Diabetes and breast cancer risk: a meta-analysis. Br J Cancer. 2012;107:1608-1617. [PMID: 22996614 PMCID: PMC3493760 DOI: 10.1038/bjc.2012.414]

Gestational diabetes and risk of breast cancer before age 55 years

BACKGROUND

The history of gestational diabetes mellitus (GDM) has been associated with breast cancer risk in some studies, particularly in young women, but results of cohort studies are conflicting.

METHODS

We pooled data from 257 290 young (age <55 years) women from five cohorts. We used multivariable Cox proportional-hazards regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between GDM history and risk of breast cancer, overall and by oestrogen receptor (ER) status, before age 55 years, adjusted for established breast cancer risk factors.

RESULTS

Five percent of women reported a history of GDM and 6842 women reported an incident breast-cancer diagnosis (median follow-up = 16 years; maximum = 24 years). Compared with parous women without GDM, women with a history of GDM were not at increased risk of young-onset breast cancer overall (HR = 0.90; 95% CI: 0.78, 1.03) or by ER status (HR = 0.96; 95% CI: 0.79, 1.16 for ER-positive; HR = 1.07; 95% CI: 0.78, 1.47 for ER-negative). Compared with nulliparous women, parous women with a history of GDM had a lower risk of breast cancer overall (HR = 0.79; 95% CI: 0.68, 0.91) and of ER-positive (HR = 0.82; 95% CI: 0.66, 1.02) but not ER-negative (HR = 1.09; 95% CI: 0.76, 1.54) invasive breast cancer. These results were consistent with the HRs comparing parous women without GDM to nulliparous women.

CONCLUSIONS

Results of this analysis do not support the hypothesis that GDM is a risk factor for breast cancer in young women. Our findings suggest that the well-established protective effect of parity on risk of ER-positive breast cancer persists even for pregnancies complicated by GDM.

Bcl-2 and p53 immunophenotypes in colorectal adenocarcinoma in type 2 diabetes mellitus versus non-diabetic patients

We aimed to investigate immunohistochemical expression of the p53 tumor suppressor protein, and the B-cell lymphoma-2 (Bcl-2) apoptotic protein in colorectal adenocarcinoma patients with or without type 2 diabetes mellitus (T2DM). Tissue sections from 95 paraffin-embedded colorectal adenocarcinomas, originating from 52 T2DM and 43 non-diabetic patients, were immunostained for p53 [Ventana mouse monoclonal primary antibody (mAb) in vitro diagnostic (IVD) anti-p53, clone Bp53-11] and Bcl-2 (Ventana mAb IVD anti-Bcl-2, clone Bcl-2/124). Immunohistochemistry analysis did not find statistically significant differences between the two groups, but analysis on subgroups of patients in terms of presence or absence of obesity identified overexpression of p53 (>70% of cells) in the T2DM obese patients compared to non-diabetics. Overexpression of p53 was present in 80% of tumor cells coming from T2DM obese patients compared to 37.2% of tumor cells coming from non-diabetics obese and non-obese, and in 36.6% of tumor cells coming from non-diabetic non-obese patients (p=0.024). There was a single non-diabetic obese patient with p53 overexpression. Most cancer cells of T2DM obese patients presented more frequently p53 overexpression by comparison with cancer cells of the T2DM non-obese patients (80% vs 40.5%, p=0.028). Bcl-2/p53 co-expression was an infrequent event in T2DM patients' group. The results of this study suggest that patients with colorectal adenocarcinoma that associate T2DM and obesity exhibit higher p53 protein expression in malignant cells. In conclusion, our research highlights that obesity is a potential key factor in the relationship between T2DM and colorectal cancer.

Type 2 Diabetes and all-cause mortality among Spanish women with breast cancer

PURPOSE

To explore the effect of type 2 diabetes mellitus (T2DM) on the risk of death among women with breast cancer (BC).

METHODS

A survival analysis was conducted among a cohort of women diagnosed with BC between 2006 and 2012 in Spain (n = 4,493). Biopsy or surgery confirmed BC cases were identified through the state population-based cancer registry with information on patients' characteristics and vital status. Physician-diagnosed T2DM was confirmed based on primary health care clinical history. Cox regression analyses were used to estimate adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for all-cause death. Analyses were adjusted for age, hospital size, several clinical characteristics (including BC stage and histology, among others) and treatment modalities.

RESULTS

Among the 4,493 BC women, 388 (8.6%) had coexisting T2DM. Overall, 1,299 (28.9%) BC women died during the completion of the follow-up and 785 (17.5%) did so during the first five years after BC diagnosis, resulting in a five-year survival rate of 82.5%. The death rate was higher in women with T2DM (43.8% died during whole period and 26.0% during the first five years) when compared with women without T2DM (27.5% and 16.7%, respectively). Accordingly, all-cause mortality was higher in women with T2DM (aHR: 1.22; 95% CI 1.03-1.44), especially if T2DM was diagnosed before BC (aHR:1.24; 95% CI 1.03-1.50) and in women with BC diagnosed before 50 years (aHR: 2.38; 95% CI 1.04-5.48).

CONCLUSIONS

T2DM was associated with higher all-cause mortality among Spanish women with BC, particularly when the T2DM diagnosis was prior to the BC.

Diabetes and Cancer: Risk, Challenges, Management and Outcomes

BACKGROUND

Diabetes mellitus and cancer are commonly coexisting illnesses, and the global incidence and prevalence of both are rising. Cancer patients with diabetes face unique challenges. This review highlights the relationship between diabetes and cancer and various aspects of the management of diabetes in cancer patients.

METHODS

A literature search using keywords in PubMed was performed. Studies that were published in English prior to July 2021 were assessed and an overview of epidemiology, cancer risk, outcomes, treatment-related hyperglycemia and management of diabetes in cancer patients is provided.

RESULTS

Overall, 8-18% of cancer patients have diabetes as a comorbid medical condition. Diabetes is a risk factor for certain solid malignancies, such as pancreatic, liver, colon, breast, and endometrial cancer. Several novel targeted compounds and immunotherapies can cause hyperglycemia. Nevertheless, most patients undergoing cancer therapy can be managed with an appropriate glucose lowering agent without the need for discontinuation of cancer treatment. Evidence suggests that cancer patients with diabetes have higher cancer-related mortality; therefore, a multidisciplinary approach is important in the management of patients with diabetes and cancer for a better outcome.

CONCLUSIONS

Future studies are required to better understand the underlying mechanism between the risk of cancer and diabetes. Furthermore, high-quality prospective studies evaluating management of diabetes in cancer patients using innovative tools are needed. A patient-centered approach is important in cancer patients with diabetes to avoid adverse outcomes.

Obesity, Diabetes, and Increased Cancer Progression

Rates of obesity and diabetes have increased significantly over the past decades and the prevalence is expected to continue to rise further in the coming years. Many observations suggest that obesity and diabetes are associated with an increased risk of developing several types of cancers, including liver, pancreatic, endometrial, colorectal, and post-menopausal breast cancer. The path towards developing obesity and diabetes is affected by multiple factors, including adipokines, inflammatory cytokines, growth hormones, insulin resistance, and hyperlipidemia. The metabolic abnormalities associated with changes in the levels of these factors in obesity and diabetes have the potential to significantly contribute to the development and progression of cancer through the regulation of distinct signaling pathways. Here, we highlight the cellular and molecular pathways that constitute the links between obesity, diabetes, cancer risk and mortality. This includes a description of the existing evidence supporting the obesity-driven morphological and functional alternations of cancer cells and adipocytes through complex interactions within the tumor microenvironment.

Associations between obesity, metabolic health, and the risk of breast cancer in East Asian women

BACKGROUND

This study examined the associations between metabolic syndrome(MetS), obesity, their combination as a metabolic obesity phenotype, and the risk of breast cancer in East Asian postmenopausal women.

METHODS

A total of 3,095,336 postmenopausal cancer-free women aged 40-79 years who underwent the National Health Insurance Service health examination between 2009 and 2010 were included. The incidence of invasive breast cancer was followed up until 2018. The presence of obesity (body mass index[BMI] ≥25 kg/m²), MetS, and each component of MetS was investigated.

RESULTS

Obesity and MetS were associated with breast cancer risk, but when the effects of obesity and MetS were mutually adjusted, the associations were attenuated, especially for MetS. Only elevated fasting blood glucose levels and waist circumference increased the risk of breast cancer after adjusting for BMI. Compared to metabolically healthy normal-weight women, metabolically unhealthy normal-weight women, metabolically healthy obese, and metabolically unhealthy obese women had an increased risk of breast cancer.

CONCLUSIONS

Obesity and MetS were independently associated with an increased risk of breast cancer in postmenopausal women, despite the relationship between MetS and breast cancer appearing to result from a partial association with BMI. Postmenopausal women should be encouraged to control their weight and metabolic health.

Cancer and diabetes: the interlinking metabolic pathways and repurposing actions of antidiabetic drugs

Cancers are regarded as one of the main causes of death and result in high health burden worldwide. The management of cancer include chemotherapy, surgery and radiotherapy. The chemotherapy, which involves the use of chemical agents with cytotoxic actions is utilised as a single treatment or combined treatment. However, these managements of cancer such as chemotherapy poses some setbacks such as cytotoxicity on normal cells and the problem of anticancer drug resistance. Therefore, the use of other therapeutic agents such as antidiabetic drugs is one of the alternative interventions used in addressing some of the limitations in the use of anticancer agents. Antidiabetic drugs such as sulfonylureas, biguanides and thiazolidinediones showed beneficial and repurposing actions in the management of cancer, thus, the activities of these drugs against cancer is attributed to some of the metabolic links between the two disorders and these includes hyperglycaemia, hyperinsulinemia, inflammation, and oxidative stress as well as obesity. Furthermore, some studies showed that the use of antidiabetic drugs could serve as risk factors for the development of cancerous cells particularly pancreatic cancer. However, the beneficial role of these chemical agents overweighs their detrimental actions in cancer management. Hence, the present review indicates the metabolic links between cancer and diabetes and the mechanistic actions of antidiabetic drugs in the management of cancers.

[Type-2-diabetes and cancer risk]

Type-2-diabetes (T2D) increases the risk for several cancers and cancer has become the major cause of death of T2D-patients. T2D is causally associated with colorectal, pancreatic, gallbladder, biliary, hepatocellular, gastric, esophageal, oral, breast, endometrial, ovary, kidney and thyroid cancers as well as leukemias. When T2D goes along with tobacco smoking, alcohol use, physical inactivity, excess body weight, poor diet, familial risk or certain chronic infections, the cumulative cancer risk rises, and T2D-patients often suffer from cancer disease at younger age. T2D-patients should be encouraged to join cancer screening programmes even at younger age than the average non-diabetic population.

Is Gestational Diabetes Mellitus a Risk Factor of Maternal Breast Cancer? A Systematic Review of the Literature

The association between gestational diabetes mellitus (GDM) and breast cancer (BC) risk is complex. We aimed to examine this association in a systematic review of the literature. This review was done using the PubMed/Medline and Web of Science databases, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The Newcastle-Ottawa Scale was used for the assessment of bias and quality of studies. Only English-language articles published before 1 June 2021, were included. Fourteen studies were included in this systematic review. Among them, eight did not find statistically significant results. Three studies showed a statistically significant increased risk of BC after GDM, and they explained this potential increased risk by hyperinsulinemia, hyperglycemia, and low-grade inflammation. However, three studies showed a statistically significant decreased risk of BC after GDM, suggesting a possible protective effect of hormonal changes induced by GDM during pregnancy. These controversial results should be interpreted with caution due to both quantitative and qualitative methodological shortcomings. Further investigations are thus needed in order to gain a better understanding of the associations between GDM and BC, and their underlying mechanisms.

A molecular link between diabetes and breast cancer: Therapeutic potential of repurposing incretin-based therapies for breast cancer

Female breast cancer recently surpassed lung cancer and became the most commonly diagnosed cancer worldwide. As per the recent data from WHO, breast cancer accounts for one out of every 8 cancer cases diagnosed among an estimated 2.3 million new cancer cases. Breast cancer is the most prevailing cancer type among women causing the highest number of cancer-related mortality. It has been estimated that in 2020, 68,5000 women died due to this disease. Breast cancers have varying degrees of molecular heterogeneity; therefore, they are divided into various molecular clinical sub types. Recent reports suggest that type 2 diabetes (one of the common chronic diseases worldwide) is linked to the higher incidence, accelerated progression, and aggressiveness of different cancers; especially breast cancer. Breast cancer is hormone-dependent in nature and has a cross-talk with metabolism. A number of antidiabetic therapies are known to exert beneficial effects on various types of cancers, including breast cancer. However, only a few reports are available on the role of incretin-based antidiabetic therapies in cancer as a whole and in breast cancer in particular. The present review sheds light on the potential of incretin based therapies on breast cancer and explores the plausible underlying mechanisms. Additionally, we have also discussed the sub types of breast cancer as well as the intricate relationship between diabetes and breast cancer.

Potential intrinsic subtype dependence on the association between metformin use and survival in surgically resected breast cancer: a Korean national population-based study

PURPOSE

Numerous studies have suggested that metformin treatment can increase breast cancer survival; however, it is unclear whether its effects interact with intrinsic subtype or diabetic status. Therefore, we conducted a large nationwide study to assess this in women with surgically resected invasive breast cancer.

METHODS

Patients with newly diagnosed breast cancer between 2007 and 2016 were identified using the national health insurance claims database of South Korea. Metformin or other drug exposures was defined as medication for ≥ 90 days. Breast cancer subtypes were classified into four groups based on hormonal therapy and anti-HER2 treatments.

RESULTS

A total of 117,333 patients were included (median follow-up duration, 90 months). Type 2 diabetes mellitus (T2DM) affected significantly overall survival (OS, 7 years, 89.7% vs. 92.4%, p < 0.001). A significant interaction was found between the use of metformin and insulin in patients with T2DM (p = 0.018). Thus, the subsequent analysis was limited to these patients and propensity score matching was performed. We found significantly increased OS in patients treated with metformin (7-year OS, 88.3% vs. 85.6%, p < 0.001). Interestingly, a significant effect was observed in the hormonal therapy (HT)+/HER2-targeted therapy (Tx)- group (p < 0.001), whereas no specific association was observed in the HT-/HER2 Tx- group (p = 0.220).

CONCLUSIONS

Metformin administration may be associated with reduced mortality in patients with surgically resected breast cancer, particularly in the HT+/HER2 Tx- group. Clinical trials investigating metformin as a combination agent in breast cancer should stratify patients by curative resection, intrinsic subtype, the presence of T2DM, and the use of insulin.

The prognostic outcome of 'type 2 diabetes mellitus and breast cancer' association pivots on hypoxia-hyperglycemia axis

Type 2 diabetes mellitus and breast cancer are complex, chronic, heterogeneous, and multi-factorial diseases; with common risk factors including but not limited to diet, obesity, and age. They also share mutually inclusive phenotypic features such as the metabolic deregulations resulting from hyperglycemia, hypoxic conditions and hormonal imbalances. Although, the association between diabetes and cancer has long been speculated; however, the exact molecular nature of this link remains to be fully elucidated. Both the diseases are leading causes of death worldwide and a causal relationship between the two if not addressed, may translate into a major global health concern. Previous studies have hypothesized hyperglycemia, hyperinsulinemia, hormonal imbalances and chronic inflammation, as some of the possible grounds for explaining how diabetes may lead to cancer initiation, yet further research still needs to be done to validate these proposed mechanisms. At the crux of this dilemma, hyperglycemia and hypoxia are two intimately related states involving an intricate level of crosstalk and hypoxia inducible factor 1, at the center of this, plays a key role in mediating an aggressive disease state, particularly in solid tumors such as breast cancer. Subsequently, elucidating the role of HIF1 in establishing the diabetes-breast cancer link on hypoxia-hyperglycemia axis may not only provide an insight into the molecular mechanisms underlying the association but also, illuminate on the prognostic outcome of the therapeutic targeting of HIF1 signaling in diabetic patients with breast cancer or vice versa. Hence, this review highlights the critical role of HIF1 signaling in patients with both T2DM and breast cancer, potentiates its significance as a prognostic marker in comorbid patients, and further discusses the potential prognostic outcome of targeting HIF1, subsequently establishing the pressing need for HIF1 molecular profiling-based patient selection leading to more effective therapeutic strategies emerging from personalized medicine.

Breast Cancer, Diabetes Mellitus and Glucagon-Like Peptide-1 Receptor Toward Exploring Their Possible Associations

PURPOSE

Diabetes Mellitus (DM) has been one of the well known risk factors of breast cancer (BC) development and also associated with adverse clinical outcomes of BC patients. Glucagon-like peptide-1 (GLP-1) receptor agonists have been used as antidiabetic therapeutic agents and recent epidemiological studies have reported their use to be correlated with increased BC risks. However, biological or pathological details have remained unknown. Therefore, in this study, we examined the status of GLP-1 receptor (GLP-1R) in BC with and without DM and correlated the findings with the clinicopathological factors of the patients to explore the possible involvement of GLP-1 in BC pathology.

METHODS

We immunolocalized GLP-1R in cancer and adjacent non-pathological breast tissues in BC patients with DM (125 cases) and without DM (58 cases). We then compared the status of GLP-1R with that of fibroblast growth factor 7 (FGF7) and fibroblast growth factor receptor 2 (FGFR2), Ki-67 labeling index (Ki-67 LI) and disease free survival (DFS) of the patients and also between cancerous and non-pathological breast tissues.

RESULTS

GLP-1R immunoreactivity was significantly higher (p = 0.044) in the patients with DM than without in carcinoma tissues. However, this was detected only in invasive carcinoma (p < 0.01) and not in non-invasive carcinoma nor non-pathological mammary glands. FGF7 was significantly correlated with the status of GLP-1R in BC (p = 0.045). In addition, in ER positive BC cases, those with GLP-1R positive status tended to have higher Ki-67 LI of more than 14% (p = 0.070).

CONCLUSION

These findings all demonstrated the possible association between GLP-1R status and biological features of BC, especially of invasive BC in DM patients.

The Triple Health Threat of Diabetes, Obesity, and Cancer-Epidemiology, Disparities, Mechanisms, and Interventions

Obesity and type 2 diabetes are both chronic, relapsing, progressive diseases that are recognized as risk factors for the development of multiple types of cancer. In a recent symposium titled "Hitting A Triple-Diabetes, Obesity, and the Emerging Links to Cancer Risk," convened by The Obesity Society during ObesityWeek 2019, experts in the field presented the current science and highlighted existing research gaps. Topics included (1) the epidemiology of obesity and diabetes and their links to cancer risk; (2) racial and ethnic differences in obesity, diabetes, and cancer risk; (3) biological mechanisms common to obesity and diabetes that may increase cancer risk; and (4) innovative interventions that can be used to prevent the development of cancers related to obesity and diabetes. This report provides an overview of the symposium and describes key research gaps and pressing questions in need of answers to advance the field. The collective burden of obesity, diabetes, and cancer represents one of the largest public health challenges of the century. Although the symposium was titled "hitting a triple," it was recognized that being able to disrupt the linkages among obesity, diabetes, and cancer would be a "grand slam" for public health and medicine.

Normalizing glucose levels reconfigures the mammary tumor immune and metabolic microenvironment and decreases metastatic seeding

Obesity and diabetes cumulatively create a distinct systemic metabolic pathophysiological syndrome that predisposes patients to several diseases including breast cancer. Moreover, diabetic and obese women with breast cancer show a significant increase in mortality compared to non-obese and/or non-diabetic women. We hypothesized that these metabolic conditions incite an aggressive tumor phenotype by way of impacting tumor cell-autonomous and tumor cell non-autonomous events. In this study, we established a type 2 diabetic mouse model of triple-negative mammary carcinoma and investigated the effect of a glucose lowering therapy, metformin, on the overall tumor characteristics and immune/metabolic microenvironment. Diabetic mice exhibited larger mammary tumors that had increased adiposity with high levels of O-GlcNAc protein post-translational modification. These tumors also presented with a distinct stromal profile characterized by altered collagen architecture, increased infiltration by tumor-permissive M2 macrophages, and early metastatic seeding compared to non-diabetic/lean mice. Metformin treatment of the diabetic/obese mice effectively normalized glucose levels, reconfigured the mammary tumor milieu, and decreased metastatic seeding. Our results highlight the impact of two metabolic complications of obesity and diabetes on tumor cell attributes and showcase metformin's ability to revert tumor cell and stromal changes induced by an obese and diabetic host environment.

Hyperinsulinemia in Obesity, Inflammation, and Cancer

The relative insufficiency of insulin secretion and/or insulin action causes diabetes. However, obesity and type 2 diabetes mellitus can be associated with an absolute increase in circulating insulin, a state known as hyperinsulinemia. Studies are beginning to elucidate the cause-effect relationships between hyperinsulinemia and numerous consequences of metabolic dysfunctions. Here, we review recent evidence demonstrating that hyperinsulinemia may play a role in inflammation, aging and development of cancers. In this review, we will focus on the consequences and mechanisms of excess insulin production and action, placing recent findings that have challenged dogma in the context of the existing body of literature. Where relevant, we elaborate on the role of specific signal transduction components in the actions of insulin and consequences of chronic hyperinsulinemia. By discussing the involvement of hyperinsulinemia in various metabolic and other chronic diseases, we may identify more effective therapeutics or lifestyle interventions for preventing or treating obesity, diabetes and cancer. We also seek to identify pertinent questions that are ripe for future investigation.

Making sense of associations between type 2 diabetes, metformin, and breast cancer risk

The relationship between type 2 diabetes (T2D), metformin, and breast cancer is complex. T2D may increase risk, but metformin used as first-line treatment of T2D may decrease breast cancer risk. This comment explores efforts to disentangle effects of T2D and metformin use on breast cancer risk in a prospective study.

De Novo Cancer Incidence after Cholecystectomy in Korean Population

Background: Cancer development after cholecystectomy remains debatable. We estimated the major cancer incidence rates after cholecystectomy stratified by age and sex. Methods: The records of 408,769 subjects aged >20 years were extracted from the National Health Insurance database from 2008 to 2016. The risks of major cancers were compared between the cholecystectomy and general populations using standardised incidence ratios (SIR). Results: The overall cancer incidence was comparable between cholecystectomy patients and the general population. However, patients aged <65 years who underwent cholecystectomy had a higher cancer risk than those aged ≥65 years and the general population (SIR 2.62; 95% confidence interval [CI] 2.15–3.08; SIR 1.36, 95% CI 1.32–1.40; and SIR 0.90, 95% CI 0.87–0.92 in men and SIR 1.91; 95% CI 1.71–2.10; SIR 1.07; 95% CI 1.03–1.10; and SIR 0.90; 95% CI 0.87–0.94 in women aged 20–34, 35–64, and ≥65 years at cholecystectomy). Colorectal and liver cancer incidences after cholecystectomy were higher than those in the general population regardless of age group and sex (SIR, 1.55 for colorectal cancer in men and women; SIR, 1.25 and 1.51 for liver cancer in men and women, respectively). However, for other major cancers, the risk was higher in patients who underwent cholecystectomy at a younger age than in those who underwent cholecystectomy at an age ≥65 years. Conclusion: Patients with cholecystectomy, especially those undergoing cholecystectomy at a younger age, need preventive strategies based on the cancer type.

Hyperglycemia-Induced miR-467 Drives Tumor Inflammation and Growth in Breast Cancer

The tumor microenvironment contains the parenchyma, blood vessels, and infiltrating immune cells, including tumor-associated macrophages (TAMs). TAMs affect the developing tumor and drive cancer inflammation. We used mouse models of hyperglycemia and cancer and specimens from hyperglycemic breast cancer (BC) patients to demonstrate that miR-467 mediates the effects of high blood glucose on cancer inflammation and growth. Hyperglycemic patients have a higher risk of developing breast cancer. We have identified a novel miRNA-dependent pathway activated by hyperglycemia that promotes BC angiogenesis and inflammation supporting BC growth. miR-467 is upregulated in endothelial cells (EC), macrophages, BC cells, and in BC tumors. A target of miR-467, thrombospondin-1 (TSP-1), inhibits angiogenesis and promotes resolution of inflammation. Systemic injections of a miR-467 antagonist in mouse models of hyperglycemia resulted in decreased BC growth (p < 0.001). Tumors from hyperglycemic mice had a two-fold increase in macrophage accumulation compared to normoglycemic controls (p < 0.001), and TAM infiltration was prevented by the miR-467 antagonist (p < 0.001). BC specimens from hyperglycemic patients had increased miR-467 levels, increased angiogenesis, decreased levels of TSP-1, and increased TAM infiltration in malignant breast tissue in hyperglycemic vs. normoglycemic patients (2.17-fold, p = 0.002) and even in normal breast tissue from hyperglycemic patients (2.18-fold increase, p = 0.04). In malignant BC tissue, miR-467 levels were upregulated 258-fold in hyperglycemic patients compared to normoglycemic patients (p < 0.001) and increased 56-fold in adjacent normal tissue (p = 0.008). Our results suggest that miR-467 accelerates tumor growth by inducing angiogenesis and promoting the recruitment of TAMs to drive hyperglycemia-induced cancer inflammation.

Diabetes, Obesity, and Inflammation: Impact on Clinical and Radiographic Features of Breast Cancer

Obesity, diabetes, and inflammation increase the risk of breast cancer, the most common malignancy in women. One of the mainstays of breast cancer treatment and improving outcomes is early detection through imaging-based screening. There may be a role for individualized imaging strategies for patients with certain co-morbidities. Herein, we review the literature regarding the accuracy of conventional imaging modalities in obese and diabetic women, the potential role of anti-inflammatory agents to improve detection, and the novel molecular imaging techniques that may have a role for breast cancer screening in these patients. We demonstrate that with conventional imaging modalities, increased sensitivity often comes with a loss of specificity, resulting in unnecessary biopsies and overtreatment. Obese women have body size limitations that impair image quality, and diabetes increases the risk for dense breast tis-sue. Increased density is known to obscure the diagnosis of cancer on routine screening mammography. Novel molecu-lar imaging agents with targets such as estrogen receptor, human epidermal growth factor receptor 2 (HER2), pyrimi-dine analogues, and ligand-targeted receptor probes, among others, have potential to reduce false positive results. They can also improve detection rates with increased resolution and inform therapeutic decision making. These emerg-ing imaging techniques promise to improve breast cancer diagnosis in obese patients with diabetes who have dense breasts, but more work is needed to validate their clinical application.

Dairy Consumption and Incidence of Breast Cancer in the 'Seguimiento Universidad de Navarra' (SUN) Project

Dairy products might influence breast cancer (BC) risk. However, evidence is inconsistent. We sought to examine the association between dairy product consumption-and their subtypes-and incident BC in a Mediterranean cohort. The SUN ("Seguimiento Universidad de Navarra") Project is a Spanish dynamic ongoing cohort of university graduates. Dairy product consumption was estimated through a previously validated 136-item food frequency questionnaire (FFQ). Incident BC was reported in biennial follow-up questionnaires and confirmed with revision of medical records and consultation of the National Death Index. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated with Cox regression models. Among 123,297 women-years of follow-up (10,930 women, median follow-up 12.1 years), we confirmed 119 incident BC cases. We found a nonlinear association between total dairy product consumption and BC incidence (p_nonlinear = 0.048) and a significant inverse association for women with moderate total dairy product consumption (HR_Q2vs.Q1 = 0.49 (95% CI 0.28-0.84); HR_Q3vs.Q1 = 0.49 (95% CI 0.29-0.84) p_trend = 0.623) and with moderate low-fat dairy product consumption (HR_Q2vs.Q1 = 0.58 (95% CI 0.35-0.97); HR_Q3vs.Q1 = 0.55 (95% CI 0.32-0.92), p_trend = 0.136). In stratified analyses, we found a significant inverse association between intermediate low-fat dairy product consumption and premenopausal BC and between medium total dairy product consumption and postmenopausal BC. Thus, dairy products, especially low-fat dairy products, may be considered within overall prudent dietary patterns.

Obesity, Type 2 Diabetes, and Cancer Risk

Obesity and type 2 diabetes have both been associated with increased cancer risk and are becoming increasingly prevalent. Metabolic abnormalities such as insulin resistance and dyslipidemia are associated with both obesity and type 2 diabetes and have been implicated in the obesity-cancer relationship. Multiple mechanisms have been proposed to link obesity and diabetes with cancer progression, including an increase in insulin/IGF-1 signaling, lipid and glucose uptake and metabolism, alterations in the profile of cytokines, chemokines, and adipokines, as well as changes in the adipose tissue directly adjacent to the cancer sites. This review aims to summarize and provide an update on the epidemiological and mechanistic evidence linking obesity and type 2 diabetes with cancer, focusing on the roles of insulin, lipids, and adipose tissue.

Novel Aza-podophyllotoxin derivative induces oxidative phosphorylation and cell death via AMPK activation in triple-negative breast cancer

BACKGROUND

To circumvent Warburg effect, several clinical trials for different cancers are utilising a combinatorial approach using metabolic reprogramming and chemotherapeutic agents including metformin. The majority of these metabolic interventions work via indirectly activating AMP-activated protein kinase (AMPK) to alter cellular metabolism in favour of oxidative phosphorylation over aerobic glycolysis. The effect of these drugs is dependent on glycaemic and insulin conditions.  Therefore, development of small molecules, which can activate AMPK, irrespective of the energy state, may be a better approach for triple-negative breast cancer (TNBC) treatment.

METHODS

Therapeutic effect of SU212 on TNBC cells was examined using in vitro and in vivo models.

RESULTS

We developed and characterised the efficacy of novel AMPK activator (SU212) that selectively induces oxidative phosphorylation and decreases glycolysis in TNBC cells, while not affecting these pathways in normal cells.   SU212 accomplished this metabolic reprogramming by activating AMPK independent of energy stress and irrespective of the glycaemic/insulin state. This leads to mitotic phase arrest and apoptosis in TNBC cells. In vivo, SU212 inhibits tumour growth, cancer progression and metastasis.

CONCLUSIONS

SU212 directly activates AMPK in TNBC cells, but does not hamper glucose metabolism in normal cells. Our study provides compelling preclinical data for further development of SU212 for the treatment of TNBC.

A prospective study of type 2 diabetes, metformin use, and risk of breast cancer

BACKGROUND

Type 2 diabetes (T2D) has been associated with increased breast cancer risk, but commonly prescribed antidiabetic medications such as metformin may reduce risk. Few studies have investigated T2D and medications together in relation to breast cancer.

PATIENTS AND METHODS

Data came from 44 541 Sister Study participants aged 35 to 74 years at enrollment (2003-2009) who satisfied eligibility criteria, followed through 15 September 2017. Information on time-varying, self-reported, physician-diagnosed, prevalent and incident T2D, use of antidiabetic medications, and covariates was obtained from baseline and follow-up questionnaires. Incident breast cancers were confirmed with medical records. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated.

RESULTS

During follow-up (median, 8.6 years), 2678 breast cancers were diagnosed at least 1 year after enrollment. There were 3227 women (7.2%) with prevalent and 2389 (5.3%) with incident T2D, among whom 61% (n = 3386) were ever treated with metformin. There was no overall association between T2D and breast cancer risk (HR 0.99; 95% CI, 0.87-1.13). However, T2D was associated with increased risk of triple-negative breast cancer (HR 1.40; 95% CI, 0.90-2.16). Compared with not having T2D, T2D with metformin use was not associated with overall breast cancer risk (HR 0.98; 95% CI, 0.83-1.15), but it was associated with decreased risk of estrogen receptor (ER)-positive breast cancer (HR 0.86; 95% CI 0.70-1.05) and increased risk of ER-negative (HR 1.25; 95% CI, 0.84-1.88) and triple-negative breast cancer (HR 1.74; 95% CI, 1.06-2.83). The inverse association with ER-positive cancer was stronger for longer duration (≥10 year) metformin use (HR 0.62; 95% CI, 0.38-1.01; P for trend = 0.09). Results were supported by sensitivity analyses.

CONCLUSION

Our findings suggest that associations between T2D and breast cancer may differ by hormone receptor status and that associations between T2D and ER-positive breast cancer may be reduced by long-term metformin use.

Comorbidity Management in Black Women Diagnosed with Breast Cancer: the Role of Primary Care in Shared Care

BACKGROUND

Black women are more likely to have comorbidity at breast cancer diagnosis compared with White women, which may account for half of the Black-White survivor disparity. Comprehensive disease management requires a coordinated team of healthcare professionals including primary care practitioners, but few studies have examined shared care in the management of comorbidities during cancer care, especially among racial/ethnic minorities.

OBJECTIVE

To examine whether the type of medical team composition is associated with optimal clinical care management of comorbidities.

DESIGN

We used the Women's Circle of Health Follow-up Study, a population-based cohort of Black women diagnosed with breast cancer. The likelihood of receiving optimal comorbidity management after breast cancer diagnosis was compared by type of medical team composition (shared care versus cancer specialists only) using binomial regression.

PARTICIPANTS

Black women with a co-diagnosis of diabetes and/or hypertension at breast cancer diagnosis between 2012 and 2016 (N = 274).

MAIN MEASURES

Outcome-optimal clinical care management of diabetes (i.e., A1C test, LDL-C test, and medical attention for nephropathy) and hypertension (i.e., lipid screening and prescription for hypertension medication). Main predictor-shared care, whether the patient received care from both a cancer specialist and a primary care provider and/or a medical specialist within the 12 months following a breast cancer diagnosis.

KEY RESULTS

Primary care providers were the main providers involved in managing comorbidities and 90% of patients received shared care during breast cancer care. Only 54% had optimal comorbidity management. Patients with shared care were five times (aRR: 4.62; 95% CI: 1.66, 12.84) more likely to have optimal comorbidity management compared with patients who only saw cancer specialists.

CONCLUSIONS

Suboptimal management of comorbidities during breast cancer care exists for Black women. However, our findings suggest that shared care is more beneficial at achieving optimal clinical care management for diabetes and hypertension than cancer specialists alone.

Cross Talk between COVID-19 and Breast Cancer

Cancer patients are more susceptible to COVID-19; however, the prevalence of COVID-19 in different types of cancer is still inconsistent and inconclusive. Here, we delineate the intricate relationship between breast cancer and COVID-19. Breast cancer and COVID-19 share the involvement of common comorbidities, hormonal signalling pathways, gender differences, rennin- angiotensin system (RAS), angiotensin-converting enzyme-2 (ACE-2), transmembrane protease serine 2 (TMPRSS2) and dipeptidyl peptidase-IV (DPP-IV). We also shed light on the possible effects of therapeutic modalities of COVID-19 on breast cancer outcomes. Briefly, we conclude that breast cancer patients are more susceptible to COVID-19 in comparison with their normal counterparts. Women are more resistant to the occurrence and severity of COVID-19. Increased expressions of ACE2 and TMPRSS2 are correlated with occurrence and severity of COVID-19, but higher expression of ACE2 and lower expression of TMPRSS2 are prognostic markers for overall disease free survival in breast cancer. The ACE2 inhibitors and ibuprofen therapies for COVID-19 treatment may aggravate the clinical condition of breast cancer patients through chemo-resistance and metastasis. Most of the available therapeutic modalities for COVID-19 were also found to exert positive effects on breast cancer outcomes. Besides drugs in clinical trend, TMPRSS2 inhibitors, estrogen supplementation, androgen deprivation and DPP-IV inhibitors may also be used to treat breast cancer patients infected with SARS-CoV-2. However, drug-drug interactions suggest that some of the drugs used for the treatment of COVID-19 may modulate the drug metabolism of anticancer therapies which may lead to adverse drug reaction events.

Short-Chain Fatty Acids: A Soldier Fighting Against Inflammation and Protecting From Tumorigenesis in People With Diabetes

Converging evidences showed that people with diabetes mellitus (DM) have significantly higher risk for different cancers, of which the exact mechanism underlying the association has not been fully realized. Short-chain fatty acids (SCFAs), the fermentation products of the intestinal microbiota, are an essential source for energy supply in gut epithelial cells. They have been reported to improve intestinal barrier integrity, prevent microbial translocation, and further dampen inflammation. Gut dysbiosis and reduction in SCFA-producing bacteria as well as SCFAs production in the intestine are commonly seen in metabolic disorders including DM and obesity. Moreover, inflammation can contribute to tumor initiation and progression through multiple pathways, such as enhancing DNA damage, accumulating mutations in tumor suppressor genes Tp53, and activating nuclear factor-kappa B (NF-κB) signaling pathways. Based on these facts, we hypothesize that lower levels of microbial SCFAs resulted from gut dysbiosis in diabetic individuals, enhance microbial translocation, and increase the inflammatory responses, inducing tumorigenesis ulteriorly. To this end, we will discuss protective properties of microbial SCFAs and explore the pivotal roles SCFAs played in the link of DM with cancer, so as to take early precautions to reduce the risk of cancer in patients with DM.

LDL, HDL and endocrine-related cancer: From pathogenic mechanisms to therapies

Cholesterol is essential for a variety of functions in endocrine-related cells, including hormone and steroid production. We have reviewed the progress to date in research on the role of the main cholesterol-containing lipoproteins; low-density lipoprotein (LDL) and high-density lipoprotein (HDL), and their impact on intracellular cholesterol homeostasis and carcinogenic pathways in endocrine-related cancers. Neither LDL-cholesterol (LDL-C) nor HDL-cholesterol (HDL-C) was consistently associated with endocrine-related cancer risk. However, preclinical studies showed that LDL receptor plays a critical role in endocrine-related tumor cells, mainly by enhancing circulating LDL-C uptake and modulating tumorigenic signaling pathways. Although scavenger receptor type BI-mediated uptake of HDL could enhance cell proliferation in breast, prostate, and ovarian cancer, these effects may be counteracted by the antioxidant and anti-inflammatory properties of HDL. Moreover, 27-hydroxycholesterol a metabolite of cholesterol promotes tumorigenic processes in breast and epithelial thyroid cancer. Furthermore, statins have been reported to reduce the incidence of breast, prostate, pancreatic, and ovarian cancer in large clinical trials, in part because of their ability to lower cholesterol synthesis. Overall, cholesterol homeostasis deregulation in endocrine-related cancers offers new therapeutic opportunities, but more mechanistic studies are needed to translate the preclinical findings into clinical therapies.

Effects of leptin on the viability of MCF-7 and T47D cells at different glucose concentrations

Obesity is associated with increased risk of breast cancer. Leptin is a well-known factor involved in obesity and its serum levels are increased in breast cancer. Hyperglycemia is another significant risk factor for breast cancer. Consistently, high glucose induces proliferation and invasion of breast cancer cells and in-vivo calorie restriction reduce tumorigenesis in rodent models. The aim of this study was to investigate the effect of leptin on the viability and mode of cell death in breast cancer cells incubated in different glucose concentrations to represent caloric restriction. For this purpose, MCF-7 and T47D breast cancer cells incubated in different glucose concentrations for a total of 72 hours were treated with or without leptin either for one hour or 24 hours and the ratio of apoptotic, necrotic and alive cells were analyzed by flow cytometry. Our data revealed that glucose incubation significantly decreased apoptosis and necrosis, while increasing viability in both cell lines in a dose dependent manner. One-hour leptin treatment significantly decreased viability, and increased apoptosis but did not significantly affect necrosis in T47D cells incubated in 2.5 mM glucose. In MCF-7 cells, one-hour leptin incubation significantly increased necrosis but its effects on apoptosis and viability were not significant. In conclusion, although glucose induces cell death by apoptosis and necrosis in T47D and MCF-7 cells respectively in a dose dependent manner, the overallviability is still increased in both cell lines. One-hour leptin treatment reverses the effect of low glucose incubation on apoptosis of T47D and necrosis of MCF-7 cells. Moreover, the effect of one-hour leptin treatment on apoptosis or necrosis is significantly higher than that of 24-hour leptin treatment.

Type 2 Diabetes Mellitus Induced Paracrine Effects on Breast Cancer Metastasis Through Extracellular Vesicles Derived from Human Mesenchymal Stem Cells

Cancer metastasis is the leading cause of mortality among breast cancer patients. Type 2 diabetes mellitus (T2DM) has been suggested as a risk factor of breast cancer; however, whether or not T2DM is associated with breast tumor metastasis remains unclear. In this study, we examined the involvement of T2DM with breast cancer metastasis by a combined approach of a meta-analysis and experimental research. The results of a systematic review and meta-analysis suggested that diabetes significantly increases the risk of lymph node metastasis by 1.10-fold (P < 0.01). Consistently, our data from experimental research showed that T2DM induced paracrine effects of mesenchymal stem cells (MSCs), a key contributor to cancer progression, to stimulate metastasis of breast cancer cells (BCCs) by two independent mechanisms. First, T2DM induced the excess secretion of interleukin 6 (IL6) from MSCs, which activated the JAK/STAT3 pathway in BCCs, thus promoting the metastasis of BCCs. Second, beside the EGR-1-/IL6-dependent mechanism, T2DM altered the functions of MSC-derived extracellular vesicles (EVs), which are highly associated with the metastasis of BCCs. Our present study showed that T2DM is a risk factor for breast cancer metastasis, and MSC-derived EVs might be useful for developing a novel anti-breast cancer therapy strategy.

NLRP3 as Putative Marker of Ipilimumab-Induced Cardiotoxicity in the Presence of Hyperglycemia in Estrogen-Responsive and Triple-Negative Breast Cancer Cells

Hyperglycemia, obesity and metabolic syndrome are negative prognostic factors in breast cancer patients. Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment, achieving unprecedented efficacy in multiple malignancies. However, ICIs are associated with immune-related adverse events involving cardiotoxicity. We aimed to study if hyperglycemia could affect ipilimumab-induced anticancer efficacy and enhance its cardiotoxicity. Human cardiomyocytes and estrogen-responsive and triple-negative breast cancer cells (MCF-7 and MDA-MB-231 cell lines) were exposed to ipilimumab under high glucose (25 mM); low glucose (5.5 mM); high glucose and co-administration of SGLT-2 inhibitor (empagliflozin); shifting from high glucose to low glucose. Study of cell viability and the expression of new putative biomarkers of cardiotoxicity and resistance to ICIs (NLRP3, MyD88, cytokines) were quantified through ELISA (Cayman Chemical) methods. Hyperglycemia during treatment with ipilimumab increased cardiotoxicity and reduced mortality of breast cancer cells in a manner that is sensitive to NLRP3. Notably, treatment with ipilimumab and empagliflozin under high glucose or shifting from high glucose to low glucose reduced significantly the magnitude of the effects, increasing responsiveness to ipilimumab and reducing cardiotoxicity. To our knowledge, this is the first evidence that hyperglycemia exacerbates ipilimumab-induced cardiotoxicity and decreases its anticancer efficacy in MCF-7 and MDA-MB-231 cells. This study sets the stage for further tests on other breast cancer cell lines and primary cardiomyocytes and for preclinical trials in mice aimed to decrease glucose through nutritional interventions or administration of gliflozines during treatment with ipilimumab.

High-sensitivity C-reactive protein, hemoglobin A1c and breast cancer risk: a nested case-control study from Alberta's Tomorrow Project cohort

PURPOSE

Our aim is to examine the associations between high-sensitivity C-reactive protein (hsCRP) and hemoglobin A1c (HbA1c), common biomarkers of inflammation and insulin resistance, respectively, with breast cancer risk, while adjusting for measures of excess body size.

METHODS

We conducted a nested case-control study within the Alberta's Tomorrow Project cohort (Alberta, Canada) including 197 incident breast cancer cases and 394 matched controls. The sample population included both pre- and postmenopausal women. Serum concentrations of hsCRP and HbA1c were measured from blood samples collected at baseline, along with anthropometric measurements, general health and lifestyle data. Conditional logistic regression was used to evaluate associations between hsCRP, HbA1c, and breast cancer risk adjusted for excess body size (body fat percentage) and other risk factors for breast cancer.

RESULTS

Higher concentrations of hsCRP were associated with elevated breast cancer risk (odds ratio [OR] 1.27; 95% confidence interval [95% CI] 1.03-1.55). The observed associations were unchanged with adjustment for body fat percentage. Higher HbA1c concentrations were not significantly associated with an increased breast cancer risk (OR 1.22; 95% CI 0.17-8.75).

CONCLUSION

These data suggest that hsCRP may be associated with elevated breast cancer risk, independent of excess body size. However, elevated concentrations of HbA1c did not appear to increase breast cancer risk in apparently healthy women.

Holothuria scabra Extract Induces Cell Apoptosis and Suppresses Warburg Effect by Down-Regulating Akt/mTOR/HIF-1 Axis in MDA-MB-231 Breast Cancer Cells

INTRODUCTION

Cancer cells utilize the modified glucose metabolism known as Warburg effect, with lactate production as the end product. In the search for alternative therapy, the body wall of sea cucumbers contains various substances with pharmacological activities. Herein, we investigate the effect of Holothuria scabra extract on the viability and Warburg effect of aggressive breast cancer cells.

METHODS

Body wall of H. scabra was extracted using 95% ethanol. Triple-negative breast cancer cells, MDA-MB-231, were treated with the extract at various concentrations under normoglycemic and hyperglycemic conditions. Cytotoxicity test was performed using MTT assay. Apoptotic proteins were quantified using Western blot. Apoptotic cells were stained with Hoechst 33342. Lactate production was determined using L-lactate assay kit.

RESULTS

By MTT assay, H. scabra extract suppressed the viability of breast cancer cells in a dose-dependent and time-dependent manner by enhancing apoptosis, indicated by a marked increase of proapoptotic Bax and pro-caspase three expressions, and decreased expression of anti-apoptotic Bcl-2. The extract could reduce hexokinase II expression, leading to reduced lactate production by blocking the Akt/mTOR/HIF-1 axis.

DISCUSSION

Overall findings indicated that H. scabra extract could be a possible therapeutic against breast cancer progression in patients with hyperglycemia, for instance, diabetes mellitus.

Treatment of ErbB2 breast cancer by mitochondrial targeting

Background

ErbB2 breast cancer still remains an unmet need due to primary and/or acquired resistance to current treatment strategies. MEDICA compounds consist of synthetic long-chain α,ω-dicarboxylic acids previously reported to suppress breast cancer in PyMT transgenic mice.

Methods

MEDICA efficacy and mode of action in the ErbB2 context was studied in ErbB2 transgenic mice and human breast cancer cells.

Results

MEDICA treatment is shown here to suppress ErbB2 breast tumors and lung metastasis in ErbB2/neu MMTV transgenic mice, to suppress ErbB2/neu xenografts in nod/scid mice, and to suppress survival of AU565 and BT474 human ErbB2 breast cancer cells. Suppression of ErbB2 breast tumors by MEDICA is due to lipid raft disruption with loss of ErbB family members, including EGFR, ErbB2, and ErbB3. In addition, MEDICA inhibits mTORC1 activity, independently of abrogating the ErbB receptors and their signaling cascades. The double hit of MEDICA in abrogating ErbB and mTORC1 is partly accounted for by targeting mitochondria complex I.

Conclusions

Mitochondrial targeting by MEDICA suppresses ErbB2 breast tumors and metastasis due to lipid raft disruption and inhibition of mTORC1 activity. Inhibition of mTORC1 activity by MEDICA avoids the resistance acquired by canonical mTORC1 inhibitors like rapalogs or mTOR kinase inhibitors.

Diabetes and cancer: Epidemiological and biological links

The incidence of diabetes and cancer has increased significantly in recent years. Furthermore, there are many common risk factors for both diabetes and cancer, such as obesity, sedentary lifestyle, smoking, and ageing. A large body of epidemiological evidence has indicated that diabetes is considered as an independent risk factor for increased rates of heterogeneous types of cancer occurrence and death. The incidence and mortality of various types of cancer, such as pancreas, liver, colorectal, breast, endometrial, and bladder cancers, have a modest growth in diabetics. However, diabetes may work as a protective factor for prostate cancer. Although the underlying biological mechanisms have not been totally understood, studies have validated that insulin/insulin-like growth factor (IGF) axis (including insulin resistance, hyperinsulinemia, and IGF), hyperglycemia, inflammatory cytokines, and sex hormones provide good circumstances for cancer cell proliferation and metastasis. Insulin/IGF axis activates several metabolic and mitogenic signaling pathways; hyperglycemia provides energy for cancer cell growth; inflammatory cytokines influence cancer cell apoptosis. Thus, these three factors affect all types of cancer, while sex hormones only play important roles in breast cancer, endometrial cancer, and prostate cancer. This minireview consolidates and discusses the epidemiological and biological links between diabetes and various types of cancer.

Impact of preexisting type 2 diabetes mellitus and antidiabetic drugs on all-cause and cause-specific mortality among Medicaid-insured women diagnosed with breast cancer

BACKGROUND

We investigated the influence preexisting type 2 diabetes mellitus (T2DM) and antidiabetic drugs have on all-cause and cause-specific mortality among Medicaid-insured women diagnosed with breast cancer.

METHODS

9221 women aged <64 years diagnosed with breast cancer and reported to the New York State (NYS) Cancer Registry from 2004 to 2016 were linked with Medicaid claims. Preexisting T2DM was determined by three diagnosis claims for T2DM with at least one claim prior to breast cancer diagnosis and a prescription claim for an antidiabetic drug within three months following breast cancer diagnosis. Estimated menopausal status was determined by age (premenopausal age <50; postmenopausal age ≥50). Hazard ratios (HR) and 95 % confidence intervals (95 %CI) were calculated with Cox proportional hazards regression, adjusting for confounders.

RESULTS

Women with preexisting T2DM had greater all-cause (HR = 1.40; 95 %CI 1.21, 1.63), cancer-specific (HR = 1.24; 95 %CI 1.04, 1.47), and cardiovascular-specific (HR = 2.46; 95 %CI 1.54, 3.90) mortality hazard compared to nondiabetic women. In subgroup analyses, the association between T2DM and all-cause mortality was found among non-Hispanic White (HR 1.78 95 %CI 1.38, 2.30) and postmenopausal (HR = 1.47; 95 %CI 1.23, 1.77) women, but not among other race/ethnicity groups or premenopausal women. Additionally, compared to women prescribed metformin, all-cause mortality hazard was elevated among women prescribed sulfonylurea (HR = 1.44; 95 %CI 1.06, 1.94) or insulin (HR = 1.54; 95 %CI 1.12, 2.11).

CONCLUSION

Among Medicaid-insured women with breast cancer, those with preexisting T2DM have an increased mortality hazard, especially when prescribed sulfonylurea or insulin. Further research is warranted to determine the role antidiabetic drugs have on survival among women with breast cancer.

Diabetes as a Risk Factor for Breast Cancer

Diabetes is one of the most important chronic conditions worldwide, and breast cancer is the most prevalent cancer in women worldwide. Several types of research have been conducted to ascertain the link between diabetes and its potential for increasing the risk of breast cancer. This research aims to determine the relationship between diabetes and breast cancer; patients with diabetes have a higher risk than the general population of developing cancer, and diabetes patients have a higher incidence and mortality of breast cancer. This research also reviewed the relationship between cytokines, the mitogenic effect of insulin-like growth factors, and breast cells. The review includes searching the PubMed database using the keywords "diabetes," "breast cancer," "risk factor," and "premenopausal." The search returned 53 articles used for review of this article.

Gestational Diabetes and Risk of Breast Cancer in African American Women

BACKGROUND

Gestational diabetes mellitus (GDM) has been hypothesized to increase breast cancer risk, but results from the few prior epidemiologic studies are conflicting, and no studies have examined the association in African American women.

METHODS

We analyzed data from the prospective Black Women's Health Study to evaluate associations of history of GDM with breast cancer risk among 41,767 parous African American women, adjusting for potential confounders. HRs and 95% confidence intervals (CI) were estimated from multivariable Cox proportional hazards regression models.

RESULTS

There was no evidence of an association between history of GDM and risk of invasive breast cancer, overall or by estrogen receptor status.

CONCLUSIONS

Results of this study do not support the hypothesis that GDM is an important risk factor for breast cancer in African American women overall.

IMPACT

On the basis of these data, breast cancer risk is not increased among African American women with a history of GDM compared with parous women without a history of GDM.

History of Diabetes Mellitus and Risk of Breast Cancer in Asian Women: A Meta-Epidemiological Analysis of Population-Based Cohort Studies

Objectives

Previous quantitative systematic reviews conducting subgroup analyses by race have reported that the association between diabetes and breast cancer in Asian women was inconclusive. The aim of this meta-epidemiological study (MES) was to evaluate this association from additional population-based cohort studies.

Methods

The potential subjects of this MES were six Asian cohort studies selected by previous systematic reviews. Additional reports were found from the selected articles using citation discovery tools. The study with the longest follow-up period was selected among prospective studies of the same cohorts. A summary relative risk (sRR) and its 95% confidence intervals (CI) were calculated using random effect models.

Results

Four cohort studies on Asian women were finally selected. The participants were from the women population of Korea, Japan, China, and Taiwan and included a total of 1,448,254 women. The sRR (95% CI) (I-squared value) was 1.20 (0.98–1.46) (63.1%).

Conclusions

This MES found that the history of diabetes mellitus was not associated with the risk of breast cancer in Asian women. As breast cancer in this population develops at a younger age, additional cohort studies are necessary to conduct a subgroup analysis by menopausal status at diagnosis of breast cancer in Asian women.

Investigation of the association between metabolic syndrome and breast cancer patients

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

Using Phosphatidylinositol Phosphorylation as Markers for Hyperglycemic Related Breast Cancer

Studies have suggested that type 2 diabetes (T2D) is associated with a higher incidence of breast cancer and related mortality rates. T2D postmenopausal women have an ~20% increased chance of developing breast cancer, and women with T2D and breast cancer have a 50% increase in mortality compared to breast cancer patients without diabetes. This correlation has been attributed to the general activation of insulin receptor signaling, glucose metabolism, phosphatidylinositol (PI) kinases, and growth pathways. Furthermore, the presence of breast cancer specific PI kinase and/or phosphatase mutations enhance metastatic breast cancer phenotypes. We hypothesized that each of the breast cancer subtypes may have characteristic PI phosphorylation profiles that are changed in T2D conditions. Therefore, we sought to characterize the PI phosphorylation when equilibrated in normal glycemic versus hyperglycemic serum conditions. Our results suggest that hyperglycemia leads to: 1) A reduction in PI3P and PIP3, with increased PI4P that is later converted to PI(3,4)P2 at the cell surface in hormone receptor positive breast cancer; 2) a reduction in PI3P and PI4P with increased PIP3 surface expression in human epidermal growth factor receptor 2-positive (HER2+) breast cancer; and 3) an increase in di- and tri-phosphorylated PIs due to turnover of PI3P in triple negative breast cancer. This study begins to describe some of the crucial changes in PIs that play a role in T2D related breast cancer incidence and metastasis.

<p>Glycosylated Hemoglobin A1c Is Associated with Anthropometric Measurements and Tumor Characteristics in Breast Cancer Patients</p>

Purpose

To investigate the association between glycosylated hemoglobin A1c (HbA1c) with anthropometric measurements and clinicopathologic characteristics of breast cancer patients. Such data are lacking in Arabian countries.

Patients and Methods

A cross-sectional study was conducted at the Outpatient Oncology Unit at King Hussein Medical Center at the Royal Medical Services (RMS) and 223 breast cancer patients were included. Blood levels of HbA1c were measured and patients were classified into normal/non-diabetic (HbA1c <5.7%), prediabetic (HbA1c 5.7–6.4%), and diabetic (HbA1c ≥6.5%).

Results

The average age of patients was 49.9±10.3 years. Most patients had waist circumference equal to or more than 80 cm (91.9%) and more than half (55.2%) had waist-hip ratio equal to or more than 0.85. Mean body mass index (BMI) was 29.9±5.7 kg/m². The mean level of HbA1c was 6.2±1.4% (range 4.7% to 12.6%). HbA1c levels revealed that most patients in this study classified as prediabetics (44.4%). There was a significant positive correlation between HbA1c levels and each of patient's age (r=0.267, p<0.001), waist circumference (r=0.180, p=0.008), and waist-hip ratio (r=0.278, p<0.001). Compared with premenopausal breast cancer patients, postmenopausal patients had significantly higher HbA1c blood levels (t=–3.542, p=0.003). HbA1c was significantly associated with stage (p=0.044) and grade (p=0.016) of carcinoma in premenopausal breast cancer patients. Among postmenopausal cases, HbA1c was significantly associated with molecular subtype of the disease (p=0.039).

Conclusion

The majority of Jordanian breast cancer patients in this study are prediabetic, obese, and had visceral obesity. HbA1c levels are increased among older patients and those who have greater waist circumference and waist-hip ratio. HbA1c is associated with advanced stage and grade of breast carcinoma in premenopausal patients and with molecular subtype in postmenopausal cases. These findings urge the need to screen breast cancer patients for glycemic status upon disease presentation and to further consider treatments to control hyperglycemia in order to reduce the impact of metabolic derangements on disease prognosis and outcomes.

Diabetes and Sarcopenic Obesity: Pathogenesis, Diagnosis, and Treatments

Sarcopenic obesity and diabetes are two increasing health problems worldwide, which both share many common risk factors, such as aging, and general obesity. The pathogenesis of sarcopenic obesity includes aging, physical inactivity, malnutrition, low-grade inflammation, insulin resistance, and hormonal changes. Nevertheless, there are two major reasons to cause diabetes: impaired insulin secretion and impaired insulin action. Furthermore, the individual diagnosis of obesity and sarcopenia should be combined to adequately define sarcopenic obesity. Also, the diagnosis of diabetes includes fasting plasma glucose test (FPG), 2-h oral glucose tolerance test (OGTT), glycated hemoglobin (A1C), and random plasma glucose coupled with symptoms. Healthy diet and physical activity are beneficial to both sarcopenic obesity and diabetes, but there are only recommended drugs for diabetes. This review consolidates and discusses the latest research in pathogenesis, diagnosis, and treatments of diabetes and sarcopenic obesity.

The Metabolic Syndrome Is a Risk Factor for Breast Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

The metabolic syndrome (MetS) has been associated with the pathogenesis and prognosis of various malignant tumors. In this systematic review and meta-analysis, we explored the relationship between MetS and breast cancer (BC).

METHODS

Relevant studies were systematically searched on Ovid MEDLINE, Embase, Cochrane database, and PubMed up to September 16, 2019, using "breast cancer" and "metabolic syndrome" as keywords. Eligible studies with clear definition of MetS, available data, and relationships between MetS and BC were evaluated using a risk ratio (RR) and its 95% confidence interval (CI).

RESULTS

Twenty-five studies, including 13 cohort studies and 12 case-control studies, met the inclusion criteria, which assessed a total of 392,583 female participants and 19,628 BC patients. The results revealed a statistically significant increase by 52% of the risk of BC in adult females with MetS (RR = 1.49, 95% CI = 1.31-1.70, p < 0.0001). Postmenopausal MetS patients may have a twofold risk to suffer BC (RR = 2.01, 95% CI = 1.55-2.60, p < 0.001). The risk of BC increased markedly with the number of MetS components: RR = 1.00 for 1 component (p = 0.976), RR = 1.40 for 2 components (p = 0.121), and RR = 1.98 for >3 components (p < 0.001). The risk factors associated with BC were obesity, hypertension, and diabetes (RR = 1.33, 1.19, and 1.30 respectively, all p < 0.001).

CONCLUSIONS

Our study demonstrated that MetS is highly related with BC. In postmenopausal patients with ≥2 MetS components or a combination of obesity, hypertension, and diabetes, routine BC screening could help to detect BC at an early stage.

Metformin: The Answer to Cancer in a Flower? Current Knowledge and Future Prospects of Metformin as an Anti-Cancer Agent in Breast Cancer

Interest has grown in studying the possible use of well-known anti-diabetic drugs as anti-cancer agents individually or in combination with, frequently used, chemotherapeutic agents and/or radiation, owing to the fact that diabetes heightens the risk, incidence, and rapid progression of cancers, including breast cancer, in an individual. In this regard, metformin (1, 1-dimethylbiguanide), well known as 'Glucophage' among diabetics, was reported to be cancer preventive while also being a potent anti-proliferative and anti-cancer agent. While meta-analysis studies reported a lower risk and incidence of breast cancer among diabetic individuals on a metformin treatment regimen, several in vitro, pre-clinical, and clinical studies reported the efficacy of using metformin individually as an anti-cancer/anti-tumor agent or in combination with chemotherapeutic drugs or radiation in the treatment of different forms of breast cancer. However, unanswered questions remain with regards to areas such as cancer treatment specific therapeutic dosing of metformin, specificity to cancer cells at high concentrations, resistance to metformin therapy, efficacy of combinatory therapeutic approaches, post-therapeutic relapse of the disease, and efficacy in cancer prevention in non-diabetic individuals. In the current article, we discuss the biology of metformin and its molecular mechanism of action, the existing cellular, pre-clinical, and clinical studies that have tested the anti-tumor potential of metformin as a potential anti-cancer/anti-tumor agent in breast cancer therapy, and outline the future prospects and directions for a better understanding and re-purposing of metformin as an anti-cancer drug in the treatment of breast cancer.