Triple-Negative Breast Cancer: Basic Biology and Immuno-Oncolytic Viruses

Present and Future of Immunotherapy for Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) lacks the expression of estrogen receptors (ERs), human epidermal growth factor receptor 2 (HER2), and progesterone receptors (PRs). TNBC has the poorest prognosis among breast cancer subtypes and is more likely to respond to immunotherapy due to its higher expression of PD-L1 and a greater percentage of tumor-infiltrating lymphocytes. Immunotherapy has revolutionized TNBC treatment, especially with the FDA's approval of pembrolizumab (Keytruda) combined with chemotherapy for advanced cases, opening new avenues for treating this deadly disease. Although immunotherapy can significantly improve patient outcomes in a subset of patients, achieving the desired response rate for all remains an unmet clinical goal. Strategies that enhance responses to immune checkpoint blockade, including combining immunotherapy with chemotherapy, molecularly targeted therapy, or radiotherapy, may improve response rates and clinical outcomes. In this review, we provide a short background on TNBC and immunotherapy and explore the different types of immunotherapy strategies that are currently being evaluated in TNBC. Additionally, we review why combination strategies may be beneficial, provide an overview of the combination strategies, and discuss the novel immunotherapeutic opportunities that may be approved in the near future for TNBC.

New hopes for the breast cancer treatment: perspectives on the oncolytic virus therapy

Oncolytic virus (OV) therapy has emerged as a promising frontier in cancer treatment, especially for solid tumours. While immunotherapies like immune checkpoint inhibitors and CAR-T cells have demonstrated impressive results, their limitations in inducing complete tumour regression have spurred researchers to explore new approaches targeting tumours resistant to current immunotherapies. OVs, both natural and genetically engineered, selectively replicate within cancer cells, inducing their lysis while sparing normal tissues. Recent advancements in clinical research and genetic engineering have enabled the development of targeted viruses that modify the tumour microenvironment, triggering anti-tumour immune responses and exhibiting synergistic effects with other cancer therapies. Several OVs have been studied for breast cancer treatment, including adenovirus, protoparvovirus, vaccinia virus, reovirus, and herpes simplex virus type I (HSV-1). These viruses have been modified or engineered to enhance their tumour-selective replication, reduce toxicity, and improve oncolytic properties.Newer generations of OVs, such as Oncoviron and Delta-24-RGD adenovirus, exhibit heightened replication selectivity and enhanced anticancer effects, particularly in breast cancer models. Clinical trials have explored the efficacy and safety of various OVs in treating different cancers, including melanoma, nasopharyngeal carcinoma, head and neck cancer, and gynecologic malignancies. Notably, Talimogene laherparepvec (T-VEC) and Oncorine have. been approved for advanced melanoma and nasopharyngeal carcinoma, respectively. However, adverse effects have been reported in some cases, including flu-like symptoms and rare instances of severe complications such as fistula formation. Although no OV has been approved specifically for breast cancer treatment, ongoing preclinical clinical trials focus on four groups of viruses. While mild adverse effects like low-grade fever and nausea have been observed, the effectiveness of OV monotherapy in breast cancer remains insufficient. Combination strategies integrating OVs with chemotherapy, radiotherapy, or immunotherapy, show promise in improving therapeutic outcomes. Oncolytic virus therapy holds substantial potential in breast cancer treatment, demonstrating safety in trials. Multi-approach strategies combining OVs with conventional therapies exhibit more promising therapeutic effects than monotherapy, signalling a hopeful future for OV-based breast cancer treatments.

Magnetically induced self-assembly electrochemical biosensor with ultra-low detection limit and extended measuring range for sensitive detection of HER2 protein

An innovative electrochemical biosensor was fabricated for sensitive detection of human epidermal growth factor receptor 2 (HER2) protein, which was considered as an essential tumor marker for diagnosis and treatment evaluation of breast cancer. The sensor was constructed using Apt and PNA as recognition probes incorporated with magnetic Fe3O4/α-Fe2O3@Au nanocomposites. The sensing strategy was designed to lower the detection limit of HER2, and avoid the large steric interference caused by macromolecular HER2 on the electrode surface. Rigid structure dsDNA (Apt/ssDNA) was designed to improve the sensitivity of the sensor. Apt captured the macromolecular HER2 protein, and ssDNA chains were simultaneously released, causing a sensitive change in the electrochemical signal. PNA captured the released ssDNA chains, which converted the electrochemical signal changes caused by HER2 to those caused by the number of short strand ssDNA, so the detection range was extended. Under optimized conditions, this sensing strategy realized an ultra-low detection LOD of HER2 (4.1 fg·mL-1), and the detection range was 10 fg·mL-1-5 × 106 fg·mL-1. The experimental results confirmed that the electrochemical biosensor had excellent selectivity, reproducibility, and storage stability. Analysis of spiked serum samples exhibited a recovery rate of 95.9-115.7 %, which indicated great promise for HER2 detection in serum samples.

Tumor size is associated with adjuvant chemotherapy benefit in T1N0M0 triple-negative breast cancer: a multicenter and propensity score matched analysis

Background

Triple-negative breast cancer (TNBC) is characterized by aggressive phonotypes and relatively poor outcomes. There are controversies on the effect of adjuvant chemotherapy in small (T1N0M0) TNBCs, especially among T1a-b patients. This study evaluated the survival benefit of adjuvant chemotherapy and influential factors in T1N0M0 TNBC patients.

Methods

All T1N0M0 TNBC patients were identified from the Shanghai Jiao Tong University Breast Cancer Database (SJTU-BCDB) between January 2009 and December 2021. Propensity score matched (PSM) was applied to create a matched cohort. We used Kaplan-Meier analysis and Cox regression models to evaluate the associations of adjuvant chemotherapy with breast cancer-free interval (BCFI) and overall survival (OS). Stratified analysis according to different influential factors was also performed.

Results

In total, 1,113 T1N0M0 TNBC patients (297 T1a, T1b and 816 T1c) were enrolled, including 928 patients with adjuvant chemotherapy and 185 patients without adjuvant chemotherapy. After matching 441 patients by using PSM analysis, 294 patients with chemotherapy and 147 patients without chemotherapy were identified. Patients with or without chemotherapy had similar BCFI (P=0.241) and OS (P=0.509). However, regarding patients with different tumor sizes, adjuvant chemotherapy could significantly improve BCFI in T1c patients (5-year BCFI: 92.1% vs. 79.5%, P=0.035) but not in T1a-b patients (5-year BCFI: 93.6% vs. 94.6%, P=0.546). No significant difference in OS was observed among patients with different tumor sizes. Subgroup analysis found that only tumor size was significantly associated with adjuvant chemotherapy benefit in terms of BCFI (Pinteraction=0.021) and OS (Pinteraction=0.040).

Conclusions

The survival benefit of adjuvant chemotherapy was significantly associated with tumor size in T1N0M0 TNBC. Benefit of adjuvant chemotherapy was found in T1c, but not in T1a-b patients. Our findings do not support the routine use of chemotherapy in patients with T1a-bN0 TNBC.