The association between metabolic health, obesity phenotype and the risk of breast cancer

Exosomes isolated from metabolically unhealthy normal weight and overweight phenotypes deteriorate the ER/PR positive breast cancer behavior

Purpose

Obesity has been linked to a higher risk of postmenopausal breast cancer Yet, research indicates an opposite correlation between obesity and premenopausal breast cancer risk. Various obesity phenotypes based on metabolic health could play a significant part. This study aims to assess how plasma exosomes taken from women with varying obesity phenotypes impact MCF-7 cell migration, matrix metalloproteinase-2 activity, and apoptosis.

Methods

The characterization of isolated exosomes and their internalization into MCF-7 cells was evaluated. The treatment of MCF-7 cells with exosomes isolated from different groups was done. Migration, the activity of MMP-2, mRNA expression of Bax and Bcl-2, protein expression of p-53 and Thr55 p-p53, and apoptosis were assessed.

Results

Isolated exosomes from unhealthy obese individuals increase MCF-7 cell migration. Regarding MMP activities, unhealthy normal weight and overweight and healthy obese groups isolated exosomes increase the MMP-2 activity than the treated group with exosomes isolated from counterpart groups. Furthermore, unhealthy normal weight and overweight and healthy obese obtained exosomes decrease apoptosis compared to counterpart groups.

Conclusion

Altogether, plasma exosomes derived from both unhealthy individuals with normal weight and overweight status, as well as those with unhealthy obesity, negatively impacted the behavior of estrogen/progesterone receptor-positive breast cancer cells.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01295-1.

Association of Fibroids, Endometriosis, and Gynecologic Surgeries with Breast Cancer Incidence and Hormone Receptor Subtypes

BACKGROUND

Fibroids and endometriosis are sex hormone-mediated and exhibit cancer-like behavior. Breast cancer may be more common in women who have had these conditions, but the literature is conflicting and does not always address factors like hysterectomy/oophorectomy status, race/ethnicity, menopause, and hormone receptor subtypes.

METHODS

Data are from the Sister Study, a cohort of 50,884 U.S. women enrolled in 2003 to 2009 and followed through 2020. Cox proportional hazards models with time-varying exposures and covariates assessed the relationship of fibroids or endometriosis with breast cancer. Logistic regression examined the association with estrogen receptor (ER) status among cases.

RESULTS

Fibroids (19,932 cases) were positively associated with breast cancer [fully adjusted HR: 1.07; 95% confidence interval (CI): 1.01-1.14], notably among Black participants (HR: 1.34; 95% CI: 1.07-1.69) and women who had a hysterectomy (HR: 1.18; 95% CI: 1.05-1.31). Endometriosis (3,970 cases) was not associated with breast cancer (HR: 0.99; 95% CI: 0.91-1.08). Among 4,419 breast cancer cases, fibroids were positively associated with ER+ subtypes (OR: 1.34; 95% CI: 1.10-1.65), while endometriosis was negatively associated with ER+ subtypes (OR: 0.78; 95% CI: 0.61-1.01).

CONCLUSIONS

We observed a modest positive association between fibroids and breast cancer, particularly ER+ breast cancer. No relationship with endometriosis and breast cancer incidence was found.

IMPACT

Fibroids, even in those with a family history of breast cancer, might modify breast cancer risk stratification tools. Future studies should further assess this link and interrogate shared risk factors.

Body mass index and altered lipid profile as major risk markers for breast cancer progression: a cross-sectional study of postmenopausal women in Pakistan

BACKGROUND

In Pakistan, the death rate for post-menopausal women with breast cancer is significant due to late detection and delayed referral to proper facilities. There are a few reports on Pakistan's epidemiology and breast cancer risk factors. There are modifiable and non-modifiable risk factors associated with the development of breast carcinoma; of which body mass index (BMI), central obesity, and lipid profile are considered as major risk markers.

METHODS

This was a cross-sectional analytical study. A total of 384 women constituted the present study sample. Purposive sampling was used to collect 192 confirmed new breast cancer cases throughout the study. By using basic random sampling, an equal number of controls were chosen. Studied parameters included age, fasting blood sugar, cholesterol, triglyceride, serum high-density lipoprotein, cholesterol, serum low-density lipoprotein cholesterol, weight, height, BMI, waist circumference, and waist-to-hip ratio. The inclusion criteria of this study were post-menopausal women (45-65 years) in Pakistan. The confirmation of breast carcinoma was done through histopathology. Breast cancer occurrence was taken as a dependent variable, whereas BMI, central obesity, and lipid profile were taken as independent variables.

RESULTS

Studied risk factors (cholesterol, BMI, and central obesity) significantly correlated with breast cancer. Cholesterol has a significantly high positive correlation (0.646) with breast cancer. BMI has a positive significant correlation (0.491) with breast cancer, and central obesity has a low but positive significant correlation (0.266) with breast cancer. Moreover, the binary logistic regression model also showed a significant association between biochemical factors and breast cancer occurrence. Regression analysis depicted a linear relationship between a dependent variable (breast cancer occurrence) and independent variables (central obesity, cholesterol, BMI).

CONCLUSION

Postmenopausal overweight (central obesity), increased BMI and high cholesterol levels are major risk factors for breast cancer. Moreover, high total cholesterol proved to be the most significant risk marker for the occurrence of breast cancer in post-menopausal women of Pakistan.

Association between Metabolically Healthy Status and Risk of Gastrointestinal Cancer

PURPOSE

Although obesity is associated with numerous diseases, the risks of disease may depend on metabolically healthy status. Nevertheless, it is unclear to whether metabolically healthy status affects risk of gastrointestinal (GI) cancer in general Chinese population.

MATERIALS AND METHODS

A total of 114,995 participants who met the criteria were included from the Kailuan Study. The study participants were divided into four groups according to body mass index (BMI)/waist circumference (WC) and metabolic status. Incident of GI cancer (esophageal cancer, gastric cancer, liver cancer, biliary cancer, pancreatic cancer, and colorectal cancer) during 2006-2020 were confirmed by review of medical records. The Cox proportional hazard regression models were used to assess the association metabolically healthy status with the risk of GI cancer by calculating the hazard ratios (HR) and 95% confidence interval (CI).

RESULTS

During a mean 13.76 years of follow-up, we documented 2,311 GI cancers. Multivariate Cox regression analysis showed that compared with the metabolically healthy normal-weight group, metabolically healthy obese (MHO) participants demonstrated an increased risk of developing GI cancer (HR, 1.54; 95% CI, 1.11 to 2.13) by BMI categories. However, such associations were not found for WC category. These associations were moderated by age, sex, and anatomical site of the tumor. Individuals with metabolic unhealthy normal-weight or metabolic unhealthy obesity phenotype also have an increased risk of GI cancer.

CONCLUSION

MHO phenotype was associated with increased risk of GI cancer. Moreover, individuals who complicated by metabolic unhealthy status have an increased risk of developing GI cancer. Hence, clinicians should consider the risk of incident GI cancer in people with abnormal metabolically healthy status and counsel them about metabolic fitness and weight control.

Metabolically healthy/unhealthy obesity and breast cancer: A possible role of plasma-derived extracellular vesicles on the cancerous behavior of triple-negative breast cancer

PURPOSE

Obesity has known detrimental effects on breast cancer (BC) development and progression. However, it's essential to consider the obesity phenotype based on metabolic health. This study aims to evaluate the impact of circulating extracellular vesicles (EVs) from women with metabolically healthy or unhealthy normal weight, overweight, and obesity on MDA-MB-231 cell migration, invasion, and apoptosis.

METHODS

Plasma EVs were isolated from different obesity phenotypes in women. EVs were characterized and EVs uptake by MDA-MB-231 cells was assessed. MDA-MB-231 cell lines were treated with EVs obtained from various studied groups, and migration, invasion, MMP-2 and MMP-9 activity, Bax and Bcl-2 mRNA expression, p-53 and Thr55 p-p53 protein expression, and apoptosis were assessed.

RESULTS

EVs from obese individuals, regardless of phenotype, increased invasion and MMP-2 activity compared to healthy normal-weight EVs. Normal-weight EVs led to higher invasion under unhealthy conditions. BC cell migration was enhanced by EVs from healthy obese individuals compared to healthy normal-weight EVs. EVs from unhealthy obese women exhibited significantly lower p53/p-p53 levels and reduced apoptosis compared to healthy obese groups.

CONCLUSION

It appears that EVs from both normal-weight women with unhealthy conditions and those with obesity or overweight, irrespective of metabolic status, worsened the cancerous behavior of TNBC cells. Therefore, considering metabolic health, in addition to BMI, is crucial for understanding obesity-related disorders.

Early life socioeconomic position contributes to adult obesity independent of adult socioeconomic factors: Findings from the sister study cohort

Low socioeconomic position (SEP) has been associated with obesity within life stages; however, life course SEP may also alter downstream obesity risk. Research is needed to understand the impact of childhood SEP, independent of adult SEP, as well as SEP trajectories over the life course on adult obesity risk. We use data from the Sister Study, a prospective U.S. cohort of women aged 35-74 years (N = 50,884; enrollment: 2003-2009). Relative risks (RR) for adult obesity associated with childhood SEP (latent variable) and five latent life course SEP profiles were estimated in overall and race and ethnicity-stratified log binomial regression models. We estimated the direct effect of childhood SEP on adult obesity and mediation by adult SEP. Lower childhood SEP was associated with greater obesity risk (RR = 1.16, 95% CI: 1.15-1.17). In stratified models, RRs were elevated across groups though lower for Black and Hispanic/Latina participants, despite greater prevalence of obesity among Black participants. The direct effect of childhood SEP on adult obesity persisted in mediation models independent of adult SEP (RR = 1.10, 95% CI: 1.08-1.12) with adult SEP mediating approximately 40% of the total effect of childhood SEP on adult obesity. Furthermore, adult obesity risk was elevated for all life course SEP profiles compared to persistent high advantage. Life course SEP profiles indicating greater advantage in adulthood than childhood were not associated with reduced adult obesity risk among those experiencing less than high advantage in childhood. In conclusion, lower childhood SEP, independent of adult SEP, may be an important risk factor for adult obesity.

The impact of poor metabolic health on aggressive breast cancer: adipose tissue and tumor metabolism

Obesity and type 2 diabetes are chronic metabolic diseases that impact tens to hundreds of millions of adults, especially in developed countries. Each condition is associated with an elevated risk of breast cancer and with a poor prognosis after treatment. The mechanisms connecting poor metabolic health to breast cancer are numerous and include hyperinsulinemia, inflammation, excess nutrient availability, and adipose tissue dysfunction. Here, we focus on adipose tissue, highlighting important roles for both adipocytes and fibroblasts in breast cancer progression. One potentially important mediator of adipose tissue effects on breast cancer is the fibroblast growth factor receptor (FGFR) signaling network. Among the many roles of FGFR signaling, we postulate that key mechanisms driving aggressive breast cancer include epithelial-to-mesenchymal transition and cellular metabolic reprogramming. We also pose existing questions that may help better understand breast cancer biology in people with obesity, type 2 diabetes, and poor metabolic health.

Unraveling the Role of Hepatic PGC1α in Breast Cancer Invasion: A New Target for Therapeutic Intervention?

Breast cancer (BC) is the most common cancer among women worldwide and the main cause of cancer deaths in women. Metabolic components are key risk factors for the development of non-alcoholic fatty liver disease (NAFLD), which may promote BC. Studies have reported that increasing PGC1α levels increases mitochondrial biogenesis, thereby increasing cell proliferation and metastasis. Moreover, the PGC1α/ERRα axis is a crucial regulator of cellular metabolism in various tissues, including BC. However, it remains unclear whether NAFLD is closely associated with the risk of BC. Therefore, the present study aimed to determine whether hepatic PGC1α promotes BC cell invasion via ERRα. Various assays, including ELISA, western blotting, and immunoprecipitation, have been employed to explore these mechanisms. According to the KM plot and TCGA data, elevated PGC1α expression was highly associated with a shorter overall survival time in patients with BC. High concentrations of palmitic acid (PA) promoted PGC1α expression, lipogenesis, and inflammatory processes in hepatocytes. Conditioned medium obtained from PA-treated hepatocytes significantly increased BC cell proliferation. Similarly, recombinant PGC1α in E0771 and MCF7 cells promoted cell proliferation, migration, and invasion in vitro. However, silencing PGC1α in both BC cell lines resulted in a decrease in this trend. As determined by immunoprecipitation assay, PCG1a interacted with ERRα, thereby facilitating the proliferation of BC cells. This outcome recognizes the importance of further investigations in exploring the full potential of hepatic PGC1α as a prognostic marker for BC development.

Menopause-Biology, consequences, supportive care, and therapeutic options

Menopause is the cessation of ovarian function, with loss of reproductive hormone production and irreversible loss of fertility. It is a natural part of reproductive aging. The physiology of the menopause is complex and incompletely understood. Globally, menopause occurs around the age of 49 years, with geographic and ethnic variation. The hormonal changes of the menopause transition may result in both symptoms and long-term systemic effects, predominantly adverse effects on cardiometabolic and musculoskeletal health. The most effective treatment for bothersome menopausal symptoms is evidence-based, menopausal hormone therapy (MHT), which reduces bone loss and may have cardiometabolic benefits. Evidence-based non-hormonal interventions are also available for symptom relief. Treatment should be individualized with shared decision-making. Most MHT regimens are not regulator approved for perimenopausal women. Studies that include perimenopausal women are needed to determine the efficacy and safety of treatment options. Further research is crucial to improve menopause care, along with research to guide policy and clinical practice.

FGF1 supports glycolytic metabolism through the estrogen receptor in endocrine-resistant and obesity-associated breast cancer

BACKGROUND

Obesity increases breast cancer risk and breast cancer-specific mortality, particularly for people with estrogen receptor (ER)-positive tumors. Body mass index (BMI) is used to define obesity, but it may not be the best predictor of breast cancer risk or prognosis on an individual level. Adult weight gain is an independent indicator of breast cancer risk. Our previous work described a murine model of obesity, ER-positive breast cancer, and weight gain and identified fibroblast growth factor receptor (FGFR) as a potential driver of tumor progression. During adipose tissue expansion, the FGF1 ligand is produced by hypertrophic adipocytes as a stimulus to stromal preadipocytes that proliferate and differentiate to provide additional lipid storage capacity. In breast adipose tissue, FGF1 production may stimulate cancer cell proliferation and tumor progression.

METHODS

We explored the effects of FGF1 on ER-positive endocrine-sensitive and resistant breast cancer and compared that to the effects of the canonical ER ligand, estradiol. We used untargeted proteomics, specific immunoblot assays, gene expression profiling, and functional metabolic assessments of breast cancer cells. The results were validated in tumors from obese mice and breast cancer datasets from women with obesity.

RESULTS

FGF1 stimulated ER phosphorylation independently of estradiol in cells that grow in obese female mice after estrogen deprivation treatment. Phospho- and total proteomic, genomic, and functional analyses of endocrine-sensitive and resistant breast cancer cells show that FGF1 promoted a cellular phenotype characterized by glycolytic metabolism. In endocrine-sensitive but not endocrine-resistant breast cancer cells, mitochondrial metabolism was also regulated by FGF1. Comparison of gene expression profiles indicated that tumors from women with obesity shared hallmarks with endocrine-resistant breast cancer cells.

CONCLUSIONS

Collectively, our data suggest that one mechanism by which obesity and weight gain promote breast cancer progression is through estrogen-independent ER activation and cancer cell metabolic reprogramming, partly driven by FGF/FGFR. The first-line treatment for many patients with ER-positive breast cancer is inhibition of estrogen synthesis using aromatase inhibitors. In women with obesity who are experiencing weight gain, locally produced FGF1 may activate ER to promote cancer cell metabolic reprogramming and tumor progression independently of estrogen.

A body shape index (ABSI) is associated inversely with post-menopausal progesterone-receptor-negative breast cancer risk in a large European cohort

BACKGROUND

Associations of body shape with breast cancer risk, independent of body size, are unclear because waist and hip circumferences are correlated strongly positively with body mass index (BMI).

METHODS

We evaluated body shape with the allometric "a body shape index" (ABSI) and hip index (HI), which compare waist and hip circumferences, correspondingly, among individuals with the same weight and height. We examined associations of ABSI, HI, and BMI (per one standard deviation increment) with breast cancer overall, and according to menopausal status at baseline, age at diagnosis, and oestrogen and progesterone receptor status (ER+/-PR+/-) in multivariable Cox proportional hazards models using data from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.

RESULTS

During a mean follow-up of 14.0 years, 9011 incident breast cancers were diagnosed among 218,276 women. Although there was little evidence for association of ABSI with breast cancer overall (hazard ratio HR = 0.984; 95% confidence interval: 0.961-1.007), we found borderline inverse associations for post-menopausal women (HR = 0.971; 0.942-1.000; n = 5268 cases) and breast cancers diagnosed at age ≥ 55 years (HR = 0.976; 0.951-1.002; n = 7043) and clear inverse associations for ER + PR- subtypes (HR = 0.894; 0.822-0.971; n = 726) and ER-PR- subtypes (HR = 0.906; 0.835-0.983 n = 759). There were no material associations with HI. BMI was associated strongly positively with breast cancer overall (HR = 1.074; 1.049-1.098), for post-menopausal women (HR = 1.117; 1.085-1.150), for cancers diagnosed at age ≥ 55 years (HR = 1.104; 1.076-1.132), and for ER + PR + subtypes (HR = 1.122; 1.080-1.165; n = 3101), but not for PR- subtypes.

CONCLUSIONS

In the EPIC cohort, abdominal obesity evaluated with ABSI was not associated with breast cancer risk overall but was associated inversely with the risk of post-menopausal PR- breast cancer. Our findings require validation in other cohorts and with a larger number of PR- breast cancer cases.

Metabolically defined body size and body shape phenotypes and risk of postmenopausal breast cancer in the European Prospective Investigation into Cancer and Nutrition

BACKGROUND

Excess body fatness and hyperinsulinemia are both associated with an increased risk of postmenopausal breast cancer. However, whether women with high body fatness but normal insulin levels or those with normal body fatness and high levels of insulin are at elevated risk of breast cancer is not known. We investigated the associations of metabolically defined body size and shape phenotypes with the risk of postmenopausal breast cancer in a nested case-control study within the European Prospective Investigation into Cancer and Nutrition.

METHODS

Concentrations of C-peptide-a marker for insulin secretion-were measured at inclusion prior to cancer diagnosis in serum from 610 incident postmenopausal breast cancer cases and 1130 matched controls. C-peptide concentrations among the control participants were used to define metabolically healthy (MH; in first tertile) and metabolically unhealthy (MU; >1st tertile) status. We created four metabolic health/body size phenotype categories by combining the metabolic health definitions with normal weight (NW; BMI < 25 kg/m2 , or WC < 80 cm, or WHR < 0.8) and overweight or obese (OW/OB; BMI ≥ 25 kg/m2 , or WC ≥ 80 cm, or WHR ≥ 0.8) status for each of the three anthropometric measures separately: (1) MHNW, (2) MHOW/OB, (3) MUNW, and (4) MUOW/OB. Conditional logistic regression was used to compute odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Women classified as MUOW/OB were at higher risk of postmenopausal breast cancer compared to MHNW women considering BMI (OR = 1.58, 95% CI = 1.14-2.19) and WC (OR = 1.51, 95% CI = 1.09-2.08) cut points and there was also a suggestive increased risk for the WHR (OR = 1.29, 95% CI = 0.94-1.77) definition. Conversely, women with the MHOW/OB and MUNW were not at statistically significant elevated risk of postmenopausal breast cancer risk compared to MHNW women.

CONCLUSION

These findings suggest that being overweight or obese and metabolically unhealthy raises risk of postmenopausal breast cancer while overweight or obese women with normal insulin levels are not at higher risk. Additional research should consider the combined utility of anthropometric measures with metabolic parameters in predicting breast cancer risk.

Changes in metabolic syndrome and the risk of breast and endometrial cancer according to menopause in Korean women

OBJECTIVES

This study investigated how changes in metabolic syndrome (MetS) are associated with the subsequent risk of breast and endometrial cancer according to menopausal status.

METHODS

This cohort study, using data from the National Health Insurance Service database, included women aged ≥40 years who underwent 2 biennial cancer screenings (2009-2010 and 2011-2012) and were followed up until 2020. Participants were grouped into MetS-free, MetS-recovery, MetS-development, and MetS-persistent groups. Menopausal status (premenopausal, perimenopausal, and postmenopausal) was assessed at 2 screenings. Cox proportional hazard regression was used to assess the association between MetS changes and cancer risk.

RESULTS

In 3,031,980 women, breast and endometrial cancers were detected in 39,184 and 4,298, respectively. Compared with the MetS-free group, those who recovered, developed, or had persistent MetS showed an increased risk of breast cancer, with adjusted hazard ratios (aHRs) of 1.05, 1.05, and 1.11, respectively (p<0.005). MetS persistence was associated with an increased risk of breast cancer in postmenopausal women (aHR, 1.12, 95% confidence interval [CI], 1.08 to 1.16) but not in premenopausal or perimenopausal women. MetS persistence was associated with an increased risk of endometrial cancer in premenopausal, perimenopausal, and postmenopausal women, with aHRs of 1.41 (95% CI, 1.17 to 1.70), 1.59 (95% CI, 1.19 to 2.12), and 1.47 (95% CI, 1.32 to 1.63), respectively.

CONCLUSIONS

Increased breast cancer risk was associated with recovered, developed, and persistent MetS in postmenopausal women. Meanwhile, increased endometrial cancer risk was found in obese women who recovered from MetS or persistently had MetS, regardless of menopausal status, when compared to MetS-free women.

Bidirectional Mendelian randomization study of insulin-related traits and risk of ovarian cancer

BACKGROUND

It is well known that the occurrence and development of ovarian cancer are closely related to the patient's weight and various endocrine factors in the body.

AIM

Mendelian randomization (MR) was used to analyze the bidirectional relationship between insulin related characteristics and ovarian cancer.

METHODS

The data on insulin related characteristics are from up to 5567 diabetes free patients from 10 studies, mainly including fasting insulin level, insulin secretion rate, peak insulin response, etc. For ovarian cancer, UK Biobank data just updated in 2021 was selected, of which the relevant gene data was from 199741 Europeans. Mendelian randomization method was selected, with inverse variance weighting (IVW) as the main estimation, while MR Pleiotropy, MR Egger, weighted median and other methods were used to detect the heterogeneity of data and whether there was multi validity affecting conclusions.

RESULTS

Among all insulin related indicators (fasting insulin level, insulin secretion rate, peak insulin response), the insulin secretion rate was selected to have a causal relationship with the occurrence of ovarian cancer (IVW, P < 0.05), that is, the risk of ovarian cancer increased with the decrease of insulin secretion rate. At the same time, we tested the heterogeneity and polymorphism of this indicator, and the results were non-existent, which ensured the accuracy of the analysis results. Reverse causal analysis showed that there was no causal effect between the two (P>0.05).

CONCLUSION

The impairment of the insulin secretion rate has a causal effect on the risk of ovarian cancer, which was confirmed by Mendel randomization. This suggests that the human glucose metabolism cycle represented by insulin secretion plays an important role in the pathogenesis of ovarian cancer, which provides a new idea for preventing the release of ovarian cancer.

Association between different metabolic phenotypes of obesity and thyroid disorders among Chinese adults: a nationwide cross-sectional study

Background

Increased body mass index (BMI) and metabolic abnormalities both have potential associations with thyroid disease. The aim of this study was to investigate the correlation between different metabolic phenotypes of obesity and thyroid disorders using nationwide data from China.

Methods

Data were collected from a cross-sectional survey called the Thyroid Disorders, Iodine Status, and Diabetes Epidemiological Survey conducted between 2015 and 2017 in China. A total of 69007 subjects aged 18 years or older were defined and divided into six groups on the basis of BMI and metabolic health status: metabolically healthy normal weight (MHNW), metabolically unhealthy normal weight (MUNW), metabolically healthy overweight (MHOW), metabolically unhealthy overweight (MUOW), metabolically healthy obesity (MHO), and metabolically unhealthy obesity (MUO). We estimated the odds ratios (ORs) and confidence intervals [CIs] for different thyroid disorders according to metabolic phenotypes using multivariate logistic regression models.

Results

In our study, we found that the prevalence of subclinical hypothyroidism was almost as high in the MUNW group as in the MUO group, the prevalence of overt hyperthyroidism was highest in the MUNW group and Graves' disease was highest in the MHO group. Our results also suggested that the prevalence of goiter and thyroid nodules increased with increased BMI values and that the MUO group had the highest incidence. Multivariate logistic regression analysis indicated that subjects with unhealthy metabolic phenotypes (MUNW, MUOW, and MUO) all had an increased risk of subclinical hypothyroidism, regardless of their BMI. MUNW subjects had an approximately 1.6-fold higher risk of overt hyperthyroidism and a 1.8-fold higher risk of Graves' disease than their metabolically healthy counterparts (MHNW). The present study also demonstrated that the MUO group had the highest risk of goiter and thyroid nodules among the metabolic phenotypes of obesity.

Conclusion

Based on our study, we found that metabolic abnormalities and obesity play different roles in various thyroid diseases. Metabolically unhealthy individuals, both with and without obesity, have a higher risk of thyroid disorders than metabolically healthy individuals without obesity.

Trends in Metabolic Phenotypes According to Body Mass Index Among US Adults, 1999-2018

OBJECTIVE

To examine the prevalence, distribution, and temporal trends of metabolic phenotypes that are jointly determined by obesity and metabolic health status among US adults, overall and in key population subgroups.

PARTICIPANTS AND METHODS

A nationally representative sample of civilian, noninstitutionalized US adults aged 20 years and older from the National Health and Nutrition Examination Survey between 1999-2000 and 2017-2018 were included. Metabolic phenotypes were characterized jointly by body mass index and metabolic health: metabolically healthy underweight, normal weight, overweight, and obese (MH-OB); and metabolically unhealthy underweight, normal weight, overweight, and obese (MU-OB). Metabolic health was defined using the 2009 joint scientific statement for metabolic syndrome from the International Diabetes Federation Task Force on Epidemiology and Prevention, National Heart, Lung, and Blood Institute, American Heart Association, World Heart Federation, International Atherosclerosis Society, and International Association for the Study of Obesity as having 2 or less components (primary analysis) or no components (secondary analysis) of the following: waist circumference of 102 cm or greater in men and 88 cm or greater in women, fasting plasma glucose level of 100 mg/dL or greater, blood pressure of 130/85 mm Hg or greater, triglyceride level of 150 mg/dL or greater, and high-density lipoprotein cholesterol level of less than 40 mg/dL in men and less than 50 mg/dL in women.

RESULTS

Of 19,941 adults, the mean age was 46.9 years; 10,005 (50.6%) were female. From 1999 to 2018, the prevalence in primary analysis declined from 33.2% (465465 of 1646) to 25.1% (454454 of 2058) (difference, -8.09%; 95% CI, -12.5% to -3.70%) for metabolically healthy normal weight, whereas it increased from 9.92% (178178 of 1646) to 14.1% (277277 of 2058) (difference, 4.17%; 95% CI, 1.13% to 7.21%) for MH-OB (both P<.001 for trend). The prevalence of metabolically healthy underweight and overweight remained stable at about 1.62% (298298 of 19,94119,941) (95% CI, 1.38% to 1.89%; P=.34 for trend) and 22.2% (4,275 of 19,941) (95% CI, 21.4% to 23.0%; P=.14 for trend), respectively. The prevalence declined from 3.77% (72 of 1646) to 2.10% (68 of 2058) (difference, -1.67%; 95% CI, -3.22% to -0.12%; P=.006 for trend) for metabolically unhealthy normal weight, whereas it increased from 19.0% (343 of 1646) to 26.4% (574 of 2058) (difference, 7.41%; 95% CI, 2.67% to 12.2%; P<.001 for trend) for MU-OB. The prevalence of metabolically unhealthy underweight and overweight remained stable at 0.06% (11 of 19,941) (95% CI, 0.03% to 0.15%; P=.84 for trend) and 11.2% (2528 of 19,941) (95% CI, 10.6% to 11.8%; P=.29 for trend), respectively. Persistent differences in the prevalence of metabolic phenotypes were identified across multiple sociodemographic subgroups. For example, the prevalence of MH-OB increased from 7.58% (53 of 754) to 12.0% (79 of 694) (P<.001 for trend) for non-Hispanic Whites and 12.2% (60 of 567) to 18.4% (76 of 493) for Hispanics (P=.01 for trend) and remained stable at 22.6% (756 of 3,825) for non-Hispanic Blacks (P=.62 for trend and P=.05 for interaction). Results in secondary analyses revealed similar patterns.

CONCLUSION

From 1999 to 2018, US adults experienced major increases in the prevalence of both MH-OB and MU-OB, largely due to decreases in MH-N. The prevalence of MU-OB increased across all subgroups, with higher values observed in older adults and those with lower education and income levels.

The AGEs/RAGE Transduction Signaling Prompts IL-8/CXCR1/2-Mediated Interaction between Cancer-Associated Fibroblasts (CAFs) and Breast Cancer Cells

Advanced glycation end products (AGEs) and the cognate receptor, named RAGE, are involved in metabolic disorders characterized by hyperglycemia, type 2 diabetes mellitus (T2DM) and obesity. Moreover, the AGEs/RAGE transduction pathway prompts a dysfunctional interaction between breast cancer cells and tumor stroma toward the acquisition of malignant features. However, the action of the AGEs/RAGE axis in the main players of the tumor microenvironment, named breast cancer-associated fibroblasts (CAFs), remains to be fully explored. In the present study, by chemokine array, we first assessed that interleukin-8 (IL-8) is the most up-regulated pro-inflammatory chemokine upon AGEs/RAGE activation in primary CAFs, obtained from breast tumors. Thereafter, we ascertained that the AGEs/RAGE signaling promotes a network cascade in CAFs, leading to the c-Fos-dependent regulation of IL-8. Next, using a conditioned medium from AGEs-exposed CAFs, we determined that IL-8/CXCR1/2 paracrine activation induces the acquisition of migratory and invasive features in MDA-MB-231 breast cancer cells. Altogether, our data provide new insights on the involvement of IL-8 in the AGEs/RAGE transduction pathway among the intricate connections linking breast cancer cells to the surrounding stroma. Hence, our findings may pave the way for further investigations to define the role of IL-8 as useful target for the better management of breast cancer patients exhibiting metabolic disorders.

Obesity and Breast Cancer Risk: The Oncogenic Implications of Metabolic Dysregulation

CONTEXT

Breast cancer is increasing in prevalence in parallel with rising rates of obesity worldwide. Obesity is recognized as a leading modifiable risk factor for the development of breast cancer; however, this association varies considerably by clinicopathologic features, and the underlying mechanisms are complex.

EVIDENCE ACQUISITION

Pubmed literature search using combinations of "obesity," "breast cancer risk," "diet," "exercise," "weight gain," "weight loss," "adipose tissue inflammation," "crown-like structure," "immune markers," "metformin," "gliflozins," "SGLT-2i," "GLP1-RA," and related terms.

EVIDENCE SYNTHESIS

Elevated body mass index and weight gain are associated with increased risk of postmenopausal, hormone receptor-positive breast cancer. Emerging evidence suggests that adverse measures of body composition in individuals of any weight can also confer increased breast cancer risk. Mechanistically, various factors including altered adipokine balance, dysfunctional adipose tissue, dysregulated insulin signaling, and chronic inflammation contribute to tumorigenesis. Weight loss and more specifically fat mass loss through lifestyle and pharmacologic interventions improve serum metabolic and inflammatory markers, sex hormone levels, and measures of breast density, suggesting a link to decreased breast cancer risk.

CONCLUSION

Incorporating markers of metabolic health and body composition measures with body mass index can capture breast cancer risk more comprehensively. Further studies of interventions targeting body fat levels are needed to curb the growing prevalence of obesity-related cancer.

Metabolically Defined Body Size Phenotypes and Risk of Endometrial Cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC)

BACKGROUND

Obesity is a risk factor for endometrial cancer but whether metabolic dysfunction is associated with endometrial cancer independent of body size is not known.

METHODS

The association of metabolically defined body size phenotypes with endometrial cancer risk was investigated in a nested case-control study (817 cases/ 817 controls) within the European Prospective Investigation into Cancer and Nutrition (EPIC). Concentrations of C-peptide were used to define metabolically healthy (MH; <1st tertile) and metabolically unhealthy (MU; ≥1st tertile) status among the control participants. These metabolic health definitions were combined with normal weight (NW); body mass index (BMI)<25 kg/m2 or waist circumference (WC)<80 cm or waist-to-hip ratio (WHR)<0.8) and overweight (OW; BMI≥25 kg/m2 or WC≥80 cm or WHR≥0.8) status, generating four phenotype groups for each anthropometric measure: (i) MH/NW, (ii) MH/OW, (iii) MU/NW, and (iv) MU/OW.

RESULTS

In a multivariable-adjusted conditional logistic regression model, compared with MH/NW individuals, endometrial cancer risk was higher among those classified as MU/NW [ORWC, 1.48; 95% confidence interval (CI), 1.05-2.10 and ORWHR, 1.68; 95% CI, 1.21-2.35] and MU/OW (ORBMI, 2.38; 95% CI, 1.73-3.27; ORWC, 2.69; 95% CI, 1.92-3.77 and ORWHR, 1.83; 95% CI, 1.32-2.54). MH/OW individuals were also at increased endometrial cancer risk compared with MH/NW individuals (ORWC, 1.94; 95% CI, 1.24-3.04).

CONCLUSIONS

Women with metabolic dysfunction appear to have higher risk of endometrial cancer regardless of their body size. However, OW status raises endometrial cancer risk even among women with lower insulin levels, suggesting that obesity-related pathways are relevant for the development of this cancer beyond insulin.

IMPACT

Classifying women by metabolic health may be of greater utility in identifying those at higher risk for endometrial cancer than anthropometry per se.

Metabolic dysfunction and obesity-related cancer: Beyond obesity and metabolic syndrome

OBJECTIVES

The metabolic dysfunction driven by obesity, including hyperglycemia and dyslipidemia, increases risk for developing at least 13 cancer types. The concept of "metabolic dysfunction" is often defined by meeting various combinations of criteria for metabolic syndrome. However, the lack of a unified definition of metabolic dysfunction makes it difficult to compare findings across studies. This review summarizes 129 studies that evaluated variable definitions of metabolic dysfunction in relation to obesity-related cancer risk and mortality after a cancer diagnosis. Strategies for metabolic dysfunction management are also discussed.

METHODS

A comprehensive search of relevant publications in MEDLINE (PubMed) and Google Scholar with review of references was conducted.

RESULTS

Metabolic dysfunction, defined as metabolic syndrome diagnosis or any number of metabolic syndrome criteria out of clinical range, inflammatory biomarkers, or markers of metabolic organ function, has been associated with risk for, and mortality from, colorectal, pancreatic, postmenopausal breast, and bladder cancers. Metabolic dysfunction associations with breast and colorectal cancer risk have been observed independently of BMI, with increased risk in individuals with metabolically unhealthy normal weight or overweight/obesity compared with metabolically healthy normal weight.

CONCLUSION

Metabolic dysfunction is a key risk factor for obesity-related cancer, regardless of obesity status. Nonetheless, a harmonized definition of metabolic dysfunction will further clarify the magnitude of the relationship across cancer types, enable better comparisons across studies, and further guide criteria for obesity-related cancer risk stratification.

Prolonged or Transition to Metabolically Unhealthy Status, Regardless of Obesity Status, Is Associated with Higher Risk of Cardiovascular Disease Incidence and Mortality in Koreans

The risk of chronic disease and mortality may differ by metabolic health and obesity status and its transition. We investigated the risk of cardiovascular disease (CVD) and cancer incidence and mortality according to metabolic health and obesity status and their transition using the nationally representative Korea National Health and Nutrition Examination Survey (KNHANES) and the Ansan-Ansung (ASAS) cohort of the Korean Genome and Epidemiology Study. Participants that agreed to mortality linkage (n = 28,468 in KNHANES and n = 7530 adults in ASAS) were analyzed (mean follow-up: 8.2 and 17.4 years, respectively). Adults with no metabolic risk factors and BMI <25 or ≥25 kg/m2 were categorized as metabolically healthy non-obese (MHN) or metabolically healthy obese (MHO), respectively. Metabolically unhealthy non-obese (MUN) and metabolically unhealthy obese (MUO) adults had ≥1 metabolic risk factor and a BMI < or ≥25 kg/m2, respectively. In KNHANES participants, MUN, and MUO had higher risks for cardiovascular mortality, but not cancer mortality, compared with MHN adults. MHO had 47% and 35% lower risks of cancer mortality and all-cause mortality, respectively, compared to MHN. Similar results were observed in the ASAS participants. Compared to those persistently MHN, the risk of CVD was greater when continuously MUN or MUO. Transitioning from a metabolically healthy state to MUO also increased the risk of CVD. Few associations were found for cancer incidence. Using a nationally representative cohort and an 18-year follow-up cohort, we observed that the risk of CVD incidence and mortality and all-cause mortality, but not cancer incidence or mortality, increases with a continuous or a transition to an unhealthy metabolic status in Koreans.

Metabolic Syndrome and Breast Cancer Molecular Subtypes: An Observational Patient Study

Background:

Breast cancer molecular subtypes share various prognostic profiles, and luminal A molecular subtypes have a better prognosis compared with other molecular subtypes. However, whether metabolic syndrome or individual risk factors of metabolic syndrome influence on the development of molecular subtype remains elusive. We aimed to assess the association between metabolic syndrome risk factors and breast cancer molecular subtypes among patients with metabolic syndrome in a clinical setting.

Methods:

In total, 101 breast cancer patients with mean age, 58.4 ± 8.5 years, and overt metabolic syndrome prospectively were recruited. Immunohistochemistry procedure was used to determine molecular subtypes. Assessment of clinical, biochemical, and anthropometric parameters was performed. Logistic regression analysis was used to assess the relationship between risk factors and breast cancer molecular subtypes categories. A similar approach was used to assess the relation between breast cancer molecular subtypes and menopause.

Results:

Comparison of metabolic syndrome individual risk factors according to breast cancer molecular subtypes no statistical difference was found for systolic (P = .33) and diastolic blood pressure (P = .17), fasting glucose (P = .77), triglycerides (P = .62), high-density lipoprotein (P = .33), body mass index (P = .87), and waist circumference (P = .81). A positive trend was found between high-density lipoprotein and HER2+. No association was found with other risk factors. Moreover, an association was found between HER2+ categories and menopause.

Conclusion:

In breast cancer patients with metabolic syndrome, we observed an increased trend between high-density lipoprotein and HER2+ molecular subtype, suggesting that underlying dyslipidemia may favor poor prognosis. HER2+ was associated with menopause which may influence further expression of HER2+ .

Insulin and cancer: a tangled web

For a century, since the pioneering work of Otto Warburg, the interwoven relationship between metabolism and cancer has been appreciated. More recently, with obesity rates rising in the U.S. and worldwide, epidemiologic evidence has supported a link between obesity and cancer. A substantial body of work seeks to mechanistically unpack the association between obesity, altered metabolism, and cancer. Without question, these relationships are multifactorial and cannot be distilled to a single obesity- and metabolism-altering hormone, substrate, or factor. However, it is important to understand the hormone-specific associations between metabolism and cancer. Here, we review the links between obesity, metabolic dysregulation, insulin, and cancer, with an emphasis on current investigational metabolic adjuncts to standard-of-care cancer treatment.

Association of a Healthy Lifestyle Index with Risk of Breast Cancer among Women with Normal Body Mass Index in the UK Biobank

BACKGROUND

A high healthy lifestyle index (HLI), a composite score based on good diet quality, low alcohol consumption, no smoking, moderate to high physical activity, and waist circumference <80 cm, has been consistently associated with a reduced risk of breast cancer. Recently, high levels of body fat were found to be associated with an elevated risk of breast cancer in postmenopausal women with a normal body mass index (BMI; 18.5-<25 kg/m2). Whether the HLI is associated with breast cancer risk in women with normal BMI is unknown.

METHODS

We studied 102,572 women aged 40 to 69 years with a normal BMI at enrollment into the UK Biobank cohort study. The HLI was created by assigning to each component higher scores for healthier behaviors and then summing the scores. The HLI was categorized by tertiles and age- and multivariable-adjusted HRs for the association of the HLI with breast cancer risk by menopausal status were estimated using Cox proportional hazards models.

RESULTS

In postmenopausal women, compared with a low HLI, higher scores were associated with a reduced risk of breast cancer [HRHLI-3rd tertile = 0.76; 95% confidence interval (CI), 0.64-0.91]. Findings were similar for premenopausal women, although they did not reach statistical significance, except when smoking status was excluded from the HLI score (HLIwithout smoking: HR3rd tertile = 0.71; 95% CI, 0.56-0.90).

CONCLUSIONS

In normal BMI postmenopausal women, a high HLI score was associated with a reduced risk of breast cancer.

IMPACT

Following a healthy lifestyle may reduce the risk of breast cancer among normal weight postmenopausal women.

The Association Between Metabolic Status and Risk of Cancer Among Patients With Obesity: Metabolically Healthy Obesity vs. Metabolically Unhealthy Obesity

Background

Controversial evidence about the association between cancer risk and metabolic status among individuals with obesity has been reported, but pooled data remain absent. This study aims to present pooled data comparing cancer risk between patients with metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO).

Methods

The current study systematically searched pieces of literature on January 4, 2021, of prospective cohorts that compare the incidence of cancer between MHO and MUO. The quality of included studies was assessed using Newcastle-Ottawa scale, and publication bias was evaluated using funnel plots.

Results

Eleven high-quality studies were eventually selected. Quantitative analysis indicates that a lower cancer incidence exists for MHO phenotype than that for MUO (odds ratio [OR], 0.71; 95% confidential interval [CI], 0.61-0.84). Consistent outcomes are presented by subgroup analyses, which are grouped by cohort region (western population: [OR, 0.84; 95% CI, 0.75-0.93]; Asian population: [OR, 0.64; 95% CI, 0.54-0.77]); definition of metabolic unhealthiness (≥3 metabolic abnormalities: [OR, 0.62; 95% CI, 0.54-0.71]; ≥1 metabolic abnormality: [OR, 0.76; 95% CI, 0.62-0.94]); and definition of obesity (body mass index (BMI), ≥30 kg/m2: [OR, 0.84; 95% CI, 0.73-0.98]; BMI, ≥25 kg/m2: [OR, 0.53; 95% CI, 0.52-0.55]).

Conclusion

In conclusion, this study suggests a reduced cancer risk for MHO compared to MUO regardless of population heterogeneity, or the definitions of obesity and metabolic status.

The ambiguous role of obesity in oncology by promoting cancer but boosting antitumor immunotherapy

Obesity is nowadays considered a pandemic which prevalence's has been steadily increasingly in western countries. It is a dynamic, complex, and multifactorial disease which propitiates the development of several metabolic and cardiovascular diseases, as well as cancer. Excessive adipose tissue has been causally related to cancer progression and is a preventable risk factor for overall and cancer-specific survival, associated with poor prognosis in cancer patients. The onset of obesity features a state of chronic low-grade inflammation and secretion of a diversity of adipocyte-derived molecules (adipokines, cytokines, hormones), responsible for altering the metabolic, inflammatory, and immune landscape. The crosstalk between adipocytes and tumor cells fuels the tumor microenvironment with pro-inflammatory factors, promoting tissue injury, mutagenesis, invasion, and metastasis. Although classically established as a risk factor for cancer and treatment toxicity, recent evidence suggests mild obesity is related to better outcomes, with obese cancer patients showing better responses to treatment when compared to lean cancer patients. This phenomenon is termed obesity paradox and has been reported in different types and stages of cancer. The mechanisms underlying this paradoxical relationship between obesity and cancer are still not fully described but point to systemic alterations in metabolic fitness and modulation of the tumor microenvironment by obesity-associated molecules. Obesity impacts the response to cancer treatments, such as chemotherapy and immunotherapy, and has been reported as having a positive association with immune checkpoint therapy. In this review, we discuss obesity's association to inflammation and cancer, also highlighting potential physiological and biological mechanisms underlying this association, hoping to clarify the existence and impact of obesity paradox in cancer development and treatment.

A review of menopause nomenclature

Menopause nomenclature varies in the scholarly literature making synthesis and interpretation of research findings difficult. Therefore, the present study aimed to review and discuss critical developments in menopause nomenclature; determine the level of heterogeneity amongst menopause definitions and compare them with the Stages of Reproductive Aging Workshop criteria. Definitions/criteria used to characterise premenopausal and postmenopausal status were extracted from 210 studies and 128 of these studies were included in the final analyses. The main findings were that 39.84% of included studies were consistent with STRAW classification of premenopause, whereas 70.31% were consistent with STRAW classification of postmenopause. Surprisingly, major inconsistencies relating to premenopause definition were due to a total lack of reporting of any definitions/criteria for premenopause (39.84% of studies). In contrast, only 20.31% did not report definitions/criteria for postmenopause. The present findings indicate that there is a significant amount of heterogeneity associated with the definition of premenopause, compared with postmenopause. We propose three key suggestions/recommendations, which can be distilled from these findings. Firstly, premenopause should be transparently operationalised and reported. Secondly, as a minimum requirement, regular menstruation should be defined as the number of menstrual cycles in a period of at least 3 months. Finally, the utility of introducing normative age-ranges as supplementary criterion for defining stages of reproductive ageing should be considered. The use of consistent terminology in research will enhance our capacity to compare results from different studies and more effectively investigate issues related to women's health and ageing.

Preventing ovariectomy-induced weight gain decreases tumor burden in rodent models of obesity and postmenopausal breast cancer

BACKGROUND

Obesity and adult weight gain are linked to increased breast cancer risk and poorer clinical outcomes in postmenopausal women, particularly for hormone-dependent tumors. Menopause is a time when significant weight gain occurs in many women, and clinical and preclinical studies have identified menopause (or ovariectomy) as a period of vulnerability for breast cancer development and promotion.

METHODS

We hypothesized that preventing weight gain after ovariectomy (OVX) may be sufficient to prevent the formation of new tumors and decrease growth of existing mammary tumors. We tested this hypothesis in a rat model of obesity and carcinogen-induced postmenopausal mammary cancer and validated our findings in a murine xenograft model with implanted human tumors.

RESULTS

In both models, preventing weight gain after OVX significantly decreased obesity-associated tumor development and growth. Importantly, we did not induce weight loss in these animals, but simply prevented weight gain. In both lean and obese rats, preventing weight gain reduced visceral fat accumulation and associated insulin resistance. Similarly, the intervention decreased circulating tumor-promoting growth factors and inflammatory cytokines (i.e., BDNF, TNFα, FGF-2), with greater effects in obese compared to lean rats. In obese rats, preventing weight gain decreased adipocyte size, adipose tissue macrophage infiltration, reduced expression of the tumor-promoting growth factor FGF-1 in mammary adipose, and reduced phosphorylated FGFR indicating reduced FGF signaling in tumors.

CONCLUSIONS

Together, these findings suggest that the underlying mechanisms associated with the anti-tumor effects of weight maintenance are multi-factorial, and that weight maintenance during the peri-/postmenopausal period may be a viable strategy for reducing obesity-associated breast cancer risk and progression in women.

Association of Metabolic Health and Central Obesity With the Risk of Thyroid Cancer: Data from the Korean Genome and Epidemiology Study

BACKGROUND

It is unknown whether the risk of thyroid cancer differs among metabolically healthy/unhealthy, normal-weight, or obese women. We aimed to assess the association of metabolic health and obesity with thyroid cancer risk.

METHODS

The Korean Genome and Epidemiology Study is a population-based prospective cohort study. Data were obtained from 173,343 participants (age {greater than or equal to}40 years) enrolled from 2004 to 2013. Obese participants were those with body mass index (BMI) {greater than or equal to}25 kg/m2. Participants with abnormalities in three of these indices were considered metabolically unhealthy: triglycerides, blood pressure, high-density lipoprotein cholesterol (HDL-cholesterol), waist circumference (WC), and fasting glucose levels. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for thyroid cancer risk associated with metabolic health and obesity.

RESULTS

Compared to non-obese women without metabolic abnormalities, metabolically unhealthy women, either normal-weight or obese, had an increased risk of thyroid cancer (HR [95% CI]=1.57[1.02-2.40] and 1.71[1.21-2.41], respectively). Significant association was not observed in men. Thyroid cancer risk was higher among non-obese women with high WC ({greater than or equal to}85 cm; HR [95% CI]=1.62[1.03-2.56]) than in non-obese women with low WC, and in obese women with low HDL-cholesterol (<50 mg/dL; HR[95% CI]=1.75[1.26-2.42]) compared to non-obese women with high HDL-cholesterol.

CONCLUSIONS

Metabolically unhealthy women or women with central adiposity may be at an increased thyroid cancer risk despite normal BMI.

IMPACT

This study suggests that women with central obesity and metabolically abnormality despite normal BMI may constitute a target group for thyroid cancer prevention and control programs.

Novel Mechanisms of Tumor Promotion by the Insulin Receptor Isoform A in Triple-Negative Breast Cancer Cells

The insulin receptor isoform A (IR-A) plays an increasingly recognized role in fetal growth and tumor biology in response to circulating insulin and/or locally produced IGF2. This role seems not to be shared by the IR isoform B (IR-B). We aimed to dissect the specific impact of IR isoforms in modulating insulin signaling in triple negative breast cancer (TNBC) cells. We generated murine 4T1 TNBC cells deleted from the endogenous insulin receptor (INSR) gene and expressing comparable levels of either human IR-A or IR-B. We then measured IR isoform-specific in vitro and in vivo biological effects and transcriptome in response to insulin. Overall, the IR-A was more potent than the IR-B in mediating cell migration, invasion, and in vivo tumor growth. Transcriptome analysis showed that approximately 89% of insulin-stimulated transcripts depended solely on the expression of the specific isoform. Notably, in cells overexpressing IR-A, insulin strongly induced genes involved in tumor progression and immune evasion including chemokines and genes related to innate immunity. Conversely, in IR-B overexpressing cells, insulin predominantly induced the expression of genes primarily involved in the regulation of metabolic pathways and, to a lesser extent, tumor growth and angiogenesis.

High waist-to-height ratio and associated factors in adolescents from a city in Southern Brazil: a cross-sectional study

Objective:

To verify the prevalence of abdominal obesity with the waist-to-height ratio (WHtR) and associated factors in adolescents from a city in Southern Brazil.

Methods:

A total of 960 adolescents (494 boys) aged 15–18 years old participated in this study. The dependent variable was WHtR; independent variables were self-reported age, economic level, sexual maturation, physical activity level, screen time, and body fat. Data were analyzed using descriptive statistics and logistic regression.

Results:

It was observed that 36.7% of the adolescents presented high WHtR (50.2% in girls and 23.9% in boys). Regardless of sex, adolescents with high body fat were more likely of having high WHtR (boys: Odds Ratio [OR] 29.79; 95% confidence interval [95%CI] 16.87–52.62; girls: OR 19.43; 95%CI 10.51–35.94). In girls, high WHtR was associated with age (OR 1.83; 95%CI 1.17–2.87), and in boys, with economic level (OR 2.34; 95%CI 1.01–5.45).

Conclusions:

One in each three adolescents has abdominal obesity. Among adolescents with high body fat, girls aged 15–16 and boys with high-income are the groups most exposed to abdominal obesity.

Time-Restricted Eating: A Novel and Simple Dietary Intervention for Primary and Secondary Prevention of Breast Cancer and Cardiovascular Disease

There is substantial overlap in risk factors for the pathogenesis and progression of breast cancer (BC) and cardiovascular disease (CVD), including obesity, metabolic disturbances, and chronic inflammation. These unifying features remain prevalent after a BC diagnosis and are exacerbated by BC treatment, resulting in elevated CVD risk among survivors. Thus, therapies that target these risk factors or mechanisms are likely to be effective for the prevention or progression of both conditions. In this narrative review, we propose time-restricted eating (TRE) as a simple lifestyle therapy to address many upstream causative factors associated with both BC and CVD. TRE is simple dietary strategy that typically involves the consumption of ad libitum energy intake within 8 h, followed by a 16-h fast. We describe the feasibility and safety of TRE and the available evidence for the impact of TRE on metabolic, cardiovascular, and cancer-specific health benefits. We also highlight potential solutions for overcoming barriers to adoption and adherence and areas requiring future research. In composite, we make the case for the use of TRE as a novel, safe, and feasible intervention for primary and secondary BC prevention, as well as tertiary prevention as it relates to CVD in BC survivors.

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.

Associations of General and Abdominal Obesity with the Risk of Glioma Development

Simple Summary

While obesity is a well-known risk factor for the development of various types of cancer, conflicting results have been reported concerning the relationship between obesity and the risk of glioma. To date, no studies have evaluated the association between obesity and risk of glioma development in Eastern Asian populations, who usually have greater fat mass and less muscle and are more likely to develop several metabolic diseases than Western populations of the same body mass index (BMI) category. In this nationwide population-based study, we suggest, for the first time, positive associations of general and central obesity with the risk of glioma development. In addition, we demonstrate a stronger association between abdominal obesity and the risk of glioma development than BMI and the risk of glioma development.

Abstract

The association between obesity and the risk of glioma remains unclear. We sought to evaluate the potential association between general and abdominal obesity and the risk of glioma based on a nationwide population-based cohort study of Koreans. Using data from the Korean National Health Insurance System cohort, 6,833,744 people older than 20 years who underwent regular national health examination in both 2009 and 2011 were followed until the end of 2017. We documented 4771 glioma cases based on an ICD-10 code of C71 during the median follow-up period of 7.30 years. Individuals with a body mass index (BMI) ≥ 25.0 kg/m² were at significantly higher risk of developing glioma than those with a BMI < 25.0 kg/m² (HR 1.08 CI 1.02–1.15). Individuals with a waist circumference (WC) ≥ 90 cm (males)/85 cm (females) also had a significantly higher risk of glioma than those with a WC < 90 cm (males)/85 cm (females) (HR 1.16 CI 1.09–1.24). In the group with a BMI ≥ 25.0 kg/m², individuals with abdominal obesity were at significantly higher risk of developing glioma (HR 1.18 CI 1.09–1.27) than those without abdominal obesity. The role of abdominal obesity in this association was stronger in women than in men. To the best of our knowledge, this is the first demonstration that obese people may be at higher risk of glioma, especially centrally obese people from an Asian population with a BMI ≥ 25.0 kg/m². Loss of visceral fat in people with abdominal obesity may reduce their risk of developing glioma.

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.

Cancer Risk in Normal Weight Individuals with Metabolic Obesity: A Narrative Review

Obesity represents one of the most significant public health challenges worldwide. Current clinical practice relies on body mass index (BMI) to define the obesity status of an individual, even though the index has long been recognized for its limitations as a measure of body fat. In normal BMI individuals, increased central adiposity has been associated with worse health outcomes, including increased risks of cardiovascular disease and metabolic disorders. The condition leading to these outcomes has been described as metabolic obesity in the normal weight (MONW). More recent evidence suggests that MONW is associated with increased risk of several obesity-related malignancies, including postmenopausal breast, endometrial, colorectal, and liver cancers. In MONW patients, the false reassurance of a normal range BMI can lead to lost opportunities for implementing preventive interventions that may benefit a substantial number of people. A growing body of literature has documented the increased risk profile of MONW individuals and demonstrated practical uses for body composition and biochemical analyses to identify this at-risk population. In this review, we survey the current literature on MONW and cancer, summarize pathophysiology and oncogenic mechanisms, highlight potential strategies for diagnosis and treatment, and suggest directions for future research.

The association of body fat composition with risk of breast, endometrial, ovarian and colorectal cancers among normal weight participants in the UK Biobank

BACKGROUND

The association between body fat composition and risk of cancer in normal weight individuals (body mass index (BMI) 18.5-24.9 kg/m2) is unclear.

METHODS

We examined the association of measures of adiposity with risk of incident cancers of the breast (postmenopausal), endometrium, ovary and colon/rectum among 149,928 normal weight individuals (40-70 years) who were enrolled in the UK Biobank cohort between 2006 and 2010.

RESULTS

All of the body fat measures were positively associated with invasive postmenopausal breast cancer risk (hazard ratios (HR) for the uppermost quintile (Q5) versus the lowest quintile (Q1) ranged from 1.32 (95% CI: 1.09-1.60) for waist circumference (WC) to 1.56 (1.28-1.90) for BMI). Trunk fat mass index (HRQ5 vs Q1: 1.72, 95% CI: 1.02-2.89) and WC (HRQ5 vs Q1: 1.65, 95% CI: 1.01-2.70)) were positively associated with risk of endometrial cancer. Among males, trunk fat:trunk fat free mass ratio, trunk fat:leg fat mass ratio and (HRQ5 vs Q1: 1.63, 95% CI: 1.02-2.60; 1.92, 1.20-3.07 and 1.68, 1.05-2.66, respectively) were positively associated with colon cancer risk. None of the body fat measures was associated with risk of ovarian cancer or colorectal cancer in women.

CONCLUSION

The findings of this study suggest that the current normal weight category based on BMI includes individuals who are at increased risk of some obesity-related cancers.

The Tumor Promotional Role of Adipocytes in the Breast Cancer Microenvironment and Macroenvironment

The role of the adipocyte in the tumor microenvironment has received significant attention as a critical mediator of the obesity-cancer relationship. Current estimates indicate that 650 million adults have obesity, and thirteen cancers, including breast cancer, are estimated to be associated with obesity. Even in people with a normal body mass index, adipocytes are key players in breast cancer progression because of the proximity of tumors to mammary adipose tissue. Outside the breast microenvironment, adipocytes influence metabolic and immune function and produce numerous signaling molecules, all of which affect breast cancer development and progression. The current epidemiologic data linking obesity, and importantly adipose tissue, to breast cancer risk and prognosis, focusing on metabolic health, weight gain, and adipose distribution as underlying drivers of obesity-associated breast cancer is presented here. Bioactive factors produced by adipocytes, both normal and cancer associated, such as cytokines, growth factors, and metabolites, and the potential mechanisms through which adipocytes influence different breast cancer subtypes are highlighted.

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.

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

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

Associations of Biomarkers of Inflammation and Breast Cancer in the Breast Adipose Tissue of Women with Combined Measures of Adiposity

BACKGROUND

Mechanisms underlying the obesity-breast cancer link involve inflammation but need to be elucidated. Determining obesity by combining body mass index (BMI) with the waist circumference (WC) may clarify the role of inflammatory and hormonally related markers in breast cancer. We examined the effect of combining adiposity indices (BMI/WC) with the gene expression of several biomarkers involved in breast cancer.

METHODS

Expression of cytochrome P450 family 19 subfamily A member 1 (CYP19A1), estrogen receptor-alpha (ER-α), allograft inflammatory factor 1 (AIF1), cyclooxygenase-2 (COX2), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and leptin (LEP) in 141 adipose breast tissues was quantified using qPCR method. BMI and WC were measured by a trained nurse and categorized using the median split, BMI^LOWC^LO, BMI^LOWC^HI, BMI^HIWC^LO, and BMI^HIWC^HI.

RESULTS

Gene expression of IL-6 (3-fold), TNF-α (2-fold), and LEP (2-fold) was higher in the breast adipose tissue of women with high WC regardless of BMI, that is, BMI^LOWC^HI and BMI^HIWC^HI women (all P < 0.01). Compared to BMI^LOWC^LO women, gene expression of CYP19A1, COX2, and AIF1 was increased by two-fold in breast adipose tissue of BMI^HIWC^HI women (P < 0.10). ER-α was not different across adiposity categories.

CONCLUSIONS

The expression of some biomarkers, particularly those related to inflammation, is elevated in breast adipose tissue of women with a high WC independent of BMI. Obesity monitoring should also include women with normal or low BMI, but with central adiposity.

Visceral obesity and incident cancer and cardiovascular disease: An integrative review of the epidemiological evidence

Evidence shows a strong relationship between obesity, cancer and cardiovascular disease (CVD) risk. However, there is not enough evidence of the role of visceral obesity on both CVD and cancer. Visceral obesity may be more pro-oncogenic than total body fat. Therefore, it is important to know whether abdominal obesity can lead to both CVD and cancer. The present integrative review aimed at evaluating epidemiological evidence on the potential connection of visceral obesity in the occurrence of cancer and CVD. The following databases were searched: SCOPUS, PubMed, Science Direct, Lilacs, SciELO, Google Scholar, Web of Science, Scopus and ProQuest. The presence of visceral obesity can increase the risk of some specific cancer types, but there is controversial evidence about CVD risk based on sex-specific and ageing analyses. There is enough evidence that visceral obesity increases the risk of colorectal, pancreatic and gastro-oesophageal cancer. However, for some types of cancer such as breast, endometrial and renal, visceral obesity is a risk only in post-menopausal women. Regarding prostate cancer, the evidence is controversial. Despite the risk of visceral obesity being consistently associated with CVD in adults, this association disappears in sex-specific and older adults analyses. Moreover, in older adults, the results are controversial due to the use of different measures such as waist circumference and visceral adipose tissue. However, the evidence showing visceral obesity as a risk factor to CVD remains controversial. Sex differences, ageing and body mass index (BMI) category can potentially modify this association. Therefore, further epidemiological studies with analyses stratified by sex and samples including older adults aged 65 and older are needed.

Apolipoprotein A1 and Low-Density Lipoprotein as Risk Factors for Intraocular Metastases in Postmenopausal Breast Cancer

BACKGROUND

The outcomes of patients with postmenopausal breast cancer(PBC) can be improved through the early detection of intraocular metastases(IOMs). In this study, we investigated patients with PBC, and compared those with IOMs with those with non-intraocular metastases(NIOMs) in terms of blood lipid levels, and then differentiated the risk factors associated with IOMs.

METHODS

Student's t-test and a chi-square test were used to discriminate between the IOMs and NIOMs groups. After establishing a Poisson regression model to analyze risk factors, we plotted receiver operating characteristic curves(ROC) to assess the quality of risk factors predicting IOMs.

RESULTS

The incidence of IOMs in PBC was 1.16%. There was no significant difference in terms of histopathology between the 2 groups. The levels of total cholesterol (TC), apolipoprotein A1(APOA1) and low-density lipoprotein(LDL) in IOMs were significantly lower than in NIOMs groups. Poisson regression suggested that low levels of APOA1 and LDL were risk factors for IOMs (P = 0.002 and P < 0.001, respectively). ROC curve analysis demonstrated that the cut-off values of APOA1 and LDL were 1.025 g/L and 2.415 mmol/L. The highest prediction accuracy for IOMs involved the combination of APOA1 and LDL (AUC = 0.881, P < 0.001).

CONCLUSION

Our research demonstrates that low levels of APOA1 and LDL efficiently predict IOMs in PBC as risk factors, and the combination of APOA1 and LDL was more predictive than single factors.

Microenvironmental Determinants of Breast Cancer Metastasis: Focus on the Crucial Interplay Between Estrogen and Insulin/Insulin-Like Growth Factor Signaling

The development and progression of the great majority of breast cancers (BCs) are mainly dependent on the biological action elicited by estrogens through the classical estrogen receptor (ER), as well as the alternate receptor named G-protein–coupled estrogen receptor (GPER). In addition to estrogens, other hormones and growth factors, including the insulin and insulin-like growth factor system (IIGFs), play a role in BC. IIGFs cooperates with estrogen signaling to generate a multilevel cross-communication that ultimately facilitates the transition toward aggressive and life-threatening BC phenotypes. In this regard, the majority of BC deaths are correlated with the formation of metastatic lesions at distant sites. A thorough scrutiny of the biological and biochemical events orchestrating metastasis formation and dissemination has shown that virtually all cell types within the tumor microenvironment work closely with BC cells to seed cancerous units at distant sites. By establishing an intricate scheme of paracrine interactions that lead to the expression of genes involved in metastasis initiation, progression, and virulence, the cross-talk between BC cells and the surrounding microenvironmental components does dictate tumor fate and patients’ prognosis. Following (i) a description of the main microenvironmental events prompting BC metastases and (ii) a concise overview of estrogen and the IIGFs signaling and their major regulatory functions in BC, here we provide a comprehensive analysis of the most recent findings on the role of these transduction pathways toward metastatic dissemination. In particular, we focused our attention on the main microenvironmental targets of the estrogen-IIGFs interplay, and we recapitulated relevant molecular nodes that orientate shared biological responses fostering the metastatic program. On the basis of available studies, we propose that a functional cross-talk between estrogens and IIGFs, by affecting the BC microenvironment, may contribute to the metastatic process and may be regarded as a novel target for combination therapies aimed at preventing the metastatic evolution.

Effect of Metabolic Health and Obesity Phenotype on the Risk of Pancreatic Cancer: A Nationwide Population-Based Cohort Study

BACKGROUND

Recently, a few studies have reported different results regarding the relationship between metabolic health and obesity phenotype and several cancers. We examined the effects of metabolic health and obesity phenotype on pancreatic cancer using a nationwide population-based cohort database.

METHODS

Using the Korean National Health Insurance Service-Health Screening Cohort, we enrolled 347,434 Korean adults who underwent a health examination between 2009 and 2010 and were followed until 2015. This population was divided into four groups based on metabolically healthy status and body mass index (BMI): metabolically healthy normal weight (MHNW), metabolically unhealthy normal weight (MUNW), metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO).

RESULTS

Over a median follow-up of 6.1 (5.5-6.5) years, 886 individuals were diagnosed with pancreatic cancer. The adjusted HRs for incident pancreatic cancer were 1.52 [95% confidence interval (CI) 1.27-1.81] and 1.34 (95% CI, 1.12-1.61) for the MUNW and MUO phenotypes (compared with the MHNW phenotype) after adjusting for various confounding factors. However, compared with the MHNW phenotype, the MHO phenotype did not show an elevated risk of pancreatic cancer. Moreover, the HR for pancreatic cancer gradually increased with an increase in number of metabolically unhealthy components, even after adjusting for BMI (P _trend < 0.001).

CONCLUSIONS

Regardless of BMI, metabolically unhealthy phenotype demonstrated significantly increased risk of pancreatic cancer, whereas obese individuals with metabolically healthy phenotype did not.

IMPACT

These findings suggest that metabolically unhealthy phenotype might represent a potential risk factor for pancreatic cancer occurrence independent of obesity.

Preclinical Models to Study Obesity and Breast Cancer in Females: Considerations, Caveats, and Tools

Obesity increases the risk for breast cancer and is associated with poor outcomes for cancer patients. A variety of rodent models have been used to investigate these relationships; however, key differences in experimental approaches, as well as unique aspects of rodent physiology lead to variability in how these valuable models are implemented. We combine expertise in the development and implementation of preclinical models of obesity and breast cancer to disseminate effective practices for studies that integrate these fields. In this review, we share, based on our experience, key considerations for model selection, highlighting important technical nuances and tips for use of preclinical models in studies that integrate obesity with breast cancer risk and progression. We describe relevant mouse and rat paradigms, specifically highlighting differences in breast tumor subtypes, estrogen production, and strategies to manipulate hormone levels. We also outline options for diet composition and housing environments to promote obesity in female rodents. While we have applied our experience to understanding obesity-associated breast cancer, the experimental variables we incorporate have relevance to multiple fields that investigate women's health.

Metabolic Syndrome and Risk of Lung Cancer: An Analysis of Korean National Health Insurance Corporation Database

INTRODUCTION

Metabolic syndrome is known to increase the risk of several cancers. However, the association between lung cancer and metabolic syndrome remains unclear. Thus, we investigated the impact of metabolic syndrome on the incidence of lung cancer.

METHODS

This study enrolled participants in a health screening program provided by the Korean National Health Insurance Service between January 2009 and December 2012. The incidence of lung cancer was observed until December 2016. We analyzed the risk of lung cancer according to the presence of metabolic syndrome, metabolic syndrome components, and number of metabolic syndrome components.

RESULTS

During the study, 45 635 new cases of lung cancer were recorded among 9 586 753 participants. The presence of metabolic syndrome and all its components was positively associated with the risk of lung cancer in men after multivariate adjustment (hazard ratio [HR] of metabolic syndrome 1.15; 95% confidence interval [CI], 1.12-1.18). The risk of lung cancer increased with the number of components present. The effect of metabolic syndrome on the increasing risk of lung cancer is may be higher in underweight male ever-smokers than in other participants.

CONCLUSION

Metabolic syndrome was associated with an increased risk of lung cancer in men. Moreover, the higher the number of metabolic syndrome components, the higher the risk of lung cancer.

Associations of general obesity and central obesity with the risk of hepatocellular carcinoma in a Korean population: A national population-based cohort study

Numerous previous studies have shown an association between general obesity and hepatocellular carcinoma (HCC). However, relatively few reports on the association of central obesity and HCC are available in Asian populations. Therefore, we investigated the association between WC representing central obesity and the risk of HCC in addition to BMI representing general obesity and the risk of HCC in Korea. A total of 10 505 818 participants who received the National Health Insurance Service (NHIS) health checkups in 2009 were screened for study eligibility, and 26 979 cases of HCC occurred during the 7.3 years of mean follow-up. General obesity increased the risk of HCC with hazard ratios (HRs) of 1.14 (95% CI, 1.11-1.18) for BMI 25.0-<30.0 kg/m² and 1.52 (95% CI, 1.43-1.61) for BMI ≥30 kg/m² compared to those whose BMI is within the normal range. Central obesity was also associated with a higher risk of HCC. For the participants with a WC ≥105 cm in men and WC ≥100 cm in women, the risk of HCC was higher than that of the reference group (HR = 1.69, 95% CI, 1.54-1.85). The HRs were 1.13 (95% CI, 1.07-1.19) for nonobese participants with central obesity, and 1.34 (95% CI, 1.30-1.38) for obese participants with central obesity compared to those without both conditions. Our findings suggest that the risk of HCC increases even more when general obesity is combined with central obesity. Moreover, central obesity is associated with the risk of HCC, regardless of general obesity.

The association between metabolically healthy obesity and risk of cancer: A systematic review and meta-analysis of prospective cohort studies

The risk of cancer among adults with metabolically healthy obesity (MHO) has not yet been established. We systematically searched from inception to 15 March 2020. We included prospective cohort studies that compared participants with MHO and participants with metabolically healthy non-obesity (MHNO) for incidence of any type of cancer. Benign tumors, cancer mortality or cancer prognosis were not in the scope of our analysis. The Newcastle-Ottawa Scale was used for quality assessment. Ultimately, eight studies with a total of 12 542 390 participants were included. The pooled meta-analysis using random effect model showed participants with MHO demonstrated a significantly increased risk of developing cancer (odds ratio [OR], 1.14; 95% confidence interval [CI], 1.05 to 1.23; and I² = 39%) than those with MHNO. The subgroup analysis revealed a higher pooled estimate (OR, 1.17; 95% CI, 1.01-1.35; and I² = 56%) in comparison with metabolically healthy normal weight. No evidence of effect modification by age, sex, ethnicity, smoking, sample size or length of follow-up was found. In conclusion, the present study reports a positive association between MHO and cancer incidence. All individuals with obesity, even in the absence of metabolic dysfunction, should be encouraged to lose weight.