Upper abdominal obesity, insulin resistance and breast cancer risk

Weight-adjusted-waist index: an innovative indicator of breast cancer hazard

BACKGROUND

Central obesity and breast cancer (BC) have been identified as relevant by empirical research. The weight-adjusted-waist index (WWI) is a novel methodology for quantifying central obesity. Inspection of the association between WWI and BC in American adult women was the primary goal of the current investigation.

METHODS

Cross-sectional assessments were conducted on information gathered from 10,193 National Health and Nutrition Examination Survey (NHANES) participants from 2011 to 2018. The waist circumference was divided by the square root of the body's mass to compute WWI. Data were assessed via descriptive statistics to present data distributions according to BC grouping and WWI grouping, receiver operating characteristic curves (ROCs) to evaluate the obesity indicators' applied value, logistic regression to reflect associations between WWI and BC prevalence, and restricted cubic splines (RCSs) and subgroup analysis forest plots to visualise and complement the relationships.

RESULTS

This study enrolled 10,193 participants whose WWI ranged from 8.38 to 14.41, 259 of whom were diagnosed with BC, and the results revealed significant differences in baseline characteristics between the groups. With an area under the curve (AUC) value (95% confidence interval) (CI)of 0.611 (0.577-0.644), WWI was a promising indicator of BC with good application value rather than waist circumference (WC), body mass index (BMI), or waist-height ratio (WHtR). WWI and BC laid out a substantial relationship, yielding an odds ratio (OR) of 1.54 and a 95% CI of (1.34, 1.79), which remained at 1.19 (1.00, 1.42) after considerable adjustments were made, according to the logistic regression analysis. Compared with the lowest quartile of WWI, the highest quartile had a 62% greater in the probability of suffering from BC. With the RCS's inverted U-shape highlighting the importance of considering the nonlinear nature of the relationship and subgroup analyses reflecting variations among populations, all the results demonstrated that WWI was a well-suggestive indicator of BC hazard.

CONCLUSION

The current investigation revealed a meaningful association between the prevalence of BC and WWI, which was superior to other obesity indicators, albeit one that was more complex than the positive relationship initially derived. There existed a turning point for BC prevalence at WWI of approximately 12 cm/√kg. Nevertheless, maintaining WWI in the lower range is critical for preventing and administering BC and minimizing disease risk.

Postmenopausal overweight and breast cancer risk; results from the KARMA cohort

Purpose

To study the risk of incident breast cancer and subtype-specific breast cancer in relation to excess body weight in a contemporary Swedish prospective cohort study, The Karolinska Mammography Project for Risk Prediction of Breast Cancer, KARMA.

Methods

A total of 35,412 postmenopausal women attending mammography and included in the KARMA study provided baseline data on body mass index (BMI) and potential confounders. During eight years of follow-up, 822 incident invasive breast cancer cases were identified.

Results

Women with overweight (BMI ≥ 25–< 30 kg/m²) constituting 34% of the study cohort had an increased risk of incident breast cancer with an adjusted Hazard Ratio (HR_adj) 1.19 (95% CI 1.01–1.4). A similar, however, non-significant, association was found for women with obesity (BMI ≥ 30 kg/m²) conferring 13% of the cohort, with a HR_adj of 1.19 (95% CI 0.94–1.5). Overweight was associated with risk of node-negative disease (HR_adj 1.29, 95% CI 1.06–1.58), whereas obesity was associated with node-positive disease (HR_adj 1.64, 95% CI 1.09–2.48). Both overweight and obesity were associated with risk of estrogen receptor positive (ER+) disease (HR_adj 1.20, 95% CI 1.00–1.44 and HR_adj 1.33, 95% CI 1.03–1.71, respectively), and low-grade tumors (HR_adj 1.25, 95% CI 1.02–1.54, and HR_adj 1.40, 95% CI 1.05–1.86, respectively). Finally, obesity was associated with ER+HER2 negative disease (HR_adj 1.37, 95% CI 1.05–1.78) and similarly luminal A tumors (HR_adj 1.43, 95% CI 1.02–2.01).

Conclusion

Overweight and obesity are associated with an increased risk of developing breast cancer, specifically ER+, low-grade, and for obesity, node-positive, high-risk breast cancer indicating a further need for risk communication and preventive programs.

Short-term effects of a Paleolithic lifestyle intervention in breast cancer patients undergoing radiotherapy: a pilot and feasibility study

Evolutionary principles are rarely considered in clinical oncology. We here aimed to test the feasibility and effects of a dietary and physical activity intervention based on evolutionary considerations in an oncological setting. A total of 13 breast cancer patients referred to our clinic for curative radiotherapy were recruited for this pilot study. The women were supposed to undertake a "Paleolithic lifestyle" (PL) intervention consisting of a Paleolithic diet and daily outdoor activity of at least 30 min duration while undergoing radiotherapy. Body composition was measured weekly by bioimpedance analysis. Blood parameters were assessed before, during, and at the end of radiotherapy. A control group on an unspecified standard diet (SD) was assigned by propensity score matching. A total of eleven patients completed the study. The majority of patients (64%) reported feeling good or very good during the intervention. The intervention group experienced an average decrease of 0.4 kg body weight (p < 0.001) and 0.34 kg (p < 0.001) fat mass per week, but fat-free and skeletal muscle mass were not significantly affected. Vitamin D levels increased slightly from 23.8 (11-37.3) ng/ml to 25.1 (22.6-41.6) ng/ml (p = 0.053). β-hydroxybutyrate levels were significantly increased and triglycerides and free T3 hormone levels significantly reduced by the PL intervention. This pilot study shows that adoption of a PL intervention during curative radiotherapy of breast cancer patients is feasible and able to reduce fat mass. Daily outdoor activity could eliminate vitamin D deficiency (vitamin D < 20 ng/ml). Future studies are needed to confirm these findings.

Molecular Links between Central Obesity and Breast Cancer

Worldwide, breast cancer (BC) is the most common malignancy in women, in regard to incidence and mortality. In recent years, the negative role of obesity during BC development and progression has been made abundantly clear in several studies. However, the distribution of body fat may be more important to analyze than the overall body weight. In our review of literature, we reported some key findings regarding the role of obesity in BC development, but focused more on central adiposity. Firstly, the adipose microenvironment in obese people bears many similarities with the tumor microenvironment, in respect to associated cellular composition, chronic low-grade inflammation, and high ratio of reactive oxygen species to antioxidants. Secondly, the adipose tissue functions as an endocrine organ, which in obese people produces a high level of tumor-promoting hormones, such as leptin and estrogen, and a low level of the tumor suppressor hormone, adiponectin. As follows, in BC this leads to the activation of oncogenic signaling pathways: NFκB, JAK, STAT3, AKT. Moreover, overall obesity, but especially central obesity, promotes a systemic and local low grade chronic inflammation that further stimulates the increase of tumor-promoting oxidative stress. Lastly, there is a constant exchange of information between BC cells and adipocytes, mediated especially by extracellular vesicles, and which changes the transcription profile of both cell types to an oncogenic one with the help of regulatory non-coding RNAs.

World Cancer Research Fund International: Continuous Update Project-systematic literature review and meta-analysis of observational cohort studies on physical activity, sedentary behavior, adiposity, and weight change and breast cancer risk

PURPOSE

The purpose of the present study was to systematically review the complex associations between energy balance-related factors and breast cancer risk, for which previous evidence has suggested different associations in the life course of women and by hormone receptor (HR) status of the tumor.

METHODS

Relevant publications on adulthood physical activity, sedentary behavior, body mass index (BMI), waist and hip circumferences, waist-to-hip ratio, and weight change and pre- and postmenopausal breast cancer risk were identified in PubMed up to 30 April 2017. Random-effects meta-analyses were conducted to summarize the relative risks across studies.

RESULTS

One hundred and twenty-six observational cohort studies comprising over 22,900 premenopausal and 103,000 postmenopausal breast cancer cases were meta-analyzed. Higher physical activity was inversely associated with both pre- and postmenopausal breast cancers, whereas increased sitting time was positively associated with postmenopausal breast cancer. Although higher early adult BMI (ages 18-30 years) was inversely associated with pre- and postmenopausal breast cancers, adult weight gain and greater body adiposity increased breast cancer risk in postmenopausal women, and the increased risk was evident for HR+ but not HR- breast cancers, and among never but not current users of postmenopausal hormones. The evidence was less consistent in premenopausal women. There were no associations with adult weight gain, inverse associations with adult BMI (study baseline) and hip circumference, and non-significant associations with waist circumference and waist-to-hip ratio that were reverted to positive associations on average in studies accounting for BMI. No significant associations were observed for HR-defined premenopausal breast cancers.

CONCLUSION

Better understanding on the impact of these factors on pre- and postmenopausal breast cancers and their subtypes along the life course is needed.

Risk of Breast Cancer With Long-Term Use of Calcium Channel Blockers or Angiotensin-Converting Enzyme Inhibitors Among Older Women

Controversy exists about breast cancer risk associated with long-term use of calcium channel blockers (CCBs) or angiotensin-converting enzyme inhibitors (ACEis), respectively. Our objective in this study was to separately evaluate associations between duration of CCB or ACEi use and breast cancer in hypertensive women aged ≥55 years at 3 sites in the Kaiser Permanente health-care system (1997–2012). Exposures included CCB or ACEi use of 1–12 years’ duration, determined from pharmacy dispensings. Outcomes included invasive lobular or ductal carcinoma. Statistical methods included discrete-time survival analyses. The cohort included 19,674 (17.9%) CCB users and 90,078 (82.1%) ACEi users. Two percent (n = 397) of CCB users and 1.9% (n = 1,733) of ACEi users developed breast cancer. Compared with 1–<2 years of use, in adjusted analysis, there was no association between CCB use for 2–<12 years and breast cancer: All 95% confidence intervals included 1. Increasing duration of ACEi use was associated with reduced breast cancer risk: Compared with 1–<2 years of use, the adjusted hazard ratio was 0.76 (95% confidence interval: 0.63, 0.92) for 5–<6 years of use and 0.63 (95% confidence interval: 0.43, 0.93) for 9–<10 years of use. We conclude that among older women with hypertension, long-term CCB use does not increase breast cancer risk and long-term treatment with ACEis may confer protection against breast cancer.

Insulin, insulin receptors, and cancer

Insulin is a major regulator of cell metabolism but, in addition, is also a growth factor. Insulin effects in target cells are mediated by the insulin receptor (IR), a transmembrane protein with enzymatic (tyrosine kinase) activity. The insulin receptor, however, is represented by a heterogeneous family of proteins, including two different IR isoforms and also hybrid receptors resulting from the IR hemireceptor combination with a hemireceptor of the cognate IGF-1 receptor. These different receptors may bind insulin and its analogs with different affinity and produce different biologic effects. Since many years, it is known that many cancer cells require insulin for optimal in vitro growth. Recent data indicate that: (1) insulin stimulates growth mainly via its own receptor and not the IGF-1 receptor; (2) in many cancer cells, the IR is overexpressed and the A isoform, which has a predominant mitogenic effect, is more represented than the B isoform. These characteristics provide a selective growth advantage to malignant cells when exposed to insulin. For this reason, all conditions of hyperinsulinemia, both endogenous (prediabetes, metabolic syndrome, obesity, type 2 diabetes before pancreas exhaustion and polycystic ovary syndrome) and exogenous (type 1 diabetes) will increase the risk of cancer. Cancer-related mortality is also increased in patients exposed to hyperinsulinemia but other factors, related to the different diseases, may also contribute. The complexity of the diseases associated with hyperinsulinemia and their therapies does not allow a precise evaluation of the cancer-promoting effect of hyperinsulinemia, but its detrimental effect on cancer incidence and mortality is well documented.

Effect of oncological treatment on serum adipocytokine levels in patients with stage II-III breast cancer

Adipose tissue-derived hormones (adipocytokines), such as adiponectin, leptin, resistin and visfatin, and the pancreatic hormone insulin, have been suggested to play a role in carcinogenesis. we therefore hypothesized that the oncological treatment of breast cancer may alter the serum levels of these adipocytokines and insulin. In this study, we aimed to compare the serum levels of adipocytokines and insulin between the pre- and post-treatment period in patients with breast cancer. In this prospective study, 20 consecutive patients with stage II and III breast cancer underwent breast-conserving surgery or total mastectomy and/or axillary dissection. The patients received adjuvant chemotherapy and radiotherapy, if necessary. Blood samples were obtained during the preoperative period and postoperatively after completion of the adjuvant therapy. There was no statistically significant difference between the pre- and post-treatment levels of visfatin, adiponectin and leptin. However, the serum insulin and resistin levels and insulin resistance were found to be statistically significantly increased following treatment (P<0.05). Post-treatment resistin levels were positively correlated with insulin resistance (r=0.45, P<0.05). Therefore, oncological treatment of stage II and III breast cancer did not affect visfatin, adiponectin and leptin levels, but statistically significantly increased resistin levels and insulin resistance. In addition, the post-treatment resistin levels were positively correlated with insulin resistance, suggesting that resistin may be involved in the development of insulin resistance in breast cancer patients following treatment.

Body size throughout adult life influences postmenopausal breast cancer risk among hispanic women: the breast cancer health disparities study

BACKGROUND

Few studies have assessed the association of body size with postmenopausal breast cancer risk in Hispanic women. Findings are inconsistent and appear to contradict those reported for non-Hispanic white (NHW) women.

METHODS

We pooled interview and anthropometric data for 2,023 Hispanic and 2,384 NHW women from two U.S. population-based case-control studies. Using logistic regression analysis, we examined associations of overall and abdominal adiposity with risk of postmenopausal breast cancer defined by estrogen receptor (ER) and progesterone receptor (PR) status.

RESULTS

Weight gain was associated with increased risk of ER(+)PR(+) breast cancer in Hispanics not currently using menopausal hormone therapy (HT), but only among those with a low young-adult body mass index (BMI). In the subset of Hispanics with data on genetic ancestry, the association with weight gain was limited to women with lower Indigenous American ancestry. Young-adult BMI was inversely associated with both ER(+)PR(+) and ER(-)PR(-) breast cancers for both ethnicities combined, with similar, although nonsignificant, inverse trends in Hispanics and NHWs. Among all Hispanics, regardless of HT use, height was associated with risk of ER(-)PR(-) breast cancer and hip circumference with risk of breast cancer overall.

CONCLUSIONS

Body size throughout adult life is associated with breast cancer risk among postmenopausal Hispanic women, as has been reported for NHW women. Associations were specific for breast cancer subtypes defined by hormone receptor status.

IMPACT

Avoiding weight gain and maintaining a healthy weight are important strategies to reduce the risk of postmenopausal ER(+)PR(+) breast cancer, the most common breast cancer subtype.

Clinical studies examining the impact of obesity on breast cancer risk and prognosis

Obesity is associated with an increased risk of breast cancer, and increased risk of recurrence in women who develop breast cancer. Evidence suggests that the risk of estrogen-receptor (ER)-positive breast cancer is increased in obese postmenopausal women, whereas in premenopausal women the risk of triple negative breast cancer is increased. Nonetheless, the presence of obesity at diagnosis, and possibly weight gain after diagnosis, may independently contribute to an individual's risk of recurrence of both pre- and postmenopausal breast cancer. Factors associated with adiposity that are likely contributing factors include hyperinsulinemia, inflammation, and relative hyperestrogenemia. Some studies suggest that some aromatase inhibitors may be less effective in obese women than lean women. Clinical trials have evaluated pharmacologic (eg, metformin) and dietary/lifestyle interventions to reduce breast cancer recurrence, although these interventions have not been tested in obese women who may be most likely to benefit from them. Further research is required in order to identify adiposity-associated factors driving recurrence, and design clinical trials to specifically test interventions in obese women at highest risk of recurrence.

Glucose promotes breast cancer aggression and reduces metformin efficacy

Metformin treatment has been associated with a decrease in breast cancer risk and improved survival. Metformin induces complex cellular changes, resulting in decreased tumor cell proliferation, reduction of stem cells, and apoptosis. Using a carcinogen-induced rodent model of mammary tumorigenesis, we recently demonstrated that overfeeding in obese animals is associated with a 50% increase in tumor glucose uptake, increased proliferation, and tumor cell reprogramming to an "aggressive" metabolic state. Metformin significantly inhibited these pro-tumorigenic effects. We hypothesized that a dynamic relationship exists between chronic energy excess (glucose by dose) and metformin efficacy/action. Media glucose concentrations above 5 mmol/L was associated with significant increase in breast cancer cell proliferation, clonogenicity, motility, upregulation/activation of pro-oncogenic signaling, and reduction in apoptosis. These effects were most significant in triple-negative breast cancer (TNBC) cell lines. High-glucose conditions (10 mmol/L or above) significantly abrogated the effects of metformin. Mechanisms of metformin action at normal vs. high glucose overlapped but were not identical; for example, metformin reduced IGF-1R expression in both the HER2+ SK-BR-3 and TNBC MDA-MB-468 cell lines more significantly at 5, as compared with 10 mmol/L glucose. Significant changes in gene profiles related to apoptosis, cellular processes, metabolic processes, and cell proliferation occurred with metformin treatment in cells grown at 5 mmol/L glucose, whereas under high-glucose conditions, metformin did not significantly increase apoptotic/cellular death genes. These data indicate that failure to maintain glucose homeostasis may promote a more aggressive breast cancer phenotype and alter metformin efficacy and mechanisms of action.

Association of breast cancer subtypes and body mass index

AIMS AND BACKGROUND

Breast cancer is a heterogeneous disease with various pathological and molecular subtypes. This study aims to determine the association between BMI and the distribution of breast cancer subtypes defined by estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor (HER2/neu) expression in pre- and postmenopausal breast cancers.

METHODS AND STUDY DESIGN

A total of 1847 female breast cancer patients were involved. After the exclusion of 457 patients due to missing subtype information (n = 400) or benign histology (n = 57), 1390 were included in the analyses. The histological type of the tumor, ER and PR expression, HER2/neu with immunohistochemistry and HER2/neu gene evaluation with interphase fluorescence in situ hybridization (if necessary), age, body weight, height and menopausal status at diagnosis were investigated retrospectively. The patients were stratified as having a normal body weight if BMI was ≤24.9 kg/m², as being overweight if BMI was between 25.0 and 29.9 kg/m², and as being obese if BMI was ≥30.0 kg/m².

RESULTS

Median BMI was 28.7 kg/m² (17.6-55.6) in the postmenopausal and 25.6 kg/m² (16.4-51.1) in the premenopausal group (P <0.001). BMI at diagnosis did not differ significantly between the molecular subtypes (P = 0.12). Distribution of BMI strata was similar between the molecular subtypes both in pre- and postmenopausal breast cancer (P = 0.24 and P = 0.99, respectively). Premenopausal women with a BMI of ≥25.0 kg/m² showed a tendency towards ER- tumors when compared to premenopausal women with a BMI of <25.0 kg/m² (P = 0.009).

CONCLUSIONS

The risk of specific breast cancer subtypes may not be associated with BMI in pre- and postmenopausal breast cancer. However, obesity might be related to an increased risk of premenopausal hormone receptor-negative breast cancer. Further studies are needed for clarification of the probable mechanisms in the pathogenesis of premenopausal hormone receptor-negative breast cancer.

Homeostasis model assessment to detect insulin resistance and identify patients at high risk of breast cancer development: National Cancer Institute of Naples experience

BACKGROUND

Metabolic Syndrome (MS) has been correlated to breast carcinogenesis. MS is common in the general population (34%) and increases with age and body mass index. Although the link between obesity, MS and hormone related cancer incidence is now widely recognized, the molecular mechanisms at the basis of such increase are still poorly characterized. A crucial role is supposed to be played by the altered insulin signalling, occurring in obese patients, which fuels cancer cell growth, proliferation and survival. Therefore we focused specifically on insulin resistance to investigate clinically the potential role of insulin in breast carcinogenesis.

METHODS

975 patients were enrolled and the association between MS, insulin resistance, and breast cancer was evaluated. Women were stratified by age and menopausal status. Insulin resistance was measured through the Homeostasis Model Assessment score (HOMA-IR). The cut off value to define insulin resistance was HOMA-IR ≥ 2.50.

RESULTS

Higher prevalence of MS (35%) was found among postmenopausal women with breast cancer compared to postmenopausal healthy women (19%) [OR 2.16]. A broad range of BMI spanning 19-48 Kg/m2 was calculated. Both cases and controls were characterized by BMI ≥ 25 Kg/m2 (58% of cases compared to 61% of controls). Waist circumference >88 cm was measured in 53% of cases - OR 1.58- (95% CI 0.8-2.8) and in 46% of controls. Hyperinsulinemia was detected in 7% of cases - OR 2.14 (95% CI 1.78-2.99) and only in 3% of controls. HOMA-IR score was elevated in 49% of cases compared to 34% of controls [OR 1.86], suggesting that insulin resistance can nearly double the risk of breast cancer development. Interestingly 61% of women operated for breast cancer (cases) with HOMA-IR ≥ 2.5 presented subclinical insulin resistance with fasting plasma glucose levels and fasting plasma insulin levels in the normal range. Both android fat distribution and insulin resistance correlated to MS in the subgroup of postmenopausal women affected by breast cancer.

CONCLUSIONS

Our results further support the hypothesis that MS, in particular insulin resistance and abdominal fat, can be considered as risk factors for developing breast cancer after menopause. We suggest that HOMA-IR, rather than fasting plasma glucose and fasting plasma insulin levels alone, could be a valuable tool to identify patients with subclinical insulin resistance, which could be relevant for primary prevention and for high risk patient screening.

Differential impact of body mass index and its change on the risk of breast cancer by molecular subtype: A case-control study in Japanese women

Body mass index (BMI) is an independent risk factor for luminal-type breast cancer in Western populations. However, it is unclear whether the impact of BMI differs according to breast cancer subtype in Japanese populations. We conducted a case–control study with 715 cases and 1430 age- and menopausal status-matched controls to evaluate the associations of BMI and its change (from age 20 years to the current age) with breast cancer risk. We applied conditional logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Tumor subtypes were divided into four subtypes, namely the luminal, luminal/HER2, HER2-rich, and triple-negative subtypes. Current BMI and BMI change were positively associated with postmenopausal breast cancer risk. On stratified analysis by tumor subtype, we observed associations between current BMI and BMI change and postmenopausal breast cancer risk for the luminal subtype, with OR for each 1 kg/m² increase in current BMI of 1.14 (95% CI: 1.07 - 1.20) and the corresponding OR of BMI change of 1.16 (1.09 - 1.23) (each P_trend < 0.001). Additionally, we found the same tendency for the triple-negative subtype, with the OR for a 1 kg/m² increase in current BMI of 1.21 (1.05 - 1.39) and that for BMI change of 1.18 (1.02 - 1.36) (P_trend was 0.008 and 0.024, respectively). In premenopausal women, a suggestive inverse association was observed between BMI change and breast cancer risk for the luminal subtype only, with OR of BMI change of 0.93 (0.87 - 1.00, P_trend = 0.054). No association was seen between BMI at age 20 years and risk of any tumor subtype. In conclusion, BMI and its change are associated with the risk of both luminal and triple-negative breast cancer among postmenopausal Japanese women. These findings suggest the etiological heterogeneity of breast cancer among tumor subtypes.

Prognostic effect of circulating adiponectin in a randomized 2 x 2 trial of low-dose tamoxifen and fenretinide in premenopausal women at risk for breast cancer

PURPOSE

Adipokines are linked to obesity and insulin sensitivity and have recently been related to breast cancer risk and prognosis. We investigated the associations of plasma leptin and adiponectin with mammographic density and disease status and assessed their prognostic effect on recurrence-free survival in premenopausal women at risk for breast cancer.

PATIENTS AND METHODS

We measured circulating lipids, insulin-like growth factor 1, glucose, insulin and insulin sensitivity (calculated by homeostasis model assessment [HOMA] index), leptin, adiponectin, and leptin-to-adiponectin ratio in 235 premenopausal women with pT1mic/pT1a breast cancer (n = 21), intraepithelial neoplasia (n = 160), or 5-year Gail risk of 1.3% or greater (n = 54) who participated in a 2 × 2 trial of low-dose tamoxifen, fenretinide, both agents, or placebo over a 2-year period.

RESULTS

At baseline, adiponectin levels were directly associated with mammographic density and HDL cholesterol and negatively associated with leptin, leptin-to-adiponectin ratio, body mass index (BMI), and HOMA index. Median adiponectin levels were lower in affected than in unaffected women (P = .006). After a median of 7.2 years and total of 57 breast neoplastic events, there was a 12% reduction in the risk of breast neoplastic events per unit increase of adiponectin (adjusted hazard ratio, 0.88; 95% CI, 0.81 to 0.96; P = .03). There was no interaction between treatment and adiponectin levels.

CONCLUSION

Low adiponectin levels are associated with a history of prior intraepithelial neoplasia or pT1mic/pT1a breast cancer and higher risk of second breast neoplastic events in premenopausal women. The associations are independent of BMI, mammographic density, and treatment. Our findings support the role of adiponectin as a potential target for premenopausal breast cancer prevention and treatment.

Risk factors by molecular subtypes of breast cancer across a population-based study of women 56 years or younger

Differences in incidence, prognosis, and treatment response suggest gene expression patterns may discern breast cancer subtypes with unique risk factor profiles; however, previous results were based predominantly on older women. In this study, we examined similar relationships in women ≤ 56 years, classified by immunohistochemical staining for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2 for 890 breast cancer cases and 3,432 frequency-matched population-based controls. Odds ratios (OR) and 95% confidence intervals (CI) for tumor subtypes were calculated using multivariate polytomous regression models. A total of 455 (51.1%) tumors were considered luminal A, 72 (8.1%) luminal B, 117 (13.1%) non-luminal HER-2/neu+, and 246 (27.6%) triple negative. Triple negative tumors were associated with breast feeding duration (per 6 months: OR = 0.76, 95% CI 0.64-0.90). Among premenopausal women, increasing body size was more strongly associated with luminal B (OR = 1.73, 95% CI 1.07-2.77) and triple negative tumors (OR = 1.67, 95% CI 1.22-2.28). A history of benign breast disease was associated only with increased risk of luminal A tumors (OR = 1.89, 95% CI 1.43-2.50). A family history of breast cancer was a risk factor for luminal A tumors (OR = 1.93, 95% CI 1.38-2.70) regardless of age, and triple negative tumors with higher risks for women <45 (OR = 5.02, 95% CI 2.82-8.92; P for age interaction = 0.005). We found that little-to-no breastfeeding and high BMI were associated with increased risk of triple negative breast cancer. That some risk factors differ by molecular subtypes suggests etiologic heterogeneity in breast carcinogenesis among young women.

A community-based approach to translational research addressing breast cancer disparities

Disparities in breast cancer survival rates suggest that biological processes contribute. Translational research addressing health disparities would benefit from using a community-based participatory approach (CBPR) to examine biological processes commonly seen as the proximal causes of illness as well as behavioral and social-ecological "causes of the causes" within an integrated conceptual framework. This paper describes a CBPR study that explored perceptions regarding breast cancer relevant behaviors, and the application of the study's results to develop translational research. Data from eight focus groups of African American (n = 29) and Caucasian women (n = 27) were analyzed, using the framework of the social-ecological model. Nutrition and physical activity were valued over screening and research participation. Treatment of illness was emphasized over prevention. Women's perspectives are presented within a framework that facilitated the collaborative development of translational research to examine associations among biological, behavioral, and societal processes contributing to disparities.

Body size, physical activity, and risk of triple-negative and estrogen receptor-positive breast cancer

BACKGROUND

Triple-negative breast cancer, characterized by a lack of hormone receptor and HER2 expression, is associated with a particularly poor prognosis. Focusing on potentially modifiable breast cancer risk factors, we examined the relationship between body size, physical activity, and triple-negative disease risk.

METHODS

Using data from 155,723 women enrolled in the Women's Health Initiative (median follow-up, 7.9 years), we assessed associations between baseline body mass index (BMI), BMI in earlier adulthood, waist and hip circumference, waist-hip ratio, recreational physical activity, and risk of triple-negative (n=307) and estrogen receptor-positive (ER+, n=2,610) breast cancers.

RESULTS

Women in the highest versus lowest BMI quartile had 1.35-fold (95% CI, 0.92-1.99) and 1.39-fold (95% CI, 1.22-1.58) increased risks of triple-negative and ER+ breast cancers, respectively. Waist and hip circumferences were positively associated with risk of ER+ breast cancer (Ptrend=0.01 for both measures) but were not associated with triple-negative breast cancer. Compared with women who reported no recreational physical activity, women in the highest activity tertile had similarly lower risks of triple-negative and ER+ breast cancers (HR=0.77; 95% CI, 0.51-1.13; and HR=0.85; 95% CI, 0.74-0.98, respectively).

CONCLUSIONS

Despite biological and clinical differences, triple-negative and ER+ breast cancers are similarly associated with BMI and recreational physical activity in postmenopausal women. The biological mechanisms underlying these similarities are uncertain and these modest associations require further investigation.

IMPACT

If confirmed, these results suggest potential ways postmenopausal women might modify their risk of both ER+ and triple-negative breast cancers.

The cholesterol metabolite 25-hydroxycholesterol activates estrogen receptor α-mediated signaling in cancer cells and in cardiomyocytes

BACKGROUND

The hydroxylated derivatives of cholesterol, such as the oxysterols, play important roles in lipid metabolism. In particular, 25-hydroxycholesterol (25 HC) has been implicated in a variety of metabolic events including cholesterol homeostasis and atherosclerosis. 25 HC is detectable in human plasma after ingestion of a meal rich in oxysterols and following a dietary cholesterol challenge. In addition, the levels of oxysterols, including 25 HC, have been found to be elevated in hypercholesterolemic serum.

METHODOLOGY/PRINCIPAL FINDINGS

Here, we demonstrate that the estrogen receptor (ER) α mediates gene expression changes and growth responses induced by 25 HC in breast and ovarian cancer cells. Moreover, 25 HC exhibits the ERα-dependent ability like 17 β-estradiol (E2) to inhibit the up-regulation of HIF-1α and connective tissue growth factor by hypoxic conditions in cardiomyocytes and rat heart preparations and to prevent the hypoxia-induced apoptosis.

CONCLUSIONS/SIGNIFICANCE

The estrogen action exerted by 25 HC may be considered as an additional factor involved in the progression of breast and ovarian tumors. Moreover, the estrogen-like activity of 25 HC elicited in the cardiovascular system may play a role against hypoxic environments.

Endocrine disruptors and obesity: an examination of selected persistent organic pollutants in the NHANES 1999-2002 data

Recent evidence suggests that endocrine disrupting chemicals (EDCs) may cause perturbations in endogenous hormonal regulation that predispose to weight gain. Using data from NHANES (1999-2002), we investigated the association between body mass index (BMI), waist circumference (WC) and selected persistent organic pollutants (POPs) via multiple linear regressions. Consistent interaction was found between gender, ln oxychlordane and ln p,p' DDT. Also, we found an association between WC and ln oxychlordane and ln hpcdd in subjects with detectable levels of POPs, whereas an association between WC and ln p,p' DDT was observed in all subjects. Furthermore, ln Ocdd showed an increase with higher WC and BMI, whereas, ln trans-nonachlor decreased with higher BMI. Hence, BMI and WC are associated with POPs levels, making the chemicals plausible contributors to the obesity epidemic.

A high protein moderate carbohydrate diet fed at discrete meals reduces early progression of N-methyl-N-nitrosourea-induced breast tumorigenesis in rats

Breast cancer is the most prevalent cancer in American women. Dietary factors are thought to have a strong influence on breast cancer incidence. This study utilized a meal-feeding protocol with female Sprague-Dawley rats to evaluate effects of two ratios of carbohydrate:protein on promotion and early progression of breast tissue carcinomas. Mammary tumors were induced by N-methyl-N-nitrosourea (MNU) at 52 d of age. Post-induction, animals were assigned to consume either a low protein high carbohydrate diet (LPHC; 15% and 60% of energy, respectively) or a high protein moderate carbohydrate diet (HPMC; 35% and 40% of energy, respectively) for 10 wk. Animals were fed 3 meals/day to mimic human absorption and metabolism patterns. The rate of palpable tumor incidence was reduced in HPMC relative to LPHC (12.9 ± 1.4%/wk vs. 18.2 ± 1.3%/wk). At 3 wk, post-prandial serum insulin was larger in the LPHC relative to HPMC (+136.4 ± 33.1 pmol/L vs. +38.1 ± 23.4 pmol/L), while at 10 wk there was a trend for post-prandial IGF-I to be increased in HPMC (P = 0.055). There were no differences in tumor latency, tumor surface area, or cumulative tumor mass between diet groups. The present study provides evidence that reducing the dietary carbohydrate:protein ratio attenuates the development of mammary tumors. These findings are consistent with reduced post-prandial insulin release potentially diminishing the proliferative environment required for breast cancer tumors to progress.

Association of Obesity and Breast Cancer Risk: The Role of Estrogen, Tumor Necrosis Factor-alpha, and Adiponectin as Risk factors (preliminary study)

BACKGROUND: Breast cancer is the most frequent cancer diagnosed among women. Many factors influence the carcinogenesis of breast cancer. The aim of this study to analyze the role of obesity (waist circumference and body mass index), serum Estradiol levels, TNF-α, and Adiponectin in the occurrence of breast cancer.METHODS: This was observational study with casecontrol design. Eleven breast cancer patients as cases and twelve Fibroadenoma Mammae (FAM) patients as controls were analyzed. The serum Estrogen, TNF-α and Adiponectin were examined in their association with breast cancer risk.RESULTS: Women with breast tumor and waist circumference > 80 cm have significantly higher breast cancer risk than women with breast tumor and waist circumference <80 cm (OR 8.75; 95% CI=1.24-61.88; p=0.029). Women with breast tumor and higher serum TNF-α levels (>2.30 pg/ml) have higher breast cancer risk (19.25 times) than women with breast tumor and have lower serum TNF-α levels (95% CI=1.77-209.55, p=0.015). Whereas, women with breast tumor and lower Adiponectin/TNF-α ratio (< 2.13) have higher breast cancer risk (22.5 times) than women with breast tumor and higher Adiponectin/TNF-α (95% CI=2.60-194.51; p=0.005).CONCLUSION: These results suggest that high concentration of serum TNF-α, waist circumference >80 cm and low Adiponectin/TNF-α ratio in women with breast tumor are significantly associated with an increased risk for breast cancer.KEYWORDS: Obesity, breast cancer, adiponectin/TNF-α ratio

IKKbeta mediates cell shape-induced aromatase expression and estrogen biosynthesis in adipose stromal cells

Aromatase (Cyp19) is a key enzyme in estrogen biosynthesis and an important target in breast cancer therapy. Within tumor microenvironment, tumor cells stimulate aromatase expression in adipose stromal cells (ASCs), which in turn promotes estrogen-dependent growth of estrogen receptor (ER)-positive tumor cells. However, it is not clear how aromatase transcription and estrogen biosynthesis are regulated in ASCs under a precancerous condition. Here we demonstrate that cell shape change alone is sufficient to induce aromatase expression in primary ASCs from cancer-free individuals. The activation of aromatase transcription is mediated by IkappaB kinase-beta (IKKbeta), a kinase previously known for its cancer-promoting activity in tumor cells. Activation of IKKbeta leads to elevated expression of transcription factor CCAAT/enhancer-binding protein-beta (C/EBPbeta), which binds to and stimulates two breast cancer-associated promoters of the aromatase gene. We also show that shape-induced estrogen production in ASCs can stimulate estrogen-dependent transcription in ER-positive breast tumor cells. We suggest that IKKbeta-dependent aromatase induction due to changes in cellular architecture in adipose tissue may contribute to the breast cancer risks associated with high mammagraphic density and obesity.

Fatty acid uptake by breast cancer cells (MDA-MB-231): effects of insulin, leptin, adiponectin, and TNFalpha

In order to exert metabolic effects, fatty acids must be taken up by cells and metabolize effectively to different classes of cellular lipids (triacylglycerols, phospholipids, etc.) for incorporation into different cellular and intracellular compartments. Therefore, the main aim of the present study is to investigate the uptake and metabolism of fatty acids representing three different series of fatty acids such as oleic acid, 18:1n-9 (OA), arachidonic acid, 20:4n-6 (AA), and eicosapentaneoic acid, 20:5n-3 (EPA) by breast cancer cells, MDA-MB-231. Moreover, we investigated the effects of insulin and several adipokines on the fatty acid uptake by these cells as obesity and insulin resistance syndrome have been suggested to affect breast cancer risk. We report for the first time that AA was predominantly taken up by these cells compared with EPA and OA. Pre-incubation of these cells with TNFalpha stimulated most of the uptake of EPA (30%), whereas uptake of OA and AA was stimulated only 10-15% compared with the controls. Insulin, leptin, and adiponectin had no effect on fatty acid uptake by these cells. Together these results demonstrate that preferential uptake of AA in MDA-MB-231 cells, and the fatty acid uptake activity of these cells is influenced by TNFalpha.

Clinical Use of PPARgamma Ligands in Cancer

The role of PPARγ in adipocyte differentiation has fueled intense interest in the function of this steroid nuclear receptor for regulation of malignant cell growth and differentiation. Given the antiproliferative and differentiating effects of PPARγ ligands on liposarcoma cells, investigation of PPARγ expression and ligand activation in other solid tumors such as breast, colon, and prostate cancers ensued. The anticancer effects of PPARγ ligands in cell culture and rodent models of a multitude of tumor types suggest broad applicability of these agents to cancer therapy. This review focuses on the clinical use of PPARγ ligands, specifically the thiazolidinediones, for the treatment and prevention of cancer.

Putative environmental-endocrine disruptors and obesity: a review

PURPOSE OF REVIEW

There has been a substantial increase in the prevalence of obesity in the last several decades. Recent evidence suggests that endocrine-disrupting chemicals, for example halogenated aromatic hydrocarbons, may cause perturbations in endogenous hormonal regulation and alter other mechanisms involved in weight homeostasis, which may lead to weight gain by increased volume of adipose tissue. Synthetic chemicals derived from industrial processes are suspected to play a contributory role. Yet of the approximately 70,000 documented synthetic chemicals, few have been examined to determine their effects on the endocrine system.

RECENT FINDINGS

The present study examines prior laboratory, epidemiological and experimental research findings. Data demonstrate migration of endocrine disruptors in the environment and are beginning to catalogue their effects on adiposity. We present postulated relationships between these chemicals, their mechanisms of action, and the obesity epidemic.

SUMMARY

Endocrine disruptors may adversely impact human and environmental health by altering the physiological control mechanism. Obesity, which is known to increase medical costs and reduce quality and length of life, may be increasing as a function of endocrine disruptor exposure. This merits concern among scientists and public health officials and warrants additional vigorous research in this area.

Adiponectin stimulates Wnt inhibitory factor-1 expression through epigenetic regulations involving the transcription factor specificity protein 1

Adiponectin (ADN) is an adipokine possessing growth inhibitory activities against various types of cancer cells. Our previous results demonstrated that ADN could impede Wnt/beta-catenin-signaling pathways in MDA-MB-231 human breast carcinoma cells [Wang,Y. et al. (2006) Adiponectin modulates the glycogen synthase kinase-3 beta/beta-catenin signaling pathway and attenuates mammary tumorigenesis of MDA-MB-231 cells in nude mice. Cancer Res., 66, 11462-11470]. Here, we extended our studies to elucidate the effects of ADN on regulating the expressions of Wnt inhibitory factor-1 (WIF1), a Wnt antagonist frequently silenced in human breast tumors. Our results showed that ADN time dependently stimulated WIF1 gene and protein expressions in MDA-MB-231 cells. Overexpression of WIF1 exerted similar inhibitory effects to those of ADN on cell proliferations, nuclear beta-catenin activities, cyclin D1 expressions and serum-induced phosphorylations of Akt and glycogen synthase kinase-3 beta. Blockage of WIF1 activities significantly attenuated the suppressive effects of ADN on MDA-MB-231 cell growth. Furthermore, our in vivo studies showed that both supplementation of recombinant ADN and adenovirus-mediated overexpression of this adipokine substantially enhanced WIF1 expressions in MDA-MB-231 tumors implanted in nude mice. More interestingly, we found that ADN could alleviate methylation of CpG islands located within the proximal promoter region of WIF1, possibly involving the specificity protein 1 (Sp1) transcription factor and its downstream target DNA methyltransferase 1 (DNMT1). Upon ADN treatment, the protein levels of both Sp1 and DNMT1 were significantly decreased. Using silencing RNA approaches, we confirmed that downregulation of Sp1 resulted in an increased expression of WIF1 and decreased methylation of WIF1 promoter. Taken together, these data suggest that ADN might elicit its antitumor activities at least partially through promoting WIF1 expressions.

Body size and risk of luminal, HER2-overexpressing, and triple-negative breast cancer in postmenopausal women

Although the clinical relevance of molecular subtypes of breast cancer has been documented, little is known about risk factors for different tumor subtypes, especially the HER2-overexpressing and the triple-negative subtypes that have poor prognoses. Obesity may be differentially related to the risk of different subtypes given the various potential mechanisms underlying its association with breast cancer. We pooled two population-based case-control studies of postmenopausal breast cancer for an analysis, including 1,447 controls and 1,008 luminal (hormone receptor positive), 39 HER2-overexpressing (hormone receptor negative, HER2 positive), and 77 triple-negative (hormone receptor and HER2 negative) cases. Associations between anthropometric factors and the risk of different breast cancer subtypes were evaluated using polytomous logistic regression. Among women not currently using menopausal hormone therapy, body mass index (BMI) and weight were associated with the risk of luminal tumors [odds ratio (OR) comparing highest versus lowest quartiles, 1.7; 95% confidence interval (95% CI), 1.2-2.4 and OR, 1.7; 95% CI, 1.2-2.4, respectively] and suggestively associated with risk of triple-negative tumors (OR, 2.7; 95% CI, 1.0-7.5 and OR, 5.1; 95% CI, 1.1-23.0, respectively). Neither BMI nor weight was associated with the risk of any tumor subtype among hormone therapy users. The positive relationship between BMI and luminal tumors among postmenopausal women not using hormone therapy is well characterized in the literature. Although our sample size was limited, body size may also be related to the risk of postmenopausal triple-negative breast cancer among nonusers of hormone therapy. Given the expanding obesity epidemic, the widespread cessation of hormone therapy use, and the poor prognosis of triple-negative tumors, this novel finding merits confirmation.

Estrogen-biosynthesis gene CYP17 and its interactions with reproductive, hormonal and lifestyle factors in breast cancer risk: results from the Long Island Breast Cancer Study Project

The genes that are involved in estrogen biosynthesis, cellular binding and metabolism may contribute to breast cancer susceptibility. We examined the effect of the CYP17 promoter T --> C polymorphism and its interactions with the reproductive history, exogenous hormone use and selected lifestyle risk factors on breast cancer risk among 1037 population-based incident cases and 1096 population-based controls in the Long Island Breast Cancer Study Project. Overall, there were no associations between the CYP17 genotype and breast cancer risk. Among postmenopausal women, the joint exposure to higher body mass index (BMI) and the variant C allele was associated with an increased risk of breast cancer [odds ratio (OR), 1.60; 95% confidence interval (CI), 1.15-2.22]. The joint exposure to the variant C allele and long-term use of hormone replacement therapy (HRT) (>51 months) was related to an increased risk of breast cancer (OR, 1.51; 95% CI, 0.99-2.31) especially estrogen receptor-positive, progesterone receptor-positive breast cancer (OR, 1.87; 95% CI, 1.08-3.25). Among the control population, the CYP17 variant C allele was inversely associated with long-term use of postmenopausal HRT and a higher BMI in postmenopausal women. In conclusion, the findings suggest that the CYP17 variant C allele may increase breast cancer risk in conjunction with long-term HRT use and high BMI in postmenopausal women.

Weight gain prior to diagnosis and survival from breast cancer

BACKGROUND

To examine the effects of prediagnostic obesity and weight gain throughout the life course on survival after a breast cancer diagnosis, we conducted a follow-up study among a population-based sample of women diagnosed with first, primary invasive, and in situ breast cancer between 1996 and 1997 (n = 1,508).

METHODS

In-person interviews were conducted shortly after diagnosis to obtain information on height and weight at each decade of life from age 20 years until 1 year before diagnosis. Patients were followed to determine all-cause (n = 196) and breast cancer-specific (n = 127) mortality through December 31, 2002.

RESULTS

In multivariate Cox proportional hazards models, obese women had increased mortality due to breast cancer compared with ideal weight women among those who were premenopausal at diagnosis [hazard ratio (HR), 2.85; 95% confidence interval (95% CI), 1.30-6.23] and postmenopausal at diagnosis (HR, 1.91; 95% CI, 1.06-3.46). Among women diagnosed with premenopausal breast cancer, those who gained >16 kg between age 20 years and 1 year before diagnosis, compared with those whose weight remained stable (+/-3 kg), had more than a 2-fold elevation in all-cause (HR, 2.45; 95% CI, 0.96-6.27) and breast cancer-specific mortality (HR, 2.09; 95% CI, 0.80-5.48). Women diagnosed with postmenopausal breast cancer who gained more than 12.7 kg after age of 50 years up to the year before diagnosis had a 2- to 3-fold increased risk of death due to all-causes (HR, 2.69; 95% CI, 1.63-4.43) and breast cancer (HR, 2.95; 95% CI, 1.36-6.43).

CONCLUSIONS

These results indicate that high levels of prediagnostic weight and substantial weight gain throughout life can decrease survival in premenopausal and postmenopausal breast cancer patients.

Waist circumference values are increasing beyond those expected from BMI increases

OBJECTIVE

The objective of this investigation was to examine the relationship between BMI and waist circumference (WC) by gender and race subgroups from U.S. population-based data from 1959 to 2004 and to investigate the trend in WC over calendar time.

RESEARCH METHODS AND PROCEDURES

Demographic and anthropometric cross-sectional data on 30,730 participants 18 to 79 years old across five national surveys were included. We regressed WC on BMI while controlling for age in each time period for blacks and whites by gender.

RESULTS

The relationship between BMI and WC as characterized by the slope of the linear regression of WC on BMI does not seem to be changing significantly over time. A small (range, 0.08 to 0.27 cm/yr) increase in WC over time was observed.

DISCUSSION

The implications of these findings for public health and for understanding any extant changes in the BMI-mortality rate relationship remain to be elucidated.

27-hydroxycholesterol is an endogenous selective estrogen receptor modulator

Selective estrogen receptor (ER) modulators (SERMs) are ER ligands whose relative agonist/antagonist activities vary in a cell- and promoter-dependent manner. The molecular basis underlying this selectivity can be attributed to the ability of these ligands to induce distinct alterations in ER structure leading to differential recruitment of coactivators and corepressors. Whether SERM activity is restricted to synthetic ligands or whether molecules exist in vivo that function in an analogous manner remains unresolved. However, the recent observation that oxysterols bind ER and antagonize the actions of 17beta-estradiol (E2) on the vascular wall suggests that this class of ligands may possess SERM activity. We demonstrate here that 27-hydroxycholesterol (27HC), the most prevalent oxysterol in circulation, functions as a SERM, the efficacy of which varies when assessed on different endpoints. Importantly, 27HC positively regulates both gene transcription and cell proliferation in cellular models of breast cancer. Using combinatorial peptide phage display, we have determined that 27HC induces a unique conformational change in both ERalpha and ERbeta, distinguishing it from E2 and other SERMs. Thus, as with other ER ligands, it appears that the unique pharmacological activity of 27HC relates to its ability to impact ER structure and modulate cofactor recruitment. Cumulatively, these data indicate that 27HC is an endogenous SERM with partial agonist activity in breast cancer cells and suggest that it may influence the pathology of breast cancer. Moreover, given the product-precursor relationship between 27HC and cholesterol, our findings have implications with respect to breast cancer risk in obese/hypercholesteremic individuals.

Relation between insulin resistance and breast cancer among Chilean women

PURPOSE

In Chile, diabetes and breast cancer are important public health problems. The association between insulin resistance and breast cancer, however, remains largely unexplored.

METHODS

We conducted a case-control study to assess the relationship of insulin resistance (IR) and breast cancer in Chilean premenopausal and postmenopausal women. We compared 170 women, 33 to 86 years old, with incident breast cancer and 170 normal mammography controls, matched by 5-year age interval. Plasmatic insulin and glucose were measured and IR was calculated by the homeostasis model assessment method. Anthropometric measurements and sociodemographic and behavioral data were also collected. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by multivariable conditional logistic regression.

RESULTS

IR was independently associated with breast cancer in postmenopausal women (OR = 2.70, 95%CI = 1.10-6.63), but not in premenopausal women (OR = 0.84, 95%CI = 0.20-3.52). Obesity was not associated with breast cancer at any age (OR = 0.68, 95%CI = 0.39-1.20).

CONCLUSION

In this sample, IR increased the risk of breast cancer among postmenopausal women.

Pilot study of rosiglitazone therapy in women with breast cancer: effects of short-term therapy on tumor tissue and serum markers

PURPOSE

Peroxisome proliferator-activated receptor gamma (PPARgamma) is a steroid nuclear receptor that is activated by natural compounds such as specific fatty acids and synthetic drugs such as thiazolidinedione antidiabetic agents. Expressed in normal and malignant mammary epithelial cells, activation of PPARgamma is associated with antiproliferative effects on human breast cancer cells in preclinical studies. The purpose of this study was to test the hypothesis that PPARgamma ligand therapy might inhibit tumor growth and progression in human breast cancer.

EXPERIMENTAL DESIGN

We conducted a pilot trial of short-term (2-6 weeks) treatment with the thiazolidinedione rosiglitazone in 38 women with early-stage (T(is)-T(2), N(0-1), M(0)) breast cancer, administered between the time of diagnostic biopsy and definitive surgery.

RESULTS

Short-term treatment with rosiglitazone (8 mg/d) did not elicit significant effects on breast tumor cell proliferation using Ki67 expression as a measure of cell proliferation and surrogate marker of tumor growth and progression. In pretreatment tumors notable for nuclear expression of PPARgamma by immunohistochemistry, down-regulation of nuclear PPARgamma expression occurred following rosiglitazone administration (P = 0.005). No PPARG mutations were identified, and the incidence of P12A and H446H polymorphisms did not differ relative to U.S. controls (P = 0.5). Treatment with rosiglitazone resulted in increased serum adiponectin (P < 0.001), decreased insulin levels (P = 0.005), and increased insulin sensitivity (P = 0.004). Rosiglitazone was well tolerated without serious adverse events.

CONCLUSION

Our data indicate that short-term rosiglitazone therapy in early-stage breast cancer patients leads to local and systemic effects on PPARgamma signaling that may be relevant to breast cancer.

Tumor suppressor BRCA1 inhibits a breast cancer-associated promoter of the aromatase gene (CYP19) in human adipose stromal cells

Adipose tissue provides an important extragonadal source of estrogen. Obesity-associated elevation of estrogen production increases risk of breast cancer in postmenopausal women. Aromatase (CYP19), which converts androgen to estrogen, is a key enzyme in estrogen biosynthesis. In normal adipose tissue, transcription of the aromatase gene is initiated from a relatively weak adipose-specific promoter (I.4). However, in breast cancer, a switch of promoter utilization from I.4 to a strong ovary-specific promoter, PII, leads to increased aromatase expression and, hence, elevated estrogen production. Here, we report an intriguing relationship between the breast cancer susceptibility gene BRCA1 and aromatase expression in human adipose stromal cells (ASCs). Upon stimulation by phorbol ester or dexamethasone, increased aromatase expression in ASCs was accompanied by significant reduction of the BRCA1 level. In addition, adipogenesis-induced aromatase expression was also inversely correlated with BRCA1 abundance. Downregulation of BRCA1 expression in response to various stimuli was through distinct transcription or posttranscription mechanisms. Importantly, siRNA-mediated knockdown of BRCA1 led to specific activation of the breast cancer-associated PII promoter. Therefore, in addition to its well-characterized activities in breast epithelial cells, a role of BRCA1 in modulation of estrogen biosynthesis in ASCs may also contribute to its tissue-specific tumor suppressor function.

Identification of risk factors for breast cancer for women in istanbul

BACKGROUND

Breast cancer is the most common cancer type seen in women, accounts for 18% of all cancer types in women and the risk of a woman to get breast cancer during her life is 11%. These notified rates enable breast cancer to be defined as a preventable and if pre-diagnosed, a treatable cancer type, despite it was regarded as a terrifying type of cancer in the past.

OBJECTIVE

The aim of the study was to determine the lifestyle pattern of women without breast cancer in Istanbul.

METHOD

The study was carried out as a descriptive and cross-sectional study with 1000 women.

RESULTS

The majority of the women (29.7%) were in the 35-44 year old age group. Out of these 93.1% gave birth before the age of 30, 29.5% breastfed for 7-12 months, 65.8% started menarche between 13-15 years of age (mean of 13.3 years), 15.5% were in menopause and had entered menopause at a mean age of 46.5 years. Their mean body mass index was 24.3kg/m(2) and 24.5% of them preferred foods containing high fat content. The majority of the women (85.4%) did not participate in sports regularly. One third (30.3%) of the women had underwent Breast Self Examination. There was a positive family history of breast cancer for 12.1% of the women.

CONCLUSION

Sedentary lifestyles, lower Breast Self Examination and routine mammography rates and family histories of breast cancer were the risk factors that needed to be given priority for further action.

An association between a common variant (G972R) in the IRS-1 gene and sex hormone levels in post-menopausal breast cancer survivors

Insulin receptor substrate-1 (IRS-1) is a key downstream signaling molecule common to both the insulin and IGF signaling pathways that can interact with the estrogen pathway to regulate breast cell growth. We investigated whether a putative functional variant for IRS-1 (G972R) influences circulating levels of sex hormones, sex hormone binding globulin (SHBG), C-peptide, and insulin-like growth factor 1 (IGF-1) levels among post-menopausal African-American and non-Hispanic white breast cancer patients enrolled in the Health, Eating, Activity, and Lifestyle (HEAL) Study. Circulating levels of sex hormones and growth factors can influence breast cancer recurrence and survival. Serum estrone, estradiol, testosterone, SHBG, IGF-1 and C-peptide were measured in 468 patients at 30+ months post diagnosis. Non-protein bound hormone levels (free estradiol, free testosterone) were calculated. In African-American patients, the IRS-1 variant was associated with increased serum levels of estrone (p = 0.02), free estradiol (p = 0.04), total testosterone (p = 0.04), free testosterone (p = 0.006) and decreased levels of sex hormone-binding globulin (p = 0.02). No association was present for white patients. Our findings provide suggestive evidence that IRS-1 G972R variant may be associated with circulating levels of sex hormones and SHBG in African American breast cancer survivors.

Association of esophageal adenocarcinoma with other subsequent primary cancers

PURPOSE

Esophageal adenocarcinoma shares risk factors such as obesity and smoking with other common cancers. The association of esophageal adenocarcinoma with other primary cancers has not been systematically evaluated. The authors used the Surveillance, Epidemiology and End-Results database of the National Cancer Institute to explore the association of esophageal adenocarcinoma with other primary cancers.

PATIENTS AND METHODS

All adult patients with esophageal cancers, both adenocarcinoma and squamous cell carcinoma diagnosed between 1973 and 2001, were identified from the Surveillance, Epidemiology, and End-Results database, and standardized incidence rates were calculated for all subsequent primary cancers in these patients. The analysis was reversed to estimate the standardized incidence rate for subsequent primary esophageal cancer after a first primary cancer.

RESULTS

In comparison with a standard population, patients with esophageal adenocarcinoma were at higher risk for the development of another subsequent cancer, specifically, cancers of the oral cavity and pharynx, lung and bronchus, and kidney and renal pelvis, and adenocarcinoma of the colon/rectum and pancreas. With squamous cell esophageal cancer, there was an association with tobacco-related cancers such as those of the oral cavity and pharynx, the lung and bronchus, and the breast. There was either no association or even a negative association of esophageal adenocarcinoma with other obesity-related cancers such as breast, uterine, and prostate cancers.

CONCLUSIONS

Patients with esophageal adenocarcinoma and squamous cell carcinoma are at increased risk for the development of specific second primary cancers that share smoking as a common risk factor. Esophageal adenocarcinoma does not have a strong association with obesity-related cancers with respect to the relative risk for the development of subsequent primary cancers.

Mature adipocytes and perivascular adipose tissue stimulate vascular smooth muscle cell proliferation: effects of aging and obesity

Adipocytes and perivascular adipose tissue are emerging as regulators of vascular function. The effects of adipocytes and perivascular adipose tissue on human smooth muscle cell (SMC) proliferation were investigated. Conditioned medium was prepared from cultured premature and differentiated 3T3-L1 adipocytes and from periaortic adipose tissue from young (3 mo) and old (24 mo) Wistar-Kyoto (WKY) rats, lean and obese Zucker rats (3 mo), and WKY rats fed normal chow or a high-fat diet for 3 mo. Conditioned medium from differentiated (but not premature) adipocytes stimulated SMC proliferation, which was abolished by charcoal and proteinase K treatment but was resistant to heat, trypsin, or phospholipase B (to hydrolyze lysophosphatidic acid). Further experiments demonstrated that the growth factor(s) are hydrosoluble and present in the fraction of molecular mass >100 kDa. Moreover, conditioned medium from periaortic adipose tissue stimulated SMC proliferation, which was significantly enhanced in aged rats and in rats fed a high-fat diet but not in obese Zucker rats deficient in functional leptin receptors. In conclusion, mature adipocytes release hydrosoluble protein growth factor(s) with a molecular mass >100 kDa for SMCs. Perivascular adipose tissue stimulates SMC proliferation, which is enhanced in aged WKY and in high-fat, diet-induced obesity but not in leptin receptor-deficient obese Zucker rats. These adipocyte-derived growth factor(s) and the effect of perivascular adipose tissue may be involved in vascular disease associated with aging and obesity.

Breast cancer risk in the WHI study: The problem of obesity

In the climacteric, about 40% of the women have occult breast tumors the growth of which may be stimulated by hormones. Many genetic, reproductive and lifestyle factors may influence the incidence of breast cancer. Epidemiological data suggest that the increase in the relative risk (RR) of breast cancer induced by hormone replacement therapy (HRT) is comparable with that associated with early menarche, late menopause, late first birth, alcohol consumption, etc. One of the most important risk factors is obesity which exceeds the effect of HRT by far, and in overweight postmenopausal women the elevated risk of breast cancer is not further increased by HRT. As in the WHI study the majority of women was overweight or obese, this trial was unsuitable for the investigation of breast cancer risk. In the women treated with an estrogen/progestin combination, the RR of breast cancer rose only in those women who have been treated with hormones prior to the study, suggesting a selection bias. In the women not pretreated with hormones, it was not elevated. In the estrogen-only arm of the WHI study, there was no increase but a steady decrease in the RR of breast cancer during 6.8 years of estrogen therapy. This result was unexpected, as estrogens are known to facilitate the development and growth of breast tumors, and the effect is enhanced by the addition of progestins. Obese women are at high risk to develop a metabolic syndrome including insulin resistance and hyperinsulinemia. In postmenopausal women, elevated insulin levels are not only associated with an increased risk for cardiovascular disease, but also for breast cancer. This might explain the effects observed in both arms of the WHI study: HRT with relative low doses of estrogens may improve insulin resistance and, hence, reduce the elevated breast cancer risk in obese patients, whereas this beneficial estrogen effect may be antagonized by progestins. The principal options for the reduction of breast cancer risk in postmenopausal women are the prevention of overweight and obesity to avoid the development of hyperinsulinemia, the medical treatment of insulin resistance, the use of low doses of estrogens and the reduction of exposure to progestins. The latter might include long-cycles with the sequential use of appropriate progestins every 3 months for 14 days. There are large inter-individual variations in the proliferative response to estrogens of the endometrium. Control by vaginalsonography and progestin challenge tests may help to identify those women who may be candidates for low-dose estrogen-only therapy.

Acute and "chronic" phase reaction-a mother of disease

The world is increasingly threatened by a global epidemic of chronic diseases. Almost half of the global morbidity and almost two thirds of global mortality is due to these diseases-approximately 35 million die each year from chronic diseases. And they continue to increase. Increasing evidence suggest that these diseases are associated with lifestyle, stress, lack of physical exercise, over-consumption of calorie-condensed foods rich in saturated fat, sugar and starch, but also under-consumption of antioxidant-rich fruits and vegetables. As a result the function of the innate immune system is severe impaired. This review discusses the changes induced in response to mental and physical stress and their association with the subsequent development of metabolic syndrome, and its association with various chronic diseases. The endothelial cells and their function appears to be of great importance, and the function of their cellular membranes of special importance to the function of the underlying cells; their ability to obtain nutrients and antioxidants and to eliminate waste products. The abdominal adipocytes seen to play a key role, as they have the ability to in stressful situations release much of proinflammatory cytokines, PAI-1 and free fatty acids compared to elsewhere in the body. The load on the liver of these various substances in often of greater magnitude than the liver can handle. Some of the most common chronic diseases and their potential association with acute and "chronic" phase response, and with metabolic syndrome are discussed separately. The need for studies with lifestyle modifications is especially emphasized.

Sertoli-Leydig cell tumour in a postmenopausal woman showing all facets of the insulin resistance syndrome (IRS)

Sertoli-Leydig cell tumours are rare sex stromal tumours with an incidence of < 0.5% of all ovarian tumours. Most frequently this tumour occurs in young women with a history of amenorrhoea, hirsutism and lowered pitch. Here, we report on a woman with IRS, postmenopausal virilization and increased testosterone levels due to a Sertoli-Leydig cell tumour. This is the first case to suggest an association between IRS and Sertoli-Leydig cell tumours. Furthermore, we highlight the difficulties in detecting this ovarian tumour with sonography.

Le double-jeu de la protéine TIP47

A missing link in the understanding of the mechanisms of transport of the mannose 6-phosphate receptors has recently been discovered, following the identification of the protein TIP47. In association with Rab9-GTP, this protein is responsible for the return of the receptors from the late endosomes back to the trans-Golgi network. Curiously, the same protein called PP17b, was described as a placental protein twenty years ago, and more recently, as a blood marker for human uterine cervical cancer. The sequence of PP17b/TIP47 displays not only a strong homology with those of adipophilin and the perilipins, two proteins known to be involved in the intracellular traffic of lipid droplets but also PP17b/TIP47 is associated with the later. How this ubiquitous protein could participate in processes as different as the mannose 6-phosphate receptors traffic and the formation and/or traffic of lipid droplets? A tentative hypothesis is put forward.

Osteoporosis and breast cancer

Osteoporosis affects one in three women after the menopause and the incidence of osteoporotic fractures increases steadily throughout life. Breast cancer is the most common cancer in women, both before and after the menopause. In younger women, recovery from breast cancer has been achieved using aggressive chemotherapy and radiotherapy that can adversely affect bone tissue or induce premature menopause. In postmenopausal women, breast cancer and osteoporosis are common, and although both are dependent on estrogens this leads to conflicting implications for the diagnosis and treatment: estrogens reduce the risk of fractures but increase the risk of breast cancer. Estrogen supplementation is, therefore, contraindicated in patients with a history of breast cancer. Selective estrogen response modifiers (SERMs) hold great promise, as they decrease both the fracture risk via an estrogen-agonist effect on bone and the breast cancer risk via an estrogen-antagonist effect on the breast tissue. SERMs can be used after successful treatment for breast cancer. Bisphosphonates, which are potent bone resorption inhibitors, are widely used both in cancer patients and in the prevention and treatment of spinal and peripheral osteoporotic fractures. Contraindications are exceedingly rare, and the satisfactory safety profile of these agents can be expected to improve further with newly developed modes of administration. Whether the bisphosphonates currently used to treat osteoporosis (alendronate and risendronate) have beneficial effects on skeletal events related to cancer progression remains to be determined, however. In sum, selection of the optimal treatment for osteoporosis in a patient with breast cancer involves assessment of the risk/benefit ratio of each treatment option, based on patient age, other risk factors for osteoporosis, and the stage of breast cancer progression.

Abdominal adiposity in U.S. adults: prevalence and trends, 1960-2000

BACKGROUND

There is a large body of epidemiologic evidence linking abdominal obesity to cardiovascular diseases. Abdominal adiposity is an important component of insulin resistance syndrome.

OBJECTIVE

To investigate prevalence and trends in abdominal obesity in U.S. adult population. DESIGN, SETTING/PARTICIPANTS: Nationally representative cross-sectional surveys with an in-person interview and measurement of waist circumference; 23,654 adults aged 20-79 years were examined using data from U.S. National Surveys of 1960-1962 [the first National Health Examination Survey (NHES I)], 1988-1994 [the third National Health and Nutrition Examination Survey (NHANES III)] and 1999-2000 [National Health and Nutrition Examination Survey (NHANES 1999-2000)]. Abdominal obesity was defined as waist circumference > or = 102 cm (>40 in.) in men and > or = 88 cm (>35 in.) in women.

RESULTS

There was a gradient of increasing waist circumference over the three periods of 1960-1962, 1988-1994 and 1999-2000 in both men and women. In men, the mean waist circumferences were 89, 95 and 99 cm for 1960-1962, 1988-1994 and 1999-2000, respectively. The corresponding values in women were 77, 92 and 94 cm, respectively. A gradient of increasing prevalence of abdominal obesity from 1960 to 2000 was also observed in men and women. In men, the overall age-adjusted prevalences of abdominal obesity were 12.7%, 29% and 38.3% in 1960-1962, 1988-1994 and 1999-2000, respectively. In women, the analogous values were 19.4%, 38.8% and 59.9%, respectively. Similar trends of increasing waist circumference and abdominal obesity were observed in normal weight, underweight and obese subjects defined using body mass index (BMI). Trends of increasing abdominal obesity with increasing BMI over the three time periods were also observed.

CONCLUSIONS

The increase in the prevalence of abdominal obesity in the United States between 1960-1962 and 1999-2000 has ominous public health implications across entire population, particularly among normal weight subjects. There is an urgent need to describe a public health strategy for early identification of abdominal obesity. Primary prevention of obesity, including abdominal obesity, should be a major public health priority in the United States.

Tumour necrosis factor-alpha, interleukin-6, and fasting serum insulin correlate with clinical outcome in metastatic breast cancer patients treated with chemotherapy

INTRODUCTION

To assess the relationship of various growth factors and cytokines with the clinical outcome in metastatic breast cancer patients receiving chemotherapy.

METHODS

Consecutive, metastatic breast cancer patients with measurable disease and receiving palliative chemotherapy were prospectively evaluated for the predictors of progression free survival (PFS) and overall survival (OAS) in relation to serum insulin, insulin resistance, interleukin-6 (IL-6), and tumour necrosis factor-alpha (TNF-alpha).

RESULTS

Estrogen receptor (ER) status, serum IL-6 and serum TNF- were the independent determinants of PFS, with RR=0.28 (0.13-0.60), P=0.001, RR=2.48 (1.24-5.61), P=0.012, and RR=0.48 (0.23-1.01), P=0.053, respectively. The factors related with OAS in the multivariate analysis were histological grade (RR=7.88 (2.33-26.62), P=0.001), ER status (RR=0.18 (0.06-0.57), P=0.003), serum insulin (RR=0.87 (0.77-0.97), P=0.016), and serum IL-6 (RR=5.99 (1.89-18.97), P=0.002).

CONCLUSIONS

We show for the first time that fasting serum insulin and TNF-alpha levels are independent predictors for OAS and PFS, respectively, in metastatic breast cancer patients. In addition, we also confirm that IL-6 is a poor prognosticator in this group. These results suggest that insulin and TNF-alpha are important biomolecules that may be directly involved in vivo in the progression of metastatic breast cancer.