comorbidities in cancer patients has been associated with better outcomes.

METHODS

Non-metastatic breast cancer patients (N = 1081) treated in our department (2014-2018) were monitored for the presence of high Body Mass Index (BMI), diabetes or glucose intolerance, dyslipidemia, and hypertension and the development of recurrent metastatic diseases during a median follow-up of 3.9 years.

RESULTS

Glucose intolerance, hypertension, dyslipidemia, and BMI ≥ 27.7 kg/m² considered at risk for metabolic comorbidities were found in 26.5, 42.6, 27.7, and 23.3% of breast cancer patients, respectively. Diabetes or glucose intolerance and having both glucose intolerance and dyslipidemia were associated with the risk of recurrent metastatic disease (OR = 1.442, 95%CI = 1.071-1.943, p = 0.016 and OR = 1.495, 95%CI = 1.090-2.049, p = 0.010; respectively). Having three or more metabolic comorbidities was significantly associated with the risk of recurrent metastatic disease (OR = 1.647, 95%CI = 1.139-2.382, p = 0.008) compared to patients without any comorbidity. The metabolic comorbidities were distributed unevenly among breast cancer subtypes. A significant association with recurrent metastatic disease was found in the Luminal B-like subtype. In post-menopausal patients, having more than three comorbidities was associated with a higher risk of recurrent metastatic disease compared to those without any comorbidity (OR = 2.000, 95%CI = 1.035-3.067, p = 0.001). The risks of having three or more metabolic comorbidities were significantly higher in breast cancer survivors who were obese, lived in an urban area, and received hormonal therapy of aromatase inhibitors.

CONCLUSION

Metabolic comorbidities were frequently found in breast cancer patients and were associated with higher risks to develop recurrent metastatic disease, particularly in post-menopausal women. Subsequent larger studies are needed to better understand the association of metabolic comorbidities with patients' quality of life and prognosis, and to explore the potential combination of clinical intervention and lifestyle modification in breast cancer survivors to treat as well as reduce their impact.

Impact of cholesterol-pathways on breast cancer development, a metabolic landscape

ApoB-lipoproteins and their components modulate intracellular metabolism and have been associated with the development of neoplastic phenomena, such as proliferation, anchorage-independent growth, epithelial-mesenchymal transition, and cancer invasion. In cancer cells, the modulation of targets that regulate cholesterol metabolism, such as synthesis de novo, endocytosis, and oxidation, are contributing factors to cancer development. While mechanisms associated with sterol regulatory element-binding protein 2 (SREBP-2)/mevalonate, the low-density lipoprotein receptor (LDL-R) and liver X receptor (LXR) have been linked with tumor growth; metabolites derived from cholesterol-oxidation, such as oxysterols and epoxy-cholesterols, also have been described as tumor processes-inducers. From this notion, we perform an analysis of the role of lipoproteins, their association with intracellular cholesterol metabolism, and the impact of these conditions on breast cancer development, mechanisms that can be shared during atherogenesis promoted mainly by LDL. Pathways connecting plasma dyslipidemias in conjunction with the effect of cholesterol-derived metabolites on intracellular mechanisms and cellular plasticity phenomena could provide new approaches to elucidate the triggering factors of carcinogenesis, conditions that could be considered in the development of new therapeutic approaches.

Metabolic syndrome risk components and mortality after triple-negative breast cancer diagnosis in postmenopausal women in the Women's Health Initiative

BACKGROUND

Triple-negative breast cancer (TNBC) has a high recurrence risk and poor clinical outcomes. Associations between metabolic syndrome (MetS) risk components and mortality in postmenopausal women with TNBC were examined in the Women's Health Initiative.

METHODS

Five hundred forty-four postmenopausal women were diagnosed with nonmetastatic TNBC. Baseline risk components included a high waist circumference (≥88 cm), high blood pressure, hypercholesterolemia, and diabetes. Groups were categorized by the number of MetS risk components: none, 1 or 2, or 3 or 4. Hazard ratios (HRs) and 95% confidence intervals (CIs) across groups were computed with multivariable adjusted Cox models. Outcomes included breast cancer-specific mortality and breast cancer overall mortality (breast cancer followed by death from any cause). Variables in the multivariable model included age at TNBC diagnosis; race/ethnicity; income; education; clinical/observational trial status; history of oral contraceptive, hormone, and/or statin use; cancer stage; and chemotherapy and/or radiation treatment status.

RESULTS

Of the 544 participants with TNBC, 33% had no MetS risk components (n = 178), 59% had 1 or 2 risk components (n = 323), and 8% had 3 or 4 risk components (n = 43). After a median follow-up from diagnosis of 8.3 years, multivariable results showed that women with 3 or 4 risk components had a nonsignificantly higher risk of breast cancer mortality (HR, 2.05; 95% CI, 0.94-4.47 trend P = .114) and a significantly higher risk of overall mortality (HR, 2.13; 95% CI, 1.22-3.71; trend P = .006) versus women with 0 risk components.

CONCLUSIONS

Postmenopausal women with TNBC and 3 or 4 MetS risk components have a nonsignificantly higher breast cancer mortality risk and a significantly higher overall mortality risk, likely because of negative influences of metabolic risk factors on several causes of death.

Breast cancer and the renin-angiotensin system (RAS): Therapeutic approaches and related metabolic diseases

The Renin-Angiotensin System (RAS) is classically recognized for regulating blood pressure and fluid balance. Recently, this role has extended to other areas including inflammation, obesity, diabetes, as well as breast cancer. RAS components are expressed in normal and cancerous breast tissues, and downregulation of RAS inhibits metastasis, proliferation, angiogenesis, and desmoplasia in the tumor microenvironment. Therefore, RAS inhibitors (Angiotensin receptor blockers, ARBs, or angiotensin converting enzyme inhibitors, ACE-I) may be beneficial as preventive adjuvant therapies to thwart breast cancer development and improve outcomes, respectively. Given the beneficial effects of RAS inhibitors in metabolic diseases, which often co-exist in breast cancer patients, combining RAS inhibitors with other breast cancer therapies may enhance the effectiveness of current treatments. This review scrutinizes above associations, to advance our understanding of the role of RAS in breast cancer and its potential for repurposing of RAS inhibitors to improve the therapeutic approach for breast cancer patients.

Exercise-A Panacea of Metabolic Dysregulation in Cancer: Physiological and Molecular Insights

Metabolic dysfunction is a comorbidity of many types of cancers. Disruption of glucose metabolism is of concern, as it is associated with higher cancer recurrence rates and reduced survival. Current evidence suggests many health benefits from exercise during and after cancer treatment, yet only a limited number of studies have addressed the effect of exercise on cancer-associated disruption of metabolism. In this review, we draw on studies in cells, rodents, and humans to describe the metabolic dysfunctions observed in cancer and the tissues involved. We discuss how the known effects of acute exercise and exercise training observed in healthy subjects could have a positive outcome on mechanisms in people with cancer, namely: insulin resistance, hyperlipidemia, mitochondrial dysfunction, inflammation, and cachexia. Finally, we compile the current limited knowledge of how exercise corrects metabolic control in cancer and identify unanswered questions for future research.

Cardiometabolic risk factors and survival after cancer in the Women's Health Initiative

BACKGROUND

Cardiometabolic abnormalities are a leading cause of death among women, including women with cancer.

METHODS

This study examined the association between prediagnosis cardiovascular health and total and cause-specific mortality among 12,076 postmenopausal women who developed local- or regional-stage invasive cancer in the Women's Health Initiative (WHI). Cardiovascular risk factors included waist circumference, hypertension, high cholesterol, and type 2 diabetes. Obesity-related cancers included breast cancer, colorectal cancer, endometrial cancer, kidney cancer, pancreatic cancer, ovarian cancer, stomach cancer, liver cancer, and non-Hodgkin lymphoma. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) adjusted for important predictors of survival.

RESULTS

After a median follow-up of 10.0 years from the date of the cancer diagnosis, there were 3607 total deaths, with 1546 (43%) due to cancer. Most participants (62.9%) had 1 or 2 cardiometabolic risk factors, and 8.1% had 3 or 4. In adjusted models, women with 3 to 4 risk factors (vs none) had a higher risk of all-cause mortality (HR, 1.99; 95% CI, 1.73-2.30), death due to cardiovascular disease (CVD) (HR, 4.01; 95% CI, 2.88-5.57), cancer-specific mortality (HR, 1.37; 95% CI, 1.1-1.72), and other-cause mortality (HR, 2.14; 95% CI, 1.70-2.69). A higher waist circumference was associated with greater all-cause mortality (HR, 1.17; 95% CI, 1.06-1.30) and cancer-specific mortality (HR, 1.22; 95% CI, 1.04-1.42).

CONCLUSIONS

Among postmenopausal women diagnosed with cancer in the WHI, cardiometabolic risk factors before the cancer diagnosis were associated with greater all-cause, CVD, cancer-specific, and other-cause mortality. These results raise hypotheses regarding potential clinical intervention strategies targeting cardiometabolic abnormalities that require future prospective studies for confirmation.

LAY SUMMARY

This study uses information from the Women's Health Initiative (WHI) to find out whether cardiac risk factors are related to a greater risk of dying among older women with cancer. The WHI is the largest study of medical problems faced by older women in this country. The results show that women who have 3 or 4 risk factors are more likely to die of any cause, heart disease, or cancer in comparison with women with no risk factors. It is concluded that interventions to help to lower the burden of cardiac risk factors can have an important impact on survivorship among women with cancer.

Prevalence of metabolic syndrome among breast cancer survivors in East Coast of Peninsular Malaysia

Background

To date, limited data are available on metabolic syndrome prevalence among breast cancer survivors in Malaysia. Therefore, this study was conducted to determine the prevalence of metabolic syndrome and abnormal metabolic syndrome components among breast cancer survivors in East Coast of Peninsular Malaysia.

Methods

This cross-sectional study included 95 breast cancer survivors (age 53.7 ± 7.6 years) who have completed main cancer treatments for ≥6 months. Cancer survivors were recruited from two main government hospitals in Kelantan and Terengganu using a purposive sampling method.

Results

According to the Harmonized criteria, the metabolic syndrome prevalence was 50.5%. Among those with metabolic syndrome, the most prevalent abnormal metabolic components were triglycerides (91.2%), fasting blood glucose (79.6%) and HDL-c level (78.4%). Except for total cholesterol and LDL-c, all other metabolic syndrome components were significantly different (p < 0.05) between those with and without metabolic syndrome. Significant differences between metabolic syndrome and non-metabolic syndrome groups were found for weight, BMI, waist circumference, body fat percentage and cancer stages (p < 0.05). However, no significant relationship was reported between sociodemographic, clinical parameters and metabolic syndrome among breast cancer survivors in this study.

Conclusions

Metabolic syndrome was highly prevalent among breast cancer survivors. It is recommended for health care professionals to closely monitor and improve the triglycerides, blood glucose and HDL-c level of the breast cancer survivors under their care to control the detrimental effect of metabolic syndrome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10288-9.

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

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

Construction of a Prognostic Risk Prediction Model for Obesity Combined With Breast Cancer

The improvement in the quality of life is accompanied by an accelerated pace of living and increased work-related pressures. Recent decades has seen an increase in the proportion of obese patients, as well as an increase in the prevalence of breast cancer. More and more evidences prove that obesity may be one of a prognostic impact factor in patients with breast cancer. Obesity presents unique diagnostic and therapeutic challenges in the population of breast cancer patients. Therefore, it is essential to have a better understanding of the relationship between obesity and breast cancer. This study aims to construct a prognostic risk prediction model combining obesity and breast cancer. In this study, we obtained a breast cancer sample dataset from the GEO database containing obesity data [determined by the body mass index (BMI)]. A total of 1174 genes that were differentially expressed between breast cancer samples of patients with and without obesity were screened by the rank-sum test. After weighted gene co-expression network analysis (WGCNA), 791 related genes were further screened. Relying on single-factor COX regression analysis to screen the candidate genes to 30, these 30 genes and another set of TCGA data were intersected to obtain 24 common genes. Finally, lasso regression analysis was performed on 24 genes, and a breast cancer prognostic risk prediction model containing 6 related genes was obtained. The model was also found to be related to the infiltration of immune cells. This study provides a new and accurate prognostic model for predicting the survival of breast cancer patients with obesity.

Factors Affecting Onset and Persistence of Metabolic Syndrome in Korean Breast Cancer Survivors: A Prospective Study

This study aimed to investigate the onset and persistence of metabolic syndrome in breast cancer survivors in a community setting. The study included 329 female breast cancer survivors from 39 community health examination centers located in 14 urban areas in Korea. After an average of 4.6 years of follow-up, based on the presence of metabolic syndrome at baseline and follow-up, the subjects were assigned to three groups: Non-metabolic syndrome (n = 249), onset (n = 32), and persistent (n = 48). Factors associated with the metabolic syndrome were analyzed and presented as odds ratios (ORs). Older age, postmenopausal status, lower education, and lower-income level were associated with an increased prevalence of metabolic syndrome in the onset Mets and persistent Mets group. In particular, when the breast cancer survivor was obese (≥25 kg/m²), the probability of developing metabolic syndrome was 3.33 times higher than normal-weight subjects (<23 kg/m²) and the probability of metabolic syndrome persisting was 16.34 times. When breast cancer survivors were in their 60s or older, the probability of metabolic syndrome persisting was 4.27 times higher than those in their 40s. To prevent the onset and persistence of metabolic syndrome in breast cancer survivors, health-care providers should identify risk factors. Obesity, in particular, should be controlled.

Frailty and aging in cancer survivors

There are over 15 million survivors of cancer in the United States whose rates of frailty, an aging phenotype, range from just under 10% to over 80%. Frailty impacts not only disease survival but also long-term function and quality of life in children, adolescents, and in all adults diagnosed and/or treated for cancer. This review explains frailty as a construct and model of physiologic well-being. It also describes how frailty at diagnosis impacts cancer outcomes in adult populations and enumerates the prevalence of frailty in different populations of cancer survivors. Biological mechanisms responsible for aging and potentially for frailty among individuals with or who have been treated for cancer are discussed. Finally, promising pharmaceutical and lifestyle interventions designed to impact aging rather than a specific disease, tested in other populations, but likely applicable in cancer patients and survivors, are discussed.

Metabolic syndrome and early stage breast cancer outcome: results from a prospective observational study

PURPOSE

Obesity and insulin resistance have been associated with poor prognosis in breast cancer (BC). The present prospective study aimed to investigate the impact of metabolic syndrome (MetS) and its components on early BC (eBC) patients' outcome.

METHODS

MetS was defined by the presence of 3 to 5 of the following components: waist circumference > 88 cm, blood pressure ≥ 130/≥ 85 mmHg, serum levels of triglycerides ≥ 150 mg/dL, high density lipoprotein < 50 mg/dL and fasting glucose ≥ 110 mg/dL. Seven hundred and seventeen patients with data on ≥ 4 MetS components at BC diagnosis were enrolled. Study population was divided into two groups: patients with < 3 (non-MetS) vs. ≥ 3 components (MetS). Categorical variables were analyzed by Chi-square test and survival data by log-rank test and Cox proportional hazards regression model.

RESULTS

Overall, 544 (75.9%) and 173 (24.1%) women were categorized as non-MetS and MetS, respectively. MetS patients were more likely to be older, postmenopausal, and insulin-resistant compared to non-MetS patients (p < 0.05). In multivariate analysis, MetS patients had a numerically higher risk of relapse [disease-free survival (DFS), hazard ratio (HR) 1.51, p = 0.07] and a significantly higher risk of death compared to non-MetS patients [overall survival (OS), HR 3.01, p < 0.0001; breast cancer-specific survival (BCSS), HR 3.16, p = 0.001]. Additionally, patients with 1 to 2 components of MetS had an increased risk of dying compared to patients with 0 components (OS, HR 4.90, p = 0.01; BCSS, HR 6.07, p = 0.02).

CONCLUSIONS

MetS correlated with poor outcome in eBC patients. Among patients without full criteria for MetS diagnosis, the presence of 1 or 2 components of the syndrome may predict for worse survival.

IGF-1 Interacted With Obesity in Prognosis Prediction in HER2-Positive Breast Cancer Patients

Purpose: Dysmetabolism and high circulating insulin-like growth factor 1 (IGF-1) would increase breast cancer risk, but its association with survival in HER2+ breast cancer patients has not been well-studied. Herein, we aim to evaluate the prognostic value of IGF-1 and metabolic abnormalities in HER2+ population.

Patients and Methods: HER2+ breast cancer patients treated in Ruijin Hospital between November 2012 and June 2017 were retrospectively analyzed. Median value of circulating IGF-1 was adopted to classify low or high IGF-1 group. Metabolic syndrome (MetS) was defined using AHA/NHLBI criteria. Overweight was defined by body mass index (BMI) ≥ 24.0 kg/m² in Chinese population.

Results: Overall, 679 patients were included and 209 had synchronous MetS. High IGF-1 level was more common in pre/peri-menopausal women (P < 0.001) and high IGFBP-3 patients (P < 0.001). After a median follow-up of 36 months, 52 patients had disease recurrences. IGF-1 level was not associated with recurrence-free survival (RFS, P = 0.620) in the whole population. However, exploratory subgroup analysis found that BMI and IGF-1 interacted in predicting RFS (P = 0.009). For non-overweight patients, high IGF-1 showed a superior 4-years RFS (91.1 vs. 85.0%; HR 0.53, 95% CI 0.27–1.00, P = 0.049) compared with patients with low IGF-1 level. In contrast, for overweight patients, high IGF-1 was associated with an impaired 4-years RFS (88.3 vs. 95.7%, HR 3.20, 95% CI 1.00–10.21, P = 0.038). Furthermore, high IGF-1 level was independently associated with better OS in the whole (HR 0.26, 95% CI 0.08–0.82, P = 0.044) as well as non-overweight population (HR 0.15, 95% CI 0.03–0.68, P = 0.005).

Conclusions: IGF-1 level was not associated with RFS in HER2+ breast cancer patients. However, IGF-1 and BMI had significant interaction in disease outcome prediction in HER2+ patients. High IGF-1 was protective in non-overweight patients, but risk factor for those overweight, which deserves further evaluation.

Association between metabolic syndrome and prognosis of breast cancer: a meta-analysis of follow-up studies

BACKGROUND

Metabolic syndrome (MetS) has been suggested to be a risk factor for many cancers, including breast cancer. However, it remains unclear whether MetS predicts poor prognosis in women with breast cancer. A meta-analysis was performed to summarize the association between MetS and clinical outcome in women with breast cancer.

METHODS

Cohort studies were identified by search of PubMed and Embase databases. A random-effect model incorporating the potential heterogeneity was applied to pool the results. Subgroup analyses according to the ethnicity and study design were performed.

RESULTS

Nine cohort studies with 17,892 women with breast cancer were included. Pooled results showed that MetS was significantly associated with an increased risk of breast cancer recurrence (adjusted risk ratio [RR] = 1.52, 95%, p = 0.02). Subgroup analyses showed that MetS was independently associated with increased recurrence of breast cancer in Caucasians (adjusted RR = 1.75, p = 0.02), but not in Asians (adjusted RR = 1.07, p = 0.81), and MetS was associated with a trend of increased risk of breast cancer recurrence in both the prospective and retrospective studies. Although we failed to show a significant association between MetS and breast cancer related deaths (adjusted RR = 1.24, p = 0.41), MetS was associated with increased risk of all-cause deaths in these patients (adjusted RR = 1.80, p < 0.001).

CONCLUSIONS

MetS may predict the risk of cancer recurrence and mortality in women with breast cancer, particularly in Caucasians.

Metabolic Syndrome, Exercise, and Cardiovascular Fitness in Breast Cancer Survivors

Comorbid illness contributes to poorer cancer outcomes and higher mortality. Metabolic syndrome (MetS) includes a cluster of risk factors that are associated with an increased risk of comorbidities. Routine physical activity represents a risk reduction strategy for cancer survivors. From 148 participants in a 12-month randomized control trial (RCT) of a fitness center exercise intervention compared to home physical activity group, a subset analysis was conducted to explore the effect of exercise on MetS risk factors. There were 32 (21.6%) breast cancer survivors who met the criteria for MetS at baseline. Over the 12 months, there were significantly fewer participants who met the criteria for MetS (p < .01), and there was significant improvement in individual risk factors, specifically fasting blood sugar (p = .01), and high-density lipoprotein (HDL; p = .02). Cardiovascular fitness was evaluated and greater heart recovery rate (HRR) was negatively associated with waist circumference, triglycerides, systolic blood pressure, fasting blood sugar, and MetS risk (p < .02) and positively associated with HDL (p = .03). Oncology advanced practitioners are uniquely qualified to integrate risk reduction into the management of at-risk oncology patients.

Metabolic Syndrome, and Particularly the Hypertriglyceridemic-Waist Phenotype, Increases Breast Cancer Risk, and Adiponectin Is a Potential Mechanism: A Case-Control Study in Chinese Women

Objective: To investigate the association between metabolic syndrome and breast cancer and to elucidate the potential mechanism underlying this association. Patients and Methods: Based on baseline data drawn from 21 hospitals in 11 provinces of China, we performed a case-control study among 1,127 women (595 cases and 532 controls), divided into premenopausal, and postmenopausal subgroups. Student's t test, Pearson's χ² test, and logistic regression analyses were performed to ascertain the association between breast cancer and metabolic syndrome, including all of its components. In addition, we attempted to clarify the potential role of adiponectin in this association. Results: Among the components of metabolic syndrome, abnormal waist circumference was the component that markedly increased breast cancer risk in premenopausal women (OR 1.447, 95% CI 1.043-2.006). Metabolic syndrome with clusters of special risk factors showed an association with breast cancer risk. Among all these components of metabolic syndrome, the hypertriglyceridemic-waist (HW) phenotype significantly increased breast cancer risk (OR 1.56, 95% CI 1.02-2.39), regardless of menopausal status, rendering it a strong predictor of breast cancer. Total adiponectin levels and high-molecular-weight adiponectin were reversely associated with metabolic syndrome. In addition, total adiponectin levels among breast cancer patients were much lower than among controls (6.67 ± 3.05 vs. 8.01 ± 4.18, p = 0.014) only in the HW phenotype subgroup. Furthermore, the HW phenotype was associated with increased risk of estrogen receptor/progesterone receptor-positive (ER+/PR+) and -negative (ER-/PR-) breast cancer, with a 51% (OR 1.51, 95% CI 1.03-2.21) and 69% (OR 1.69, 95% CI 1.05-2.72) increase, respectively. However, there was no significant association between the HW phenotype and the ER+/PR- subtype. These results suggested that low adiponectin levels may be a mechanism that explains the association between the HW phenotype and breast cancer risk. Conclusion: Metabolic syndrome with special cluster factors is related to breast cancer risk; in particular, the HW phenotype can be regarded as a strong predictor of breast cancer. As an important factor involved in fat metabolism, adiponectin may strongly predict metabolic syndrome, especially the HW phenotype and breast cancer. Further research into this mechanism and epidemiological studies are needed. This study provides new evidence for the role of a healthy lifestyle in preventing breast cancer.

Risk factors for metachronous contralateral breast cancer: A systematic review and meta-analysis

BACKGROUND

The risk of developing metachronous contralateral breast cancer (CBC) is a recurrent topic at the outpatient clinic. We aimed to provide CBC risk estimates of published patient, pathological, and primary breast cancer (PBC) treatment-related factors.

METHODS

PubMed was searched for publications on factors associated with CBC risk. Meta-analyses were performed with grouping of studies by mutation status (i.e., BRCA1, BRCA2, CHEK2 c.1100delC), familial cohorts, and general population-based cohorts.

RESULTS

Sixty-eight papers satisfied our inclusion criteria. Strong associations with CBC were found for carrying a BRCA1 (RR = 3.7; 95%CI:2.8-4.9), BRCA2 (RR = 2.8; 95%CI:1.8-4.3) or CHEK2 c.1100delC (RR = 2.7; 95%CI:2.0-3.7) mutation. In population-based cohorts, PBC family history (RR = 1.8; 95%CI:1.2-2.6), body mass index (BMI) ≥30 kg/m² (RR = 1.5; 95%CI:1.3-1.9), lobular PBC (RR = 1.4; 95%CI:1.1-1.8), estrogen receptor-negative PBC (RR = 1.5; 95%CI:1.0-2.3) and treatment with radiotherapy <40 years (RR = 1.4; 95%CI:1.1-1.7) was associated with increased CBC risk. Older age at PBC diagnosis (RR per decade = 0.93; 95%CI:0.88-0.98), and treatment with chemotherapy (RR = 0.7; 95%CI:0.6-0.8) or endocrine therapy (RR = 0.6; 95%CI:0.5-0.7) were associated with decreased CBC risk.

CONCLUSIONS

Mutation status, family history, and PBC treatment are key factors for CBC risk. Age at PBC diagnosis, BMI, lobular histology and hormone receptor status have weaker associations and should be considered in combination with key factors to accurately predict CBC risk.

Metabolic syndrome and risk of breast cancer mortality by menopause, obesity, and subtype

PURPOSE

To investigate the association between metabolic syndrome (MetS) and risk of breast cancer mortality by menopausal status, obesity, and subtype.

METHODS

Data from 94,555 women free of cancer at baseline in the National Institute of Health-American Association of Retired Persons Diet and Health Study cohort (NIH-AARP) were used to investigate the prospective associations of baseline MetS and components with risk of breast cancer mortality using Cox proportional hazard regression models adjusted for baseline behavioral and demographic covariates.

RESULTS

During a mean follow-up duration of 14 years, 607 women in the cohort died of breast cancer. Overall, MetS was associated with a 73% increased risk of breast cancer mortality (HR 1.73; 95% CI 1.09-2.75); the association remained significant among post-menopausal women overall (HR 2.07, 95% CI 1.32, 3.25), and among those with overweight/obesity (HR 1.15, 95% CI 0.81, 1.64). MetS was associated with increased risk of breast cancer mortality for ER+/PR+ (HR 1.28, 95% CI 0.52, 3.16) and lower risk for ER-/PR- (HR 0.44, 95% CI 0.11, 1.75) subtypes; however, the associations were not statistically significant. Of the individual MetS components, high waist circumference (HR 1.32, 95% CI 1.03, 1.70), high cholesterol (HR 1.24, 95% CI 1.05, 1.46), and hypertension (HR 1.24, 95% CI 1.05, 1.46) were independently associated with increased risk of breast cancer mortality.

CONCLUSIONS

MetS was associated with increased risk of breast cancer mortality, especially among post-menopausal women. Further studies with larger sample sizes are needed to definitively determine the extent to which these associations vary by breast cancer subtype.

Metabolic Syndrome and the Risk of Breast Cancer and Subtypes by Race, Menopause and BMI

The objective of this study was to investigate the association of metabolic syndrome (MetS) with the risk of invasive breast cancer and molecular subtypes across race, menopause, and body mass index (BMI) groups. We examined the association of metabolic syndrome and its components with risk of invasive breast cancer among 94,555 female participants of the National Institute of Health-American Association of Retired Persons (NIH-AARP) Diet and Health Study, accounting for ductal carcinoma in situ as a competing risk. Cox proportional hazard regression with the Fine and Gray method was used to generate hazard ratios (HR) and 95% confidence intervals (CI) adjusting for baseline sociodemographic, behavioral, and clinical covariates. During a mean follow-up of 14 years, 5380 (5.7%) women developed breast cancer. Overall, MetS at baseline was associated with a 13% increased risk of breast cancer compared to women without MetS (HR: 1.13, 95% CI: 1.00, 1.27); similar estimates were obtained among postmenopausal women (HR: 1.14, 95% CI: 1.01, 1.29). MetS was associated with a slight but non-significantly increased risk of breast cancer among those with both normal weight and overweight/obesity, and those with estrogen receptor positive breast cancer subtype. In the NIH-AARP cohort, MetS was associated with an increased risk of breast cancer. Further studies are needed to definitively evaluate the association of MetS with triple negative breast cancer subtypes across all levels of BMI.

Associations of metabolic syndrome and C-reactive protein with mortality from total cancer, obesity-linked cancers and breast cancer among women in NHANES III

Although metabolic syndrome (MetS) is a prognostic factor for cancer occurrence, the association of MetS and cancer mortality remains unclear. The purpose of this study was to evaluate whether MetS, components of MetS and C-reactive protein (CRP) are associated with cancer mortality in women. A total of 400 cancer deaths, with 140 deaths from obesity-linked-cancers (OLCas), [breast (BCa), colorectal, pancreatic and endometrial], linked through the National Death Index, were identified from 10,104 eligible subjects aged ≥18 years. Cox proportional hazards regression was used to estimate multivariable-adjusted hazard ratios (HR) for cancer mortality. MetS was associated with increased deaths for total cancer [HR = 1.33, 95% confidence interval (CI) 1.04-1.70] and BCa [HR = 2.1, 95% CI, 1.09-4.11]. The risk of total cancer [HR = 1.7, 95% CI, 1.12-2.68], OLCas [HR = 2.1, 95% CI, 1.00-4.37] and BCa [HR = 3.8, 95% CI, 1.34-10.91] mortality was highest for women with all MetS components abnormal, compared to those without MetS. Linear associations of blood-pressure [HR = 2.5, 1.02-6.12, Quartile (Q) 4 vs Q1, p trend = 0.004] and blood-glucose [HR = 2.2, 1.04-4.60, Q4 vs. Q1, p trend = 0.04] with total-OLCas mortality were observed. A threefold increased risk of BCa mortality was observed for women with enlarged waist circumference, ≥100.9 cm, [HR = 3.5, 1.14-10.51, p trend = 0.008] and in those with increased blood glucose, ≥101 mg/dL, [HR = 3.2, 1.11-9.20, p trend = 0.03] compared to those in Q1. None of the components of MetS were associated with total-cancer mortality. CRP was not associated with cancer mortality. In conclusion, MetS is associated with total-cancer and breast-cancer mortality, with waist circumference, blood pressure and blood glucose as independent predictors of OLCas and BCa mortality.

Impact of pre-diagnostic triglycerides and HDL-cholesterol on breast cancer recurrence and survival by breast cancer subtypes

BACKGROUND

High triglycerides and low levels of high density lipoprotein (HDL)-cholesterol are observed to promote tumor growth. However, whether breast cancer heterogeneity may explain the contradictory influence of triglycerides and cholesterol observed on breast cancer prognosis remains unclear.

METHODS

A population-based survival study among 464 breast cancer cases identified within the Tromsø study was conducted. Pre-diagnostic triglycerides, total-cholesterol and HDL-cholesterol were measured, and detailed clinical and histopathological data were obtained. Using tissue microarray, all breast cancer cases were reclassified into the following subtypes: Luminal A, Luminal B, HER2-enriched, and triple negative breast cancer (TNBC). Multivariable Cox proportional hazards regression models were used to study the associations between pre-diagnostic lipids and breast cancer recurrence, mortality, and survival.

RESULTS

A total of 464 breast cancer patients, with mean age at diagnosis of 57.9 years, were followed for a mean 8.4 years. TNBC patients in the highest tertile of triglycerides (≥ 1.23 mmol/l) had 3 times higher overall mortality compared to TNBC patients in the lowest tertile (≤ 0.82 mmol/l) (HR 2.99, 95% CI 1.17-7.63), and the 5-year overall survival was 19% lower for TNBC patients in the highest vs. lowest tertile of triglycerides (65% vs. 84%). TNBC patients in the highest tertile of the HDL-cholesterol/total-cholesterol ratio (≥0.35), compared to those in the lowest tertile (≤0.27), had a 67% reduced overall mortality risk (HR 0.33, 95% CI 0.12-0.89). No associations were observed between lipids and prognostic outcome among breast cancer patients overall, or among patients with luminal A and luminal B subtypes. Among HER2-enriched patients, pre-diagnostic triglyceride level was inversely associated with overall mortality.

CONCLUSION

Our study suggests that pre-diagnostic triglycerides and the HDL-cholesterol/total-cholesterol ratio may independently provide unique information regarding prognostic outcome among triple negative breast cancer patients. However, a small sample size underlines the need for additional studies.

Changes in metabolic risk, insulin resistance, leptin and adiponectin following a lifestyle intervention in overweight and obese breast cancer survivors

Adiposity and physical activity are modifiable factors that could be important determinants of breast cancer (BC) prognosis through their effects on endogenous reproductive hormones, chronic inflammation and metabolic changes. Therefore, it is necessary to evaluate whether offering lifestyle interventions to BC survivors could affect the levels of certain biomarkers involved in these mechanisms. We designed a pre-post intervention study offering diet and exercise sessions over 12 weeks to 42 overweight/obese BC survivors. Before and after the intervention, we obtained dietary information, anthropometry and cardiorespiratory fitness (CRF) measurements and blood samples to measure metabolic risk, insulin resistance and adipokines biomarkers. Wilcoxon signed-rank tests and Spearman partial correlation coefficients were used to compare pre- and post-measurements and assess the correlations between changes in biomarkers and changes in anthropometry and CRF. Breast cancer survivors showed significant improvements in metabolic risk biomarkers and insulin resistance indicators along with a non-significant leptin decrease and a significant adiponectin decrease. The improvements in metabolic risk biomarkers, insulin resistance indicators and leptin were moderately correlated (0.32 ≤ |r| ≤ 0.55) with the decrease in body mass index and the increase in CRF. Diet and exercise interventions implemented in overweight/obese BC survivors may improve metabolic risk, insulin resistance and leptin biomarkers.

Association of Cardiovascular Risk Factors With Cardiac Events and Survival Outcomes Among Patients With Breast Cancer Enrolled in SWOG Clinical Trials

Background Cardiovascular disease is the primary cause of death among patients with breast cancer. However, the association of cardiovascular-disease risk factors (CVD-RFs) with long-term survival and cardiac events is not well studied. Methods We examined SWOG (formerly the Southwest Oncology Group) breast cancer trials from 1999 to 2011. We identified baseline diabetes, hypertension, hypercholesterolemia, and coronary artery disease by linking trial records to Medicare claims. The primary outcome was overall survival. Patients with both baseline and follow-up claims were examined for cardiac events. Cox regression was used to assess the association between CVD-RFs and outcomes. Results We identified 1,460 participants older than 66 years of age from five trials; 842 were eligible for survival outcomes analysis. At baseline, median age was 70 years, and median follow-up was 6 years. Hypertension (73%) and hypercholesterolemia (57%) were the most prevalent conditions; 87% of patients had one or more CVD-RF. There was no association between any of the individual CVD-RFs and overall survival except for hypercholesterolemia, which was associated with improved overall survival (hazard ratio [HR], 0.73; 95% CI, 0.57 to 0.93; P = .01). With each additional CVD-RF, there was an increased risk of death (HR, 1.23; 95% CI, 1.08 to 1.40; P = .002), worse progression-free survival (HR, 1.12; 95% CI, 1.00 to 1.25; P = .05), and marginally worse cancer-free survival (HR, 1.15; 95% CI, 0.99 to 1.34; P = .07). The relationship between baseline CVD-RFs and cardiac events was analyzed in 736 patients. A strong linear association between the number of CVD-RFs and cardiac event was observed (HR per CVD-RF, 1.41; 95% CI, 1.17 to 1.69; P < .001). Conclusion Among participants in clinical trials, each additional baseline CVD-RF was associated with an increased risk of cardiac events and death. Efforts to improve control of modifiable CVD-RFs are needed, especially among those with multiple risk factors.

Effects of Aerobic and Resistance Exercise on Metabolic Syndrome, Sarcopenic Obesity, and Circulating Biomarkers in Overweight or Obese Survivors of Breast Cancer: A Randomized Controlled Trial

Purpose Metabolic syndrome is associated with an increased risk of cardiovascular disease, type 2 diabetes, and breast cancer recurrence in survivors of breast cancer. This randomized controlled trial assessed the effects of a 16-week combined aerobic and resistance exercise intervention on metabolic syndrome, sarcopenic obesity, and serum biomarkers among ethnically diverse, sedentary, overweight, or obese survivors of breast cancer. Methods Eligible survivors of breast cancer (N = 100) were randomly assigned to exercise (n = 50) or usual care (n = 50). The exercise group participated in supervised moderate-to-vigorous-65% to 85% of heart rate maximum-aerobic and resistance exercise three times per week for 16 weeks. Metabolic syndrome z-score (primary outcome), sarcopenic obesity, and serum biomarkers were measured at baseline, postintervention (4 months), and 3-month follow-up (exercise only). Results Participants were age 53 ± 10.4 years, 46% were obese, and 74% were ethnic minorities. Adherence to the intervention was 95%, and postintervention assessments were available in 91% of participants. Postintervention metabolic syndrome z-score was significantly improved in exercise versus usual care (between-group difference, -4.4; 95% CI, -5.9 to -2.7; P < .001). Sarcopenic obesity (appendicular skeletal mass index, P = .001; body mass index, P = .001) and circulating biomarkers, including insulin ( P = .002), IGF-1 ( P = .001), leptin ( P = .001), and adiponectin ( P = .001), were significantly improved postintervention compared with usual care. At 3-month follow-up, all metabolic syndrome variables remained significantly improved compared with baseline in the exercise group ( P < .01). Conclusion Combined resistance and aerobic exercise effectively attenuated metabolic syndrome, sarcopenic obesity, and relevant biomarkers in an ethnically diverse sample of sedentary, overweight, or obese survivors of breast cancer. Our findings suggest a targeted exercise prescription for improving metabolic syndrome in survivors of breast cancer and support the incorporation of supervised clinical exercise programs into breast cancer treatment and survivorship care plans.

Cardiometabolic risk factors and survival after breast cancer in the Women's Health Initiative

BACKGROUND

Few studies have examined the relationship between cardiometabolic risk factors linked to metabolic syndrome and mortality among women with breast cancer.

METHODS

We used the Women's Health Initiative to evaluate the relationship between cardiometabolic risk factors, including waist circumference (WC), blood pressure, cholesterol level, and presence of type 2 diabetes, and their relation with death from breast cancer, cardiovascular disease (CVD), and other causes among 8641 women with local or regional stage invasive breast cancer. Cox proportional hazards models were used to estimate hazard ratios, and 95% confidence intervals, adjusted for important predictors of survival.

RESULTS

After a median of 11.3 years, there were 2181 total deaths, 619 (28.4%) of which were due to breast cancer. Most participants (55.7%) had at least 2 cardiometabolic risk factors, and 4.9% had 3 or 4. Having a larger number of risk factors was associated with higher risk of CVD and other-cause mortality (P trend < .001 for both), but not with breast cancer mortality (P trend = .86). Increased WC was associated with a higher risk of CVD (hazard ratio [HR], 1.28; 95% confidence interval [CI], 1.05-1.57) and other-cause mortality (HR, 1.32; 95% CI, 1.16-1.49) and only with a small and nonsignificant higher risk of breast cancer mortality (HR, 1.19; 95% CI, 0.93-1.52). The results did not differ in analyses stratified by race, hormone receptor status, or after an analysis of cases diagnosed within 5 years after baseline.

CONCLUSIONS

Among women with early stage breast cancer, cardiometabolic risk factors are significantly associated with cardiovascular and other-cause mortality, but not breast cancer mortality. Cancer 2018;124:1798-807. © 2018 American Cancer Society.

Clinical study on the prevalence and comparative analysis of metabolic syndrome and its components among Chinese breast cancer women and control population

Metabolic syndrome has been previously identified as a risk factor for breast cancer and is increasingly a public health concern. This study aims to investigate the prevalence of metabolic syndrome and its components among primary breast cancer and control population. The clinical data of metabolic syndrome and its components in the breast cancer (605 cases) and control population (3212 cases), from Breast Cancer Center and Physical Examination Center of Chongqing, China, from July 2015 to February 2017, were collected for comparative analysis. This study was prospectively registered in Chinese Clinical Trial Registry (http://www.chictr.org.cn/, number: ChiCTR-OOB-15007543). The prevalence of metabolic syndrome in breast cancer (32.6%) was obviously higher than that in control population (18.2%) (p<0.001; OR: 2.173, 95%CI: 1.793 to 2.633). With age stratification, the prevalence of metabolic syndrome in breast cancer group aged below 60 years (24.9%, p<0.001; OR: 2.216, 95%CI: 1.744 to 2.816) and equal/above 60 years (58.3%, p<0.001; OR: 2.291, 95%CI: 1.580 to 3.322) were also statistically higher than those (13.0% & 37.9%) in control population, respectively. Breast cancer women were more likely to have preobese (BMI 25.0-29.9) or obesity (BMI ≥30.0), broader waist circumference, lower HDL-C level, higher systolic and/or diastolic blood pressure and higher fasting blood glucose level compared to the control population, corresponding prevalence were 31.7%vs.19.4%, 76.0%vs.29.6%, 37.4%vs.30.4%, 34.2%/27.3%vs.27.6%/14.2% and 25.0%vs.20.1%, respectively (p<0.01). In summary, there is high prevalence of metabolic syndrome and its components in Chinese breast cancer women, and metabolic syndrome is closely related with breast cancer. Therefore, screening and prevention strategy of metabolic syndrome should be carried out in the management of breast cancer.

Metabolic dysregulation and cancer mortality in a national cohort of blacks and whites

Background

We examined the association between metabolic dysregulation and cancer mortality in a prospective cohort of Black and White adults.

Methods

A total of 25,038 Black and White adults were included in the analysis. Metabolic dysregulation was defined in two ways: 1) using the joint harmonized criteria for metabolic syndrome (MetS) and 2) based on factor analysis of 15 variables characterizing metabolic dysregulation. We estimated hazards ratios (HRs) and 95% confidence intervals (CIs) for the association of MetS and metabolic dysregulation with cancer mortality during follow-up using Cox proportional hazards models.

Results

About 46% of Black and 39% of White participants met the criteria for MetS. Overall, participants with MetS (HR: 1.22, 95% CI: 1.03–1.45) were at increased risk of cancer-related death. In race-stratified analysis, Black participants with MetS had significantly increased risk of cancer mortality compared with those without MetS (HR: 1.32, 95% CI: 1.01–1.72), increasing to more than a 2-fold risk of cancer mortality among those with five metabolic syndrome components (HR: 2.35, 95% CI: 1.01–5.51).

Conclusions

There are marked racial differences in the prevalence of metabolic dysregulation defined as MetS based on the harmonized criteria. The strong positive associations between MetS and cancer mortality suggests that efforts to improve cancer outcomes in general, and racial disparities in cancer outcomes specifically, may benefit from prevention and management of MetS and its components.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3807-2) contains supplementary material, which is available to authorized users.

Diabetes Treatments and Risks of Adverse Breast Cancer Outcomes among Early-Stage Breast Cancer Patients: A SEER-Medicare Analysis

The widely prescribed diabetes medicine metformin has been reported to lower the risk of incident breast cancer, but it is unclear whether it affects malignant progression after diagnosis. In this study, we conducted a retrospective cohort study using the linked Surveillance, Epidemiology, and End-Results (SEER)-Medicare database. Women were included in the study if they were aged 66 to 80 years, newly diagnosed with stage I or II breast cancer, and enrolled in Medicare Parts A, B, and D during 2007 to 2011. Information on dispensed diabetes-related medications was obtained from Medicare Part D claims data. Our primary outcomes were second breast cancer events (SBCE), breast cancer recurrence, and breast cancer death. Time-varying Cox proportional hazard models were used to estimate HRs and their 95% confidence intervals (CI). Among 14,766 women included in the study, 791 experienced SBCE, 627 had a recurrence, and 237 died from breast cancer. Use of metformin (n = 2,558) was associated with 28% (95% CI, 0.57-0.92), 31% (95% CI, 0.53-0.90), and 49% (95% CI, 0.33-0.78) lower risks of an SBCE, breast cancer recurrence, and breast cancer death. Use of sulfonylureas or insulin was associated with 1.49- (95% CI, 1.00-2.23) and 2.58-fold (95% CI, 1.72-3.90) higher risks of breast cancer death. Further research may be warranted to determine whether metformin is a preferred treatment for diabetes among breast cancer survivors and whether it benefits breast cancer patients without diabetes. Cancer Res; 77(21); 6033-41. ©2017 AACR.