Obesity is an independent predictor of poor survival in metastatic breast cancer: retrospective analysis of a patient cohort whose treatment included high-dose chemotherapy and autologous stem cell support

The effect of BMI on survival outcome of breast cancer patients: a systematic review and meta-analysis

OBJECTIVE

The main goal of the present research is to explore the potential link of body mass index (BMI) with different survival metrics in breast cancer patients. Our aim is to offer the latest and most thorough meta-analysis, assessing the strength and reliability of the connection that BMI has with prognostic indicators in this disease.

PATIENTS AND METHODS

As of January 2024, we conducted a systematic literature search across PubMed, Embase, Web of Science, and the Cochrane Library databases. Our search aimed to identify studies examining BMI as an exposure factor, with breast cancer patients constituting the study population, and utilizing adjusted hazard ratio (HR) as the data type of interest.

RESULTS

The evidence synthesis incorporated a total of 61 eligible articles involving 201,006 patients. Being underweight posed a risk factor for overall survival (OS) in breast cancer patients compared to normal weight (HR 1.15, 95% CI 0.98-1.35; P = 0.08). Overweight or obesity, in comparison to normal weight, was a risk factor for OS (HR 1.18, 95% CI 1.14-1.23; P < 0.00001), disease-free survival (DFS) (HR 1.11, 95% CI 1.08-1.13; P < 0.00001), relapse-free survival (RFS) (HR 1.14, 95% CI 1.06-1.22; P = 0.03), and breast cancer-specific survival (BCSS) (HR 1.18, 95% CI 1.11-1.26; P < 0.00001), but not for progression-free survival (PFS) (HR 0.91, 95% CI 0.76-1.10; P = 0.33). Notably, in subgroup analyses, overweight patients achieved prolonged PFS (HR 0.80, 95% CI 0.64-0.99; P = 0.04), and compared to the obese population, the overweight cohort exhibited a significant difference in OS (HR 1.11, 95% CI 1.05-1.16; P < 0.00001) and DFS (HR 1.06, 95% CI 1.03-1.10; P = 0.0004), with a considerably stronger association. Furthermore, compared to HER- patients, HER + patients exhibited a greater predictive value for OS (HR 1.23, 95% CI 1.10-1.37; P = 0.0004), RFS (HR 1.30, 95% CI 1.03-1.64; P < 0.00001), and DFS (HR 1.10, 95% CI 1.03-1.17; P = 0.003).

CONCLUSIONS

The results of our meta-analysis reveal a notable association between BMI and various survival measures in breast cancer prognosis. These findings provide a solid basis for predicting breast cancer outcomes and implementing more effective therapeutic approaches.

Association of body composition and survival in patients with locally advanced breast cancer: a historical cohort study

BACKGROUND

Altered body composition has been attributed to major health problems globally, particularly in patients with cancer. To date, there have not been sufficient indices for body compositions in predicting the survival of locally advanced breast cancer (LABC).

PURPOSE

To assess the association between body composition and overall survival (OS) as well as disease-free survival (DFS) in patients with LABC.

MATERIAL AND METHODS

A retrospective study was conducted of patients with LABC diagnosed between 2010 and 2018. Body composition parameters, including skeletal muscle and adiposity parameters, were measured using computed tomography at the L3 vertebra using in-house software developed by MATLAB and freeware Python 3.6.13. The association between body composition and OS and DFS were analyzed using a log-rank test and multivariate Cox-proportional hazard regression.

RESULTS

Of 199 patients, 72 (36%) died during the follow-up period (range = 3.8-150.7 months). Median survival was 101 months. Low visceral-to-subcutaneous ratio ≤0.3 (adjusted hazard ratio [aHR] = 2.57, 95% confidence interval [CI] = 1.51-4.37; aHR = 2.46, 95% CI = 1.33-4.56), and high composite fat (aHR = 3.26, 95% CI = 1.69-6.29; aHR = 2.19, 95% CI = 1.11-4.3) were associated with lower OS and DFS. Positive lymph nodes ≥3, progesterone receptor negative, and total radiation dose >5000 cGy significantly decreased both OS and DFS. A history of previous treatment before body composition assessment and surgery had a protective effect on OS and DFS. No association of sarcopenia, body mass index, and adiposity areas with survival outcomes was observed.

CONCLUSION

Low visceral-to-subcutaneous ratio and high composite fat were independent prognostic factors for OS and DFS in patients with LABC. However, other body composition parameters showed no effect on survival.

The prognostic impact of BMI in patients with HR+/HER2- advanced breast cancer: a study of the SONABRE registry

PURPOSE

This study determines the prognostic impact of body mass index (BMI) in patients with hormone receptor-positive/human epidermal growth factor receptor-2-negative (HR+/HER2-) advanced (i.e., metastatic) breast cancer (ABC).

METHODS

All patients with HR+/HER2- ABC who received endocrine therapy +-a cyclin-dependent kinase 4/6 inhibitor as first-given systemic therapy in 2007-2020 in the Netherlands were identified from the Southeast Netherlands Advanced Breast Cancer (SONABRE) registry (NCT03577197). Patients were categorised as underweight (BMI: < 18.5 kg/m2), normal weight (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), or obese (≥ 30.0 kg/m2). Overall survival (OS) and progression-free survival (PFS) were compared between BMI classes using multivariable Cox regression analyses.

RESULTS

This study included 1456 patients, of whom 35 (2%) were underweight, 580 (40%) normal weight, 479 (33%) overweight, and 362 (25%) obese. No differences in OS were observed between normal weight patients and respectively overweight (HR 0.99; 95% CI 0.85-1.16; p = 0.93) and obese patients (HR 1.04; 95% CI 0.88-1.24; p = 0.62). However, the OS of underweight patients (HR 1.45; 95% CI 0.97-2.15; p = 0.07) tended to be worse than the OS of normal weight patients. When compared with normal weight patients, the PFS was similar in underweight (HR 1.05; 95% CI 0.73-1.51; p = 0.81), overweight (HR 0.90; 95% CI 0.79-1.03; p = 0.14), and obese patients (HR 0.88; 95% CI 0.76-1.02; p = 0.10).

CONCLUSION

In this study among 1456 patients with HR+/HER2- ABC, overweight and obesity were prevalent, whereas underweight was uncommon. When compared with normal weight, overweight and obesity were not associated with either OS or PFS. However, underweight seemed to be an adverse prognostic factor for OS.

Lysine metabolism is a novel metabolic tumor suppressor pathway in breast cancer

The International Agency for Research on Cancer determined that obesity is the primary preventable cause of breast cancer. The nuclear receptor peroxisome proliferator activated receptor γ (PPARγ) binds inflammatory mediators in obesity and its expression is reduced in human breast cancer. We created a new model to better understand how the obese microenvironment alters nuclear receptor function in breast cancer. The obesity related cancer phenotype was PPARγ dependent; deletion of PPARγ in mammary epithelium which is a tumor suppressor in lean mice unexpectedly increased tumor latency, reduced the luminal progenitor (LP) tumor cell fraction, and increased autophagic and senescent cells. Loss of PPARγ expression in mammary epithelium of obese mice increased expression of 2-aminoadipate semialdehyde synthase (AASS) which regulates lysine catabolism to acetoacetate. PPARγ-associated co-repressors and activators regulated AASS expression via a canonical response element. AASS expression was significantly reduced in human breast cancer, and AASS overexpression or acetoacetate treatment inhibited proliferation and induced autophagy and senescence in human breast cancer cell lines. Genetic or pharmacologic HDAC inhibition promoted autophagy and senescence in mammary tumor cells in vitro and in vivo. We concluded that lysine metabolism is a novel metabolic tumor suppressor pathway in breast cancer.

The role of bone marrow adipocytes in cancer progression: the impact of obesity

Bone marrow adipose tissues (BMATs) and their main cellular component, bone marrow adipocytes (BMAds), are found within the bone marrow (BM), which is a niche for the development of hematological malignancies as well as bone metastasis from solid tumors such as breast and prostate cancers. In humans, BMAds are present within the hematopoietic or "red" BMAT and in the "yellow" BMAT where they are more densely packed. BMAds are emerging as new actors in tumor progression; however, there are many outstanding questions regarding their precise role. In this review, we summarized our current knowledge regarding the development, distribution, and regulation by external stimuli of the BMATs in mice and humans and addressed how obesity could affect these traits. We then discussed the specific metabolic phenotype of BMAds that appear to be different from "classical" white adipocytes, since they are devoid of lipolytic function. According to this characterization, we presented how tumor cells affect the in vitro and in vivo phenotype of BMAds and the signals emanating from BMAds that are susceptible to modulate tumor behavior with a specific emphasis on their metabolic crosstalk with cancer cells. Finally, we discussed how obesity could affect this crosstalk. Deciphering the role of BMAds in tumor progression would certainly lead to the identification of new targets in oncology in the near future.

Computed tomography based analyses of body mass composition in HER2 positive metastatic breast cancer patients undergoing first line treatment with pertuzumab and trastuzumab

Body composition parameters (BCp) have been associated with outcome in different tumor types. However, their prognostic value in patients with HER2-positive metastatic breast cancer (BC) receiving first line treatment with dual anti-HER2 antibody blockade is unknown. Preclinical evidences suggest that adipocytes adjacent to BC cells can influence response to anti-HER2 treatments. We retrospectively analyzed Computed Tomography (CT)-based BCp from 43 patients with HER2-positive metastatic BC who received first line pertuzumab/trastuzumab-based treatment between May 2009 and March 2020. The impact of baseline CT-based BCp on progression-free survival (PFS) was tested using Kaplan–Meier estimates and univariate and multivariate Cox regression models. We found a significantly worse PFS for patients with high baseline subcutaneous fat index (median 7.9 vs 16.1 months, p = 0.047, HR = 2.04, 95%CI 1–4.17) and for those with high total abdominal fat index (8.1 vs 18.8 months, p = 0.030, HR = 2.17, 95%CI 1.06–4.46). Patients with baseline sarcopenia did not show shorter PFS compared to those without sarcopenia (10.4 vs 9.2 months, p = 0.960, HR = 0.98, 95%CI 0.47–2.03). Total abdominal fat index remained a significant predictor of PFS at multivariate analysis. Our findings suggest that a high quantity of total abdominal fat tissue is a poor prognostic factor in patients receiving trastuzumab/pertuzumab-based first-line treatment for HER2-positive metastatic BC.

The role of obesity and bariatric surgery-induced weight loss in breast cancer

Obesity is a complex metabolic condition considered a worldwide public health crisis, and a deeper mechanistic understanding of obesity-associated diseases is urgently needed. Obesity comorbidities include many associated cancers and are estimated to account for 20% of female cancer deaths in the USA. Breast cancer, in particular, is associated with obesity and is the focus of this review. The exact causal links between obesity and breast cancer remain unclear. Still, interactions have emerged between body mass index, tumor molecular subtype, genetic background, and environmental factors that strongly suggest obesity influences the risk and progression of certain breast cancers. Supportive preclinical research uses various diet-induced obesity models to demonstrate that weight loss, via dietary interventions or changes in energy expenditure, reduces the onset or progression of breast cancers. Ongoing and future studies are now aimed at elucidating the underpinning mechanisms behind weight-loss-driven observations to improve therapy and outcomes in patients with breast cancer and reduce risk. This review aims to summarize the rapidly emerging literature on obesity and weight loss strategies with a focused discussion of bariatric surgery in both clinical and preclinical studies detailing the complex interactions between metabolism, immune response, and immunotherapy in the setting of obesity and breast cancer.

Metformin and tBHQ Treatment Combined with an Exercise Regime Prevents Osteosarcopenic Obesity in Middle-Aged Wistar Female Rats

Osteosarcopenic obesity (OSO) is characterized by bone density, mass, and muscle strength loss, in conjunction with adipose tissue increase. OSO impairs physical activity and mobility, provoking autonomy loss; also, it is known that augmenting body fat in the elderly decreases life expectancy. The main factors influencing this health deterioration are the inflammatory environment induced by adipose tissue and its infiltration into muscle tissue, which leads to oxidative stress generation. Currently, there are several treatments to delay OSO, among which exercise training stands out because it improves muscle fiber quality and quantity and decreases adipose tissue. We have recently demonstrated that the combined treatment between moderate exercise and metformin slows sarcopenia's onset by a mechanism that includes adipose reduction and REDOX regulation. On the other hand, tert-butylhydroquinone (tBHQ) is a well-known antioxidant that counteracts oxidative stress. Therefore, to slow down obesity's harmful effects on muscle mass and bone mineral density, we performed different interventions, including combining a Fartlek-type exercise routine with metformin and tBHQ administration, in a model of middle-aged female Wistar rats with obesity induced with a hypercaloric diet. Our results showed that the combined exercise-metformin-tBHQ treatment increased muscle mass and strength, decreased body weight, body mass index, and fat percentage, and improved redox status, thus increasing animal survival.

Chemopreventive and Anticancer Property of Selenoproteins in Obese Breast Cancer

Obesity is a significant risk factor for various cancers including breast cancer resulting in an increased risk of recurrence as well as morbidity and mortality. Extensive studies on various pathways have been successful in establishing a biological relationship between obesity and breast cancer. The molecular classification of breast cancer includes five groups each having different responses to treatment. Increased levels of inflammatory cytokines seen in obese conditions drive the pro-proliferative pathways, such as the influx of macrophages, angiogenesis, and antiapoptotic pathways. Increased peripheral aromatization of androgens by aromatase increases the circulating estrogen levels which are also responsible for the association of obesity with breast cancer. Also, increased oxidative stress due to chronic low-grade inflammation in obese women plays an important role in carcinogenesis. Despite the availability of safe and effective treatment options for breast cancer, obese women are at increased risk of adverse outcomes including treatment-related toxicities. In the recent decade, selenium compounds have gained substantial interest as chemopreventive and anticancer agents. The chemical derivatives of selenium include inorganic and organic compounds that exhibit pro-oxidant properties and alter cellular redox homeostasis. They target more than one metabolic pathway by thiol modifications, induction of reactive oxygen species, and chromatin modifications to exert their chemopreventive and anticancer activities. The primary functional effectors of selenium that play a significant role in human homeostasis are selenoproteins like glutathione peroxidase, thioredoxin reductase, iodothyronine deiodinases, and selenoprotein P. Selenoproteins play a significant role in adipose tissue physiology by modulating preadipocyte proliferation and adipogenic differentiation. They correlate negatively with body mass index resulting in increased oxidative stress that may lead to carcinogenesis in obese individuals. Methylseleninic acid effectively suppresses aromatase activation thus reducing the estrogen levels and acting as a breast cancer chemopreventive agent. Adipose-derived inflammatory mediators influence the selenium metabolites and affect the proliferation and metastatic properties of cancer cells. Recently selenium nanoparticles have shown potent anticancer activity which may lead to a major breakthrough in the management of cancers caused due to multiple pathways. In this review, we discuss the possible role of selenoproteins as chemopreventive and an anticancer agent in obese breast cancer.

The obesity paradox in early and advanced HER2 positive breast cancer: pooled analysis of clinical trial data

While many studies have evaluated the relationship between BMI and breast cancer outcomes, it is unclear whether this relationship is consistent between early breast cancer (BC) and advanced BC. The study included 5099 patients with HER2 positive early BC (EBC) and 3496 with HER2 positive advanced BC (ABC). In the EBC cohort, higher BMI was associated with worse overall survival (OS) (HR [95% CI]: overweight = 1.30 [1.13-1.51]; obese = 1.37 [1.14-1.64], P = < 0.001), and worse disease-free survival (overweight = 1.10 [0.98-1.24]; obese = 1.20 [1.04-1.39], P = 0.061). In contrast, for the ABC cohort, higher BMI was significantly associated with improved OS (overweight = 0.85 [0.76-0.96]; obese = 0.82 [0.72-0.95], P = 0.014), and progression-free survival (overweight = 0.91 [0.83-1.01]; obese = 0.87 [0.77-0.98], P = 0.034). In this large high-quality dataset, higher BMI was independently associated with worse survival in EBC, paradoxically in ABC higher BMI was independently associated with improved survival.

Impact of body mass index on overall survival in patients with metastatic breast cancer

BACKGROUND

High Body mass index (BMI) is a risk factor for breast cancer among postmenopausal women and an adverse prognostic factor in early-stage. Little is known about its impact on clinical outcomes in patients with metastatic breast cancer (MBC).

METHODS

The National ESME-MBC observational cohort includes all consecutive patients newly diagnosed with MBC between Jan 2008 and Dec 2016 in the 18 French comprehensive cancer centers.

RESULTS

Of 22 463 patients in ESME-MBC, 12 999 women had BMI data available at MBC diagnosis. Median BMI was 24.9 kg/m² (range 12.1-66.5); 20% of women were obese and 5% underweight. Obesity was associated with more de novo MBC, while underweight patients had more aggressive cancer features. Median overall survival (OS) of the BMI cohort was 47.4 months (95% CI [46.2-48.5]) (median follow-up: 48.6 months). Underweight was independently associated with a worse OS (median OS 33 months; HR 1.14, 95%CI, 1.02-1.27) and first line progression-free survival (HR, 1.11; 95%CI, 1.01; 1.22), while overweight or obesity had no effect.

CONCLUSION

Overweight and obesity are not associated with poorer outcomes in women with metastatic disease, while underweight appears as an independent adverse prognostic factor.

Comparison between body composition parameters and response to neoadjuvant chemotherapy by using pre-treatment PET CT in locally advanced breast cancer

•

Weight and the BMI are inadequate proxies for adiposity that do not distinguish between muscle and adipose tissue or different specific deposits of adipose tissue (visceral and subcutaneous), which have different physiological effects.

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Patients with the same BMI are likely to have different anatomical distribution of adipose and muscle tissue.

•

To our knowledge, only few studies have investigated the association between fat and muscle tissue distribution of the body, and response to neoadjuvant chemotherapy.

Purpose

To compare the adipose and muscle tissue areas in patients who responded differently to neoadjuvant chemotherapy.

Methods

One hundred and eighty six patients diagnosed with breast cancer who underwent neoadjuvant chemotherapy between January 2015- October 2019 and were operated after the treatment were retrospectively included in the study. Pathological results were divided into five groups using the Miller-Payne grading systems. Grade 1 indicating no significant reduction in malignant cells; Grade 2: a minor loss of malignant cells (≤ 30 %); Grade 3: reduction in malignant cells between 30 % and 90 %; Grade 4: disappearance of malignant cells >90 %; Grade 5: no malignant cells identifiable. Pre-treatment PET CT scans were evaluated, and calculation of body composition parameters were performed on a single axial section passing through the L3 vertebrae. Spearman’s correlation test was used to analyze the correlation between SAT, VAT, MT parameters and pathological responses.

Results

There was no strong correlation between the 5 groups separated according to neoadjuvant chemotherapy treatment response and tissue distributions. However, that there was a very low correlation found between superficial adipose tissue and pathological response (r=, 156).

Conclusion

In conclusion, our results have provided a very low correlation between SAT and more than 30 % response. More research is required to evaluate the role of the body fat and muscle parameters in response to neoadjuvant chemotherapy in larger patient populations.

Microbiome, bile acids, and obesity: How microbially modified metabolites shape anti-tumor immunity

Bile acids (BAs) are known facilitators of nutrient absorption but recent paradigm shifts now recognize BAs as signaling molecules regulating both innate and adaptive immunity. Bile acids are synthesized from cholesterol in the liver with subsequent microbial modification and fermentation adding complexity to pool composition. Bile acids act on several receptors such as Farnesoid X Receptor and the G protein-coupled BA receptor 1 (TGR5). Interestingly, BA receptors (BARs) are expressed on immune cells and activation either by BAs or BAR agonists modulates innate and adaptive immune cell populations skewing their polarization toward a more tolerogenic anti-inflammatory phenotype. Intriguingly, recent evidence also suggests that BAs promote anti-tumor immune response through activation and recruitment of tumoricidal immune cells such as natural killer T cells. These exciting findings have redefined BA signaling in health and disease wherein they may suppress inflammation on the one hand, yet promote anti-tumor immunity on the other hand. In this review, we provide our readers with the most recent understanding of the interaction of BAs with the host microbiome, their effect on innate and adaptive immunity in health and disease with a special focus on obesity, bariatric surgery-induced weight loss, and immune checkpoint blockade in cancer.

Impact of body composition on outcome in patients with early breast cancer

PURPOSE

We investigated the impact of body composition on outcomes of patients with early breast cancer. Skeletal muscle mass, visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and muscle fat infiltration or inter-muscular adipose tissue areas (IMAT), obtained by computed tomography (CT), were assessed.

METHODS

A total of 119 female patients who had breast cancer were included in this retrospective study. The total skeletal muscle and fat tissue areas were evaluated in two adjacent axial slices obtained at the third lumbar vertebra by CT used for disease staging. The women were assigned to either a sarcopenia or non-sarcopenia group based on their skeletal muscle index (cut-off 41.0 cm2/m2). They also were classified into high and low VAT/SAT ratio groups and assigned to either the high or low IMAT index group. The association of the body composition parameters and prognosis was statistically analyzed.

RESULTS

Among the 119 evaluable patients, 58 were sarcopenic (48.8%), 55 (46.2%) had a high VAT/SAT ratio, and 62 (52.1%) had a high IMAT index. Median follow-up was 52.4 months. Multivariate analysis revealed sarcopenia and IMAT index as independent prognostic factors for disease-free survival (p = 0.02 and p = 0.04, respectively) and overall survival (p = 0.05 and p = 0.02, respectively). BMI was not significantly associated with disease-free survival, but a trend was observed (p = 0.09).

CONCLUSIONS

Sarcopenia and IMAT index are independent prognostic factors in early breast cancer; therefore, assessing body composition could be a simple and useful approach to integrate into patient management.

Contribution of Adipose Tissue to Development of Cancer

Solid tumor growth and metastasis require the interaction of tumor cells with the surrounding tissue, leading to a view of tumors as tissue-level phenomena rather than exclusively cell-intrinsic anomalies. Due to the ubiquitous nature of adipose tissue, many types of solid tumors grow in proximate or direct contact with adipocytes and adipose-associated stromal and vascular components, such as fibroblasts and other connective tissue cells, stem and progenitor cells, endothelial cells, innate and adaptive immune cells, and extracellular signaling and matrix components. Excess adiposity in obesity both increases risk of cancer development and negatively influences prognosis in several cancer types, in part due to interaction with adipose tissue cell populations. Herein, we review the cellular and noncellular constituents of the adipose "organ," and discuss the mechanisms by which these varied microenvironmental components contribute to tumor development, with special emphasis on obesity. Due to the prevalence of breast and prostate cancers in the United States, their close anatomical proximity to adipose tissue depots, and their complex epidemiologic associations with obesity, we particularly highlight research addressing the contribution of adipose tissue to the initiation and progression of these cancer types. Obesity dramatically modifies the adipose tissue microenvironment in numerous ways, including induction of fibrosis and angiogenesis, increased stem cell abundance, and expansion of proinflammatory immune cells. As many of these changes also resemble shifts observed within the tumor microenvironment, proximity to adipose tissue may present a hospitable environment to developing tumors, providing a critical link between adiposity and tumorigenesis. © 2018 American Physiological Society. Compr Physiol 8:237-282, 2018.

The impact of baseline body mass index on clinical outcomes in metastatic breast cancer: a prospective study

OBJECTIVE

The prognostic value of body mass index (BMI) in metastatic breast cancer (MBC) has not been fully elucidated. In a prospective study to investigate the chemo-sensitizing effect of statins on clinical outcomes in MBC patients who were scheduled to receive palliative chemotherapy (Carboplatin and Vinorelbine), we sought to investigate the relationship between baseline BMI and clinical outcomes; response, overall survival (OS) and progression free survival (PFS), over a median follow-up of 40-months.

RESULTS

Eighty-Two MBC patients were enrolled and categorized using baseline BMI as underweight (BMI, < 18.5 kg/m2, n = 1), normal-weight (BMI, 18.5-24.9 kg/m2, n = 20), overweight (BMI, 25-29.9 kg/m2, n = 34), and obese (BMI, ≥ 30 kg/m2, n = 27). Median OS was 10 months in normal/underweight, 19 months in overweight, and 16 months in obese (P = 0.083). Univariate Cox model revealed that overweight patients were significantly less likely to die of MBC as normal BMI patients (hazard ratio [HR] = 0.54, 95% confidence interval [CI], (0.29-0.98), P = 0.044). Similarly, multivariate Cox model, after adjusting for age, number of metastatic sites, chemotherapy line's grade, HER2 and hormone receptors status, confirmed longer survivorship of overweight in comparison with normal BMI patients (HR = 0.51, 95% CI (0.26-0.99), P = 0.047). Our data suggest that being overweight could improve OS in MBC patients.

Omentum and bone marrow: how adipocyte-rich organs create tumour microenvironments conducive for metastatic progression

A number of clinical studies have linked adiposity with increased cancer incidence, progression and metastasis, and adipose tissue is now being credited with both systemic and local effects on tumour development and survival. Adipocytes, a major component of benign adipose tissue, represent a significant source of lipids, cytokines and adipokines, and their presence in the tumour microenvironment substantially affects cellular trafficking, signalling and metabolism. Cancers that have a high predisposition to metastasize to the adipocyte-rich host organs are likely to be particularly affected by the presence of adipocytes. Although our understanding of how adipocytes influence tumour progression has grown significantly over the last several years, the mechanisms by which adipocytes regulate the metastatic niche are not well-understood. In this review, we focus on the omentum, a visceral white adipose tissue depot, and the bone, a depot for marrow adipose tissue, as two distinct adipocyte-rich organs that share common characteristic: they are both sites of significant metastatic growth. We highlight major differences in origin and function of each of these adipose depots and reveal potential common characteristics that make them environments that are attractive and conducive to secondary tumour growth. Special attention is given to how omental and marrow adipocytes modulate the tumour microenvironment by promoting angiogenesis, affecting immune cells and altering metabolism to support growth and survival of metastatic cancer cells.

Eribulin-induced liver dysfunction as a prognostic indicator of survival of metastatic breast cancer patients: a retrospective study

Background

Eribulin is a non-taxane, microtubule dynamics inhibitor that increases survival of patients with metastatic breast cancer. Although eribulin is well tolerated in patients with heavily pretreated disease, eribulin-induced liver dysfunction (EILD) can occur, resulting in treatment modification and subsequent poor disease control. We aimed to clarify the effect of EILD on patient survival.

Methods

The medical records of 157 metastatic breast cancer patients treated with eribulin between July 2011 and November 2013 at Cancer Institute Hospital were retrospectively analyzed. EILD was defined as 1) an increase in alanine aminotransferase or aspartate aminotransferase levels >3 times the upper limit of normal, and/or 2) initiation of a liver-supporting oral drug therapy such as ursodeoxycholic acid or glycyron. Fatty liver was defined as a decrease in the liver-to-spleen attenuation ratio to <0.9 on a computed tomography scan.

Results

EILD occurred in 42 patients, including one patient for whom eribulin treatment was discontinued due to severe EILD. The patients who developed EILD had significantly higher body mass indices (BMIs) than those who did not develop EILD (24.5 vs. 21.5, respectively; P < 0.0001), with no difference in the dose intensity of eribulin between the two groups (P = 0.76). Interestingly, the patients with EILD exhibited significantly longer progression-free survival (PFS) and overall survival (OS) than those without EILD (P = 0.010 and P = 0.032, respectively). Similarly, among 80 patients without liver metastasis, 19 with EILD exhibited significantly longer PFS and OS than the others (P = 0.0012 and P = 0.044, respectively), and EILD was an independent prognostic factor of PFS (P = 0.0079) in multivariate analysis. During eribulin treatment, 18 patients developed fatty liver, 11 of whom developed EILD, with a median BMI of 26.7.

Conclusions

Although EILD and fatty liver occurred at a relatively high frequency in our study, most of the patients did not experience severe adverse effects. Surprisingly, the development of EILD was positively associated with patient survival, especially in patients without liver metastases. EILD may be a clinically useful predictive biomarker of survival, but further studies are needed to confirm these findings in another cohort of patients.

Race, response to chemotherapy, and outcome within clinical breast cancer subtypes

The effect of race on breast cancer outcome is confounded by tumor and treatment heterogeneity. We examined a cohort of women with stage II-III breast cancer treated uniformly with neoadjuvant chemotherapy to identify factors associated with racial differences in chemotherapeutic response and long-term survival. Using a prospective database, we identified women with stage II-III breast cancer treated with neoadjuvant chemotherapy from 1998 to 2011. Race was categorized as African-American (AA) or non-AA. Preplanned subtype analyses were stratified by hormone receptor (HR) and HER2. Pathologic response to chemotherapy (pCR), time to recurrence (TTR), and overall survival (OS) were assessed using logistic regression, Kaplan-Meier method, and Cox proportional hazards regression analyses. Of 349 women identified, 102 (29 %) were AA, who were younger (p = 0.03), more obese (p < 0.001), and less likely to have HR+/HER2- tumors (p = 0.01). No significant differences in pCR rate by race were found. At median follow-up of 6.5 years, AA had worse TTR (hazard ratio 1.51, 95 % CI 1.02-2.24), which was attenuated in multivariable modeling, and there was no significant difference in OS. When stratified by HR, worse outcomes were limited to HR+AA (TTR hazard ratio 1.85, 95 % CI 1.09-3.14; OS hazard ratio 2.42 95 % CI 1.37-4.28), which remained significant in multivariable analysis including pCR rate and BMI. With long-term follow-up, racial disparity in outcome was limited to HR+ breast cancer, with no apparent contribution of chemotherapy sensitivity. This suggests that disparity root causes may be driven by HR+ factors such as unmeasured molecular differences, endocrine therapy sensitivity, or adherence.

Body mass index and survival in women with breast cancer-systematic literature review and meta-analysis of 82 follow-up studies

BACKGROUND

Positive association between obesity and survival after breast cancer was demonstrated in previous meta-analyses of published data, but only the results for the comparison of obese versus non-obese was summarised.

METHODS

We systematically searched in MEDLINE and EMBASE for follow-up studies of breast cancer survivors with body mass index (BMI) before and after diagnosis, and total and cause-specific mortality until June 2013, as part of the World Cancer Research Fund Continuous Update Project. Random-effects meta-analyses were conducted to explore the magnitude and the shape of the associations.

RESULTS

Eighty-two studies, including 213 075 breast cancer survivors with 41 477 deaths (23 182 from breast cancer) were identified. For BMI before diagnosis, compared with normal weight women, the summary relative risks (RRs) of total mortality were 1.41 [95% confidence interval (CI) 1.29-1.53] for obese (BMI >30.0), 1.07 (95 CI 1.02-1.12) for overweight (BMI 25.0-<30.0) and 1.10 (95% CI 0.92-1.31) for underweight (BMI <18.5) women. For obese women, the summary RRs were 1.75 (95% CI 1.26-2.41) for pre-menopausal and 1.34 (95% CI 1.18-1.53) for post-menopausal breast cancer. For each 5 kg/m(2) increment of BMI before, <12 months after, and ≥12 months after diagnosis, increased risks of 17%, 11%, and 8% for total mortality, and 18%, 14%, and 29% for breast cancer mortality were observed, respectively.

CONCLUSIONS

Obesity is associated with poorer overall and breast cancer survival in pre- and post-menopausal breast cancer, regardless of when BMI is ascertained. Being overweight is also related to a higher risk of mortality. Randomised clinical trials are needed to test interventions for weight loss and maintenance on survival in women with breast cancer.

The obesity-inflammation-eicosanoid axis in breast cancer

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

Connective tissue growth factor regulates adipocyte differentiation of mesenchymal stromal cells and facilitates leukemia bone marrow engraftment

Mesenchymal stromal cells (MSCs) are a major component of the leukemia bone marrow (BM) microenvironment. Connective tissue growth factor (CTGF) is highly expressed in MSCs, but its role in the BM stroma is unknown. Therefore, we knocked down (KD) CTGF expression in human BM-derived MSCs by CTGF short hairpin RNA. CTGF KD MSCs exhibited fivefold lower proliferation compared with control MSCs and had markedly fewer S-phase cells. CTGF KD MSCs differentiated into adipocytes at a sixfold higher rate than controls in vitro and in vivo. To study the effect of CTGF on engraftment of leukemia cells into BM, an in vivo model of humanized extramedullary BM (EXM-BM) was developed in NOD/SCID/IL-2rg(null) mice. Transplanted Nalm-6 or Molm-13 human leukemia cells engrafted at a threefold higher rate in adipocyte-rich CTGF KD MSC-derived EXM-BM than in control EXM-BM. Leptin was found to be highly expressed in CTGF KD EXM-BM and in BM samples of patients with acute myeloid and acute lymphoblastic leukemia, whereas it was not expressed in normal controls. Given the established role of the leptin receptor in leukemia cells, the data suggest an important role of CTGF in MSC differentiation into adipocytes and of leptin in homing and progression of leukemia.

Should visceral fat, strictly linked to hepatic steatosis, be depleted to improve survival?

Numerous epidemiologic studies have implicated abdominal obesity as a major risk factor for insulin resistance, type 2 diabetes mellitus, cardiovascular disease, stroke, metabolic syndrome and its further expression, i.e., nonalcoholic fatty liver disease and death. Using novel models of visceral obesity, several studies have demonstrated that the relationship between visceral fat and longevity is causal, while the accrual of subcutaneous fat does not appear to play an important role in the etiology of disease risk. The need of reducing the visceral fat to improve survival, mainly taking into account the strict link between nonalcoholic fatty liver disease and the coronary artery disease is discussed.

Breast tumor and stromal cell responses to TGF-β and hypoxia in matrix deposition

The components that comprise the extracellular matrix (ECM) are integral to normal tissue homeostasis as well as the development and progression of breast tumors. The secretion, construction, and remodeling of the ECM are each regulated by a complex interplay between tumor cells, fibroblasts and macrophages. Transforming growth factor-β (TGF-β) is an essential molecule in regulating the cellular production of ECM molecules and the adhesive interactions of cells with the ECM. Additionally, hypoxic cell signals, initiated by oxygen deprivation, additional metabolic factors or receptor activation, are associated with ECM formation and the progression of breast cancer. Both TGF-β and hypoxic cell signals are implicated in the functional and morphological changes of cancer-associated-fibroblasts and tumor-associated-macrophages. Moreover, the enhanced recruitment of tumor and stromal cells in response to hypoxia-induced chemokines leads to increased ECM deposition and remodeling, increased blood vessel formation, and enhanced tumor migration. Thus, elucidation of the collaborative networks between tumor and stromal cells in response to the combined signals of TGF-β and hypoxia may yield insight into treatment parameters that target both tumor and stromal cells.