The Role of Body Mass Index in Triple Negative Breast Cancer

Recent Advances in Drug Discovery for Triple-Negative Breast Cancer Treatment

Triple-negative breast cancer (TNBC) is one of the most heterogeneous and aggressive breast cancer subtypes with a high risk of death on recurrence. To date, TNBC is very difficult to treat due to the lack of an effective targeted therapy. However, recent advances in the molecular characterization of TNBC are encouraging the development of novel drugs and therapeutic combinations for its therapeutic management. In the present review, we will provide an overview of the currently available standard therapies and new emerging therapeutic strategies against TNBC, highlighting the promises that newly developed small molecules, repositioned drugs, and combination therapies have of improving treatment efficacy against these tumors.

A review of the impact of energy balance on triple-negative breast cancer

Cancer cells cannot proliferate without sufficient energy to generate biomass for rapid cell division, as well as to fuel their functions at baseline. For this reason, many recent observational and interventional studies have focused on increasing energy expenditure and/or reducing energy intake during and after cancer treatment. The impact of variance in diet composition and in exercise on cancer outcomes has been detailed extensively elsewhere and is not the primary focus of this review. Instead, in this translational, narrative review we examine studies of how energy balance impacts anticancer immune activation and outcomes in triple-negative breast cancer (TNBC). We discuss preclinical, clinical observational, and the few clinical interventional studies on energy balance in TNBC. We advocate for the implementation of clinical studies to examine how optimizing energy balance-through changes in diet and/or exercise-may optimize the response to immunotherapy in people with TNBC. It is our conviction that by taking a holistic approach that includes energy balance as a key factor to be considered during and after treatment, cancer care may be optimized, and the detrimental effects of cancer treatment and recovery on overall health may be minimized.

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.

Breast cancer growth and proliferation is suppressed by the mitochondrial targeted furazano[3,4-b]pyrazine BAM15

BACKGROUND

Enhanced metabolic plasticity and diversification of energy production is a hallmark of highly proliferative breast cancers. This contributes to poor pharmacotherapy efficacy, recurrence, and metastases. We have previously identified a mitochondrial-targeted furazano[3,4-b]pyrazine named BAM15 that selectively reduces bioenergetic coupling efficiency and is orally available. Here, we evaluated the antineoplastic properties of uncoupling oxidative phosphorylation from ATP production in breast cancer using BAM15.

METHODS

The anticancer effects of BAM15 were evaluated in human triple-negative MDA-MB-231 and murine luminal B, ERα-negative EO771 cells as well as in an orthotopic allograft model of highly proliferative mammary cancer in mice fed a standard or high fat diet (HFD). Untargeted transcriptomic profiling of MDA-MB-231 cells was conducted after 16-h exposure to BAM15. Additionally, oxidative phosphorylation and electron transfer capacity was determined in permeabilized cells and excised tumor homogenates after treatment with BAM15.

RESULTS

BAM15 increased proton leak and over time, diminished cell proliferation, migration, and ATP production in both MDA-MB-231 and EO771 cells. Additionally, BAM15 decreased mitochondrial membrane potential, while inducing apoptosis and reactive oxygen species accumulation in MDA-MB-231 and EO771 cells. Untargeted transcriptomic profiling of MDA-MB-231 cells further revealed inhibition of signatures associated with cell survival and energy production by BAM15. In lean mice, BAM15 lowered body weight independent of food intake and slowed tumor progression compared to vehicle-treated controls. In HFD mice, BAM15 reduced tumor growth relative to vehicle and calorie-restricted weight-matched controls mediated in part by impaired cell proliferation, mitochondrial respiratory function, and ATP production. LC-MS/MS profiling of plasma and tissues from BAM15-treated animals revealed distribution of BAM15 in adipose, liver, and tumor tissue with low abundance in skeletal muscle.

CONCLUSIONS

Collectively, these data indicate that mitochondrial uncoupling may be an effective strategy to limit proliferation of aggressive forms of breast cancer. More broadly, these findings highlight the metabolic vulnerabilities of highly proliferative breast cancers which may be leveraged in overcoming poor responsiveness to existing therapies.

Obesity and Energy Balance Considerations in Triple-Negative Breast Cancer

ABSTRACT

Obesity is an increasingly prevalent state of energy imbalance that contributes to breast cancer risk and outcomes. The effects of obesity differ by breast cancer subtype and menopause. While most studies have focused on postmenopausal hormone receptor-positive disease, less is known about the relationship between obesity and triple-negative breast cancer (TNBC). Here we will review the observations linking obesity to TNBC, the socioeconomic disparities that contribute to obesity-related TNBC, and putative biologic mechanisms. Finally, we will consider the impact of obesity on surgical and medical treatment of TNBC and novel strategies to improve energy balance after cancer diagnosis.

Assessing the prognostic factors, survival, and recurrence incidence of triple negative breast cancer patients, a single center study in Iran

Background

Breast cancer is the second leading cause of death due to cancer in women. Triple negative breast cancer (TNBC) is a subgroup with unique behavior. There is a controversy in organ involvement in metastasis. In this study, we planned to define the prognostic factors, survival, and recurrence incidence of patients.

Materials and method

Among the 583 patients with breast mass referred to hematology and oncology clinic in Shariati hospital, Tehran, Iran from March 2005 to March 2015, fifty four patients entered the survival analysis whom we followed for two years until March 2017. Overall survival (OS) and disease-free survival (DFS) and Cumulative recurrence incidences (RI) were estimated. Univariate and multivariate Cox proportional hazards regression was performed to assess risk factors in predicting OS and DFS.

Results

Median follow up for the patients was 5.00 years. The five-year OS, DFS and RI were 86.13% (95% CI (71.42–93.59), 63.09% (95% CI (47.04–75.49) and 32.15% (95% CI (19.52–47.43) respectively. Among the factors studied OS, DFS and RI differed significantly only between patients with and without nodal involvement (P = 0.004, P = 0.003, and P = 0.02 respectively). On the other hand, based on the univariate modeling, patients with nodal involvement had a higher risk of breast cancer-specific death (HR: 17.99, P = 0.004). Furthermore, patients with nodal involvement had a higher risk of breast cancer-specific death or recurrence (HR = 5.64, P = 0.008). In Multivariate model, just the nodal involvement significantly changed the hazard for OS (HR = 23.91, P = 0.001). As the nodal involvement was the only significant risk factor at the 0.2 level of significance, we can consider the hazard ratio of lymph node positivity in DFS univariate models as adjusted hazard.

Conclusion

The only factor with significant effect on OS, DFS and RI was nodal involvement in the pathology report.

Whole Genome Transcriptome Analysis of the Association between Obesity and Triple-Negative Breast Cancer in Caucasian Women

Background: Triple-negative breast cancer (TNBC) is the most aggressive form of breast cancer, with poor outcomes. The molecular basis of TNBC remains poorly understood. The objective of this exploratory study was to investigate the association between obesity and TNBC in premenopausal and postmenopausal Caucasian women using transcription profiling. Methods: We compared gene expression levels of tumor samples drawn from normal weight, overweight, and obese pre and postmenopausal women diagnosed with TNBC. We performed hierarchical clustering to assess similarity in patterns of gene expression profiles, and conducted network and pathway analysis to identify molecular networks and biological pathways. Results: We discovered gene signatures distinguishing normal weight from obese, normal weight from overweight, and overweight from obese individuals in both premenopausal and postmenopausal women. The analysis revealed molecular networks and biological pathways associating obesity with TNBC. The discovered pathways included the unfolded protein response, endoplasmic reticulum stress, B cell receptor, and autophagy signaling pathways in obese premenopausal women; and the integrin, axonal guidance, ERK/MAPK (extracellular-signal-regulated kinase/mitogen activated protein kinase) and glutathione biosynthesis signaling pathways in obese postmenopausal women. Conclusions: The results suggest that both overweight and obese status are associated with TNBC, highlighting the need for conformation of these results in independent studies.

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.

Triple-negative breast cancer and its association with obesity

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that lacks expression of the estrogen and progesterone receptor and does not overexpress human epidermal growth factor 2 receptor protein. TNBC is associated with special characteristics, including aggressiveness, poor prognosis and poor response to treatment, and has been attracting increasing attention worldwide. Obesity is a well-documented factor exerting a significant effect on the development of breast cancer, including TNBC. The purpose of the present review was to focus on the association between obesity and TNBC and provide a summary of novel research findings. The aim was to highlight the association between TNBC and obesity and provide an overview of novel outlooks on clinical issues, biological rationale, novel targeted therapies and prognosis, in order to draw attention to the significance of weight management, primary prevention, early diagnosis and treatment of this intractable disease.

Body mass index modifies the relationship between γ-H2AX, a DNA damage biomarker, and pathological complete response in triple-negative breast cancer

Background

Body mass index (BMI) is largely investigated as a prognostic and predictive factor in triple-negative breast cancer (TNBC). Overweight and obesity are linked to a variety of pathways regulating tumor-promoting functions, including the DNA damage response (DDR). The DDR physiologically safeguards genome integrity but, in a neoplastic background, it is aberrantly engaged and protects cancer cells from chemotherapy. We herein verified the role of BMI on a previously assessed association between DDR biomarkers and pathological complete response (pCR) in TNBC patients treated with neoadjuvant chemotherapy (NACT).

Methods

In this retrospective analysis 54 TNBC patients treated with NACT were included. The relationship between DDR biomarkers, namely phosphorylated H2A Histone Family Member X (γ-H2AX) and phosphorylated checkpoint kinase 1 (pChk1), and pCR was reconsidered in light of BMI data. The Pearson’s Chi-squared test of independence (2-tailed) and the Fisher Exact test were employed to assess the relationship between clinical-molecular variables and pCR. Uni- and multivariate logistic regression models were used to identify variables impacting pCR. Internal validation was carried out.

Results

We observed a significant association between elevated levels of the two DDR biomarkers and pCR in patients with BMI < 25 (p = 0.009 and p = 0.022 for γ-H2AX and pChk1, respectively), but not in their heavier counterpart. Results regarding γ-H2AX were confirmed in uni- and multivariate models and, again, for leaner patients only (γ-H2AX^high vs γ-H2AX^low: OR 10.83, 95% CI: 1.79–65.55, p = 0.009). The consistency of this finding was confirmed upon internal validation.

Conclusions

The predictive significance of γ-H2AX varies according to BMI status. Indeed, elevated levels of γ-H2AX seemed associated with lower pCR rate only in leaner patients, whereas differences in pCR rate according to γ-H2AX levels were not appreciable in heavier patients. Larger investigations are warranted concerning the potential role of BMI as effect modifier of the relationship between DDR-related biomarkers and clinical outcomes in TNBC.