Metastatic Breast Research Articles

Correction: Cost-effectiveness of talazoparib for patients with locally advanced or metastasized breast cancer in Germany

Correction: Cost-effectiveness of talazoparib for patients with locally advanced or metastasized breast cancer in Germany

The cellular localization and oncogenic or tumor suppressive effects of angiomiotin-like protein 2 in tumor and normal cells.

Angiomiotin (AMOT) family comprises three members: AMOT, AMOT-like protein 1 (AMOTL1), and AMOT-like protein 2 (AMOTL2). AMOTL2 is widely expressed in endothelial cells, epithelial cells, and various cancer cells. Specifically, AMOTL2 predominantly localizes in the cytoplasm and nucleus in human normal cells, whereas associates with cell-cell junctions and actin cytoskeleton in non-human cells, and locates at cell junctions or within the recycling endosomes in cancer cells. AMOTL2 is implicated in regulation of tube formation, cell polarity, and shape, although the specific impact on tumorigenesis remains to be conclusively determined. It has been shown that AMOTL2 enhances tumor growth and metastasis in pancreatic, breast, and colon cancer, however inhibits cell proliferation and migration in lung, hepatocellular cancer, and glioblastoma. In addition to its role in cell shape and cytoskeletal dynamics through co-localization with F-actin, AMOTL2 modulates the transcription of Yes-associated protein (YAP) by binding to it, thereby affecting its phosphorylation and cellular sequestration. Furthermore, the stability and cellular localization of AMOTL2, influenced by its phosphorylation and ubiquitination mediated by specific proteins, affects its cellular function. Additionally, we observe that AMOTL2 is predominantly downregulated in some tumors, but significantly elevated in colorectal adenocarcinoma (COAD). Moreover, overall analysis, GSEA and ROC curve analysis indicate that AMOTL2 exerts as an oncogenic protein in COAD by modulating Wnt pathway, participating in synthesis of collagen formation, and interacting with extracellular matrix receptor. In addition, AMOTL2 potentially regulates the distribution of immune cells infiltration in COAD. In summary, AMOTL2 probably functions as an oncogene in COAD. Consequently, further in-depth mechanistic research is required to elucidate the precise roles of AMOTL2 in various cancers.

Abstract PO4-07-11: FDG-PET is superior to bone scintigraphy for the detection of bone metastases in breast cancer patients

Abstract Background: Bone is the commonest site for metastases in breast cancer patients, with up to 44% of patients having bone as their sole site of metastatic disease. Patients are at increased risk of morbidity from skeletal related events (SRE) from bone metastases due to pathological fractures and spinal cord compression. Early diagnosis is crucial so that bone modifying agents can be used to prevent SREs and other agents such as CDK4/6 inhibitors can be considered. Bone scintigraphy is the most widely performed first investigation for patients at high risk or symptomatic from bone metastases. Methods: We performed a meta-analysis comparing FDG-PET and bone scintigraphy using PubMed, Science Direct, and Embase for the literature search. 1009 patients were included in the study. Data for 2 × 2 contigency tables was selected and QUADAS-2 was used for quality assessment. Diagnostic accuracy was performed using Graph pad Prism 9.5.1 and R studio 2022. Pooled sensitivity and specificity of FDG-PET/CT was 96.6% (95% CI=91.5%-98.7%) and 96.8% (95% CI=82.1%-99.5%) respectively. Respective results for BS were 88.3% (95% CI=79.8%-93.5%) and 81.3% (95% CI=63.1%-91.7%). Sensitivity and specificity of FDG-PET/CT was significantly higher than BS (P=0.0063, P= 0.0068, respectively). The diagnostic odds ratio and area under ROC curve were significantly higher for FDG-PET/CT than BS (654.36 vs 35.24, and 0.980 vs 0.877, respectively). Conclusion: FDG-PET is superior to bone scinitigaphy for the detection of bone metastases in breast cancer.The benefits of replacing BS with FDG-PET/CT are evident. However othere technologies such as DW-MRI should be considered. Large multicentre prospective trials with strict FDG-PET/CT imaging protocols compared to DW-MRI both for disease detection and monitoring of response are required to strengthen the evidence in this field, to help inform imaging guidelines and best practices in the future. Newer technologies such as [18F]estradiol (FES)-PET and [18F]GE-226 for HER2 expression also warrant further investigation in ER positive and HER2 positive breast cancer. Citation Format: Laura Kenny, Maisher Tin-U. FDG-PET is superior to bone scintigraphy for the detection of bone metastases in 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 PO4-07-11.

Abstract PO5-18-06: On-going phase 1A clinical trial of A01, a chimerized monoclonal antibody to Progranulin/Glycoprotein 88 (GP88) in patients with advanced malignancy

Abstract Progranulin (PGRN/GP88) is an 88 kDa glycoprotein characterized by seven and a half double cysteine rich repeats which is the largest member of the granulin-epithelin protein family. PGRN/GP88 has been demonstrated as a biological driver of tumorigenesis, survival, and drug resistance in several cancers including breast cancer (BC), lung prostate, ovarian and digestive cancers. PGRN/GP88 tissue expression is an independent prognostic factor of recurrence in breast, lung cancers while elevated serum PGRN/GP88 level in metastatic breast, lung, ovarian and prostate cancer patients. Elevated PGRN/GP88 levels are associated with poor outcomes such as progression and shortened survival. An anti-human PGRN/GP88 monoclonal antibody able to inhibit the the in vitro and in vivo action of human PGRN/GP88 has been developed, chimerized and expressed in CHO cells. All IND enabling activities including pharmacology, GMP manufacturing, formulation and GLP toxicology studies have been conducted. The IND application has been filed and cleared by the Food and Drug Administration. A first-in-human, first-in-class phase 1 safety and efficacy clinical study of AG01 in patients with solid tumors and advanced disease with special focus on patients with breast, lung and ovarian cancers has been initiated and is on-going at the University of Maryland Greenebaum Cancer Center. The trial is registered as NCT05627960 to clinicaltrials.gov site. The presentation will provide an update on the number of patients enrolled in this on-going phase 1A trial. Supported by grants R44CA162629 and R44CA224718 from the National Cancer Institute to GS. Citation Format: Katherine Tkaczuk, Paula Rosenblatt, Ranee Mehra, Katherine Scilla, Nancy Tait, Binbin Yue, Ginette Serrero. On-going phase 1A clinical trial of A01, a chimerized monoclonal antibody to Progranulin/Glycoprotein 88 (GP88) in patients with advanced malignancy [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 PO5-18-06.

Abstract PO4-06-07: Efficacy and safety of futibatinib in patients with locally advanced/metastatic triple-negative breast cancer harboring FGFR2 gene amplification: final results from the phase 2, open-label FOENIX-MBC2 study

Abstract Background: Triple-negative breast cancer (TNBC) accounts for ~15% of breast cancers and represents an aggressive subtype with limited targeted therapeutic options. Fibroblast growth factor receptor (FGFR) signaling plays an important role in breast tumorigenesis and metastasis. The phase 2 FOENIX-MBC2 study (NCT04024436) was designed to evaluate responses to futibatinib, a highly selective and potent irreversible covalent inhibitor of FGFR1–4 (FDA-approved for intrahepatic cholangiocarcinoma), in patients with metastatic breast cancer. Here, we report final efficacy and safety data for futibatinib in the cohort of patients with advanced/metastatic TNBC harboring FGFR2 gene amplification. Methods: Eligible patients had locally advanced/metastatic TNBC with measurable disease per RECIST v1.1, an ECOG performance status of 0/1, and progressive disease after ≥1 prior chemotherapy-containing regimen for advanced disease. Patients were positive for FGFR2 gene amplification determined by analysis of tumor tissue or circulating tumor DNA. Patients received oral futibatinib 20 mg once daily until disease progression, unacceptable toxicity, or other discontinuation criteria were met. The primary endpoint was objective response rate (ORR) by RECIST v1.1 in patients with centrally confirmed FGFR2 amplification. Responses (complete response and partial response) required confirmation after at least 4 weeks. Secondary endpoints included the 6-month progression-free survival (PFS) rate, PFS, duration of response (DOR), and overall safety. Results: Overall, 21 female patients with TNBC were enrolled (median age: 53 years) in this cohort. Patients had received a median 5 lines of prior systemic therapy. Overall, 2 patients had a confirmed partial response (ORR: 9.5%; 95% confidence interval [CI]: 1.2, 30.4), with a median DOR of 6.1 months (range: 3.1−9.2 months). Five (23.8%) patients had stable disease. PFS at 6 months was observed in 4 patients (19.0%; 95% CI: 5.4, 41.9) and the median PFS was 1.9 months (95% CI: 1.6, 4.0). Twenty patients (95.2%) had ≥1 treatment-related adverse event (TRAE), including 7 (33.3%) with a Grade 3 TRAE (no Grade 4 or 5). Common TRAEs (any grade) included hyperphosphatemia (85.7% of patients), constipation, diarrhea, fatigue, and dry skin (each in 23.8% of patients). Anemia was the only Grade 3 TRAE observed in more than 1 patient (n=2, 9.5%). Overall, 28.6% of patients had a serious adverse event (SAE; any cause), and 1 patient had an SAE leading to death (ischemic stroke). None of the SAEs or deaths were considered treatment-related. Conclusions: In heavily pretreated patients with metastatic TNBC harboring FGFR2 gene amplification, futibatinib monotherapy demonstrated modest anticancer activity. Futibatinib was tolerable and had an acceptable safety profile, consistent with previous data. Further biomarker work to identify patients who might benefit most from futibatinib is ongoing. Clinical trial information: NCT04024436 Citation Format: Antonio Giordano, Nisha Unni, Senthil Damodaran, Hope Rugo, Timothy Crook, Thomas Bachelot, Federico Piacentini, Hector Soto Parra, Ian Krop, Masashi Shimura, Gareth Tomlinson, Maciej Gil, Nicholas Turner, Fabrice André. Efficacy and safety of futibatinib in patients with locally advanced/metastatic triple-negative breast cancer harboring FGFR2 gene amplification: final results from the phase 2, open-label FOENIX-MBC2 study [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 PO4-06-07.

Abstract PO2-05-13: HER2 status presented an unstable switching from primary to recurrent breast cancer

Abstract Background: Breast cancer patients with HER2-2+ expression had heterogeneous characteristic. Treatment decision is of great importance after progression. Objective: We explored patients with HER2-2+ in matched primary or recurrent/metastatic tumor samples from January 2010 to June 2022 in our institute were included to evaluate the evolution from or to HER2-2+ expression. Meanwhile, with an emerging of novel entity as HER2-low expression breast cancer, we included this category when analysis as well. Results: In the cohort of a total of 159 breast cancer patients with HER2-2+ expression in either primary tumor or locoregional/distant metastases samples, HER2-2+ breast cancer accounted for 44.0% in primary tumor and 88.8% in recurrent diseases. There were 18.5% and 15.2% patients with HER2 gene amplification on ISH assay among primary and recurrent/metastatic HER2-2+ breast cancers, respectively. The overall rate of HER2 IHC discordance was 67.1%. Among primary HER2-2+ cases, 74.6% maintained in HER2-2+ when disease relapsed. Discordance was mostly driven by cases switching from HER2-2+ to HER2-1+ (64.7%). In HER2-2+ recurrent/metastatic cases, discordance was mostly driven by cases switching from HER2-0 to HER2-2+ (47.1%). The proportion of HER2 discordant cases got a higher statistically trend among HR-positive patients in compared with HR-negative patients (44.1% vs. 21.7%, p = 0.062). There were 35.0% in primary HR-positive/HER2-negative patients and 11.8% in primary triple-negative patients switching from HER2-0 to HER2-low when disease progressed, respectively. Meanwhile, HER2 discordance rate had a significant difference across different metastatic sites (p = 0.026). All contralateral breast and skin metastasis presented with discordant HER2 results. While, all central nervous system metastasis maintained the same HER2-low expression. HER2-positive phenotype in primary breast cancer samples loss their positivity in 42.1% cases. There was a total of 6.6% cases gained HER2 positivity in recurrent breast cancer samples. Conclusion: HER2 expression from primary to relapse breast cancer samples were highly unstable. Biopsy of recurrent sites was necessary to find novel treatment. Citation Format: Anjie Zhu, Hui-Ping Li. HER2 status presented an unstable switching from primary to recurrent breast cancer [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 PO2-05-13.

Abstract PO1-16-12: The McPeak-Sirois Group Breast Metastases Registry

Abstract Background: In 2020, the McPeak-Sirois Group (MPSG), a Quebec-based breast cancer trials consortium, launched a feasibility pilot project to register prospectively cases of metastatic breast cancer (MBC). This Breast Metastases Registry (BMR) had the following objectives: a) to measure real-world progression-free and overall survival; b) to capture real-world evidence in efficacy of novel therapeutic approaches and c) to facilitate the development of clinical research projects in MBC. Methods: The pilot phase was initiated in three major academic hospitals with the intention of testing the feasibility of building a BMR and to assess barriers before extension to other hospitals in the province of Quebec. Funding was obtained through non-profit organizations and the pharmaceutical industry. The project was approved by a research ethics board and informed consent was obtained from each patient. The main inclusion criteria was a MBC diagnosis at the time of enrolment. Metastatic diseases were considered de novo if the metastatic condition was detected at the same time of the primary disease diagnosis or within the following 4 months. The information in the BMR relates to participants’ health status, including but not limited to hospitalizations, diagnoses, medications, medical procedures and imaging, pathology, genetic and laboratory results. In addition to the prospective data, the registry also captures information retrospective to the date of enrollment. Results: Between July 30, 2021 and April 22, 2023, a total of 427 patients were approached by a research nurse and 423 patients enrolled and 4 refused (99.2% participation rate). Approximately one third of the cohort was diagnosed between 2021-2023 (30.3%) while 69.7% were in 2002-2020 timeframe. The majority was either HR+/HER2- (55.3%) or HER2+ (26.9%). The median age at the time of MBC diagnosis was 57 years (Q1-Q3 range: 47-67 years). We observed that 57.9% of patients had a relapsed MBC while de novo MBC comprised 42.1% of the cohort with the highest percentage in the HER2+ group (59.6%). The median time between primary cancer and metastatic disease in those with relapsed MBC is shorter in triple negative breast cancer (28.9 months) compared to 71.4 months in HR+ disease. Among all lines of treatment for metastatic disease, independently of age at time of MBC diagnosis, 21% of patients participated in a clinical trial. Discussion: The pilot project demonstrated the acceptability and feasibility of building a MBC provincial registry as illustrated by the high participation rate (more than 99%). The next step is to expand the registry to other hospital sites in Quebec, however, the main difficulty is having the necessary manpower (oncology registrars) to ensure data entry. Over one third of the MBC patients presented as de novo disease (and more than half of these with HER2+ disease). This proportion of de novo MBC is unusually high and is likely due to a recruitment bias during the pilot phase as data entry was prioritised for de novo diagnoses over MBC at time of recurrence and patients were recruited at any time in their MBC trajectory and not only at the time of their MBC diagnosis. Clinical trial participation was higher in our cohort compared to the usually reported 5% participation rate. This may be due to recruitment bias but needs to be evaluated further. Conclusion: We have found that recruiting patients in a metastatic cancer registry and collecting their real-world data is not only feasible but well received by patients. The limiting factor for expansion to other hospitals is lack of oncology registrars. At maturity, the BMR will be a unique and powerful resource for breast cancer research and will allow researchers and their collaborators to unite their efforts to better understand how stage IV breast cancer is treated and how management of the disease can be improved. The BMR could also have the potential to improve participation in clinical trials and to stimulate clinical research. Citation Format: Julie Lemieux, Danielle Charpentier, Dominique Johnson, Nathalie Bolduc, Caty Blanchette, Claude Nadon, Sarkis Meterissian. The McPeak-Sirois Group Breast Metastases Registry [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 PO1-16-12.

Mitochondria-Associated Gene SLC25A32 as a Novel Prognostic and Immunotherapy Biomarker: From Pan-Cancer Multiomics Analysis to Breast Cancer Validation

Background. Mutations in SLC25A32 in humans cause late-onset exercise intolerance, which is associated with various neurological and metabolic diseases. However, its specific mechanism of action in tumour development is poorly understood owing to the lack of multiomics integrated analysis of SLC25A32 in pan-cancer. Methods. We used various analytical tools to comprehensively investigate the transcription, protein level, and promoter methylation of SLC25A32. Furthermore, the GSCA and cBioPortal databases were used to evaluate the inheritance impact and epigenetic alterations of SLC25A32 in pan-cancer. SLC25A32 expression and the prognostic significance of copy number alterations in multiple cancers were compared using the UCSCXenaShiny and GEPIA2.0 platforms, and its specific function in breast cancer was experimentally verified. Results. SLC25A32 is abnormally expressed at the transcriptional and protein levels in most cancer types, with aberrant DNA promoter methylation and significant gene amplification in most tumours. SLC25A32 is significantly associated with the survival prognosis of some cancers, immune infiltrating cells, tumour stemness, and immune-related markers. SLC25A32 knockdown decreased breast tumour cell proliferation, invasion, and metastasis. Conclusions. This study aimed to reveal SLC25A32 as a novel prognostic biomarker for pan-cancer prediction and immunotherapy efficacy and specifically describes its underlying mechanism of action in breast cancer. SLC25A32 is widely differentially expressed in pan-cancer with prognostic significance and is correlated with immune infiltration. Additionally, it can affect breast cancer occurrence and development.

Exploring the multifaceted bioactivities of Lavandula pinnata L. essential oil: promising pharmacological activities.

Introduction: This study investigates the biological activities of Lavandula pinnata essential oil (LPEO), an endemic lavender species from the Canary Islands, traditionally used in treating various ailments. Methods: LPEO was extracted by hydrodistillation and analyzed using GC-MS. Antioxidant activity was assessed by DPPH radical scavenging and total antioxidant capacity assays. Antimicrobial activity was evaluated by disc diffusion, MIC, MBC, and MFC determination against bacterial (Staphylococcus aureus, Micrococcus luteus, Escherichia coli, Pseudomonas aeruginosa) and fungal (Candida glabrata, Rhodotorula glutinis, Aspergillus niger, Penicillium digitatum) strains. Antidiabetic and anti-gout potential were investigated through α-amylase, α-glucosidase, and xanthine oxidase inhibition assays. Antityrosinase activity was determined using a modified dopachrome method. Cytotoxicity was assessed by MTT assay against breast (MCF-7, MDA-MB-468), liver (HepG2), colon (HCT-15) cancer cells, and normal cells (PBMCs). Results and discussion: LPEO exhibits potent antiradical activity (IC50 = 148.33 ± 2.48μg/mL) and significant antioxidant capacity (TAC = 171.56 ± 2.34μg AA/mg of EO). It demonstrates notable antibacterial activity against four strains (Staphylococcus aureus, Micrococcus luteus, Escherichia coli, and Pseudomonas aeruginosa) with inhibition zones ranging from 18.70 ± 0.30mm to 29.20 ± 0.30mm, along with relatively low MIC and MBC values. LPEO displays significant antifungal activity against four strains (Candida glabrata, Rhodotorula glutinis, Aspergillus niger, and Penicillium digitatum) with a fungicidal effect at 1mg/mL, surpassing the positive control (cycloheximide), and MIC and MFC values indicating a fungicidal effect. It exhibits substantial inhibition of xanthine oxidase enzyme (IC50 = 26.48 ± 0.90μg/mL), comparable to allopurinol, and marked inhibitory effects on α-amylase (IC50 = 31.56 ± 0.46μg/mL) and α-glucosidase (IC50 = 58.47 ± 2.35μg/mL) enzymes.The enzyme tyrosinase is inhibited by LPEO (IC50 = 29.11 ± 0.08mg/mL). LPEO displays moderate cytotoxic activity against breast, liver, and colon cancer cells, with low toxicity towards normal cells (PBMC). LPEO exhibits greater selectivity than cisplatin for breast (MCF-7) and colon (HCT-15) cancer cells but lower selectivity for liver (HepG2) and metastatic breast (MDA-MB-468) cancer cells. These findings suggest the potential of LPEO as an antioxidant, antimicrobial, anti-gout, antidiabetic, and anticancer agent.

Abstract LB446: Decoding the mechanism of metastasis: A novel CAF-therapy that blocks the tumor microenvironment and reverses metastatic traits in all solid tumors

Abstract Progression and metastatic spreading of cancer cells are modulated by the carcinoma-associated fibroblasts (CAFs) within the primary tumor microenvironment in solid tumors. However, the mechanisms through which CAFs exert their pro-metastatic effects on cancer cells remain unknown. In this study, we have developed a small molecule that blocks Neuropilin-1 signaling in metastatic CAFs (mCAFs), reversing the mechanisms that promote metastasis in prostate, breast, colorectal and pancreatic cancer. To address these critical needs, in this study, we sought to assess the potential role of proteoglican neuropilin 1 (PG-NRP1) signaling in the maintenance of the activated CAF phenotype. Our results by gene expression profile, qPCR, WB, and ELISA indicate that CAFs isolated from primary tumors of metastatic patients (mCAFs) are functionally different from CAFs isolated from primary tumors of non-metastatic patients, promoting metastasis traits of cancer cells. Among the most prominent differences is an increased PG-NRP1 expression. siRNA studies demonstrated that the knockdown of NRP-1 in mCAFs showed the reversion of the activated phenotype, evaluated by the activation markers a-SMA, Tenascin C, and Fibronectin. Furthermore, conditioned media from PG-NRP1-siRNA-mCAFs failed to increase cancer cells' metastasis traits (migration and invasion) in vitro and tumor progression in vivo. Furthermore, we engineered a small molecule designed to bind PG-NRP1 in mCAFs. Our findings, demonstrate in vitro and in vivo models that the inhibition of PG-NRP1 impedes tumor growth and metastatic dissemination of cancer cells in spontaneous metastasis assay. We designed and validated, using in vivo models, an inhibitor that blocks NRP1-mCAF. Our research demonstrates that blocking PG-NRP1 in mCAF, with a small molecule, is a transversal therapeutic strategy to prevent progression and metastatic spread in solid cancer tumors. Citation Format: Benjamin Prieto, Muriel Núñez, Valentina I. Cerdfa, Javier Cerda-Infante. Decoding the mechanism of metastasis: A novel CAF-therapy that blocks the tumor microenvironment and reverses metastatic traits in all solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB446.

Activation of the YY1-UGT2B7 Axis Promotes Mammary Estrogen Homeostasis Dysregulation and Exacerbates Breast Tumor Metastasis.

Metastasis is the most common pathway of cancer death. The lack of effective predictors of breast cancer metastasis is a pressing issue in clinical practice. Therefore, exploring the mechanism of breast cancer metastasis to uncover reliable predictors is very important for the clinical treatment of breast cancer patients. In this study, tandem mass tag quantitative proteomics technology was used to detect protein content in primary breast tumor tissue samples from patients with metastatic and nonmetastatic breast cancer at diagnosis. We found that the high expression of yin-yang 1(YY1) is strongly associated with poor prognosis in high-grade breast cancer. YY1 expression was detected in both clinical tumor tissue samples and tumor tissue samples from mammary-specific polyomavirus middle T antigen overexpression mouse model mice. We demonstrated that upregulation of YY1 expression was closely associated with breast cancer metastasis and that high YY1 expression could promote the migratory invasive ability of breast cancer cells. Mechanistically, YY1 directly binds to the UGT2B7 mRNA initiation sequence ATTCAT, thereby transcriptionally regulating the inhibition of UGT2B7 expression. UGT2B7 can regulate the development of breast cancer by regulating estrogen homeostasis in the breast, and the abnormal accumulation of estrogen, especially 4-OHE2, promotes the migration and invasion of breast cancer cells, ultimately causing the development of breast cancer metastasis. In conclusion, YY1 can regulate the UGT2B7-estrogen metabolic axis and induce disturbances in estrogen metabolism in breast tumors, ultimately leading to breast cancer metastasis. Disturbances in estrogen metabolism in the breast tissue may be an important risk factor for breast tumor progression and metastasis SIGNIFICANCE STATEMENT: In this study, we propose for the first time a regulatory relationship between YY1 and the UGT2B7/estrogen metabolism axis and explore the molecular mechanism. Our study shows that the YY1/UGT2B7/estrogen axis plays an important role in the development and metastasis of breast cancer. This study further elucidates the potential mechanisms of YY1-mediated breast cancer metastasis and the possibility and promise of YY1 as a predictor of cancer metastasis.

B7-H3 Expression in Breast Cancer and Brain Metastasis.

Brain metastasis is a significant challenge for some breast cancer patients, marked by its aggressive nature, limited treatment options, and poor clinical outcomes. Immunotherapies have emerged as a promising avenue for brain metastasis treatment. B7-H3 (CD276) is an immune checkpoint molecule involved in T cell suppression, which is associated with poor survival in cancer patients. Given the increasing number of clinical trials using B7-H3 targeting CAR T cell therapies, we examined B7-H3 expression across breast cancer subtypes and in breast cancer brain metastases to assess its potential as an interventional target. B7-H3 expression was investigated using immunohistochemistry on tissue microarrays of three clinical cohorts: (i) unselected primary breast cancers (n = 347); (ii) brain metastatic breast cancers (n = 61) and breast cancer brain metastases (n = 80, including a subset of 53 patient-matched breast and brain metastasis cases); and (iii) mixed brain metastases from a range of primary tumours (n = 137). In primary breast cancers, B7-H3 expression significantly correlated with higher tumour grades and aggressive breast cancer subtypes, as well as poorer 5-year survival outcomes. Subcellular localisation of B7-H3 impacted breast cancer-specific survival, with cytoplasmic staining also correlating with a poorer outcome. Its expression was frequently detected in brain metastases from breast cancers, with up to 90% expressing B7-H3. However, not all brain metastases showed high levels of expression, with those from colorectal and renal tumours showing a low frequency of B7-H3 expression (0/14 and 2/16, respectively). The prevalence of B7-H3 expression in breast cancers and breast cancer brain metastases indicates potential opportunities for B7-H3 targeted therapies in breast cancer management.

The trend of dental check-up and prevalence of dental complications following the use of bone modifying agents in patients with metastatic breast and prostate cancer: analysis of data from the Korean National Health Insurance Service

BackgroundBone-modifying agents (BMA) are key components in the management of cancer patients with bone metastasis. Despite their clinical benefits, the use of BMA is associated with dental adverse events (AEs) including medication-related osteonecrosis of the jaw (MRONJ). This study investigated the frequency of dental surveillance before BMA treatment and the prevalence of dental AEs including MRONJ, after BMA treatment in patients with bone metastasis from breast and prostate cancer using data from the national health insurance system.MethodsData, including age, cancer diagnosis, administered BMA, and dental AEs during cancer treatment, of patients with bone metastasis from breast and prostate cancer who received at least one infusion of BMA between 2007 and 2019 were extracted from the Korean National Health Insurance Service (KNHIS) dataset.ResultsOf the 15,357 patients who received BMA, 1,706 patients (11.1%) underwent dental check-ups before BMA treatment. The proportion of patients receiving dental check-up increased from 4.4% in 2007 to 16.7% in 2019. Referral to dentists for a dental check-up was more active in clinics/primary hospitals than general/tertiary hospitals, and medical doctors and urologists actively consulted to dentists than general surgeons, regardless of the patient’s health insurance status. After BMA treatment, 508 patients (3.8%) developed dental AEs, including abscess (42.9%), acute periodontitis (29.7%), acute pericoronitis (14.9%), and MRONJ (12.5% of dental AEs cases, 0.5% of total BMA treated patients).ConclusionsConsidering the long treatment period in patients with metastatic cancer, coordination between dentists and oncologists is necessary to ensure appropriate dental management before the initiation of BMA.

495 Optimizing Drug Delivery to the Brain for Breast Metastasis: A Novel Method for Tumor Targeting

INTRODUCTION: Brain metastases are difficult to treat due to the blood-brain barrier limiting delivery of therapeutic agents to the brain effectively. Intraventricular drug delivery has not been well studied for intra-axial pathologies. However, our prior work demonstrated that intraventricular drug delivery in a hyperosmolar vehicle showed preferential accumulation of drug within breast cancer tissue compared to surrounding brain parenchyma. METHODS: We used an intracerebral breast cancer tumor model in adult female nude rats divided into six experimental groups. We examined three iron labeled dextran molecules (3 KD, 5KD, and 10 KD) in 337 mOsm/L solution and three different osmolarities of delivery solution (307, 353, 368 mOsm/L) with 10 KD dextran. 7T MR imaging was used to analyze dextran distribution at different time points. All animals were sacrificed after 2 hours and quantity of dextran particles was determined by histopathology. RESULTS: Breast cancer tumor cells were successfully implanted in all rats. MRI quantification of dextran concentration was well corroborated by histopathology. Varying the molecular size of dextran resulted in the smallest molecule reaching peak levels in tumor tissue earlier than the larger molecules but the larger molecules remained concentrated in tumor tissue for a longer time. Varying the osmolarity of the delivery solution resulted in preferential accumulation of 10 KD dextran in tumor tissue except for when dextran was delivered in 368 mOsm/L solution where no preferential distribution was seen. CONCLUSIONS: Hyperosmolar intraventricular delivery of chemotherapeutic drugs could be effective in preferentially delivering drugs to abnormal tumor tissues.

Higher Serum IL-8 is associated with Reduced PFS and OS during Systemic Therapy in Metastatic Breast, Pancreatic and Prostate Cancer: A Retrospective Study in Patients from BOLERO-2 Trial, Pancreatic and Prostate Cancer Cohorts

Higher Serum IL-8 is associated with Reduced PFS and OS during Systemic Therapy in Metastatic Breast, Pancreatic and Prostate Cancer: A Retrospective Study in Patients from BOLERO-2 Trial, Pancreatic and Prostate Cancer Cohorts

Metastasis of serous ovarian carcinoma to the breast: a case report and review of the literature

BackgroundBreast metastasis from primary ovarian cancer is rare, with an estimated frequency of 0.07%. More than 110 cases are reported in the literature of metastatic spread of ovarian cancer to the breast and axilla. This entity usually represents aggressive late disease characterized by multi-drug chemoresistance and a poor prognosis with a median survival time of 16 months. Currently no standardized treatment protocol exists for this condition.Case presentationWe present a case of a 59-year-old Caucasian female with recurrent high-grade serous ovarian cancer who was diagnosed with symptomatic unilateral breast metastasis while on fourth line chemotherapy with weekly paclitaxel. She was treated with local radiation with 2300 cGy to the right breast with a complete response. She then had a subsequent recurrence in the ipsilateral breast 8 months after completion of post treatment imaging. She remains alive to date approximately 2 years after her initial diagnosis of breast metastasis on seventh line treatment.ConclusionsBreast metastasis from primary ovarian cancer is rare and represents advanced disease characterized by multi-drug chemoresistance and a poor prognosis. This case describes radiation therapy as a safe, effective treatment option to improve local control and quality of life in these patients, but with limited durability of response.

Abstract 4486: Characterization of a novel mutant selective, EGFR sparing, ErbB2 inhibitor with activity across activating mutations in systemic and CNS tumors

Abstract Alterations in ErbB2, including amplification, overexpression, insertions, and point mutations, are established oncogenic drivers in many solid tumors. These mutations are found in approximately 3-4% of breast cancers and 3% of advanced lung cancers and have emerged as mechanisms of acquired resistance to targeted therapies. ErbB2 alterations are also found in metastatic breast and lung cancers that have advanced to the brain and remain a major clinical challenge with limited therapeutic options. Currently approved ErbB2 tyrosine kinase inhibitors have inferior potency against these mutations and lack sufficient brain penetration to be an impactful treatment option for patients. Herein, we describe advanced preclinical profiling of our candidate series of brain-penetrant EGFR-sparing ErbB2 inhibitors with activity against prevalent point mutations and exon 20 YVMA insertions. Citation Format: Jennifer Fulton, Tanna Bettendorf, Abiezer Blandon, Karyn Bouhana, Richard K. Brizendine, LouAnn Cable, Mark J. Chicarelli, Michelle Crow, Brad Fell, John Fischer, Anna Guarnieri, Madison Hillman, Ravi Jalluri, Vijay Kumar, Cori A. Malinky, Rob Rieger, John Robinson, Lee Stunkard, Francis Sullivan, John I. Trujillo, Shannon Winski, Yeyun Zhou. Characterization of a novel mutant selective, EGFR sparing, ErbB2 inhibitor with activity across activating mutations in systemic and CNS tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4486.

Abstract 7492: Automated identification and enumeration of CELLSEARCH Circulating Tumor Cells (CTC) with a deep learning algorithm

Abstract Introduction: CTC enumeration in blood samples with CELLSEARCH® is a prognostic biomarker in metastatic breast, prostate and colorectal cancer (full intended use documents.cellsearchctc.com). Currently, CTC identification is performed by visual assessment, which is time-consuming and potentially affected by subjective interpretations. Recently, we developed a Deep Learning (DL) algorithm for automated CTC identification in CELLSEARCH images (CellFind®, Menarini Silicon Biosystems, research use only). This study aims to assess the CTC identification performance of CellFind on 2 different datasets: the first for comparison with human reviewers, and the second for validation with much higher number of images. Methods: CellFind is composed of an image segmentation followed by a classification network, which was trained using 13067 CTC and 52890 non-CTC images from 215 breast, 123 prostate and 180 colorectal cancer samples. The performance of CellFind was tested on 2 separate datasets. 1) The first dataset was made of CELLSEARCH gallery images from 26 breast cancer, 68 prostate cancer, and 40 benign samples. 8 human reviewers, qualified for CTC image analysis, performed blind labeling. The Ground Truth (GT) was generated by the classification of the 3 most experienced reviewers by majority voting (1621 CTCs out of 17080 images). Accuracy and F1 metrics were used to rank the performance of DL and 5 reviewers against the GT. 2) The second dataset was made of CELLSEARCH gallery images from 63 breast, 66 prostate and 32 colorectal cancer samples. 3 experienced reviewers created the GT classification by majority voting, identifying 20052 CTCs out of 117447 images.Finally, each patient was assigned to the favorable or unfavorable group by applying the validated cutoff on CTC enumeration per sample (CTC≥5 for breast and prostate cancer, CTC≥3 for colorectal cancer). Results: 1) On 17080 gallery images from 134 samples, CellFind reached top human-level performance, as ranked both by accuracy (97.8% for DL vs. 96.8-98.0%) and F1 (88.6% for DL vs. 83.3-89.9% for reviewers). On the 94 cancer samples, DL accuracy on favorable/unfavorable prognosis was 98.9% vs. 95.8-97.9% for reviewers. 2) On the bigger dataset with 117447 gallery images from 161 cancer samples, CellFind obtained accuracy = 96.0% and F1 = 87.8% for CTC identification (TP = 17039, FP = 1735, FN = 3013, TN = 95660). For favorable/unfavorable prognosis the DL accuracy was 95.4%. Conclusion: Automated identification and enumeration of CTCs in CELLSEARCH images with CellFind can remove human subjectivity from the review process and maximize standardization among different research centers. CellFind performed better than most operators and reduced the data processing time required for each blood sample by the operator. Citation Format: Luca Biasiolli, Pietro Ansaloni, Nicolò Gentili, Daniele Giardiello, Francesco Montanari, Ramona Miserendino, Giulio Signorini, Gianni Medoro. Automated identification and enumeration of CELLSEARCH Circulating Tumor Cells (CTC) with a deep learning algorithm [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7492.

Abstract 6630: Non-cell-autonomous cancer progression from chromosomal instability

Abstract Chromosomal instability (CIN) is a driver of cancer metastasis, yet the extent to which this effect depends on the immune system remains unknown. Using ContactTracing—a newly developed, validated and benchmarked tool to infer the nature and conditional dependence of cell-cell interactions from single-cell transcriptomic data—we show that CIN-induced chronic activation of the cGAS-STING pathway promotes downstream signal re-wiring in cancer cells, leading to a pro-metastatic tumor microenvironment. This re-wiring is manifested by type I interferon tachyphylaxis selectively downstream of STING and a corresponding increase in cancer cell-derived endoplasmic reticulum (ER) stress response. Reversal of CIN, depletion of cancer cell STING or inhibition of ER stress response signaling abrogates CIN-dependent effects on the tumor microenvironment and suppresses metastasis in immune competent, but not severely immune compromised, settings. Treatment with STING inhibitors reduces CIN-driven metastasis in melanoma, breast and colorectal cancers in a manner dependent on tumor cell-intrinsic STING. Finally, we show that CIN and pervasive cGAS activation in micronuclei are associated with ER stress signaling, immune suppression and metastasis in human triple-negative breast cancer, highlighting a viable strategy to identify and therapeutically intervene in tumors spurred by CIN-induced inflammation. Citation Format: Jun Li, Melissa Hubisz, Ethan Earlie, Mercedes Duran, Christy Hong, Austin Varela, Emanuele Lettera, Matthew Deyell, Bernardo Tavora, Jonathan Havel, Phyu Su, Amit Dipak Amin, Karolina Budre, Erina Kamiya, Julie-Ann Cavallo, Christopher Garris, Simon Powell, Jorge Reis-Filho, Hannah Wen, Sarah Bettigole, Atif Khan, Benjamin Izar, Eileen Parkes, Ashley Laughney, Samuel Bakhoum. Non-cell-autonomous cancer progression from chromosomal instability [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6630.

Abstract 5963: VGLL1-derived peptides demonstrated anticancer effect by inhibiting VGLL1-TEAD4 interaction

Abstract YAP/TAZ, cofactors of TEA domain-containing transcription factor TEADs (TEAD1-4), play a key role in the HIPPO pathway, which is involved in various function including embryonic development, organ size, cell proliferation, tissue regeneration, and the development and progression of several cancers. YAP/TAZ is therefore considered as master regulators of various cancers. However, we are interested in VGLL1, a cofactor of TEAD4, because it is mainly involved in the proliferation and metastasis of various cancers, including gastric, breast, pancreatic, and ovarian cancers. In gastric cancer, VGLL1 expression is regulated by the PI3K/AKT/β-catenin pathway. VGLL1 is then phosphorylated at S84 by TGF-β/ribosomal S6 kinase 2 (RSK2) and interacts with TEAD4 to express target genes such as MMP9, cyclin D1, IGFBP3, IGFBP5 and ITGαV. which are involved in cancer malignancy. We designed S84-containing VGLL1-derived peptides (VGLL1S84 peptides, SCVP), which consist of 7 to 15 amino acids linked to CPP, a cell-penetration peptide. We evaluated SCVP to inhibit the VGLL1-TEAD4 interaction and their therapeutic potential as anticancer agents. SCVP suppressed the growth of gastric and breast cancer cells expressing high levels of VGLL1, EGFR, and/or HER2. In the RNA-seq analysis of NUGC3 to elucidate the molecular mechanisms of SCVP induced cell death, SCVP-treated cells showed gene expression changes in metabolic pathway, RAS signaling, PI3K-AKT signaling, Wnt signaling, TNF signaling, and mTOR signaling. However, RNA-seq analysis of breast cancer cells treated with SCVP showed changes in the expression of genes involved in cell cycle, DNA replication, DNA repair, and apoptosis. Then, we performed CRISPR/Cas9 screening using SCVP and sgRNA library to explore companion biomarkers and genetic interactors of VGLL1 for targeted cancer therapy. As a result, we identified several candidate genes, including ZNF292 and PLK1, as synthetic lethal genes of VGLL1. As expected, HCC70 cells with ZNF292 mutation showed increased sensitivity to SCVP. We also found that SCVP in combination and the PLK inhibitor volasertib resulted in a synergistic effect on the growth inhibition of breast cancer cells. In conclusion, we demonstrated VGLL1 as a novel target for anticancer drug development, and elucidated the molecular mechanism and therapeutic potential of the SCVP in gastric and breast cancers. Citation Format: Sangmi Ock, Changsub Lee, Wongi Jung, Ina Whang, Kyung-Soo Kim, Jongmin Han, Sujin Yim, Bo-Kyung Kim, Hong-Sub Lee, Kwan-Young Chang, Misun Won. VGLL1-derived peptides demonstrated anticancer effect by inhibiting VGLL1-TEAD4 interaction [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5963.