Premorbid body weight and its relations to primary tumour diameter in breast cancer patients; its dependence on estrogen and progesteron receptor status

Impact of Obesity on Breast Cancer Clinicopathological Characteristics in Underserved US Community Safety-Net Hospital: A Retrospective Single-Center Study

BACKGROUND

Breast cancer continues to pose a significant public health challenge, with its incidence and disproportionate impact on underserved populations in the United States. The relationship between obesity and clinicopathological characteristics at presentation remains a critical area of investigation. Safety-net hospitals caring for underserved communities provide a unique setting to explore these associations. This study seeks to explore a critical gap in knowledge on obesity and breast cancer characteristics in underserved populations in the United States.

MATERIALS AND METHODS

In this retrospective study, 927 breast cancer patients were included. Analysis was conducted to assess the association between body mass index (BMI), age of diagnosis, tumor clinicopathologic characteristics, and molecular types stratified by menopausal status at diagnosis. Analysis was performed using the Statistical Package for Social Sciences version 29.

RESULTS

A significant association was found between BMI and menopausal status (P < .05). Disease stage at presentation was significantly associated with BMI (P < .05). Further investigation into BMI categories and tumor characteristics revealed a significant correlation in postmenopausal women, with obesity linked to tumor size and lymph node status (P < .05). No significant associations were observed between HER-2 status, ER/PR status, and obesity in either premenopausal or postmenopausal groups.

CONCLUSION

This observational retrospective hypothesis-generating study revealed the association between obesity and disease stage and menopause status at diagnosis. In postmenopausal patients, obesity correlated with larger tumor size and advanced lymph node disease involvement. Additionally, ethnic variations were observed, with a higher prevalence of obesity among African American patients.

Obesity Modulates the Gut Microbiome in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is an aggressive, molecularly heterogeneous subtype of breast cancer. Obesity is associated with increased incidence and worse prognosis in TNBC through various potential mechanisms. Recent evidence suggests that the gut microbiome plays a central role in the progression of cancer, and that imbalances or dysbiosis in the population of commensal microbiota can lead to inflammation and contribute to tumor progression. Obesity is characterized by low-grade inflammation, and gut dysbiosis is associated with obesity, chronic inflammation, and failure of cancer immunotherapy. However, the debate on what constitutes a "healthy" gut microbiome is ongoing, and the connection among the gut microbiome, obesity, and TNBC has not yet been addressed. This study aims to characterize the role of obesity in modulating the gut microbiome in a syngeneic mouse model of TNBC. 16S rRNA sequencing and metagenomic analyses were performed to analyze and annotate genus and taxonomic profiles. Our results suggest that obesity decreases alpha diversity in the gut microbiome. Metagenomic analysis revealed that obesity was the only significant factor explaining the similarity of the bacterial communities according to their taxonomic profiles. In contrast to the analysis of taxonomic profiles, the analysis of variation of functional profiles suggested that obesity status, tumor presence, and the obesity-tumor interaction were significant in explaining the variation of profiles, with obesity having the strongest correlation. The presence of tumor modified the profiles to a greater extent in obese than in lean animals. Further research is warranted to understand the impact of the gut microbiome on TNBC progression and immunotherapy.

Breast Adipocyte Co-culture Increases the Expression of Pro-angiogenic Factors in Macrophages

Obese individuals with breast cancer have a poorer prognosis and higher risk of metastatic disease vs. non-obese patients. Adipose tissue in obese individuals is characterized by an enhanced macrophage infiltration, creating a microenvironment that favors tumor progression. Here, we demonstrate a role for adipocyte-macrophage interactions in the regulation of angiogenesis. Co-culture of THP-1 macrophages with human breast adipocytes led to increased expression of the pro-angiogenic growth factor, vascular endothelial growth factor A (VEGFA). Several adipocyte-derived proteins including leptin, insulin, IL-6, and TNF-α were each capable of increasing VEGFA expression in THP-1 macrophages, identifying these as possible mediators of the changes that were observed with co-culture. Furthermore, analysis of THP-1 culture media by antibody array revealed that THP-1 secrete several other pro-angiogenic signals in response to adipocyte co-culture, including interleukin 8 (IL-8), matrix metalloproteinase 9 (MMP9), pentraxin 3 (PTX3), and serpin E1 (plasminogen activator inhibitor 1, PAI1) after co-culture with human adipocytes. We used an in vitro endothelial tube formation assay with human vascular endothelial cells to evaluate the effects of THP-1 culture media on angiogenesis. Here, culture media from THP-1 cells previously exposed to human adipocytes stimulated endothelial tube formation more significantly than THP-1 cells cultured alone. In summary, we find that adipocyte co-culture stimulates the expression of pro-angiogenic mediators in macrophages and has pro-angiogenic effects in vitro, thus representing a possible mechanism for the enhanced risk of breast cancer progression in obese individuals.

Obesity and breast cancer screening: Cross-sectional survey results from the behavioral risk factor surveillance system

BACKGROUND

Postmenopausal obese women demonstrate an elevated breast cancer risk and experience increased breast cancer morbidity and mortality compared with women with a normal body mass index (BMI). However, to the authors' knowledge, prior studies have yielded inconclusive results regarding the effects of obesity on mammography screening adherence. Using national cross-sectional survey data, the objective of the current study was to assess the current association between increasing BMI and use of mammography screening.

METHODS

Cross-sectional survey data from the 2016 Behavioral Risk Factor Surveillance System, a state-based national telephone survey of noninstitutionalized adults in the United States, was used to identify the association between mammography screening use and increasing incremental BMI categories, including normal (18.5-24.9 kg/m2 ), overweight (25-29.9 kg/m2 ), obese class I (30-34.9 kg/m2 ), obese class II (35-39.9 kg/m2 ), and obese class III (>40 kg/m2 ), with adjustments for potential confounders. A multivariable logistic regression model was used to evaluate the effect of each BMI category on self-reported mammography use, using unadjusted and adjusted odds ratios. Effect modification by race/ethnicity was determined by testing interaction terms using Wald tests.

RESULTS

Of 116,343 survey respondents, 33.5% (38,984 respondents) had a normal BMI, 32.6% (37,969 respondents) were overweight, 19.3% (22,416 respondents) were classified as obese class I, 8.4% (9791 respondents) were classified as obese class II, and 6.2% (7183 respondents) were classified as obese class III. There was no statistically significant difference (P < .05) observed with regard to mammography use between women with a normal BMI and obese women from each obese class (classes I-III) when compared individually. There also was no evidence of effect modification by race (P = .53).

CONCLUSIONS

In contrast to prior reports, the results of the current study demonstrated no association between obesity and adherence to screening mammography. These findings may relate to the increasing social acceptance of obesity among women from all racial/ethnic groups and the removal of weight-related facility-level barriers over time.

Weight Gain during Neoadjuvant Chemotherapy is Associated with Worse Outcome among the Patients with Operable Breast Cancer

Purpose

This study was aimed at identifying the influence of initial weight and weight change during neoadjuvant chemotherapy (NAC) on pathologic complete response (pCR) and long-term survival in Chinese patients with operable breast cancer.

Methods

We conducted a retrospective study using data from 409 female patients who received NAC for stage II or III breast cancer and had complete record of body mass index (BMI) before and after NAC. BMI of < 25 kg/m² was categorized as normal weight/underweight (NW/UW); 25.0–29.9 kg/m² was categorized as overweight (OW); ≥30 kg/m² was categorized as obese (OB). BMI change was defined as the difference in BMI between day 1 of the first cycle of NAC and the day before surgery. A BMI gain or loss of > 2 kg/m² following NAC was considered to be significant, else was considered stable. The study end points included pCR rates, disease-free survival (DFS), and overall survival (OS).

Results

The median follow-up time was 43.2 (8.9–93.6) months. The average BMI was 23.40 ± 3.04 kg/m² before NAC and 23.66 ± 3.02 kg/m² after NAC (t = −3.604, p < 0.001). The pCR rate was 25.3% in the NW/UW group and 24.1% in the OW/OB group (p = 0.811), and was similar between the BMI-gain (23.3%) and the BMI-stable/loss (25.1%) groups (p = 0.787). Initial BMI was an independent prognostic factor for DFS (hazard ratio, 1.69; 95% confidence interval [CI], 1.13–2.53; p = 0.011) but not for OS, while BMI-gain was an independent prognostic factor for both DFS (hazard ratio, 2.09; 95% CI, 1.28–3.42; p = 0.003) and OS (hazard ratio, 1.97; 95% CI, 1.04–3.74; p = 0.039).

Conclusion

BMI increased after NAC in Chinese breast cancer patients. Initial BMI and BMI change during NAC were not associated with pCR but were reversely associated with survival.

Obesity promotes the expansion of metastasis-initiating cells in breast cancer

Background

Obesity is a strong predictor of poor prognosis in breast cancer, especially in postmenopausal women. In particular, tumors in obese patients tend to seed more distant metastases, although the biology behind this observation remains poorly understood.

Methods

To elucidate the effects of the obese microenvironment on metastatic spread, we ovariectomized C57BL/6 J female mice and fed them either a regular diet (RD) or a high-fat diet (HFD) to generate a postmenopausal diet-induced obesity model. We then studied tumor progression to metastasis of Py230 and EO771 grafts. We analyzed and phenotyped the RD and HFD tumors and the surrounding adipose tissue by flow cytometry, qPCR, immunohistochemistry (IHC) and western blot. The influence of the microenvironment on tumor cells was assessed by performing cross-transplantation of RD and HFD tumor cells into other RD and HFD mice. The results were analyzed using the unpaired Student t test when comparing two variables, otherwise we used one-way or two-way analysis of variance. The relationship between two variables was calculated using correlation coefficients.

Results

Our results show that tumors in obese mice grow faster, are also less vascularized, more hypoxic, of higher grade and enriched in CD11b⁺Ly6G⁺ neutrophils. Collectively, this favors induction of the epithelial-to-mesenchymal transition and progression to claudin-low breast cancer, a subtype of triple-negative breast cancer that is enriched in cancer stem cells. Interestingly, transplanting HFD-derived tumor cells in RD mice transfers enhanced tumor growth and lung metastasis formation.

Conclusions

These data indicate that a pro-metastatic effect of obesity is acquired by the tumor cells in the primary tumor independently of the microenvironment of the secondary site.

Graphical abstract

Effects of postmenopausal obesity on primary breast cancer tumoursᅟ

Electronic supplementary material

The online version of this article (10.1186/s13058-018-1029-4) contains supplementary material, which is available to authorized users.

Correlation of BMI with breast cancer subtype and tumour size

Background

Breast cancer is a heterogeneous disease which is divided broadly into luminal, HER2 and basal type based on molecular profiling. Increased body mass index (BMI) has been associated with the risk of developing breast cancer but the association based on molecular subtype remains conflicting.

Methods

This was an observational study carried out over a period of 2 years. Nonmetastatic breast cancer patients were evaluated for the tumour subtype based on surrogate markers (ER, PR and HER2). The BMI of these patients was correlated with the tumour subtype and size.

Results

We studied 476 patients with breast cancer with the median age of 46 years (range, 25–86) and 58% were premenopausal. The mean BMI of the cohort was 24.1, which was significantly higher in postmenopausal women (24.9 versus 23.6, p < 0.05). Overall, only 10% of patients were obese. The mean BMI in the luminal, HER2 and TNBC subtypes was 24.7, 22.4 and 23.9, respectively (p < 0.01). Also, the mean tumour size in luminal, HER2 and TNBC subtype was 4.02, 3.80 and 4.27 cm, respectively (p = 0.158).

Conclusion

The average BMI was higher in patients with luminal subtype followed by TNBC and lowest for HER2 at the time of diagnosis. The mean tumour size was numerically higher for TNBC and lowest for HER2 subtype although the difference was not statistically significant. Larger studies may provide clarity of association between the BMI and tumour subtype.

Long-term prognostic implications of risk factors associated with tumor size: a case study of women regularly attending screening

Background

Breast cancer prognosis is strongly associated with tumor size at diagnosis. We aimed to identify factors associated with diagnosis of large (> 2 cm) compared to small tumors, and to examine implications for long-term prognosis.

Methods

We examined 2012 women with invasive breast cancer, of whom 1466 had screen-detected and 546 interval cancers that were incident between 2001 and 2008 in a population-based screening cohort, and followed them to 31 December 2015. Body mass index (BMI) was ascertained after diagnosis at the time of study enrollment during 2009. PD was measured based on the contralateral mammogram within 3 years before diagnosis. We used multiple logistic regression modeling to examine the association between tumor size and body mass index (BMI), mammographic percent density (PD), or hormonal and genetic risk factors. Associations between the identified risk factors and, in turn, the outcomes of local recurrence, distant metastases, and death (153 events in total) in women with breast cancer were examined using Cox regression. Analyses were carried out according to mode of detection.

Results

BMI and PD were the only factors associated with tumor size at diagnosis. For BMI (≥25 vs. < 25 kg/m²), the multiple adjusted odds ratios (OR) were 1.37 (95% CI 1.02–1.83) and 2.12 (95% CI 1.41–3.18), for screen-detected and interval cancers, respectively. For PD (≥20 vs. < 20%), the corresponding ORs were 1.72 (95% CI 1.29–2.30) and 0.60 (95% CI 0.40–0.90). Among women with interval cancers, those with high BMI had worse prognosis than women with low BMI (hazard ratio 1.70; 95% CI 1.04–2.77), but PD was not associated with the hazard rate. Among screen-detected cancers, neither BMI nor PD was associated with the hazard rate.

Conclusions

In conclusion, high BMI was associated with the risk of having a tumor larger than 2 cm at diagnosis. Among women with interval cancer, high BMI was associated with worse prognosis. We believe that women with high BMI should be especially encouraged to attend screening.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-0962-6) contains supplementary material, which is available to authorized users.

A role for FGF2 in visceral adiposity-associated mammary epithelial transformation

Obesity is a leading risk factor for post-menopausal breast cancer, and this is concerning as 40% of cancer diagnoses in 2014 were associated with overweight/obesity. Despite this epidemiological link, the underlying mechanism responsible is unknown. We recently published that visceral adipose tissue (VAT) releases FGF2 and stimulates the transformation of skin epithelial cells. Furthermore, obesity is differentially associated with many epithelial cancers, and this mechanistic link could be translational. As FGF2 and FGFR1 are implicated in breast cancer progression, we hypothesize that VAT-derived FGF2 plays a translational role in promoting adiposity-associated mammary epithelial cell transformation. In this brief report, data suggest that FGF2/FGFR1 signaling is a potential mechanistic link in VAT-stimulated transformation of breast epithelial cells.

Deciphering metabolic rewiring in breast cancer subtypes

Metabolic reprogramming, an emerging hallmark of cancer, is observed in breast cancer. Breast cancer cells rewire their cellular metabolism to meet the demands of survival, proliferation, and invasion. However, breast cancer is a heterogeneous disease, and metabolic rewiring is not uniform. Each subtype of breast cancer displays distinct metabolic alterations. Here, we focus on unique metabolic reprogramming associated with subtypes of breast cancer, as well as common features. Therapeutic opportunities based on subtype-specific metabolic alterations are also discussed. Through this discussion, we aim to provide insight into subtype-specific metabolic rewiring and vulnerabilities that have the potential to better guide therapy and improve outcomes for patients.

Obesity and Prognostic Variables in Colombian Breast Cancer Patients: A Cross-Sectional Study

Introduction

Obesity is an established risk factor for cancer and cancer-related deaths, including that of the breast. While the prevalence of female obesity has accelerated over the past decade in many developing countries, such as Colombia, the prevalence of overweight and obesity specifically in breast cancer populations has not been fully described.

Methods

A cross-sectional study including 849 women diagnosed with breast cancer between 2009 and 2014. Based on body mass index, prevalence of overweight (BMI ≥ 25 < 30) and obesity (BMI ≥ 30) and associations of BMI with clinical and tumor histopathological features were analyzed.

Results

Colombian breast cancer patients had a prevalence of overweight of 34.28% and obesity of 28.15%. Mean BMI was comparable between premenopausal and postmenopausal women (27.2 versus 27.7, resp.). Among premenopausal women, higher BMI was significantly positively associated with hormone receptor negative tumors, as well as with greater lymphovascular invasion.

Conclusions

Colombian breast cancer patients exhibit a significant prevalence of overweight and obesity. Associations of high BMI and poor prognosis variables in the premenopausal population suggest risk of aggressive disease in this population. Future studies to further validate our observations are warranted in order to implement multidisciplinary clinical guidelines.

Elevated Serum Levels of Retinol-Binding Protein 4 Are Associated with Breast Cancer Risk: A Case-Control Study

Background

Retinol binding protein 4 (RBP4) is a recently identified adipokine that is elevated in patients with obesity or type 2 diabetes. A growing body of research has shown that RBP4 is associated with several types of cancer. However, no studies have investigated the relationship between serum RBP4 levels and breast cancer risk. We performed a case-control study to evaluate the association between serum RBP4 levels and the risk of breast cancer.

Methods

From August 2012 to December 2013, four-hundred subjects including 200 patients diagnosed with primary breast cancer and 200 matched healthy women were consecutively enrolled from Affiliated Hospital of Qingdao University Medical College. Blood samples were collected from healthy controls and breast cancer patients before commencement of treatment. Enzyme-linked immunosorbent assay was used to evaluate the serum RBP4 levels in separated serum samples. Meanwhile, the characteristics of breast cancer cases and controls were collected from medical records and pathological data.

Results

The serum levels of RBP4 were significantly higher in patients with breast cancer than that in the healthy control group (33.77±9.92 vs. 28.77±6.47μg/ml, P < 0.05). Compared to the subjects in the lowest quartile of serum RBP4 level, the adjusted ORs (95% CIs) is 2.16(1.01–4.61) and 2.07 (1.07–4.00) for women in the second and highest RBP4 tertile, respectively. For breast cancer patients, patients with PR or ER negative displayed significantly higher serum RBP4 levels than those with PR or ER positive.

Conclusion

Our results for the first time suggested serum RBP4 levels could be associated with the risk of breast cancer. However, further prospective studies are essential to confirm these observed results.

The association between body mass index and immunohistochemical subtypes in breast cancer

BACKGROUND

Body mass index (BMI) is defined as a poor prognostic factor in patients with breast cancer (BC). However, there are controversial results regarding the various effects of BMI on BC, hence the exact pathophysiology of the relation between obesity and BC is still under debate, and remains unclear. This paper aims to investigate the association between BMI at presentation and BC subtypes defined according to the immunohistochemical classification in both premenopausal and postmenopausal patients with BC.

PATIENTS AND METHODS

This study is a retrospective and explorative analysis of the 3767 female BC patients from a single center. All patients' BMI at the time of initial diagnosis and tumor demographics were recorded. BMI was stratified into 3 groups as normal-weighted (BMI <25 kg/m²), over-weighted (BMI = 25-29.9 kg/m²), and obese (BMI ≥30 kg/m²). Immunohistochemical classification of the tumors was categorized into 4 groups as follows; luminal-like, HER2/luminal-like, HER2-like, and triple-negative according to the ER/PR and HER2 status. Distribution of Immunohistochemical subtypes, tumor characteristics, and overall survival (OS) analysis were evaluated according to the BMI groups in both premenopausal and postmenopausal patients.

RESULTS

Median BMI of premenopausal and postmenopausal patients was 25.5 (kg/m²) and 28.8 (kg/m²), respectively (P < 0.001). In parallel with the increasing age, patients were more obese at diagnosis in both premenopausal (P < 0.001) and postmenopausal period (P < 0.001). Triple-negative subtype was significantly more frequent in premenopausal patients with BMI ≥30 kg/m² compared to BMI <30 kg/m² (P = 0.007). Additionally, premenopausal patients with BMI ≥30 kg/m² had less common luminal-like subtype (P = 0.033) and more frequently presented with higher tumor stage (P = 0.012) and tumor grade (P = 0.004) compared to patients with BMI <25 kg/m². On the other hand, premenopausal patients with BMI <25 kg/m² had significantly more ER-positive tumors (P < 0.001) and lower stages of disease (P = 0.01) compared to their counterparts with BMI ≥25 kg/m². Premenopausal obese patients with triple-negative (P = 0.001) and luminal-like subtype (P = 0.002) had significantly shorter OS duration compared to overweight counterparts. HER2/luminal-like subtype was found to be significantly greater in postmenopausal overweight patients (P = 0.005). However, BMI had no any other significant effect on survival and immunohistochemical subtypes in postmenopausal patients. Multivariate analysis revealed that triple-negative subtype, grade III tumor, BMI ≥30 kg/m², T3-4 (P < 0.001), nodal involvement, metastatic disease, and lymphovascular involvement were significantly associated with poorer OS.

CONCLUSION

Our data indicated that BMI was an independent factor in patients with BC, with an association indicating a decreased incidence for luminal-like subtype and increased incidence for triple-negative subtype among premenopausal patients. However, this significance was not found in postmenopausal patients. Accordingly, a plausible etiological heterogeneity in BC might play a role among immunohistochemical subtypes in every life stage of women.

Obesity and Breast Cancer: A Complex Relationship

As prevalence of obesity continues to rise in the United States, we are beginning to elucidate the complex role of obesity-associated chronic inflammation, endocrine dysfunction, and hormone production as a driver for increased breast cancer risk. Epidemiological data suggest that obesity (BMI > 30) is associated with increased breast cancer incidence, worse prognosis, and higher mortality rates. Mechanistically, obesity and excess fat mass represent a state of chronic inflammation, insulin resistance, adipokine imbalance, and increased estrogen signaling. This pro-tumorigenic environment stimulates cancer development through abnormal growth, proliferation, and survival of mammary tissue. Importantly, obesity is a modifiable risk factor; alterations in cell proliferation, apoptosis, circulating estrogen, and insulin sensitivity are observed in response to weight loss attainable through behavior modification including dietary and exercise changes.

The obesity-inflammation-eicosanoid axis in breast cancer

Inflammation of the adipose tissues occurs in association with obesity. This inflammatory process leads to the induction of cyclooxygenase-2 (COX-2) expression and a consequent elevation in prostaglandin (PG) production, which, together with proinflammatory cytokines, induce aromatase expression and estrogen synthesis. Infiltrating macrophages support the growth of breast epithelial cells and vascular endothelial cells by producing a milieu of cytokines and growth factors. This scenario creates a microenvironment favorable to breast cancer growth and invasion. The eicosanoids promote further development and growth of breast cancers indirectly by the induction of aromatase, particularly in estrogen positive breast cancers, or by direct stimulatory effect of PGE2 and lipoxygenase (LOX) products on the more aggressive, estrogen-independent tumors. Beyond this, the local production of estrogens and proinflammatory cytokines which occurs in association with breast adipose tissue inflammation, and consequent activation of the estrogen receptor and nuclear factor-κB, provides a mechanism by which breast cancers develop resistance to selective estrogen receptor modulation and aromatase inhibitor therapy. The obesity-inflammation-eicosanoid axis in breast cancer does offer a therapeutic target for the prevention of relapse in breast cancer by improving the efficacy of antiaromatase therapy using COX/LOX inhibitors; however, careful consideration of menopausal status and obesity in patients is warranted.

Effects of obesity on presentation of breast cancer, lymph node metastasis and patient survival: a retrospective review

BACKGROUND

As data on the relation between obesity and lymph node ratio are missing in the literature, we here aimed to assess the impact of obesity on this parameter and other clinicopathological features of breast cancer cases and patient survival.

MATERIALS AND METHODS

Medical data of 646 patients, all referred to two centers in Tehran, Iran, were reviewed. Factors that showed significant association on univariate analysis were entered in a regression model. Kaplan-Meier and Cox-regression were employed for survival analysis.

RESULTS

Obesity was correlated with the expression of estrogen and progesterone receptor (p=0.004 and p=0.039, respectively), metastasis to axillary lymph nodes (p=0.017), higher lymph node rate (p<0.001) and larger tumor size (p<0.001). The effect of obesity was stronger in premenopausal women. There was no association between obesity and expression of human epidermal growth factor receptor. Three factors showed independent association with BMI on multivariate analysis; tumor size, estrogen receptor and lymph node ratio. Obesity was predictive of shorter disease-free survival with a hazard ratio of 3.324 (95%CI: 1.225-9.017) after controlling for the above-mentioned variables.

CONCLUSIONS

The findings of this study support the idea that obese women experience more advanced disease with higher axillary lymph node ratio, and therefore higher stage at the time of diagnosis. Furthermore, obesity was associated with poorer survival independent of lymph node rate.

Female Body Mass Index and its Relationship With Triple Negative Breast Cancer and Ethnicity

BACKGROUND

Breast cancer in women is a relatively common malignancy in the western hemisphere and is perhaps one of the leading causes of mortality among females. We conducted a retrospect cohort study to investigate the association of body mass index (BMI) with triple negative breast cancer and ethnicity.

METHODS

Tumor Registry Database at the University of Florida, College of Medicine in Jacksonville was utilized for our cohort study. A total of 84 women with triple negative breast cancer, between 2004 and 2008 met our criteria and were selected for this study. For comparison, another 83 women with at least one hormone receptors positive breast cancer were randomly selected in the same time period. Chi-square testing was used to evaluate categorical variables, while the t-test analysis was used to analyze for the continuous variables.

RESULTS

Our data demonstrated that 27.4% of the triple negative group had BMI < 25 compared to the 14.5% of non-triple negative breast cancer, 73.6% of the triple negative group had BMI ≥ 25 compared to 86.5% in the non-triple negative group with a P-value of 0.245. In terms of ethnicity, triple negative breast cancer was found in 56% of African-American and 44% of Caucasian females. Non-triple negative breast cancer was found in 48.2% of African-Americans and 51.8% of Caucasians females with a P-value of 0.354.

CONCLUSIONS

We were not able to show any statistically significant association of body mass index triple with triple negative breast cancer or ethnicity. While our findings are not in agreement with the research published earlier, we do submit that our retrospective cohort study has shortcomings, including the small sample size pooled from a single center, which greatly limits our ability to deduce any definitive conclusions. In light of these shortcomings, we recommend a future multicenter study with a larger sample size.

Body mass index (BMI) and breast cancer: impact on tumor histopathologic features, cancer subtypes and recurrence rate in pre and postmenopausal women

The study aims to analyze the association between body mass index (BMI) at time of diagnosis, breast cancer histopathologic features (tumor size, nuclear grade, estrogen and progesterone receptor (ER and PgR) and HER-2/neu expression, histological subtypes, Ki-67 index, lymphatic/vascular invasion, axillary nodes involvement) and incidence of different subtypes defined using hormone receptors and HER2/neu expression, according to menopausal status; to evaluate the impact of BMI on disease free survival (DFS) at multivariate analysis. A total of 2148 patients (592 premenopausal, 1556 postmenopausal) were classified into subgroups according to BMI distribution. High BMI was significantly associated with larger size tumor both in pre (p = 0.01) and postmenopausal women (p = 0.00). Obese premenopausal women showed worse histopathologic features (more metastatic axillary lymphnodes, p = 0.017 and presence of vascular invasion, p = 0.006) compared to under/normal weight group. Postmenopausal patients with BMI > 25 developed more frequently ER/PgR positive cancers (87% versus 75%, p 0.017), while no association was found in premenopausal women. We could not found any statistically significant correlation between breast cancer subtypes (luminal A, B, HER-2 and basal-like) and BMI both in pre and postmenopause. Higher BMI was significantly associated with a shorter DR-FS in postmenopausal women but the independent prognostic role of obesity was not confirmed in our analysis.

Differences between Hispanic and non-Hispanic white women with breast cancer for clinical characteristics and their correlates

PURPOSE

Body size and ethnicity may influence breast cancer tumor characteristics at diagnosis. We compared Hispanic and non-Hispanic white (NHW) cases for stage of disease, estrogen receptor (ER) status, tumor size, and lymph node status, and the associations of these with body size in the 4-Corners Breast Cancer Study.

METHODS

One thousand five hundred twenty-seven NHW and 798 Hispanic primary incident breast cancer cases diagnosed between October 1999 and May 2004 were included. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by multiple logistic regression.

RESULTS

Hispanic women were more likely to have larger (>1 cm) ER- tumors and more than four positive lymph nodes (P < .003). Lymph node status was not associated with body size. However, among NHW women, obesity (body mass index >30) and increased waist circumference (>38.5 inches) were significantly positively associated with ER- tumor status (OR, 1.87; 95% CI, 1.24-2.81 and OR, 2.59; 95% CI, 1.58-4.22, respectively). In contrast, among Hispanic women, obesity and waist circumference had inverse associations with ER- tumor status (OR, 0.49; 95% CI, 0.29-0.84 and OR, 0.56; 95% CI, 0.30-1.05, respectively).

CONCLUSIONS

Hispanic ethnicity may modify the association of body size and composition with ER- breast cancer. This finding could have relevance to clinical treatment and prognosis.

Obesity or overweight is associated with worse pathological response to neoadjuvant chemotherapy among Chinese women with breast cancer

Background

To evaluate the relationship between body mass index (BMI) and response to neoadjuvant chemotherapy (NCT) for breast cancer among Chinese women.

Patients and Methods

A total of 307 eligible patients were assigned to receive four cycles of paclitaxel and carboplatin before standard surgery for breast cancer from 2007 to 2011 at Shanghai Cancer Hospital. The patients were categorized as obese, overweight, normal weight, or underweight based on BMI according to World Health Organization (WHO) criteria. Pathological complete response (pCR) was defined as no invasive cancer in the breast or axillary tissue. A logistic regression and the Chi-squared test were used for detecting the predictors of pCR and determining the relationship between BMI category and pCR rate in the subgroup analysis with respect to other variables.

Results

Categorical BMI, estrogen receptor (ER), and progesterone receptor (PR) status were independent predictors of pCR according to the multivariate analysis. Patients with BMI≥25 were less likely to achieve a pCR to NCT compared with patients with BMI<25 (Odds ratio: 0.454, p = 0.033, multivariate analysis). In the subgroup analysis, the predictive value of BMI for pCR to NCT was significantly shown in post-menopausal patients (p = 0.004) and hormonal receptor status-negative patients (p = 0.038). The incidence of treatment-induced toxicity was similar among the different BMI categories.

Conclusion

Higher BMI was associated with worse pCR to NCT. Further approaches to investigating the mechanism of this influence of BMI on treatment response and a more appropriate schedule for calculating NCT dose for high-BMI-patients should be considered.

Importance of metabolic changes induced by chemotherapy on prognosis of early-stage breast cancer patients: a review of potential mechanisms

Weight variation has been reported as a side effect of chemotherapy treatment in early breast cancer patients and has been identified as a factor of poor prognosis. Causes of weight variation during chemotherapy and mechanisms involved in the poor prognosis have been little studied. Here is reviewed the current knowledge about the main causes and mechanisms involved in body weight change. Special emphasis is placed on factors associated with weight variation which could potentially be involved in the risk of relapse in breast cancer survivors. In recent decades, some studies have investigated the causes of weight variation by studying energy balance of breast cancer patients during chemotherapy. Weight gain or loss may be the consequence of energy imbalance through different factors linked with chemotherapy, such as poor treatment tolerance, decreased muscle mass and function, or hormonal alterations. This results in body composition modifications in favour of fat gain and/or lean body mass loss. Increased adipose tissue, especially in the abdominal region, could induce metabolic disturbances such as insulin resistance, through various pathways involving adipokines. These molecules have growth properties and could therefore play a role in cancer relapse. Understanding such mechanisms is key to developing preventive strategies for improving the prognosis of early-stage breast cancer patients.

The Possible Impact of Obesity on Androgen, Progesterone and Estrogen Receptors (ERα and ERβ) Gene Expression in Breast Cancer Patients

BACKGROUND

Obesity has been associated with increased mortality from hormone dependant cancers such as breast cancer which is the most prevalent cancer in women. The link between obesity and breast cancer can be attributed to excess estrogen produced through aromatization in adipose tissue. The role of steroid hormone receptors in breast cancer development is well studied but how obesity can affect the expression pattern of steroid hormones in patients with different grades of breast cancer was the aim of this study.

METHODS

In this case-control study, 70 women with breast cancer participated with different grades of obesity (36 none obese, BMI < 25 kg/m(2) and 34 obese, BMI ≥ 25 kg/m(2)). The mean age of participants was 44.53 ± 1.79 yr (21-70 yr). The serum level of estrogen, progesterone and androgen determined by ELISA. Following quantitative expression of steroid hormone receptors mRNA in tumor tissues evaluated by Real-time PCR. Patients with previous history of radiotherapy or chemotherapy were excluded. SPSS 16 was used for data analysis and P < 0.05 considered statistically significant.

RESULTS

The difference in ERα, ERβ and PR mRNA level between normal and obese patients was significant (P < 0.001). In addition, the expression of AR mRNA was found to be higher than other steroid receptors. There was no significant relation between ERβ gene expression in two groups (P = 0.68). We observed a significant relationship between ERα and AR mRNA with tumor stage and tumor grade, respectively (P = 0.023, P = 0.015).

CONCLUSION

According to the obtained results, it is speculated that obesity could paly a significant role in estrogen receptors gene expression and also could affect progression and proliferation of breast cancer cells.

Cancer-associated adipocytes exhibit an activated phenotype and contribute to breast cancer invasion

Early local tumor invasion in breast cancer results in a likely encounter between cancer cells and mature adipocytes, but the role of these fat cells in tumor progression remains unclear. We show that murine and human tumor cells cocultivated with mature adipocytes exhibit increased invasive capacities in vitro and in vivo, using an original two-dimensional coculture system. Likewise, adipocytes cultivated with cancer cells also exhibit an altered phenotype in terms of delipidation and decreased adipocyte markers associated with the occurrence of an activated state characterized by overexpression of proteases, including matrix metalloproteinase-11, and proinflammatory cytokines [interleukin (IL)-6, IL-1β]. In the case of IL-6, we show that it plays a key role in the acquired proinvasive effect by tumor cells. Equally important, we confirm the presence of these modified adipocytes in human breast tumors by immunohistochemistry and quantitative PCR. Interestingly, the tumors of larger size and/or with lymph nodes involvement exhibit the higher levels of IL-6 in tumor surrounding adipocytes. Collectively, all our data provide in vitro and in vivo evidence that (i) invasive cancer cells dramatically impact surrounding adipocytes; (ii) peritumoral adipocytes exhibit a modified phenotype and specific biological features sufficient to be named cancer-associated adipocytes (CAA); and (iii) CAAs modify the cancer cell characteristics/phenotype leading to a more aggressive behavior. Our results strongly support the innovative concept that adipocytes participate in a highly complex vicious cycle orchestrated by cancer cells to promote tumor progression that might be amplified in obese patients.

Difference in the expression of hormone receptors and fibrotic markers in the human peritoneum--implications for therapeutic targets to prevent encapsulating peritoneal sclerosis

OBJECTIVE

Encapsulating peritoneal sclerosis (EPS) is a rare but life-threatening complication of peritoneal dialysis (PD). The optimal management of patients with EPS is uncertain. In the present study, we investigated differences in the expression of nuclear receptors [progesterone (PR), androgen (AR), vitamin D (VDR), and glucocorticoid (GCR)] in the human peritoneum. We also investigated estrogen receptor (ER), matrix metalloproteinase 9 (MMP9), and transforming growth factor β1 (TGFβ1) in the context of their potential role in tamoxifen therapy.

METHODS

We analyzed clinical and histologic characteristics of 72 peritoneal biopsy specimens (22 from EPS patients, 11 from PD patients, 15 from uremic patients, and 24 from control subjects undergoing hernia repair). For immunophenotyping, we used antibodies against VDR, GCR, ER, PR, AR, MMP9, and TGFβ1.

RESULTS

In human peritoneum, VDR and GCR are highly expressed (98.6% and 87.3% respectively). Except in the case of VDR (p = 0.0012), we observed no significant difference in receptor expression between the groups. Expression of ER and PR was sparse (11.4% and 31% respectively), with higher expression in women, and AR was absent. Minimal MMP9 expression and moderate TGFβ1 expression were observed in all groups. The differences between the groups were nonsignificant.

CONCLUSIONS

Nuclear receptors are present in human peritoneum. Except in the case of VDR, the pattern for any one group is nonspecific. Glucocorticoids, vitamin D, and angiotensin converting-enzyme inhibitors or angiotensin II receptor blockers (via the vitamin D/angiotensin II pathway) might be suitable interventions for preservation of the integrity of the peritoneal membrane. The mechanism of action of tamoxifen is still not elucidated, ER expression in the peritoneum is sparse, and data about the studied pathways (MMP9, TGFβ) are inconsistent.

Obesity and breast cancer: status of leptin and adiponectin in pathological processes

It is well recognized that obesity increases the risk of various cancers, including breast malignancies in postmenopausal women. Furthermore, obesity may adversely affect tumor progression, metastasis, and overall prognosis in both pre- and postmenopausal women with breast cancer. However, the precise mechanism(s) through which obesity acts is/are still elusive and this relationship has been the subject of much investigation and speculation. Recently, adipose tissue and its associated cytokine-like proteins, adipokines, particularly leptin and adiponectin, have been investigated as mediators for the association of obesity with breast cancer. Higher circulating levels of leptin found in obese subjects could be a growth-enhancing factor as supported by in vitro and preclinical studies, whereas low adiponectin levels in obese women may be permissive for leptin's growth-promoting effects. These speculations are supported by in vitro studies which indicate that leptin promotes human breast cancer cell proliferation while adiponectin exhibits anti-proliferative actions. Further, estrogen and its receptors have a definite impact on the response of human breast cancer cell lines to leptin and adiponectin. More in-depth studies are needed to provide additional and precise links between the in vivo development of breast cancer and the balance of adiponectin and leptin.

Obesity augmented breast cancer risk: a potential risk factor for Indian women

BACKGROUND

Obesity is caused by disturbances of energy balance, which is homeostasized by the physiological processes. The study aims to determine the possible impact of rising prevalence of obesity and its effect in the development of breast carcinoma (BC) in Indian population.

METHODS

This study is carried out on patients (N = 358) who were diagnosed with BC and breast diseases (BD) by calculating their BMI admitted during the period of 2005 to 2009. NIH criteria were used to categorize the patients. Pathological factors of BC patient were then compared among groups.

RESULT

These results were indicative of significant positive association between BC risks with peri/post menopausal status, residence, diet nature, and tobacco uses. Metastases were identified more commonly with increasing weight. It was found to be independently associated with obesity I (OR = 3.103, 95% CI = 1.633-5.895) and obesity II (OR = 6.803, 95% CI = 2.415-19.162). Disease stage and cancer related mortality were significantly associated with increased BMI.

CONCLUSION

The higher prevalence of severe obesity among Indian population was associated with BC. The only alteration apart from early diagnosis is opting for a more natural lifestyle that will affect energy equilibrium and prove to be a viable option for prevention in carcinoma of breast for better survival.

Obesity, hyperinsulinemia and breast cancer: novel targets and a novel role for metformin

The relationship between obesity, metabolic syndrome, diabetes and cancer has been recognized for many years. Multiple studies conducted in the last 20 years have identified molecular mechanisms responsible for this phenomenon. Elucidation of the important role of insulin, IGF receptor, mTOR and AMP-activated protein kinase in breast cancer biology has led to the development and subsequent clinical evaluation of novel targeted therapies, including IGF-1 receptor-specific antibodies or tyrosine kinase inhibitors and inhibitors of mTOR. There is also a growing interest in the use of metformin, which has been shown to possess antitumor activity resulting from activation of AMP-activated protein kinase and subsequent inhibiton of mTOR, as well as from decreased circulating insulin levels. Metformin has been shown to inhibit proliferation, invasion and angiogenesis of neoplastic cells and to overcome resistance of breast cancer to chemotherapy, hormonal therapy and HER2 inhibition. Recently, metformin has been demonstrated to inhibit breast cancer stem cell growth and to synergize with chemotherapy in suppression of tumor growth and prolongation of survival of breast tumor-bearing animals. Several currently ongoing Phase II and III clinical studies are evaluating the therapeutic efficacy of metformin in the treatment of early and advanced breast cancer patients.

WITHDRAWN: Effect of obesity at the pathologic response to neoadjuvant chemotherapy among premenopausal Tunisian women with breast cancer

In this article, we evaluated BMI and response to neoadjuvant chemotherapy (NC) in premenopausal Tunisian women with operable breast cancer. From May 2006 to July 2009, 800 patients were diagnosed and received NC from CHU Farhat Hached (Sousse, Tunisia). Patients were categorized as obese (BMI >/=30 kg/m(2)), overweight (25 </= BMI < 30 kg/m(2)), or normal/underweight (BMI <25 kg/m(2)). Logistic regression was used to examine associations between BMI and pathologic complete response (pCR). Breast cancer-specific, progression-free, and overall survival times were examined using the Kaplan-Meier method and Cox proportional hazards regression analysis. Median age was 42 years; 27% of patients were obese, 25% were overweight, and 48% were normal or underweight. In the univariate model, there was a significant difference in pCR to NC for obese compared with normal/underweight patients. In multivariate analysis, there was no significant difference in pCR for obese compared to normal weight patients. Overweight and the combination of overweight and obese patients were significantly less likely to have a pCR (odds ratio (OR) = 0.59; 95% confidence interval (CI), 0.37-0.95; and OR = 0.67; 95% CI, 0.45-0.99, respectively). Higher BMI was associated with worse pCR to NC. So, its association with worse overall survival suggests that greater attention should be focused on this risk factor to optimize the care of breast cancer patients.

Obesity and angiolymphatic invasion in primary breast cancer

BACKGROUND

Obesity is associated with poorer breast cancer-specific survival. The purpose of this study was to investigate the relationships between obesity and the presence of angiolymphatic invasion as well as other features of invasive breast cancer, including stage at presentation, estrogen receptor (ER) status, triple-negative phenotype, and tumor grade.

METHODS

Detailed clinical and pathologic data were abstracted from the medical records of all 1,312 patients with stage I-III primary breast cancer who had breast surgery at the University of Michigan Comprehensive Cancer Center between January 1, 2000 and December 31, 2006. Bivariate and multivariate analyses were conducted to investigate the relationships between body mass index and tumor biologic features, controlling for menopausal status, diabetes and hypertension, hormone replacement therapy before diagnosis, race, and ethnicity.

RESULTS

In multivariate analyses, severe obesity was independently associated with the presence of angiolymphatic invasion [odds ratio (OR) 1.80, 95% confidence interval (CI) 1.08-2.99, joint test of significance, P = 0.03]. Severe obesity was associated with lower likelihood of triple-negative breast cancer (OR 0.39, 95% CI 0.16-0.96). Among premenopausal women with diabetes, ER-negative (OR 5.22, 95% CI 1.12-24.29) and triple-negative (OR 14.8, 95% CI 1.92-113.91) disease was significantly more common.

DISCUSSION

In this large sample of invasive breast cancers, obesity was independently associated with the presence of angiolymphatic invasion. Higher rates of angiolymphatic invasion among obese women may account in part for poorer outcomes among obese women with breast cancer.

Minireview: Obesity and breast cancer: the estrogen connection

There is now substantial evidence that overweight and/or obesity and/or weight gain are risk factors for the development of postmenopausal breast cancer. In addition, obesity and/or elevated body mass index at breast cancer diagnosis has a negative impact on prognosis for both premenopausal and postmenopausal women. Therefore, understanding the mechanism of how obesity affects the mammary tumorigenesis process is an important health issue. Elevated serum estrogen levels as well as enhanced local production of estrogen have been considered primary mediators of how increased body weight promotes breast cancer development in postmenopausal women. Here, we provide an overview of estrogen's relationship with both obesity and breast cancer as separate entities. Human and relevant preclinical studies are cited. In addition, other growth factors that may be involved in this relationship are considered.

Triple-negative breast cancer and obesity in a rural Appalachian population

BACKGROUND

Our objective was to determine the clinicopathologic features of triple-negative (estrogen receptor, progesterone receptor, and human epidermal growth factor-2 receptor negative) breast cancer and their relationship to obesity in women drawn from a population with one of the highest obesity rates in the United States.

METHODS

This retrospective study involved 620 White patients with invasive breast cancer in West Virginia. Hospital tumor registry, charts, and pathology records provided age at diagnosis, tumor histologic type, size, nodal status, and receptor status. Body mass index was calculated and a value of > or = 30 was considered indicative of obesity.

RESULTS

Triple-negative tumors occurred in 117 (18.9%) of the 620 patients, most often in association with invasive ductal carcinomas. Patients with triple-negative tumors were younger than those with other receptor types, 44.5% and 26.7%, respectively, being diagnosed at age <50 years (P = 0.0004). The triple-negative tumors were larger (P = 0.0003), most notably in the younger women, but small tumors (<2.0 cm) were more often accompanied by lymph node metastases. Obesity was present in 49.6% of those with triple-negative tumors but in only 35.8% of those with non-triple-negative tumors (P = 0.0098). Lymph node metastases were more frequently associated with T(2) tumors in obese patients (P = 0.032) regardless of their receptor status.

CONCLUSIONS

Triple-negative breast cancers within a White, socioeconomically deprived, population occurred in younger women, with later stage at diagnosis, and in association with obesity, which itself has been associated with a poor prognosis in breast cancer.

Relationship between obesity and pathologic response to neoadjuvant chemotherapy among women with operable breast cancer

PURPOSE

To understand the mechanism through which obesity in breast cancer patients is associated with poorer outcome, we evaluated body mass index (BMI) and response to neoadjuvant chemotherapy (NC) in women with operable breast cancer.

PATIENTS AND METHODS

From May 1990 to July 2004, 1,169 patients were diagnosed with invasive breast cancer at M. D. Anderson Cancer Center and received NC before surgery. Patients were categorized as obese (BMI >or= 30 kg/m(2)), overweight (BMI of 25 to < 30 kg/m(2)), or normal/underweight (BMI < 25 kg/m(2)). Logistic regression was used to examine associations between BMI and pathologic complete response (pCR). Breast cancer-specific, progression-free, and overall survival times were examined using the Kaplan-Meier method and Cox proportional hazards regression analysis. All statistical tests were two-sided.

RESULTS

Median age was 50 years; 30% of patients were obese, 32% were overweight, and 38% were normal or underweight. In multivariate analysis, there was no significant difference in pCR for obese compared with normal weight patients (odds ratio [OR] = 0.78; 95% CI, 0.49 to 1.26). Overweight and the combination of overweight and obese patients were significantly less likely to have a pCR (OR = 0.59; 95% CI, 0.37 to 0.95; and OR = 0.67; 95% CI, 0.45 to 0.99, respectively). Obese patients were more likely to have hormone-negative tumors (P < .01), stage III tumors (P < .01), and worse overall survival (P = .006) at a median follow-up time of 4.1 years.

CONCLUSION

Higher BMI was associated with worse pCR to NC. In addition, its association with worse overall survival suggests that greater attention should be focused on this risk factor to optimize the care of breast cancer patients.

Progesterone receptor expression is a marker for early stage breast cancer: implications for progesterone receptor as a therapeutic tool and target

We determined the association of estrogen receptor (ER) and progesterone receptor (PR) expression in invasive breast cancer with stage at diagnosis. Univariate analyses indicated that although ER and PR expression were inversely associated with grade (P<0.0001), only PR expression (P<0.01) was inversely associated with stage. Multivariate analyses, adjusted for covariates, including HER-2/neu expression, indicated that PR (odds ratio (OR), 0.88; confidence interval (CI), 0.77-0.99; P=0.03) and not ER expression (OR, 1.04; CI, 0.94-1.16; P=0.45) was inversely associated with stage. PR and not ER expression is a marker for early stage breast cancer.

Receipt of appropriate primary breast cancer therapy and adjuvant therapy are not associated with obesity in older women with access to health care

PURPOSE

Many studies have reported body mass index (BMI) increases the risk of breast cancer recurrence and breast cancer-specific mortality. Few studies have reported or examined whether breast cancer treatment differs by BMI. The purpose of this study was to examine the association between BMI at breast cancer diagnosis and receipt of appropriate primary tumor therapy and adjuvant therapy.

METHODS

We identified 897 women age >or= 65 years diagnosed with stage I or II breast cancer from 1990 to 1999 at five health care organizations. We used medical records to confirm demographics, tumor characteristics, treatment, comorbid conditions, and to calculate BMI at diagnosis (< 25 kg/m(2), n = 328; 25 to < 30 kg/m(2), n = 305; 30 to < 35 kg/m(2), n = 188; >or= 35 kg/m(2), n = 76). We defined primary therapy based on National Guidelines as receiving breast-conserving surgery with radiation therapy and axillary node dissection, simple mastectomy with axillary node dissection, or modified radical mastectomy (73% overall); adjuvant therapy was defined as receipt of hormonal therapy, chemotherapy, or both (60% overall).

RESULTS

The median BMI was 26.7 kg/m(2) (range, 14.6 to 61.2). The proportion of women receiving primary therapy and adjuvant therapy was lowest for women less than 25 kg/m(2) (69% and 56%, respectively) and greatest for obese I (78% and 64%, respectively). There were no differences in receipt of primary or adjuvant treatment across BMI in univariate or multivariable models (after adjusting for age, stage, comorbidity, diagnosis year, and hormone receptor positivity).

CONCLUSION

Receipt of appropriate primary therapy and adjuvant therapy is not associated with BMI in older women with access to health care. Additional research in larger samples and more diverse settings is needed.

Body Mass Index Influences Palpability but not Stage of Breast Cancer at Diagnosis

Body mass index (BMI) is associated with breast cancer risk, but its relationship with stage at diagnosis is unclear. BMI was calculated for patients in the North American Fareston and Tamoxifen Adjuvant trial, and was correlated with clinicopathologic factors, including stage at diagnosis. One thousand eight hundred fourteen patients were enrolled in the North American Fareston and Tamoxifen Adjuvant study; height and weight were recorded in 1451 (80%) of them. The median BMI was 27.1 kg/m2 (range, 14.7–60.7). The median patient age was 68 years (range, 42–100); median tumor size was 1.3 cm (range, 0.1–14 cm). One thousand seven hundred ninety-three (99.0%) patients were estrogen receptor positive, and 1519 (84.7%) were progesterone receptor positive. There was no significant relationship between BMI (as a continuous variable) and nodal status ( P = 0.469), tumor size ( P = 0.497), American Joint Committee on Cancer stage ( P = 0.167), grade ( P = 0.675), histologic subtype ( P = 0.179), or estrogen receptor status ( P = 0.962). Patients with palpable tumors, however, had a lower BMI than those with nonpalpable tumors (median 26.4 kg/m2 vs 27.5 kg/m2, P < 0.001). Similar results were found when BMI was classified as a categorical variable (<25 vs 25–29.9 vs ≥30). Increased BMI does not lead to a worse stage at presentation. Obese patients, however, tend to have nonpalpable tumors. Mammography in this population is especially important.

Obesity as a risk factor for development and poor prognosis of breast cancer

The evidence that obesity adversely affects women's health is overwhelming and indisputable. The risk of postmenopausal breast cancer increases with obesity; measured as weight gain, body mass index, waist-hip ratio or percent body fat. It is also established that obesity is associated with poor prognosis of breast cancer. This review examines in detail the possible mechanisms by which obesity causes poor prognosis of breast cancer such as estrogenic activity, advanced or more aggressive disease at diagnosis and high likelihood of both local and systemic treatment failure. After careful consideration of the available evidence, the author concludes that obesity contributes towards development and poor prognosis of breast cancer; therefore, weight management should be an integral part of any strategy to prevent and improve the outcome of breast cancer.

Angiogenic factors are elevated in overweight and obese individuals

BACKGROUND

Adipose tissue produces both vascular growth factors and inhibitors. Since obesity is associated with expansion of the capillary bed in regional adipose depots the balance between these factors may favor angiogenesis.

OBJECTIVE

To investigate the relationship between body mass index and serum concentrations of vascular growth factors in human subjects.

METHODS

Vascular endothelial growth factor (VEGF), VEGF-C, VEGF-D, soluble VEGF receptor-2 (sVEGFr2), hepatocyte growth factor (HGF), angiopoietin-2, angiogenin and endostatin concentrations were measured in serum collected from 58 lean (24 males, 34 female, mean BMI, 22.2+/-0.3) and 42 overweight and obese (16 males and 26 females, mean BMI, 33.5+/-1.2) subjects after an overnight fast.

RESULTS

Sexual dimorphism was apparent in the serum concentrations of VEGF-C, VEFG-D and angiopoietin-2 with significantly higher levels in female compared to male subject. VEGF, VEGF-C, VEGF-D, soluble VEGF receptor-2, angiopoietin-2, angiogenin and endostatin but not HGF were significantly elevated in overweight and obese subjects. Positive correlations between BMI and the serum concentrations of VEGF-C, VEGF-D, sVEGF-R2, angiopoietin-2, angiogenin and endostatin were observed even after adjustment for gender and age.

CONCLUSIONS

Increased levels of vascular growth factors as well as the angiogenesis inhibitor endostatin are present in overweight and obese subjects and may contribute to previously documented increased risk of metastatic disease in obese subjects with cancer.

Effect of obesity on presentation of breast cancer

BACKGROUND

Obesity has been shown to be associated with reduced survival in patients with invasive breast cancer (IBC), although the mechanisms for this finding are unclear. The objective of this study was to examine the effect of obesity on the presentation and pathologic staging of IBC.

METHODS

From February 15, 2002, to February 15, 2004, all patients undergoing surgery for primary IBC at two institutions were enrolled in a prospective cohort study. National Institutes of Health criteria were used to categorize patients: normal or underweight (NW; body mass index <25 kg/m(2)), overweight (OW; body mass index 25-29.9 kg/m(2)), and obese or severely obese (OB; body mass index > or =30 kg/m(2)). Presentation and pathologic factors were then compared among groups.

RESULTS

The study cohort consisted of 519 patients; 166 (32%) were NW, 177 (34%) were OW, and 176 (34%) were OB. OW (46%) and OB (39%) patients were more likely to be diagnosed with IBC via screening mammography compared with NW (31%) patients (P = .01), although no differences were found between groups with respect to previous use of screening mammography. Aggressive pathologic features, including lymph node metastases, advanced tumor-node-metastasis stage, and grade were found more commonly among OB patients.

CONCLUSIONS

OW and OB patients were more likely to receive a diagnosis via screening mammography, thus suggesting that mammography may play a more important role in OW and OB patients. Despite this, OB patients presented with larger, more advanced tumors; this may help to explain obesity-associated survival differences in IBC patients. This is important information given the prevalence of obesity in North America.

Adult weight gain and histopathologic characteristics of breast cancer among postmenopausal women

BACKGROUND

Although the link between postmenopausal breast cancer and adiposity is well established, the association between weight gain and specific histopathologic characteristics of breast carcinoma has not been studied carefully.

METHODS

Using 1200 incident invasive breast cancers among 44,161 postmenopausal women who were not taking hormone therapy in the American Cancer Society's Cancer Prevention Study II Nutrition Cohort, the authors computed age-adjusted rates and rate ratios (RR) for breast cancer by histology, stage, grade, and estrogen receptor (ER) and progesterone receptor (PR) status by categories of adult weight gain.

RESULTS

Age-adjusted rates of breast cancer were highest for women who reported the most weight gain, regardless of histologic type. For weight gain >60 pounds, compared with weight gain < or =20 pounds the RR for ductal carcinoma was 1.89 (95% confidence interval [95%CI], 1.53-2.34), and the RR for lobular carcinoma was 1.54 (95%CI. 1.01-2.33). Weight gain was associated with increased risk at every tumor stage and grade. The risk for regional or distant stage was elevated significantly in every category of weight gain and was 3 times higher among women who had the greatest weight gain (RR, 3.15; 95%CI, 2.21-4.48). Weight gain was associated with increased risk of ER-positive/PR-positive tumors (P for trend <.0001) but not ER-negative/PR-negative tumors (P for trend = .09). The results essentially remained unchanged when the analysis was restricted to women who had regular screening mammograms.

CONCLUSIONS

Excess adiposity is an important contributor to breast cancer risk among postmenopausal women, regardless of histologic type, and especially for tumors of advanced stage and high grade.

Genetic and environmental correlations between bone phenotypes and anthropometric indices in Chinese

Height, weight, bone mineral density (BMD), and bone size are all influenced by genetic and environmental factors as well as interactions between them. Height and weight are often used in population studies to adjust the bone phenotypes. However, it is still unknown what proportion of genetic and environmental variability is shared between these anthropometric characteristics and the bone phenotypes. The genetic and environmental correlations between the bone phenotypes and anthropometric indices in Chinese subjects were studied by bivariate quantitative genetic analysis on a sample of 931 healthy subjects from 292 Chinese nuclear families aged from 19 to 79 years. BMD and bone size at the lumbar spine (L1-L4) and the hip of all subjects were measured by dual-energy X-ray absorptiometry. We found significant genetic correlations between weight and spine BMD, hip BMD, spine bone size and hip bone size, which were 0.50 (P<0.01), 0.45 (P<0.01), 0.36 (P=0.02), and 0.38 (P<0.01), respectively. Likewise, significant genetic correlations between height and spine BMD, spine bone size, and hip bone size were 0.30 (P=0.02), 0.54 (P<0.01), and 0.58 (P<0.01), respectively. The environmental correlations were found to be significant only between height and spine bone size (P<0.001) and weight and hip BMD (P=0.02). These results suggest the probability that the same genetic and environmental factors contribute to these different phenotypes. Moreover, when a candidate gene or genomic region is responsible for the variation of both bone phenotypes and anthropometric indices, its true genetic effect on the bone phenotypes may be lost after one has adjusted the phenotypic values with weight and height as random environmental factors. It may have implications for population studies of candidate genes that underlie the complex bone phenotypes and for the development of strategies for therapeutic application.

The associations of obesity, lymph node status and prognosis in breast cancer patients: dependence on estrogen and progesterone receptor status

Breast cancer patients who are obese have a higher risk of lymph node metastases and a poorer prognosis than those who are slim. It has been claimed that estrogens derived from fat are important for these associations. If estrogens are important, these relationships must be stronger in the hormone receptor-positive than in the hormone receptor-negative groups. Body mass index (BMI) was used as a measure of obesity. The second, third, and fourth quintiles of BMI were treated as one group and termed 'medium'. Patients in the fifth quintile were termed 'obese' and those in the first quintile 'slim'. The number of women with unilateral disease treated with modified radical mastectomy and included in the study was 1211. Of all patients included, obese patients had a 1.53 higher risk of lymph node metastases compared to slim patients (p=0.02). In the PgR-negative group, obesity gave a 3.08 times higher risk of lymph node metastases (p=0.03). The risk of dying of breast cancer tended to be higher in obese than in slim patients when all patients in the study were compared (relative risk=1.38, p=0.06). BMI did not show a statistically significant relationship with prognosis if only hormone receptor status was considered. However, if lymph node status and hormone receptor status were taken together, the association was strong and reversed in the lymph node-positive group with ER-negative tumours. The adjusted relative risk was 0.33, showing that slim patients had a 3.03 (1.0/0.33) times higher risk of dying of breast cancer compared to obese patients (p=0.002). These results indicate that non-hormonal mechanisms could be important.

Predictive Modelling of Post-onset Xenoma Growth During Microsporidial Gill Disease (Loma salmonae) of Salmonids

Loma salmonae, an obligate intracellular microsporidian parasite, is the causal agent of microsporidial gill disease of salmon (MGDS), characterized by the production, growth and eventual rupture of spore-filled xenomas. MGDS in farmed chinook salmon remains occult until xenoma rupture, at which time the infected fish respond with intense branchitis and high rates of mortality. The present study showed that in experimentally infected fish the rate of change of xenoma diameter could be modelled through regression analysis, particularly through the period of 4-9 weeks post-infection, yielding the predictive equation: xenoma diameter=-42.9 microns +15.3 microns x (number of weeks post-infection). This provides a tool for diagnosticians to predict the time to xenoma rupture and hence to the initiation of the clinical phase of MGDS.

Obesity, adipocytokines, and insulin resistance in breast cancer

The adipocytokines are biologically active polypeptides that are produced either exclusively or substantially by the adipocytes, and act by endocrine, paracrine, and autocrine mechanisms. Most have been associated with obesity, hyperinsulinaemia, type 2 diabetes, and chronic vascular disease; in addition, six adipocytokines--vascular endothelial growth factor, hepatocyte growth factor, leptin, tumour necrosis factor-alpha, heparin-binding epidermal growth factor-like growth factor, and interleukin-6--promote angiogenesis while one, adiponectin, is inhibitory. Obesity and insulin resistance have both been identified as risk factors for breast cancer and are associated with late-stage disease and poor prognosis. Angiogenesis is essential for breast cancer development and progression, and so it is plausible that obesity-related increases in adipocytokine production and a reduction in adiponectin may adversely affect breast cancer outcome by their angiogenesis-related activities. There is also experimental evidence that some adipocytokines can act directly on breast cancer cells to stimulate their proliferation and invasive capacity. Thus, adipocytokines may provide a biological mechanism by which obesity and insulin resistance are causally associated with breast cancer risk and poor prognosis. Both experimental and clinical studies are needed to develop this concept, and particularly in oestrogen-independent breast cancers where preventive and therapeutic options are limited.

Obesity and breast cancer: a review of the literature

A woman's build, the risk of breast cancer and its subsequent prognosis seem to be related. In most but not all case-control and prospective cohort studies, an inverse relationship has been found between weight and breast cancer among premenopausal women. However, most large epidemiological studies have found that overweight or obese women are at increased risk of developing postmenopausal breast cancer. It is suggested that higher body mass index is associated with a more advanced stage of breast cancer at diagnosis in terms of tumour size but data on lymph node status is not so consistent. All treatment modalities for breast cancer such as surgery, radiotherapy, chemotherapy and hormonal treatment may be adversely affected by the presence of obesity. The overall and disease-free survival is worse in most but not all studies of prognosis of obese pre- and postmenopausal women with breast cancer.

Does obesity compromise survival in women with breast cancer?

Obesity, measured by high body mass index (BMI >30 kg/m2) is associated with an increased risk of postmenopausal breast cancer but the effect of obesity on prognosis is not clear. A prospectively accrued and regularly validated database of 1579 patients with breast cancer treated in a district general hospital between 1963 and 1999 was analysed for clinical and pathological tumour characteristics including the family history, grade, tumour type, treatment and outcome. The risk factors and outcome of obese and non-obese patients were compared. Breast cancer in obese women was associated with significantly larger tumour size and worse Nottingham prognostic index. There was no statistically significant difference in overall and disease-free survival between obese and non-obese group. Hazard ratios (95% Cl) were 0.81 (0.62-1.06) and 0.80 (0.63-1.01), respectively. In the present study, obesity is not an indicator of worst prognosis of breast cancer.

Insulin and cancer

Obesity has recently been linked to mortality from the majority of cancers. The insulin/insulin-like growth factor (IGF) system may partly explain this effect. The metabolic syndrome, associated with hyperinsulinemia, may modulate this effect. Recent evidence supports the role of insulin and IGF-1 as important growth factors, acting through the tyrosine kinase growth factor cascade in enhancing tumor cell proliferation. In addition, the metabolic syndrome associated with a chronic inflammatory state and accompanying cytokine abnormalities may also contribute to tumor progression. Growing links between insulin and the etiology as well as prognosis in colon, prostate, pancreatic, and, particularly, breast cancer are reviewed. Of particular concern is the evidence that elevated IGF-1 may interfere with cancer therapy, adversely affecting prognosis. The role of insulin is of concern because of the increasing levels of obesity and the associated metabolic syndrome. Weight gain, through typical Western diet; limited levels of activity; and, more recently, stress-related changes in neuroendocrine function may lead to insulin resistance and hyperinsulinemia. The opportunity for a multidisciplinary approach involving nutrition, exercise, and stress reduction in an integrative setting may be crucial to limiting the insulin-resistant state and improving cancer outcomes.

Breast cancer and obesity: an update

Obesity has a complicated relationship to both breast cancer risk and the clinical behavior of the established disease. In postmenopausal women, particularly the elderly, various measures of obesity have been positively associated with risk. However, before menopause increased body weight is inversely related to breast cancer risk. In both premenopausal and postmenopausal breast cancer, the mechanisms by which body weight and obesity affect risk have been related to estrogenic activity. Obesity has also been related to advanced disease at diagnosis and with a poor prognosis in both premenopausal and postmenopausal breast cancer. Breast cancer in African-American women, considering its relationship to obesity, exhibits some important differences from those described in white women, although the high prevalence of obesity in African-American women may contribute to the relatively poor prognosis compared with white American women. Despite the emphasis on estrogens to explain the effects of obesity on breast cancer, other factors may prove to be equally or more important, particularly as they relate to expression of an aggressive tumor phenotype. Among these, this review serves to stress insulin, insulin-like growth factor-I, and leptin, and their relationship to angiogenesis, and transcriptional factors.