Negative Breast Cancer Research Articles

Impact of race and age on intrinsic subtype distribution and treatment decisions in metastatic breast cancer: Preliminary analysis of HARMONY (LCCC1829).

1055 Background: Gene expression profiling (GEP) is used to classify breast cancer (BC) into four intrinsic subtypes: Luminal A (LumA), Luminal B (LumB), HER2-Enriched, and Basal-like. Non-LumA subtypes are associated with poorer outcomes. Studies in early BC show that hormone receptor-positive (HR+)/HER2-negative (HER2-) tumors have a higher frequency of non-LumA subtypes in Black and younger (<50) women. Similarly, triple negative BC, which carries the poorest prognosis and is mostly Basal-like, are overrepresented in Black and younger women. These variations in intrinsic subtype contribute to outcomes disparities. The extent to which these racial and age differences in subtypes and mortality occur in metastatic breast cancer (MBC) is unknown. Methods: HARMONY (NCT03769415) is a prospective clinical trial in patients with newly diagnosed MBC. Bulk tumor GEP (PAM50 intrinsic subtyping) is performed on primary and metastatic tumors. A primary objective is to determine the extent and treatment implications of molecular discordance (defined a priori as treatment differences by intrinsic subtype compared to clinical subtype); other endpoints to be reported later include GEP comparisons between primary and metastatic samples. Here we examine differences in a) intrinsic subtype and b) treatment patterns in MBC by race and age. Results: At the time of analysis, the study had accrued 220 participants. Mean age was 58, 24% were Black women. Sixty-five percent had HR+/HER2- MBC, 14% HER2-positive, and 21% triple negative. Unlike in early BC, LumB exceeded LumA (LumA 27%, LumB 35%, HER2-Enriched 12%, Basal-like 25%). Similar to early BC, subtype varied by race and age with more non-LumA subtypes in young and Black women. Discordance between intrinsic and clinical subtype was seen in 24% of Black, 20% of White women, in 29% of younger and 18% of older women. Treatment patterns also differed by race and age, where a higher percentage of younger Black women received first-line chemotherapy compared to younger White women overall (45% vs. 10%, p=0.0025), and in HR+/HER2- disease (33% vs 8.7%, p=>0.05). No difference was seen in older women (24% vs 17%, p=0.44). Median progression free survival was worst in younger Black women compared to all other participants (5.4 vs 19.5 months, p=0.027), which may be driven by clinical subtype. Conclusions: Intrinsic subtype of tumors in a metastatic population has a different distribution by race and age than early BC, with more poor-prognosis non-LumA subtypes, and approximately 1 in 5 have discordance between clinical and molecular subtype, which may be therapeutically relevant. Clinical trial information: NCT03769415 . [Table: see text]

DNA methylation differences in noncoding regions in ER negative breast tumors between Black and White women.

Incidence of estrogen receptor (ER)-negative breast cancer, an aggressive tumor subtype associated with worse prognosis, is higher among African American/Black women than other US racial and ethnic groups. The reasons for this disparity remain poorly understood but may be partially explained by differences in the epigenetic landscape. We previously conducted genome-wide DNA methylation profiling of ER- breast tumors from Black and White women and identified a large number of differentially methylated loci (DML) by race. Our initial analysis focused on DML mapping to protein-coding genes. In this study, motivated by increasing appreciation for the biological importance of the non-protein coding genome, we focused on 96 DMLs mapping to intergenic and noncoding RNA regions, using paired Illumina Infinium Human Methylation 450K array and RNA-seq data to assess the relationship between CpG methylation and RNA expression of genes located up to 1Mb away from the CpG site. Twenty-three (23) DMLs were significantly correlated with the expression of 36 genes (FDR<0.05), with some DMLs associated with the expression of single gene and others associated with more than one gene. One DML (cg20401567), hypermethylated in ER- tumors from Black versus White women, mapped to a putative enhancer/super-enhancer element located 1.3 Kb downstream of HOXB2. Increased methylation at this CpG correlated with decreased expression of HOXB2 (Rho=-0.74, FDR<0.001) and other HOXB/HOXB-AS genes. Analysis of an independent set of 207 ER- breast cancers from TCGA similarly confirmed hypermethylation at cg20401567 and reduced HOXB2 expression in tumors from Black versus White women (Rho=-0.75, FDR<0.001). Our findings indicate that epigenetic differences in ER- tumors between Black and White women are linked to altered gene expression and may hold functional significance in breast cancer pathogenesis.

Causal relationships between serum matrix metalloproteinases and estrogen receptor-negative breast cancer: a bidirectional mendelian randomization study

To better clarify the causal effects between matrix metalloproteinases (MMPs) and estrogen-receptor (ER)-negative breast cancer (BC), we investigated the bidirectional causal relationship between MMPs and ER-negative BC by mendelian randomization (MR) analysis. Summary statistic data of five MMPs were extracted from European participants in 13 cohorts. Data of ER-negative BC collected from one of genome-wide association studies of European ancestry was used as experimental datasets and another four ER-negative BC datasets were used as validation sets. Inverse variance weighted method was used for main MR analysis and sensitivity analysis was also conducted. Serum level of MMP-1 has negative effect on ER-negative BC (odds ratio = 0.92, P = 0.0008) but the latter one was not the cause of the former one, which was supported by validation sets. No bidirectional causal effect was detected between the other four types of MMPs and ER-negative BC (P > 0.05). Sensitivity analysis indicated robustness of the above results without remarkable bias. To conclude, serum MMP-1 may be a protective factor against ER-negative BC. No reciprocal causality was found between the other kinds of MMPs and ER-negative BC. MMP-1 was indicated as a biomarker for risk of ER-negative BC.

PREDICT validity for prognosis of breast cancer patients with pathogenic BRCA1/2 variants

We assessed the PREDICT v 2.2 for prognosis of breast cancer patients with pathogenic germline BRCA1 and BRCA2 variants, using follow-up data from 5453 BRCA1/2 carriers from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) and the Breast Cancer Association Consortium (BCAC). PREDICT for estrogen receptor (ER)-negative breast cancer had modest discrimination for BRCA1 carrier patients overall (Gönen & Heller unbiased concordance 0.65 in CIMBA, 0.64 in BCAC), but it distinguished clearly the high-mortality group from lower risk categories. In an analysis of low to high risk categories by PREDICT score percentiles, the observed mortality was consistently lower than the expected mortality, but the confidence intervals always included the calibration slope. Altogether, our results encourage the use of the PREDICT ER-negative model in management of breast cancer patients with germline BRCA1 variants. For the PREDICT ER-positive model, the discrimination was slightly lower in BRCA2 variant carriers (concordance 0.60 in CIMBA, 0.65 in BCAC). Especially, inclusion of the tumor grade distorted the prognostic estimates. The breast cancer mortality of BRCA2 carriers was underestimated at the low end of the PREDICT score distribution, whereas at the high end, the mortality was overestimated. These data suggest that BRCA2 status should also be taken into consideration with tumor characteristics, when estimating the prognosis of ER-positive breast cancer patients.

PET/CT in Patients with Breast Cancer Treated with Immunotherapy.

Significant advances in breast cancer (BC) treatment have been made in the last decade, including the use of immunotherapy and, in particular, immune checkpoint inhibitors that have been shown to improve the survival of patients with triple negative BC. This narrative review summarizes the studies supporting the use of immunotherapy in BC. Furthermore, the usefulness of 2-deoxy-2-[18F]fluoro-D-glucose (2-[18F]FDG) positron emission/computerized tomography (PET/CT) to image the tumor heterogeneity and to assess treatment response is explored, including the different criteria to interpret 2-[18F]FDG PET/CT imaging. The concept of immuno-PET is also described, by explaining the advantages of mapping treatment targets with a non-invasive and whole-body tool. Several radiopharmaceuticals in the preclinical phase are referred too, and, considering their promising results, translation to human studies is needed to support their use in clinical practice. Overall, this is an evolving field in BC treatment, despite PET imaging developments, the future trends also include expanding immunotherapy to early-stage BC and using other biomarkers.

Reduced Expression of RBP7 is Associated with Resistance to Tamoxifen In Luminal A Breast Cancer.

Tamoxifen is the most commonly used hormonal treatment for ERα-positive breast cancer. Tamoxifen resistance is still a big problem for ERα target therapy. RBP7 is a member of the cellular retinol-binding protein family. This study aims to investigate the prognostic role of RBP7 and the relationship between RBP7 expression and sensitivity or resistance to tamoxifen in ERα-positive breast cancer. A bioinformatics method was used to investigate RBP7 expression and the prognostic value of RBP7 in different subtypes of breast cancer. The relationship between RBP7 expression and sensitivity or resistance to tamoxifen was studied using clinical data (GSE1379) and cell line data (GSE27473, GSE2645923, GSM3715281, and GSM3715282). Transfection of RBP7 experiments was used to testify to the function of RBP7 in MCF7 cell. RBP7 is a member of the family of cellular retinol-binding proteins. RBP7 expression was down-regulated at both mRNA and protein levels in breast cancer and was not associated with different TNM (Tumor, Node, Metastasis) stages. High expression of RBP7 was significantly related to good relative percent survival in the luminal A subtype, but in negative breast cancer, the result was opposite. The ROC plot showed that RBP7 had a significant predictive value for the tamoxifen response in the luminal A subtype. The expression of RBP7 from patients with recurrence treated with tamoxifen was significantly reduced. Gene Expression Omnibus showed that RBP7 expression was reduced considerably in tamoxifen-resistant MCF7 cells and T47D cells. The expression of RBP7 was positively correlated with some microRNAs involved in negatively regulating tamoxifen-resistant breast cancer. We also found that the expression of RBP7 decreased significantly in tamoxifen-resistant MCF7 cells, and transfection of RBP7 increased the sensitivity of resistant cells to tamoxifen. Reduced expression of RBP7 is associated with resistance to tamoxifen in luminal A breast cancer. Our research may help to explore the mechanisms of resistance of breast cancer to tamoxifen.

Palbociclib in Acute Leukemias With KMT2A-rearrangement: Results of AMLSG 23-14 Trial.

Palbociclib in Acute Leukemias With KMT2A-rearrangement: Results of AMLSG 23-14 Trial.

Targeted Therapies and the Evolving Standard of Care for Triple-Negative and Germline BRCA1/2-Mutated Breast Cancers in the High-Risk, Early-Stage Setting.

Immune checkpoint inhibitors (ICIs) and poly (ADP-ribose) polymerase (PARP) inhibitors have transformed the treatment landscape of metastatic triple-negative breast cancer (TNBC). Trial results have demonstrated the clinical benefit of these targeted agents in the advanced TNBC setting and have led to their evaluation in the treatment of high-risk, early-stage TNBC and BRCA-mutated breast cancer. We provide a summary of the results that have led to the establishment of the ICI pembrolizumab and the PARP inhibitor olaparib as new standards of care. Using PubMed, we searched for original articles published in English between 2017 and 2022. Search terms included triple-negative breast cancer, adjuvant, neoadjuvant, immunotherapy, and PARP inhibitors. Two targeted therapies have been approved by the US Food and Drug Administration for the treatment of TNBC and BRCA-mutated breast cancers in the high-risk, early-stage setting on the basis of clinical trial results demonstrating improved clinical outcomes. For high-risk, early-stage TNBC, pembrolizumab was approved as neoadjuvant therapy in combination with chemotherapy and as a single agent for continued treatment after surgery; this approval was based on results of the KEYNOTE-522 trial. Olaparib was approved for the adjuvant treatment of patients with high-risk, early-stage human epidermal growth factor receptor type 2 (HER2)-negative breast cancer with germline BRCA1/2 mutations who have been previously treated with neoadjuvant or adjuvant chemotherapy on the basis of the OlympiA trial results. Clinical trial results demonstrate the pronounced clinical benefits of pembrolizumab combined with chemotherapy for high-risk, early-stage TNBC and adjuvant olaparib for high-risk, early-stage HER2-negative BRCA1/2-mutated breast cancer.

208P Clinical characteristics and prognostic factors in patients with breast cancer and leptomeningeal metastases: A subanalysis of the German brain metastases in breast cancer registry (BMBC)

Leptomeningeal metastases (LM) in patients with breast cancer (BC) is rare but associated with poor prognosis. Specific factors associated with prognosis of patients with LM have not been characterized in a large patient cohort. We aimed to evaluate prognostic factors in BC patients with LM from the Brain Metastases in Breast Cancer (BMBC) Registry. Patient’s and tumor’s main features were retrieved from the BMBC. Median overall survival (mOS) was defined as the time from first diagnosis of central nervous system metastases (CNS) to death from any cause. Median progression-free survival (mPFS) was defined as the time from first diagnosis of CNS to progression in CNS, extracranial metastases or death. A total of 781 patients with LM and BC were included in the analysis (781/3858, prevalence of 20.2%). 354 (45.3%) patients had LM without BM. A mPFS was3.9 months (95%CI 3.4-4.5) and a mOS was 4.9 months (95% 4.3-5.7). Older age (>=60 vs. <60 years, HR 2.07, 95%CI 1.53-2.79) and a worse ECOG performance status (2-4 vs. 0-1 HR 2.03, 95% CI 1.52-2.71) were significantly associated with a higher risk of death in the multivariate analysis. Endocrine treatment (for hormone-receptor-positive BC) was significantly associated with a lower risk of death (HR 0.43 95%CI 0.28-0.65). Also, whole brain radiotherapy was associated with a lower risk of death (HR 0.62 95%CI 0.45-0.87). Furthermore, BC subtype correlated significantly with prognosis in patients with LM. Patients with luminal-like BC and patients with a triple negative BC had a significant higher risk of death than patients with a triple-positive BC (HR 1.55, 95%CI 1.05-2.28 resp. HR 2.47, 95%CI 1.59-3.85). Additional analyses, including a comparison with patients without LM in the BMBC cohort will be presented. Patients with LM have a short survival. The identified prognostic factors can support the clinicians to identify the group of patients with a better survival who could possibly benefit from a more intense treatment regimen. Financial support for the management of BMBC Registry was provided by an unrestricted research grant from Daiichi Sankyo to GBG.

Relationship between food-derived antioxidant vitamin intake and breast cancer risk: a mendelian randomized study.

In previous observational studies, food-derived antioxidant vitamins have been suggested to be associated with breast cancer. However, the findings were inconsistent and the causal relationship could not be clearly elucidated. To confirm the potential causal relationship between food-derived antioxidants (retinol, carotene, vitamin C and vitamin E) and the risk of breast cancer, we conducted a two-sample Mendelian randomization (MR) study. The instrumental variables (IVs) as proxies of genetic liability to food-derived antioxidant vitamins were obtained from the UK Biobank Database. We extracted breast cancer data (122,977 cases and 105,974 controls) from the Breast Cancer Consortium (BCAC). In addition, we studied estrogen expression status categorically, including estrogen receptor positive (ER+) breast cancer (69,501 cases and 105,974 controls) and versus estrogen receptor (ER-) negative breast cancer (21,468 cases and 105,974 controls). We performed two-sample Mendelian randomization study, and inverse variance-weighted (IVW) test was regarded as main analysis. Sensitivity analyses were further conducted to assess heterogeneity and horizontal pleiotropy. The results of IVW showed that among the four food-derived antioxidants, only vitamin E had protective effect on the risk of overall breast cancer (OR = 0.837, 95% CI 0.757-0.926, P = 0.001) and ER+ breast cancer (OR = 0.823, 95% CI 0.693-0.977, P = 0.026). However, we found no association between food-derived vitamin E and ER- breast cancer. Our study suggested food-derived vitamin E can decrease the risk of breast cancer overall and ER+ breast cancer, and the robustness of our results was confirmed by sensitivity analyses.

Adjuvant chemotherapy is associated with an overall survival benefit regardless of age in ER+/HER2- breast cancer pts with 1-3 positive nodes and oncotype DX recurrence score 20 to 25: an NCDB analysis.

The RxPONDER trial found that among breast cancer patients with estrogen receptor positive (ER+) breast cancer, 1-3 positive axillary nodes, and a recurrence score of ≤25, only pre-menopausal women benefitted from adjuvant chemoendocrine therapy; postmenopausal women with similar characteristic did not benefit from adjuvant chemotherapy. We aimed to replicate the RxPonder trial using a larger patient cohort with real world data to determine whether a RS threshold existed where adjuvant chemotherapy was beneficial regardless of age. The National Cancer Database (NCDB) was queried for women with ER+, human epidermal growth factor receptor 2 (HER2) negative breast cancer, 1-3 positive axillary nodes, and RS ≤25 who received endocrine (ET) only or chemo-endocrine therapy (CET). Cox regression interaction was explored between CET and age as a surrogate for menopausal status. The final analytic cohort included 28,427 eligible women: 7,487 (26.3%) received adjuvant CET and 20,940 (73.7%) ET. In the entire cohort, RS had a normal distribution, with a median score of 14. After correcting for demographic and clinical variables, a threshold effect was observed with RS >20 being associated with a significantly inferior overall survival (OS) (P value range: < 0.001-0.019). In women with RS of 20-25, CET was associated with a significant improvement in OS compared to ET alone, regardless of age (age <=50: HR = 0.334, P=0.002; age>50: HR=0.521, P=0.019). Among women with ER+/HER2- breast cancer with 1-3 positive nodes, and a RS of 20-25-in contrast to the RxPONDER trial-we observed that CET was associated with an OS benefit in women regardless of age.

Hiệu quả điều trị nội tiết kết hợp thuốc ức chế CDK4/6 trên bệnh nhân ung thư vú tái phát di căn thụ thể nội tiết dương tính, HER2 âm tính

TÓM TẮT Mục tiêu: Mô tả đặc điểm lâm sàng, cận lâm sàng cũng như đánh giá hiệu quả của điều trị nội tiết kết hợp thuốc ức chế CDK4/6 trên bệnh nhân ung thư vú tái phát di căn thụ thể nội tiết dương tính, HER2 âm tính. Đối tượng, phương pháp: Nghiên cứu mô tả hồi cứu kết hợp tiến cứu trên 61 bệnh nhân được chẩn đoán ung thư biểu mô tuyến vú tái phát di căn thụ thể nội tiết dương tính, HER2 âm tính tại Bệnh viện K từ tháng 01/2020 tới tháng 10/2022. Kết quả: Tuổi trung bình ở thời điểm tái phát, di căn là 54,0 tuổi. Đa số bệnh nhân tái phát sau 2 năm điều trị triệt căn chiếm 75%. Các vị trí di căn thường gặp lần lượt là xương, phổi và gan chiếm tỷ lệ 70,5%, 36,0% và 24,6%. Tỷ lệ đáp ứng chung của phác đồ là 45,9%; trong đó 1,6% đáp ứng hoàn toàn, đáp ứng một phần là 44,3%, bệnh giữ nguyên là 31,1%. Tỷ lệ đáp ứng ở nhóm điều trị phác đồ bước 1 và bước sau lần lượt là 58,8% và 29,6%, sự khác biệt có ý nghĩa thống kê với p = 0,023. Trung vị thời gian sống thêm bệnh không tiến triển là 17 tháng. Kết luận: Điều trị nội tiết kết hợp thuốc ức chế CDK4/6 trên nhóm bệnh nhân ung thư vú tái phát di căn thụ thể nội tiết dương tính, HER2 âm tính cho tỉ lệ đáp ứng, thời gian sống thêm bệnh không tiến triển cao do vậy phác đồ có thể được sử dụng rộng rãi hơn trong thực hành lâm sàng. ABSTRACT THE EFFICACY OF ENDOCRINE COMBINED WITH CDK4/6 INHIBITORS IN PATIENTS WITH HORMONE RECEPTOR - POSITIVE, HER2 - NEGATIVE RECURENT OR METASTATIC BREAST CANCER Objectives: To evaluate the efficacy of endocrine combined with CDK4/6 inhibitors in patients with hormone receptor - positive, HER2 - negative recurrent or metastatatic breast cancer. Methods: A retrospective and prospective descriptive study on 61 patients diagnosed with hormone receptor - positive, HER2 - negative metastatic or recurrent breast cancer at K Hospital from January 2020 to October 2022. Result: The mean age was 54.0 years. The majority of patients relapsed after 2 years of radical treatment, accounting for 75%. The most common metastatic sites were bone, lung and liver, respectively, accounting for 70.5%, 36.0% and 24.6%. The overall response rate of the regimen was 45.9%. The complete response rate was 1.6%, the partial response rate was 44.3%, 31.1% of the patients were stable. The overall response rate in first - line therapy was better than that in the second - line of treatment (ORR: 67,5% vs 37,5%; p = 0,039). The response rate in the first line and subsequent lines were 58.8% and 29.6%, respectively, the difference was statistically significant with p = 0.023. Median progression - free survival was 17 months. Conclusion: Endocrine combined with CDK4/6 inhibitors is effective in high response rates and progression - free survival for patients with recurrent or metastatic of hormone receptor - positive, HER2 - negative breast cancer. This regimens may be more widely used in clinical practice.

The CDK4/6 Inhibitor Palbociclib Inhibits Estrogen-Positive and Triple Negative Breast Cancer Bone Metastasis In Vivo

CDK 4/6 inhibitors have demonstrated significant improved survival for patients with estrogen receptor (ER) positive breast cancer (BC). However, the ability of these promising agents to inhibit bone metastasis from either ER+ve or triple negative BC (TNBC) remains to be established. We therefore investigated the effects of the CDK 4/6 inhibitor, palbociclib, using in vivo models of breast cancer bone metastasis. In an ER+ve T47D model of spontaneous breast cancer metastasis from the mammary fat pad to bone, primary tumour growth and the number of hind limb skeletal tumours were significantly lower in palbociclib treated animals compared to vehicle controls. In the TNBC MDA-MB-231 model of metastatic outgrowth in bone (intracardiac route), continuous palbociclib treatment significantly inhibited tumour growth in bone compared to vehicle. When a 7-day break was introduced after 28 days (mimicking the clinical schedule), tumour growth resumed and was not inhibited by a second cycle of palbociclib, either alone or when combined with the bone-targeted agent, zoledronic acid (Zol), or a CDK7 inhibitor. Downstream phosphoprotein analysis of the MAPK pathway identified a number of phosphoproteins, such as p38, that may contribute to drug-insensitive tumour growth. These data encourage further investigation of targeting alternative pathways in CDK 4/6-insensitive tumour growth.

Abstract 4675: Chemoresistant patient-derived xenografts to identify treatment options in breast cancer patients not responding to standard chemotherapy

Abstract Resistance to chemotherapy is a major clinical challenge in breast cancer (BC), and patients developing resistance need treatment alternatives. In this project we utilize patient-derived xenografts (PDXs) from triple negative BC (TNBC), as these models better reflect the human tumor complexity and heterogeneity, compared to cell line-based- and transgene animal models. An in-house established orthotopically growing PDX, MAS98.12, has gained resistance to chemotherapy due to prolonged exposure to paclitaxel (MAS98.12-PR), a microtubule-targeting chemotherapeutic agent. As the resistance was obtained in animals, we also have the paclitaxel sensitive equivalent (MAS98.12-PS). By utilizing the pair of sensitive and resistant tumors we can study the corresponding mechanism evolving in patients who initially respond to chemotherapy before resistance and disease progression. This model will aid in identifying key mechanisms of survival in the resistant tumors, and eventually in identifying targets for use as novel therapeutic opportunities in TNBC patients resistant to standard therapy. Finally, we have samples collected early and late after resistance development, allowing us to characterize mechanisms involved in stepwise progression of paclitaxel resistance. We are currently performing molecular profiling to reveal the mechanisms involved in development of resistance. Data from bulk RNAseq, immune profiling of myeloid cells, exome sequencing, secretome profiling and reverse-phase protein array (RPPA) allow for characterizing the isogenic pair of tumors on multiple levels. Preliminary observations include aberrant expression of ABCB1/MDR1, normally involved in translocating drugs across membranes, and previously described as a mechanism involved in pertaining resistance in tumor cells. As multiple attempts to target MDR1 itself has failed, we hypothesize that our PS and PR pair will identify vulnerable/targetable signaling axis in the resistant tumors. Additionally, both PDX models have been assessed for their sensitivity to various chemo-/targeted-drugs and their combinations, revealing alternative means of treating the resistant tumors. Altogether, the molecular profiles and the sensitivity data will give novel knowledge and treatment options for patients failing to respond to standard chemotherapy. Citation Format: Eivind Valen Egeland, Kotryna Seip, Geir Frode Øy, Eleni Skourti, Solveig J Pettersen, Siri Juell, Mads Haugland Haugen, Olav Engebraaten, Lina Prasmickaite, Gunhild M Maelandsmo. Chemoresistant patient-derived xenografts to identify treatment options in breast cancer patients not responding to standard chemotherapy. [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 4675.

Abstract 2247: Evaluation of multidrug resistant genes among breast cancer patients in Ghana

Abstract Background: Breast cancer (BC) is a leading cause of cancer death in Ghana and around the world. Ghanaian women are diagnosed at younger ages with the more aggressive Triple Negative BC (TNBC) subtype where West African ancestry is associated with advanced BC diagnosis and higher mortality rates compared to age-matched women of European ancestry. Genomic comparisons of BC tumors from women of African and European ancestry show differences in frequencies of single nucleotide polymorphisms (SNP) and copy number variations. These differences may contribute to disparities in disease and treatment outcomes observed in women of African ancestry. Chemotherapy plays a major role in treatment of recurrent and metastatic BC. Long-term BC survival remains poor especially in Africa due to multidrug resistance (MDR). MDR has been associated with binding cassette (ABC) protein transporters. ABCB1, ABCC1 and ABCG2 are ABC transporter genes that code for proteins involved in drug efflux. We hypothesize that SNPs in ABC transporter genes may alter their physiological protective role and increase risk of MDR, treatment failure and death among BC patients. Preliminary dataWe explored gene expression profiles of ABCB1, ABCC1 and ABCG2 in an African ancestry-enriched subset of women with TNBC (ICSBCS cohort: Ghanaian n = 6, African American (AA) n = 9, Ethiopian n = 11). Preliminary data showed significantly higher expression of ABCC1 among Ghanaian and AA patients compared to Ethiopians, and a significant positive correlation with African ancestry. ABCB1 and ABCG2 showed lower expression in all three groups (ns).To study the relationship between ABC transporter gene SNPs and MDR, we have collected data over a 3-year period (2019-2021) from the Oncology Department of the Komfo Anokye Teaching Hospital in Ghana. The overall prevalence of BC recurrence was 3.4% (CI = 2.5 - 4.7%), and prevalence of metastatic BC was 47.6% (CI = 44.6 - 50.6%). Methodology: SNPs in ABC transporter genes will be obtained from 150 consented female BC patients who have undergone chemotherapy. We will compare genotype frequencies among patients with disease recurrence and/or metastasis (n = 100) to those with no disease recurrence or metastasis (n = 50). Single-plex genotyping of the ABC gene SNPs will be completed using a real-time PCR allelic discrimination assay. Conclusion: ABCC1 has been established to be associated with African ancestry. Determining the association of ABC gene SNPs and MDR among Ghanaian BC patients will provide further information on allelic variants and their effects on BC treatment outcomes. Citation Format: Gloria Agyekum Boaitey, Rachel Martini, Melissa B. Davis, Lisa Newman, Brian Stonaker, Linda Ahenkorah Fondjo, Christian Obirikorang, Ernest Osei Bonsu, Ernest Adjei, Ishmael Kyei, Mavis Bobie Ansah, Mahteme Bekele, Timothy Chu, Nicolas Robine. Evaluation of multidrug resistant genes among breast cancer patients in Ghana [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 2247.

Abstract 2154: Differential expression of the PI3K-Akt signaling pathway pre and post chemotherapy in relation to hormonal profile in African women

Abstract Background: Breast cancer (BC) is the most common cancer in US and Canadian women. Despite therapeutic advances, it remains the second leading cause of female cancer mortality. Aggressive breast cancers are represented as a clinical (inflammatory BC or locally advanced BC) or as a biopathological form (triple negative BC or HER2+ BC). These aggressive forms have a poor prognosis. In the US, African Americans have a 41% higher BC death rate than Caucasians women. As observed in the US, in African Gabon women, a more aggressive and cases of triple negative BC are found. Aggressive BC are mainly associated with African women. At this stage, chemotherapy is the main therapeutic treatment but chemoresistance is the major hurdle. One solution to chemoresistance would be to found candidates biomarkers that predict therapeutic responses. The goal of our study was to establish an RNA signature that could differentiate chemosensitive from chemoresistant patients in BC African women. Methods: RNA sequencing technique was used to establish expression profiling in African women before and after chemotherapy using three groups of aggressive BC patients treated with: Doxorubicin, 5-Fluorouracil or Navelbine. We first isolated RNA from tissues fixed in paraffin and sequenced it via the Nextseq 2000 system. A tximport (v1.20.0) and DESeq2 (v1.26.0) analysis then identified significantly and differentially expressed transcripts between the different groups. Results: In the doxorubicin group, post-chemotherapy patients had 962 significant genes out of the 46461 transcripts compared to pre-chemotherapy patients. The post-chemotherapy 5-FluoroUracil group had 3723 significant genes out of 43821 transcripts compared to pre-chemotherapy Fluorouracil group and the post-chemotherapy Navelbine group had 980 significant genes out of 44689 transcripts compared to pre-chemotherapy Navelbine group. Relevant overexpressed genes were selected for validation by immunohistochemistry (IHC). We found an enrichment in the KEGG and PI-3K/Akt pathways and observed that Akt downstream substrates were express differently between pre- and post-chemotherapy patients. Conclusion: Our study suggests that some of the overexpressed post chemotherapy genes could serve as biomarkers of aggressive BC. This is the first study in Canada to investigate Doxorubicin, Flurouracile and Navelbine chemoresistance-related genes in African women and could lead to the discovery of diagnostic markers and therapeutic targets. Citation Format: Hurette Junie Chansi Kengni. Differential expression of the PI3K-Akt signaling pathway pre and post chemotherapy in relation to hormonal profile in African women [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 2154.

Abstract 1940: Outcomes of patients treated with neoadjuvant chemotherapy for breast cancer at a safety net hospital

Abstract Background: Neoadjuvant chemotherapy (NAC) is administered before surgery and expected to benefit certain breast cancer (BC) patients (pts). This study inspected outcomes of triple negative BC (TNBC), hormone receptor (HR) positive (+) HER2 negative (-), and HER2+ BC pts treated with NAC at John Peter Smith Hospital (JPS) in Tarrant County, TX. Methods: It is an IRB exempted retrospective review of JPS Oncology and Infusion Center’s registry data. Eligible pts were diagnosed with TNBC, HR+ HER2-, or HER2+ BC from 1/1/2016 to 12/31/2019 and underwent NAC. Age, race, NAC regimen, tumor grade, recurrence, and pt survival were collected from EPIC EMR. NCCN guidelines were used to standardize clinical prognostic and pathologic anatomic stages. Decrease in stage by at least one level was considered as improvement. Results: Refer to table for additional results. Total of 104 pts. 22 (21.2%) had recurrence, 14 (14.5%) had died. Using the full cox proportional hazard model, TNBC pts had a 3.214 times higher hazard of death/recurrence compared to other subsets (95% CI: 1.261, 8.193; p= 0.0145). 70 (67.3%) pts showed improvement in stage. 34 (32.7%) achieved pathological complete response (pCR). When compared to pts with residual disease, achieving pCR reduced hazard of death/recurrence by 71.6% (HR: 0.284; 95% CI: 0.095, 0.849; p= 0.0243). Conclusion: A clear unmet need is poor survival of Black TNBC pts. Safety net hospitals, like JPS, disproportionately treat Black pts. We show that attaining pCR correlates with improved survival, but less than a quarter of TNBC pts attained pCR. New NAC regimens with Pembrolizumab has become standard of care for TNBC pts since 2021 due to higher pCR rates. Still, there is a need for better NAC regimens to improve pCR in TNBC overall and clinical trials on new regimens should include Black pts. Also, more than a third of HR+ HER2- pts upstaged in LN after NAC. This suggests a need for pre-NAC radiology staging methods and better NAC regimen testing for this subset. TNBC(32 patients) HR+, HER2-(29 patients) HER2+(43 patients) TOTAL(104 patients, 103 women) Median Age Median Age 58 50 53 53 Racial Distribution of Patients Non-Hispanic White 9(28.1%) 11(37.9%) 11(25.6%) 31(29.8%) Black 18(56.3%) 12(41.4%) 15(34.9%) 45(43.3%) Hispanic 4(12.5%) 2(6.9%) 10(23.3%) 16(15.4%) Asian 1(3.1%) 4(13.8%) 7(16.3%) 12(11.5%) Clinical Prognostic Stage Before NAC and Surgery 1 1(3.1%) 0(0%) 9(20.9%) 10(9.6%) 2 8(25%) 13(44.8%) 20(46.5%) 30(28.8%) 3 22(68.8%) 16(55.2%) 14(32.6%) 52(50%) 4 1(3.1%) 0(0%) 0(0%) 1(0.9%) Pathologic Anatomic Stage After NAC and Surgery pCR 7(21.9%) 3(10.3%) 24(55.8%) 34(32.7%) 1 8(25%) 3(10.3%) 14(32.6%) 24(23.1%) 2 9(28.1%) 9(31%) 3(7%) 21(20.2%) 3 8(25%) 14(48.3%) 2(4.7%) 24(23.1%) 4 0(0%) 0(0%) 0(0%) 0(0%) Tumor Stage Difference Before/After Surgery Improvement 24(75%) 11(37.9%) 35(81.4%) 70(67.3%) Deterioration 1(3.1%) 7(24.1%) 0(0%) 8(7.7%) No Change 7(21.9%) 11(37.9%) 8(18.6%) 26(25%) Recurrence Recurrence 10(31.3%) 4(13.8%) 8(18.6%) 22(21.2%) Patients survived as of 9/19/2022 Survival 25(78.1%) 27(93.1%) 38(88.4%) 90(86.5%) Additional Significant Results Completion of NAC regimen 89 (85.6%) total pts Lymph Node (LN) Upstaging for HR+ HER2- 6 (20.7%) pts showed improvement in LN while 11 (37.9%) upstaged in LN pCR in Black TNBC pts Only 16% of Black pts achieved pCR Citation Format: Prakriti Srivastava, James-Michael Blackwell, Jolonda Bullock, Riyaz Basha, Kalyani Narra. Outcomes of patients treated with neoadjuvant chemotherapy for breast cancer at a safety net hospital [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 1940.

Abstract 3080: Characterization of steroid receptor mediated activation of GLI as driving force of breast cancer growth

Abstract Background: Hedgehog (Hh) signaling pathway plays a fundamental role in the early stages of development by regulating morphogenesis. GLI transcription factors are drivers of this signaling pathway by regulating the expression of growth related genes. Hyperactivation of GLI proteins have been associated with several cancers including medulloblastoma, glioblastoma, ovarian, prostate and breast cancers. Our study in breast cancer (BCa) suggests transcriptional activation of GLI3 in estrogen receptor alpha (ERα) positive cells upon estradiol stimulation. Loss of ERα greatly decreases GLI3 protein stability and stimulation with estradiol significantly increases GLI3 stability in ER-positive BCa cells. We have discovered that GLI3 forms nuclear complexes with ERα upon estradiol stimulation and that the loss of GLI3 reduces BCa cells growth. Therefore, we hypothesize that ERα-GLI3 complex orchestrates BCa transcriptome required for cell growth and development. Our study focuses on characterizing ERα mediated activation of GLI3 in BCa cells and the possible compensation by other steroid receptors such as the androgen receptor (AR) and the glucocorticoid receptor (GR) in ER-negative BCa cells. Method: We examined ERα- GLI transcriptional activity by RNA sequencing upon stimulation with estradiol and inhibition of GLI activity by GANT61 in ER-positive MCF7 cells. We also identified ERα domains that are essential for GLI3 binding by immunoprecipitation and proximity ligation assay (PLA). To identify ERα-GLI3 interactome, we have optimized Rapid Immunoprecipitation Mass Spectrometry of Endogenous protein (RIME). We also examined the role of GLI3 in ER-negative BCa cell growth and characterized the role of AR and GR in activating GLI3 by luciferase reporter assay.Results: Inhibition of GLI DNA binding by GANT61 reduced the expression of GLI regulated (CDC20, CDK1, UBE2C) and modified expression of ERα regulated (FOXM1, SPC24, KIF20A, BIRC5) genes, suggesting cooperative role of ERα-GLI3 in mediating growth and metastasis. The optimized RIME assay suggests immunoprecipitation of ERα with GLI3 in BCa cells upon estradiol induction. Immunoprecipitation and PLA studies suggest that ERα-N terminal, DNA binding and C-terminal domains interact with GLI3. We also showed that knockdown of GLI3 reduces growth in ER negative BCa cells and that AR or GR stimulation by dihydrotestosterone and dexamethasone respectively, are important for GLI3 transcriptional activity. Conclusion: Collectively, our results suggest a new role of steroid receptors in regulating GLI oncogenic transcriptional activity in BCa, leading to new therapeutic possibilities for patients. Citation Format: Shabnam Massah, Maria Guo, Jane Foo, Ralph Buttyan, Artem Cherkasov, Nada Lallous. Characterization of steroid receptor mediated activation of GLI as driving force of breast cancer growth [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 3080.

High expression of TLR3 in triple-negative breast cancer predicts better prognosis—data from the Fudan University Shanghai Cancer Center cohort and tissue microarrays

IntroductionWe have previously reported that Toll-like receptor 3 (TLR3) acts as a suppressor gene for breast cancer initiation and progression. In this study, we evaluated the role of TLR3 in breast cancer using our original Fudan University Shanghai Cancer Center (FUSCC) datasets and breast cancer tissue microarrays.MethodsUsing FUSCC multiomics datasets on triple- negative breast cancer (TNBC), we compared the mRNA expression of TLR3 in TNBC tissue and the adjacent normal tissue. A Kaplan–Meier plotter was performed to investigate the expression of TLR3 on prognosis in the FUSCC TNBC cohort. We performed immunohistochemical staining to analyze TLR3 protein expression in the TNBC tissue microarrays. Furthermore, bioinformatics analysis was performed using the Cancer Genome Atlas (TCGA) data to verify the results of our FUSCC study. The relationship between TLR3 and clinicopathological features was analyzed with logistic regression and the Wilcoxon signed-rank test. The association between clinical characteristics and overall survival in TCGA patients was assessed using the Kaplan–Meier method and Cox regression analysis. Gene set enrichment analysis (GSEA) was performed to identify signaling pathways that are differentially activated in breast cancer.ResultsThe mRNA expression of TLR3 was lower in TNBC tissue than in the adjacent normal tissue in the FUSCC datasets. The TLR3 had high expression in immunomodulatory (IM) and mesenchymal-like (MES) subtypes and low expression in luminal androgen receptor (LAR) and basal-like immune-suppressed (BLIS) subtypes. High expression of TLR3 in TNBC predicted better prognosis in the FUSCC TNBC cohort. Immunohistochemical staining of the tissue microarrays showed that TLR3 had lower expression in breast cancer tissues than in the adject normal tissues. Furthermore, the TLR3 expression was positively associated with B cell, CD4 + T cells, CD8 + T cells, neutrophils, macrophages, and myeloid dendritic cells. Bioinformatic analysis using high-throughput RNA-sequencing data from the TCGA demonstrated that the reduced expression of TLR3 in breast cancer was associated with advanced clinicopathological characteristics, survival time, and poor prognosis.ConclusionsTLR3 has low expression in TNBC tissue. High expression of TLR3 in triple-negative breast cancer predicts better prognosis. TLR3 expression may be a potential prognostic molecular marker of poor survival in breast cancer.

Elacestrant: First Approval.

Elacestrant (ORSERDU™) is an orally available selective estrogen receptor degrader (SERD) being developed by Stemline Therapeutics, a subsidiary of Menarini Group, for the treatment of estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. In January 2023, elacestrant received its first approval for the treatment of postmenopausal women or adult men with ER-positive, HER2-negative, estrogen receptor 1 (ESR1)-mutated (as determined by a US FDA-approved test) advanced or metastatic breast cancer with disease progression following ≥ 1line of endocrine therapy in the USA. A regulatory assessment of elacestrant for the treatment of ER-positive, HER2-negative advanced or metastatic breast cancer is currently underway in the EU. Development of elacestrant for the treatment of vasomotor symptoms has been discontinued. This article summarizes the milestones in the development of elacestrant leading to this first approval for this indication.