Potential Value of HSP90α in Prognosis of Triple-Negative Breast Cancer

BACKGROUND Triple-negative breast cancer (TNBC) is a distinct subtype of breast cancer, accounting for 12-18% of all breast cancer cases. It exhibits high heterogeneity and aggressiveness, resulting in a poorer prognosis with a high risk of early recurrence and metastasis. Due to the lack of expression of estrogen receptors (ER), progesterone receptors (PR), and human epidermal growth factor receptor 2 (HER2), as well as insensitivity to endocrine therapy, determining a standard treatment for TNBC is challenging. The identification of potential prognostic biomarkers is crucial for developing personalized treatment strategies for patients. MATERIAL AND METHODS Our study investigated the potential value of HSP90a in TNBC prognosis. A retrospective analysis was conducted on 127 TNBC patients and 127 Healthy controls from March 1, 2019 to July 31, 2022. Venous blood was collected and tested for HSP90alpha, CEA, CA199, and CA125, and we recorded the clinical characteristics of the patients, including age, BMI, alcohol consumption status, surgical history, CEA level, CA199 level, CA125 level, HSP90alpha level, tumor size, distant metastases, lymph node metastasis, and TNM stage. Univariate and multivariate methods were used to screen independent risk factors for progression-free survival (PFS) and overall survival (OS). RESULTS HSP90alpha is not only upregulated in TNBC but is also highly correlated with lymph node metastasis and TNM stage. The results of multivariate analysis showed that distant metastasis, TNM stage and HSP90a level were independent factors associated with PFS. BMI, tumor size, TNM stage, surgical history, and HSP90a level were independent factors influencing OS. CONCLUSIONS Our research findings demonstrate a significant association between high HSP90alpha expression and adverse clinical features, suggesting a poorer prognosis for TNBC patients.

Promotion effect of FOXCUT as a microRNA sponge for miR-24-3p on progression in triple-negative breast cancer through the p38 MAPK signaling pathway

BACKGROUND

Triple-negative breast cancer (TNBC) is a type of highly invasive breast cancer with a poor prognosis. According to new research, long noncoding RNAs (lncRNAs) play a significant role in the progression of cancer. Although the role of lncRNAs in breast cancer has been well reported, few studies have focused on TNBC. This study aimed to explore the biological function and clinical significance of forkhead box C1 promoter upstream transcript (FOXCUT) in triple-negative breast cancer.

METHODS

Based on a bioinformatic analysis of the cancer genome atlas (TCGA) database, we detected that the lncRNA FOXCUT was overexpressed in TNBC tissues, which was further validated in an external cohort of tissues from the General Surgery Department of the First Affiliated Hospital of Nanjing Medical University. The functions of FOXCUT in proliferation, migration, and invasion were detected in vitro or in vivo. Luciferase assays and RNA immunoprecipitation (RIP) were performed to reveal that FOXCUT acted as a competitive endogenous RNA (ceRNA) for the microRNA miR-24-3p and consequently inhibited the degradation of p38.

RESULTS

lncRNA FOXCUT was markedly highly expressed in breast cancer, which was associated with poor prognosis in some cases. Knockdown of FOXCUT significantly inhibited cancer growth and metastasis in vitro or in vivo. Mechanistically, FOXCUT competitively bounded to miR-24-3p to prevent the degradation of p38, which might act as an oncogene in breast cancer.

CONCLUSION

Collectively, this research revealed a novel FOXCUT/miR-24-3p/p38 axis that affected breast cancer progression and suggested that the lncRNA FOXCUT could be a diagnostic marker and therapeutic target for breast cancer.

[Evaluation of PD-L1 expression and intratumoral lymphocytic infiltration in triple-negative invasive breast carcinoma]

INTRODUCTION

Triple negative breast cancer endophenotype (TNBC) is one of the least frequent and without therapeutic target; therefore we propose to study the correlation of PD-L1 immune checkpoint with the establishment of tumor microenvironment assessed by intratumoral stromal lymphocyte infiltration (TILS) and its importance in clinical practice.

METHODS

A retrospective case-control study was performed, with 31 cases of triple-negative infiltrating breast carcinoma and 57 unmatched controls of Luminal A, Luminal B and HER-2 endophenotype seen in one year. The following variables were evaluated: histologic type and grade, PD-L1 expression with clone 22C3, TILS, lymphovascular invasion, tumor size, lymph node involvement and metastasis. Statistical analysis was performed with the chi-square test and Spearman correlation coefficient test.

RESULTS

a statistically significant negative correlation was found between TILS and PD-L1 (rho - 0.106, p 0.025), indicating that the higher the expression of PD-L1, the lower the intratumoral lymphocytic infiltration. In the TILS B (10-40% TILS) and C (40-90% TILS) groups where there was a marked intratumoral inflammatory infiltrate, a greater number of patients were negative for PD-L1 (CPS <10) with 16 and 10 cases, respectively. For TNBC cases a negative association coefficient was identified (rho -0.378) with statistical significance (p 0.01).

DISCUSSION

The association between TNBC, TILS and PDL1 expression was established, which is important for the establishment of target therapies and the development of precision medicine.

Risk factors and survival of triple-negative breast cancer among breast cancer patients: Ten-year cross-sectional study in the southwestern Iranian population

Background

Breast cancer results from genetic and epigenetic mutations, contributing significantly to cancer-related morbidity and mortality. This study aimed to determine the prevalence and survival rates of triple-negative breast cancer (TNBC) among breast cancer patients in southwestern Iran over a ten-year period.

Methods

This retrospective cross-sectional study aims to assess prognostic factors associated with survival in women diagnosed with breast cancer in Iran's southwestern region over a ten-year period (2007-2017). Data were collected from patients who visited the Clinical Oncology Department at Golestan Hospital in Ahvaz (the breast cancer center of the Southwestern country). The study enrolled women diagnosed with TNBC using a census method and data from medical records. The primary outcome (survival rates) and secondary outcomes (demographic data, diagnostic stages, and three receptors estrogen receptors [ER], progesterone receptor [PR], human epidermal growth factor receptor 2 [HER2] status) were collected.

Results

Breast cancer was diagnosed in 2641 women over ten years; TNBC was diagnosed in 227 individuals (8.59%). Statistical analysis revealed a significant correlation between negative ER status and TNBC (p > 0.05). Furthermore, the prevalence of TNBC differed significantly from that of other types of breast cancer (p = 0.0001). The variables of age, HER2, PR, and TNBC grade did not differ significantly (p > 0.05). The overall disease-free survival rate over 5 years was 88.1%, while the rate for individuals without recurrence was 77.97%.

Conclusion

This study highlights a differentially low incidence of TNBC in the southwestern part of Iran when compared to other regions; genetic or epigenetic influences may explain this discrepancy. ER-negative status is a crucial prognostic indicator in diagnosing TNBC. The incidence of this disease is expected to rise by 100% in 2 years and 77.97% in 5 years.

Real-world data on triple-negative breast cancer in Latin America and the Caribbean

Breast cancer (BC) is the most prevalent cancer in women in Latin America and the Caribbean. We compiled real-world data (RWD) on the epidemiology, diagnosis, treatment, and patient outcomes of triple-negative breast cancer (TNBC), addressing the main barriers to optimal care in Latin America. The prevalence of TNBC varies between 11% and 38.5% of all BC cases diagnosed in the region, and TNBC primarily affects young patients. Delays in BC diagnosis, with consequent advanced disease stages and barriers to access efficient therapies, particularly due to high costs, negatively impact patient outcomes. Cancer clinical trials are an opportunity to access standard and novel therapies for patients with this aggressive BC subtype and thus must be prioritised. Finally, generating RWD and cost-effectiveness studies in a region with limited resources is critical for decision-makers to define the incorporation of new technologies for the treatment of BC.

Multiple suppressing small interfering RNA for cancer treatment-Application to triple-negative breast cancer

Certain cancers, such as triple-negative breast cancer (TNBC), pose a challenging prognosis due to the absence of identifiable hormone-related receptors and effective targeted therapies. Consequently, novel therapeutics are required for these cancers, offering minimal side effects and reduced drug resistance. Unexpectedly, siRNA-7, initially employed as a control, exhibited significant efficacy in inhibiting cell viability in MDA-MB-231 cells. Through a genome-wide search of seed sequences, the targets of siRNA-7 were identified as cancer-related genes, namely PRKCE, RBPJ, ZNF737, and CDC7 in MDA-MB-231 cells. The mRNA repression analysis confirmed the simultaneous suppression by siRNA-7. Combinatorial administration of single-targeting siRNAs demonstrated a comparable reduction in viability to that achieved by siRNA-7. Importantly, siRNA-7 selectively inhibited cell viability in MDA-MB-231 cells, while normal HDF-n cells remained unaffected. Furthermore, in a xenograft mouse model, siRNA-7 exhibited a remarkable 76% reduction in tumor volume without any loss in body weight. These findings position siRNA-7 as a promising candidate for a novel, safe, specific, and potent TNBC cancer therapeutic. Moreover, the strategy of multiple suppressing small interfering RNA holds potential for the treatment of various diseases associated with gene overexpression.

Pingxiao capsule inhibits lung metastasis of triple-negative breast cancer and sensitizes breast cancer to radiotherapy

OBJECTIVES

To investigate the anticancer effect of Pingxiao capsule (, PXC) on the treatment of breast cancer and .

METHODS

The inhibition of PXC on cell viability and proliferation was determined by cell counting kit-8, EdU assay and colony formation assay, respectively. The effect of PXC on cell apoptosis was detected by using flow cytometry. The suppression of PXC on cell migration and invasion was investigated by chamber assay. To investigate the underlying molecular mechanisms, the expression of proteins related to epithelial to mesenchymal transition (EMT) was analyzed by Western blotting in breast cancer cells and by immunohistochemistry in tumor tissues. The anticancer effect of PXC was evaluated by using MDA-MB-231 xenograft model and 4T1 metastatic breast cancer model.

RESULTS

Our results indicated that triple-negative breast cancer (TNBC) cell lines MDA-MB-231 and MDA-MB-468 were sensitive to PXC. PXC potently inhibited the proliferation, colony formation, migration, and invasion of MDA-MB-231 and MDA-MB-468 cells . Then, MDA-MB-231 xenograft model depicted that PXC significantly reduced tumor size and weight compared with Control. 4T1 lung metastasis model showed that PXC significantly inhibited breast cancer cell spreading to lungs in mice. Mechanistically, PXC inhibited EMT process by reducing cadherin turnover in TNBC. Furthermore, PXC in combination with 8 Gy X-ray treatment obviously promoted the induction of apoptosis, and suppressed cell proliferation.

CONCLUSION

PXC could inhibit the proliferation and invasion of TNBC both and , and exerted its anti-metastatic effect by regulating cadherin turnover, Furthermore, it sensitized the TNBC cells to radiotherapy. The data supported further development of PXC as an adjuvant-therapy agent for TNBC.

Tall cell carcinoma with reversed polarity of breast: Sonographic and magnetic resonance imaging findings

Tall cell carcinoma with reversed polarity (TCCRP) of breast is a rare subtype of breast cancer, which show tall and columnar cells with nuclei of reversed polarity, resembles tall cell variant in papillary thyroid cancer. Only 78 cases in 20 published studies had been reported by 2021. TCCRP was recently included as a separate subgroup of rare tumors in the World Health Organization Blue Book Classification of breast tumors (5th edition). We describe a TCCRP case in a 64-year-old woman with detailed radiologic features including quantitative ultrasonography.

Inhibition of MYC suppresses programmed cell death ligand-1 expression and enhances immunotherapy in triple-negative breast cancer

BACKGROUND

Cancer immunotherapy has emerged as a promising strategy against triple-negative breast cancer (TNBC). One of the immunosuppressive pathways involves programmed cell death-1 (PD-1) and programmed cell death ligand-1 (PD-L1), but many patients derived little benefit from PD-1/PD-L1 checkpoint blockades treatment. Prior research has shown that MYC, a master transcription amplifier highly expressed in TNBC cells, can regulate the tumor immune microenvironment and constrain the efficacy of immunotherapy. This study aims to investigate the regulatory relationship between MYC and PD-L1, and whether a cyclin-dependent kinase (CDK) inhibitor that inhibits MYC expression in combination with anti-PD-L1 antibodies can enhance the response to immunotherapy.

METHODS

Public databases and TNBC tissue microarrays were used to study the correlation between MYC and PD-L1. The expression of MYC and PD-L1 in TNBCs was examined by quantitative real-time polymerase chain reaction and Western blotting. A patient-derived tumor xenograft (PDTX) model was used to evaluate the influence of a CDK7 inhibitor THZ1 on PD-L1 expression. Cell proliferation and migration were detected by 5-ethynyl-2'-deoxyuridine (EdU) cell proliferation and cell migration assays. Tumor xenograft models were established for in vivo verification.

RESULTS

A high MYC expression level was associated with a poor prognosis and could alter the proportion of tumor-infiltrating immune cells (TIICs). The positive correlation between MYC and PD-L1 was confirmed by immunostaining samples from 165 TNBC patients. Suppression of MYC in TNBC caused a reduction in the levels of both PD-L1 messenger RNA and protein. In addition, antitumor immune response was enhanced in the TNBC cancer xenograft mouse model with suppression of MYC by CDK7 inhibitor THZ1.

CONCLUSIONS

The combined therapy of CDK7 inhibitor THZ1 and anti-PD-L1 antibody appeared to have a synergistic effect, which might offer new insight for enhancing immunotherapy in TNBC.

Molecular Characterization of BRCA1 c.5339T>C Missense Mutation in DNA Damage Response of Triple-Negative Breast Cancer

BRCA1 L1780P BRCT domain mutation has been recognized as a pathogenic mutation in patients with breast cancer. However, the molecular significance of this mutation has not yet been studied in triple-negative breast cancer (TNBC) cells in vitro. We established MDA-MB 231, HCC1937, and HCC1395 TNBC cell lines expressing BRCA1 L1780P mutant. BRCA1 L1780P mutant TNBC cells showed increased migration and invasion capacity, as well as increased sensitivity to olaparib and carboplatin compared to BRCA1 wild-type cells. BRCA1 L1780P mutant TNBC cells showed decreased RAD51 expression and reduced nuclear RAD51 foci formation following carboplatin and olaparib treatment. The molecular interaction between p-ATM and BRCA1 was abrogated following introduction of BRCA1 L1780P mutant plasmid in TNBC cells, suggesting that the BRCA1 L1780P mutation disrupts the p-ATM-BRCA1 protein-protein interaction. We established an olaparib-resistant BRCA1 L1780P mutant TNBC cell line by chronic drug treatment. Olaparib-resistant cell lines showed upregulation of RAD51 expression upon olaparib treatment, and reduction in RAD51 expression in olaparib-resistant cells restored olaparib sensitivity. Collectively, these results suggest that the BRCA1 L1780P mutation impairs RAD51 recruitment by disrupting p-ATM-BRCA1 interaction, which is a crucial molecular factor in homologous recombination and olaparib sensitivity. Further therapeutic targeting of RAD51 in BRCA1 L1780P mutant breast cancer is warranted.

Triple Negative Breast Cancer: Updates on Classification and Treatment in 2021

Simple Summary

Triple negative breast cancer (TNBC) represents 15 to 20% of all breast cancers in the United States. The main treatment option remains chemotherapy, despite limited efficacy. New biologic and targeted agents are increasingly emerging for the treatment of TNBC. Given the continuous advances in the field of TNBC, this review assesses the latest developments in basic characterization, subtyping, and treatment of TNBC, including novel drug developments with antibody-drug conjugates, immune checkpoint inhibitors, PARP inhibitors, and androgen receptor targeted agents.

Abstract

Breast cancer (BC) is the most common malignancy affecting women. It is a highly heterogeneous disease broadly defined by the differential expression of cell surface receptors. In the United States, triple negative breast cancer (TNBC) represents 15 to 20% of all BC. When compared with other subtypes of BC, TNBC tends to present in younger women, and has a higher mortality rate of 40% in advanced stages within the first 5 years after diagnosis. TNBC has historically had limited treatment options when compared to other types of BC. The mainstay of treatment for TNBC remains cytotoxic chemotherapy despite the emergence of new biologic and targeted agents. Defining the specific tumor molecular profile including PDL-1 and androgen receptor testing is expanding treatment options in the clinical setting. Identifying more targetable, novel biomarkers that may better define therapeutic targets or prognostic markers is currently underway. TNBC nomenclature is expected to be updated in favor of other nomenclature which would help direct therapy, and further redefine TNBC’s heterogeneity. Given the continuous advances in the field of TNBC, this review assesses the latest developments in basic characterization, subtyping, and treatment of TNBC, including novel drug developments with antibody-drug conjugates, immune checkpoint inhibitors, PARP inhibitors and androgen receptor targeted agents. Future trials are necessary in the face of these innovations to further support the use of new therapies in TNBC and the detection of the appropriate biomarkers.

Tall Cell Carcinoma With Reversed Polarity of the Breast

Tall cell carcinoma with reversed polarity (TCCRP) of the breast is a rare entity with low potential for malignancy that exhibits some morphological similarities to the tall cell variant of papillary thyroid carcinoma. Immunohistochemical and molecular studies help establish the mammary origin of this neoplasm. Here, we describe the case of a 63-year-old woman with a finding of a nodular lesion during a screening mammogram, whose morphological findings and immunohistochemical studies confirmed the diagnosis of papillary high cell carcinoma with the reverse polarity of the mammary gland.

Healthcare use and costs in early breast cancer: a patient-level data analysis according to stage and breast cancer subtype

Background

The cost of breast cancer care rises with higher stage at diagnosis; however, there are no real-world data regarding the cost of care according to breast cancer subtypes. This study aimed to estimate direct medical costs for early breast cancer care in the first 3 years after diagnosis according to subtype and stage, using patient-level data.

Methods

Women with newly diagnosed stage I–III breast cancer, admitted in 2012 to a Portuguese cancer centre were prospectively followed within the NEON-BC cohort. The use of health resources was obtained from each patient’s clinical and administrative records and costs were computed. Tumours were classified into the classic subtypes (hormone receptor-positive (HR+)/HER2−; HER2-positive (HER2+); triple-negative breast cancer (TNBC)) and surrogate intrinsic subtypes (luminal A-like; luminal B-like; HER2 enriched; basal like).

Results

A total of 703 patients were included: 48.9% had stage I, 35.8% stage II and 15.2% stage III breast cancer; 76.4% had HR+/HER2−, 15.9% HER2+ and 7.7% TNBC. Median cost of care was €9215/patient in stage I, €13 019/patient in stage II and €15 011/patient in stage III and €10 540/patient in HR+/HER2−, €11 224/patient in TNBC and €41 513/patient in HER2+ breast cancer. Systemic therapy accounted for 69.2% of the cost of care among patients with HER2+, 12.0% among HR+/HER2− and 7.5% among TNBC patients. Similar differences were observed across surrogate intrinsic subtypes.

Conclusions

The cost of early breast cancer care was mainly driven by the tumour subtype and, to a lesser extent, by stage. The median cost of care was fourfold higher among patients with HER2+ tumours compared with those with HR+/HER2− and TNBC. These data provide information for the economic evaluation of innovative treatments for early breast cancer and highlight the weight that targeted systemic therapy might have in the overall cost of care among patients with early breast cancer.

Dual inhibition of MEK1/2 and MEK5 suppresses the EMT/migration axis in triple-negative breast cancer through FRA-1 regulation

Triple-negative breast cancer (TNBC) presents a clinical challenge due to the aggressive nature of the disease and a lack of targeted therapies. Constitutive activation of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway has been linked to chemoresistance and metastatic progression through distinct mechanisms, including activation of epithelial-to-mesenchymal transition (EMT) when cells adopt a motile and invasive phenotype through loss of epithelial markers (CDH1), and acquisition of mesenchymal markers (VIM, CDH2). Although MAPK/ERK1/2 kinase inhibitors (MEKi) are useful antitumor agents in a clinical setting, including the Food and Drug Administration (FDA)-approved MEK1,2 dual inhibitors cobimetinib and trametinib, there are limitations to their clinical utility, primarily adaptation of the BRAF pathway and ocular toxicities. The MEK5 (HGNC: MAP2K5) pathway has important roles in metastatic progression of various cancer types, including those of the prostate, colon, bone and breast, and elevated levels of ERK5 expression in breast carcinomas are linked to a worse prognoses in TNBC patients. The purpose of this study is to explore MEK5 regulation of the EMT axis and to evaluate a novel pan-MEK inhibitor on clinically aggressive TNBC cells. Our results show a distinction between the MEK1/2 and MEK5 cascades in maintenance of the mesenchymal phenotype, suggesting that the MEK5 pathway may be necessary and sufficient in EMT regulation while MEK1/2 signaling further sustains the mesenchymal state of TNBC cells. Furthermore, additive effects on MET induction are evident through the inhibition of both MEK1/2 and MEK5. Taken together, these data demonstrate the need for a better understanding of the individual roles of MEK1/2 and MEK5 signaling in breast cancer and provide a rationale for the combined targeting of these pathways to circumvent compensatory signaling and subsequent therapeutic resistance.

A PD-L1 Aptamer Selected by Loss-Gain Cell-SELEX Conjugated with Paclitaxel for Treating Triple-Negative Breast Cancer

BACKGROUND The clinical challenges of triple-negative breast cancer (TNBC) includes the lack of targeted therapy and chemoresistance. TNBC has relatively high PD-L1 expression, and PD-L1 antibody in combination with nab-paclitaxel has been approved by FDA for TNBC treatment. Aptamers, also termed chemical antibody, are widely used in targeted drug delivery. The present study aimed to select a DNA aptamer that could specifically bind and deliver drugs to TNBC cells. MATERIAL AND METHODS An innovative loss-gain cell-SELEX strategy was used to select DNA aptamer for PD-L1 protein. Construction of PD-L1 knock-out and over-expression MDA-MB-231 cell lines were conducted through transfection and confirmed by western blot and flow cytometry. Confocal microscopy and flow cytometry were used to analyze the binding ability of aptamer with TNBC cells. The cytotoxicity of aptamer-paclitaxel complex against TNBC cells was evaluated by Cell Counting Kit-8 assay. The reactivation of the T cell function by aptamer was measured by IL-2 enzyme-linked immunosorbent assay after T cells co-cultured with tumor cells. RESULTS In this work, using an innovative loss-gain cell-SELEX strategy, we screened a PD-L1-targeting aptamer. PD-L1 aptamer selectively bound to PD-L1 over-expressed TNBC cells with a dissociation constant in the nanomolar range. PD-L1 aptamer could also inhibit PD-1/PD-L1 interaction and restore the function of T cells. Moreover, we developed a PD-L1 aptamer-paclitaxel conjugate which showed improved cellular uptake and anti-proliferation efficacy in PD-L1 over-expressed TNBC cells. CONCLUSIONS In summary, these findings suggest that the selected PD-L1 aptamer might have potential implication in immune modulation and targeted therapy against TNBC.

Effect of Clinical and Treatment Factors on Survival Outcomes of Triple Negative Breast Cancer Patients

Purpose

Triple negative breast cancer (TNBC) accounts for approximately 15% of breast cancer cases and is associated with a poor prognosis. In this retrospective study of patients undergoing radiation therapy as part of their treatment, disease-free survival (DFS) and overall survival (OS) of TNBC patients were examined in relation to clinical and treatment-related factors.

Patients and Methods

The electronic records of 214 consecutive TNBC patients treated with surgery followed by radiotherapy at the Mid North Coast Cancer Institute between 2006 and 2016 were reviewed. Overall survival and DFS times were analyzed using the Kaplan-Meier method; multivariate Cox proportional hazard regression modelling was used to assess the significance of prognostic factors.

Results

The majority of tumors were T1 (51.9%), followed by T2 (39.2%) and T3 (6.1%). For the whole group, mean DFS was 106.4 (SD 48.7) months; OS 109.4 (SD 52.1) months. Radiotherapy technique, fractionation protocol and laterality were not significant factors for DFS or OS (p>0.05). However, compared to breast conservation, mastectomy was associated with poorer DFS (mean 114.2 vs 65.2 months; p<0.0001) and poorer OS (mean 115.5 vs 80.5 months; p=0.0015). The mastectomy group had fewer patients with tumor size T1 (p=0.001) and higher proportions of T3 (p=0.001) and T4 (p=0.02). On multivariate analysis, tumor size T3/T4 and nodal status N2/N3 were significant factors for reduced DFS (p=0.023 and p=0.0003 respectively). Tumor size T3/T4 was the only significant prognostic factor for reduced OS (p=0.019).

Conclusion

Advanced disease exhibited by tumor size > 5cm and positive nodal status is associated with poorer DFS in TNBC patients. Radiotherapy technique or fractionation protocol were not associated with differences in DFS or OS in our patient cohort.

BET proteins regulate homologous recombination-mediated DNA repair: BRCAness and implications for cancer therapy

Bromodomain and Extra-Terminal (BET) proteins are historically involved in regulating gene expression and BRD4 was recently found to be involved in DNA damage regulation. Aims of our study were to assess BRD4 regulation in homologous recombination-mediated DNA repair and to explore novel clinical strategies through the combinations of the pharmacological induction of epigenetic BRCAness in BRCA1 wild-type triple negative breast cancer (TNBC) cells by means of BET inhibitors and compounds already available in clinic. Performing a dual approach (chromatin immunoprecipitation and RNA interference), the direct relationship between BRD4 and BRCA1/RAD51 expression was confirmed in TNBC cells. Moreover, BRD4 pharmacological inhibition using two BET inhibitors (JQ1 and GSK525762A) induced a dose-dependent reduction in BRCA1 and RAD51 levels and is able to hinder homologous recombination-mediated DNA damage repair, generating a BRCAness phenotype in TNBC cells. Furthermore, BET inhibition impaired the ability of TNBC cells to overcome the increase in DNA damage after platinum salts (i.e., CDDP) exposure, leading to massive cell death, and triggered synthetic lethality when combined with PARP inhibitors (i.e., AZD2281). Altogether, the present study confirms that BET proteins directly regulate the homologous recombination pathway and their inhibition induced a BRCAness phenotype in BRCA1 wild-type TNBC cells. Noteworthy, being this strategy based on drugs already available for human use, it is rapidly transferable and could potentially enable clinicians to exploit platinum salts and PARP inhibitors-based treatments in a wider population of TNBC patients and not just in a specific subgroup, after validating clinical trials.

Plasma 3,3',5-Triiodo-L-thyronine [T3] level mirrors changes in tumor markers in two cases of metastatic cancer of the breast and pancreas treated with exogenous L-T3

Preclinical studies have attributed 3,3’,5-triiodo-L-thyronine (T3) a direct negative effect on tumor progression, as well as chemosensitizing, differentiating and immunomodulatory properties. On the other hand, L-thyroxine (T4), via a thyroid hormone receptor on plasma membrane integrin αvβ3, promotes solid tumor growth and neoangiogenesis, therefore lowering endogenous T4 reduces tumor growth rate. We present the case of two patients with metastatic triple negative breast cancer and metastatic pancreatic cancer respectively, who benefit of the sole treatment with antithyroid drugs and exogenous administration of T3 (liothyronine). In these cases tumor growth was accompanied by T3 depletion in plasma, which may represent a novel marker for progression.

Prognostic and predictive factors of eribulin efficacy in heavily pretreated patients affected by metastatic breast cancer: correlation with tumor biology and previous therapies

Background

Eribulin mesylate is currently approved in the United States and Europe for the treatment of metastatic breast cancer (MBC).

Scope

The objective of this retrospective study is to find specific predictive criteria related to patient or tumor characteristics in order to select patients that might benefit the most from eribulin and define the correct treatment sequence.

Findings

Forty-four patients with MBC who received eribulin in third or subsequent lines of therapy in a single Italian center were considered eligible. Patients were stratified by body mass index, hormonal/HER2 status, and previous therapies. Primary endpoint was progression free survival (PFS), whereas secondary endpoint was disease control rate (DCR).

A longer PFS was found in patients with hormone-positive tumors (p=0.0051), in HER2-negative cases (p=0.037), and in overweight patients (p=0.0015). No difference in efficacy was observed when eribulin was administered in third or subsequent lines of therapy. Significantly longer PFS (p<0.0001) and higher DCR (p=0.035) were achieved by patients previously treated with paclitaxel-bevacizumab in comparison to those pretreated with other drug combinations or with anthracyclines. Prior treatment with nab-paclitaxel seems to have a detrimental effect on PFS (p=0.0008).

Conclusion

Hormone and HER2 status seems a good predictive and prognostic indicator of response to eribulin. Efficacy seems independent from the number of prior therapies, and it is not influenced by prior endocrine treatments and anthracyclines-containing regimens. On the other hand, sensitivity to a prior treatment with paclitaxel-bevacizumab might be predictive of response to eribulin.

Tumor-Associated Neutrophils in Breast Cancer Subtypes

Background: Tumor associated neutrophils (TAN) are related to aggressiveness and a poor prognosis with human cancers. However, the relevance of TAN in breast cancer has not been previously investigated and here we sought to determine their presence among different subtypes. Methods: We analyzed patients with stage I-III breast cancers between 2006 and 2012. Tumors were divided into three subtypes: hormone-receptor [ HR]-positive, HER2-negative (HR+,HER2-ve); HER2-positive and triple negative (TN). Hematoxylin and eosin stained sections were examined and the number of TAN per 10 high power fields (HPF, 40x) was recorded. Tumors with >1 TAN per 10 HPF were considered TAN-positive. Fisher’s exact test was used to test for independence between qualitative variables, and logistic regression models were applied for multivariate analysis. Results: A total of 133 patients were assessed for inclusion and 105 were analyzed (28 excluded on various criteria). Some 72 tumors (69%) were classified as HR+, HER2-ve, 15 (14%) as HER2+ and 18 (17%) as TN. Totals of 16 TN (88%), 8 HER2+ (53%) and 4 HR+, HER2-ve tumors (5%) were TAN+ (p<0.001), including 79% of HR-ve tumors (19 of 24), in contrast to 11% of their HR+ve counterparts (9 of 81) (p<0.001). HER2 expression (p=0.023) and tumor grade (p<0.001) were also associated with TAN positivity. On multivariate analysis, only HR negativity (OR 16.85; 95% CI 4.4-64.6, p=<0.0001) was associated with a higher likelihood of TAN positivity. Conclusions: TAN are present in most TN tumors. We found an absence of HR expression to be the only predictor of TAN positivity. These results raise the question as to whether TAN, as part of the tumor microenvironment, have a role in the aggressiveness and progression of TN tumors and thus warrant further investigation in this breast cancer subtype, particularly in relation to response to treatment and prognosis.

Comparisons of Oncologic Outcomes between Triple-Negative Breast Cancer (TNBC) and Non-TNBC among Patients Treated with Breast-Conserving Therapy

PURPOSE

The optimum local surgical strategy regarding breast-conserving therapy (BCT) for triple-negative breast cancer (TNBC) is controversial. To investigate whether BCT is appropriate for patients with TNBC, we evaluated the clinical outcomes of BCT in women with TNBC compared to those of women without TNBC, using a large, single-center cohort.

MATERIALS AND METHODS

We performed a retrospective analysis of 1533 women (TNBC n=321; non-TNBC n=1212) who underwent BCT for primary breast cancer between 2000 and 2010. Clinicopathological characteristics, locoregional recurrence-free survival (LRFS), and overall survival (OS) were analyzed.

RESULTS

Tumors from the TNBC group had a higher T stage (T2 37.4% vs. 21.0%, p<0.001), a lower N stage (N0 86.9% vs. 75.5%, p<0.001), and a higher histologic grade (Grade III 66.8% vs. 15.4%, p<0.001) than the non-TNBC group. There were no differences in 5-year LRFS rates between the TNBC and non-TNBC groups (98.7% vs. 97.8%, p=0.63). The non-TNBC group showed a slightly better 5-year OS than the TNBC group; however, the difference was not significant (96.2% vs. 97.3%, p=0.72). In multivariate analyses, TNBC was not associated with poor clinical outcomes in terms of LRFS and OS [hazard ratio (HR) for LRFS=0.37, 95% confidence interval (CI): 0.10-1.31; HR for OS=1.03, 95% CI: 0.31-3.39].

CONCLUSION

TNBC patients who underwent BCT showed non-inferior locoregional recurrence compared to non-TNBC patients with BCT. Thus, BCT is an acceptable surgical approach in patients with TNBC.