Pre-diagnosis blood glucose and prognosis in women with breast cancer

Glutamate Transport Proteins and Metabolic Enzymes are Poor Prognostic Factors in Invasive Lobular Carcinoma

Invasive Lobular Carcinoma (ILC) is a subtype of breast cancer characterized by distinct biological features, and limited glucose uptake coupled with increased reliance on amino acid and lipid metabolism. Our prior studies highlight the importance of glutamate as a key regulator of ILC tumor growth and therapeutic response. Here we examine the expression of four key proteins involved in glutamate transport and metabolism - SLC3A2, SLC7A11, GPX4, and GLUD1/2 - in a racially diverse cohort of 72 estrogen receptor-positive (ER+) ILC and 50 ER+ invasive ductal carcinoma, no special type (IDC/NST) patients with primary disease. All four proteins are associated with increased tumor size in ILC, but not IDC/NST, with SLC3A2 also specifically linked to shorter overall survival and the presence of comorbidities in ILC. Notably, GLUD1/2 expression is associated with ER expression in ILC, and is most strongly associated with increased tumor size and stage in Black women with ILC from our cohort and TCGA. We further explore the effects of GLUD1 inhibition in endocrine therapy-resistant ILC cells using the small-molecule inhibitor R162, which reduces ER protein levels, increases reactive oxygen species, and inhibits oxidative phosphorylation. These findings highlight a potentially important role for glutamate metabolism in ILC, particularly for Black women, and position several of these glutamate-handling proteins as potential targets for therapeutic intervention in ILC.

De Ritis ratio in elderly glioblastoma patients treated with chemoradiation: A comprehensive analysis of serum biomarkers

Background

We aimed to comprehensively investigate the prognostic value of pretreatment laboratory parameters in elderly patients with glioblastoma treated with temozolomide (TMZ)-based chemoradiation.

Methods

Patients aged ≥ 65 years from 4 institutions with newly diagnosed IDH-wild-type glioblastoma who received radiotherapy (RT) with concurrent TMZ between 2006 and 2021 were included. Patient factors (age, Karnofsky performance status (KPS), temporalis muscle thickness), molecular factors (MGMT promoter methylation, EGFR amplification, TERT promoter mutation, and TP53 mutation status), treatment factors (extent of resection, and RT dose), and pretreatment laboratory parameters (serum De Ritis ratio, glucose level, neutrophil-to-lymphocyte ratio, platelet count, and systemic immune-inflammation index) were included in the analysis. The primary endpoint was overall survival (OS).

Results

In total, 490 patients were included in the analysis. The median follow-up period was 12.3 months (range, 1.6-149.9 months). Median OS was significantly prolonged in patients with De Ritis ratio < 1.2 (18.2 vs 15.3 months, P = .022) and in patients with glucose level < 150 mg/dL (18.7 vs 16.5 months, P = .034) per univariate analysis. In multivariate analysis, KPS ≥ 70, MGMT promoter methylation, extent of resection greater than partial resection, De Ritis ratio < 1.2, and glucose level < 150 mg/dL were significant prognostic factors for improved OS.

Conclusions

Along with well-known prognostic factors, pre-RT serum biomarkers, including the De Ritis ratio and glucose level, also had prognostic value in elderly patients with glioblastoma treated with TMZ-based chemoradiation.

Obesity Associated with Prediabetes Increases the Risk of Breast Cancer Development and Progression-A Study on an Obese Rat Model with Impaired Glucose Tolerance

Patients with comorbidities of obesity and diabetes are recognized to be at high risk of breast cancer development and face worse breast cancer outcomes. Though several reports showed the reinforced link between obesity, diabetes, and prediabetes with breast cancer, the underlying molecular mechanisms are still unknown. The present study aimed to investigate the underlying molecular link between increased risks of breast cancer due to coincident diabetes or obesity using a spontaneous obese rat model with impaired glucose tolerance (WNIN/GR-Ob rat). A single dose of solubilized DMBA suspension (40 mg/kg body weight) was orally administered to the animals at the age of 60 days to induce breast tumors. The tumor incidence, latency period, tumor frequency, and tumor volume were measured. Histology, immunohistochemistry, and immunoblotting were performed to evaluate the tumor morphology and expression levels of signal molecules. The development of mammary tumors in GR-Ob rats was characterized by early onset and shorter latency periods compared to control lean rats. While 62% of obese rats developed breast tumors, tumor development in lean rats was only 21%. Overexpression of ER, PR, Ki67, and p53 markers was observed in tumor tissues of obese rats in comparison with lean rats. The levels of the hallmarks of cell proliferation and angiogenesis involved in IGF-1/PI3K/Akt/GSK3β/β-catenin signaling pathway molecules were upregulated in obese rat breast tumors compared to lean rats. Furthermore, obesity with prediabetes is associated with changes in IGF-1 signaling and acts on PI3K/Akt/GSK3β/β-catenin signaling, which results in rapid cell proliferation and development of breast tumors in obese rats than the lean rats. These results indicate that tumor onset and development were faster in spontaneous obese rat models with impaired glucose tolerance than in their lean counterparts.

Metabolic abnormalities and survival among patients with non-metastatic breast cancer

BACKGROUND

Research on the impact of metabolic abnormalities on breast cancer prognosis is limited by small samples and assessment of laboratory values at a single time point, often prior to cancer diagnosis and treatment. In this population-based cohort, time-updated laboratory values were adjusted for cancer treatment to assess the association between metabolic risk factors (glucose, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides) and breast cancer survival.

METHODS

13,434 women diagnosed with stage I-III breast cancer from 2005-15 at Kaiser Permanente were included. All outpatient fasting glucose, HDL-C, LDL-C, and triglyceride values from diagnosis through 2019 or death were extracted from electronic medical records. Risk of breast cancer-specific mortality was evaluated with Cox proportional hazards models adjusted for metabolic labs, demographics, body mass index, diabetes, dyslipidemia and anti-hypertensive medications, tumor characteristics (stage, ER and HER2 receptor status) and cancer treatment (use of chemotherapy, tamoxifen, and aromatase inhibitors).

RESULTS

Mean (SD) age at diagnosis was 62.3 (11.8) years. Over a median follow-up of 8.6 years, 2,876 patients died; 1,080 of breast cancer. Patients with low HDL-C (≤ 45 vs. > 45 mg/dL) had higher breast cancer-specific mortality (HR, 1.77; 95% CI, 1.53-2.05), as did those with elevated fasting glucose (> 99 vs. 60-99 mg/dL) (HR, 1.19; 95% CI, 1.03-1.37). Elevated levels of triglycerides and LDL-C were not associated with breast cancer-specific mortality.

CONCLUSIONS

High fasting glucose and low HDL-C evaluated over time after cancer diagnosis were associated with higher breast cancer mortality independent of cancer treatments and changes in other metabolic risk factors. Future studies should address whether pharmacologic or lifestyle treatment of glucose and lipids after breast cancer diagnosis can optimize survival outcomes.

Circulating metabolites in the early stage of breast cancer were not related to cancer stage or subtypes but associated with ki67 level. Promising statistical discrimination from controls

It was documented that the presence of malignancy in an organism causes metabolomic alterations in blood plasma which applies also to breast cancer. Breast cancer is a heterogeneous disease and there are only limited known relations of plasma metabolomic signatures with the tumour characteristics in early BC and knowing them would be of great advantage in noninvasive diagnostics. In this study, we focused on the metabolic alterations in early BC in blood plasma with the aim to identify metabolomic characteristics of BC subtypes. We used 50 early BC patients (FIGO stage I and II), where no additional metabolomic changes from metastatically changed remote organs were to be expected. We compared plasma levels of metabolites against controls and among various molecular and histological BC subtypes. BC patients showed decreased plasma levels of branched-chain amino acids BCAAs (and related keto-acids), histidine pyruvate and alanine balanced with an increased level of 3-hydroxybutyrate. The levels of circulating metabolites were not related to BC molecular subtypes (luminal A/luminal B), histological finding or grade, eventually stage, which indicate that in early BC, the BC patients share common metabolomics fingerprint in blood plasma independent of grade, stage or molecular subtype of BC. We observed statistically significant correlations between tumour proliferation marker Ki-67 level and circulating metabolites: alanine, citrate, tyrosine, glutamine, histidine and proline. This may point out the metabolites those levels could be associated with tumour growth, and conversely, the rate of tumour proliferation could be potentially estimated from plasma metabolites. When analyzing metabolomic changes in BC, we concluded that some of them could be associated with the metabolomic features of cancer cells, but the other observed alterations in blood plasma are the results of the complex mutual biochemical pathways in the comprehensive inter-organ metabolic exchange and communication. In the end, statistical discrimination against controls performed with AUC >0.91 showed the very promising potential of plasma metabolomics in the search for biomarkers for oncologic diseases.

Association of hypertension, hyperlipidemia, obesity, and demographic risk factors with breast cancer in Bangladeshi women

In recent years, breast cancer incidences and related deaths have been rising among Bangladeshi women and will be a major threat by 2040. So, conducting more population-based studies is crucial. This case-control study was designed to quantitatively evaluate potential risk factors for breast cancer. In this population-based case-control study, 52 random breast cancer cases and 59 matched healthy controls, aged between 25 and 70 years, were included. The breast cancer patient samples were collected from the National Institute of Cancer Research and Hospital (NICRH), Dhaka, Bangladesh, from December 2021 to February 2022. The study was conducted fully following the Declaration of Helsinki guidelines. The collected socio-demographic data and blood samples of the study participants were analyzed. Chi-square analysis was used to compare study characteristics between cases and controls, Odds ratios (ORs) with 95% confidence intervals (CIs) were derived by univariate-logistic regression, and models were adjusted where necessary for study characteristics. Summary demographic characteristics of the 111 study participants suggested that higher age: (≥45): [OR 4.38, 95% CI (1.94-9.89), P value <.001], height: (<1.5 m): [OR 3.01, 95% CI (1.12-8.12), P value .029], low-incomes: [OR 6.83, 95% CI (2.11-22.05), P value .001], and illiteracy: [OR 12.65, 95% CI (3.49-45.79), P value .0001] showed significant correlations with breast cancer. The patient's body mass index (BMI) (≥30) indicated an association with breast cancer: [OR 3.91, 95% CI (1.00-15.31), P value .05]. The lipid profile: [triglycerides (TG): OR = 3.20, 95% CI (1.36-7.53), P value .008; TG/high-density lipid (HDL): OR = 8.82, 95% CI (2.81-27.68), P value <.001; and a lowered HDL: OR = 3.32, 95% CI (1.38-7.98), P value .007], hypertension: [systolic: OR 4.32, 95% CI (1.71-10.93), P value .002; and diastolic: OR 7.32, 95% CI (2.51-21.34), P value <.001], and gastric issues: [OR 6.07, 95% CI (2.00-18.37), P value .001], all showed significant association with breast cancer. The ER- breast cancer subtype was significantly associated with the overweight (OW) group (P value .046) whereas the PR-patients were significantly higher in the normal BMI group (P value .013). Results from this study might aid in the prevention, management, and raising of awareness against the specific risk factors among Bangladeshi women in near future.

Intermittent fasting during adjuvant chemotherapy may promote differential stress resistance in breast cancer patients

Background

Preclinical studies prove that short-term fasting secures healthy cells against chemotherapy side effects and makes malignant cells more vulnerable to them. This study aimed to examine the effects of intermittent fasting (IF) during adjuvant chemotherapy AC (doxorubicin, cyclophosphamide) protocol in breast cancer (BC) patients.

Methods

Forty-eight newly diagnosed human epidermal growth factor receptor 2-negative (HER2 negative) BC patients were divided equally into two groups (24 each). The first group was recruited to fast intermittently for three consecutive days around chemotherapy for 18 h a day from 12 am to 6 pm and eats through 6 h a day from 6 pm to 12 am with permission of drinking water during fasting hours (IF group). This IF was repeated every 3 weeks for four cycles. The second group is a non-fasting (NF) group that was allowed to eat regularly. Toxicity in the two groups was compared. Hematologic, metabolic, and inflammatory parameters were measured and compared.

Results

Toxicity related to the gastrointestinal tract (GIT) was reduced in the IF group. Hematologic parameters showed no significant variations between the two studied groups after cycle 4. There was a significant increase in median glucose and median insulin levels (P < 0.001 and P = 0.001, respectively) in the NF group between baseline and after cycle 4. In addition, there was a significant decrease in the median insulin level (P = 0.002) in the IF group between the two time points.

Conclusion

IF throughout chemotherapy was well tolerated and decreased the toxicity of chemotherapy. Additionally, IF-improved metabolic profiles of patients may have a positive impact on the clinical efficacy of chemotherapy.

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.

Sugar-Sweetened Soda Consumption and Total and Breast Cancer Mortality: The Western New York Exposures and Breast Cancer (WEB) Study

BACKGROUND

There is growing evidence of an association between sugar-sweetened beverages (SSB) and increased risk of mortality in various populations. However, SSB influence on mortality among patients with breast cancer is unknown.

METHODS

We assessed the relationship between sugar-sweetened soda and both all-cause and breast cancer mortality among women with incident, invasive breast cancer from the Western New York Exposures and Breast Cancer Study. Breast cancer cases were followed for a median of 18.7 years, with ascertainment of vital status via the National Death Index. Frequency of sugar-sweetened soda consumption was determined via dietary recall using a food frequency questionnaire. Cox proportional hazards, adjusting for relevant variables, were used to estimate HRs and 95% confidence intervals (CI).

RESULTS

Of the 927 breast cancer cases, 386 (54.7%) had died by the end of follow-up. Compared with never/rarely sugar-sweetened soda drinkers, consumption at ≥5 times per week was associated with increased risk of both total (HR = 1.62; 95% CI, 1.16-2.26; P _trend < 0.01) and breast cancer mortality (HR = 1.85; 95% CI, 1.16-2.94; P _trend < 0.01). Risk of mortality was similarly increased among ER-positive, but not ER-negative patients; among women with body mass index above the median, but not below the median; and among premenopausal, but not postmenopausal women for total mortality only.

CONCLUSIONS

Reported higher frequency of sugar-sweetened soda intake was associated with increased risks of both total and breast cancer mortality among patients with breast cancer.

IMPACT

These results support existing guidelines on reducing consumption of SSB, including for women with a diagnosis of breast cancer.

Predictive Factors Among Clinicopathological Characteristics for Sentinel Lymph Node Metastasis in T1-T2 Breast Cancer

BACKGROUND

The axillary lymph node status is an important prognostic factor of breast cancer. This study explores the predictive factors for sentinel lymph node (SLN) metastasis among the preoperative clinicopathological features, including impaired glucose tolerance (IGT).

METHODS

This study comprised patients diagnosed with breast cancer who underwent surgery at Nagasaki Harbor Medical Center between April 2014 and December 2019. The factors assessed using univariate and multivariate analyses were the clinicopathological data of these cancers, including the patient age, gender, menstrual status, breast or ovarian cancer family history, body mass index, glycosylated hemoglobin, clinical tumor size, nipple-tumor distance (NTD), tumor histology, histological grade, node status, estrogen receptor, progesterone receptor, human epidermal growth factor receptor type 2 status, and Ki67 labeling index.

RESULTS

In the cohort of 313 cases, the ratio of SLN metastasis was 17.3%. A univariate analysis found that the tumor size, NTD, IGT, and clinical tumor stage were associated with SLN metastasis. In a multivariable analysis, the tumor size, NTD, and IGT were associated with SLN metastasis. The receiver operating characteristic curve showed a sensitivity and specificity of 61.1% and 65.6%, respectively, at a cut-off of 1.7 cm for the tumor size (area under the curve [AUC]: 0.664; 95% confidence interval: 0.592-0.736), and a sensitivity and specificity of 60.4% and 62.9%, respectively, at a cut-off of 2.0 cm for NTD (AUC: 0.651; 95% confidence interval: 0.571-0.731) to predict the risk of SLN metastasis.

CONCLUSION

T1 and T2 breast cancer patients with a larger tumor size, tumor located closer to the nipple, and IGT have a higher risk of SLN metastases than others.

Blood glucose levels should be considered as a new vital sign indicative of prognosis during hospitalization

BACKGROUND AND AIMS

The measurement of vital signs is an important part of clinical work up. Presently, measurement of blood glucose is a factor for concern mostly when treating individuals with diabetes. Significance of blood glucose measurement in prognosis of non-diabetic and hospitalized patients is not clear.

METHODS

A systematic search of literature published in the Electronic databases, PubMed and Google Scholar was performed using following keywords; blood glucose, hospital admissions, critical illness, hospitalizations, cardiovascular disease (CVD), morbidity, and mortality. This literature search was largely restricted to non-diabetic individuals.

RESULTS

Blood glucose level, even when in high normal range, or in slightly high range, is an important determinant of morbidity and mortality, especially in hospitalized patients. Further, even slight elevation of blood glucose may increase mortality in patients with COVID-19. Finally, blood glucose variability and hypoglycemia in critically ill individuals without diabetes causes excess in-hospital complications and mortality.

CONCLUSION

In view of these data, we emphasize the significance of blood glucose measurement in all patients admitted to the hospital regardless of presence of diabetes. We propose that blood glucose be included as the "fifth vital sign" for any hospitalized patient.

Endocrinopathies and cancer cachexia

PURPOSE OF REVIEW

Cancer cachexia cannot be easily reversed by standard nutritional support and interventions directed at underlying metabolic derangements may be needed to prevent or reverse cachexia and maintain healthy body composition. The following review will highlight the contribution and potential therapeutic interventions for insulin resistance, alterations in ghrelin signaling, and hypogonadism in cancer patients.

RECENT FINDINGS

In addition to decreased caloric intake, chronic inflammation, and altered metabolism of glucose, proteins and lipids, endocrine abnormalities can propagate weight loss or changes in body composition in cancer patients.

SUMMARY

Cancer cachexia, loss of muscle mass with or without the loss of fat mass, is a multifactorial syndrome, which is associated with increased morbidity and mortality. Currently, limited therapeutic options for the treatment of weight loss in cancer patients exist, which lead to clinically meaningful improvements in weight gain and performance status. Treatment directed at underlying insulin resistance, low testosterone, and altered ghrelin sensitivity, in the future, may lead to potential therapeutic options for loss of lean body mass and cancer cachexia.

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.

Hyperglycemia Associated Metabolic and Molecular Alterations in Cancer Risk, Progression, Treatment, and Mortality

Cancer and diabetes are amongst the leading causes of deaths worldwide. There is an alarming rise in cancer incidences and mortality, with approximately 18.1 million new cases and 9.6 million deaths in 2018. A major contributory but neglected factor for risk of neoplastic transformation is hyperglycemia. Epidemiologically too, lifestyle patterns resulting in high blood glucose level, with or without the role of insulin, are more often correlated with cancer risk, progression, and mortality. The two conditions recurrently exist in comorbidity, and their interplay has rendered treatment regimens more challenging by restricting the choice of drugs, affecting surgical consequences, and having associated fatal complications. Limited comprehensive literature is available on their correlation, and a lack of clarity in understanding in such comorbid conditions contributes to higher mortality rates. Hence, a critical analysis of the elements responsible for enhanced mortality due to hyperglycemia-cancer concomitance is warranted. Given the lifestyle changes in the human population, increasing metabolic disorders, and glucose addiction of cancer cells, hyperglycemia related complications in cancer underline the necessity for further in-depth investigations. This review, therefore, attempts to shed light upon hyperglycemia associated factors in the risk, progression, mortality, and treatment of cancer to highlight important mechanisms and potential therapeutic targets.

p63 and SOX2 Dictate Glucose Reliance and Metabolic Vulnerabilities in Squamous Cell Carcinomas

Squamous cell carcinoma (SCC), a malignancy arising across multiple anatomical sites, is responsible for significant cancer mortality due to insufficient therapeutic options. Here, we identify exceptional glucose reliance among SCCs dictated by hyperactive GLUT1-mediated glucose influx. Mechanistically, squamous lineage transcription factors p63 and SOX2 transactivate the intronic enhancer cluster of SLC2A1. Elevated glucose influx fuels generation of NADPH and GSH, thereby heightening the anti-oxidative capacity in SCC tumors. Systemic glucose restriction by ketogenic diet and inhibiting renal glucose reabsorption with SGLT2 inhibitor precipitate intratumoral oxidative stress and tumor growth inhibition. Furthermore, reduction of blood glucose lowers blood insulin levels, which suppresses PI3K/AKT signaling in SCC cells. Clinically, we demonstrate a robust correlation between blood glucose concentration and worse survival among SCC patients. Collectively, this study identifies the exceptional glucose reliance of SCC and suggests its candidacy as a highly vulnerable cancer type to be targeted by systemic glucose restriction.

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.

Beta-hydroxybutyrate (3-OHB) can influence the energetic phenotype of breast cancer cells, but does not impact their proliferation and the response to chemotherapy or radiation

Background

Ketogenic diets (KDs) or short-term fasting are popular trends amongst supportive approaches for cancer patients. Beta-hydroxybutyrate (3-OHB) is the main physiological ketone body, whose concentration can reach plasma levels of 2–6 mM during KDs or fasting. The impact of 3-OHB on the biology of tumor cells described so far is contradictory. Therefore, we investigated the effect of a physiological concentration of 3 mM 3-OHB on metabolism, proliferation, and viability of breast cancer (BC) cells in vitro.

Methods

Seven different human BC cell lines (BT20, BT474, HBL100, MCF-7, MDA-MB 231, MDA-MB 468, and T47D) were cultured in medium with 5 mM glucose in the presence of 3 mM 3-OHB at mild hypoxia (5% oxygen) or normoxia (21% oxygen). Metabolic profiling was performed by quantification of the turnover of glucose, lactate, and 3-OHB and by Seahorse metabolic flux analysis. Expression of key enzymes of ketolysis as well as the main monocarboxylic acid transporter MCT2 and the glucose-transporter GLUT1 was analyzed by RT-qPCR and Western blotting. The effect of 3-OHB on short- and long-term cell proliferation as well as chemo- and radiosensitivity were also analyzed.

Results

3-OHB significantly changed the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) in BT20 cells resulting in a more oxidative energetic phenotype. MCF-7 and MDA-MB 468 cells had increased ECAR only in response to 3-OHB, while the other three cell types remained uninfluenced. All cells expressed MCT2 and GLUT1, thus being able to uptake the metabolites. The consumption of 3-OHB was not strongly linked to mRNA overexpression of key enzymes of ketolysis and did not correlate with lactate production and glucose consumption. Neither 3-OHB nor acetoacetate did interfere with proliferation. Further, 3-OHB incubation did not modify the response of the tested BC cell lines to chemotherapy or radiation.

Conclusions

We found that a physiological level of 3-OHB can change the energetic profile of some BC cell lines. However, 3-OHB failed to influence different biologic processes in these cells, e.g., cell proliferation and the response to common breast cancer chemotherapy and radiotherapy. Thus, we have no evidence that 3-OHB generally influences the biology of breast cancer cells in vitro.

Electronic supplementary material

The online version of this article (10.1186/s40170-018-0180-9) contains supplementary material, which is available to authorized users.

Beneficial effects of ketogenic diets for cancer patients: a realist review with focus on evidence and confirmation

Ketogenic diets (KDs) have gained popularity among patients and researchers alike due to their putative anti-tumor mechanisms. However, the question remains which conclusions can be drawn from the available human data thus far concerning the safety and efficacy of KDs for cancer patients. A realist review utilizing a matrix analytical approach was conducted according to the RAMESES publication standards. All available human studies were systematically analyzed and supplemented with results from animal studies. Evidence and confirmation were treated as separate concepts. In total, 29 animal and 24 human studies were included in the analysis. The majority of animal studies (72%) yielded evidence for an anti-tumor effect of KDs. Evidential support for such effects in humans was weak and limited to individual cases, but a probabilistic argument shows that the available data strengthen the belief in the anti-tumor effect hypothesis at least for some individuals. Evidence for pro-tumor effects was lacking completely. Feasibility of KDs for cancer patients has been shown in various contexts. The probability of achieving an anti-tumor effect seems greater than that of causing serious side effects when offering KDs to cancer patients. Future controlled trials would provide stronger evidence for or against the anti-tumor effect hypothesis.