Impact of obesity on diagnosis and treatment of breast cancer

Does body mass index influence surgical options and overall survival in breast cancer patients?

Obesity is a relevant risk factor in breast cancer (BC), but little is known about the effects of overweight and obesity in surgical outcomes of BC patients. The aim of this study is to analyse surgical options and associated overall survival (OS) in overweight and obese women with BC. In this study, 2143 women diagnosed between 2012 and 2016 at the Portuguese Oncology Institute of Porto (IPO-Porto) were included, and the clinicopathological information was retrieved from the institutional database. Patients were stratified by body mass index (BMI). Statistical analysis included Pearson's chi-squared test with statistical significance set at p < 0.05. Multinomial, binary logistic regression and cox proportional-hazards model were also performed to calculate odd ratios and hazard ratios with 95% confidence intervals for adjusted and non-adjusted models. The results revealed no statistical difference in histological type, topographic localization, tumour stage and receptor status and in the number of surgical interventions. Overweight women have increased probability to be subjected to sentinel node biopsy. Obese and overweight women are more likely to be submitted to conservative surgery and contrariwise, less likely to undergo total mastectomy. Patients submitted to conservative surgery and not submitted to total mastectomy had a favourable OS although without statistical significance. No significant differences were observed in OS when stratified by BMI. Our results revealed significant variations regarding the surgical options in overweight and obese patients, but these were not translated in OS difference. More research is recommended to better address treatment options in overweight and obese BC patients.

Endoscopic submucosal dissection for papillary early gastric carcinoma: Insights from a large-scale analysis of post-gastrectomy pathology specimens

Gastric papillary adenocarcinoma is considered a differentiated adenocarcinoma in the current endoscopic submucosal dissection indication guidelines. However, the safety of endoscopic submucosal dissection remains controversial. Currently, data regarding which papillary early gastric cancer should be considered for endoscopic submucosal dissection are unavailable. Thus, the aim of this study was to investigate lymph node metastasis and the safety of endoscopic submucosal dissection in patients with papillary early gastric cancer. This observational study recruited 4264 consecutive patients with early gastric cancer who underwent curative gastrectomy between October 2000 and December 2017 at the National Cancer Center, Korea. Of these, 45 had pathologically confirmed papillary early gastric cancer, 2106 had differentiated non-papillary early gastric cancer, and 2113 had undifferentiated early gastric cancer. Logistic regression analysis was performed to identify risk factors for lymph node metastasis. Mucosal tumors were less common in papillary early gastric cancer (37.9%) than in differentiated non-papillary early gastric cancer (48.8%) and undifferentiated early gastric cancer (60.4%) (both P < .001). Lymph node metastasis was more common in papillary early gastric cancer (20.0%) than in differentiated non-papillary early gastric cancer (9.2%) and undifferentiated early gastric cancer (11.7%; both P < .001). In multivariate analysis, non-mixed-type papillary early gastric cancer showed marginally increased odds of lymph node metastasis than differentiated early gastric cancer (odds ratio [OR]: 2.5, 95% confidence interval [CI]: 1.0-6.3). Rates of lymph node metastasis (1/10, 10%) and angiolymphatic invasion (2/10, 20%) for papillary early gastric cancer meeting expanded criteria were higher than those for other histology types meeting endoscopic submucosal dissection absolute or expanded criteria (P = .03 and P < .001, respectively). Endoscopic submucosal dissection should be considered carefully for papillary early gastric cancer, especially if it meets expanded endoscopic submucosal dissection indications since it is associated with high rates of submucosal invasion and lymph node metastasis.

Association Between Obesity and Clinicopathological Profile of Patients with Newly Diagnosed Non-Metastatic Breast Cancer in Saudi Arabia

Purpose

Obesity is prevalent in Saudi Arabia and is associated with adverse clinical features and poor breast cancer (BC) outcomes. We determined the distribution of body mass index (BMI) and evaluated its association with disease characteristics and outcomes in women with non-metastatic BC.

Patients and Methods

We conducted a retrospective analysis of a prospectively collected database of consecutive patients treated for non-metastatic BC between 2002 and 2014. Patients were categorized into the following groups: underweight/normal weight (BMI <25 kg/m²), overweight (BMI 25–29.9 kg/m²), and obese (BMI ≥30 kg/m²). Regression analysis was used to evaluate clinicopathological factors associated with BMI and clinical stage.

Results

A total of 2212 patients were enrolled. The median age was 45 years (interquartile range [IQR], 39–52 years), and the median BMI was 30 kg/m² (IQR, 26–34 kg/m²). Most patients were premenopausal (63.6%), nearly half of the patients had stage III disease, and 11.2% were screen-detected. The prevalence of obesity was 53.4%, with a significant difference between the peri/premenopausal (49.4%) and postmenopausal (61.7%) groups (p < 0.001). Obese patients were more likely to be aged >40 years, be postmenopausal, have a history of oral contraceptive pills, have advanced-stage disease, and have undergone radiation therapy, and were less likely to have human epithelial growth factor 2 (HER2)+ disease than non-obese patients. Premenopausal obese women had fewer hormone receptor-positive and more triple-negative cancers than postmenopausal obese women did. Obesity, non-screening-detected BC, and HER+ status were independent prognostic factors for advanced-stage presentation.

Conclusion

The prevalence of obesity and its significant association with advanced BC justify the upscaling of screening services and instituting weight-reduction strategies.

The Relationship Between Body Mass Index and Different Regional Patterns of Lymph Node Involvement in Papillary Thyroid Cancers

Introduction

Lymph node (LN) metastasis is the first site of metastasis of papillary thyroid cancer (PTC). LN status influences clinical management and the prognosis of patients. We explored the relationship between patient obesity and regional patterns of LN involvement in PTC.

Materials and Methods

This study retrospectively analyzed the data from 12,772 PTC patients. The rate of LN metastasis, number of LN metastasis, maximum diameter of positive LN, number of dissected LN, and LN ratios (LNR) were compared between normal-weight and obese patients. Statistical methods have been adjusted for the confounders in hypothesis testing.

Results

Overweight and obesity were independent risk factor for metastatic LNs (OR₁ = 1.125, 95% CI 1.042-1.214, P₁ = 0.003; OR₂ = 1.554, 95% CI 1.339-1.802, P₂<0.001). Obesity was an independent risk factor for the number of metastatic CLNs (OR=1.159, 95% CI 0.975-1.377, P=0.045), however not for number of metastatic lateral LNs (P=0.907). Furthermore, obesity was not an independent risk factor for number of CLNs when dissected more than five (P=0.653), still an independent risk factors for number of metastatic lateral LNs when more than six (OR=1.185, 95% CI 1.010-1.391, P=0.037). As for LNR, obesity was an independent risk factor for the central LNR when more than 0.12 (OR _{adjusted 1} = 1.099, 95% CI 1.011-1.194, P₁ = 0.027; OR _{adjusted 2} = 1.177, 95% CI 1.003-1.381, P₂ = 0.045), for the lateral LNR more than 0.05 (P₂ = 0.283).

Conclusions

Obesity was associated with poor prognoses with PTC respecting LNs. Surgeons should be extreme caution when performing central neck dissection in obese patients.

The Effect of Body Mass Index on Initial Breast Cancer Stage Among Korean Women

BACKGROUND

The relationship between obesity and breast cancer stage is not well-known in the Korean population. This study aimed to identify the effect of body mass index (BMI) on initial breast cancer stage.

PATIENTS AND METHODS

Among patients who underwent surgery for breast cancer (stages 0-III) from June 2003 to December 2018, we analyzed 4510 patients for whom there were BMI data.

RESULTS

The average BMI of our patients was 23.5 (14.2-44.9). In total, 4.6% and 24.2% of the patients had a BMI of ≥30 and 25-29.9, respectively. In the patients with obesity, the proportion of T2 to T4 was 41.4%, which was higher than that in patients with a BMI of 25 to 29 (28.4%; P = .001) or a BMI of <25 (23.3%; P < .001). There was no difference in positive rates of estrogen receptor and progesterone receptor with BMI, but obese patients were less likely to be human epidermal growth factor receptor 2 positive. Patients with higher stages were more likely to have a higher BMI. The effect of BMI on stage was stronger in patients <50 years (odds ratio, 2.439; 95% CI, 1.783-3.335). Although there was no statistical significance, tumors >2 cm were less likely to be palpable in obese patients than in patients of normal weight (nonpalpable in 33.8% and 27.0%, respectively).

CONCLUSION

Our study suggests that obesity is associated with a more advanced breast cancer stage, which represents a poor prognosis, and large tumors tend to be less palpable in women with obesity.

Prognostic implications of visceral obesity on gastric adenocarcinoma: does it really matter?

PURPOSE

To evaluate the association of visceral adiposity measured on computed tomography (CT) in preoperative period with lymph node (LN) metastasis and overall survival in gastric adenocarcinoma patients.

METHODS

Preoperative CT scans of 246 gastric adenocarcinoma patients who did not receive neoadjuvant chemoradiotherapy were evaluated. Visceral fat area (VFA), subcutaneous fat area (SFA) and Total fat area (TFA), VFA/TFA ratio were quantified by CT. VFA/TFA > 29% was defined as visceral obesity. The differentiation, t-stage, n-stage and the number of harvested-metastatic LNs were noted. The maximum thickness of tumor and localization were recorded from CT. Chi-square, Student's t-test, multiple Cox regression, Spearman's correlation coefficient, and Kaplan-Meier algorithm were performed.

RESULTS

The overall survival (OS) rates and N-stage were not different significantly between viscerally obese and non-obese group (p = 0.994, p = 0.325). The number of metastatic LNs were weakly inversely correlated with VFA (r = -0.144, p = 0.024). Univariate analysis revealed no significant association between visceral obesity and OS or LN metastasis (p = 0.377, p = 0.736). In multivariate analyses, OS was significantly associated with poorly differentiation (HR = 1.72, 95% CI =1.04-2.84, p = 0.035), higher pathologic T and N stage (T4 vs T1 + T2 HR = 2.67, 95% CI =1.18-6.04, p = 0.019; T3 vs T1 + T2 HR = 1.98, 95% CI = 0.90-4.33, p = 0.089; N3b vs N0 HR = 2.97, 95% CI1.45-6.0, p = 0.003; N3 (3a+ 3b) vs N0 HR = 2.24 95% CI =1.15-4.36, p = 0.018).

CONCLUSION

Visceral obesity may not be a prognostic factor in resectable gastric adenocarcinoma patients.

Relationship between body mass index and malignancy rates of MRI-guided breast biopsies: impact of clinicodemographic factors

PURPOSE

To determine the positive predictive value (PPV) of magnetic resonance imaging (MRI)-guided breast biopsy stratified by body mass index (BMI). Secondary endpoints include evaluation of indications for breast MRI and identification of factors associated with malignant biopsy.

METHODS

We retrospectively analyzed results of MRI-guided breast biopsies in a consecutive cohort of women at a single institution between 2014 and 2019. The PPV was compared between BMI subgroups and the overall group by the one-sample z-test. Factors associated with malignant biopsy were analyzed using multivariate regression analysis.

RESULTS

Among 427 MRI-guided breast biopsies, the PPV was significantly higher in patients with a BMI ≥ 35 compared to BMI < 35 (38.6% versus 24.5%, p = 0.043). This remained true in the 180 biopsies from high-risk screening studies, but there was no difference in PPV by BMI in the 205 biopsies performed to evaluate extent of known disease. Among this cohort who underwent MRI-guided breast biopsy, the underlying indication for MRI was less likely to be high-risk screening in those with a higher BMI or Black or Hispanic race (p = 0.015 and p < 0.001, respectively). For high-risk screening studies, only BMI ≥ 35 was associated with malignant biopsies (OR 37.5, p = 0.003). For evaluation of extent of disease studies, only increased lesion size was a significant predictor of malignant result (OR 1.01, p = 0.04).

CONCLUSIONS

Among women who underwent MRI-guided breast biopsy, elevated BMI was associated with increased PPV and malignant biopsies. Patients with a higher BMI or Black or Hispanic race who had MRI-guided biopsy were less likely to be undergoing high-risk screening and more likely to have breast MRI to evaluate extent of known disease.

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

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

Is There a Bias Against Obese Patients in the Treatment of Breast Cancer?

BACKGROUND

Patient and tumor characteristics often coincide with obesity, potentially affecting treatment decision-making in obese breast cancer patients. Independent of all of these factors, however, it is unclear whether obesity itself impacts the decision to offer patients undergoing mastectomy breast reconstruction, postmastectomy radiation therapy (PMRT), or neoadjuvant chemotherapy. We sought to determine whether implicit bias against obese breast cancer patients undergoing mastectomy plays a role in their treatment.

METHODS

Medical records of breast cancer patients undergoing mastectomy from January 2010 to April 2018 from a single institution were retrospectively reviewed, separated into obese (BMI ≥30) and nonobese (BMI <30) categories, and compared using nonparametric statistical analyses.

RESULTS

Of 972 patients, 291 (31.2%) were obese. Obese patients were more likely to have node-positive, triple-negative breast cancers (P = .026) and were also more likely to have other comorbidities such as a history of smoking (P = .026), hypertension (P < .001), and diabetes (P < .001). Receipt of immediate reconstruction and contralateral prophylactic mastectomy did not vary between obese and nonobese patients. While obese patients were more likely to undergo neoadjuvant chemotherapy (26.5% vs. 18.1%, P = .004) and PMRT (33.0% vs. 23.4%, P = .003), this did not remain significant when controlling for comorbidities and clinicopathologic confounders.

CONCLUSION

Obese patients present with more aggressive tumors and often have concomitant comorbidities. Independent of these factors, however, differences in the treatment of patients undergoing mastectomy do not seem to be affected by an implicit bias against obese patients.

Do Obese Breast Cancer Patients Have More Complications and a Longer Length of Stay After Mastectomy Than Nonobese Patients?

BACKGROUND

While obesity is thought to increase complication rates in general surgery procedures, its effect in mastectomy patients remains to be fully elucidated. We sought to determine if obesity is associated with a higher complication rate and length of stay after mastectomy, independent of clinicopathologic and treatment factors.

METHODS

Medical records of breast cancer patients undergoing mastectomy at our institution between January 2010 and December 2017 were retrospectively reviewed. Patients were separated into obese (body mass index [BMI] ≥ 30) and nonobese (BMI < 30) categories and compared using nonparametric statistical analyses.

RESULTS

Of 927 patients, 291 (31.2%) were obese. Obese patients had more complications (26.5% vs. 20.0%, P = 0.033) and a greater number of complications per patient (P = 0.025) than nonobese patients. They were more likely to have infections (10.7% vs. 5.7%, P = .009), flap thrombosis/necrosis (5.5% vs. 2.4%, P = .018), and skin breakdown/wound complications (8.6% vs. 4.6%, P = .022). Additionally, obese patients had longer hospital length of stay (LOS; LOS > 2 days: 77.7% vs. 65.2%, P < .001). Controlling for potential confounders, obesity remained associated with a higher rate of thrombosis/necrosis of flap (odds ratio [OR] = 2.26; 95% confidence interval [CI] 1.01-5.08; P = .047) and LOS ≥ 2 days (OR = 1.82; 95% CI 1.23-2.69; P = .003).

CONCLUSION

Obese breast cancer patients undergoing mastectomy have more thrombosis/necrosis of flap and a longer hospital LOS than nonobese patients, regardless of other comorbidities and clinicopathologic/treatment factors.

Obesity and mortality after locoregional breast cancer diagnosis

PURPOSE

Higher mortality after a breast cancer diagnosis has been observed among women who are obese. We investigated the relationships between body mass index (BMI) and all-cause or breast cancer-specific mortality after a diagnosis of locoregional breast cancer.

METHODS

Women diagnosed in 2004 with AJCC Stage I, II, or III breast cancer (n = 5394) were identified from a population-based National Program of Cancer Registries (NPCR) patterns of care study (POC-BP) drawing from registries in seven U.S. states. Differences in overall and breast cancer-specific mortality were investigated using Cox proportional hazards regression models adjusting for demographic and clinical covariates, including age- and stage-based subgroup analyses.

RESULTS

In women 70 or older, higher BMI was associated with lower overall mortality (HR for a 5 kg/m² difference in BMI = 0.85, 95% CI 0.75-0.95). There was no significant association between BMI and overall mortality for women under 70. BMI was not associated with breast cancer death in the full sample, but among women with Stage I disease; those in the highest BMI category had significantly higher breast cancer mortality (HR for BMI ≥ 35 kg/m² vs. 18.5-24.9 kg/m² = 4.74, 95% CI 1.78-12.59).

CONCLUSIONS

Contrary to our hypothesis, greater BMI was not associated with higher overall mortality. Among older women, BMI was inversely related to overall mortality, with a null association among younger women. Higher BMI was associated with breast cancer mortality among women with Stage I disease, but not among women with more advanced disease.

[Outcomes of patients with breast cancer in function of their body mass index]

OBJECTIVE

The aim of this study was to evaluate outcomes of patients with breast cancer in function of the body mass index (BMI).

METHODS

The study cohort consisted of consecutive women undergoing surgery for breast cancer in our institution between January 2009, and September 2013. Individual records of all patients were reviewed and analyzed. Patient BMI was categorized as underweight, normal, overweight and obese.

RESULTS

A total of 1599 patients were evaluated. Patients were followed for one to 265months with a mean of 36.4months. The number of patients in each of the BMI categories was 66, 779, 463 and 291 for underweight, normal, overweight and obese women respectively. Women with higher BMI were more frequently affected by hypertension (18, 21, 35 and 47% respectively, P<0.0001) and diabetes (3, 2, 7 and 7% respectively, P<0.0001). Obese women had more frequently an inflammatory presentation (P=0.006), larger tumour size (P=0.038) and axillary lymph node involvement (P=0.03) with much more positive lymph nodes (P=0.02). Patients had the same protocols of treatment (surgery and adjuvant treatment). There was no statistically significant difference in overall 5-years survival between groups (P=0.30).

CONCLUSIONS

Our study demonstrate a more aggressive clinical and histological presentation for obese women with breast cancer.

Impact of central obesity on prognostic outcome of triple negative breast cancer in Chinese women

Purpose

To evaluate the prognostic effect of central obesity on triple negative breast cancer (TNBC).

Methods

206 TNBC patients treated from June 2006 to June 2015 were enrolled retrospectively. Body mass index (BMI) ≥25 kg/m² was the standard of obesity and waist circumference ≥80 cm was the standard of central obesity. Patient and tumor characteristics were compared between obesity categories. Survival differences between obesity categories were assessed with log-rank test in the univariate analysis and prognostic factors were then investigated by Cox regression analysis.

Results

81 cases were with obesity (39.3 %). 71 cases were with central obesity (34.5 %). Patients with obesity or central obesity tended to be older (P = 0.022 for obesity; P = 0.013 for central obesity) and to have larger tumor size (P = 0.027 for obesity; P = 0.027 for central obesity). By Cox regression analysis, central obesity (DFS: HR 1.759; 95 % CI 1.009–3.065; P = 0.046. OS: HR 2.297; 95 % CI 1.184–4.456; P = 0.014) was identified as an independent prognostic factor. For central obesity with BMI ≥ 25 kg/m², the prognostic effect was more apparent (DFS: HR 1.845; 95 % CI 1.059–3.212; P = 0.031. OS: HR 2.377; 95 % CI 1.230–4.593; P = 0.010).

Conclusion

Central obesity, especially with high BMI, was an independent prognostic factor for TNBC.

Visceral Obesity is Associated with Poor Prognosis in Pancreatic Adenocarcinoma

An association between obesity and unfavorable outcomes for various types of malignancy has been established. Nevertheless, the impact of visceral obesity (VO) on outcomes in pancreatic cancer is still unknown and controversial. The aim of this study was to uncover an association between VO and pancreatic cancer outcomes. We retrospectively reviewed 499 patients with pancreatic cancer who were diagnosed and treated in Severance Hospital from January 2006 to December 2011. Compared to the low-VO group (n = 260), the high-VO group (n = 239) was mostly male (68.2% vs. 31.8%, P < 0.001) and was more likely to have current smoking status (29.7% vs. 17.7%, P < 0.001), current alcohol intake status (52.3% vs. 26.4%, P < 0.001) and diabetes mellitus (54.4% vs. 31.9%, P = 0.028). The progression free survival (PFS) and overall survival (OS) were found to be significantly shorter by the Kaplan-Meier method in the high-VO group than in the low-VO group (PFS; P = 0.044, OS: P = 0.013). In addition, the higher percentage of visceral fat was correlated with more lymph node metastasis and shorter OS (P = 0.011 and P = 0.017, respectively). In patients with pancreatic cancer, VO at the time of diagnosis is associated with negative outcomes, such as shorter PFS and OS.

Obesity and male breast cancer: provocative parallels?

While rare compared to female breast cancer the incidence of male breast cancer (MBC) has increased in the last few decades. Without comprehensive epidemiological studies, the explanation for the increased incidence of MBC can only be speculated. Nevertheless, one of the most worrying global public health issues is the exponential rise in the number of overweight and obese people, especially in the developed world. Although obesity is not considered an established risk factor for MBC, studies have shown increased incidence among obese individuals. With this observation in mind, this article highlights the correlation between the increased incidence of MBC and the current trends in obesity as a growing problem in the 21(st) century, including how this may impact treatment. With MBC becoming more prominent we put forward the notion that, not only is obesity a risk factor for MBC, but that increasing obesity trends are a contributing factor to its increased incidence.

Complementary and Alternative Medicine Use Among Overweight and Obese Cancer Survivors in the United States

PURPOSE

The purpose of the study was to determine the prevalence of complementary and alternative medicine (CAM) use among US cancer survivors; examine whether use varies by underweight/normal weight, overweight, and obese body mass index status; determine reasons for use; and document disclosure rates of CAM use to medical professionals.

METHODS

Data for 1785 cancer survivors were obtained from the 2007 National Health Interview Survey and CAM supplement. The prevalence and associations of CAM use in the previous 12 months were compared among underweight/normal weight, overweight, and obese adult cancer survivors.

RESULTS

Nearly 90% of cancer survivors used at least one type of CAM therapy in the 12 months preceding the survey. Those who were overweight, but not obese, were more likely to use a CAM modality compared to normal/underweight respondents. Over two thirds (71%) reported using CAM therapy for general health and wellness and 39.3% used CAM because a health care provider recommended it. Disclosure rates of CAM use to conventional medical professionals varied widely by CAM modality.

CONCLUSIONS

An overwhelming majority of US cancer survivors use CAM for a variety of reasons. Overweight cancer survivors may be more likely to use CAM than those who are underweight, normal weight, or obese. Cancer survivors should be screened by medical providers for the use of CAM therapies; furthermore, prospective clinical research evaluating the efficacy and safety of biologically based CAM therapies, often used by cancer survivors, is important and necessary for the well-being of this population.

Inverse association between visceral obesity and lymph node metastasis in gastric cancer

BACKGROUND

The relationship between fat distribution and lymph node metastasis has not been well studied. The goal of this study was to determine the impact of visceral obesity on lymph node metastasis in gastric cancer.

MATERIALS AND METHODS

Metastatic lymph node ratio (MLR) was defined as the number of involved nodes by tumor divided by the total number of resected lymph nodes. Visceral (VFA) and subcutaneous fat areas (SFA) were determined by measuring abdominal fat volume distribution via CT scan, and visceral obesity was defined as a VFA to total fat area ratio (V/T) >0.29.

RESULTS

With lymph node metastasis as a dependent variable, the following factors were significant in multivariate analysis among 495 patients: pathologic T stage (P < 0.001), lympho-vascular invasion (P < 0.001), and V/T (hazard ratio (HR) = 0.455, 95 % confidence interval (CI) = 0.263-0.786, P = 0.005). Similarly, when MLR was the dependent variable in multivariate analysis, MLR was significantly associated with lympho-vascular invasion (HR = 2.222, 95 % CI = 1.149-4.296, P = 0.018), and V/T (HR = 0.247, 95 % CI = 0.133-0.458, P < 0.001).

CONCLUSIONS

Visceral obesity defined by higher visceral to total fat area ratio was significantly associated with decreased MLR.

The impact of a cancer diagnosis on weight change: findings from prospective, population-based cohorts in the UK and the US

Background

Obesity is a risk factor for cancer incidence and survival, but data on patterns of weight change in cancer survivors are scarce and few stratify by pre-diagnosis weight status. In two population-based cohorts of older adults, we examined weight change in cancer survivors and cancer-free controls in relation to baseline weight status.

Methods

In the English Longitudinal Study of Ageing (ELSA) and the Health and Retirement Study (HRS), we identified participants diagnosed with cancer who had pre- and post-diagnosis BMI data (ELSA n = 264; HRS n = 2553), and cancer-free controls (ELSA n = 1538; HRS n = 4946). Repeated-measures ANOVAs tested three-way interactions by group (cancer/control), time (pre-/post-diagnosis), and pre-diagnosis weight status (normal-weight/overweight/obese).

Results

Mean BMI change was -0.07 (SD = 2.22) in cancer survivors vs. +0.14 (SD = 1.11) in cancer-free controls in ELSA, and -0.20 (SD = 2.84) vs. +0.11 (SD = 0.93) respectively in HRS. Three-way interactions were significant in both cohorts (ELSA p = .015; HRS p < .001). In ELSA, mean BMI change in normal-weight cancer survivors was +0.19 (SD = 1.53) compared with -0.33 (SD = 3.04) in obese survivors. In ELSA controls, the respective figures were +0.09 (SD = 0.81) and +0.16 (SD = 1.50). In HRS, mean change in normal-weight cancer survivors was +0.07 (SD = 2.30) compared with -0.72 (SD = 3.53) in obese survivors. In HRS controls, the respective figures were +0.003 (SD = 0.66) and +0.27 (SD = 1.27).

Conclusion

Over a four-year period, in two cohorts of older adults, cancer survivors lost weight relative to cancer-free controls. However, cancer survivors who were obese pre-diagnosis were more likely to lose weight than healthy-weight survivors or obese adults without a cancer diagnosis. Whether this was due to differences in clinical status or deliberate lifestyle change triggered by the cancer diagnosis is not known. Further research is needed to establish why weight loss occurs more frequently in cancer survivors who were obese at diagnosis, and whether this has favourable effects on mortality.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-926) contains supplementary material, which is available to authorized users.

Obesity is a significant risk factor for breast cancer in Arab women

Background

Breast cancer (BC) is the most common malignancy and the leading cause of cancer-related death amongst women worldwide. The risk factors of this disease are numerous, and their prevalence varies between racial and ethnic groups as well as geographical regions. Therefore, we sought to delineate the association of socio-demographic, reproductive and life-style related risk factors with breast cancer in the Arab population.

Methods

Unmatched case-control study was conducted in the kingdom of Saudi Arabia using 534 cases of histologically confirmed breast cancer and 638 controls. Controls were randomly selected from primary health care visits and were free of breast cancer. Unconditional logistic regression analysis was performed to estimate odds ratios (ORs) and to examine the predictive effect of each factor on risk for BC. All study participants were interviewed by trained interviewers at hospital (cases) or at primary health care centers (controls).

Results

A total of 1172 women were eligible for this study, of which 281 (24.0%) were aged ≤35 years, 22.9% illiterate, 43.6% employed, 89.5% married, and 38.1% were obese. Grade III tumors constituted 38.4% of cases. Tumor stage I was 7.5%; II, 50.7%; II, 30.9%; IV, 11.1%. We have shown strong association between breast cancer among Arab females and obesity (OR =2.29, 95% CI 1.68-3.13), positive family history of breast cancer (OR =2.31, 95% CI 1.60 – 3.32), the use of hormonal replacement therapy (OR =2.25, 95% CI 1.65 – 3.08), post-menopause (OR =1.72, 95% CI 1.25 – 2.38), lack of education (OR =9.09, 95% CI 5.88 – 14.29), and never breastfeed (OR =1.89, 95% CI 1.19 – 2.94).

Conclusion

These results indicate the presence of classical risk factors established in the western countries, and also some specific ones, which may result from genetic and/or environmental factors. Thereby, these findings will be of great value to establish adequate evidence-based awareness and preventative measures in the Arab world.

The impact of overweight and obesity on breast cancer: data from Switzerland, so far a country little affected by the current global obesity epidemic

This review presents results from the project "The Impact of Overweight/Obesity on Breast Cancer: data from Switzerland". Swiss data is interesting because the general female population is distinctive in two areas when compared to that of most other industrialized countries: Switzerland has comparatively low rates of overweight (22-23%) and obesity (7-8%) and has rather stable rates of overweight and obesity. The entire project comprised three major issues: (I) etiology of breast cancer (BC). There is a consistently shown association between obesity and postmenopausal BC risk in countries with high obesity prevalence rates in the literature. In our Swiss study group, however, we did not find higher rates of overweight and obesity in postmenopausal BC cases than in the general population. A possible explanation for this observation may be a curvilinear dose-response relationship between BMI and postmenopausal BC risk, so that an increased risk may only be observed in populations with a high prevalence of obese/very obese women; (II) tumor characteristics. BMI was significantly associated with tumor size; this applied not only to the cases where the tumor was found by self-detection, but also to lesions detected by radiological breast examinations. In addition, a higher BMI was positively correlated with advanced TNM stage, unfavorable grading and a higher St. Gallen risk score. No associations were observed between BMI and histological subtype, estrogen receptor status, HER2 status and triple negative BC; (III) patient compliance and persistence towards adjuvant BC therapy. Many studies found that the prognosis of overweight/obese BC patients was significantly lower than that of normal weight patients. However, failure of compliance and persistence towards therapy on the part of the patient is not a contributing factor for this observed unfavorable prognosis. In most therapy modes, patients with increasing BMI demonstrated greater motivation and perseverance towards the recommended treatment.

Does BMI affect the accuracy of preoperative axillary ultrasound in breast cancer patients?

INTRODUCTION

Obesity affects 36 % of American women and is a well-documented breast cancer risk factor. Preoperative axillary ultrasound (AUS) is used routinely for axillary staging in newly diagnosed breast cancer patients; However, the impact of obesity on the usefulness of AUS is unknown. Our aim was to evaluate the effect of body mass index (BMI) on the performance of AUS.

METHODS

From our prospective breast surgery database, we identified 1,510 consecutive invasive breast cancers in patients undergoing primary surgery, including axillary operation, from January 2010 to July 2013. Preoperative AUS was performed in 1,375 cases (91 %). We analyzed patient, pathology and imaging data.

RESULTS

Median BMI was 27.4 and 479 patients (36 %) were classified as obese (BMI ≥ 30). Most tumors were T1 (71 %) and estrogen receptor-positive (87 %). AUS was suspicious in 401 (29 %) patients, of whom 374 had ultrasound-guided lymph node fine-needle aspiration (FNA). Overall, 124 patients (33.2 %) were FNA positive. FNA identified disease preoperatively in 35.8 % of node-positive obese patients. For all BMI categories (normal, overweight, obese), AUS was predictive of pathologic nodal status (p < 0.0001). AUS sensitivity did not differ across BMI categories, while specificity and accuracy were better for overweight (p = 0.001 and 0.008, respectively) and obese (p = 0.007 and 0.02, respectively) patients, than for normal-BMI patients.

CONCLUSIONS

Despite theoretical concern regarding both potential technical challenges and obesity-related lymph node alterations, the sensitivity of preoperative AUS for detecting nodal metastasis was similar in obese and non-obese patients, while specificity was better in obese patients. Preoperative AUS is valuable for preoperative nodal staging of obese breast cancer patients.

Impact of body mass index on prognostically relevant breast cancer tumor characteristics

BACKGROUND

This study analyzes the association of body mass index (BMI) and prognostically relevant breast cancer (BC) characteristics in a country that has been rather spared of the global obesity epidemic.

PATIENTS AND METHODS

Based on 20-year data (1999-2009, n = 1,414) of the prospective relational BC database of the University Hospital Basel, Switzerland, the associations between BMI, tumor size and stage, histological subtype, grading, hormonal receptor status, HER2 status and 'triple-negative' status were evaluated. Multivariate analysis considered BMI and patient's age.

RESULTS

The association between increasing BMI and the above-mentioned variables were as follows (results described in each case: Beta-coefficient or odds ratio, 95% confidence interval, p value): tumor size, (1) entire cohort: 0.03 (0.01-0.05), p < 0.001, (2) tumor found by self-palpation: 0.05 (0.03-0.07), p < 0.001, (3) tumor found by radiological examination: 0.03 (0-0.07), p = 0.044; advanced TNM stage: 1.16 (1.02-1.31), p = 0.022; histological subtype: 1.04 (0.89-1.22), p = 0.602; unfavorable grading: 1.11 (1.00-1.25), p = 0.057; positive estrogen receptor status: 0.95 (0.83-1.09), p = 0.459; positive HER2 status: 0.92 (0.74-1.15), p = 0.467; presence of a 'triple-negative' carcinoma: 1.19 (0.93-1.52), p = 0.165. Consideration of only postmenopausal BC patients (n = 1,063) did attenuate the results, but did not change the direction of the associations with BMI.

CONCLUSION

BMI was positively associated with TNM stage, grading and tumor size for tumors that were found by self-detection, as well as for those lesions detected by radiological breast examinations.

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.

Body fatness and breast cancer risk in women of African ancestry

Background

Obesity has been shown to be inversely associated with breast cancer risk in premenopausal women, while increasing risk in postmenopausal women. However, the current evidence is largely based on studies in Caucasian populations. Associations in women of African ancestry (AA), who have a higher prevalence of obesity, have been evaluated in few studies and results suggest different effects.

Methods

We evaluated the impact of body size, body fat distribution, and body composition on breast cancer risk among AA women (978 cases and 958 controls) participating in the Women’s Circle of Health Study, a multi-site case–control study in New York City (NYC) and New Jersey (NJ). Cases were newly diagnosed with histologically confirmed ductal carcinoma in situ or invasive breast cancer, age 20–75 yrs. In NYC, cases were recruited through hospitals with the largest referral patterns for AA women and controls through random digit dialing (RDD). In NJ, cases were identified in seven counties in NJ thorough the NJ State Cancer Registry, and controls through RDD and community-based recruitment. During in-person interviews, questionnaires were administered and detailed anthropometric measurements were obtained. Body composition was assessed by bioelectrical impedance analysis.

Results

BMI did not have a major impact on pre- or post-menopausal breast cancer, but was significantly associated with reduced risk of ER-/PR- tumors among postmenopausal women (OR: 0.37; 95% CI: 0.15-0.96 for BMI > 30 vs. BMI < 25). Furthermore, increased premenopausal breast cancer risk was found for higher waist and hip circumferences after adjusting for BMI, with ORs of 2.25 (95% CI: 1.07-4.74) and 2.91 (95% CI: 1.39-6.10), respectively, comparing the highest vs. lowest quartile. While ORs for higher fat mass and percent body fat among postmenopausal women were above one, confidence intervals included the null value.

Conclusions

Our study suggests that in AA women BMI is generally unrelated to breast cancer. However, higher waist and hip circumferences were associated with increased pre-menopausal breast cancer risk, while general obesity was associated with decreased risk of ER-/PR- tumors. Larger studies are needed to confirm findings and to evaluate the impact of obesity on breast cancer subtypes.

Differential gene expression in ERα-positive and ERα-negative breast cancer cells upon leptin stimulation

In postmenopausal women, adipositas represents a serious risk factor for cancer development and progression. White adipose tissue secretes the 16 kDa hormone leptin which plays a key role in the regulation of appetite and metabolism. An increasing number of reports indicate that leptin also interferes with signal transduction pathways implicated in the development of breast cancer. In our previous study, we identified the estrogen receptor alpha (ERα) as a relevant enhancer of leptin-induced signal transduction leading to transactivation of signal transducer and activator of transcription 3 (Stat3). The purpose of this study is the investigation of specific target gene expression in response to leptin-mediated Stat3 signaling. We performed a comprehensive microarray analysis of ERα-positive and ERα-negative MDA-MB-231 cells upon leptin treatment and identified 49 genes which showed a significant ERα-dependent regulation in leptin-treated MDA-MB-231 cells. There was no intersection with genes which were merely up- or downregulated by ERα expression and only 9 and 11 genes overlapping targets which were regulated by leptin stimulation either in ERα-expressing or ERα-negative MDA-MB-231 cells, respectively. To demonstrate the specificity, expression of three target genes was validated by quantitative real-time PCR. In conclusion, these data imply that leptin can induce a different set of target genes dependent on ERα expression, which might contribute to the development and progression of cancer diseases.

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.

Association of breast cancer and obesity in a homogeneous population from Spain

OBJECTIVE

To evaluate for the first time in Spain if the association between obesity and breast cancer prognosis is similar to that reported in other countries with non Mediterranean dietary patterns.

METHODS

Weight and height and other variables of interest, tumor characteristics and current clinical status 3 yr after diagnosis were retrieved from medical files of breast cancer women diagnosed during 2006. A total of 159 cases with complete information were studied and categorized according to the World Health Organization criteria in normal-/under-weight, overweight, and obese.

RESULTS

Among breast cancer patients, 70.4% were classified as overweight/ obese and 29.6% as normal weight. Prevalence of obesity was high (38.4%) in comparison with information reported for healthy women of the same region (27.11%) and was higher among post-menopausal patients and in women with low level of alcohol and tobacco consumption. Moreover, overweight/ obese cases (79.5%) tended to have more often human epidermal growth factor receptor 2 status negative when compared with those with normal weight (70.2%; p=0.097) and the survival curves tended to be influenced by body mass index although without statistical significance.

CONCLUSIONS

Overweight/obesity in a Mediterranean country is highly prevalent among breast cancer patients. Our results support a putative influence of obesity per se and not the alimentary patterns as a prognostic factor in breast cancer patients justifying the need to perform larger prospective studies.

The impact of obesity on breast cancer: a retrospective review

BACKGROUND

Obesity has been linked to many adverse health consequences, including breast cancer; however, the impact on clinical presentation, tumor characteristics, and survival outcomes has yet to be clearly defined.

METHODS

Retrospective review of a prospectively collected database of patients treated at a single institution for invasive breast cancer from 2000-2008 comparing two groups: nonobese (body mass index of <30) and obese (body mass index of ≥ 30) patients. Continuous variables, categorical variables, and survival data were analyzed.

RESULTS

Of 1352 total patients, 76% were classified as nonobese and 24% were obese. When comparing age, obese patients presented less frequently than nonobese patients <50 years old (10% vs. 90%), and when comparing patients >50 years old (18% vs. 82%, P = 0.0019). Obese patients were more likely to present with disease detected by imaging when compared to nonobese patients (67% vs. 56%, P = 0.0006). Obese patients had larger tumors (1.7 cm vs. 1.4 cm, P < 0.001) and higher rates of lymph node (LN) metastases (31% vs. 25%, P = 0.026). On multivariate analysis, obesity was associated with nonpalpable tumors, larger tumors, a higher incidence of LN metastasis, lower incidence of Her2 positivity, lower incidence of multifocality, and less likely to undergo reconstruction after mastectomy.

CONCLUSIONS

Obese patients clinically present at older ages with mammographically detected breast cancer at more advanced stages than nonobese patients. Strategies to encourage screening among the obese patient population are important.

Ethnic differences in survival after breast cancer in South East Asia

Background

The burden of breast cancer in Asia is escalating. We evaluated the impact of ethnicity on survival after breast cancer in the multi-ethnic region of South East Asia.

Methodology/Principal Findings

Using the Singapore-Malaysia hospital-based breast cancer registry, we analyzed the association between ethnicity and mortality following breast cancer in 5,264 patients diagnosed between 1990 and 2007 (Chinese: 71.6%, Malay: 18.4%, Indian: 10.0%). We compared survival rates between ethnic groups and calculated adjusted hazard ratios (HR) to estimate the independent effect of ethnicity on survival. Malays (n = 968) presented at a significantly younger age, with larger tumors, and at later stages than the Chinese and Indians. Malays were also more likely to have axillary lymph node metastasis at similar tumor sizes and to have hormone receptor negative and poorly differentiated tumors. Five year overall survival was highest in the Chinese women (75.8%; 95%CI: 74.4%–77.3%) followed by Indians (68.0%; 95%CI: 63.8%–72.2%), and Malays (58.5%; 95%CI: 55.2%–61.7%). Compared to the Chinese, Malay ethnicity was associated with significantly higher risk of all-cause mortality (HR: 1.34; 95%CI: 1.19–1.51), independent of age, stage, tumor characteristics and treatment. Indian ethnicity was not significantly associated with risk of mortality after breast cancer compared to the Chinese (HR: 1.14; 95%CI: 0.98–1.34).

Conclusion

In South East Asia, Malay ethnicity is independently associated with poorer survival after breast cancer. Research into underlying reasons, potentially including variations in tumor biology, psychosocial factors, treatment responsiveness and lifestyle after diagnosis, is warranted.

Obesity and breast cancer: a clinical biochemistry perspective

OBJECTIVES

To evaluate the laboratory diagnosis aspects of obesity-related health problems with special reference to postmenopausal breast cancer.

DESIGN AND METHODS

We conducted a systemic search of the literature primarily from the PubMed to obtain the relevant data.

RESULTS

Obesity is associated with the dysregulations of a number of body components such as blood constituents, extracellular matrix, and hormones/growth factors axes, which could be utilized for early diagnosis.

CONCLUSIONS

Obesity-related disorders including breast cancer have emerged as major health problems in almost all the nations. There is a need to elucidate different biochemical markers that are being used in the clinics or have the potential for such use. A precise understanding of the complex pathologies related with obesity is useful in prevention, early diagnosis and overall clinical management.

Impact of body mass index on compliance and persistence to adjuvant breast cancer therapy

Several authors found that the prognosis of overweight and obese breast cancer (BC) patients was lower than that of normal weight patients. We present the first study which evaluates the impact of body mass index (BMI) on compliance (i.e. to start a recommended therapy) and persistence to adjuvant BC therapy. An unselected cohort of 766 patients (≤75 years) diagnosed from 1997 to 2009 was analyzed in relevance to the four adjuvant therapy modalities: (A) radiation, (B) chemotherapy, (C) therapy with trastuzumab, and (D) endocrine therapy. With respect to compliance, multivariate analyses calculated Odds ratios (ORs) >1 for increased BMI in all four therapy modalities, i.e. increased BMI had a positive influence on compliance. The results were significant for radiotherapy (OR,2.37;95%CI,1.45-3.88;p < 0.001) and endocrine therapy (OR,1.92;95%CI,1.21-3.04;p = 0.002) and showed a trend in chemotherapy (OR,1.42;95%CI,0.97-2.08;p = 0.063). Analyzing persistence, increasing BMI had ORs <1 for chemotherapy and therapy with trastuzumab, both not reaching statistical significance. For endocrine therapy, increasing BMI was a significant predictor for persistence (OR,1.35;95%CI,1.08-1.80;p = 0.042). Failure of compliance and persistence to adjuvant therapy does not pose a contributing factor for the observed unfavorable prognosis in overweight/obese BC patients. In most therapy modes, patients with increasing BMI demonstrated a higher motivation and perseverance to the recommended treatment.

Bodyweight and other correlates of symptom-detected breast cancers in a population offered screening

OBJECTIVE

To determine the factors associated with symptom-detected breast cancers in a population offered screening.

METHODS

We interviewed 1,459 Australian women aged 40-69, 946 with symptom-detected and 513 with mammogram-detected invasive breast cancers ≥ 1.1 cm in diameter about their personal, mammogram, and breast histories before diagnosis and reviewed medical records for tumor characteristics and mammogram dates, calculating ORs and 95% confidence intervals (CIs) for symptom- versus mammogram-detected cancers in logistic regression models.

RESULTS

Lack of regular mammograms (<2 mammograms in the 4.5 years before diagnosis) was the strongest correlate of symptom-detected breast cancer (OR = 3.04 for irregular or no mammograms). In women who had regular mammograms (≥ 2 mammograms in the 4.5 years before diagnosis), the independent correlates of symptom-detected cancers were low BMI (OR < 25 kg/m(2) vs. ≥ 30 kg/m(2) = 2.18, 95% CI 1.23-3.84; p = 0.008), increased breast density (available in 498 women) (OR highest quarter vs. lowest = 3.50, 95% CI 1.76-6.97; p (trend) = 0.004), high-grade cancer, and a larger cancer (each p < 0.01). In women who did not have regular mammograms, the independent correlates were age <50 years, a first cancer, and a ≥ 2-cm cancer. Smoking appeared to modify the association of symptom-detected cancer with low BMI (higher ORs for low BMI in current smokers) and estrogen receptor (ER) status (higher ORs for low BMI in ER cancers).

CONCLUSION

Women with low BMI may benefit from a tailored approach to breast cancer detection, particularly if they smoke.

Paracrine-acting adiponectin promotes mammary epithelial differentiation and synergizes with genistein to enhance transcriptional response to estrogen receptor β signaling

Mammary stromal adipocytes constitute an active site for the synthesis of the adipokine, adiponectin (APN) that may influence the mammary epithelial microenvironment. The relationship between "local," mammary tissue-derived APN and breast cancer risk is poorly understood. Here, we identify a novel mechanism of APN-mediated signaling that influences mammary epithelial cell proliferation, differentiation, and apoptosis to modify breast cancer risk. We demonstrate that early dietary exposure to soy protein isolate induced mammary tissue APN production without corresponding effects on systemic APN levels. In estrogen receptor (ER)-negative MCF-10A cells, recombinant APN promoted lobuloalveolar differentiation by inhibiting oncogenic signal transducer and activator of transcription 3 activity. In ER-positive HC11 cells, recombinant APN increased ERβ expression, inhibited cell proliferation, and induced apoptosis. Using the estrogen-responsive 4X-estrogen response element promoter-reporter construct to assess ER transactivation and small interfering RNA targeting of ERα and ERβ, we show that APN synergized with the soy phytoestrogen genistein to promote ERβ signaling in the presence of estrogen (17β-estradiol) and ERβ-specific agonist 2,3-bis(4-hydroxyphenyl)-propionitrile and to oppose ERα signaling in the presence of the ERα-specific agonist 4,4',4'-(4-propyl-(1H)-pyrazole-1,3,5-triyl)trisphenol. The enhancement of ERβ signaling with APN + genistein cotreatments was associated with induction of apoptosis, increased expression of proapoptotic/prodifferentiation genes (Bad, p53, and Pten), and decreased antiapoptotic (Bcl2 and survivin) transcript levels. Our results suggest that mammary-derived APN can influence adjacent epithelial function by ER-dependent and ER-independent mechanisms that are consistent with reduction of breast cancer risk and suggest local APN induction by dietary factors as a targeted approach for promotion of breast health.

Impact of overweight and obesity on postmenopausal breast cancer: analysis of 20-year data from Switzerland

PURPOSE

Greater body fatness has been identified as a risk factor for postmenopausal breast cancer. For countries with low overweight/obesity rates, data on prevalence and time course of overweight/obesity in women with breast cancer in comparison to women in the general population is limited. The Swiss female population is distinctive for two reasons: (a) low rates of overweight/obesity compared with other western countries, and (b) no obesity epidemic, i.e. stable rates of overweight/obesity for more than 10 years.

METHODS

Overweight and obesity were analyzed in 51 to 80-year-old breast cancer patients initially diagnosed between 1990 and 2009. Patient data was derived from the Basel Breast Cancer Database (BBCD). This data was compared with the data of women of the same age from the four Swiss Health Surveys (SHS) conducted between 1992 and 2007. Differences between measured (BBCD) and self-reported (SHS) data were corrected using equations approved for the Swiss population.

RESULTS

Of 958 postmenopausal BBCD patients, 32% were overweight and 20% were obese. Of the 14,476 women of the SHS, 38% were overweight and 17% were obese. In the BBCD, there was no change in the prevalence of overweight/obesity over the last 20 years. The four SHS show a convex curvature for obesity, i.e. a transient increase. No significant differences were observed between BBCD and corrected SHS data for overweight and obesity during this period.

CONCLUSIONS

In this Swiss study group with a comparably low prevalence of overweight and obesity, no association between body fatness and postmenopausal breast cancer was observed.

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.

Biomarkers of the metabolic syndrome and breast cancer prognosis

In spite of its public health importance, our understanding of the mechanisms of breast carcinogenesis and progress is still evolving. The metabolic syndrome (MS) is a constellation of biochemical abnormalities including visceral adiposity, hyperglycemia, hyperinsulinemia, dyslipidemia and high blood pressure. The components of the MS have all been related to late-stage disease and even to a poor prognosis of breast cancer through multiple interacting mechanisms. In this review, we aim to present a summary of recent advances in the understanding of the contribution of the MS to breast cancer with the emphasis on the role of biomarkers of the MS in the prognosis of breast cancer.