Common Type Of Breast Cancer Research Articles

MAP3K1 mutations confer tumor immune heterogeneity in hormone receptor-positive HER2-negative breast cancer.

Hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer, the most common type of breast cancer, is facing challenges such as endocrine therapy resistance and distant relapse. Immunotherapy has shown progress in treating triple-negative breast cancer, but immunological research on HR+/HER2- breast cancer is still in its early stages. Here, we performed a multi-omics analysis of a large cohort of HR+/HER2- breast cancer patients (n = 351) and revealed that HR+/HER2- breast cancer possessed a highly heterogeneous tumor immune microenvironment. Notably, the immunological heterogeneity of HR+/HER2- breast cancer was related to MAP3K1 mutation and we validated experimentally that MAP3K1 mutation could attenuate CD8+ T cell-mediated antitumor immunity. Mechanistically, MAP3K1 mutation suppressed MHC-I-mediated tumor antigen presentation through promoting the degradation of antigen peptide transporter 1/2 (TAP1/2) mRNAs, thereby driving tumor immune escape. In preclinical models, the postbiotics tyramine could reverse the MAP3K1 mutation-induced MHC-I reduction, thereby augmenting the efficacy of immunotherapy. Collectively, our study identified the vital biomarker driving the immunological heterogeneity of HR+/HER2- breast cancer and elucidated the underlying molecular mechanisms, which provided the promise of tyramine as a novel therapeutic strategy to enhance the efficacy of immunotherapy.

Exosomal Delivery of miR-155 Inhibitor can Suppress Migration, Invasion, and Angiogenesis Via PTEN and DUSP14 in Triple-negative Breast Cancer.

Triple-Negative Breast Cancer (TNBC) is the most common type of breast cancer (BC). In order to develop effective treatments for TNBC, it is vital to identify potential therapeutic targets. Angiogenesis stimulates tumor growth and metastasis in TNBC, and miR-155 plays a crucial role in this process. The exosome is a nano-sized vesicle that carries many cargoes, including miRNAs. The present study investigated the effect of exosomal delivery of miR-155 antagomir on tumor migration, invasion, and angiogenesis in TNBC. From MDA-MB-231 cells, exosomes were extracted, characterized, and loaded with miR-155 antagomir using electroporation. The expression of miR-155 and its target genes, including PTEN and DUSP14, was analyzed using RTqPCR. The wound-healing and transwell assays were used to measure cell migration and invasion. Furthermore, angiogenesis was evaluated by tube formation and chorioallantoic membrane (CAM) assays. The results indicated that exosomal delivery of miR-155 antagomir to HUVEC cells significantly suppressed miR-155 expression while upregulating PTEN and DUSP14. The tube formation properties of HUVEC cells were also significantly reduced following treatment with exosomes containing miR-155 antagomirs, and these results were confirmed using CAM assay. The migration and invasion of MDA-MB-231 cells were significantly reduced after treatment with miR-155 antagomir-loaded exosomes. It was found that miR-155 antagomir delivery using exosomes can inhibit migration, invasion, and angiogenesis viaPTEN and DUSP14 in TNBC.

Ten-year outcomes of targeted axillary surgery after neoadjuvant chemotherapy in breast cancer.

600 Background: When pathological complete response (pCR) is achieved in node-positive breast cancer after neoadjuvant chemotherapy (NAC), identifying traces of the previous lesion becomes challenging which makes accurate surgery difficult. We conducted targeted axillary surgery (TAS) in node-positive breast cancer after NAC, which involves accurately targeting the lymph nodes where metastasis occurred and performing surgery using a less extensive method. The 10-year outcomes were compared with those of patients who underwent conventional axillary lymph node dissection (ALND). Methods: We conducted a retrospective analysis of 235 patients with cT1-3N1-2 breast cancer who received NAC from 2012 to 2017. In this cohort, 78 patients underwent TAS only, and 157 underwent conventional ALND, including 31 patients who initially received TAS followed by additional ALND. Oncologic results, including locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), and overall survival (OS), were assessed over a 10-year follow-up period. Survival outcomes for all patients and each subtype were analyzed using Kaplan-Meier survival methods. Results: The TAS group had significantly more postmenopausal patients (p=0.022), and the most common type of breast cancer was invasive ductal carcinoma [TAS: 75 (96.2%); ALND: 157 (100.0%)]. There was no statistical difference in the T stage and the number of lymph nodes suspected of metastasis at diagnosis (p=0.062, 0.985). Mastectomy was performed in 60.3% of patients in the TAS group and 93.0% in the ALND group (p<0.001), and 68 (87.2%) of the TAS group and 41 (26.1%) of the ALND group received additional axillary radiotherapy (p=0.019). There was no significant difference in oncologic outcomes between the TAS and ALND groups in all patients (LRFS, p=0.673; DMFS, p=0.729; OS, p=0.396) and based on subtypes, including hormone receptor (HR)-positive, HER2-positive, and triple-negative breast cancer (TNBC). In the HR-positive breast cancer group, the TAS and ALND groups showed very similar trends (LRFS, p=0.954; DMFS, p=0.993; OS, p=0.617). In HER2-positive breast cancer, although not statistically significant, the survival outcomes were better in the TAS group than in the ALND group (LRFS, p=0.967; DMFS, p=0.999; OS, p=0.423). However, the OS in the TAS group for TNBC was lower than that in the ALND group, though not significantly (LRFS, p=0.411; DMFS, p=0.697; OS, p=0.210). Conclusions: This study demonstrates that TAS is comparable to ALND in terms of 10-year oncological outcomes across different types of node-positive breast cancer, suggesting its potential as a viable alternative. However, further research focusing on patient quality of life and postoperative complications is essential to establish TAS as a superior surgical option to ALND.

Abstract PO5-21-05: An Endocrine Resistant-Related Gene Signature Revealing the Tumor Microenvironment to Predict the Prognosis of Hormone Receptor-Positive Breast Cancer Patients

Abstract Key words: breast cancer; hormone receptor-positive; predictive model; prognosis; endocrine therapy; drug resistance Hormone receptor positive (HR+) breast cancer is the most common type of breast cancer, accounting for approximately 70% of all breast cancer, in whom endocrine therapy plays a vital role. However, the limited effectiveness of endocrine therapy due to intricate mechanisms of drug resistance poses a significant challenge in treating certain patients. Therefore, it is imperative to identify novel indicators of endocrine resistance and develop new models for predicting recurrence-free survival (RFS) in patients with HR+ breast cancer. In this study, we successfully established an endocrine resistance-related risk model based on multicenter RNA sequencing data. This model could represent tumor microenvironment characteristics and provide valuable insights into predicting the prognosis of HR+ breast cancer patients. A seven gene risk model reflecting endocrine therapy resistance in 208 early HR+ breast cancer patients from two centers was constructed by LASSO analysis and multivariate cox regression. Based on the median value of risk score, patients were divided into high-risk group and low-risk group. Compared with the low-risk group, the high-risk group exhibited a significantly worse prognosis, which showed consistent across two external validation cohorts (TCGA-BRCA and METABRIC cohort). Time dependent ROC curve showed excellent capacity of gene model in predicting 1,3 and 5-year RFS. The IC50 analysis revealed that patients in low-risk group exhibited greater sensitivity to endocrine drugs, such as tamoxifen, fulvestrant and palbociclib, which strongly suggested that the identified gene signature can effectively differentiate between endocrine-resistant and -sensitive status. Gene-set enrichment analysis revealed regulation of cell killing, positive regulation of inflammatory response and T cell mediated cytotoxicity were enriched in low risk group, suggesting immune activation and a higher immune infiltration status. Conversely, the high-risk group demonstrated associations with collagen metabolic process, extracellular matrix structural constituent and collagen fibril organization, which were the indicative of the location and function of cancer-associated fibroblasts (CAFs). As expected, ssGSEA results revealed elevated expression levels of immune cells (e.g., natural killer cells, tumor-infiltrating lymphocytes, CD8+ T cells) and immune functions (e.g., T cell co-stimulation, inflammation-promoting, cytolytic activity) in the low-risk group. However, three diverse acknowledged methods (TIDE, EPIC and MCP-counter) consistently identified CAFs as predominantly content in the high-risk groups. Furthermore, considering that CD8+ T cell is the primary cell type responsible for exerting cytotoxic effects, we observed a negative correlation between CD8+ T cells and CAFs. This suggests that CAFs may inhibit the infiltration of CD8+ T cells, thereby weakening their cytotoxic capabilities, leading to a shorter RFS in high-risk patient groups. In conclusion, a novel gene signature constructed with 7 endocrine resistance response-related genes can be used for prognostic prediction and reflecting the tumor microenvironment status in HR+ early breast cancer. The low-risk group exhibited enhanced anti-tumor immunity, resulting in a favorable prognosis. In contrast, the high-risk group displayed pronounced infiltration of CAFs, indicating their potential to impede immune cell infiltration and impact the efficacy of endocrine drugs through the formation of physical barriers and recruitment of immunosuppressive factors. Consequently, patients in the high-risk group experienced a worse prognosis. Therefore, inhibiting these genes may be a therapeutic option for overcoming endocrine therapy resistance in HR+ breast cancer patients. Citation Format: Xiyu Kang, Jiaxiang Liu, Xin Wang. An Endocrine Resistant-Related Gene Signature Revealing the Tumor Microenvironment to Predict the Prognosis of Hormone Receptor-Positive Breast Cancer Patients [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-21-05.

RETRACTED ARTICLE: Tumor microenvironment and immune system preservation in early-stage breast cancer: routes for early recurrence after mastectomy and treatment for lobular and ductal forms of disease

BackgroundIntra-ductal cancer (IDC) is the most common type of breast cancer, with intra-lobular cancer (ILC) coming in second. Surgery is the primary treatment for early stage breast cancer. There are now irrefutable data demonstrating that the immune context of breast tumors can influence growth and metastasis. Adjuvant chemotherapy may be administered in patients who are at a high risk of recurrence. Our goal was to identify the processes underlying both types of early local recurrences.MethodsThis was a case-control observational study. Within 2 years of receiving adjuvant taxan and anthracycline-based chemotherapy, as well as modified radical mastectomy (MRM), early stage IDC and ILC recurred. Vimentin, α-smooth muscle actin (SMA), platelet-derived growth factor (PDGF), matrix metalloproteinase (MMP1), and clustered differentiation (CD95) were investigated.ResultsOf the samples in the ductal type group, 25 showed local recurrence, and 25 did not. Six individuals in the lobular-type group did not experience recurrence, whereas seven did. Vimentin (p = 0.000 and 0.021), PDGF (p = 0.000 and 0.002), and CD95 (p = 0.000 and 0.045) expressions were significantly different in ductal and lobular carcinoma types, respectively. Measurement of ductal type was the sole significant difference found in MMP1 (p = 0.000) and α-SMA (p = 0.000). α-SMA and CD95 were two variables that helped the recurrence mechanism in the ductal type according to the pathway analysis. In contrast, the CD95 route is a recurrent mechanism for the lobular form.ConclusionsWhile the immune system plays a larger role in ILC, the tumor microenvironment and immune system both influence the recurrence of IDC. According to this study, improving the immune system may be a viable cancer treatment option.

Paediatric and Adolescent Breast Cancer: A Narrative Review.

Breast canceris the most prevalent form of cancer worldwide. Every year, it affects a significant number of women in the UK and is considered one of the leading causes of cancer-related deaths globally. While breast cancer is primarily linked to adult women, its occurrence in children and adolescents is exceedingly rare. This study conducted a narrative review spanning from 1999 to 2023, examining 32 case reports to investigate the characteristics of breast cancer in the paediatric age group. These reports focused on patients under 18 years old who were diagnosed with primary glandular breast cancer, excluding cases originating from other tissues like angiosarcoma, leukaemia, and metastatic cancer. The data analysis encompassed various parameters, including gender, age, histology, receptor status, lymph node involvement, treatment methods, and genetic characteristics. From the published case reports, it was concluded that the most common type of breast cancer affecting children and adolescents is secretory breast carcinomaand predominantly occurs in females. It is typically hormone receptors negative, and the preferred treatment approach involves mastectomy as breast conservation surgery to preserve the developing breast tissue is a real challengedue to limited breast tissue volume in this age group.

Identification of prognostic biomarkers of invasive ductal carcinoma by an integrated bioinformatics approach

Background: Invasive ductal carcinoma (IDC) is the most common type of breast cancer (BC) worldwide. Nowadays, due to its heterogeneity and high capacity for metastasis, it is necessary to discover novel diagnostic and prognostic biomarkers. Therefore, this study aimed to identify novel candidate prognostic genes for IDC using an integrated bioinformatics approach. Methods: Three expression profile data sets were obtained from GEO (GSE29044, GSE3229, and GSE21422), from which differentially expressed genes (DEGs) were extracted for comparative transcriptome analysis of experimental groups (IDC versus control). Next, STRING was utilized to construct a protein interaction network with the shared DEGs, and MCODE and cytoHubba were used to identify the hub genes, which were then characterized using functional enrichment analysis in DAVID and KEGG. Finally, using the Kaplan-Meier tracer database, we determined the correlation between the expression of hub genes and overall survival in BC. Results: We identified seven hub genes (Kinesin-like protein KIF23 [KIF23], abnormal spindle-like microcephaly [ASPM]-associated protein [ASPMAP], Aurora kinase A [AURKA], Rac GTPase-activating protein 1 [RACGAP1], centromere protein F [CENPF], hyaluronan-mediated motility receptor [HMMR], and protein regulator of cytokinesis 1 [PRC1]), which were abundant in microtubule binding and tubulin binding, pathways linked to fundamental cellular structures including the mitotic spindle, spindle, microtubule, and spindle pole. The role of these genes in the pathophysiology of IDC is not yet well characterized; however, they have been associated with other common types of BC, modulating pathways such as Wnt/β-catenin, the epithelial-to-mesenchymal transition (EMT) process, chromosomal instability (CIN), PI3K/AKT/mTOR, and BRCA1 and BRCA2, playing an important role in its progression and being associated with a poor prognosis, thus representing a way to improve our understanding of the process of tumorigenesis and the underlying molecular events of IDC. Conclusions: Genes identified may lead to the discovery of new prognostic targets for IDC.

Randomized phase III trial evaluating motivational interviewing and text interventions to optimize adherence to breast cancer endocrine therapy (Alliance A191901): the GETSET protocol

BackgroundHormone receptor-positive (HR +) breast cancer is the most common type of breast cancer in the USA but has excellent long-term outcomes in recent decades, in part due to effective oral endocrine therapy (ET). ET medications are typically prescribed for 5 to 10 years, depending on the risk of recurrence, and must be taken daily. One limiting factor to ET efficacy is nonadherence, with high-risk groups for nonadherence including younger women and Black women.MethodsThe Alliance for Clinical Trials in Oncology (Alliance) trial A191901 is an ongoing, four-arm (text message reminder (TMR), motivational interviewing (MI), TMR plus MI, or enhanced usual care) randomized clinical trial that tests the efficacy and effect of two interventions (TMR and/or MI) on improved ET adherence, patient-reported outcomes (PROs), and resource use requirements among HR + breast cancer survivors. Participants are randomized in a 1:1:1:1 ratio to the four arms. With an assumed loss to follow-up of approximately 11%, we plan to recruit 1180 participants. Randomization is stratified based on age and race to ensure balance between the arms, and we oversample younger and Black women, with each group representing 30% of the study population. Participants randomized to an intervention will actively participate in the intervention for 9 months, and all participants will be followed for adherence data and PRO endpoints, through the use of the Pillsy cap medication event monitoring system and Alliance ePRO survey app (i.e., Patient Cloud). The primary analysis will compare Pillsy-measured ET adherence among study arms at 12 months.DiscussionThis multisite study will not only define strategies to improve adherence to breast cancer oral therapies, but it will also potentially support strategies in large cooperative research groups that can increase delivery and tolerability of ET, involve diverse patient populations in clinical research, and engage patients effectively in interventional studies, using remote and cost-effective delivery methods.Trial registrationClinicaltrials.gov NCT04379570. Registered on 7 May 2020.

Immune system and tumor microenvironment in early-stage breast cancer: different mechanisms for early recurrence after mastectomy and chemotherapy on ductal and lobular types.

Background: The most common type of breast cancer is the ductal type (IDC), followed by lobular type (ILC). Surgery is the main therapy for early-stage breast cancer. Adjuvant chemotherapy might be given to those at high risk of recurrence. Recurrence is still possible after mastectomy and chemotherapy and most often occurs in the first two years. We aimed to determine the mechanisms in early local recurrence in both types. Methods: We used an observational method with a cross-sectional study design. The samples were patients with early-stage IDC and ILC, who underwent modified radical mastectomy (MRM) and got adjuvant chemotherapy with taxan and anthracycline base, and experienced recurrence in the first two years after surgery. The materials in this study were paraffin blocks from surgical specimens; we examined vimentin, α-SMA and MMP1, PDGF and CD95 by immunohistochemistry (IHC). Data analysis was done using OpenEpi 3.0.1 and EZR. We used pathway analysis with linear regression. Results: There were 25 samples with local recurrence and 25 samples without recurrence in the ductal type group. The lobular type group consisted of six subjects without recurrence and seven with recurrence. There were significant differences in the expression of vimentin (p=0.000 and 0.021, respectively), PDGF (p=0.000 and 0.002) and CD95 (p=0.000 and 0.045) in ductal and lobular cancer types, respectively. MMP1 (p=0.000) and α-SMA (p=0.000) only showed a significant difference in the ductal type. The pathway analysis showed that in the ductal type, the mechanism of recurrence was enabled by two factors: α-SMA and CD95. Meanwhile, for the lobular type, the recurrence mechanism was through the CD95 pathway. Conclusions: Local recurrence in early-stage IDC and ILC had different mechanisms. These findings are expected to make cancer treatment in both types more focused and efficient.

Immune system and tumor microenvironment in early-stage breast cancer: different mechanisms for early recurrence after mastectomy and chemotherapy on ductal and lobular types

Background: The most common type of breast cancer is the ductal type (IDC), followed by lobular type (ILC). Surgery is the main therapy for early-stage breast cancer. Adjuvant chemotherapy might be given to those at high risk of recurrence. Recurrence is still possible after mastectomy and chemotherapy and most often occurs in the first two years. We aimed to determine the mechanisms in early local recurrence in both types. Methods: We used an observational method with a cross-sectional study design. The samples were patients with early-stage IDC and ILC, who underwent modified radical mastectomy (MRM) and got adjuvant chemotherapy with taxan and anthracycline base, and experienced recurrence in the first two years after surgery. The materials in this study were paraffin blocks from surgical specimens; we examined vimentin, α-SMA and MMP1, PDGF and CD95 by immunohistochemistry (IHC). Data analysis was done using OpenEpi 3.0.1 and EZR. We used pathway analysis with linear regression. Results: There were 25 samples with local recurrence and 25 samples without recurrence in the ductal type group. The lobular type group consisted of six subjects without recurrence and seven with recurrence. There were significant differences in the expression of vimentin (p = 0.000 and 0.021, respectively), PDGF (p = 0.000 and 0.002) and CD95 (p = 0.000 and 0.045) in ductal and lobular cancer types, respectively. MMP1 (p = 0.000) and α-SMA (p = 0.000) only showed a significant difference in the ductal type. The pathway analysis showed that in the ductal type, the mechanism of recurrence was enabled by two factors: α-SMA and CD95. Meanwhile, for the lobular type, the recurrence mechanism was through the CD95 pathway. Conclusions: Local recurrence in early-stage IDC and ILC had different mechanisms. These findings are expected to make cancer treatment in both types more focused and efficient.

Area Deprivation Index in patients with invasive lobular carcinoma of the breast: associations with tumor characteristics and outcomes.

While investigators have shown associations between socioeconomic status (SES) and outcomes in breast cancer, there is a paucity of such data for invasive lobular carcinoma (ILC), the second most common type of breast cancer. Herein we evaluated the relationship between SES with tumor features and outcomes in stage I-III patients with ILC. We analyzed a prospectively maintained institutional ILC database and utilized the Area Deprivation Index (ADI) to determine neighborhood adversity, an indicator of SES. We used Cox proportional hazards models in Stata 17.0 to evaluate relationships between ADI quintile (Q), race, body mass index (BMI), clinicopathologic features, treatment type, and event-free survival (EFS). Of 804 patients with ILC, 21.4% lived in neighborhoods classified as ADI Q1 (least resource-deprived) and 19.7% in Q5 (most resource-deprived). Higher deprivation was significantly associated with larger tumor size (3.6 cm in Q5 versus 3.1 cm in Q1), increased presence of lymphovascular invasion (8.9% in Q5 versus 6.7% in Q1), and decreased use of adjuvant endocrine therapy (67.1% in Q5 versus 73.6% in Q1). On multivariable analysis, tumor size, receptor subtypes, and omission of adjuvant endocrine therapy were associated with reduced EFS. These data show that patients with ILC and higher ADI experience more aggressive tumors and differences in treatment. More data evaluating the complex relationships between these factors is needed to optimize outcomes for patients with ILC, regardless of SES. ADI is associated with differences in patients with ILC.

Histological and electron microscopic features of the extracellular matrix of invasive breast ductal carcinoma of no special type. Report of 5 cases and literature review

ABSTRACT Invasive ductal carcinoma of no special type is the most common type of breast cancer. In light of the above, many authors have reported the histological and electron microscopic characteristics of these tumors. On the other hand, a limited number of works exist where the authors have concentrated on investigating the extracellular matrix. This article presents data received as the results of light and electron microscopic examination of the extracellular matrix, angiogenesis, and cellular microenvironment of invasive breast ductal carcinoma of no special type. The authors have shown that the processes of stroma formation in the IDC NOS type are associated with the presence of fibroblasts, macrophages, dendritic cells, lymphocytes, and other cells. It was also shown the detailed interaction of the above cells with each other, as well as with vessels and fibrillar proteins such as collagen and elastin. The microcirculatory component is characterized by histophysiological heterogeneity, which manifests as the activation of angiogenesis, relative vascular differentiation, and regression of individual microcirculation components.

Epstein-Barr Viral Infection and the Risk for Breast Cancer: A Systematic Review.

Background: The prevalence of breast cancer has increased and has currently become one of the most common cancers. Although the majority of the world's population is infected with Epstein Barr Virus (EBV) during their lives, the severity of symptoms varies and not everyone infected with EBV is diagnosed with cancer. EBV might increase the risk for breast cancer either by activating the HER2/HER3 signaling cascades or by creating a state of prolonged immune stimulation. Materials and Methods: A systematic search of several electronic databases including PubMed, ScienceDirect, Cochrane, EBSCOhost, JSTOR, and Scopus, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted. The primary outcome of this review was to assess the prevalence of people with breast cancer that had a prior EBV infection. Results: For this review, 24 case-control studies were accepted. Our analyses included 1.989 breast cancer cases versus 1.034 control cases. EBV was found to be present in 27.9% of breast cancer cases versus 8.02% found in the normal breast tissue of controls. All affected people were women with a mean age was 48.19 years. The most common type of breast cancer found in EBV-infected tissues was invasive breast cancer. Cases were reported sporadically in a wide geographical distribution, and the prevalence varied from 4.6% - 64.1%. Conclusions: A previous EBV infection might be associated with a higher risk for breast malignancy. The most common type is invasive cancer. It mainly affects women and geographical variances are observed. More studies are necessary to elucidate the role of EBV in the mechanisms of breast cancer. Also, it is crucial to improve the prevention and treatment strategies.

Abstract 4354: An exosome-based ESR1 monitoring RT-qPCR technology that rapidly and accurately detects circulating tumor acquired resistance variants at ≤0.1% frequency in liquid biopsy samples

Abstract Introduction: Hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer is the most common type of breast cancer. Patients with HR+/HER2- metastatic breast cancer (mBC) often become resistant to aromatase inhibitors commonly used in endocrine therapy (ET). Estrogen receptor (ESR1) ligand binding domain mutations are frequently detected in HR+ mBC and have been reported to be associated with ET resistance, noting up to 60% patients with mBC will develop resistance to treatment via acquired resistance in ESR1. Recent studies have shown that monitoring of ESR1 mutations in plasma may serve as a predictive biomarker of acquired resistance to ET, showcasing a strong need for sensitive nucleic acid-based assays. We describe a comprehensive methodology for targeted clinical RT-qPCR monitoring of ESR1 mutations in plasma that utilizes both exosomal nucleic acids and cfDNA to report multiple mutations, provide a streamlined workflow, and accommodate a range of inputs from clinically relevant samples. Methods: Exosomal nucleic acids (exosomal DNA and RNA) and circulating cell-free DNA (cfDNA) were co-isolated using the ExoLution Plus Isolation Kit (Exosome Diagnostics). RT-qPCR-based target enrichment was performed using modified QuantideX reagents (Asuragen) and mutations were confirmed on the QuantStudio qPCR Platform (ThermoFisher). Bioinformatic analyses were conducted using custom software. Results: We developed novel technologies and tested greater than samples across key ET resistance mutations, utilizing contrived samples as needed due to availability. Preliminary studies demonstrated that ESR1 exosomal RNA + cfDNA ranged from approximately 9,500 copies to 64,000 copies in a set of 2mL female presumed normal plasma samples; these results suggest that even 2mL plasma could provide sufficient exosomal RNA/DNA + cfDNA for mutation detection at variant frequencies less than or equal to 0.01%. The ESR1 RT-qPCR showed greater than 90% analytical sensitivity (at less than or equal to 1% mutant allele frequency) and greater than90% analytical specificity. Further, the technology detected less than 10 mutant copies for most tested mutants, showing an LOD of at least 0.1% (5 mutant copies in a background of 5,000 WT copies). Conclusion: A fast, efficient, and sensitive ESR1 RT-qPCR panel approach was developed and evaluated, demonstrating the reliable and specific detection of rare variants in liquid biopsy specimens. Importantly, this prototype technology has potential to address several challenges associated with mutation monitoring in liquid biopsies by expanding detection of mutant analytes (exosomal RNA and DNA), improving analytical sensitivity (novel reagents and software), and increasing accessibility (qPCR instrument install base). Citation Format: Sarah Statt, Julie Thibert, Kurt Franzen, Aquiles Sanchez, Liangjing Chen, Megan Yociss, Elliot Hallmark, Melissa Church, Stela Filipovic-Sadic, Gary Latham, Johan Skog. An exosome-based ESR1 monitoring RT-qPCR technology that rapidly and accurately detects circulating tumor acquired resistance variants at ≤0.1% frequency in liquid biopsy samples. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4354.

53 The development of a multi-institutional prospective registry for patients with metastatic invasive lobular carcinoma: identifying new markers of disease progression

OBJECTIVES/GOALS: We are launching a multi-center prospective registry for patients with metastatic invasive lobular carcinoma (ILC), the second most common type of breast cancer, to better understand patterns of progression, imaging features of metastatic sites, and if serial cell free DNA measurements can serve as a surrogate marker of disease progression. METHODS/STUDY POPULATION: Patients with biopsy proven metastatic ILC of any receptor subtype will be included in the registry. We will exclude patients with ductal histology only or those with multiple primary malignancies. Patients will be enrolled at four large academic medical centers across the country. Cell free DNA measurements using a tumor informed assay will be obtained every 3 months concurrent with regular clinical imaging. Disease status will be determined by the patient’s medical oncologist by taking into account imaging, tumor markers, symptoms, and cell free DNA measurement. At each time point, patients will be surveyed on their quality of life and their medical oncologists will be asked to rate the clinical utility of the cell free DNA value. Patients will be followed indefinitely. RESULTS/ANTICIPATED RESULTS: We will explore whether the use of serial cell free DNA or a combination of blood-based biomarkers and clinical endpoints can reliably identify treatment response and disease progression in patients with metastatic ILC. Many patients with metastatic ILC have unmeasurable disease on imaging and are thereby excluded from clinical trials. The end goal of this registry is to determine if blood-based biomarkers can be used as a proxy for measurable disease in ILC patients and therefore increase clinical trial enrollment for this subgroup of patients. DISCUSSION/SIGNIFICANCE: The creation of this prospective registry will open the door for future studies of blood-based markers that reflect disease stability and progression, which is an unmet need specifically in ILC. Identification of such markers could lead to a novel treatment response endpoint, changing the way patients are enrolled in trials and managed clinically.

Invasive Lobular Carcinoma: A Review of Imaging Modalities with Special Focus on Pathology Concordance.

Invasive lobular cancer (ILC) is the second most common type of breast cancer. It is characterized by a unique growth pattern making it difficult to detect on conventional breast imaging. ILC can be multicentric, multifocal, and bilateral, with a high likelihood of incomplete excision after breast-conserving surgery. We reviewed the conventional as well as newly emerging imaging modalities for detecting and determining the extent of ILC- and compared the main advantages of MRI vs. contrast-enhanced mammogram (CEM). Our review of the literature finds that MRI and CEM clearly surpass conventional breast imaging in terms of sensitivity, specificity, ipsilateral and contralateral cancer detection, concordance, and estimation of tumor size for ILC. Both MRI and CEM have each been shown to enhance surgical outcomes in patients with newly diagnosed ILC that had one of these imaging modalities added to their preoperative workup.

Abstract P6-08-09: Self-identified race and Area Deprivation Index in patients with invasive lobular carcinoma of the breast: associations with tumor characteristics and event free survival

Abstract Objectives: Investigators have shown a relationship between race/ethnicity and survival in invasive lobular carcinoma (ILC), the second most common type of breast cancer. While non-white patients with ILC were shown to have worse outcomes, there are no data evaluating the impact of socioeconomic factors. Herein we evaluated the relationship between self-reported race and socioeconomic factors with tumor features and outcomes in early-stage patients with ILC. Methods: We used chi-squared tests, t-tests, the Kruskal-Wallis test, multivariate Cox proportional hazards models, and tests for trend in Stata 16.1 to evaluate race, area deprivation index (ADI), and event-free survival (EFS) in a single institution cohort of patients with stage I-III ILC. Race was self-reported and categorized as black, white, or other. ADI was ascertained from a publicly available database using measures of income, education level, employment, and housing quality to provide information about neighborhood adversity. ADI was evaluated in quintiles, with quintile 1 signifying the least resource deprived neighborhoods, and quintile 5 signifying the most resource deprived. Tumor receptor subtype was defined by estrogen receptor (ER), progesterone receptor (PR), and HER2 status. Body mass index (BMI) of 18.5-24.9 kg/m2 was categorized as normal, 25-29.9 kg/m2 as overweight, and ≥ 30 kg/m2 as obese. Results: Of 823 patients in our institutional database, self-reported race/ethnicity data were available for 808, with 28 (3.5%) identifying as black, 638 (79.0%) as white, and 142 (17.6%) as other. ADI data were available for 816 patients, with 174 (21.3%) in quintile 1, 210 (25.7%) in quintile 2, 110 (13.5%) in quintile 3, 163 (20.0%) in quintile 4, and 159 (19.5%) in quintile 5. Tumor receptor subtype differed by ADI, with patients in the highest ADI category (most resource-deprived) being most likely to have ER positive, PR positive, and HER2 negative tumors (81.8% in ADI category 5 versus 69.0% in ADI category 1, p=0.001). Those in higher ADI categories were also more likely to have lymphovascular invasion (9.2% in ADI category 5 versus 4.3% in ADI category 1, p=0.008), and were less likely to present with stage I disease (55.5% in ADI category 5 versus 67.9% in ADI category 1, p=0.002). BMI was not associated with tumor characteristics, but was significantly associated with ADI, with a significant trend towards higher BMI in areas of higher ADI (p< 0.001). Among patients who self-identified as black, age at diagnosis was significantly higher compared to those identifying as white or other (mean age 65.8, 59.9, and 58.0 years respectively, p=0.0074). There were no differences in tumor receptor subtype, grade, presence of LVI, or stage by self-identified race. Black-identifying patients were significantly less likely to have the lowest ADI category (0% versus 22.6% and 20.4% in white and other categories respectively, p=0.016), and were significantly more likely to have elevated BMI (79.2% overweight/obese versus 47% of white and 41.5% of other patients, p=0.003). On univariate analysis, self-identified black race, elevated ADI, and overweight/obesity were each associated with significantly worse EFS. However, in a multivariate model containing all three predictors, only overweight/obesity remained significantly associated with worse EFS (hazard ratio 1.6, 95% confidence interval 1.1-2.3, p=0.022). Conclusions: Although prior investigators identified a relationship between non-white race and worse outcomes in patients with ILC, our data show complex relationships between many factors that impact breast cancer outcomes. The relationship between race and EFS was mitigated by ADI and obesity, suggesting that race is not an independent predictor of outcome in patients with ILC. Citation Format: Mandeep Kaur, Anne Patterson, Julissa Molina-Vega, Harriet T. Rothschild, Elle Clelland, Mary Kathryn Abel, Laura J. Esserman, Olufunmilayo I. Olopade, Rita Mukhtar. Self-identified race and Area Deprivation Index in patients with invasive lobular carcinoma of the breast: associations with tumor characteristics and event free survival [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 P6-08-09.

Abstract P2-03-16: Quantifying estrogen and progesterone receptor status in early-stage invasive lobular carcinoma of the breast: associated factors and outcomes in an institutional series

Abstract Background: Recent guidelines regarding estrogen (ER) and progesterone (PR) receptor testing from the American Society of Clinical Oncology and College of American Pathologists defined a new reporting category of ER-low positive breast cancer for tumors with 1-10% ER expression by immunohistochemistry (IHC). The clinical implications of ER-low positivity are incompletely understood, especially in invasive lobular carcinoma (ILC), the second most common type of breast cancer. Given the rarity of low-ER positivity in ILC, we evaluated tumor features and outcomes associated with a spectrum of ER/PR positivity in a monoinstitutional ILC cohort. Methods: We analyzed cases of stage I-III ILC with available IHC reports. Based on prior published categories in ILC, we classified ER as low, medium, or high as defined by ER staining of 10–69%, 70–89%, and ≥90% respectively. PR negative, low, and high tumors were defined by 0%, < 20%, or ≥20% staining respectively. We used chi-squared tests, t-tests, and Cox proportional hazards models in Stata 16.1 to evaluate associations between ER/PR categories including clinicopathologic variables and event-free survival (EFS). Results: Of 744 cases, 24 (3.2%) were ER negative and 10 (1.3%) were ER-low positive as defined by 1-10% positive staining. 713 remaining cases had ER positivity ≥ 10% and comprised the cohort categories of ER low, medium, and high for this study (11.2%, 15.0%, and 73.8% respectively). In 751 cases with PR data, 122 (16.2%) were PR negative, 145 (19.4%) were PR low and 483 (64.3%) were PR high. ER high status was significantly associated with older age (mean 56.7, 56.7, and 60.6 years in ER low, medium, and high respectively, p=0.0005). ER low was associated with PR negative and low status (42.3% were PR neg/low and ER low, versus 37.4% with ER medium and 29.9% in ER high, p=0.045), and more likely to have overexpression of HER2 (9.7%, 9.0%, and 2.9% ER low, medium, high, respectively, p=0.002). ER low tumors were more likely to be grade 1 than ER medium or high (41.8%, 29.8% and 24.5% respectively, p=0.025), and have positive surgical margins (39.4%, 35.9% and 23.9% respectively, p=0.002). ER status was not associated with Ki67, stage, body mass index (BMI), lymphovascular invasion, lobular carcinoma in situ (LCIS), pleomorphic histology, local therapy, or chemotherapy use. In contrast, PR high was significantly associated with younger age (57.6 versus 63.5 years in PR low, p< 0.0001). PR low was associated with HER2 overexpression (8.6% versus 3.2% in PR high, p=0.002). PR low cases were more likely to present at higher stages (15.8% stage III versus 10.1% stage III in PR high, p=0.032), to be pleomorphic (16.8% versus 8.2%, p< 0.001), and to receive chemotherapy (30.8% versus 23.1%, p=0.022) but were less likely to have associated LCIS (64.0 versus 74.2%, p=0.004). PR status was not associated with Ki67, BMI, lymphovascular invasion, local therapy, or surgical margins. In a Cox proportional hazards model adjusting for age, stage, grade, pleomorphic histology, and chemotherapy use, ER category was not associated with EFS but both PR negative and PR low status each had significantly worse EFS compared to PR ≥20% (HR 3.5, 95% CI 1.8-6.7, p< 0.001 for PR negative, and HR 2.0, 95% CI 1.1-3.5, p=0.015 for PR low). The estimated cumulative 5-year EFS for patients with ER low, medium, and high tumors was 87.1%, 93.4%, and 90.1% respectively. The estimated cumulative 5-year EFS for patients with PR negative, low, and high tumors was 78.9%, 90.2%, and 92.7% respectively. Conclusions: Using ILC-specific categories for ER expression, we found associations between ER category and clinicopathologic variables but not with EFS. In contrast, PR negative and low status was associated with worse EFS. These findings highlight the importance of exploring the spectrum of ER/PR activity within ILC, a classically strongly hormone receptor-positive tumor type, using more quantitative methods. Citation Format: Elle Clelland, Harriet T. Rothschild, Anne Patterson, Julissa Molina-Vega, Mandeep Kaur, Mary Kathryn Abel, W. Fraser Symmans, Jo Chien, Christopher J. Schwartz, Rita Mukhtar. Quantifying estrogen and progesterone receptor status in early-stage invasive lobular carcinoma of the breast: associated factors and outcomes in an institutional series [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 P2-03-16.

Heterogeneity in hormone-dependent breast cancer and therapy: Steroid hormones, HER2, melanoma antigens, and cannabinoid receptors

Breast cancer is the most frequently diagnosed cancer and the leading cause of death by cancer among women worldwide. The prognosis of the disease and patients’ response to different types of therapies varies in different subgroups of this heterogeneous disease. The subgroups are based on histological and molecular characteristics of the tumor, especially the expression of estrogen (ER) and progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). Hormone-dependent breast cancer, determined predominantly by the presence of ER, is the most common type of breast cancer. Patients with hormone-dependent breast cancer have an available targeted therapy, however, tumor cells can develop resistance to the therapy, which is a major obstacle limiting the success of treatment and enabling relapse to metastatic disease. The complicated crosstalk of both tumor-intrinsic and exogenous factors may contribute to endocrine resistance, although the underlying molecular details are still enigmatic. For example, the expression of the melanoma antigen genes (MAGE) correlates with a worse clinical prognosis and therapy resistance in many types of cancers, including breast cancer. Recent studies suggested that cancers co-opt MAGEs’ physiological functions to promote therapy resistance and potentially metastasis development. The response to the therapy can be also affected by the concurrent use of alternative therapy, e.g., cannabinoid use is popular among breast cancer patients. Cannabinoids interact with endogenous estrogen function, however, how they interfere with breast cancer therapy is still poorly understood. In this review, we summarize the role of ER, PR, and HER2 in hormone-dependent breast cancer; provide current knowledge of MAGEs and cannabinoid receptors in breast cancer; ultimately discuss the potential interlacement of their signaling paths which may underlay diverse responses to therapies in breast cancer patients simultaneously using cannabinoids. These interactions are poorly understood but critical for the advancement of conventional and complementary treatment options for patients, particularly the ones with metastatic disease.

Artificial intelligence enhanced thermal breast imaging in the diagnosis of invasive breast cancer: a study of 2 case reports

Background: Invasive ductal carcinoma (IDC) of the breast is the most common type of breast cancer in women. Imaging by mammography and/or ultrasonography and histo-pathological examination are collectively used to confirm a diagnosis of IDC. However, the standard imaging modalities are resource intensive and hence, have limited feasibility in resource-limited countries. Thermalytix, an affordable, radiation-free test is a novel Artificial Intelligence (AI)-powered breast cancer detection tool that has shown effectiveness in detecting breast cancer in both symptomatic and asymptomatic women. Case Presentation: We describe two cases of symptomatic women who, on Thermalytix, were identified with a lesion suspicious of malignancy and confirmed as IDC on further evaluation by standard of care imaging and tissue diagnosis. Conclusion: Thermalytix, a new AI-based computer diagnostic solution (Computer diagnostic solution), has the potential to identify breast malignancies such as IDC.