Triple-negative Tumors Research Articles

Neoadjuvant chemotherapy for breast cancer in Italy: A Senonetwork analysis of 37,215 patients treated from 2017 to 2022

BackgroundAdoption of neoadjuvant chemotherapy (NACT) in the “real world” has been poorly investigated. Aim of this study was to examine the rate of NACT in Italy, trends over time and determinants of therapeutic choices. MethodsSenonetwork, the recognized network of Breast Centers in Italy, has developed a voluntary national data warehouse with the aim to monitor and improve treatments quality. A retrospective analysis was conducted among 58,661 breast cancer (BC) patients treated between 2017 and 2022 by 24 high-volume Breast Centers participating in the project. ResultsAfter subset exclusion, 37,215 primary BC patients were analysed, 32,933 underwent primary-breast-surgery and 4,282 underwent NACT. From 2017 to 2022, the overall NACT incidence increased particularly for HR-/HER2+, Triple-Negative, and HR+/HER2+ BC (p < 0.001). In cN + patients the recommendation to axillary lymph-node dissection after NACT decreased over time along with an increase of <4 lymph-nodes removed (p < 0.001). Immediate breast reconstruction and indication for nipple sparing mastectomy increased significantly over time (OR = 1.10, p = 0.011 and OR 1.14, p < 0.001, respectively). On multivariate analysis, there was a trend towards an increased adoption of conservative treatment for HR-/HER2+ (p = 0.01) and Triple Negative tumors (p = 0.06). Implementation of NACT varied significantly among Breast-Centers from 3.8 to 17.7 % (p < 0.001). ConclusionThe impact of NACT on the subsequent surgical management is substantial and continues to evolve over time, resulting in less-extensive surgery. Even among high-volume Centers NACT implementation rate is still highly variable. Although we registered a significant increase in its use during the study period, these results need to be further improved.

Association Between Smoking with a Molecular Profile of Breast Cancer

Background: Female breast cancer is one of the causes of the highest cancer mortality and morbidity in the world. It is already known that there is a strong association between smoking and breast cancer. However, the association between smoking and tumor severity is not very clear. The objective of this study was to assess the severity of the breast tumor, using the tumor's molecular classification as a tool according to its immunohistochemical profile in smoking and non-smoking women. Methods: This is a longitudinal study in which 208 women with a diagnosis of breast cancer were followed for 17 months, 80 of whom were smokers and all underwent anatomopathological diagnosis by core biopsy and subsequent immunohistochemistry, followed by treatment indicated according to the type and the clinical staging of the tumor. The severity of the tumor was assessed by its molecular classification according to its immunohistochemical profile. Results: Smoking was associated with higher mortality. The tumor with the most severe immunohistochemical profile was found in younger smokers. 19.7% of smokers had a triple negative tumor and 10% of non-smokers. The age of female smokers with triple negative was 48.2 years and of non-smoking women was 52.6 years (p = 0.005). In 17 months of follow-up, mortality among smokers was 39.5% and for nonsmokers, 20%. Survival was statistically significantly lower among the group of smokers (p=0.01). Conclusion: smoking is associated with greater breast cancer severity, risk for cancer severity was OR 5.5 times higher for the smoking group survival was statistically significantly lower among the group of smokers

Ataxia telangiectasia-mutated rs56009889 and risk of common cancers.

A polymorphic variant in the ataxia telangiectasia-mutated (ATM) gene, rs56009889, was recently associated with an increased risk of lung cancer. We studied the role of this variant in the etiology of other cancers. Data from three population-based case-control studies of colon, breast, and lung cancer were used. Participants in these studies (4517 cases, 3383 controls) underwent a genome-wide association study using 500K Illumina OncoArray. The frequency of the AG/AA genotypes differed between Ashkenazi (4.6%) and Sephardi (0.2%) Jews (P < 0.001). AG/AA frequency was significantly higher in Ashkenazi lung cancer (11.9%) than in controls (2.8%) [adjusted odds ratio (OR) = 5.4]. Females had a higher risk than males (OR = 12.8 versus 3.5). The adjusted OR for colorectal cancer was 1.40 [95% confidence interval (CI) = 1.01-2.0, P = 0.045] and for breast cancer was 1.43 (95% CI = 1.01-2.04, P = 0.046). Never-smokers variant carriers were at higher risk of lung and colon, but not breast, cancer. Cases with the AG/AA genotype had lower mean age at diagnosis, but this difference was significant only for breast cancer (-3.2 years, P = 0.007). No associations were observed with overall survival. Among the breast cancer subjects, the OR for having triple-negative tumors was 0.45 for AG/AA versus GG genotype (95% CI = 0.2-0.9, P = 0.02). We confirm the strong association between ATM rs56009889 and lung cancer risk in Ashkenazi Jews and report a mild association with the risk of breast cancer and colorectal cancer.

Respective contribution of baseline clinical data, tumour metabolism and tumour blood-flow in predicting pCR after neoadjuvant chemotherapy in HER2 and Triple Negative breast cancer

Background:The aim of this study is to investigate the added value of combining tumour blood flow (BF) and metabolism parameters, including texture features, with clinical parameters to predict, at baseline, the pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) in patients with newly diagnosed breast cancer (BC).Methods:One hundred and twenty-eight BC patients underwent a 18F-FDG PET/CT before any treatment. Tumour BF and metabolism parameters were extracted from first-pass dynamic and delayed PET images, respectively. Standard and texture features were extracted from BF and metabolic images. Prediction of pCR was performed using logistic regression, random forest and support vector classification algorithms. Models were built using clinical (C), clinical and metabolic (C+M) and clinical, metabolic and tumour BF (C+M+BF) information combined. Algorithms were trained on 80% of the dataset and tested on the remaining 20%. Univariate and multivariate features selections were carried out on the training dataset. A total of 50 shuffle splits were performed. The analysis was carried out on the whole dataset (HER2 and Triple Negative (TN)), and separately in HER2 (N=76) and TN (N=52) tumours.Results:In the whole dataset, the highest classification performances were observed for C+M models, significantly (p-value<0.01) higher than C models and better than C+M+BF models (mean balanced accuracy of 0.66, 0.61, and 0.64 respectively). For HER2 tumours, equal performances were noted for C and C+M models, with performances higher than C+M+BF models (mean balanced accuracy of 0.64, and 0.61 respectively). Regarding TN tumours, the best classification results were reported for C+M models, with better performances than C and C+M+BF models but not significantly (mean balanced accuracy of 0.65, 0.63, and 0.62 respectively).Conclusion:Baseline clinical data combined with global and texture tumour metabolism parameters assessed by 18F-FDG PET/CT provide a better prediction of pCR after NAC in patients with BC compared to clinical parameters alone for TN, and HER2 and TN tumours together. In contrast, adding BF parameters to the models did not improve prediction, regardless of the tumour subgroup analysed.

Participation in a High-Risk Program Is Associated with a Diagnosis of Earlier-Stage Disease Among Women at Increased Risk for Breast Cancer Development.

High-risk programs provide recommendations for surveillance/risk reduction for women at elevated risk for breast cancer development. This study evaluated the impact of high-risk surveillance program participation on clinicopathologic breast cancer features at the time of diagnosis. Women followed in the authors' high-risk program (high-risk cohort [HRC]) with a diagnosis of breast cancer from January 2015 to June 2021 were identified and compared with the general population of women undergoing breast cancer surgery at Memorial Sloan Kettering Cancer Center (MSK; general cohort [GC]) during the same period. Patient and tumor factors were collected. Clinicopathologic features were compared between the two cohorts and in a subset of women with a family history of known BRCA mutation. The study compared 255 women in the HRC with 9342 women in the GC. The HRC patients were slightly older and more likely to be white and have family history than the GC patients. The HRC patients also were more likely to present with DCIS (41 % vs 23 %; p < 0.001), to have smaller invasive tumors (pT1: 100 % vs 77 %; p < 0.001), and to be pN0 (95 % vs 81 %; p < 0.001). The HRC patients had more invasive triple-negative tumors (p = 0.01) and underwent less axillary surgery (p < 0.001), systemic therapy (p < 0.001), and radiotherapy (p = 0.002). Among those with a known BRCA mutation, significantly more women in the HRC underwent screening mammography (75 % vs 40 %; p < 0.001) or magnetic resonance imaging (MRI: 82 % vs 9.9 %; p < 0.001) in the 12 months before diagnosis. Women followed in a high-risk screening program have disease diagnosed at an earlier stage and therefore require less-intensive breast cancer treatment than women presenting to a cancer center at the time of diagnosis. Identification of high-risk women and implementation of increased surveillance protocols are vital to improving outcomes.

Prognostic potential of CUL3 ligase with differential roles in luminal A and basal type breast cancer tumors

Breast cancer is a prevalent and significant cause of mortality in women, and manifests as six molecular subtypes. Its further histologic classification into non-invasive ductal or lobular carcinoma (DCIS) and invasive carcinoma (ILC or IDC) underscores its heterogeneity. The ubiquitin–proteasome system plays a crucial role in breast cancer, with inhibitors targeting the 26S proteasome showing promise in clinical treatment. The Cullin-RING ubiquitin ligases, including CUL3, have direct links to breast cancer. This study focuses on CUL3 as a potential biomarker, leveraging high-throughput sequencing, gene expression profiling, experimental and data analysis tools. Through comprehensive analysis using databases like GEPIA2 and UALCAN, as well as TCGA datasets, CUL3's expression and its association with prognostic values were assessed. Additionally, the impact of CUL3 overexpression was explored in MCF-7 and MDA-MB-231 breast cancer cell lines, revealing distinct differences in molecular and phenotypic characteristics. We further profiled its expression and localization in breast cancer tissues identifying prominent differences between luminal A and TNBC tumors. Conclusively, CUL3 was found to be associated with cell cycle progression, and DNA damage response, exhibiting diverse roles depending on the tumor's molecular type. It exhibits a tendency to act as an oncogene in triple-negative tumors and as a tumor suppressor in luminal A types, suggesting a potential significance in breast cancer progression and therapeutic directions.

Selective delivery of neuropeptide Y peptides linked to magnetic particles for hyperthermia application

Although standard treatments against cancer have achieved significant effects in growth inhibition and tumor elimination, they still cause severe side effects. Therefore, the specific targeting of cancer cells without affecting healthy tissue is currently an important desire in cancer therapy. Cell surface receptors that bind peptides are often overexpressed on tumor cells and can therefore be considered promising targets for selective tumor therapy. Here, we report on the use of neuropeptide Y receptor 1 (Y1R) specific delivery of magnetic nanoparticles. The Y1R is overexpressed in breast cancer cells including triple negative type tumors. Magnetic particles allow for hyperthermia applications for the treatment of malignant cells and have been proposed for biomedical use for several years. One of the limitations so far was selectivity and intracellular uptake into tumor cells. By using specifically modified nanoparticles and site-specific conjugation to selective peptides specific uptake into Y1R positive cells is demonstrated here.

Turning Waste into Wealth: A Potent Sono-Immune Strategy Based on Microcystis.

Currently, sonodynamic therapy (SDT) has limited therapeutic outcomes and immune responses, highlighting the urgent need for enhanced strategies that can stimulate robust and long-lasting antitumor effects. Microcystis, a notorious microalga, reveals the possibility of mediating SDT owing to the presence of gas vesicles (GVs) and phycocyanin (PC). Herein, a nontoxic strain of Microcystis elabens (labeled Me) is developed as a novel agent for SDT because it generates O2 under red light (RL) illumination, while GVs and PC act as cavitation nuclei and sonosensitizers, respectively. Moreover, algal debris is released after ultrasound (US) irradiation, which primes the Toll-like receptor pathway to initiate a cascade of immune responses. This sono-immune strategy inhibits CT26 colon tumor growth largely by promoting dendritic cell (DC) maturation and cytotoxic T-cell activation. After combination with the immune checkpoint blockade (ICB), the therapeutic outcome is further amplified, accompanied by satisfactory abscopal and immune memory effects; the similar potency is proven in the "cold" 4T1 triple-negative breast tumor. In addition, Me exhibits good biosafety without significant acute or chronic toxicity. Briefly, this study turns waste into wealth by introducing sono-immunotherapy based on Microcystis that achieved encouraging therapeutic effects on cancer, which is expected to be translated into the clinic.

Detailed Profiling of the Tumor Microenvironment in Ethnic Breast Cancer, Using Tissue Microarrays and Multiplex Immunofluorescence.

Breast cancer poses a global health challenge, yet the influence of ethnicity on the tumor microenvironment (TME) remains understudied. In this investigation, we examined immune cell infiltration in 230 breast cancer samples, emphasizing diverse ethnic populations. Leveraging tissue microarrays (TMAs) and core samples, we applied multiplex immunofluorescence (mIF) to dissect immune cell subtypes across TME regions. Our analysis revealed distinct immune cell distribution patterns, particularly enriched in aggressive molecular subtypes triple-negative and HER2-positive tumors. We observed significant correlations between immune cell abundance and key clinicopathological parameters, including tumor size, lymph node involvement, and patient overall survival. Notably, immune cell location within different TME regions showed varying correlations with clinicopathologic parameters. Additionally, ethnicities exhibited diverse distributions of cells, with certain ethnicities showing higher abundance compared to others. In TMA samples, patients of Chinese and Caribbean origin displayed significantly lower numbers of B cells, TAMs, and FOXP3-positive cells. These findings highlight the intricate interplay between immune cells and breast cancer progression, with implications for personalized treatment strategies. Moving forward, integrating advanced imaging techniques, and exploring immune cell heterogeneity in diverse ethnic cohorts can uncover novel immune signatures and guide tailored immunotherapeutic interventions, ultimately improving breast cancer management.

Iridium(III) carbene complexes as potent girdin inhibitors against metastatic cancers

Many cancer-driving protein targets remain undruggable due to a lack of binding molecular scaffolds. In this regard, octahedral metal complexes with unique and versatile three-dimensional structures have rarely been explored as inhibitors of undruggable protein targets. Here, we describe antitumor iridium(III) pyridinium-N-heterocyclic carbene complex 1a, which profoundly reduces the viability of lung and breast cancer cells as well as cancer patient-derived organoids at low micromolar concentrations. Compound 1a effectively inhibits the growth of non-small-cell lung cancer and triple-negative breast cancer xenograft tumors, impedes the metastatic spread of breast cancer cells, and can be modified into an antibody-drug conjugate payload to achieve precise tumor delivery in mice. Identified by thermal proteome profiling, an important molecular target of 1a in cellulo is Girdin, a multifunctional adaptor protein that is overexpressed in cancer cells and unequivocally serves as a signaling hub for multiple pivotal oncogenic pathways. However, specific small-molecule inhibitors of Girdin have not yet been developed. Notably, 1a exhibits high binding affinity to Girdin with a Kd of 1.3 μM and targets the Girdin-linked EGFR/AKT/mTOR/STAT3 cancer-driving pathway, inhibiting cancer cell proliferation and metastatic activity. Our study reveals a potent Girdin-targeting anticancer compound and demonstrates that octahedral metal complexes constitute an untapped library of small-molecule inhibitors that can fit into the ligand-binding pockets of key oncoproteins.

Tumour-specific phosphorylation of serine 419 drives alpha-enolase (ENO1) nuclear export in triple negative breast cancer progression

BackgroundThe glycolytic enzyme alpha-enolase is a known biomarker of many cancers and involved in tumorigenic functions unrelated to its key role in glycolysis. Here, we show that expression of alpha-enolase correlates with subcellular localisation and tumorigenic status in the MCF10 triple negative breast cancer isogenic tumour progression model, where non-tumour cells show diffuse nucleocytoplasmic localisation of alpha-enolase, whereas tumorigenic cells show a predominantly cytoplasmic localisation. Alpha-enolase nucleocytoplasmic localisation may be regulated by tumour cell-specific phosphorylation at S419, previously reported in pancreatic cancer.ResultsHere we show ENO1 phosphorylation can also be observed in triple negative breast cancer patient samples and MCF10 tumour progression cell models. Furthermore, prevention of alpha-enolase-S419 phosphorylation by point mutation or a casein kinase-1 specific inhibitor D4476, induced tumour-specific nuclear accumulation of alpha-enolase, implicating S419 phosphorylation and casein kinase-1 in regulating subcellular localisation in tumour cell-specific fashion. Strikingly, alpha-enolase nuclear accumulation was induced in tumour cells by treatment with the specific exportin-1-mediated nuclear export inhibitor Leptomycin B. This suggests that S419 phosphorylation in tumour cells regulates alpha-enolase subcellular localisation by inducing its exportin-1-mediated nuclear export. Finally, as a first step to analyse the functional consequences of increased cytoplasmic alpha-enolase in tumour cells, we determined the alpha-enolase interactome in the absence/presence of D4476 treatment, with results suggesting clear differences with respect to interaction with cytoskeleton regulating proteins.ConclusionsThe results suggest for the first time that tumour-specific S419 phosphorylation may contribute integrally to alpha-enolase cytoplasmic localisation, to facilitate alpha-enolase’s role in modulating cytoskeletal organisation in triple negative breast cancer. This new information may be used for development of triple negative breast cancer specific therapeutics that target alpha-enolase.

Factors delaying non-metastatic breast cancer adjuvant therapy and impact on prognosis in a cohort of Brazilian women.

To identify factors associated with delays in beginning adjuvant therapy and prognosis impacts on non-metastatic breast cancer patients. This assessment comprised a prospective cohort study concerning breast cancer patients treated at a public oncology centre. A time interval of ≥60 days between surgery and the beginning of the first adjuvant treatment was categorised as a delay. Factors associated with delays were evaluated through logistic regression analysis and the prognosis effects were assessed by a Cox regression analysis. The median time interval between surgery and the first adjuvant treatment for the 401 women included in this study was of 57.0 days (37.0-93.0). Independent factors associated with delays comprised not presenting an overexpression of the HER-2 protein, not having undergone neoadjuvant chemotherapy, and having undergone chemotherapy or other therapeutic modalities other than hormone therapy and chemotherapy as the first adjuvant treatment. Delays did not affect recurrence, distant metastasis, or death risks. Factors associated with recurrence and distant metastasis risks comprised a clinical staging ≥2B, having undergone neoadjuvant chemotherapy, presenting the luminal molecular subtype B and triple-negative tumours, and having children. Factors associated with death comprised triple-negative molecular tumours and neoadjuvant chemotherapy. Delays in beginning adjuvant treatment did not affect the prognosis of non-metastatic breast cancer patients. Clinical and treatment-related factors, on the other hand, were associated with delays, and recurrence, distant metastasis, and death risks.

Correlation of RANK and RANKL with mammographic density in primary breast cancer patients

PurposeThe receptor activator of nuclear factor kappa B (RANK) and its ligand (RANKL) have been shown to promote proliferation of the breast and breast carcinogenesis. The objective of this analysis was to investigate whether tumor-specific RANK and RANKL expression in patients with primary breast cancer is associated with high percentage mammographic density (PMD), which is a known breast cancer risk factor.MethodsImmunohistochemical staining of RANK and RANKL was performed in tissue microarrays (TMAs) from primary breast cancer samples of the Bavarian Breast Cancer Cases and Controls (BBCC) study. For RANK and RANKL expression, histochemical scores (H scores) with a cut-off value of > 0 vs 0 were established. PMD was measured in the contralateral, non-diseased breast. Linear regression models with PMD as outcome were calculated using common predictors of PMD (age at breast cancer diagnosis, body mass index (BMI) and parity) and RANK and RANKL H scores. Additionally, Spearman rank correlations (ρ) between PMD and RANK and RANKL H score were performed.ResultsIn the final cohort of 412 patients, breast cancer-specific RANK and RANKL expression was not associated with PMD (P = 0.68). There was no correlation between PMD and RANK H score (Spearman’s ρ = 0.01, P = 0.87) or RANKL H score (Spearman’s ρ = 0.04, P = 0.41). RANK expression was highest in triple-negative tumors, followed by HER2-positive, luminal B-like and luminal A-like tumors, while no subtype-specific expression of RANKL was found.ConclusionResults do not provide evidence for an association of RANK and RANKL expression in primary breast cancer with PMD.

Simultaneous Protonation and Metalation of a Porphyrin Covalent Organic Framework Enhance Photodynamic Therapy.

Covalent organic frameworks (COFs) have been explored for photodynamic therapy (PDT) of cancer, but their antitumor efficacy is limited by excited state quenching and low reactive oxygen species generation efficiency. Herein, we report a simultaneous protonation and metalation strategy to significantly enhance the PDT efficacy of a nanoscale two-dimensional imine-linked porphyrin-COF. The neutral and unmetalated porphyrin-COF (Ptp) and the protonated and metalated porphyrin-COF (Ptp-Fe) were synthesized via imine condensation between 5,10,15,20-tetrakis(4-aminophenyl)porphyrin and terephthalaldehyde in the absence and presence of ferric chloride, respectively. The presence of ferric chloride generated both doubly protonated and Fe3+-coordinated porphyrin units, which red-shifted and increased the Q-band absorption and disrupted exciton migration to prevent excited state quenching, respectively. Under light irradiation, rapid energy transfer from protonated porphyrins to Fe3+-coordinated porphyrins in Ptp-Fe enabled 1O2 and hydroxyl radical generation via type II and type I PDT processes. Ptp-Fe also catalyzed the conversion of hydrogen peroxide to hydroxy radical through a photoenhanced Fenton-like reaction under slightly acidic conditions and light illumination. As a result, Ptp-Fe-mediated PDT exhibited much higher cytotoxicity than Ptp-mediated PDT on CT26 and 4T1 cancer cells. Ptp-Fe-mediated PDT afforded potent antitumor efficacy in subcutaneous CT26 murine colon cancer and orthotopic 4T1 murine triple-negative breast tumors and prevented metastasis of 4T1 breast cancer to the lungs. This work underscores the role of fine-tuning the molecular structures of COFs in significantly enhancing their PDT efficacy.

Glucagon-like peptide-1 (GLP-1) agonist use and weight change among patients with breast cancer.

10607 Background: Elevated body mass index (BMI) and post-diagnosis weight gain increase the risk of breast cancer recurrence and all-cause mortality. Chemotherapy and endocrine therapy can worsen metabolic dysfunction and are associated with weight gain. GLP-1 agonists mimic the action of endogenous GLP-1 and stimulate insulin secretion, delay gastric emptying, and promote satiety. In addition to diabetes treatment, several of these agents induce substantial (8-15%) weight loss and are indicated for obesity weight management. The efficacy of GLP-1 agonists during or after breast cancer treatment is unclear. Methods: Patients with breast cancer and prescribed a GLP-1 agonist from 2015-2023 with follow-up weight data (pre- and on/post-GLP-1 agonist) were included in this retrospective cohort study. A linear mixed effects model with a random intercept for baseline patient weight was used to assess mean weight change at each available follow-up timepoint. Relative weight change from baseline to approximately 12 months after GLP-1 agonist initiation was also computed and a multivariable linear regression was used to assess the association of baseline covariates with relative weight change. Results: 75 patients were included; median age was 52 (range 27-74), 4 (5%) had carcinoma in situ, 64 (85%) had stage I – III, and 4 (5%) had stage IV breast cancer. 62 (83%) had hormone receptor-positive tumors; 14 (19%) had HER2-positive and 8 (11%) had triple negative tumors. 40 (53%) received an aromatase inhibitor concurrently with GLP-1 agonist whereas 3 (4%) received tamoxifen concurrently. Chemotherapy was administered to 56 (75%), and 44 (59%) received radiation. 59 (79%) had a diagnosis of diabetes. Median time from breast cancer diagnosis to GLP-1 agonist prescription was 4.3 years (range -4.4 to 29.5). Median weight at breast cancer diagnosis was 85 kg (range 52-163), median BMI was 32 kg/m2 (range 20-53). Median weight upon GLP-1 agonist initiation was 90 kg (range 58-151) and median BMI was 34 kg/m2 (range 23-50). Median duration of GLP-1 agonist use was 20 months (range 6-111). At 12 months after GLP-1 agonist initiation, mean relative weight change was -5% (SD 6%). Mean weight change from GLP-1 agonist initiation was -2.8 kg (95% CI -0.9 to -4.7) at 6 months, -4.2 kg (95% CI -2.1 to -6.2) at 12 months, and -6.2 kg (95% CI -3.7 to -8.7) post-GLP-1 agonist treatment. Baseline BMI, concurrent anti-estrogen therapy, duration of GLP-1 agonist therapy, and comorbid diabetes were not associated with relative weight change in multivariate models. Conclusions: The use of GLP-1 agonists in this cohort of patients treated for breast cancer was efficacious and associated with modest (5%) weight loss. Based on this observed activity, prospective trials are warranted.

Effect of tumorspheres cultured from circulating cancer stem cells on the innate checkpoint CD47 in patients with breast cancer.

e13113 Background: Circulating cancer cells, and in particular their very rare subpopulation, circulating cancer stem cells (cCSCs), are responsible for recurrence and metastasis. The exact role of cCSCs in escape of cancer from immunosurveillance is still unknown, but recent studies reported that increased expression of CD47 enable cancer cells to evade phagocytosis by macrophages and promote the cancer stem cell phenotype. Understanding the mechanisms behind this CD47 overexpression in cancer stem cells is critical for developing more effective immunotherapy. Therefore, in the current study, we evaluated the incidence and clinical relevance of tumorspheres cultured from cCSCs expressing CD47 in breast cancer patients. Methods: 110 patients with breast cancer in different stages of disease were included in this study. The determination of cCSCs was performed using the sphere-forming assay. Additionally, anti-CD47 antibody staining was applied to examine CD47 expression on breast tumorspheres. Results: We have developed an innovative in vitro platform for detection of cCSCs from peripheral blood of cancer patients. The number of tumorspheres was associated with disease progression and aggressiveness of primary tumor. Patients with metastatic disease had statistically more tumorspheres as compared to patients without metastasis (30 vs 10/100µl blood, p&lt;0.05). Patients with multiple metastasis had more tumorspheres compared to patients with single metastases (60 vs 30/100µl blood, p&lt;0.05). CD47 was highly expressed in tumorspheres, which are enriched from circulating cancer stem cells and associated with triple-negative tumors. We also observed high heterogeneity of CD47 expression between the tumorspheres of a patient and between the patients. Conclusions: The number of tumorspheres cultured from peripheral blood directly reflects aggressiveness and proliferation capacity of primary tumor. The presence of tumorspheres with high expression of CD47 might suggest their immunoregulatory potential. Better understanding of the interaction between cCSCs and tumor immunology may improve outcome especially in high-risk patients in part by attacking cCSCs and disinhibiting innate immunity.

Receptor expression testing of the synchronous axillary nodal metastasis in early-stage breast cancer: Comparison of primary tumor and its draining nodes.

e12542 Background: Early stage (Stage I-III) human epidermal receptor -2 (HER2) positive and triple negative breast cancers (TNBC) tend to behave more aggressively than hormone positive breast cancers with higher and earlier incidences of recurrences. Oftentimes, testing for receptor subtypes is done only on the primary tumor and not on the synchronous axillary metastasis, with the assumption that the axillary metastasis is congruous to the primary lesion. Current guidelines also do not specify a requisite to do this testing. Information about the receptor expression types is fundamental for the treatment of breast cancer. We aimed to determine if there is significant discordance between the primary and ipsilateral axillary metastasis in early-stage breast cancer. Methods: We conducted a retrospective analysis via electronic medical record review of a large institutional database from 2008 to 2020. Sample for this study included all patients with a diagnosis of early-stage breast cancer (Stage I - III) with triple negative or HER2 positive tumors. Data on demographics, comorbidities, receptor status, staging, and mortality were collected. Results: Electronic charts from 448 patients were reviewed. 140 patients had axillary node positive disease. 40 (29%) of the 140 patients underwent testing for receptors subtypes on both primary and axillary nodal metastasis. 8 (20%) of the 40 patients had discordance in their receptor subtype expressed in their respective axillary nodal metastasis. 32 (80%) of the 40 patients had axillary receptor expression congruous to the primary tumor. At the time of our review, there was no statistically significant mortality between discordant compared to concordant group (13% vs 20%; p=0.54). 2 patients were lost to follow up. Conclusions: Our data suggests that one in every five axillary metastatic breast cancers can have receptor subtypes discordant compared to the receptors expressed on the primary tumor. Knowledge about any such discordance between the primary and respective axillary metastasis has a consequential impact on the treatment approach for early-stage breast cancer. This is especially true if the patient’s nodal metastatic lesions indeed prove HER2 receptor positivity or do not express any receptors (TNBC). Consequently, patients may be being deprived of benefits from advances in treatment of these cancers, such as targeted therapies towards HER2 receptor, hormonal treatments when indicated, or the utilization of neoadjuvant chemotherapy. A strong case can be thus made to revise current standards to include receptor testing on all primary and synchronous axillary metastasis. Further testing is needed to validate our findings.

The role of stress in modulating AIPB expression and estradiol synthesis in triple-negative breast tumors.

e13146 Background: In the United States, invasive breast cancer affects 1 in 8 women during their lifetime, with over 3.8 million individuals living as survivors. Breast cancers vary, with some being hormone-responsive and categorized on the presence or absence of estrogen (ER), progesterone (PR), and HER2 receptors. While targeted therapies exist for Estrogen Receptor positive (Er+) and Progesterone Receptor positive (PR+) cancers, triple-negative breast cancer (TNBC), which lacks all three receptors, affects about 15% of patients and is unresponsive to effective molecular treatments. Only a fraction of the cases respond to chemotherapy which emphasizes a need for new prognostic markers and treatments. Aromatase is the key enzyme in converting testosterone to estradiol which plays a crucial role in tumor growth, especially after menopause. Our research lab has identified the “Aromatase Interacting Partner in Breast or AIPB, whose overexpression inhibits aromatase, leading to a reduction in estradiol levels. However, in triple-negative breast cancer, there is an increase in AIPB expression when compared to ER+/PR+/Her2- breast tumors or unaffected women. This devastating prognosis and low survival rates can contribute to a considerable amount of stress in the diagnosed patients, in turn leading to an increase in cortisol production. Our hypothesis suggests that this stress or increase in cortisol could alter AIPB production in the tumorigenic cells which could potentially lead to a decrease in estradiol synthesis. Methods: Stress stimulation was achieved in a lab setting by subjecting engineered triple-negative breast cancer cells, capable of conditional AIPB overexpression upon tetracycline addition, to a 42 °C heat shock for various durations (0,15, 30, 45 minutes). Results: Following the 45 minutes of stress, MDA-MMD-231 cells exhibited a significant reduction in estradiol levels, decreasing from 160ng/ml to 100ng/ml. MDA-MD-231 cells engineered to overexpress AIPB produced only 62ng/ml of estradiol, marking an 18.75% decrease. The introduction of doxycycline led to a further reduction in estradiol levels to 47ng/ml, which is approximately a 29.4% drop. Western blot analysis using a CT antibody revealed heightened AIPB expression in MDA-MD-231-AIPB cells when stress and doxycycline treatments were combined. Conclusions: Given the absence of aromatase in triple-negative breast cancer, our findings suggest that AIPB’s role in estradiol production is independent of aromatase, highlighting its significance in these cancer cells. The data supports the hypothesis that enhancing AIPB expression could potentially improve patient outcomes by reducing estradiol synthesis.

CCNE1 amplification as marker of poor prognosis and novel therapeutic target in advanced breast cancer.

1040 Background: Cyclin E1 (CCNE1) overexpression or gene amplification is linked to dismal outcomes in various tumors, including breast cancer (BC). Recent studies suggest that CCNE1 amplification is a potential target for new synthetic lethality-based treatments, including CDK2-selective and PKMYT1 inhibition. This study explores the clinical and genomic characteristics of CCNE1-amplified BCs. Methods: We analyzed genomic and clinical data from consecutive BCs that underwent clinical tumor-normal targeted panel sequencing (MSK-IMPACT) between April 2014 and December 2021. Allele-specific copy number, including CCNE1 amplification, and fraction genome altered (FGA) were calculated by FACETS. Mutual exclusivity and co-occurrence analyses were performed using CoMEt. Benjamini–Hochberg method for multiple testing correction (q) was applied. Real-world progression-free survival (rwPFS) was assessed by the Kaplan Meier method and Cox models, focusing on patients with available pre-treatment samples. Results: Out of 3,753 BCs, 125 (3.3%) had CCNE1 amplification. A higher occurrence of CCNE1 amplification was noted in post-treatment (n=2,368) compared to treatment-naïve tumors (n=1,385; 4% vs 2.4%, p=0.007). CCNE1 amplification was less common in hormone receptor (HR)+/HER2- BCs (2%) compared to HER2+ (7.6%) and triple-negative (7.2%) tumors (p&lt;0.001). BCs with CCNE1 amplification showed higher median FGA, indicating increased genomic instability. In primary BC, TP53 alterations were more frequent in CCNE1-amplified tumors (q&lt;0.001), while CDH1 alterations were mutually exclusive (q&lt;0.001) suggesting that lobular BCs rarely harbor CCNE1 amplification. Similar trends were seen in post-treatment samples. CCNE1 amplification detected at baseline was linked to shorter median rwPFS in HR+/HER2- metastatic BCs treated with CDK4/6 inhibitors plus endocrine therapy (8.8 vs 15.2 months in CCNE1-amplified [n=9] vs CCNE1-non amplified [n=402]; hazard ratio [HR] 2.82, 95% CI 1.38-5.75), and in HER2+ metastatic BCs treated with first-line THP regimen (7.3 vs 20.8 months in CCNE1-amplified [n=5] vs CCNE1-non amplified [n=106]; HR 3.1, 95% CI 1.24-7.87). In a CCNE1-amplified triple-negative cell model (HCC1569), treatment with the PKMYT1 inhibitor RP-6306 significantly reduced tumor growth. Conclusions: CCNE1 amplification in BCs is associated with greater genomic instability and characterizes a group of metastatic BCs with poor response to standard of care therapies. Novel therapies targeting CCNE1-amplified tumors are under evaluation in preclinical and clinical studies.

Molecular pathways of common breast cancer metastases and the distinguishing features of triple-negative breast cancer

Breast cancer is the most common type of female cancer in Turkey, and metastasis is the most important cause of death, as in other solid organ cancers. Triple-negative tumors constitute 15-20% of breast cancer patients. Within three years after the development of the primary tumor, the tumor spreads to other organs. Breast cancer tends to spread to distant organs, such as bone, liver, brain, lung, and adrenal gland, either through regional lymph nodes or vascular channels. This condition, defined as the tendency to metastasize to specific organs, is called organotropism. Triple-negative breast cancer is a heterogeneous breast cancer subtype showing organotropism for the brain and the lungs. Identifying the molecular changes that may cause tropism for various regions and organs in non-metastatic tumors at the time of diagnosis is vital to developing targeted therapies and achieving longer overall and disease-free survival. In this review, we aimed to summarize the pathogenesis of breast cancer metastasis, the molecular changes involved in the metastatic process, and organotropism, as well as to emphasize the distinguishing features of triple-negative breast cancer in terms of metastatic organotropism.