Current Landscape: The Mechanism and Therapeutic Impact of Obesity for Breast Cancer

Comparing long-term prognosis following different surgical methods in patients with early stage breast cancer and obesity: a retrospective cohort study in China

OBJECTIVE

Breast-conserving therapy (BCT) includes breast-conserving surgery (BCS) combined with radiation therapy (RT). RT plays a crucial role in improving the prognosis of patients who undergo BCS. However, obesity is a potential risk factor for resistance to radiation. The aim of this study was to evaluate any difference in the long-term prognosis of patients with early stage breast cancer and obesity treated with BCT or total mastectomy (TM).

DESIGN, SETTING AND PARTICIPANTS

This was a retrospective cohort study involving 1125 patients diagnosed with early stage breast cancer and obesity at the Shanghai Cancer Center of Fudan University from 2013 to 2016.

OUTCOME MEASURES

Obesity in the Chinese population was defined as a body mass index ≥28 kg/m2. Surgical options included BCT and TM. The primary survival outcomes were overall survival (OS), disease-free survival (DFS) and recurrence-free survival (RFS). Inverse probability of treatment weighting (IPTW) was used to control for the impact of confounding factors on prognosis.

RESULTS

The median follow-up times in the BCT group and TM group without postoperative RT were 51.1 months (IQR of 40.6-68.1 months) and 61.8 months (IQR of 46.5-76.7 months), respectively. After IPTW, the baseline data were balanced. Compared with those in the TM cohort, patients in the whole IPTW cohort in the BCT cohort had worse DFS (HR 4.280, 95% CI 2.180 to 8.400; p<0.001), RFS (HR 4.380, 95% CI 2.370 to 8.120; p<0.001) and OS (HR 3.590, 95% CI 1.620 to 7.950; p=0.002).

CONCLUSION

In patients with early stage breast cancer and obesity, TM is associated with better survival outcomes than BCT.

In vitro and in silico evaluation of Andrographis paniculata ethanolic crude extracts on fatty acid synthase expression on breast cancer cells

Background

Fatty acid synthase (FASN), a key rate-limiting enzyme in the fatty acid biosynthesis pathway has been identified to be overexpressed in breast cancer. This overexpression has been affiliated with poor prognosis and resistance to chemotherapeutics. Consequently, FASN has come into focus as an appealing potential target for breast cancer treatment. Available FASN inhibitors, however, are unstable and have been correlated with adverse side effects.

Objective

This present study aims to investigate the potential of Andrographis paniculata ethanolic crude extract (AP) as a potent FASN inhibitor in breast cancer cells.

Materials & methods

This study used MTT assay and flow cytometry analysis to measure cell viability and apoptosis following AP treatment (0-500 μg/mL). Furthermore, FASN protein expression was evaluated using immunocytochemistry whereas lipid droplet formation was quantified using Oil Red O staining. Literature-based identified AP phytochemicals were subjected to the prediction of molecular docking and ADMET properties.

Results

This study demonstrated that AP significantly reduced cell viability while inducing apoptosis in breast cancer cells. In addition, for the first time, exposure to AP was demonstrated to drastically reduce intracellular FASN protein expression and lipid droplet accumulation in EMT6 and MCF-7 breast cancer cells. Docking simulation analysis demonstrated AP phytochemicals may have exerted an inhibitory effect by targeting the FASN Thioesterase (TE) domain similarly to the known FASN inhibitor, Orlistat. Moreover, all AP phytochemicals also possessed drug-likeness properties which are in accordance with Lipinski's rule of five.

Conclusions

These results highlight the potential of A. paniculata ethanolic crude extract as a FASN inhibitor and hence might have the potential to be further developed as a potent chemotherapeutic drug for breast cancer treatment.

Case report: An ultrasound-based approach as an easy tool to evaluate hormone receptor-positive HER-2-negative breast cancer in advanced/metastatic settings: preliminary data of the Plus-ENDO study

Background

Hormone receptor-positive tumors are unlikely to exhibit a complete pathological tumor response. The association of CDK 4/6 inhibitor plus hormone therapy has changed this perspective.

Case presentation

In this study, we retrospectively reviewed the charts of patients with a diagnosis of luminal A/B advanced/metastatic tumors treated with a CDK 4/6 inhibitor-based therapy. In this part of the study, we present clinical and ultrasound evaluation. Eight female patients were considered eligible for the study aims. Three complete and five partial responses were reported, including a clinical tumor response of 50% or more in five out of nine assessed lesions (55%). All patients showed a response on ultrasound. The mean lesion size measured by ultrasound was 27.1 ± 15.02 mm (range, 6-47 mm) at the baseline; 16.08 ± 14.6 mm (range, 0-40 mm) after 4 months (T1); and 11.7 ± 12.9 mm (range, 0-30 mm) at the 6 months follow-up (T2). Two patients underwent surgery. The radiological complete response found confirmation in a pathological complete response, while the partial response matched a moderate residual disease.

Conclusion

The evaluation of breast cancer by ultrasound is basically informative of response and may be an easy and practical tool to monitor advanced tumors, especially in advanced/unfit patients who are reluctant to invasive exams.

Impact of body mass index in therapeutic response for HER2 positive breast cancer treated with neoadjuvant targeted therapy: a multi-center study and meta-analysis

While overweight/obesity has become a major public health issue worldwide, any association between body mass index (BMI) and therapeutic response in neoadjuvant targeted therapy treated HER2 positive breast cancer patients remain unclear. The information from a total of four-hundred and ninety-one neoadjuvant targeted therapy treated HER2 positive breast cancer patients from four institutions were retrospectively collected. Univariate and multivariate logistic analysis was developed to determine the association between BMI and therapeutic response. A meta-analysis of published literature was then conducted to confirm the effect of overweight/obesity on pCR for patients treated with neoadjuvant targeted therapy. Restricted cubic spline (RCS) adjusted for confounding factors demonstrated a decrease pCR with increasing BMI (OR = 0.937, P = 0.045). Patients were then categorized into under/normal weight (n = 299) and overweight/obesity (n = 192). Overweight/obese patients were independently associated with a poor therapeutic response. In the subgroup analysis, a significant negative impact of overweight/obesity on pCR can be observed both in single-targeted (OR = 0.556; P = 0.02) and dual-targeted (OR = 0.392; P = 0.021) populations. Six eligible studies involving 984 neoadjuvant targeted therapy treated HER2 positive breast cancer patients were included in the meta-analysis. The meta-analysis also demonstrated that overweight/obesity was significantly associated with a poor response to neoadjuvant anti-HER2 therapy (OR = 0.68; P = 0.007). Our result show that overweight and obese HER2 positive breast cancer patients are less likely to achieve pCR after neoadjuvant targeted therapy.

Obesity promotes radioresistance through SERPINE1-mediated aggressiveness and DNA repair of triple-negative breast cancer

Obesity is a risk factor in various types of cancer, including breast cancer. The disturbance of adipose tissue in obesity highly correlates with cancer progression and resistance to standard treatments such as chemo- and radio-therapies. In this study, in a syngeneic mouse model of triple-negative breast cancer (TNBC), diet-induced obesity (DIO) not only promoted tumor growth, but also reduced tumor response to radiotherapy. Serpine1 (Pai-1) was elevated in the circulation of obese mice and was enriched within tumor microenvironment. In vitro co-culture of human white adipocytes-conditioned medium (hAd-CM) with TNBC cells potentiated the aggressive phenotypes and radioresistance of TNBC cells. Moreover, inhibition of both cancer cell autonomous and non-autonomous SERPINE1 by either genetic or pharmacological strategy markedly dampened the aggressive phenotypes and radioresistance of TNBC cells. Mechanistically, we uncovered a previously unrecognized role of SERPINE1 in DNA damage response. Ionizing radiation-induced DNA double-strand breaks (DSBs) increased the expression of SERPINE1 in cancer cells in an ATM/ATR-dependent manner, and promoted nuclear localization of SERPINE1 to facilitate DSB repair. By analyzing public clinical datasets, higher SERPINE1 expression in TNBC correlated with patients' BMI as well as poor outcomes. Elevated SERPINE1 expression and nuclear localization were also observed in radioresistant breast cancer cells. Collectively, we reveal a link between obesity and radioresistance in TNBC and identify SERPINE1 to be a crucial factor mediating obesity-associated tumor radioresistance.

Poor Muscle Status, Dietary Protein Intake, Exercise Levels, Quality of Life and Physical Function in Women with Metastatic Breast Cancer at Chemotherapy Commencement and during Follow-Up

This study aimed to investigate nutritional status, body composition, dietary protein intake, handgrip strength, 6 min or 4 m walk tests, self-reported physical activity, physical function, and quality of life (QoL-EORTC-QLQc30) at commencement of chemotherapy; to detect changes over time (from commencement of chemotherapy, and after 3, 6, 12, 26 and 52 weeks) in women with metastatic breast cancer (MBC); and to investigate the relationship between nutritional variables. 'Sarcopenia' was defined as low muscle mass and strength, 'myosteatosis' as muscle fat-infiltration (CT scan). Continuous variables were analysed using paired t-tests between baseline and follow-ups. Fifteen women (54y, 95% CI [46.3;61.2]) were recruited. At baseline, malnutrition was present in 3 (20%) participants, sarcopenia in 3 (20%) and myosteatosis in 7 (54%). Thirteen (87%) participants had low protein intake; low handgrip strength was observed in 0, and low walk test distance and physical activity in four (27%) participants. Physical function and QoL were low in 10 (67%) and 9 (60%), respectively. QoL between baseline and 52 weeks decreased by 11.7 (95% CI [2.4;20.9], p = 0.025). Other variables did not significantly change over time. In this small study sample, myosteatosis, low dietary protein intake, low exercise levels and impaired quality of life and physical function are common.

Fermented Black Tea and Its Relationship with Gut Microbiota and Obesity: A Mini Review

Fermentation is one of the world’s oldest techniques for food preservation, nutrient enhancement, and alcohol manufacturing. During fermentation, carbohydrates such as glucose and starch are converted into other molecules, such as alcohol and acid, anaerobically through enzymatic action while generating energy for the microorganism or cells involved. Black tea is among the most popular fermented beverages; it is made from the dried tea leaves of the evergreen shrub plant known as Camellia sinensis. The adequate consumption of black tea is beneficial to health as it contains high levels of flavanols, also known as catechins, which act as effective antioxidants and are responsible for protecting the body against the development of illnesses, such as inflammation, diabetes, hypertension, cancer, and obesity. The prevalence of obesity is a severe public health concern associated with the incidence of various serious diseases and is now increasing, including in Malaysia. Advances in ‘omic’ research have allowed researchers to identify the pivotal role of the gut microbiota in the development of obesity. This review explores fermented black tea and its correlation with the regulation of the gut microbiota and obesity.

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.

The obesity-breast cancer link: a multidisciplinary perspective

Obesity, exceptionally prevalent in the USA, promotes the incidence and progression of numerous cancer types including breast cancer. Complex, interacting metabolic and immune dysregulation marks the development of both breast cancer and obesity. Obesity promotes chronic low-grade inflammation, particularly in white adipose tissue, which drives immune dysfunction marked by increased pro-inflammatory cytokine production, alternative macrophage activation, and reduced T cell function. Breast tissue is predominantly composed of white adipose, and developing breast cancer readily and directly interacts with cells and signals from adipose remodeled by obesity. This review discusses the biological mechanisms through which obesity promotes breast cancer, the role of obesity in breast cancer health disparities, and dietary interventions to mitigate the adverse effects of obesity on breast cancer. We detail the intersection of obesity and breast cancer, with an emphasis on the shared and unique patterns of immune dysregulation in these disease processes. We have highlighted key areas of breast cancer biology exacerbated by obesity, including incidence, progression, and therapeutic response. We posit that interception of obesity-driven breast cancer will require interventions that limit protumor signaling from obese adipose tissue and that consider genetic, structural, and social determinants of the obesity–breast cancer link. Finally, we detail the evidence for various dietary interventions to offset obesity effects in clinical and preclinical studies of breast cancer. In light of the strong associations between obesity and breast cancer and the rising rates of obesity in many parts of the world, the development of effective, safe, well-tolerated, and equitable interventions to limit the burden of obesity on breast cancer are urgently needed.

Sarcopenic obesity in early breast cancer patients with metabolic syndrome: a cross-sectional study

Aim: The importance of sarcopenic obesity (SO) in malignancy has recently been recognized. The authors aimed to investigate the clinical and body composition data of early-stage breast cancer (BC) patients by focusing on the components of metabolic syndrome (MetS) and SO. Methods: In this cross-sectional study with early-stage BC patients, the clinical and laboratory results were evaluated for diagnosing MetS. Bioimpedance analysis and muscle radiation attenuation (Hounsfield unit average calculation [HUAC]) using acquired computed tomography images were used to assess SO. Results: The age at diagnosis, BMI, visceral fat ratio, hemoglobin A1c and carcinoembryonic antigen levels in patients with MetS were significantly higher (p < 0.05). A cutoff value of 39.4 Hounsfield units was significantly related to MetS with 76.5% sensitivity and 62% specificity. The mean HUAC in patients with MetS (36.9) was significantly lower than in those without MetS (41.4; p = 0.017). Conclusion: HUAC value predicted SO in early-stage BC patients with MetS.

Local Biomarkers Involved in the Interplay between Obesity and Breast Cancer

Simple Summary

Breast cancer is the second most common cancer in women worldwide. The risk of developing breast cancer depends on various mechanisms, such as age, heredity, reproductive factors, physical inactivity, and obesity. Obesity increases the risk of breast cancer and worsens outcomes for breast cancer patients. The rate of obesity is increasing worldwide, stressing the need for awareness of the association between obesity and breast cancer. In this review, we outline the biomarkers—including cellular and soluble factors—in the breast, associated with obesity, that affect the risk of breast cancer and breast cancer prognosis. Through these biomarkers, we aim to better identify patients with obesity with a higher risk of breast cancer and an inferior prognosis.

Abstract

Obesity is associated with an increased risk of breast cancer, which is the most common cancer in women worldwide (excluding non-melanoma skin cancer). Furthermore, breast cancer patients with obesity have an impaired prognosis. Adipose tissue is abundant in the breast. Therefore, breast cancer develops in an adipose-rich environment. During obesity, changes in the local environment in the breast occur which are associated with breast cancer. A shift towards a pro-inflammatory state is seen, resulting in altered levels of cytokines and immune cells. Levels of adipokines, such as leptin, adiponectin, and resistin, are changed. Aromatase activity rises, resulting in higher levels of potent estrogen in the breast. Lastly, remodeling of the extracellular matrix takes place. In this review, we address the current knowledge on the changes in the breast adipose tissue in obesity associated with breast cancer initiation and progression. We aim to identify obesity-associated biomarkers in the breast involved in the interplay between obesity and breast cancer. Hereby, we can improve identification of women with obesity with an increased risk of breast cancer and an impaired prognosis. Studies investigating mammary adipocytes and breast adipose tissue in women with obesity versus women without obesity are, however, sparse and further research is needed.

The Immune Landscape of Breast Cancer: Strategies for Overcoming Immunotherapy Resistance

Simple Summary

Immunotherapy is a rapidly advancing field in breast cancer treatment, however, it encounters many obstacles that leave open gateways for breast cancer cells to resist novel immunotherapies. It is believed that the tumor microenvironment consisting of cancer, stromal, and immune cells as well as a plethora of tumor-promoting soluble factors, is responsible for the failure of therapeutic strategies in cancer, including breast tumors. Therefore, an in-depth understanding of key barriers to effective immunotherapy, focusing the research efforts on harnessing the power of the immune system, and thus, developing new strategies to overcome the resistance may contribute significantly to increase breast cancer patient survival. In this review, we discuss the latest reports regarding the strategies rendering the immunosuppressive tumor microenvironment more sensitive to immunotherapy in breast cancers, HER2-positive and triple-negative types of breast cancer, which are attractive from an immunotherapeutic point of view.

Abstract

Breast cancer (BC) has traditionally been considered to be not inherently immunogenic and insufficiently represented by immune cell infiltrates. Therefore, for a long time, it was thought that the immunotherapies targeting this type of cancer and its microenvironment were not justified and would not bring benefits for breast cancer patients. Nevertheless, to date, a considerable number of reports have indicated tumor-infiltrating lymphocytes (TILs) as a prognostic and clinically relevant biomarker in breast cancer. A high TILs expression has been demonstrated in primary tumors, of both, HER2-positive BC and triple-negative (TNBC), of patients before treatment, as well as after treatment with adjuvant and neoadjuvant chemotherapy. Another milestone was reached in advanced TNBC immunotherapy with the help of the immune checkpoint inhibitors directed against the PD-L1 molecule. Although those findings, together with the recent developments in chimeric antigen receptor T cell therapies, show immense promise for significant advancements in breast cancer treatments, there are still various obstacles to the optimal activity of immunotherapeutics in BC treatment. Of these, the immunosuppressive tumor microenvironment constitutes a key barrier that greatly hinders the success of immunotherapies in the most aggressive types of breast cancer, HER2-positive and TNBC. Therefore, the improvement of the current and the demand for the development of new immunotherapeutic strategies is strongly warranted.

Results of the ECHO (Eating habits CHanges in Oncologic patients) Survey: An Italian Cross-Sectional Multicentric Study to Explore Dietary Changes and Dietary Supplement Use, in Breast Cancer Survivors

The role of a healthy diet in cancer prevention is well recognized. Recent data indicate that following the same advices can also improve cancer survivors’ quality of life. Breast cancer (BC) patients are commonly concerned about diet and nutrition and frequently express the need to obtain health-related information and the will to change their diet and lifestyle. Hence, be aware of survivors’ dietary changes and information needs is crucial for healthcare professionals to guide them toward optimal lifestyle choices. In order to investigate eating habits changes in a BC survivors’ population, we conceived the cross-sectional multicentric study ECHO (Eating habits CHanges in Oncologic patients) Survey. Data were collected from 684 patients, diagnosed with invasive breast cancer, in order to investigate their changes in food consumption, use of supplements, or the beginning of a specific diet, after BC diagnosis. We also examined the sources of information used and if any modification in their diets was reported to the oncologist. We primarily observed that patients increased their consumption of vegetables, pulses, nuts, fruits, wholemeal bread/pasta, grains and fish; while decreasing red and processed meat, refined bread/pasta, baked good and animal fat consumption. Survivors also reported the use of dietary supplements, mainly vitamins, aimed at counteracting therapies’ side effects. Changes in nutritional habits were often adopted without asking or informing the oncologist. Despite BC survivors made some positive changes in their nutritional habits, those modifications were mostly pursued by less than half of them, while the majority of patients consumed nutritional supplements after diagnosis. These results, as well as the failure to communicate with the physicians, reinforce the need to both improve the patient-healthcare professional relationship and to develop tailored nutrition counselling and intervention programs for cancer survivors.

Cancer Evo-Dev: A Theory of Inflammation-Induced Oncogenesis

Chronic inflammation is a prerequisite for the development of cancers. Here, we present the framework of a novel theory termed as Cancer Evolution-Development (Cancer Evo-Dev) based on the current understanding of inflammation-related carcinogenesis, especially hepatocarcinogenesis induced by chronic infection with hepatitis B virus. The interaction between genetic predispositions and environmental exposures, such as viral infection, maintains chronic non-resolving inflammation. Pollution, metabolic syndrome, physical inactivity, ageing, and adverse psychosocial exposure also increase the risk of cancer via inducing chronic low-grade smoldering inflammation. Under the microenvironment of non-resolving inflammation, pro-inflammatory factors facilitate the generation of somatic mutations and viral mutations by inducing the imbalance between the mutagenic forces such as cytidine deaminases and mutation-correcting forces including uracil-DNA glycosylase. Most cells with somatic mutations and mutated viruses are eliminated in survival competition. Only a small percentage of mutated cells survive, adapt to the hostile environment, retro-differentiate, and function as cancer-initiating cells via altering signaling pathways. These cancer-initiating cells acquire stem-ness, reprogram metabolic patterns, and affect the microenvironment. The carcinogenic process follows the law of "mutation-selection-adaptation". Chronic physical activity reduces the levels of inflammation via upregulating the activity and numbers of NK cells and lymphocytes and lengthening leukocyte telomere; downregulating proinflammatory cytokines including interleukin-6 and senescent lymphocytes especially in aged population. Anti-inflammation medication reduces the occurrence and recurrence of cancers. Targeting cancer stemness signaling pathways might lead to cancer eradication. Cancer Evo-Dev not only helps understand the mechanisms by which inflammation promotes the development of cancers, but also lays the foundation for effective prophylaxis and targeted therapy of various cancers.