The effect of body mass index on overall and disease-free survival in node-positive breast cancer patients treated with docetaxel and doxorubicin-containing adjuvant chemotherapy: the experience of the BIG 02-98 trial

Disease burden of breast cancer and risk factors in Europe 44 countries, 1990-2019: findings of the global burden of disease study 2019

Background

Breast cancer (BC) represents a significant health challenge in Europe due to its elevated prevalence and heterogeneity. Despite notable progress in diagnostic and treatment methods, the region continues to grapple with rising BC burdens, with comprehensive investigations into this matter notably lacking. This study explores BC burden and potential contributing risk factors in 44 European countries from 1990 to 2019. The aim is to furnish evidence supporting the development of strategies for managing BC effectively.

Methods

Disease burden estimates related to breast cancer from the Global Burden of Disease 2019(GBD2019) across Eastern, Central, and Western Europe were examined using Joinpoint regression for trends from 1990 to 2019. Linear regression models examined relationships between BC burden and Socio-demographic Index (SDI), healthcare access and quality (HAQ), and BC prevalence. We utilized disability-adjusted life year(DALY) proportions for each risk factor to depict BC risks.

Results

In Europe, the BC burden was 463.2 cases per 100,000 people in 2019, 1.7 times the global burden. BC burden in women was significantly higher and increased with age. Age-standardized mortality and DALY rates of BC in Europe in 2019 decreased by 23.1%(average annual percent change: AAPC -0.92) and 25.9%(AAPC -1.02), respectively, compared to 1990, in line with global trends. From 1990 to 2019, age-standardized DALY declined faster in Western Europe (-34.8%, AAPC -1.49) than in Eastern Europe (-9.4%, AAPC -0.25) and Central Europe (-15.0%, AAPC -0.56). Monaco, Serbia, and Montenegro had the highest BC burden in Europe in 2019. BC burden was negatively correlated with HAQ. In addition, Alcohol use and Tobacco were significant risk factors for DALY. High fasting plasma glucose and obesity were also crucial risk factors that cannot be ignored in DALY.

Conclusion

The burden of BC in Europe remains a significant health challenge, with regional variations despite an overall downward trend. Addressing the burden of BC in different regions of Europe and the increase of DALY caused by different risk factors, targeted prevention measures should be taken, especially the management of alcohol and tobacco should be strengthened, and screening services for BC should be popularized, and medical resources and technology allocation should be optimized.

Body mass index, weight change, and cancer prognosis: a meta-analysis and systematic review of 73 cohort studies

BACKGROUND

Identifying the association between body mass index (BMI) or weight change and cancer prognosis is essential for the development of effective cancer treatments. We aimed to assess the strength and validity of the evidence of the association between BMI or weight change and cancer prognosis by a systematic evaluation and meta-analysis of relevant cohort studies.

METHODS

We systematically searched the PubMed, Web of Science, EconLit, Embase, Food Sciences and Technology Abstracts, PsycINFO, and Cochrane databases for literature published up to July 2023. Inclusion criteria were cohort studies with BMI or weight change as an exposure factor, cancer as a diagnostic outcome, and data type as an unadjusted hazard ratio (HR) or headcount ratio. Random- or fixed-effects models were used to calculate the pooled HR along with the 95% confidence interval (CI).

RESULTS

Seventy-three cohort studies were included in the meta-analysis. Compared with normal weight, overweight or obesity was a risk factor for overall survival (OS) in patients with breast cancer (HR 1.37, 95% CI 1.22-1.53; P < 0.0001), while obesity was a protective factor for OS in patients with gastrointestinal tumors (HR 0.67, 95% CI 0.56-0.80; P < 0.0001) and lung cancer (HR 0.67, 95% CI 0.48-0.92; P = 0.01) compared with patients without obesity. Compared with normal weight, underweight was a risk factor for OS in patients with breast cancer (HR 1.15, 95% CI 0.98-1.35; P = 0.08), gastrointestinal tumors (HR 1.54, 95% CI 1.32-1.80; P < 0.0001), and lung cancer (HR 1.28, 95% CI 1.22-1.35; P < 0.0001). Compared with nonweight change, weight loss was a risk factor for OS in patients with gastrointestinal cancer.

CONCLUSIONS

Based on the results of the meta-analysis, we concluded that BMI, weight change, and tumor prognosis were significantly correlated. These findings may provide a more reliable argument for the development of more effective oncology treatment protocols.

Characterization of Physical Function and Cancer-Related Physical Impairments in Hispanic Women With Breast Cancer: A Descriptive Study

Introduction: This study reports characteristics of Hispanic women with breast cancer with respect to physical function, body mass index (BMI), and depression. Methods: This retrospective study included 322 Hispanic women with breast cancer. Physical function and fatigue were assessed using the Patient Reported Outcomes Measurement System-Physical Function (PROMIS-PF) short form and PROMIS-Fatigue (PROMISE-F) short form. In addition, Timed Up and Go (TUG) test, sit to stand in 30 s (STS30) test, four-stage balance test (4SB), and grip strength (GS) were measured. Depression was identified using Patient Health Questionnaire (PHQ)-2 and extracted from medical chart. Results: Nearly 40.8% were obese, and 20.8% had depression. Compared to normal BMI patients, mean PROMIS-F score was significantly higher among overweight and obese patients. The mean STS30 score was significantly lower in obese patients, compared to normal BMI patients. Regression analysis showed that the odds of depression were higher with increasing TUG and lower PROMIS-F, STS30, and GS. Conclusion: Hispanic women with breast cancer have substantial loss of physical function, and this is exaggerated if they are obese, overweight, or depressed. Clinicians caring for this population should screen them for the presence of loss of physical function, BMI, and depression.

Racial Disparity in Anthracycline-induced Cardiotoxicity in Breast Cancer Patients

Breast cancer has become the most common cancer in the US and worldwide. While advances in early detection and treatment have resulted in a 40% reduction in breast cancer mortality, this reduction has not been achieved uniformly among racial groups. A large percentage of non-metastatic breast cancer mortality is related to the cardiovascular effects of breast cancer therapies. These effects appear to be more prevalent among patients from historically marginalized racial/ethnic backgrounds, such as African American and Hispanic individuals. Anthracyclines, particularly doxorubicin and daunorubicin, are the first-line treatments for breast cancer patients. However, their use is limited by their dose-dependent and cumulative cardiotoxicity, manifested by cardiomyopathy, ischemic heart disease, arrhythmias, hypertension, thromboembolic disorders, and heart failure. Cardiotoxicity risk factors, such as genetic predisposition and preexisting obesity, diabetes, hypertension, and heart diseases, are more prevalent in racial/ethnic minorities and undoubtedly contribute to the risk. Yet, beyond these risk factors, racial/ethnic minorities also face unique challenges that contribute to disparities in the emerging field of cardio-oncology, including socioeconomic factors, food insecurity, and the inability to access healthcare providers, among others. The current review will address genetic, clinical, and social determinants that potentially contribute to this disparity.

Obesity and breast cancer prognosis: pre-diagnostic anthropometric measures in relation to patient, tumor, and treatment characteristics

PURPOSE

Examine the association between obesity and clinical outcomes in early breast cancer and assess if patient, tumor, and treatment characteristics modify such associations in Malmö Diet and Cancer Study patients (MDCS).

METHODS

The MDCS enrolled 17,035 Swedish women from 1991 to 1996. At enrollment, participants' body mass index (BMI), waist circumference and body fat percentage measures were collected. We identified all female MDCS participants with invasive breast cancer from 1991 to 2014. Follow-up began at breast cancer diagnosis and ended at breast cancer recurrence (BCR), death, emigration, or June 8, 2020. The World Health Organization guidelines were used to classify BMI, waist circumference, and body fat percentage into three categories of healthy weight, overweight, and obesity. We fit Cox regression models to compute adjusted hazard ratios (HRs) with 95% confidence intervals (CI) of BCR according to body composition. To evaluate effect measure modification, we stratified Cox models by patient, tumor, and treatment characteristics.

RESULTS

In total, 263 BCRs were diagnosed over 12,816 person-years among 1099 breast cancer patients with a median follow-up of 11.1 years. Obesity according to BMI (HR = 1.44 [95%CI 1.00-2.07]), waist circumference (HR = 1.31 [95%CI 0.98-1.77]), and body fat percentage (HR = 1.41 [95%CI 1.02-1.98]) was associated with increased risk of BCR compared with healthy weight. Obesity was stronger associated with BCR in patients with low socioeconomic position (HR = 2.55 [95%CI 1.08-6.02]), larger tumors > 20 mm (HR = 2.68 [95%CI 1.42-5.06]), estrogen-receptor-negative breast cancer (HR = 3.13 [95%CI 1.09-8.97]), and with adjuvant chemotherapy treatment (HR = 2.06 [95%CI 1.08-4.31]).

CONCLUSION

Higher pre-diagnostic BMI, waist circumference, and body fat percentage was associated with increased risk of BCR. The association between obesity and BCR appears dependent on patient, tumor, and treatment characteristics.

The relationship between women's body mass index and breast cancer outcomes was U-shaped

Background

Several studies have analyzed the relationship between body mass index (BMI) and the prognosis of breast cancer (BC). However, whether their relationship is linear or curvilinear remains unclear. This cohort study examined the specific relationship between BMI and BC outcomes.

Methods

This retrospective cohort study included 1049 BC patients from March 7, 2013 through December 31, 2019 in a hospital. Kaplan-Meier curves, multivariate Cox proportional models, and restricted cubic spline (RCS) was used to analysis the relationship between BMI and overall survival (OS) and breast cancer-specific survival (BCSS) was analyzed.

Results

During a median of 4.87 (IQR:3.26-6.84) years of follow-up period, 71 patients (6.77%) died, of which 50 (70.42%) were attributed to BC. RCS analysis revealed a U- shaped relationship between BMI levels and OS and BCSS after adjusting for other variables. The turning points of the U-shaped curves were 23 kg/m2. On the left side of the turning point, the risk of OS (HR, 0.83; 95% CI, 0.70, 0.98) and BCSS (HR, 0.80; 95% CI, 0.65, 0.98) were adversely correlated with BMI. In contrast, to the right of the turning point, the risk of OS (HR, 1.22; 95% CI, 1.10, 1.37) and BCSS (HR, 1.28; 95% CI, 1.13, 1.46) was positively related to BMI. Kaplan-Meier curves and multivariate Cox regression analyses shown consistent results with RCS analyses.

Conclusion

BMI was an independent prognostic factor for BC, and had a U-shaped relationship with OS and BCSS. Interventions should be designed to improve patient outcomes based on BMI.

Long-term atherosclerotic cardiovascular disease risk in patients with cancer: a population-based study

BACKGROUND

The long-term risk of incident atherosclerotic cardiovascular diseases (ASCVD) among cancer patients remains incompletely defined. This study aimed to evaluate the long-term ASCVD risk in cancer patients compared with the non-cancer population.

METHODS

This was a prospective population-based study using data from the Kailuan cohort, 6,204 individuals with newly diagnosed cancer, free of ASCVD, were matched in a 1:1 ratio to non-cancer controls for age (±1) and sex, from June 2006 to December 2020. Multivariable competing risk analyses were performed to evaluate the association between cancer diagnosis and risk of incident ASCVD events (including myocardial infarction, ischemic stroke, heart failure, and revascularization with coronary artery bypass graft surgery or percutaneous coronary intervention).

RESULTS

During a median follow-up of 5.3 (1.7, 9.7) years, 1,019 incident ASCVD events were observed. Compared to participants without cancer, there was a similar risk for incident ASCVD events among cancer patients within the first few years after cancer diagnosis, and the risk declined over time. Overall, cancer patients showed lower risks of incident ASCVD compared to the non-cancer patients over the long term, with a hazard ratio (95% confidence interval) of 0.52 (0.45-0.60) for composite ASCVD events, 0.43 (0.35-0.53) for ischemic stroke, 0.63 (0.42-0.95) for myocardial infarction, 0.63 (0.48-0.83) for heart failure, and 0.82 (0.60-1.11) for coronary revascularization. Baseline level of low-density lipoprotein cholesterol, fasting blood glucose, blood pressure, and high-sensitivity C-reactive protein could independently predict the incident ASCVD among the study population. Subgroup analyses according to cancer types revealed a significantly lower risk of ASCVD events among patients with digestive cancer or respiratory cancer compared with non-cancer controls, but not for urologic or genital cancer. Multiple sensitivity analyses yielded similar results to the primary analysis.

CONCLUSIONS

Long-term ASCVD risk among cancer survivors is not increased compared with the non-cancer individuals, probably driven by a favorable profile of baseline risk factor in cancer population.

Postdiagnosis body fatness, weight change and breast cancer prognosis: Global Cancer Update Program (CUP global) systematic literature review and meta-analysis

Previous evidence on postdiagnosis body fatness and mortality after breast cancer was graded as limited-suggestive. To evaluate the evidence on body mass index (BMI), waist circumference, waist-hip-ratio and weight change in relation to breast cancer prognosis, an updated systematic review was conducted. PubMed and Embase were searched for relevant studies published up to 31 October, 2021. Random-effects meta-analyses were conducted to estimate summary relative risks (RRs). The evidence was judged by an independent Expert Panel using pre-defined grading criteria. One randomized controlled trial and 225 observational studies were reviewed (220 publications). There was strong evidence (likelihood of causality: probable) that higher postdiagnosis BMI was associated with increased all-cause mortality (64 studies, 32 507 deaths), breast cancer-specific mortality (39 studies, 14 106 deaths) and second primary breast cancer (11 studies, 5248 events). The respective summary RRs and 95% confidence intervals per 5 kg/m2 BMI were 1.07 (1.05-1.10), 1.10 (1.06-1.14) and 1.14 (1.04-1.26), with high between-study heterogeneity (I2  = 56%, 60%, 66%), but generally consistent positive associations. Positive associations were also observed for waist circumference, waist-hip-ratio and all-cause and breast cancer-specific mortality. There was limited-suggestive evidence that postdiagnosis BMI was associated with higher risk of recurrence, nonbreast cancer deaths and cardiovascular deaths. The evidence for postdiagnosis (unexplained) weight or BMI change and all outcomes was graded as limited-no conclusion. The RCT showed potential beneficial effect of intentional weight loss on disease-free-survival, but more intervention trials and well-designed observational studies in diverse populations are needed to elucidate the impact of body composition and their changes on breast cancer outcomes.

Risk factors from Framingham risk score for anthracyclines cardiotoxicity in breast cancer: A systematic review and meta-analysis

Background

Framingham risk score (FRS) is an effective tool for evaluating the 10-year risk of cardiovascular diseases. However, the sensitivity of FRS for anthracycline-induced cardiotoxicity is unclear. This meta-analysis aims to evaluate the correlation between risk factors (hypertension, hyperlipidemia, diabetes, smoking, and obesity) in FRS and anthracycline-induced cardiotoxicity in breast cancer.

Methods

We searched PubMed, EMBASE, and Cochrane Library for studies published from inception to January 2022 which reported cardiotoxicity due to anthracycline. Cardiotoxicity defined as any cardiac events were used as the primary endpoint. A total of 33 studies involving 55,708 breast cancer patients treated with anthracyclines were included in this meta-analysis.

Results

At least one risk factor was identified at baseline for the 55,708 breast cancer patients treated with anthracycline. Hypertension [I ² = 45%, Fixed, RR (95% CI) = 1.40 (1.22, 1.60), p < 0.00001], hyperlipidemia [I ² = 0%, Fixed, RR (95% CI): 1.35 (1.12, 1.62), p = 0.002], diabetes [I ² = 0%, Fixed, RR (95% CI): 1.29 (1.05, 1.57), p = 0.01], and obesity [I ² = 0%, Fixed, RR (95% CI): 1.32 (1.05, 1.67), p = 0.02] were associated with increased risks of cardiac events. In addition, smoking was also associated with reduced left ventricular ejection fraction (LVEF) during anthracycline chemotherapy [I ² = 0%, Fixed, OR (95% CI): 1.91 (1.24, 2.95), p = 0.003] in studies that recorded only the odds ratio (OR).

Conclusion

Hypertension, hyperlipidemia, diabetes, smoking, and obesity are associated with increased risks of anthracycline-induced cardiotoxicity. Therefore, corresponding measures should be used to manage cardiovascular risk factors in breast cancer during and after anthracycline treatment.

Bilateral breast cancer and the influence of body mass index in clinicopathological features and overall survival

BACKGROUND

Breast cancer (BC) and obesity are two closely associated pathologies with increasing incidence and mortality rates. Bilateral Breast Cancer (BBC) displays a low incidence rate within BC and obesity represents a major risk factor.

OBJECTIVE

The aim of this study is to analyzed BBC clinicopathological features distribution and determine the potential influence of obesity in BBC in these same features and overall survival.

METHODS

Clinicopathological information was obtained from 42 cases of women with BBC diagnosed in IPO-Porto. To evaluate the frequency distribution of the clinicopathological data, a chi-square goodness of fit test was performed for BBC cases. A chi-square test of independence was applied for BMI stratification. Cox regression was performed for overall survival. Statistical significance was set at p-value < 0.05.

RESULTS

Distribution of BBC clinicopathological features was found to be statistically significant in family history (p-value < 0.001), BBC type (p-value < 0.001), stage (p-value = 0.005), differentiation grade (p-value < 0.001), receptor expression (p-value < 0.001) and histological type (p-value = 0.031). In comparison to the statistical expected results, we observed an increased cases of absence of family history and less cases of metachronous BBC. Histological types between tumours of BBC were mostly concordant. All cases presented concordant receptor expression. Analysis stratified by BMI revealed that obese women were diagnosed later, although without statistical significance. All obese women presented poor differentiation grade (n = 6). Overweight patients display a tendency to a better overall survival with lower tumour stages and lower differentiation grades.

CONCLUSIONS

Our results reveal the same receptor expression between contralateral tumours. Also, most tumours share the same histological type. When stratified by BMI, we observed a tendency for overweight women to have improved overall survival.

Cellular reprogramming, chemoresistance, and dietary interventions in breast cancer

Breast cancer (BC) diagnosis has been associated with significant risk factors, including family history, late menopause, obesity, poor eating habits, and alcoholism. Despite the advances in the last decades regarding cancer treatment, some obstacles still hinder the effectiveness of therapy. For example, chemotherapy resistance is common in locally advanced or metastatic cancer, reducing treatment options and contributing to mortality. In this review, we provide an overview of BC metabolic changes, including the impact of restrictive diets associated with chemoresistance, the therapeutic potential of the diet on tumor progression, pathways related to metabolic health in oncology, and perspectives on the future in the area of oncological nutrition.

Cytokines secreted from adipose tissues mediate tumor proliferation and metastasis in triple negative breast cancer

Background

Obesity is a high-risk factor for development and poor prognosis of triple-negative breast cancer (TNBC), which was considered as a high malignant and poor clinical outcome breast cancer subtype. TNBC proliferation and migration regulated by obesity is complex. Here, we studied effects of cytokines secreted from adipose tissue on development of TNBC.

Methods

Forty postmenopausal cases by Yuebei People’s Hospital of Shaoguan with stage I/IIA TNBC were enrolled. Cytokine concentrations were examined using ELISA analysis. Proliferation and migration of TNBC cell lines were performed using CCK8 assays and Transwell tests. The Log-rank (Mantel-Cox) test, two-tailed Mann-Whitney U test and two-tailed unpaired t test were performed using GraphPad Prism 8.4.2.

Results

Survival analysis indicated that obese patients with TNBC had worse disease free survival (DFS) as compared with normal weight group (Hazard Ratio 4.393, 95% confidence interval (CI) of ratio 1.071–18.02, p < 0.05). Obese patients with TNBC had severe insulin resistance and high plasma triglycerides. However, plasma adiponectin concentration was decreased and interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) concentration was increased in obese TNBC patients as compared with the nonobese group. The similar results were found in the cytokine secretion from adipose tissues and insulin-resistant adipocytes. The secretion of adipose tissue from obese TNBC patients could promote proliferation and migration of TNBC cell lines, including MDA-MB-157, MDA-MB-231, MDA-MB-453 and HCC38 cells. These TNBC cell lines co-incubated with insulin-resistant 3T3-L1 adipocytes or supplementing these cytokines medium also exhibited increase of proliferative and migratory capacity.

Conclusion

TNBC patients with obesity had worse prognosis compared with the normal weight groups. Alteration of cytokines secreted from adipose tissues mediated proliferation and migration of TNBC, leading to tumor progression in TNBC patients with obesity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09959-6.

Body mass index increases the recurrence risk of breast cancer: a dose-response meta-analysis from 21 prospective cohort studies

OBJECTIVE

The purpose of this study was to investigate the effect of body mass index (BMI) on the recurrence risk of breast cancer.

STUDY DESIGN

Dose-response meta-analysis.

METHODS

Cohort studies that included BMI and the recurrence of breast cancer were selected through various databases including PubMed, Web of Science, the China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals (VIP), and Wanfang Data Knowledge Service Platform (WanFang) until November 30, 2021. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of literature. A two-stage random-effects meta-analysis was performed to assess the dose-response relationship between BMI and breast cancer recurrence risk. Heterogeneity between studies is assessed using I².

RESULTS

The relative risk (RR) of BMI <25 kg/m² vs BMI ≥25 kg/m², BMI <30 kg/m² vs BMI ≥30 kg/m² were 1.09 (95% CI: 1.00-1.19) and 1.15 (95% CI: 1.04-1.27), suggesting that BMI had a significant effect on the recurrence risk of breast cancer, and there might be a dose-response relationship between them. A total of 21 studies were included in dose-response meta-analysis, which showed that there was a positive linear correlation between BMI and the risk of recurrence (RR = 1.02, 95% CI: 1.01-1.03). For every 1 kg/m² increment of BMI, the risk of recurrence increased by approximately 2%. In subgroup analyses, positive linear dose-response relationships between BMI and recurrence risk were observed among Asian and study period >10 years groups. For every 1 kg/m² increment of BMI, the risk of recurrence increased by 3.41% and 1.87%, respectively.

CONCLUSIONS

The recurrence risk of breast cancer increases with BMI, which is most obvious among Asian women.

Association of Obesity and Luminal Subtypes in Prognosis and Adjuvant Endocrine Treatment Effectiveness Prediction in Chinese Breast Cancer Patients

Purpose

To evaluate the influence of obesity on clinicopathological characteristics of breast cancer; to explore the effect of obesity on the prognosis and performance of endocrine therapy in breast cancer patients.

Methods

Patients with luminal/HER2-negative early breast cancer were included and categorized into the non-obese (BMI<28kg/m²) and obese (BMI≥28kg/m²) groups according to body mass index (BMI). Clinicopathological characteristics and treatment modalities were compared between groups. Interaction of adjuvant endocrine therapy with obesity was analyzed.

Results

A total of 2,875 patients were included: 2,598 non-obese and 277 obese. A higher rate of patients with comorbidities (OR: 2.83, 95%CI 2.13-3.74, P<0.001) or PR-positive tumor (OR: 1.63, 95%CI 1.03-2.58, P=0.037) were identified in the obese group. Obesity was not associated with disease recurrence (P=0.839) or overall survival (P=0.140) in the whole population. Subgroup analysis did show an association with worse relapse-free survival (RFS, HR 3.48, 95%CI 1.31-9.22, P=0.012) and overall survival (OS, HR 4.67, 95%CI 1.28-16.95, P=0.019) in luminal A breast cancer. These results could not be reproduced in the luminal B subtype with a RFS (HR 0.78, 95%CI 0.41-1.49, P=0.454) or OS (HR 1.17, 95%CI 0.50-2.74, P=0.727). Furthermore, obesity did not impact endocrine therapy effectiveness in Tamoxifen or the aromatase inhibitor group (RFS: interact P=0.381; OS: interact P=0.888).

Conclusions

The impact of obesity on prognosis interacted with luminal subtype status in Chinese breast cancer patients which was not related with endocrine treatment modality.

Lifestyle and Socioeconomic Transition and Health Consequences of Breast Cancer in the East Asia Region, From 1990 to 2019

Background

Due to its higher prevalence and heterogeneity, female breast cancer (BC) is the widest disease throughout the world. We sought to assess the epidemiological and sociodemographic transitions of BC and to identify the potential risk factors attributed to burden of BC in East Asia.

Methods

At the regional level of East Asia and at a national level of East Asian countries, we investigated the burden of the incidence of female BC, mortality, and disability-adjusted life years (DALYs) in 2019 and assessed the epidemiological, socioeconomic, and health-linked disparities in incidence of BC and mortality over a 30-year period. The changes in BC’s mortality and DALYs between 1990 and 2019, attributable to varying risk factors, were evaluated in different age groups.

Results

In 2019, the incidence of and mortality from and DALYs of BC were estimated to be 382,321 (95% UI: 303,308–477,173) incidence cases [age-standardized rate (ASR) of 35.69 per 100,000; 28.32–44.54], 98,162 (79,216–120,112) deaths (ASR of 9.12; 7.36–11.13), and 3,024,987 (2,477, 984–3,659,370) DALYs with an ASR of 282.15 (230.81–341.19) in 2019. It was also observed that out of four most representative locations of East Asia, two (China and Japan) showed more than 60% increase in age-standardized incidence rate between 1990 and 2019. While only Japan females showed a significant rise of 15.3% (95% UI: 2.3–28) in ASR of death and 12.6% (95% UI: 0.5–26.9) in ASR of DALYs between 1990 and 2019. Inclusively, 88 and 81% variations were explained in the incidence of BC and death due to change in sociodemographic index (SDI) in 2019, in East Asia. The highest positive percent changes in death and DALYs between 1990 and 2019 were attributable to high body mass index (BMI), high fasting plasma glucose (FPG), and alcohol consumption in East Asia.

Conclusion

The burden of death and disability from female BC is the result of multiple risk factors, mainly due to behavioral and metabolic risk factors. The increase of the incidence is related to the westernized lifestyle and diet habits and the improvement of screening and diagnosis techniques in the recent years, whereas the increase in DALYs is mainly attributed to high BMI, high FPG, alcohol use, and high diet in red meat.

Differential effect of body mass index (BMI) on outcomes of patients treated with docetaxel in prostate cancer - An exploratory analysis

OBJECTIVE

There are contradictory data on differential effect of docetaxel based on BMI in patients with breast and prostate cancer. We performed an exploratory analysis to determine if the benefit of docetaxel in patients with metastatic castration-resistant prostate cancer (mCRPC) is modified by BMI.

METHODS

We performed a post hoc analysis of the data retrieved from the ENTHUSE M1C study. BMI (kg/m²) was categorized as: 18.5 to <25 as lean; 25 to <30 as overweight; and ≥30 as obese. Cox regression models were constructed to determine the impact of BMI on progression-free survival (PFS) and overall survival (OS).

RESULTS

A total of 466 patients were eligible for the current analysis. The median PFS was 7.3, 7.7 and 8.4 months (hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.81 to 1.06; P = 0.261) in lean, overweight and obese patients. The median OS was 16.6, 20.1 and 21.4 months (HR, 0.75; 95% CI, 0.63 to 0.89; P = 0.002) for lean, overweight and obese patients. After adjusting for baseline and tumor characteristics, there was no association of BMI with PFS (overweight, HR, 0.89; 95% CI, 0.71 to 1.13; P = 0.353; obese, HR, 0.86; 95% CI, 0.66 to 1.13; P = 0.277) while overweight (HR, 0.68; 95% CI, 0.51 to 0.89; P = 0.006) and obese (HR, 0.59; 95% CI, 0.41 to 0.83; P = 0.003) patients had significantly better OS compared with lean patients.

CONCLUSIONS

There was no effect of BMI on PFS in patients with mCRPC receiving docetaxel. Interestingly, overweight and obese patients had a longer OS compared with lean patients, which is in contradiction to a recent study in breast cancer; and warrants further investigation.

Clinical Implications of Body Mass Index in Metastatic Breast Cancer Patients Treated With Abemaciclib and Endocrine Therapy

BACKGROUND

There are limited data regarding the impact of body mass index (BMI) on outcomes in advanced breast cancer, especially in patients treated with endocrine therapy (ET) + cyclin-dependent kinase 4/6 inhibitors.

METHODS

A pooled analysis of individual patient-level data from MONARCH 2 and 3 trials was performed. Patients were classified according to baseline BMI into underweight (<18.5 kg/m2), normal (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2), and obese (≥30 kg/m2) and divided into 2 treatment groups: abemaciclib + ET vs placebo + ET. The primary endpoint was progression-free survival (PFS) according to BMI in each treatment group. Secondary endpoints were response rate, adverse events according to BMI, and loss of weight (≥5% from baseline) during treatment.

RESULTS

This analysis included 1138 patients (757 received abemaciclib + ET and 381 placebo + ET). There was no difference in PFS between BMI categories in either group, although normal-weight patients presented a numerically higher benefit with abemaciclib + ET (Pinteraction = .07). Normal and/or underweight patients presented higher overall response rate in the abemaciclib + ET group compared with overweight and/or obese patients (49.4% vs 41.6%, odds ratio = 0.73, 95% confidence interval = 0.54 to 0.99) as well as higher neutropenia frequency (51.0% vs 40.4%, P = .004). Weight loss was more frequent in the abemaciclib + ET group (odds ratio = 3.23, 95% confidence interval = 2.09 to 5.01).

CONCLUSIONS

Adding abemaciclib to ET prolongs PFS regardless of BMI, showing that overweight or obese patients also benefit from this regimen. Our results elicit the possibility of a better effect of abemaciclib in normal and/or underweight patients compared with overweight and/or obese patients. More studies analyzing body composition parameters in patients under treatment with cyclin-dependent kinase 4/6 inhibitors may further clarify this hypothesis.

Pre-treatment high body mass index is associated with poor survival in Asian premenopausal women with localized breast cancer

Background: Obesity is associated with poor prognosis in breast cancer patients. This study aimed to evaluate the effect of obesity measured by body mass index (BMI) on survival of Taiwanese breast cancer patients in a single institution.

Methods: We observed 5000 patients who were diagnosed with stage I-III breast cancer between 1990 and 2005. Information on BMI at diagnosis, and clinical follow-up for disease recurrence and death, up to 20 years post-diagnosis were available. BMI (in kg/m²) categories included normal weight (BMI<24), overweight (24≤BMI<27), and obesity (BMI≥27), according to recommendations from the Bureau of Health Promotion of Taiwan. The role of BMI and other known prognostic factors for patient survival were evaluated in this patient cohort.

Results: Obesity was associated with advanced stage, higher nuclear grade, and higher percentages of estrogen receptor (ER) positive. The median age of patients with a higher BMI was greater than the median age of patients with a lower BMI. Obesity was an independent prognostic factor of overall survival (OS) (P<0.001), but not disease-free survival (DFS) (P=0.067). We subsequently analyzed the impact of age-stratified BMI (age<50 and age≥50 years) to ameliorate the impact of age bias. Following subset analyses, obesity correlated with shorter DFS (P=0.004) and OS (P=0.009) only in women<50 years of age. Multivariate analysis revealed that BMI was an independent prognostic factor for both DFS and OS in this group of patients. Subset analysis revealed that in women <50 years old, the impact of BMI on survival was associated with higher stage, ER negativity.

Conclusion: BMI is an independent prognostic factor of OS and DFS in breast cancer patients aged<50 years. Although the cause-effect relationship between obesity and survival is unclear, we recommend that weight control measures in young breast cancer survivors should be considered.

Influence of Height on Risk and Outcome of Patients with Early Breast Cancer: A Pooled Analysis of 4,925 Patients from 5 Randomized Trials of the Austrian Breast and Colorectal Cancer Study Group (ABCSG)

<b><i>Background:</i></b> Associations between height, cancer risk and worse outcome have been reported for several cancers including breast cancer. We hypothesized that in breast cancer clinical trials, tall women should be overrepresented and might have worse prognosis. <b><i>Methods:</i></b> Data of 4,935 women, included from 1990 to 2010 in 5 trials of the Austrian Breast and Colorectal Cancer Study Group (ABCSG), were analyzed retrospectively. The primary objective was to determine differences in height distribution between the ABCSG cohort and the Austrian female population according to a cross-sectional health survey conducted by the Austrian Statistic Center in 2006 and 2007. Secondary endpoints were disease-free survival (DFS) and overall survival (OS) in different height classes and differences of body mass index (BMI) distribution. <b><i>Results:</i></b> Breast cancer patients in the ABCSG cohort were only slightly but statistically significantly smaller compared to unselected Austrian adult females (mean 164.3 vs. 164.8 cm; <i>p</i> &#x3c; 0.0001) and significantly more patients were seen in the lower body height class (50 vs. 46%; <i>p</i> &#x3c; 0.0001) when using the median as a cutoff. However, after adjustment for age, the difference in body height between the two cohorts was no longer significant (<i>p</i> = 0.089). DFS and OS in the two upper height groups (≥170 cm) compared to the two lowest height groups (&#x3c;160 cm) was not significantly different (5-year DFS: 84.7 vs. 83.0%; HR 0.91, 95% CI 0.73–1.13, <i>p</i> = 0.379; 5-year OS: 94.8 vs. 91.7%; HR 0.74, 95% CI 0.55–1.00, <i>p</i> = 0.051). The BMI of ABCSG patients was significantly higher than in the reference population (mean BMI 24.64 vs. 23.96; <i>p</i> &#x3c; 0.0001). <b><i>Conclusions:</i></b> Our results do not confirm previous findings that greater body height is associated with a higher breast cancer risk and worse outcome.

Crown-Like Structures in Breast Adipose Tissue: Early Evidence and Current Issues in Breast Cancer

Simple Summary

Obesity increases the risk of postmenopausal, hormone receptor-positive breast cancer and has been linked to a higher risk of recurrence and mortality. During obesity, adipose tissue can become dysfunctional, resulting in chronic low-grade inflammation. Crown-like structures in breast adipose tissue (CLS-B), composed of macrophages surrounding dead or dying adipocytes in a crown-like pattern, are a new histologic marker of local inflammation. In this review, we aim to evaluate the early evidence of CLS-B in breast cancer. There is consistent evidence that CLS-B are more frequently detected among obese compared to non-obese breast cancer patients. Additionally, several studies have found that CLS-B presence is associated with metabolic and inflammatory factors that contribute to breast cancer development and progression. However, more studies are needed to understand the potential clinical utility of CLS-B as a marker of breast cancer risk or prognosis.

Abstract

Obesity is an established risk factor for postmenopausal breast cancer and has been linked to worse breast cancer prognosis, most clearly for hormone receptor-positive breast cancers. The underlying mechanisms of the obesity–breast cancer association are not fully understood, but growing evidence points to the breast adipose tissue microenvironment playing an important role. Obesity-induced adipose tissue dysfunction can result in a chronic state of low-grade inflammation. Crown-like structures of the breast (CLS-B) were recently identified as a histologic marker of local inflammation. In this review, we evaluate the early evidence of CLS-B in breast cancer. Data from preclinical and clinical studies show that these inflammatory lesions within the breast are associated with local NF-κB activation, increased aromatase activity, and elevation of pro-inflammatory mediators (TNFα, IL-1β, IL-6, and COX-2-derived PGE₂)—factors involved in multiple pathways of breast cancer development and progression. There is also substantial evidence from epidemiologic studies that CLS-B are associated with greater adiposity among breast cancer patients. However, there is insufficient evidence that CLS-B impact breast cancer risk or prognosis. Comparisons across studies of prognosis were complicated by differences in CLS-B evaluation and deficiencies in study design, which future studies should take into consideration. Breast adipose tissue inflammation provides a plausible explanation for the obesity–breast cancer association, but further study is needed to establish its role and whether markers such as CLS-B are clinically useful.

Race, ethnicity and risk of second primary contralateral breast cancer in the United States

Breast cancer survivors have a high risk of a second primary contralateral breast cancer (CBC), but there are few studies of CBC risk in racial/ethnic minority populations. We examined whether the incidence and risk factors for CBC differed by race/ethnicity in the United States. Women with a first invasive Stage I-IIB breast cancer diagnosis at ages 20-74 years between 2000 and 2015 in the Surveillance, Epidemiology, and End Results Program (SEER) 18 registries were followed through 2016 for a diagnosis of invasive CBC ≥1 year after the first breast cancer diagnosis. We used cause-specific Cox proportional hazards models to test the association between race/ethnicity and CBC, adjusting for age, hormone receptor status, radiation therapy, chemotherapy and stage at first diagnosis, and evaluated the impact of contralateral prophylactic mastectomy, socioeconomic status, and insurance status on the association. After a median follow-up of 5.9 years, 9247 women (2.0%) were diagnosed with CBC. Relative to non-Hispanic (NH) White women, CBC risk was increased in NH Black women (hazard ratio = 1.44, 95% CI 1.35-1.54) and Hispanic women (1.11, 95% CI 1.02-1.20), with the largest differences among women diagnosed at younger ages. Adjustment for contralateral prophylactic mastectomy, socioeconomic status and health insurance did not explain the associations. Therefore, non-Hispanic Black and Hispanic women have an increased risk of CBC that is not explained by clinical or socioeconomic factors collected in SEER. Large studies of diverse breast cancer survivors with detailed data on treatment delivery and adherence are needed to inform interventions to reduce this disparity.

Optimising weight-loss interventions in cancer patients-A systematic review and network meta-analysis

Background

Excess weight has been associated with increased morbidity and a worse prognosis in adult patients with early-stage cancer. The optimal lifestyle interventions to optimize anthropometric measures amongst cancer patients and survivors remain inconsistent.

Objective

To conduct a systematic review and network meta-analysis (NMA) of randomized controlled trials (RCTs) comparing the effects of exercise and dietary interventions alone or in combination on anthropometric measures of adult cancer patients and survivors.

Methods

A systematic search of Medline, Embase and the Cochrane Trials Registry was performed. Outcomes of interest included changes in weight, body mass index (BMI), and waist circumference. Screening and data collection were performed by two reviewers. Bayesian NMAs were performed.

Results

Overall, 98 RCTs were included; 75 were incorporated in NMAs (n = 12,199). Groups of intervention strategies included: 3 exercise interventions, 8 dietary interventions, 7 combination interventions of diet and exercise and standard care. Median intervention duration was 26 weeks. NMA suggested that diet alone (mean difference [MD] -2.25kg, 95% CrI -3.43 to -0.91kg) and combination strategies (MD -2.52kg, 95% CrI -3.54 to -1.62kg) were associated with more weight loss compared to standard care. All dietary interventions achieved a similar magnitude of weight loss (MD range from -2.03kg to -2.52kg). Both diet alone and combination strategies demonstrated greater BMI reductions versus standard care, and each of diet alone, exercise alone and combination strategies demonstrated greater reductions in waist circumference than standard care.

Conclusion

Diet and exercise alone or in combination are effective lifestyle interventions to improve anthropometric measures in cancer patients and survivors. All reputable diets appear to be similarly effective to achieve weight loss.

Obesity and Cancer Metastasis: Molecular and Translational Perspectives

Obesity is a modern health problem that has reached pandemic proportions. It is an established risk factor for carcinogenesis, however, evidence for the contribution of adipose tissue to the metastatic behavior of tumors is also mounting. Over 90% of cancer mortality is attributed to metastasis and metastatic tumor cells must communicate with their microenvironment for survival. Many of the characteristics observed in obese adipose tissue strongly mirror the tumor microenvironment. Thus in the case of prostate, pancreatic and breast cancer and esophageal adenocarcinoma, which are all located in close anatomical proximity to an adipose tissue depot, the adjacent fat provides an ideal microenvironment to enhance tumor growth, progression and metastasis. Adipocytes provide adipokines, fatty acids and other soluble factors to tumor cells whilst immune cells infiltrate the tumor microenvironment. In addition, there are emerging studies on the role of the extracellular vesicles secreted from adipose tissue, and the extracellular matrix itself, as drivers of obesity-induced metastasis. In the present review, we discuss the major mechanisms responsible for the obesity-metastatic link. Furthermore, understanding these complex mechanisms will provide novel therapies to halt the tumor-adipose tissue crosstalk with the ultimate aim of inhibiting tumor progression and metastatic growth.

Is there scope for better individualisation of anthracycline cancer chemotherapy?

Anthracyclines are used to treat solid and haematological cancers, particularly breast cancers, lymphomas and childhood cancers. Myelosuppression and cardiotoxicity are the primary toxicities that limit treatment duration and/or intensity. Cardiotoxicity, particularly heart failure, is a leading cause of morbidity and mortality in cancer survivors. Cumulative anthracycline dose is a significant predictor of cardiotoxicity risk, suggesting a role for anthracycline pharmacokinetic variability. Population pharmacokinetic modelling in children has shown that doxorubicin clearance in the very young is significantly lower than in older children, potentially contributing to their higher risk of cardiotoxicity. A model of doxorubicin clearance based on body surface area and age offers a patient-centred dose-adjustment strategy that may replace the current disparate initial-dose selection tools, providing a rational way to compensate for pharmacokinetic variability in children aged <7 years. Population pharmacokinetic models in adults have not adequately addressed older ages, obesity, hepatic and renal dysfunction, and potential drug-drug interactions to enable clinical application. Although candidate gene and genome-wide association studies have investigated relationships between genetic variability and anthracycline pharmacokinetics or clinical outcomes, there have been few clinically significant reproducible associations. Precision-dosing of anthracyclines is currently hindered by lack of clinically useful pharmacokinetic targets and models that predict cumulative anthracycline exposures. Combined with known risk factors for cardiotoxicity, the use of advanced echocardiography and biomarkers, future validated pharmacokinetic targets and predictive models could facilitate anthracycline precision dosing that truly maximises efficacy and provides individualised early intervention with cardioprotective therapies in patients at risk of cardiotoxicity.

Redox Imbalances in Ageing and Metabolic Alterations: Implications in Cancer and Cardiac Diseases. An Overview from the Working Group of Cardiotoxicity and Cardioprotection of the Italian Society of Cardiology (SIC)

Metabolic syndrome (MetS) is a well established risk factor for cardiovascular (CV) diseases. In addition, several studies indicate that MetS correlates with the increased risk of cancer in adults. The mechanisms linking MetS and cancer are not fully understood. Several risk factors involved in MetS are also cancer risk factors, such as the consumption of high calorie-food or high fat intake, low fibre intake, and sedentary lifestyle. Other common aspects of both cancer and MetS are oxidative stress and inflammation. In addition, some anticancer treatments can induce cardiotoxicity, including, for instance, left ventricular (LV) dysfunction and heart failure (HF), endothelial dysfunction and hypertension. In this review, we analyse several aspects of MetS, cancer and cardiotoxicity from anticancer drugs. In particular, we focus on oxidative stress in ageing, cancer and CV diseases, and we analyse the connections among CV risk factors, cancer and cardiotoxicity from anticancer drugs.

Differential Benefit of Adjuvant Docetaxel-Based Chemotherapy in Patients With Early Breast Cancer According to Baseline Body Mass Index

PURPOSE

Lipophilic drugs, such as taxanes, have a high affinity for adipose tissue and a resulting higher volume of distribution. Here, we reanalyzed clinical trial data to investigate whether the efficacy of docetaxel-based chemotherapy differs from non-docetaxel-based chemotherapy in patients with breast cancer according to their baseline body mass index (BMI).

PATIENTS AND METHODS

We retrospectively analyzed data from all of the patients in the adjuvant BIG 2-98 trial (ClinicalTrials.gov identifier: NCT00174655; N = 2,887) comparing non-docetaxel- to docetaxel-containing chemotherapy. BMI (kg/m²) was categorized as follows: 18.5 to < 25, lean; 25 to < 30, overweight; and ≥ 30, obese. Disease-free survival (DFS) was the primary endpoint, and overall survival (OS) was the secondary endpoint. A second-order interaction was assessed among treatment, BMI, and estrogen receptor (ER) status.

RESULTS

There was no difference in DFS or OS according to BMI in the non-docetaxel group, while reduced DFS and OS were observed with increasing BMI category in the docetaxel group. Adjusted hazard ratios for DFS and OS were, respectively, 1.12 (95% CI, 0.98 to 1.50; P = .21) and 1.27 (95% CI, 1.01 to 1.60; P = .04) for overweight versus lean groups and were 1.32 (95% CI, 1.08 to 1.62; P = .007) and 1.63 (95% CI, 1.27 to 2.09; P < .001), respectively, for obese versus lean groups. Similar results were obtained when considering ER-negative and ER-positive tumors separately and when considering only patients who received a relative dose intensity ≥ 85% for docetaxel. A joint modifying role of BMI and ER status on treatment effect was evident for DFS (adjusted P = .06) and OS (adjusted P = .04).

CONCLUSION

This retrospective analysis of a large adjuvant trial highlights a differential response to docetaxel according to BMI, which calls for a body composition-based re-evaluation of the risk-benefit ratio of the use of taxanes in breast cancer. These results now must be confirmed in additional series.

Lifestyle Intervention on Body Weight and Physical Activity in Patients with Breast Cancer can reduce the Risk of Death in Obese Women: The EMILI Study

Background obesity and sedentary lifestyle have been shown to negatively affect survival in breast cancer (BC). The purpose of this study was to test the efficacy of a lifestyle intervention on body mass index (BMI) and physical activity (PA) levels among BC survivors in Modena, Italy, in order to show an outcome improvement in obese and overweight patients. Methods: This study is a single-arm experimental design, conducted between November 2009 and May 2016 on 430 women affected by BC. Weight, BMI, and PA were assessed at baseline, at 12 months, and at the end of the study. Survival curves were estimated among normal, overweight, and obese patients. Results: Mean BMI decreased from baseline to the end of the study was equal to 2.9% (p = 0.065) in overweight patients and 3.3% in obese patients (p = 0.048). Mean PA increase from baseline to the end of the study was equal to 125% (p < 0.001) in normal patients, 200% (p < 0.001) in overweight patients and 100% (p < 0.001) in obese patients. After 70 months of follow-up, the 5-year overall survival (OS) rate was 96%, 96%, and 93%, respectively in normal, obese, and overweight patients. Overweight patients had significantly worse OS than normal ones (HR = 3.69, 95%CI = 1.82–4.53 p = 0.027) whereas no statistically significant differences were seen between obese and normal patients (HR 2.45, 95%CI = 0.68–8.78, p = 0.169). Conclusions: A lifestyle intervention can lead to clinically meaningful weight loss and increase PA in patients with BC. These results could contribute to improving the OS in obese patients compared to overweight ones.

The role of metabolic diseases in cardiotoxicity associated with cancer therapy: What we know, what we would know

Metabolic diseases, such as obesity and type 2 diabetes, are known risk factors for cardiovascular (CV) diseases. Thus, patients with those comorbidities could be at increased risk of experiencing cardiotoxicity related to treatment with Anthracyclines and the other new generation targeted anticancer drugs. However, investigations addressing the mechanisms underlying the development of CV complications and poor outcome in such cohort of patients are still few and controversial. Given the importance of a personalized approach against chemotherapy-induced cardiomyopathy, this review summarizes our current knowledge on the pathophysiology of chemotherapy-induced cardiomyopathy and its association with obesity and type 2 diabetes. Along with clinical evidences, future perspectives of preclinical research around this field and its role in addressing important open questions, including the development of more proactive strategies for prevention, and treatment of cardiotoxicity during and after chemotherapy in the presence of metabolic diseases, is also presented.

Impact of Obesity on Outcomes of Operable Breast Cancer: A Retrospective Cohort Study

Objective:

Obesity is increasing worldwide. Previous studies of the impact of obesity on breast cancer outcomes have reported conflicting results. We investigated the association of obesity and breast cancer survival in Thai patients.

Methods:

Medical records of operable breast cancer patients diagnosed and treated at Siriraj Hospital between January 2004 and December 2011 were reviewed. Demographic data, tumor characteristics, stage, treatment and adverse event were described. Obesity was defined as body mass index (BMI) ≥ 25 kg/m² using Asian’s cutoff value. Survivals in both obese and non-obese patient groups were analyzed.

Results:

A total of 400 patients were included, 200 in each group. Obese patients were older and associated with more comorbidity. Obesity was associated with larger tumor size (p = 0.011), greater numbers of lymph node involvement (p = 0.003) and more advanced stage (p = 0.01). Obese patients were more likely to receive less adjuvant chemotherapy and hormonal treatment. There was no statistically significant difference in disease-free survival (DFS) (Hazard ratio [HR] 0.72, 95% confidence interval [CI] 0.46 to 1.13) and overall survival (OS) (HR 0.77, 95% CI 0.43 to 1.39) between obese and non-obese patients. Interestingly, obesity was associated with fewer complications from chemotherapy than non-obese patients (p = 0.047).

Conclusion:

Obesity had no adverse prognostic impact association on both DFS and OS in Thai patients with operable breast cancer, although obese patients more often presented with larger tumor and higher numbers of lymph node involvement.

Decreased Efficacy of Doxorubicin Corresponds With Modifications in Lipid Metabolism Markers and Fatty Acid Profiles in Breast Tumors From Obese vs. Lean Mice

Breast cancer cells modulate lipid and fatty acid metabolism to sustain proliferation. The role of adipocytes in cancer treatment efficacy remains, however, to be fully elucidated. We investigated whether diet-induced obesity (DIO) affects the efficacy of doxorubicin treatment in a breast tumor-bearing mouse model. Female C57BL6 mice were fed a high fat or low fat diet for the full duration of the study (12 weeks). After 8 weeks, mice were inoculated with E0771 triple-negative breast cancer cells in the fourth mammary gland to develop breast tumor allographs. Tumor-bearing mice received either vehicle (Hank's balanced salt solution) or doxorubicin (chemotherapy). Plasma inflammatory markers, tumor, and mammary adipose tissue fatty acid composition, as well as protein expression of lipid metabolism markers were determined. The high fat diet (HFD) attenuated the treatment efficacy of doxorubicin. Both leptin and resistin concentrations were significantly increased in the HFD group treated with doxorubicin. Suppressed lipogenesis (decreased stearoyl CoA-desaturase-1) and lipolysis (decreased hormone-sensitive lipase) were observed in mammary adipose tissue of the DIO animals, whereas increased expression was observed in the tumor tissue of doxorubicin treated HFD mice. Obesogenic conditions induced altered tissue fatty acid (FA) compositions, which reduced doxorubicin's treatment efficacy. In mammary adipose tissue breast cancer cells suppressed the storage of FAs, thereby increasing the availability of free FAs and favored inflammation under obesogenic conditions.

Impact of BMI for clinical outcomes in Japanese breast cancer patients

OBJECTIVE

The relationship between the body mass index (BMI) at the time of breast cancer diagnosis and the prognosis of breast cancer patients has not yet been clarified. We investigated the impact of obesity for clinical outcomes in Japanese breast cancer patients.

METHODS

Women with primary breast cancer operated between 2002 and 2014 were identified. All patients are categorized into four groups according to BMI. The range of BMI is <18.5 kg/m2, from 18.5 to 24.9 kg/m2, 25 to 29.9 kg/m2, >30 kg/m2 in underweight, normal, overweight and obesity groups, respectively. The correlation between BMI and overall survival (OS), breast cancer-specific survival (BCSS) and disease-free survival (DFS) were statistically analyzed.

RESULTS

From the database of our institution, we identified 3223 patients. The median follow-up period was 57 months (1-149). We categorized 2257 (70.0%), 318 (9.9%), 545 (16.9%) and 103 (3.2%) patients into normal, underweight, overweight obesity groups respectively. There were189 patients (5.9%) deaths due to breast cancer recurrence (137 patients) and other disease (52 patients). Obesity groups was significantly high compared with normal groups for OS (adjusted HR, 2.43; 95% CI, 1.38-4.28; P < 0.001), BCSS (adjusted HR, 2.73; 95% CI, 1.15-6.44; P = 0.02) and DFS (adjusted HR, 1.83; 95% CI, 1.11-3.02; P = 0.017) by multivariate analysis. Especially, OS (adjusted HR, 4.87; 95% CI, 2.15-11.04; P < 0.001), BCSS (adjusted HR, 4.51; 95% CI, 1.52-13.34; P < 0.001) and DFS (adjusted HR, 4.87; 95% CI, 1.02-4.89; P = 0.04) were statistically insignificant in postmenopausal ER-positive breast cancer patients.

CONCLUSION

Obesity might be risk factor for OS, BCSS and DFS, especially postmenopausal ER-positive women.

Effect of Obesity on Neoadjuvant Systemic Therapy Outcomes in Patients with Early Breast Cancer: A Retrospective Institutional Study

BACKGROUND

Obesity and overweight are usually considered as poor prognostic factors in early breast cancer. Body mass index (BMI) is a significant predictive factor for lower pathologic complete response (pCR) rates after neo-adjuvant systemic therapy (NST). The relationship between obesity and breast cancer prognosis varies according to patient and tumor characteristics such as menopausal status and tumor subtype, respectively.

PATIENTS AND METHODS

Between March 2010 and October 2013, 80 patients with early breast cancer who had received standard NST from KFSH Saudi Arabia were included in this study. For statistical analysis, the study participants were categorized into two groups based on their BMI, as normal (BMI < 25 kg/m2) and obese groups (BMI ≥ 25 kg/m2). pCR was defined as non-invasive cancer in the breast/axillary tissue.

RESULTS

The median age of our patients was 48 (range, 38-68) years. Invasive ductal carcinoma (IDC) subtype was identified in 93.8% of the cases. Additionally, 26 (32.5%) and 33 (41.25%) patients were diagnosed with stage II and stage IIIA breast cancer, respectively. Lymphovascular invasion was detected in 32.5%, whereas intermediate and high-grade malignancy were found in 61.25% and 32.5% of the patients, respectively. Forty-four patients (55%) were obese. pCR was achieved in 56 patients (70%), and the comparison between patients with and without pCR revealed that those in the former group had significantly lower tumor grades. Significantly, lower relapse and mortality rates were distinguished in patients who achieved pCR than in those who did not. Additionally, comparison between normal and obese patients revealed that a high number of patients in both groups were post-menopausal (p = 0.001). However, survival analysis indicated the absence of significant differences in disease-free survival between the two groups based on BMI (p = 0.19). Conversely, patients with normal BMI had significantly better overall survival than obese patients (p = 0.029), with a higher mortality rate noted in the obese group (16.7% vs 2.3%, p = 0.037).

CONCLUSIONS

In the present study, 58.3% of patients that failed to achieve pCR had BMI above the normal level; they moreover had higher relapse rates and lower survival compared with normal BMI patients. This finding needs to be verified through further prospective studies to determine if BMI is a risk factor for breast cancer.

Impact of obesity on breast cancer recurrence and minimal residual disease

BACKGROUND

Obesity is associated with an increased risk of breast cancer recurrence and cancer death. Recurrent cancers arise from the pool of residual tumor cells, or minimal residual disease (MRD), that survives primary treatment and persists in the host. Whether the association of obesity with recurrence risk is causal is unknown, and the impact of obesity on MRD and breast cancer recurrence has not been reported in humans or in animal models.

METHODS

Doxycycline-inducible primary mammary tumors were generated in intact MMTV-rtTA;TetO-HER2/neu (MTB/TAN) mice or orthotopic recipients fed a high-fat diet (HFD; 60% kcal from fat) or a control low-fat diet (LFD; 10% kcal from fat). Following oncogene downregulation and tumor regression, mice were followed for clinical recurrence. Body weight was measured twice weekly and used to segregate HFD mice into obese (i.e., responders) and lean (i.e., nonresponders) study arms, and obesity was correlated with body fat percentage, glucose tolerance (measured using intraperitoneal glucose tolerance tests), serum biomarkers (measured by enzyme-linked immunosorbent assay), and tissue transcriptomics (assessed by RNA sequencing). MRD was quantified by droplet digital PCR.

RESULTS

HFD-Obese mice weighed significantly more than HFD-Lean and LFD control mice (p < 0.001) and had increased body fat percentage (p < 0.001). Obese mice exhibited fasting hyperglycemia, hyperinsulinemia, and impaired glucose tolerance, as well as decreased serum levels of adiponectin and increased levels of leptin, resistin, and insulin-like growth factor 1. Tumor recurrence was accelerated in HFD-Obese mice compared with HFD-Lean and LFD control mice (median relapse-free survival 53.0 days vs. 87.0 days vs. 80.0 days, log-rank p < 0.001; HFD-Obese compared with HFD-Lean HR 2.52, 95% CI 1.52-4.16; HFD-Obese compared with LFD HR 2.27, 95% CI 1.42-3.63). HFD-Obese mice harbored a significantly greater number of residual tumor cells than HFD-Lean and LFD mice (12,550 ± 991 vs. 7339 ± 2182 vs. 4793 ± 1618 cells, p < 0.001).

CONCLUSION

These studies provide a genetically engineered mouse model for study of the association of diet-induced obesity with breast cancer recurrence. They demonstrate that this model recapitulates physiological changes characteristic of obese patients, establish that the association between obesity and recurrence risk is causal in nature, and suggest that obesity is associated with the increased survival and persistence of residual tumor cells.

Body Mass Index at Diagnosis as a Prognostic Factor for Early-Stage Invasive Breast Cancer after Surgical Resection

BACKGROUND

The aim of this study was to investigate the association between body mass index (BMI) and prognosis of Chinese women with breast cancer.

PATIENTS AND METHODS

3,380 primary breast cancer patients who underwent surgery from 2010 to 2012 were selected and classified as low BMI group (BMI < 25.0) and high BMI group (BMI ≥ 25.0). The follow-up data for disease-free survival (DFS) and overall survival (OS) were obtained from 3,178 patients (median follow-up of 58 months). Cox regression analysis was used to evaluate the effect of BMI on DFS and OS.

RESULTS

The high BMI group showed more aggressive pathological features. BMI was negatively associated with OS (hazard ratio (HR) 1.33, 95% confidence interval (CI) 1.06-1.66; p = 0.012) but not DFS (HR 1.15, 95% CI 0.94-1.40; p = 0.17). Furthermore, when stratified by age, BMI was significantly and negatively associated with OS (HR 1.43, 95% CI 1.05-1.95; p = 0.025) in patients above 50 years of age, but this effect was not detected in younger patients.

CONCLUSION

BMI was an independent prognostic factor of OS in Chinese women with breast cancer, and age might be a mitigating factor. Among patients above 50 years of age, those with a high BMI were at greater risk of poor prognosis compared to individuals with a low BMI.

Adipocytes promote breast cancer resistance to chemotherapy, a process amplified by obesity: role of the major vault protein (MVP)

Introduction

Clinical studies suggest that obesity, in addition to promoting breast cancer aggressiveness, is associated with a decrease in chemotherapy efficacy, although the mechanisms involved remain elusive. As chemotherapy is one of the main treatments for aggressive or metastatic breast cancer, we investigated whether adipocytes can mediate resistance to doxorubicin (DOX), one of the main drugs used to treat breast cancer, and the mechanisms associated.

Methods

We used a coculture system to grow breast cancer cells with in vitro differentiated adipocytes as well as primary mammary adipocytes isolated from lean and obese patients. Drug cellular accumulation, distribution, and efflux were studied by immunofluorescence, flow cytometry, and analysis of extracellular vesicles. Results were validated by immunohistochemistry in a series of lean and obese patients with cancer.

Results

Adipocytes differentiated in vitro promote DOX resistance (with cross-resistance to paclitaxel and 5-fluorouracil) in a large panel of human and murine breast cancer cell lines independently of their subtype. Subcellular distribution of DOX was altered in cocultivated cells with decreased nuclear accumulation of the drug associated with a localized accumulation in cytoplasmic vesicles, which then are expelled into the extracellular medium. The transport-associated major vault protein (MVP), whose expression was upregulated by adipocytes, mediated both processes. Coculture with human mammary adipocytes also induced chemoresistance in breast cancer cells (as well as the related MVP-induced DOX efflux) and their effect was amplified by obesity. Finally, in a series of human breast tumors, we observed a gradient of MVP expression, which was higher at the invasive front, where tumor cells are at close proximity to adipocytes, than in the tumor center, highlighting the clinical relevance of our results. High expression of MVP in these tumor cells is of particular interest since they are more likely to disseminate to give rise to chemoresistant metastases.

Conclusions

Collectively, our study shows that adipocytes induce an MVP-related multidrug-resistant phenotype in breast cancer cells, which could contribute to obesity-related chemoresistance.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-1088-6) contains supplementary material, which is available to authorized users.

Fatty acids: Adiposity and breast cancer chemotherapy, a bad synergy?

Globally, breast cancer continues to be a major concern in women's health. Lifestyle related risk factors, specifically excess adipose tissue (adiposity) has reached epidemic proportions and has been identified as a major risk factor in the development of breast cancer. Dysfunctional adipose tissue has evoked research focusing on its association with metabolic-related conditions, breast cancer risk and progression. Adipose dysfunction in coordination with immune cells and inflammation, are responsible for accelerated cell growth and survival of cancer cells. Recently, evidence also implicates adiposity as a potential risk factor for chemotherapy resistance. Chemotherapeutic agents have been shown to negatively impact adipose tissue. Since adipose tissue is a major storage site for fatty acids, it is not unlikely that these negative effects may disrupt adipose tissue homeostasis. It is therefore argued that fatty acid composition may be altered due to the chemotherapeutic pharmacokinetics, which in turn could have severe health related outcomes. The underlying molecular mechanisms elucidating the effects of fatty acid composition in adiposity-linked drug resistance are still unclear and under explored. This review focuses on the potential role of adiposity in breast cancer and specifically emphasizes the role of fatty acids in cancer progression and treatment resistance.

Obesity-Linked Cancers: Current Knowledge, Challenges and Limitations in Mechanistic Studies and Rodent Models

The worldwide prevalence of obesity has doubled during the last 50 years, and according to the World Obesity Federation, one third of the people on Earth will be obese by the year 2025. Obesity is described as a chronic, relapsing and multifactorial disease that causes metabolic, biomechanical, and psychosocial health consequences. Growing evidence suggests that obesity is a risk factor for multiple cancer types and rivals smoking as the leading preventable cause for cancer incidence and mortality. The epidemic of obesity will likely generate a new wave of obesity-related cancers with high aggressiveness and shortened latency. Observational studies have shown that from cancer risk to disease prognosis, an individual with obesity is consistently ranked worse compared to their lean counterpart. Mechanistic studies identified similar sets of abnormalities under obesity that may lead to cancer development, including ectopic fat storage, altered adipokine profiles, hormone fluctuations and meta-inflammation, but could not explain how these common mechanisms produce over 13 different cancer types. A major hurdle in the mechanistic underpinning of obesity-related cancer is the lack of suitable pre-clinical models that spontaneously develop obesity-linked cancers like humans. Current approaches and animal models fall short when discerning the confounders that often coexist in obesity. In this mini-review, we will briefly survey advances in the different obesity-linked cancers and discuss the challenges and limitations in the rodent models employed to study their relationship. We will also provide our perspectives on the future of obesity-linked cancer research.

Percent Body Fat Change in Chinese Women After Adjuvant Chemotherapy for Breast Cancer

BACKGROUND Weight gain is a common side effect observed in breast cancer (BC) patients undergoing adjuvant chemotherapy, although the characteristics and mechanism are not been fully understood. This study aimed to investigate percent body fat (%BF) change, and identify the associated risk factors among Chinese women receiving chemotherapy for BC. MATERIAL AND METHODS A prospective longitudinal study was conducted on a cohort of 140 Chinese female patients with BC between June 2016 and October 2017. Data on demographic and clinical features were collected using a standard protocol. Anthropometric parameters including body weight and %BF were measured before and after chemotherapy. Multiple logistic analysis was performed to identify the risk factors for %BF change. RESULTS A total of 52.9% and 58.6% of the 140 patients experienced gains in weight and %BF after chemotherapy, respectively, with mean increases of 2.1±1.9 kg and 1.3±2.2%, respectively. Fifty-eight patients gained %BF over 2.5% of the baseline value. Moreover, premenopausal women had a greater mean %BF gain than postmenopausal women (P=0.018). Logistic analysis showed that premenopausal status, younger age, multi-agent chemotherapy regimen, high-calorie diet, and decreased physical activity were independent variables that inducted %BF gain. CONCLUSIONS %BF gain occurred frequently in Chinese women after adjuvant chemotherapy for BC, especially in premenopausal women. An effort should be made to the management of %BF.

Impact of change in body mass index during neoadjuvant chemotherapy and survival among breast cancer subtypes

PURPOSE

We hypothesized that an increase in BMI category during neoadjuvant chemotherapy (NAC) would be associated with pathological complete response (pCR) rate and worse survival outcomes in primary breast cancer patients.

METHODS

We reviewed the records of 4029 patients with stage I-III breast cancer who had undergone NAC and definitive surgery at our institution between May 1, 1990 and April 30, 2013. BMI values at baseline and after NAC were recorded, and the corresponding BMI category was assessed with the WHO classification. Overall survival (OS) and recurrence-free survival (RFS) were estimated using the Kaplan-Meier method, and multivariate Cox regression models were used to estimate the effect of covariates of interest on OS and RFS.

RESULTS

The median follow-up period was 3.95 years. A change in BMI category from normal to obese during NAC was independently associated with shorter OS duration than was maintaining a normal weight [hazard ratio (HR) 1.637; 95%CI 1.066-2.514; p = 0.0242]. Kaplan-Meier curves among breast cancer subtypes showed differences, and a decrease in BMI led to better RFS and OS rates in obese patients with HR+/HER2- disease; those who maintained BMI also showed better prognosis for triple-negative breast cancer (TNBC). We saw no association between BMI change and pCR rate.

CONCLUSION

Our data suggest that inability to maintain normal weight during NAC is a predictive marker of poor survival but not pCR. It may be important for patients to maintain a normal weight during NAC.

Early breast cancer: why does obesity affect prognosis?

High BMI is associated with an increased risk of breast cancer in post-menopausal women but poorer outcomes in all age groups. The underlying mechanism is likely to be multi-factorial. Patients with a high BMI may present later due to body habitus. Some studies have also indicated an increased incidence of biologically adverse features, including a higher frequency of oestrogen receptor (ER negative) tumours, in obese patients. Obese patients have a higher frequency of surgical complications, potentially delaying systemic therapies, and reports suggest that chemotherapy and endocrine therapy are less effective in patients with BMI ≥30 kg/m2.High BMI is generally interpreted as excess adiposity and a World Cancer Research Fund report judged that the associations between BMI and incidence of breast cancer were due to body fatness. However, BMI cannot distinguish lean mass from fat mass, or characterise body fat distribution. Most chemotherapy drugs are dosed according to calculated body surface area (BSA). Patients with a similar BSA or BMI may have wide variations in their distribution of adipose tissue and skeletal muscle (body composition); however, few studies have looked at the effect of this on chemotherapy tolerance or effectiveness. Finally, adjuvant treatments for breast cancer can themselves result in body composition changes.Research is required to fully understand the biological mechanisms by which obesity influences cancer behaviour and the impact of obesity on treatment effectiveness and tolerance so that specific management strategies can be developed to improve the prognosis of this patient group.

Association between obesity with disease-free survival and overall survival in triple-negative breast cancer: A meta-analysis

OBJECTIVE

To investigate the relationship between obesity and disease-free survival (DFS) and overall survival (OS) of triple-negative breast cancer.

METHODS

Citations were searched in PubMed, Cochrane Library, and Web of Science. Random effect model meta-analysis was conducted by using Revman software version 5.0, and publication bias was evaluated by creating Egger regression with STATA software version 12.

RESULTS

Nine studies (4412 patients) were included for DFS meta-analysis, 8 studies (4392 patients) include for OS meta-analysis. There were no statistical significances between obesity with DFS (P = .60) and OS (P = .71) in triple-negative breast cancer (TNBC) patients.

CONCLUSION

Obesity has no impact on DFS and OS in patients with TNBC.

PTGS2 polymorphism rs689466 favors breast cancer recurrence in obese patients

Breast cancer is the leading cancer among women, and its increasing incidence is a challenge worldwide. Estrogen exposure is the main risk factor, but obesity among postmenopausal women has been shown to favor disease onset and progression. The link between obesity and mammary carcinogenesis involves elevated estrogen production and proinflammatory stimuli within the adipose tissue, with activation of the cyclooxygenase-2 pathway. Here, we evaluate the impact of the four most common cyclooxygenase-2 gene polymorphisms (rs689465, rs689466, rs20417 and rs20417), in combination with obesity, on the risk of breast cancer progression in a cohort of Brazilian breast cancer patients (N = 1038). Disease-free survival was evaluated using Kaplan-Meier curves, with multivariate Cox proportional hazards regression models for calculation of adjusted hazard ratios (HR_adj). Obesity did not affect disease progression, whereas rs689466 variant genotypes increased the recurrence risk among obese patients (HR_adj = 2.5; 95% CI = 1.4-4.3), either for luminal (HR_adj = 2.2; 95% CI = 1.1-4.2) or HER2-like and triple-negative tumors (HR_adj = 3.2; 95% CI = 1.2-8.5). Likewise, the haplotype *4, which contains variant rs689466, was associated with shorter disease-free survival among obese patients (HR_adj = 3.3; 95% CI = 1.8-6.0), either in luminal (HR_adj = 3.5; 95% CI = 1.6-7.3) or HER2-like and triple-negative (HR_adj = 3.1; 95% CI = 1.1-8.9) tumors. Such deleterious impact of variant rs689466 on disease-free survival of obese breast cancer patients was restricted to postmenopausal women. In conclusion, cyclooxygenase-2 genotyping may add to the prognostic evaluation of obese breast cancer patients.

Chemoresistance: Intricate Interplay Between Breast Tumor Cells and Adipocytes in the Tumor Microenvironment

Excess adipose tissue is a hallmark of an overweight and/or obese state as well as a primary risk factor for breast cancer development and progression. In an overweight/obese state adipose tissue becomes dysfunctional due to rapid hypertrophy, hyperplasia, and immune cell infiltration which is associated with sustained low-grade inflammation originating from dysfunctional adipokine synthesis. Evidence also supports the role of excess adipose tissue (overweight/obesity) as a casual factor for the development of chemotherapeutic drug resistance. Obesity-mediated effects/modifications may contribute to chemotherapeutic drug resistance by altering drug pharmacokinetics, inducing chronic inflammation, as well as altering tumor-associated adipocyte adipokine secretion. Adipocytes in the breast tumor microenvironment enhance breast tumor cell survival and decrease the efficacy of chemotherapeutic agents, resulting in chemotherapeutic resistance. A well-know chemotherapeutic agent, doxorubicin, has shown to negatively impact adipose tissue homeostasis, affecting adipose tissue/adipocyte functionality and storage. Here, it is implied that doxorubicin disrupts adipose tissue homeostasis affecting the functionality of adipose tissue/adipocytes. Although evidence on the effects of doxorubicin on adipose tissue/adipocytes under obesogenic conditions are lacking, this narrative review explores the potential role of obesity in breast cancer progression and treatment resistance with inflammation as an underlying mechanism.

Body mass index and breast cancer survival: a Mendelian randomization analysis

Background

There is increasing evidence that elevated body mass index (BMI) is associated with reduced survival for women with breast cancer. However, the underlying reasons remain unclear. We conducted a Mendelian randomization analysis to investigate a possible causal role of BMI in survival from breast cancer.

Methods

We used individual-level data from six large breast cancer case-cohorts including a total of 36 210 individuals (2475 events) of European ancestry. We created a BMI genetic risk score (GRS) based on genotypes at 94 known BMI-associated genetic variants. Association between the BMI genetic score and breast cancer survival was analysed by Cox regression for each study separately. Study-specific hazard ratios were pooled using fixed-effect meta-analysis.

Results

BMI genetic score was found to be associated with reduced breast cancer-specific survival for estrogen receptor (ER)-positive cases [hazard ratio (HR) = 1.11, per one-unit increment of GRS, 95% confidence interval (CI) 1.01-1.22, P = 0.03). We observed no association for ER-negative cases (HR = 1.00, per one-unit increment of GRS, 95% CI 0.89-1.13, P = 0.95).

Conclusions

Our findings suggest a causal effect of increased BMI on reduced breast cancer survival for ER-positive breast cancer. There is no evidence of a causal effect of higher BMI on survival for ER-negative breast cancer cases.