Overall Survival In Triple-negative Breast Cancer Patients Research Articles

Exploring the prognostic significance of arm-level copy number alterations in triple-negative breast cancer.

Somatic copy number alterations (SCNAs) are prevalent in cancer and play a significant role in both tumorigenesis and therapeutic resistance. While focal SCNAs have been extensively studied, the impact of larger arm-level SCNAs remains poorly understood. Here, we investigated the association between arm-level SCNAs and overall survival in triple-negative breast cancer (TNBC), an aggressive subtype of breast cancer lacking targeted therapies. We identified frequent arm-level SCNAs, including 21q gain and 7p gain, which correlated with poor overall survival in TNBC patients. Further, we identified the expression of specific genes within these SCNAs associated with survival. Notably, we found that the expression of RIPK4, a gene located on 21q, exhibited a strong correlation with poor overall survival. In functional assays, we demonstrated that targeting Ripk4 in a murine lung metastatic TNBC model significantly reduced tumor burden, improved survival, and increased CD4+ and CD8+ T cell infiltration. RIPK4 enhanced the survival of triple-negative breast cancer cells at secondary sites, thereby facilitating the formation of metastatic lesions. Our findings highlight the significance of arm-level SCNAs in breast cancer progression and identify RIPK4 as a putative driver of TNBC metastasis and immunosuppression.

HISTOPATHOLOGICAL PARAMETERS AND INTRATUMORAL LYMPHOCYTES: CORRELATION WITH SURVIVAL OUTCOMES IN TRIPLE-NEGATIVE BREAST CANCER - A COMPREHENSIVE RETROSPECTIVE ANALYSIS

OBJECTIVE: Triple-negative breast cancer (TNBC) is a subtype characterized by aggressive tumor behavior and limited treatment options. This study aimed to investigate the relationship among age, pathological stage, proliferative index, presence of tumor infiltrating lymphocytes (TILs), and survival outcomes in TNBC. MATERIAL AND METHODS: Tumoral slides and blocks of 31 patients with triple negative breast cancer were retrieved from the pathology archive and retrospectively re-evaluated. The relationship among patient age, histopathological subtype of the tumor, tumor grade, lymph node grade, Ki-67 proliferation index and survival was evaluated. TILs were scored as mild, moderate and severe and the relationship with survival was evaluated. RESULTS: Regarding age and tumor stage, there was no significant correlation found (p=0,81 and p=0,89 respectively). However, when analyzing the N stage, a clear association was observed, with a higher proportion of patients aged 65 years or older displaying advanced N3 stage breast cancer (p=0.000013). A significant relationship was found between TILs and the Ki-67 proliferative index, with cases exhibiting high TILs also demonstrating a high proliferative index (p=0.003). Furthermore, increased TIL concentration was associated with a positive response to therapy and improved overall survival in TNBC patients (p=0.001). CONCLUSIONS: These findings emphasize the importance of considering age, pathological stage, proliferative index, and the presence of TILs in TNBC prognosis. Evaluation of TILs in routine histopathologic examination and inclusion in pathology reports, particularly in postmenopausal patients, could provide valuable information for future studies and guide treatment decisions. Additional research on immune-modulating therapies targeting TILs may hold promise for improving outcomes in TNBC patients.

Abstract 5978: Therapeutic targeting of MELK using a drug repurposing approach to combat TNBC cells

Abstract Background: Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer linked to high chemo-resistant metastatic cases and limited therapeutic options due to the absence of conventional bioreceptors. Therefore, to treat TNBC, it is imperative to identify promising druggable biological targets. Experimental Procedures: An integrated bioinformatic analysis of microarray datasets was performed to identify significantly differentially expressed genes (DEGs) in TNBC. For selecting a potent therapeutic target, the function and significance of the upregulated DEGs in TNBC was investigated by an in silico study employing the UALCAN portal, String database, KM plotter, and Enrichr tools. This analysis included gene expression validation, insights into protein-protein interactions, survival analysis, and pathway mapping of the genes. To obtain potent drugs binding to the selected target MELK (maternal embryonic leucine zipper kinase), a drug repurposing approach was employed starting with virtual screening followed by molecular dynamic simulation (MDS) using GROMACS. Further, the anti-cancer activity of the top two drugs was validated by live-dead imaging, gene expression analyses, MTT-based cell viability and ROS detection assays. Results: Based on a stringent criterion for significant DEG identification (log2|FC|>1 & adjust P-value < 0.05), 25 overlapping upregulated genes were obtained from three selected datasets. Further, in silico analysis revealed that MELK is significantly upregulated across the four stages and subtypes of breast cancer, including TNBC. Higher MELK expression and its oncogenic interactions correlated with poor overall survival of TNBC patients. Evidence suggests that the existing inhibitor for MELK (OTSSP167) has shown poor specificity. Therefore, to block its activity, a library of 1293 FDA-approved drugs was screened against the kinase domain of MELK. MDS study and analysis using parameters like RMSD, RMSF and pair distance revealed that the top 10 drugs were strongly stabilized by H-bonds in the binding pocket of MELK, with minimal deviation and reduced fluctuations of MELK upon drug binding. Binding free energy calculation of drug-MELK interaction using the MM-PBSA method revealed that nine drugs possessed higher binding energy than the inhibitor. The top two drugs obtained from the study (originally kinase and reductase inhibitors respectively) were further validated for their in vitro anti-cancer efficacy in MDA-MB-231 and MDA-MB-468 cells. Treatment with these drugs exhibited (a) a dose-dependent decrease in proliferation, (b) significant cell death, (c) a marked increase in the cellular ROS levels, and (d) a decrease in the expression of MELK and its downstream targets in TNBC cell lines. Conclusion: The present study opens the avenue for using repurposed drugs as potential therapeutic molecules against MELK activity to combat TNBC progression. Citation Format: Arisha Arora, Shilpi Sarkar, Siddhartha S. Ghosh. Therapeutic targeting of MELK using a drug repurposing approach to combat TNBC cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5978.

Abstract 6990: RHBDF1 is a potential modulator of EGFR activation and oncogenic biomarker in triple-negative breast cancer

Abstract Recently, our proteomics study on breast cancer (BC) reported a possible association of RHBDF1 with triple-negative breast cancer (TNBC). The overall survival of TNBC patients on METABRIC data set implicated that the RHBDF1 high-expression group has a shorter life expectancy than the RHBDF1 low-expression group. Although many TNBC patients have high expression levels of RHBDF1 and poor prognosis, the mechanism of RHBDF1 in the pathogenesis of TNBC remained unclear. Rhomboid 5 homolog 1 (RHBDF1) is a catalytically inactive pseudoprotease on the Golgi and endoplasmic reticulum membrane. Despite its inactive status of peptidase, it regulates the activity of ADAM17 protease that cleaves the extracellular portion of EGFR ligands such as TGF alpha and EGF. Eventually, RHBDF1 and ADAM17 complex activate the EGFR signaling pathway, thereby increasing cell proliferation, migration, and tumorigenesis. First of all, we recruited the clinical data of the overall survival (OS) and disease-free survival (DFS) in the hospital of Seoul National University (SNUH cohort, n= 203) and compared IHC score 0 or 1 with survival rate. To investigate the underlying biological mechanism of RHBDF1 in TNBC, the effect of knockdown or overexpression of RHBDF1 was observed in TNBC cell lines (MDA-MB-468, HCC1143 and BT20) using siRNA (small interfering RNA) and lentiviral systems. Cell proliferation assay was performed to clarify whether RHBDF1 affects cell growth. Then, we estimated the ability of migration, invasion, and sphere formation to confirm the characteristics of cancer cells including cancer stemness and metastasis. SNUH cohort with TNBC patients showed that the RHBDF1 high-expression group has a poorer disease-free survival (DFS) than the low-expression group (p<0.05). In vitro assay, RHBDF1 knockdown inhibited proliferation in MDA-MB-468 and HCC1143. RHBDF1 downregulation also decreased the ability of migration and invasion. We found that RHBDF1 activates specific cell growth signaling pathways and increases cell mobility in TNBC. The sphere formation assay was performed to measure cancer stemness characteristics. As a result, RHBDF1 knockdown TNBC cell lines couldn’t form spheres relative to RHBDF1 overexpressed TNBC cell lines. In conclusion, we demonstrated that RHBDF1, a potential triple-negative breast cancer biomarker, is highly amplified in TNBC patients and TNBC cell lines. Its functions of accelerating cell proliferation, metastasis and cancer stemness were unveiled. But we need to study ultimately how RHBDF1 regulates ADAM17 activity at Golgi and endoplasmic reticulum membrane and which transcription factor activates RHBDF1 expression. Citation Format: Hayeon Kim, Soo Young Park, Da Sol Kim, Cheng Hyun Lee, Min Ji Song, Han Suk Ryu. RHBDF1 is a potential modulator of EGFR activation and oncogenic biomarker in triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6990.

Tumor infiltrating lymphocytes (TILs) are a prognosis biomarker in Colombian patients with triple negative breast cancer

Triple negative breast cancer (TNBC) is highly immunogenic and high levels of tumor infiltrating lymphocytes (TILs) have been associated with a better prognosis and higher probability to achieve pathological complete response. Here, we explore the potential role of stromal TILs level and composition as a prognostic and predictive biomarker in TNBC. 195 Tumor biospecimens from patients diagnosed with TNBC were included. Stromal TILs (sTILs), positive CD4/CD8 cells were evaluated. Differences in clinic-pathological characteristics according to immune infiltration were assessed. The predictive and prognostic value of immune infiltration was analyzed by multivariate models. Higher immune infiltration was observed in patients with favorable clinical–pathological features. Survival analysis showed that longer overall survival times were observed in patients with a higher infiltration of sTILs (p = 0.00043), CD4 + (p = 0.0074) and CD8 + (p = 0.008). In the multivariate analysis, low levels of sTILs were found to be associated with a higher mortality hazard (HR: 1.59, 95% CI 1.01–2.48). CD4 and CD8 immune infiltration were associated with higher odds for pathological complete response (OR: 1.20, 95% CI 1.00–1.46, OR: 1.28, 1.02–1.65, respectively). Our results suggest that immune infiltration could be used as a prognostic marker for overall survival in TNBC patients.

Screening protective miRNAs and constructing novel lncRNAs/miRNAs/mRNAs networks and prognostic models for triple-negative breast cancer

Triple-negative breast cancer (TNBC) represents 10–20 % of all breast cancer (BC) cases and is characterized by poor prognosis. Given the urgent need to improve prognostication and develop specific therapies for TNBC, the identification of new molecular targets is of great importance. MicroRNA (miRNA) has been reported as a valuable and novel molecular target in the progression of TNBC. However, the expression and function of miRNAs in different tumors are heterogeneous. Herein, we first analyzed miRNA data from The Cancer Genome Atlas (TCGA) and surprisedly found that overexpressed miRNAs were associated with poor survival in all breast cancer patients, but the overexpressed miRNAs were associated with better survival in TNBC patients. Based on the heterogeneity of miRNA expression in TNBC, we conducted further analysis using univariate Cox proportional hazard regression models and identified 17 miRNAs with prognostic potential. Subsequently, a multivariate Cox model was employed to create a 3-miRNA prognostic model for predicting overall survival in TNBC patients. The diagnostic model exhibited an area under the curve (AUC) of 0.727, and multivariable Cox regression indicated that each covariate was associated with survival. These data indicate that this model is relatively accurate and robust for risk assessment, which have a certain value for clinical application. In order to explore the network behind the overexpressed miRNAs in TNBC, we established a novel network consisting of lncRNAs, miRNAs, and mRNAs through complete transcriptome data from matched samples in the TCGA database. In this network, IRS-1 appeared to be the top hub gene. Experimental results demonstrated that miR-15b-5p and miR-148a-3p effectively target IRS-1 in vitro, shedding light on the intricate regulatory mechanisms in TNBC mediated by the heterogeneous miRNAs. Besides, miR-148a-3p significantly inhibited cell migration and viability. Overall, this study may add valuable insights into the molecular landscape of TNBC based on miRNAs and have the potential to contribute to the development of targeted therapies and improved prognostic strategies of TNBC.

TRIM21 mediates the synergistic effect of Olaparib and Sorafenib by degrading BRCA1 through ubiquitination in TNBC

Triple-negative breast cancer (TNBC) is a heterogeneous and aggressive type of breast cancer with a poor prognosis and a high recurrence rate. Chemotherapy is still the mainstay of treatment for cancer patients without a genetic BRCA mutation, despite the approval of Olaparib, an inhibitor of the poly (ADP-ribose) polymerase (PARP) enzyme. Tripartite motif containing-21 (TRIM21) is one of the TRIM family members that has been investigated in various types of cancer. Here, we found that a low TRIM21 expression level was correlated with poor overall survival of TNBC patients. Knockout of TRIM21 promoted the proliferation of TNBC cells in vivo and in vitro, as well as migratory and invasive capabilities in vitro. Importantly, breast cancer susceptibility gene 1 (BRCA1) was identified as a ubiquitination substrate of TRIM21. It was confirmed that BRCA1 was upregulated after Olaparib treatment, which may explain the relative resistance of BRCA1-proficient TNBC cells to Olaparib. Moreover, Sorafenib, a standard treatment for hepatocellular carcinoma, increased the sensitivity of TNBC cells to Olaparib by promoting TRIM21-mediated ubiquitination degradation of BRCA1. Thus, a synergic effect of Olaparib and Sorafenib was found in vitro and in vivo. This combined treatment also aggravated DNA damage, cell cycle arrest, and apoptosis of TNBC cells. In summary, the findings verified the synergistic effect of Olaparib and Sorafenib and revealed TRIM21 as a potential target for TNBC therapy.

Effect of Lipid Levels on Tumor-Infiltrating Lymphocytes and Prognosis in Patients with Triple-Negative Breast Cancer

Objective: Dyslipidemia can promote cell proliferation, malignant transformation, metastasis, and cancer recurrence. Moreover, it could also affect immune infiltration in the tumor microenvironment. Therefore, we aimed to explore the effects of lipid levels on tumor-infiltrating lymphocytes (TILs) and prognosis in patients with triple-negative breast cancer (TNBC). Methods: Samples from 222 patients with TNBC from July 2007 to December 2019 were obtained from the tissue specimen banks in 3 hospitals. The blood samples were used to detect the levels of lipid levels such as apolipoprotein B (Apo B), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C). The TILs in the 222 TNBC tissues were detected using hematoxylin and eosin (H&E) staining, and the relationship between the lipid levels, clinical characteristics, and prognosis was analyzed. Results: Among TNBC patients, the overall survival (OS) time and disease-free survival (DFS) time were lower in patients with high LDL-C levels than those with low LDL-C levels (p < 0.01, respectively). The DFS was shorter in patients with low stromal TIL (STIL) levels than those with moderate or high STIL levels (p = 0.023). Multifactor Cox regression analysis showed that LDL-C level, Apo B level, and lymphocyte-predominant breast cancer were independent risk factors for OS in TNBC patients. The number of positive lymph nodes, postoperative staging, and total amount of TILs were independent risk factors for DFS in TNBC patients. Conclusion: The LDL-C and STIL levels were correlated with survival and prognosis in patients with TNBC.

A Review on Biomarkers for Predicting Radioresistance and Role of Natural Radiosensitizers in Triple-Negative Breast Cancer

Breast cancer mortality rate is fifth among all cancer and increasing day by day due to modern lifestyles. Its molecular subtype is classified as per their significant receptor expression, such as estrogen receptor (ER), progesterone receptor (PR) &amp; human epidermal growth receptor 2 (Her2). Triple-negative breast cancer (TNBC) is an aggressive subgroup among breast cancer subtypes and clinically challenging to treat due to loss of all three receptor (ER/PR/Her2) expression. Treatment modalities of TNBC include surgery, chemotherapy, radiotherapy and immunotherapy. Postoperative radiation therapy (RT) improves locoregional control and overall survival in TNBC patients. The powerful ionizing radiation (IR) response to RT is contributed by the inherent radiosensitivity of the tumor, which is influenced by genes associated with the cell cycle, DNA damage repair, apoptosis, etc. This review article narrates the role of biomarkers obtained through data mining and manual curation of published literature to predict radioresistance in patients receiving radiotherapy. Further, the role of natural radiosensitizers in overcoming radioresistance for effectively managing TNBC is also discussed.

Prognostic Value of Vimentin in Triple Negative Breast Cancer Patients Depends on Chemotherapy Regimen and p53 Mutant Expression.

To determine the prognostic value of vimentin in triple negative breast cancer (TNBC) patients, specifically in relation to chemotherapy regimen and p53 mutant expression. We retrospectively analyzed the association of pre-treatment tumor expression of vimentin with 48-month overall survival (OS) of 72 all stages TNBC patients diagnosed between 2014 and 2018 in relation to chemotherapy regimen and expression of p53 mutant. Vimentin and p53 mutant expressions were examined using immunohistochemistry. Analysis was conducted on all patients collectively, then repeated on two cohorts divided according to the chemotherapy regimen. Sub-analysis was performed to determine the effect of p53 mutant expression on the prognostic value of vimentin. Vimentin was expressed in 43.1% of patients and was not associated with clinicopathologic characteristics. Vimentin was associated with improved 48-month OS in all patients in univariate analysis but not significant in multivariate analysis. When analyzed according to chemotherapy regimen, vimentin was independently associated with improved 48-month OS in patients receiving non-platinum-based chemotherapy (80% vs 15.8%; HR: 0.17, 95% CI: 0.05-0.58, p: 0.005). Other independent prognostic factors include T (HR: 6.18, 95% CI: 1.38-27.7, p: 0.017) and M (HR: 5.64, 95% CI: 1.2-26.33, p: 0.028). On subanalysis, vimentin was significantly associated with improved 48-month OS in patients expressing p53 mutant (69.2% vs 22.2%, p: 0.006) but was not significant in patients not expressing p53 mutant. Vimentin expression was independently associated with improved 48-month OS in TNBC patients treated with non-platinum-based chemotherapy. Expression of p53 mutant significantly affected the prognostic value of vimentin.

Unveiling the vulnerabilities of synthetic lethality in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is the most invasive molecular subtype of breast cancer (BC), accounting for about nearly 15% of all BC cases reported annually. The absence of the three major BC hormone receptors, Estrogen (ER), Progesterone (PR), and Human Epidermal Growth Factor 2 (HER2) receptor, accounts for the characteristic "Triple negative" phraseology. The absence of these marked receptors makes this cancer insensitive to classical endocrine therapeutic approaches. Hence, the available treatment options remain solemnly limited to only conventional realms of chemotherapy and radiation therapy. Moreover, these therapeutic regimes are often accompanied by numerous treatment side-effects that account for early distant metastasis, relapse, and shorter overall survival in TNBC patients. The rigorous ongoing research in the field of clinical oncology has identified certain gene-based selective tumor-targeting susceptibilities, which are known to account for the molecular fallacies and mutation-based genetic alterations that develop the progression of TNBC. One such promising approach is synthetic lethality, which identifies novel drug targets of cancer, from undruggable oncogenes or tumor-suppressor genes, which cannot be otherwise clasped by the conventional approaches of mutational analysis. Herein, a holistic scientific review is presented, to undermine the mechanisms of synthetic lethal (SL) interactions in TNBC, the epigenetic crosstalks encountered, the role of Poly (ADP-ribose) polymerase inhibitors (PARPi) in inducing SL interactions, and the limitations faced by the lethal interactors. Thus,the future predicament of synthetic lethal interactions in the advancement of modern translational TNBC research is assessed with specific emphasis on patient-specific personalized medicine.

Copy number alteration is an independent prognostic biomarker in triple-negative breast cancer patients.

Next-generation sequencing (NGS) has enabled comprehensive genomic profiling to identify gene alterations that play important roles in cancer biology. However, the clinical significance of these genomic alterations in triple-negative breast cancer (TNBC) patients has not yet been fully elucidated. The aim of this study was to clarify the clinical significance of genomic profiling data, including copy number alterations (CNA) and tumor mutation burden (TMB), in TNBC patients. A total of 47 patients with Stage I-III TNBC with genomic profiling of 435 known cancer genes by NGS were enrolled in this study. Disease-free survival (DFS) and overall survival (OS) were evaluated for their association to gene profiling data. CNA-high patients showed significantly worse DFS and OS than CNA-low patients (p = 0.0009, p = 0.0041, respectively). TMB was not associated with DFS or OS in TNBC patients. Patients with TP53 alterations showed a tendency of worse DFS (p = 0.0953) and significantly worse OS (p = 0.0338) compared with patients without TP53 alterations. Multivariable analysis including CNA and other clinicopathological parameters revealed that CNA was an independent prognostic factor for DFS (p = 0.0104) and OS (p = 0.0306). Finally, multivariable analysis also revealed the combination of CNA-high and TP53 alterations is an independent prognostic factor for DFS (p = 0.0005) and OS (p = 0.0023). We revealed that CNA, but not TMB, is significantly associated with DFS and OS in TNBC patients. The combination of CNA-high and TP53 alterations may be a promising biomarker that can inform beyond standard clinicopathologic factors to identify a subgroup of TNBC patients with significantly worse prognosis.

Abstract P2-11-28: Copy number alteration is an independent prognostic biomarker in triple-negative breast cancer patients

Abstract Background: Triple-negative breast cancer (TNBC) is the most fatal breast cancer subtype, which often shows aggressive progression, a high potential to metastasize, and resistance to chemotherapy. Comprehensive genomic profiling using next-generation sequencing (NGS) has been expected to identify gene alterations that are targetable by drugs. However, the significance of these genomic alterations in the cancer biology of TNBC patients has not yet been fully understood due to the lack of accurate clinical outcome data to compare with the genomic data. The aim of this study was to clarify the clinical impact of genomic profiling data, including copy number alterations (CNAs), in TNBC by comparing comprehensive genomic data with clinical outcomes. Methods: A total of 47 patients diagnosed with stage I-III TNBC (from the cohort reported in JCO Precis Oncol. 2018;2:PO.17.00211) were enrolled in this study. The genomic profiling of 435 known cancer genes by NGS with clinical outcomes were analyzed. Overall survival (OS) was evaluated for its association to gene alterations and distinctively CNAs. The cut-off values of CNA for OS were determined from the receiver operating characteristic curve using the Youden index for area under the curve (AUC). Kaplan-Meier plots and log-rank tests of OS were applied for each group. Univariate and multivariate analyses for OS were performed using a Cox proportional-hazards model to obtain the hazard ratio (HR) and 95% confidence intervals. Results: Utilizing NGS-based genomic profiling, at least one alteration was found in 82 of the 435 cancer-associated genes, and a total of 162 alterations were found in the 47 patients. Among the 82 genes with alterations, the presence or absence of TP53 and PTEN alterations was significantly associated with OS of TNBC patients; patients with TP53 alterations (n = 31) showed significantly shorter OS than those without TP53 alterations (n = 16, p = 0.023), and patients with PTEN alterations (n = 9) showed significantly shorter OS than those without PTEN alterations (n = 38, p = 0.023). The cut-off value of CNA for OS was set at 25 (AUC, 0.788; sensitivity, 0.727; specificity, 0.900). Interestingly, CNA-high patients (n = 20) showed significantly shorter OS than CNA-low patients (n = 27, p = 0.014). Univariate analysis revealed that TP53 alterations and CNAs were significant prognostic factors for OS (HR, 8.81; p = 0.008; and HR, 8.00; p = 0.014, respectively). Finally, multivariate analysis using background clinical data revealed that CNA was an independent prognostic factor for OS in TNBC patients (HR, 7.15; p = 0.044). Conclusion: Our data suggest that CNA is an independent prognostic marker in TNBC, and that can be estimated from comprehensive genomic profiling data by NGS. Further investigation is needed to clarify the mechanisms of how CNAs are associated with this lethal disease. Citation Format: Masayuki Nagahashi, Chie Toshikawa, YiWei Ling, Tetsu Hayashida, Yuko Kitagawa, Manabu Futamura, Takashi Kuwayama, Seigo Nakamura, Hideko Yamauchi, Teruo Yamauchi, Koji Kaneko, Chizuko Kanbayashi, Nobuaki Sato, Junko Tsuchida, Kazuki Moro, Masato Nakajima, Yoshifumi Shimada, Hiroshi Ichikawa, Stephen Lyle, Yasuo Miyoshi, Kazuaki Takabe, Shujiro Okuda, Toshifumi Wakai. Copy number alteration is an independent prognostic biomarker in triple-negative breast cancer patients [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-11-28.

Transcriptomic profiles-based approach to decode the role of miR-122 in triple negative breast cancer.

miR-122 has been considered both as tumor suppressor miRNA and oncomiR in breast tumor phenotypes. However, the role of miR-122 in triple-negative breast cancer (TNBC) is still unknown. In this study, the clinical value of miR-122 was used to describe the transcriptomic landscape of TNBC tumors obtained from The Cancer Genome Atlas database. Low expression levels of miR-122 were associated with poor overall survival (OS) of TNBC patients than those with higher expression levels of miR-122. We identified gene expression profiles in TNBC tumors expressed lower or higher miR-122. Gene coexpression networks analysis revealed gene modules and hub genes specific to TNBC tumors with low or high miR-122 levels. Gene ontology and KEGG pathways analysis revealed that gene modules in TNBC with gain of miR-122 were related to cell cycle and DNA repair, while in TNBC with loss of miR-122 were enriched in cell cycle, proliferation, apoptosis and activation of cell migration and invasion. The expression of hub genes distinguished TNBC tumors with gain or loss of miR-122 from normal breast tissues. Furthermore, high levels of hub genes were associated with better OS in TNBC patients. Interestingly, the gene coexpression network related to loss of miR-122 were enriched with target genes of miR-122, but this did not observed in those with gain of miR-122. Target genes of miR-122 are oncogenes mainly associated with cell differentiation-related processes. Finally, 75 genes were identified exclusively associated to loss of miR-122, which are also implicated in cell differentiation. In conclusion, miR-122 could act as tumor suppressor by controlling oncogenes in TNBC.

Expression of CD22 in Triple-Negative Breast Cancer: A Novel Prognostic Biomarker and Potential Target for CAR Therapy.

Triple-negative breast cancer (TNBC) accounts for 15-20% of all breast cancer cases. Due to the lack of expression of well-known molecular targets [estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2)], there is a need for more alternative treatment approaches in TNBC. Chimeric antigen receptor (CAR)-T cell-based immunotherapy treatment is one of the latest treatment technologies with outstanding therapeutic advances in the past decade, especially in the treatment of hematologic malignancies, but the therapeutic effects of CAR-T cells against solid tumors have not yet shown significant clinical benefits. Identification of highly specific CAR-T targets in solid tumors is also crucial for its successful treatment. CD22 is reported to be a multifunctional receptor that is mainly expressed on the surface of mature B-cells (lymphocytes) and is also highly expressed in most B-cell malignancies. This study aimed to investigate the expression of CD22 in TNBC. Bioinformatic analysis was performed to evaluate the expression of CD22 in breast carcinoma and normal tissues. RNA-seq data of normal and breast carcinoma patients were downloaded from The Cancer Genome Atlas (TCGA), and differential gene expression was performed using R language. Additionally, online bioinformatics web tools (GEPIA and TNM plot) were used to evaluate the expression of CD22 in breast carcinoma and normal tissues. Western blot (WB) analysis and immunofluorescence (IF) were performed to characterize the expression of CD22 in TNBC cell lines. Immunohistochemical (IHC) staining was performed on tumor specimens from 97 TNBC patients for CD22 expression. Moreover, statistical analysis was performed to analyze the association of clinical pathological parameters with CD22 expression. Correlation analysis between overall survival data of TNBC patients and CD22 expression was also performed. Differential gene expression analysis of TCGA data revealed that CD22 is among the upregulated differentially expressed genes (DEGs) with high expression in breast cancer, as compared to normal breast tissues. WB and IF analysis revealed high expression of CD22 in TNBC cell lines. IHC results also showed that approximately 62.89% (61/97) of TNBC specimens were stained positive for CD22. Cell membrane expression of CD22 was evident in 23.71% (23/97) of TNBC specimens, and 39.18% (38/97) of TNBC specimens showed cytoplasmic/membrane expression, while 37.11% (36/97) specimens were negative for CD22. Furthermore, significant associations were found between the size of tumors in TNBC patients and CD22 expression, which unveils its potential as a prognostic biomarker. No significant correlation was found between the overall survival of TNBC patients and CD22 expression. In conclusion, we demonstrated for the first time that CD22 is highly expressed in TNBC. Based on our findings, we anticipated that CD22 could be used as a prognostic biomarker in TNBC, and it might be a potential CAR-T target in TNBC for whom few therapeutic options exist. However, more large-scale studies and clinical trials will ensure its potential usefulness as a CAR-T target in TNBC.

SMAGP regulates doxorubicin sensitivity in triple-negative breast cancer cells via modulating mitochondrial respiration.

Doxorubicin-based chemotherapy remains as a major therapeutic approach for patients with triple-negative breast cancer (TNBC). However, insensitivity or resistance to doxorubicin treatment limits the therapeutic efficacy. Mitochondrial respiration plays a critical role in regulating the sensitivity of cancer cells to chemotherapy drugs. Here, we found that small trans-membrane and glycosylated protein (SMAGP) is upregulated in TNBC cells in comparison to normal breast and other subtypes of breast cancer cells. High SMAGP expression is associated with poorer overall survival of TNBC patients. Importantly, loss of SMAGP enhanced the sensitivity of TNBC cells to doxorubicin treatment. Mechanistically, we detected a functional pool of SMAGP in the mitochondria of TNBC cells controlling doxorubicin sensitivity via regulating mitochondrial respiration. Thus, our data suggest that SMAGP acts as a novel regulator of doxorubicin sensitivity in TNBC, identifying SMAGP as a promising therapeutic target for improving the efficacy of doxorubicin-based chemotherapy in TNBC patients.

Impact of platinum-based chemotherapy on the prognosis of early triple-negative breast cancer: a systematic review and meta-analysis.

Although platinum-based chemotherapy can improve pathologic complete response (pCR) in patients with triple-negative breast cancer (TNBC), the impact on survival of platinum-based neoadjuvant and adjuvant chemotherapy is still controversial. Our meta-analysis aimed at analyzing survival with platinum-based neoadjuvant and adjuvant chemotherapy in patients with TNBC. We searched PubMed, EMBASE, MEDLINE, Cochrane databases, and several major conferences up to January 2021. Fixed and random models were used for our meta-analysis. Disease-free survival (DFS), overall survival (OS), and side effects data were extracted from the included literature in addition to the corresponding pooled hazard ratio (HR) and odds ratio (OR) with 95% confidence intervals (CIs). A total of nine studies involving 3247 patients were included. The pooled analysis suggested that compared with anthracycline- and/or paclitaxel-based chemotherapy, platinum-based chemotherapy could further improve DFS (HR = 0.56, 95% CI 0.45-0.67, p < 0.01) and OS (HR = 0.54, 95% CI 0.38-0.70, p < 0.01) in patients with TNBC. The subgroup analysis showed that platinum-based chemotherapy could further improve DFS (HR = 0.59, 95% CI 0.43-0.74, p < 0.01) and OS (HR = 0.61, 95% CI 0.40-0.83, p < 0.01) in neoadjuvant chemotherapy and DFS (HR = 0.53, 95% CI 0.37-0.69, p < 0.01) and OS (HR = 0.46, 95% CI 0.23-0.69, p < 0.01) in adjuvant chemotherapy compared with anthracycline- and/or paclitaxel-based chemotherapy in patients with TNBC. In addition, compared with anthracycline-based chemotherapy, platinum-based chemotherapy without anthracycline chemotherapy could further improve DFS (HR = 0.53, 95% CI 0.37-0.70, p < 0.01) and OS (HR = 0.46, 95%CI 0.19-0.72, p < 0.01) in patients with TNBC. Compared with anthracycline- and/or paclitaxel-based chemotherapy, all-grade diarrhea, fatigue, and grade ≥ 3 anemia were higher in platinum-based chemotherapy. In contrast, all-grade anemia, leukopenia, neutropenia, peripheral neuropathy, myalgia/arthralgia, cardiac toxicity were lower in platinum-based chemotherapy; grade ≥ 3 leukopenia, neutropenia and myalgia/arthralgia were also lower. Compared with anthracycline- and/or paclitaxel-based chemotherapy, platinum-based chemotherapy was more associated with improved DFS and OS in TNBC patients. The benefit of survival is consistent with platinum-based neoadjuvant and adjuvant chemotherapy. The side effects of platinum-based chemotherapy are tolerable.

Dynamic tumor microenvironment, molecular heterogeneity, and distinct immunologic portrait of triple-negative breast cancer: an impact on classification and treatment approaches.

Heterogeneity of the tumor microenvironment (TME) and the lack of a definite targetable receptor in triple-negative breast cancer (TNBC) has carved a niche for this cancer as a particularly therapeutically challenging form of breast cancer. However, recent advances in high-throughput genomic analysis have provided new insights into the unique microenvironment and defining characteristics of various subsets of TNBC. This improved understanding has contributed to the development of novel therapeutic strategies including targeted therapies such as PARP inhibitors and CDK inhibitors. Moreover, the recent FDA approval of the immune checkpoint inhibitor against programmed cell death protein 1 (PD-1), pembrolizumab and atezolizumab, holds the promise of improving the quality of life and increasing the overall survival of TNBC patients. This recent approval is one of the many therapeutically novel strategies that are currently being exploited in clinical trials toward eventual contribution to the oncologist's toolbox against TNBC. In this review, we comprehensively discuss TNBC's distinct TME and its immunophenotype. Furthermore, we highlight the histological and molecular classification of this cancer. More importantly, we describe how these characteristics and classifications contribute to the current standards of care and how they steer the development of newer and more targeted therapies toward achieving peak therapeutic goals in the treatment of TNBC.

Cancer-associated adipocytes release FUCA2 to promote aggressiveness in TNBC

Cancer-associated adipocytes (CAAs) have been suggested to promote tumor progression. Yet, the role of CAAs in triple-negative breast cancer (TNBC) is poorly investigated. We compared the expression of secretory protein-encoding genes in CAAs and control adipocytes. The effect of key secretory protein(s) on TNBC cell behaviors was explored. CAAs expressed and secreted FUCA2 at greater levels than control adipocytes. When FUCA2 activity was blocked with a neutralizing antibody, TNBC cell proliferation and migration induced by CAA-conditioned medium was impaired. In contrast, supplement of exogenous FUCA2 protein reinforced the proliferation, colony formation, and migration of TNBC cells. In vivo studies confirmed that FUCA2 exposure enhanced tumorigenesis and metastasis of TNBC cells. Mechanistic investigation revealed that FUCA2 induced TNBC aggressiveness through TM9SF3-dependent signaling. Depletion of TM9SF3 blocked CAA- and FUCA2-induced TNBC cell proliferation and migration. Compared to adjacent breast tissues, TNBC tissues had increased expression of TM9SF3. Moreover, high TM9SF3 expression was associated with advanced TNM stage, lymph node metastasis, and shorter overall survival of TNBC patients. Altogether, CAAs secrete FUCA2 to promote TNBC growth and metastasis through interaction with TM9SF3. Inhibition of TM9SF3 may represent a potential therapeutic strategy in the treatment of TNBC.

Abstract P3-20-08: Does contralateral prophylactic mastectomy improve survival in triple negative breast cancer?

Abstract Background: Despite increased incidence of contralateral prophylactic mastectomy (CPM), there is insufficient evidence that it improves survival in women at average risk for breast cancer. In addition to BRCA1/2 mutation carriers, patients with estrogen-receptor negative tumors have been examined as a subgroup that may seek to benefit from CPM. In this study, we sought to investigate whether CPM improves survival in patients with triple negative breast cancer (TNBC).Study Design: Survival outcomes were evaluated for all TNBC patients from a multi-institutional database from 1999-2018 at New York Presbyterian - Weill Cornell Medical Center and Henry Ford Health System. Median follow-up time was 44.4 months.Results: 802 TNBC patients were evaluated. The median age was 57 years. 17% patients underwent CPM. Factors associated with CPM were White American race, younger age, presence of lymphovascular invasion (LVI), lack of mammography screen-detection, mastectomy surgery, postoperative adjuvant radiotherapy, and having had genetic testing. A borderline significant trend was observed in improved overall survival among patients undergoing CPM versus those not having CPM (5-year OS 95.1% vs. 85.0%; p = 0.05). Subset analysis of patients younger than 50 years of age at diagnosis demonstrated no improvement in overall survival for patients undergoing CPM versus those that declined CPM (94.3% v. 88.7%; p = 0.21). Conclusion: Our data demonstrate a trend in improved 5-year overall survival in TNBC patients undergoing CPM. However, in patients younger than 50 years at diagnosis, CPM did not confer a survival advantage. Citation Format: Genevieve A Fasano, Solange Bayard, Yalei Chen, Jennifer Marti, Rache Simmons, Alexander Swistel, Jessica Bensenhaver, S David Nathanson, Lindsay Petersen, Erica Proctor, Melissa Davis, Lisa Newman. Does contralateral prophylactic mastectomy improve survival in triple negative breast cancer? [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-20-08.