The immunologic aspects in hormone receptor positive breast cancer

Breast cancer patient-derived scaffolds enhance the understanding of PD-L1 regulation and T cell cytotoxicity

Recent advances as well as obstacles for immune-based cancer treatment strategies, highlight the notable impact of patient cancer microenvironments on the immune cells and immune targets. Here, we use patient-derived scaffolds (PDS) generated from 110 primary breast cancers to monitor the impact of the cancer microenvironment on immune regulators. Pronounced variation in PD-L1 expression is observed in cancer cells adapted to different patient scaffolds. This variation is further linked to clinical observations and correlated with specific proteins detected in the cell-free PDSs using mass spectrometry. When adding T cells to the PDS-based cancer cultures, the killing efficiency of activated T cells vary between the cultures, whereas non-activated T cells modulate the cancer cell PD-L1 expression to treatment-predictive values, matching killing capacities of activated T cells. Surviving cancer cells show enrichment in cancer stem cell and epithelial-to-mesenchymal transition (EMT) features, suggesting that T cells may not efficiently target cells with metastatic potential. We conclude that clinically relevant insights in how to optimally target and guide immune-based cancer therapies can be obtained by including patient-derived scaffolds and cues from the cancer microenvironment in cancer patient handling and drug development.

Tumor Microenvironment Modulation by Tumor-Associated Macrophages: Implications for Neoadjuvant Chemotherapy Response in Breast Cancer

Background

Tumor-associated macrophages (TAMs) constitute an important part of the tumor microenvironment of breast cancer (BC), and they play an essential role in modulating tumor growth and invasion. However, the role of TAMs in neoadjuvant chemotherapy (NAC) has not been fully elucidated. Therefore, the aim of this study was to assess the function of TAM subtypes and investigate their role in the response to NAC in BC.

Methods

Presence of TAMs was examined immunohistochemically (IHC) in pre- and post- NAC treatment tumor tissue in a cohort of 138 BC patients. IHC staining with monoclonal antibodies for CD68 and CD163 were performed. Positivity was defined as staining > 1% TAMs in stroma and tumor cell nests. Response to NAC was evaluated according to tumor size change and Residual Cancer Burden (RCB) index.

Results

CD68+ and CD163+ TAMs decreased significantly in both the stroma and tumor nests (TN) after NAC. The median CD68+ TAMs in the stroma decreased significantly from 5% to 1% (p < 0.005), while CD163+ TAMs showed a marked reduction from 20% to 5% (p < 0.001). Post-NAC, the persistence of CD68+ and CD163+ TAMs in the stroma was strongly correlated with larger residual tumor size (p < 0.005 and p < 0.001, respectively). Changes in CD163+ TAM levels in the stroma were significantly associated with RCB classes (p < 0.005). Pre-NAC, CD163+ TAMs in the stroma and TN showed a significant association with TILs; however, no correlations with TILs were observed post-NAC.

Conclusion

This study highlights the critical role of TAMs dynamics in shaping NAC response in BC. Notably, CD163+ TAMs may emerge as pivotal players in mechanisms of chemotherapy resistance and response, underscoring their potential as biomarkers and therapeutic targets in breast cancer treatment.

Immunotherapy for hormone receptor‒positive HER2-negative breast cancer

Additional therapies are needed to improve outcomes in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative breast cancer. Research on the potential role of immunotherapy, particularly programmed cell death protein 1/programmed cell death ligand 1 inhibitors, is rapidly expanding in both the early and metastatic settings with some preliminary evidence suggesting benefit when used as part of combination therapy. Several ongoing phase 3 studies should help define their future role in treating these patients.

Current Immunotherapy Treatments of Primary Breast Cancer Subtypes

Breast cancer receives the most funding when compared to any other cancer type, according to a global study conducted by The Lancet. Nevertheless, this malignancy remains the most diagnosed cancer among women and relies heavily on a neoadjuvant treatment regimen of chemotherapy and targeted therapy. After standard treatment, 25-30% of breast cancer patients still develop disease recurrence and must undergo cytoreductive debulking surgery followed by intensive chemotherapy. An array of targeted therapies are currently being utilized and developed to alleviate negative side effects, eradicate cancer growth, and diminish disease recurrence. Immunotherapy is a promising cancer therapy that upregulates one's immune system to stimulate a therapeutic effect and is utilized for cancer management among other ailments such as immunodeficiencies, hypersensitivity reactions, autoimmune diseases, inflammatory disorders, tissue and organ transplantation, and infectious diseases. This review highlights the five primary subtypes of breast cancer, provides a brief history of immunotherapy, evaluates the current landscape of treating breast cancer with immunotherapy, analyzes selected ongoing or recently completed immunotherapy clinical trials for hormone receptor-positive, HER2-enriched, and triple-negative breast cancer, and examines future trends for the treatment of breast cancer with immunotherapeutic techniques. This review provides a formal summary categorized by breast cancer subtype rather than types of immunotherapeutic treatment.

Analyses of hypoxia-related risk factors and clinical relevance in breast cancer

Introduction

Hypoxia plays an important role in the heterogeneity, relapse, metastasis, and drug resistance of breast cancer. In this study, we explored the hypoxia-related biological signatures in different subtypes of breast cancer and identified the key prognostic factors by bioinformatics methods.

Methods

Based on The Cancer Genome Atlas (TCGA) Breast Cancer datasets, we divided the samples into immune-activated/suppressed populations by single-sample gene set enrichment analysis (ssGSEA) and then used hierarchical clustering to further identify hypoxic/non-hypoxic populations from the immune-suppressed samples. A hypoxia related risk model of breast cancer was constructed.

Results

Nuclear factor interleukin-3 regulated (NFIL3), serpin family E member 1 (SERPINE1), FOS, biglycan (BGN), epidermal growth factor receptor (EGFR), and sushi-repeat-containing protein, X-linked (SRPX) were identified as key hypoxia-related genes. Margin status, American Joint Committee on Cancer (AJCC) stage, hypoxia status, estrogen receptor/progesterone receptor (ER/PR) status, NFIL3, SERPINE1, EGFR, and risk score were identified as independent prognostic indicators for breast cancer patients. The 3- and 5-year survival curves of the model and immunohistochemical staining on the breast cancer microarray verified the statistical significance and feasibility of our model. Among the different molecular types of breast cancer, ER/PR+ and HER2+ patients might have higher hypoxia-related risk scores. ER/PR-negative samples demonstrated more activated immune-related pathways and better response to most anticancer agents.

Discussion

Our study revealed a novel risk model and potential feasible prognostic factors for breast cancer and might provide new perspectives for individual breast cancer treatment.

The immune microenvironment characterisation and dynamics in hormone receptor-positive breast cancer before and after neoadjuvant endocrine therapy

BACKGROUND

Oestrogen receptor positive (ER+)/HER-2 negative breast cancer (BC) is considered to be an immunologically cold tumour compared to triple negative breast cancer. Therefore, the tumour microenvironment (TME) of ER+/HER-2 negative BC is understudied. The aim of this project is to investigate the TME and the immune response during neoadjuvant endocrine therapy (NET) and to correlate this with the treatment response in a real life setting.

METHODS

Expression of immune checkpoint receptors and immune cells was examined immunohistochemically, pre- and post-NET in a cohort of 56 ER+/HER-2 negative BC patients. They were treated with tamoxifen (n = 16), an aromatase inhibitor (n = 40) or a combination of an aromatase inhibitor with a PI3K inhibitor (n = 11) for a median duration of 6 months (range 1-32 months). Immunohistochemical staining with monoclonal antibodies for PDL-1, PD-1, TIM-3, LAG-3, CTLA-4, CD4, CD68 and FOXP3 were performed. All staining procedures were done according to validated protocols, and scoring was done by a pathologist specialized in breast cancer. Positivity was defined as staining >1% on TILs. Response to NET was evaluated according to tumour size change on imaging and Ki-67 change.

RESULTS

The median age was 61.02 (37-90) years. Diameter of tumour size decreased with a mean of 8.1 mm (-16 mm to 45 mm) (p < 0.001) during NET and the value of Ki-67 value decreased with a median of 9 after NET (p < 0.001). An increase in PD-L1 expression after NET showed a trend towards significant (p = 0.088) and CD-4+ T cells significantly increased after NET (p = 0.03). A good response to NET defined as a decrease in tumour size and/or decrease of Ki-67 was found to be associated with a longer duration of NET, a change of CD4+ T-cells and a higher number of CD68+ tumour-associated macrophages before the start of NET.

CONCLUSION

The immune microenvironment plays an important role in ER+/HER-2 negative BC. NET influences the composition and functional state of the infiltrating immune cells. Furthermore, changes in the immune microenvironment are also associated with treatment response.

The Great Immune Escape: Understanding the Divergent Immune Response in Breast Cancer Subtypes

Breast cancer, the most common type of cancer affecting women, encompasses a collection of histologic (mainly ductal and lobular) and molecular subtypes exhibiting diverse clinical presentation, disease trajectories, treatment options, and outcomes. Immunotherapy has revolutionized treatment for some solid tumors but has shown limited promise for breast cancers. In this review, we summarize recent advances in our understanding of the complex interactions between tumor and immune cells in subtypes of breast cancer at the cellular and microenvironmental levels. We aim to provide a perspective on opportunities for future immunotherapy agents tailored to specific features of each subtype of breast cancer.

SIGNIFICANCE

Although there are currently over 200 ongoing clinical trials testing immunotherapeutics, such as immune-checkpoint blockade agents, these are largely restricted to the triple-negative and HER2+ subtypes and primarily focus on T cells. With the rapid expansion of new in vitro, in vivo, and clinical data, it is critical to identify and highlight the challenges and opportunities unique for each breast cancer subtype to drive the next generation of treatments that harness the immune system.

Current Molecular Combination Therapies Used for the Treatment of Breast Cancer

Breast cancer is the second leading cause of death for women worldwide. While monotherapy (single agent) treatments have been used for many years, they are not always effective, and many patients relapse after initial treatment. Moreover, in some patients the response to therapy becomes weaker, or resistance to monotherapy develops over time. This is especially problematic for metastatic breast cancer or triple-negative breast cancer. Recently, combination therapies (in which two or more drugs are used to target two or more pathways) have emerged as promising new treatment options. Combination therapies are often more effective than monotherapies and demonstrate lower levels of toxicity during long-term treatment. In this review, we provide a comprehensive overview of current combination therapies, including molecular-targeted therapy, hormone therapy, immunotherapy, and chemotherapy. We also describe the molecular basis of breast cancer and the various treatment options for different breast cancer subtypes. While combination therapies are promising, we also discuss some of the challenges. Despite these challenges, the use of innovative combination therapy holds great promise compared with traditional monotherapies. In addition, the use of multidisciplinary technologies (such as nanotechnology and computer technology) has the potential to optimize combination therapies even further.