Triple-negative Breast Cancer Subtype Research Articles

Density of tertiary lymphoid structures predicts clinical outcome in breast cancer brain metastasis

BackgroundPatients with breast cancer brain metastases (BCBM) experience a rapid decline in their quality of life. Recently, tertiary lymphoid structures (TLSs), analogs of secondary lymphoid organs, have attracted extensive attention....

Upregulated Nuclear Expression of Soluble Epoxide Hydrolase Predicts Poor Outcome in Breast Cancer Patients: Importance of the Digital Pathology Approach.

Breast cancer (BC) is the most common cancer in women, with incidence rates increasing globally in recent years. Therefore, it is important to find new molecules with prognostic and therapeutic value to improve therapeutic response and quality of life. The polyunsaturated fatty acids (PUFAs) metabolic pathway participates in various physiological processes, as well as in the development of malignancies. Although aberrancies in the PUFAs metabolic pathway have been implicated in carcinogenesis, the functional and clinical relevance of this pathway has not been well explored in BC. To evaluate the clinical significance of soluble epoxide hydrolase (EPHX2) expression in Mexican patients with BC using tissue microarrays (TMAs) and digital pathology (DP). Immunohistochemical analyses were performed on 11 TMAs with 267 BC samples to quantify this enzyme. Using DP, EPHX2 protein expression was evaluated solely in tumor areas. The association of EPHX2 with overall survival (OS) was detected through bioinformatic analysis in public databases and confirmed in our cohort via Cox regression analysis. Clear nuclear expression of EPHX2 was identified. Receiver operating characteristics (ROC) curves revealed the optimal cutoff point at 2.847062 × 10-3 pixels, with sensitivity of 69.2% and specificity of 67%. Stratification based on this cutoff value showed elevated EPHX2 expression in multiple clinicopathological features, including older age and nuclear grade, human epidermal growth factor receptor 2 (HER2) and triple negative breast cancer (TNBC) subtypes, and recurrence. Kaplan-Meier curves demonstrated how higher nuclear expression of EPHX2 predicts shorter OS. Consistently, multivariate analysis confirmed EPHX2 as an independent predictor of OS, with a hazard ratio (HR) of 3.483 and a 95% confidence interval of 1.804-6.724 (p < 0.001). Our study demonstrates for the first time that nuclear overexpression of EPHX2 is a predictor of poor prognosis in BC patients. The DP approach was instrumental in identifying this significant association. Our study provides valuable insights into the potential clinical utility of EPHX2 as a prognostic biomarker and therapeutic target in BC.

Long noncoding RNA profiling unveils LINC00960 as unfavorable prognostic biomarker promoting triple negative breast cancer progression

Long noncoding RNAs (lncRNAs) play a critical role in breast cancer pathogenesis, including Triple-Negative Breast Cancer (TNBC) subtype. Identifying the lncRNA expression patterns across different breast cancer subtypes could provide valuable insights into their potential utilization as disease biomarkers and therapeutic targets. In this study, we profiled lncRNA expression in 96 breast cancer cases, revealing significant differences compared to normal breast tissue. Variations across breast cancer subtypes, including Hormone Receptor-positive (HR + ), HER2-positive (HER2 + ), HER2 + HR + , and TNBC, as well as in relation to tumor grade and patients’ age at diagnosis were observed. TNBC and HER2+ subtypes showed distinct clustering, while HER2 + HR+ tumors clustered closer to HR+ tumors based on their lncRNA profiles. Our data identified numerous enriched lncRNAs in TNBC, notably the elevated expression of LINC00960, which was subsequently validated in two additional datasets. Analysis of LINC00960 expression in an independent TNBC cohort (n = 360) revealed elevated expression of LINC00960 to correlate with cell movement, invasion, proliferation, and migration functional categories. Depletion of LINC00960 significantly reduced TNBC cell viability, colony formation, migration, and three-dimensional growth, while increasing cell death. Mechanistically, transcriptomic profiling of LINC00960-depleted cells confirmed its tumor-promoting role, likely through sponging of hsa-miR-34a-5p, hsa-miR-16-5p, and hsa-miR-183-5p, leading to the upregulation of cancer-promoting genes including BMI1, KRAS, and AKT3. Our findings highlight the distinct lncRNA expression patterns in breast cancer subtypes and underscore the crucial role for LINC00960 in promoting TNBC pathogenesis, suggesting its potential utilization as a prognostic marker and therapeutic target.

CCN6 Suppresses Metaplastic Breast Carcinoma by Antagonizing Wnt/β-Catenin Signaling to Inhibit EZH2-Driven EMT.

Metaplastic breast carcinomas (mBrCA) are a highly aggressive subtype of triple-negative breast cancer with histologic evidence of epithelial-to-mesenchymal transition and aberrant differentiation. Inactivation of the tumor suppressor gene cellular communication network factor 6 (CCN6; also known as Wnt1-induced secreted protein 3) is a feature of mBrCAs, and mice with conditional inactivation of Ccn6 in mammary epithelium (Ccn6-KO) develop spindle mBrCAs with epithelial-to-mesenchymal transition. Elucidation of the precise mechanistic details of how CCN6 acts as a tumor suppressor in mBrCA could help identify improved treatment strategies. In this study, we showed that CCN6 interacts with the Wnt receptor FZD8 and coreceptor LRP6 on mBrCA cells to antagonize Wnt-induced activation of β-catenin/TCF-mediated transcription. The histone methyltransferase EZH2 was identified as a β-catenin/TCF transcriptional target in Ccn6-KO mBrCA cells. Inhibiting Wnt/β-catenin/TCF signaling in Ccn6-KO mBrCA cells led to reduced EZH2 expression, decreased histone H3 lysine 27 trimethylation, and deregulation of specific target genes. Pharmacologic inhibition of EZH2 reduced growth and metastasis of Ccn6-KO mBrCA mammary tumors in vivo. Low CCN6 is significantly associated with activated β-catenin and high EZH2 in human spindle mBrCAs compared with other subtypes. Collectively, these findings establish CCN6 as a key negative regulator of a β-catenin/TCF/EZH2 axis and highlight the inhibition of β-catenin or EZH2 as a potential therapeutic approach for patients with spindle mBrCAs. Significance: CCN6 deficiency drives metaplastic breast carcinoma growth and metastasis by increasing Wnt/β-catenin activation to upregulate EZH2, identifying EZH2 inhibition as a mechanistically guided treatment strategy for this deadly form of breast cancer.

MAZ-mediated up-regulation of BCKDK reprograms glucose metabolism and promotes growth by regulating glucose-6-phosphate dehydrogenase stability in triple-negative breast cancer

Tumour metabolic reprogramming is pivotal for tumour survival and proliferation. Investigating potential molecular mechanisms within the heterogeneous and clinically aggressive triple-negative breast cancer (TNBC) subtype is essential to identifying novel therapeutic targets. Accordingly, we investigated the role of branched-chain α-keto acid dehydrogenase kinase (BCKDK) in promoting tumorigenesis in TNBC. We analysed The Cancer Genome Atlas dataset and immunohistochemically stained surgical specimens to investigate BCKDK expression and its prognostic implications in TNBC. The effects of BCKDK on tumorigenesis were assessed using cell viability, colony formation, apoptosis, and cell cycle assays, and subsequently validated in vivo. Metabolomic screening was performed via isotope tracer studies. The downstream target was confirmed using mass spectrometry and a co-immunoprecipitation experiment coupled with immunofluorescence analysis. Upstream transcription factors were also examined using chromatin immunoprecipitation and luciferase assays. BCKDK was upregulated in TNBC tumour tissues and associated with poor prognosis. BCKDK depletion led to reduced cell proliferation both in vitro and vivo. MYC-associated zinc finger protein (MAZ) was confirmed as the major transcription factor directly regulating BCKDK expression in TNBC. Mechanistically, BCKDK interacted with glucose-6-phosphate dehydrogenase (G6PD), leading to increased flux in the pentose phosphate pathway for macromolecule synthesis and detoxification of reactive oxygen species. Forced expression of G6PD rescued the growth defect in BCKDK-deficient cells. Notably, the small-molecule inhibitor of BCKDK, 3,6-dichlorobenzo(b)thiophene-2-carboxylic acid, exhibited anti-tumour effects in a patient-derived tumour xenograft model. Our findings hold significant promise for developing targeted therapies aimed at disrupting the MAZ/BCKDK/G6PD signalling pathway, offering potential advancements in treating TNBC through metabolic reprogramming.

Beyond Triple-Negative: High Prevalence of Quadruple-Negative Breast Cancer in African Americans.

Quadruple-negative breast cancer (QNBC) is a triple-negative breast cancer (TNBC) subtype that lacks expression of the androgen (AR) receptor. Few studies have focused on this highly aggressive breast cancer, portending worse survival rates. We aimed to determine the following: (1) QNBC's molecular and clinical characteristics and compare them with other subtypes and (2) QNBC's association with clinicopathological factors and prognostic markers. We performed immunohistochemical evaluations of ARs on tissue tumor microarrays from FFPE tumor blocks of invasive ductal breast carcinomas in 202 African American women. Univariate analysis was performed using the chi-square test, with survival rates calculated using Kaplan-Meier curves. Overall, 75.8% of TNBCs were AR-negative. Compared to the luminal subtypes, TNBC and QNBC tumors were likely to be a higher grade (p < 0.001); HER2+/AR- and QNBCs were also larger than the other subtypes (p < 0.001). They also expressed increasing mean levels of proteins involved in invasion, such as CD44, fascin, and vimentin, as well as decreasing the expression of proteins involved in mammary differentiation, such as GATA3 and mammaglobin. We found no association between QNBC and stage, recurrence-free survival, or overall survival rates. The high prevalence of TNBC AR-negativity in these women could explain observed worse outcomes, supporting the existence of the unique QNBC subtype.

Neoadjuvant Chemotherapy Response in Triple-Negative Apocrine Carcinoma: Comparing Apocrine Morphology, Androgen Receptor, and Immune Phenotypes.

Apocrine differentiation and androgen receptor (AR) positivity represent a specific subset of triple-negative breast cancer (TNBC) and are often considered potential prognostic or predictive factors. To evaluate the response of TNBC to neoadjuvant chemotherapy (NAC) and to assess the impact of apocrine morphology, AR status, Ki-67 labeling index (Ki-67LI), and tumor-infiltrating lymphocytes (TILs). A total of 232 TNBC patients who underwent NAC followed by surgical resection in a single institute were analyzed. The study evaluated apocrine morphology and AR and Ki-67LI expression via immunohistochemistry from pre-NAC biopsy samples. Additionally, pre-NAC intratumoral TILs and stromal TILs (sTILs) were quantified from biopsies using a deep learning model. The response to NAC after surgery was assessed based on residual cancer burden. Both apocrine morphology and high AR expression correlated with lower Ki-67LI (P < .001 for both). Apocrine morphology was associated with lower postoperative pathologic complete response (pCR) rates after NAC (P = .02), but the difference in TILs between TNBC cases with and without apocrine morphology was not statistically significant (P = .09 for sTILs). In contrast, AR expression did not significantly affect pCR (P = .13). Pre-NAC TILs strongly correlated with postoperative pCR in TNBCs without apocrine morphology (P < .001 for sTILs), whereas TNBC with apocrine morphology demonstrated an indeterminate trend (P = .82 for sTILs). Although TIL counts did not vary significantly based on apocrine morphology, apocrine morphology itself was a more reliable predictor of NAC response than AR expression. Consequently, although apocrine morphology is a rare subtype of TNBC, its identification is clinically important.

Bioinformatic Investigation of Genetic Changes in Paraoxonase Genes in Breast Cancer and Breast Cancer Subtypes.

Among women, breast cancer (BC) is the most prevalent form of cancer. Many molecular targets have been discovered for BC prognosis and treatment. However, new markers still need to be identified, as cancer pathogenesis is triggered by different mechanisms. The aim of this study was to examine the changes in the paraoxonase genes (PON1, PON2, and PON 3) involved in the pathogenesis of BC. The characteristics of the mutations were evaluated with the Cbioportal database. Kaplan-Meier Plot evaluated recurrence-free survival (RFS). The UALCAN database determined the promoter methylation. Gene expression was evaluated by GEPIA2.0 database. PON1 harbored the most mutations. There was a significant decrease in PON3 expression levels in BC samples compared with healthy samples. PON1 and PON2 expression levels did not differ between BC tissue and normal adjacent tissue. Elevated expression levels of PON1 and PON2 genes were correlated with longer RFS, whereas reduced expression of the PON2 gene showed an association with longer RFS. Moreover, the promoter regions of PON1 and PON 3 were found to be hypermethylated, while the promoter region of PON 2 was found to be hypomethylated. The PON3 promoter region was significantly hypermethylated in luminal and human epidermal growth factor receptor 2 (HER2) + BC subtypes. However, the PON3 promoter region was significantly hypomethylated in the triple negative breast cancer (TNBC) subtype. These results suggest that methylation and expression status of PON3 in BC and BC subtypes (TNBC, luminal and HER2) may indicate a poor prognosis. The PON3 gene could be a negative prognostic marker in BC. However, the results should be supported by prospective studies.

Role of AURKB Inhibition in Reducing Proliferation and Enhancing Effects of Radiotherapy in Triple-Negative Breast Cancer.

Breast cancer is a leading cause of cancer-related deaths in females. Triple-negative breast cancer (TNBC) subtype is the most aggressive form of breast cancer that lacks biomarkers and effective targeted therapies. Its high degree of heterogeneity as well as innate and acquired resistance to treatment creates further barriers in achieving positive clinical outcomes in TNBC. Thus, development of novel treatment approaches in TNBC is of high clinical significance. Multimodality approaches with targeted agents and radiotherapy (RT) are promising for increasing efficacy of treatment and circumventing resistance. Here we examined anticancer effects of the Aurora Kinase B (AURKB) inhibitor AZD1152 as a single agent and in combination with RT using various TNBC cell lines, MDA-MB-468, MDA-MB-231 and SUM-159. We observed that AZD1152 alone effectively inhibited colony formation in TNBC cell lines. The combination of AZD1152 at IC50 concentrations together with ionizing radiation further reduced colony formation as compared to the single agent treatment. Our data support the notion that inhibition of the AURKB pathway is a promising strategy for treatment and radiosensitization of TNBC and warrants further translational studies.

Survival analysis for patients with metachronous contralateral breast cancer: Insights from a retrospective study.

Continued advances in the diagnosis and treatment of breast cancer (BC) have led to an increase in the number of long-term BC survivors and an increase in the incidence of metachronous BC in the contralateral breast. Therefore, it is important to understand the factors that influence the development of metachronous BC; however, the impact of the laterality of the initial ipsilateral (I)BC as a risk factor for the development of metachronous contralateral (MC)BC has not been extensively investigated. The present study included 17,082 female patients with stage 0-3 IBC from the prospectively maintained Korean Breast Cancer Registry from 1989-2013 and divided them into two groups: Patients with MCBC (n=88) and those without MCBC (n=16,994). Risk factors that present at the initial BC diagnosis that could significantly influence the development of MCBC were screened for and risks were evaluated using the Fine-Gray subdistribution hazard model. Significant differences in baseline characteristics between MCBC and non-MCBC groups were demonstrated. Patients aged <40 years, those with histological and nuclear grade 3 tumors, and those with the triple-negative BC subtype were significantly more prevalent in the MCBC group than in the non-MCBC group. Additionally, the cumulative incidence of MCBC increased over time, with a notable increase from 0.1% in year 1 to 1.6% in year 10. Survival analysis revealed no significant differences in overall or BC-specific survival between the two groups. Key predictive factors identified for MCBC included an age of <40 years at initial diagnosis, a negative progesterone receptor status, and a Ki-67 score of >14%. Overall, the present study revealed several factors associated with MCBC and emphasized the need for long-term monitoring of BC survivors, considering these newly identified risk factors.

Integrated Transcriptome Analysis of Radioresistant Cells Revealed Genes and Pathways Predictive Of Tumor Response to Radiotherapy and Chemotherapy in Breast Cancer

AbstractBreast cancer cells exposed to radiotherapy frequently develop radiation resistance through molecular and phenotypic changes. While there is evidences of pathways controlling radioresistance, the evolution of diverse cell phenotypes and transcriptional changes as mediators of radioresistance in breast cancer are restricted. Moreover, the effectiveness of the chemotherapy on radioresistant cells remains uncertain. In this work, an isogenic model of radioresistant breast cancer cells (RR cells) is used to study this phenotype. RR cells show high survival rates after radiation, moreover, RR cells of the triple negative breast cancer (TNBC) subtype show a significantly advanced invasiveness phenotype. Notably, RR cells are significantly sensitive to chemotherapy by inhibit cell survival and promote apoptosis. Transcriptomics and gene co‐expression network analysis identify differentially expressed genes (DEGs) and hub genes related to survival and apoptosis pathways in the RR cells of luminal subtype, while in TNBC subtype, cell migration, cell differentiation, and immune pathways are enriched. Hub genes predict the failure of radiotherapy in breast cancer patients, but they are also related to pathological complete response after chemotherapy. Transcriptome changes during acquired radioresistance uncover genes and pathways associated to radio and chemotherapy response. These results demonstrate that radioresistant pathways may converge to develop collateral chemo‐sensitivity.

Small Molecule Therapeutics in the Pipeline Targeting for Triple-Negative Breast Cancer: Origin, Challenges, Opportunities, and Mechanisms of Action.

Triple-negative breast cancer (TNBC) cells are devoid of estrogen receptors (ERs), progesterone receptor (PRs), and human epidermal growth factor receptor 2 (HER2), and it (TNBC) counts for about 10-15% of all breast cancers. TNBC is highly invasive, having a faster growth rate and a higher risk of metastasis and recurrence. Still, chemotherapy is one of the widely used options for treating TNBC. This study reviewed the histological and molecular characterization of TNBC subtypes, signaling pathways that are aberrantly expressed, and small molecules targeting these pathways, as either single agents or in combination with other therapeutic agents like chemotherapeutics, immunotherapeutics, and antibody-drug conjugates; their mechanisms of action, challenges, and future perspectives were also reviewed. A detailed analytical review was carried out using the literature collected from the SciFinder, PubMed, ScienceDirect, Google Scholar, ACS, Springer, and Wiley databases. Several small molecule inhibitors were found to be therapeutics for treating TNBC. The mechanism of action and the different signaling pathways through which the small molecules exert their effects were studied, including clinical trials, if reported. These small molecule inhibitors include buparlisib, everolimus, vandetanib, apatinib, olaparib, salidroside, etc. Some of the signaling pathways involved in TNBC, including the VEGF, PARP, STAT3, MAPK, EGFR, P13K, and SRC pathways, were discussed. Due to the absence of these biomarkers, drug development for treating TNBC is challenging, with chemotherapy being the main therapeutic agent. However, chemotherapy is associated with chemoresistance and a high toxicity to healthy cells as side effects. Hence, there is a continuous demand for small-molecule inhibitors that specifically target several signaling pathways that are abnormally expressed in TNBC. We attempted to include all the recent developments in this field. Any omission is truly unintentional.

Predicting locoregional recurrence in triple-negative breast cancer using novel molecular subtyping.

e12549 Background: Triple-negative breast cancer (TNBC) presents a poorer prognosis compared to other breast cancer subtypes, characterized by a higher likelihood of early recurrence and increased incidence of visceral metastases. Evidence from numerous randomized clinical trials indicates that postmastectomy radiotherapy (PMRT) reduces locoregional recurrence (LRR) and improves breast cancer survival in TNBC. Previous reports creatively divided TNBC into four molecular subtypes for personalized treatment. The present study aims to elucidate patterns of LRR in different subtypes of TNBC after PMRT. Methods: From 2019 to 2022, data from 349 AJCC 7th edition stage II-III breast cancer patients treated with mastectomy and PMRT were retrospectively analyzed. These patients were classified into the basal-like immune-suppressed (BLIS) and non-BLIS groups based on the immunohistochemistry biomarkers. The cumulative incidence function was applied to estimated LRR rates, with death as a competing risk, using Gray's test for comparisons. Results: According to the IHC results, a total of 255 patients belonged to the non-BLIS group and 94 to the BLIS group. The 3-year LRR for the entire cohort was 5.16%. There were 9 cases each in the non-BLIS subtype (3.5%) and BLIS subtype (9.6%). The cumulative incidence of LRR between the two groups was significantly different, with a rate of 4.0% in the non-BLIS group and 9.0% in the BLIS group ( P = 0.02). Among the 18 patients with LRR in the whole population, 11 had isolated LRR and 7 were diagnosed with LRR with concurrent distant metastases. The most common area of recurrence in both subtypes was the supraclavicular region. The majority of recurrences occurred within the RT field (in-field), and no isolated out-of-field relapse was observed. In multivariate analysis, independent factors predicting higher LRR were the BLIS subtype (HR = 3.06, P = 0.02). Conclusions: Study results suggest that TNBC of the BLIS subtype is at higher risk for LRR. Immunohistochemistry-based molecular typing may serve as a prognostic biomarker to guide postmastectomy radiotherapy in patients with TNBC. New strategies are needed to improve local control rates in patients with BLIS subtype.

Clinical significance of supraclavicular lymph node (SCLN) dissection for patients with breast cancer with ipsilateral SCLN metastasis.

e13110 Background: Breast cancer with ipsilateral supraclavicular lymph node (SCLN) metastasis is defined as Ⅲc stage according to the 8th AJCC system. It is still pending whether to exert SCLN dissection except for regional radiotherapy to such patients. Methods: Breast cancer patients with ipsilateral SCLN metastasis from 2019.02 to 2024.01 in multiple centers in Hubei China, were enrolled. Patients received either SCLN radiotherapy alone or combined with SCLN dissection. All patients received standard therapy recommended by the NCCN guidelines. The primary endpoint was 5-year disease free survival (DFS), and secondary endpoints were complication rates, overall survival (OS), and quality of life scores. Results: As of 2024.01, a total of 181 patients with a median age of 51 years (28-78 years) were enrolled. 177 patients received neoadjuvant therapy and 4 patients underwent surgery followed by adjuvant therapy. The molecular subtyping composition was Luminal (HR+, HER2-, 38%), TNBC (triple negative breast cancer, HR-, HER2-, 23%), HER2+ (HR-, HER2+, 20%) and TPBC (triple positive breast cancer, HR+, HER2+, 19%). Of the 177 neoadjuvant treated-patients, 71.2% did not achieve pathological complete response (pCR). The percentage of molecular subtyping in non-pCR neoadjuvant patients was Luminal 45%, TNBC 26%, HER2+ 15%, and TPBC 14%, while those who got pCR were HER2+ 35%, TPBC 31%, Luminal 18%, and TNBC 16%. A total of 27 recurrent and/or metastatic events occurred, with 14.5% (8/55) in the experimental group (with SCLN dissection) and 15.1% (19/126) in the control group; while Luminal accounted for 13.4% (9/67), TPBC 13.9% (5/36), HER2+ 16.2% (6/37) and TNBC 17.1% (7/41). Using questionnaires, we found that both groups resulted in comparable complication rates, and quality of life scores were better in the group that did not undergo SCLN dissection. Conclusions: According to the preliminary results, we found several interesting phenomena. First, patients with SCLN metastasis had a higher percentage of HER2 overexpression, including HER2+ and TPBC, up to 39%. Second, receiving neoadjuvant therapy, TPBC and HER2+ subtypes were more likely to achieve pCR, possibly due to the use of dual-targeted agents. Third, even the median follow-up time has not yet been reached, preliminary data suggested that the recurrent and metastatic rates were comparable in both groups and four subtypes. These data seem to suggest that in patients with ipsilateral SCLN metastasis, SCLN dissection is not mandatory with effective systematic therapy and radiotherapy. In addition, for Luminal subtype, adjuvant therapy should not be taken lightly, while for HER2 overexpressing and TNBC subtypes, the necessity of intensive therapy is no longer purposely highlighted. Of course, we also look forward to the final statistical analysis of the differences in the primary endpoints to bring us a better answer. Clinical trial information: NCT03716245 .

Outcomes of very young women and adolescent (VYWAA) with breast cancer (BC) in rural and urban Saskatchewan: A population-based cohort study.

1571 Background: BC is uncommon in VYWAA (≤ 35 years) and accounts for about 1.8% of all BC. As BC screening is typically recommended for women aged 50-74 years there is a risk of delayed diagnosis of BC in VYWAA especially those with rural residence. The current study aims to assess outcomes of a cohort of VYWAA with BC in relation to their place of residence in the province of Saskatchewan over a period of 20 years. Methods: In this population-based retrospective cohort study all women ≤ 35 years with histologically documented epithelial BC during 2000-2019 were evaluated. Survival of the entire cohort and its subgroups was estimated using the Kaplan−Meier method, and the survival distribution of different groups was compared by the log rank test. A multivariate Cox proportional hazard model was performed. Various clinical and demographic variables were examined for their prognostic importance of overall survival (OS) for all stages and disease-free survival (DFS) for early-stage BC. Results: 248 eligible women with a median age of 32 years were identified, 24% were &lt;30 years of age. Of all patients, 51% had node positive disease, 7% had DCIS, 15% stage I, 42% stage II, 22% stage III and 11% had stage IV disease at initial presentation. Among them 42% had hormone receptor +, 28% had HER2 + and 23% had triple negative BC (TNBC).16% developed BC within 1-year of pregnancy. 53% were rural resident and 47% were urban resident. Significant differences were noted between the two groups regarding smoking history (42 vs. 25%), HER2+BC (35% vs. 20%) and mean platelet count (285 vs. 258). Median follow up for all women was 91 months with a total follow up period of 294 months. Median DFS of VYWAA with stage I to III disease has not reached. 10-year estimated DFS of all women was 66%. 10-year DFS for stage I and II was 73% and 75%, respectively, vs. 43% for stage III (p&lt;0.001). Median OS of entire cohort with stage 0-IV BC has not reached. 10-year OS of all VYWAA was 69%. 10 years OS of urban women was 79% compared to 65% for rural resident (p=0.041). 10-year OS of women age &gt;30 years was 74% compared to 62% for age 26-30 years and 55% for age &lt;26 (p=0.35).10 years OS of VYWAA with non-TNBC was 73% compared to 63% for with TNBC (p=0.028). On multivariate analysis for women with early-stage disease, stage III BC, HR, 3.0 (1.80-4.92) and grade III BC were significantly correlated with inferior DFS. On a multivariate analysis for OS of all VYWAA with stage 0 to IV disease, rural residence, HR, 1.75 (1.08-2.81); TNBC, HR, 2.25 (1.34-3.80), and stage IV disease, HR, 8.1 (4.72-13.94) were correlated with inferior OS. Conclusions: Very young women and adolescent with BC have a high incidence of node-positive disease and HER2+ and TNBC subtypes. TNBC and grade III disease were associated with inferior DFS in stage I-III disease whereas stage IV BC, TNBC and rural residence were correlated with inferior survival in women with stage 0-IV disease.

Unveiling the complexity: Liquid biopsy-based proteomic exploration of triple-negative breast cancer in women.

e13138 Background: This groundbreaking study places a spotlight on breast cancer in women, with a specific emphasis on the challenging triple-negative breast cancer (TNBC) subtype. Delving into the intricate world of extracellular vesicles (EVs) from TNBC-diagnosed individuals, the research meticulously compares various conditions, including healthy controls, benign tumors, recurrent tumors, and those in remission. Employing cutting-edge techniques like liquid biopsy and LC-MS/MS, the study meticulously explores the proteomic profile of serum exosomes, aiming to pinpoint diagnostic and prognostic markers in breast cancer. Methods: In the initial phase, EVs were expertly isolated and characterized from blood plasma samples exclusively from women, utilizing state-of-the-art methods such as ultracentrifugation and nanoparticle tracking analysis (NTA). Despite applying rigorous statistical criteria, the study found no significant differences in EV concentrations and sizes among the diverse groups. However, the ensuing proteomic analysis uncovered 130 proteins, with Cystatin A and Histone H2A emerging as promising biomarkers for TNBC. To validate them, the study intricately tested tumor cell lines from distinct subtypes, representing luminal, triple-negative, and HER2 overexpressed. The examination of gene and protein expression through RT-qPCR and western blotting added a layer of depth to the research, unraveling the complexity of regulatory processes within cells and demonstrating a remarkable congruence between protein levels found in the proteomics from patients’ serum and in immortalized cell lines. Results: The proteomic analysis brought to light the absence of CSTA and HIST1H2A expression in benign tumor patients, varied levels in malignant tumor patients, and a substantial increase in TNBC patients pre-mastectomy. Validating these findings through western blotting further accentuated the potential of these proteins as distinguishing factors. Conclusions: In conclusion, this pioneering study not only underscores the immense potential of liquid biopsy-based proteomic analysis in identifying crucial diagnostic and prognostic markers in breast cancer but also sheds light on the intricate nuances of the challenging TNBC subtype. Our findings unveil valuable insights that pave the way for future personalized treatment strategies, marking a significant stride forward in breast cancer research.

Tolerance and safety of adjuvant metronomic capecitabine in Indian patients with non-metastatic triple negative breast cancer (TNBC): An institutional experience.

e12530 Background: Triple-negative breast cancer (TNBC) subtype has a high risk of recurrence and overall poorer survival after standard treatment. SYSUCC-001 study presented in ASCO 2020 reported an increased disease-free survival after one year of metronomic capecitabine in operable TNBC patients after completion of local therapy. As per our clinical experience in metastatic breast cancer, many Indian patients are not able to tolerate capecitabine for longer duration. Hence, we wanted to assess the tolerance and safety of one year of daily dosing of capecitabine in our patients with Non-Metastatic TNBC. Methods: We performed a retrospective analysis of non-metastatic TNBC patients receiving adjuvant capecitabine 650 mg /m2 twice daily continuously for one year who took treatment from June 2020 to August 2022. The data extracted included patient socio-demographics, capecitabine information, side effects, and capecitabine treatment changes (dose reductions and dose interruptions). Statistical analysis was conducted using SPSS, version 24. Results: We analyzed 90 patients, out of which majority (62%) were stage II. Median age of the cohort was 48 years. Germline data was available for 64 patients, out which 8 patients were BRCA 1 positive and 8 patients had a variant of undetermined significance. Median duration of capecitabine in our patients was 230 days (IQR: 10 - 360). Twenty-six (28.8%) patients underwent dose reduction and 15 (16.6%) had reported grade 3 toxicity. Mean dose of capecitabine received was 535 mg / m2 twice daily. Treatment was interrupted due to toxicity in 20 (22%) of patients. The most common capecitabine-induced toxicity was hand foot syndrome, which was also the most common reason for dose reduction and treatment interruption. Dihydropyrimidine dehydrogenase (DPD) mutation status was known for 38 patients out of which only one (2.6%) was found to have DPD deficiency. Incidence of grade 3 toxicity was observed to be less in patients with age less than 50 years, ECOG performance status 0-1 and absence of comorbidities. Two-year disease free survival (DFS) and overall survival (OS) was estimated to be 79.3% and 80% respectively. Most common site of metastases was reported to be brain followed by lung. Conclusions: Continuous metronomic dosing of adjuvant capecitabine for 1 year is fairly well tolerated in Indian patients with non-metastatic TNBC, but may still require dose reduction in some patients due to toxicity.

Genomic analysis of the tumor microenvironment in Asian and Native Hawaiian and Pacific Islander patients with triple negative breast cancer.

e12644 Background: Triple negative breast cancer (TNBC) accounts for approximately 10- 20% of breast cancer cases and has the worst overall survival and prognosis compared to other subtypes. Unlike other subtypes, patients with TNBC are responsive to neoadjuvant therapy. A higher percent of stromal tumor infiltrating lymophocytes (sTILs) in the tumor microenvironment of TNBC correlates with an improved prognosis. Previous studies demonstrate that Native Hawaiians and Pacific Islanders (NHPIs) and Asians have equivocal percent of sTILs. Yet NHPIs have a higher mortality rate at 24.9% compared to Asians at 11%. Our study aims to molecularly characterize the tumor microenvironment in a diverse population of patients with TNBC who received neoadjuvant therapy. Methods: Retrospective chart review was conducted on 12 Asians and 12 NHPI patients with early stage TNBC from 2015 to 2022 from a medical oncology clinic within the Hawai’i Pacific Health system. Patient data collected include age at diagnosis of breast cancer, histology, BMI, clinical stage, sTILs, residual cancer burden, neoadjuvant treatment, and pathologic complete response. Core biopsy samples were processed and analyzed using the nCounter Breast Cancer 360 Panel. Further analysis was obtained using the nSolver Advanced Analysis Module. Results: Patient characteristics are listed in the table. Most patients had the basal-like immunosuppressed TNBC subtype. Among differentially expressed genes between races, 31 genes were statistically significant. NHPIs expressed more IL12RB2 and MYC, and Asians expressed more FGFR4 and MLPH. Among responders compared to non-responders, 5 genes were statistically significant. Responders expressed more STC1 and PTGER3, and non-responders expressed more CRAYAB, TMPRSS2, and CHAD. Among old and young patients, 132 genes were statistically significant. Older patients expressed more FUT3 and CKMT1, and younger patients expressed more MMP7 and MIA. Conclusions: In this pilot study, the molecular and genetic differences suggest that the tumor microenvironment may play a role in treatment outcomes between NHPIs and Asians. Further analysis will be conducted to determine the differences in immune cell infiltration. [Table: see text]

Triple Negative Breast Cancer: Molecular Subtype-Specific Immune Landscapes with Therapeutic Implications.

Triple Negative Breast Cancer (TNBC) is characterized by distinct molecular subtypes with unique biological and clinical features. This systematic review aimed to identify articles examining the differences in the tumor immune microenvironment (TIME) across different TNBC molecular subtypes. Six studies meeting inclusion criteria were analyzed, utilizing gene expression profiling and bioinformatic analyses to classify TNBC samples into molecular subtypes, as well as immunohistochemistry and cell deconvolution methods to characterize the TIME. Results revealed significant heterogeneity in immune cell composition among TNBC subtypes, with the immunomodulatory (IM) subtype demonstrating robust immune infiltration, composed mainly of adaptive immune cells along with an increased density of CTLA-4+ and PD-1+ TILs, high PD-L1 tumor cell expression, and upregulation of FOXP3+ Tregs. A more immunosuppressive TIME with a predominance of innate immune cells and lower levels of tumor-infiltrating lymphocytes (TILs) was observed in luminal androgen receptor (LAR) tumors. In mesenchymal stem-like (MSL) tumors, the TIME was mainly composed of innate immune cells, with a high number of M2 tumor-associated macrophages (TAMs), while the BL and M tumors displayed poor adaptive and innate immune responses, indicating an "immune-cold" phenotype. Differential activation of signaling pathways, genomic diversity, and metabolic reprogramming were identified as contributors to TIME heterogeneity. Understanding this interplay is crucial for tailoring therapeutic strategies, especially regarding immunotherapy.

Genomic characterization reveals distinct mutational landscapes and therapeutic implications between different molecular subtypes of triple-negative breast cancer

Triple-negative breast cancer (TNBC) has high heterogeneity, poor prognosis, and limited treatment success. Recently, an immunohistochemistry-based surrogate classification for the “Fudan University Shanghai Cancer Center (FUSCC) subtyping” has been developed and is considered more suitable for clinical application. Seventy-one paraffin-embedded sections of surgically resected TNBC were classified into four molecular subtypes using the IHC-based surrogate classification. Genomic analysis was performed by targeted next-generation sequencing and the specificity of the subtypes was explored by bioinformatics, including survival analysis, multivariate Cox regression, pathway enrichment, Pyclone analysis, mutational signature analysis and PHIAL analysis. AKT1 and BRCA1 mutations were identified as independent prognostic factors in TNBC. TNBC molecular subtypes encompass distinct genomic landscapes that show specific heterogeneities. The luminal androgen receptor (LAR) subtype was associated with mutations in PIK3CA and PI3K pathways, which are potentially sensitive to PI3K pathway inhibitors. The basal-like immune-suppressed (BLIS) subtype was characterized by high genomic instability and the specific possession of signature 19 while patients in the immunomodulatory (IM) subtype belonged to the PD-L1 ≥ 1% subgroup with enrichment in Notch signaling, suggesting a possible benefit of immune checkpoint inhibitors and Notch inhibitors. Moreover, mesenchymal-like (MES) tumors displayed enrichment in the receptor tyrosine kinase (RTK)-RAS pathway and potential sensitivity to RTK pathway inhibitors. The findings suggest potential treatment targets and prognostic factors, indicating the possibility of TNBC stratified therapy in the future.