Development Of Brain Metastases Research Articles

Abstract PO5-16-10: The efficacy of novel antibody-drug-conjugates on brain metastases in metastatic breast cancer patients – a multicenter real-world analysis

Abstract 15 – 30% of all patients with metastatic breast cancer (MBC) develop brain metastases (BMs). Treatment of BMs include radiation therapy and surgical resection while systemic treatment is challenging and prospective evidence for the treatment of active brain metastases is restricted to the small molecule Tucatinib. Recently, the antibody-drug-conjugates (ADCs) Sacituzumab-Govitecan (SG) and Trastuzumab-Deruxtecan (T-DXd) have shown to be highly effective in the treatment of triple-negative (SG), HER2-positive (T-DXd) and HR+/HER2- (SG and, in case of HER2-low-expression, T-DxD) MBC. However, there is only limited data, whether these macromolecules are also effective in patients with BMs. We therefore aimed to examine the efficacy of SG and T-DXd in patients with stable and active BMs in a multicenter real-world analysis. Female patients with stable or active BMs who were treated with either SG or T-DXd at the breast centers of Tuebingen University, Ulm University or Freiburg University in Germany before June 30, 2023 were included into this analysis. Data cut-off for this analysis was July 10, 2023. BMs were classified as active if they were newly diagnosed and did not require local treatment or if they were progressing and did not require local treatment. Preexisting BMs without intracranial disease progression or preexisting/newly diagnosed BMs that had been treated by surgery and/or radiotherapy directly prior to SG/T-DXd therapy were considered as stable. All patients underwent baseline magnetic resonance imaging (MRI) of the brain and received follow-up MRIs at least every three months. Growth dynamics of BMs were assessed by board certified neuroradiologists. Intracranial disease control rate (icDCR) was defined as the percentage of patients with at least intracranial stable disease at the first follow-up MRI. Intracranial progression-free survival (icPFS) was determined as the period between the first application of SG or T-DXd and intracranial disease progression or treatment cessation due to the patients’ will or the onset of intolerable toxicity. If ADC treatment was discontinued due to extracranial disease progression albeit at least stable intracranial disease patients were censored. Overall survival (OS) was defined as the period between the first application of SG or T-DXd and death. In total, 26 patients were included with a median of two prior therapy lines in the metastatic setting (range 2 – 15). 10 (38%) and 14 (54%) patients received SG and T-DXd, respectively. 2/26 (8%) patients receiving SG were consecutively subjected to T-DXd treatment. SG was applied to 12/12 patients (100%) due to triple-negative MBC and 12/16 patients (75%) treated with T-DXd were HER2-positive. The remaining 4/16 patients (25%) treated with T-DXd showed HER2 low tumor biology. 5/12 (42%) and 8/16 (50%) patients treated with SG or T-DXd had active BMs at treatment initiation. The icDCR was 33% (95% CI: 5% - 61%)/81% (95% CI: 62% - 100%) for all patients treated with SG/T-DXd and 40% (95% CI: 0% - 88%)/75% (95% CI: 43% - 100%) in case of active BMs. After a median follow-up of 7.2 months, 10/12 (83.3%) patients treated with SG and 4/16 (25%) patients subjected to T-DXd had discontinued treatment. Median icPFS was 3.1 months (95% CI: 0.4 – 5.8 months) for SG and not reached for T-DXd. 7/12 (58%) patients treated with SG and 4/16 patients (25%) treated with T-DXd died until data cut-off. Median OS was 7.2 months (95% CI: 3.0 – 11.4 months) for patients treated with SG and not reached for patients treated with T-DXd. SG and T-DXd showed promising clinical activity in both, stable and active cerebral breast cancer metastasis. Updated PFS and OS data will be reported at the meeting. Citation Format: Dominik Dannehl, Henning Schäffler, Tobias Engler, Lea Volmer, Arne Estler, Ilinca Popp, Stefanie Lorenz, Eva-Maria Grischke, Markus Hahn, Ghazaleh Tabatabai, Ingolf Juhasz-Böss, Wolfgang Janni, Sara Brucker, Florin-Andrei Taran, Andreas Hartkopf. The efficacy of novel antibody-drug-conjugates on brain metastases in metastatic breast cancer patients – a multicenter real-world analysis [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 PO5-16-10.

Abstract PO5-20-02: Secondary BRain metastases prevention after Isolated intracranial progression on trastuzumab/pertuzumab or T-DM1 in pts with aDvanced human epidermal Growth factor receptor 2+ brEast cancer with addition of Tucatinib (BRIDGET)

Abstract Background: Despite treatment with trastuzumab-based therapy, up to half of patients with HER2+ advanced/metastatic breast cancer (MBC) will develop brain metastases (BrM). First-line therapy for advanced HER2+ MBC remains a taxane, trastuzumab, pertuzumab (TP) which demonstrates poor brain permeability. Isolated brain relapse with stable or absent extracranial disease remains a clinical problem in both the adjuvant (Untch et al., ESMO 2019 Congress) and metastatic settings (Noteware et al., Breast Cancer Res Treat. 2023). Current guidelines recommend continuing current systemic therapy in the setting of first isolated brain relapse following local therapy. Tucatinib, a brain-penetrable HER2-targeting tyrosine kinase inhibitor, when added to trastuzumab and capecitabine improves intracranial progression free survival (PFS) and overall survival (OS) in patients with stable or active HER2+ BrMs. We hypothesize that adding tucatinib to TP or T-DM1 in patients with HER2+ MBC with isolated brain relapse or progression could delay or prevent the development of further intracranial lesions and improve OS. Methods: BRIDGET (NCT05323955) is a single arm, phase II, multicenter study of tucatinib added to TP or T-DM1 after local therapy in patients with isolated brain relapse or progression. A total of 48 patients at 9 U.S. sites as part of the Hoosier Cancer Research Network (HCRN) with metastatic HER2+ breast cancer will be enrolled after 1st or 2nd BrM relapse or progression within 8 weeks of local therapy. Patients must currently be receiving standard of care treatment with TP or T-DM1 in the metastatic setting, or adjuvant trastuzumab-based or T-DM1 therapy with isolated brain recurrence. Extracranial disease must be stable per RECISTv1.1 or absent. Patients may not have leptomeningeal disease or untreated brain lesions over 5 mm. Patients will receive continuous tucatinib added to their current therapy (TP or T-DM1). The primary objective is intracranial PFS compared to a historical control (H0: PFS < 5 months (mos), HA: PFS > 8 mos) of the HER2CLIMB clinical trial where patients could continue on trial with isolated brain progression. In these patients, median time from brain progression to second progression or death was 7.6 mos (95% CI, 3.9 to 11.3 mos) in the tucatinib arm versus 3.1 mos (95% CI, 1.2 to 4.1 mos) in the control arm (Lin et al., J Clin Onc 2020). Secondary endpoints include PFS by RECISTv1.1, PFS of extracranial disease, locally treated versus new distant intracranial metastasis PFS, site of first progression (brain versus non-brain), OS, and toxicity in patients with BrM. Collection of correlative specimens including archival tissue, cerebrospinal fluid (optional), whole blood for ctDNA are planned. Patient-reported outcomes surveyed utilizing the FACT-BR and FACIT-Fatigue questionnaires are also included for future analyses. As of 7/06/23, accrual is 5 patients of the anticipated 48 patients overall, across 5 sites (Duke University, Dana Farber Cancer Institute, Ohio State University, Providence Portland Medical Center, and Washington University in St. Louis) currently open. An additional 4 sites are pending opening. Those interested in this trial can reach out to the study Principal Investigators, Carey Anders, MD (carey.anders@duke.edu) or Sarah Sammons, MD (sarahl_sammons@dfci.harvard.edu). Citation Format: Sarah Sammons, Amanda Van Swearingen, Laura Noteware, Nusayba Bagegni, Kelly Moulton, Stevie Threatt, Denise Jaggers, Shannon Shea, Eric Lipp, Erin Riley, Sin-Ho Jung, Gloria Broadwater, Masey Ross, Kimberly Strickland, Sasha Beyer, Alison Conlin, Aki Morikawa, Rashmi Murthy, Carey Anders. Secondary BRain metastases prevention after Isolated intracranial progression on trastuzumab/pertuzumab or T-DM1 in pts with aDvanced human epidermal Growth factor receptor 2+ brEast cancer with addition of Tucatinib (BRIDGET) [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 PO5-20-02.

Incidence and outcome of brain and/or leptomeningeal metastases in HER2-low metastatic breast cancer in the French ESME cohort

Breast cancer (BC) is the second most common cancer that metastasizes to the brain. Particularly up to half of patients with human epidermal growth factor receptor 2 (HER2)-positive (HER2+) metastatic breast cancer (mBC) may develop brain metastases over the course of the disease. Nevertheless, little is known about the prevalence and the outcome of brain and leptomeningeal metastases (BLMM) in HER2-low BC. We compared the cumulative incidence of BLMM and associated outcomes among patients with HER2-low, HER2-negative (HER2-) and HER2+ mBC. This cohort study was conducted from the Epidemiological Strategy and Medical Economics (ESME) mBC database and included patients treated for mBC between 2012 and 2020 across 18 French comprehensive cancer centers and with known HER2 and hormone receptor (HR) status. The cumulative incidence of BLMM after metastatic diagnosis was estimated using a competing risk methodology with death defined as a competing event. 19 585 patients were included with 6118 (31.2%), 9943 (50.8%) and 3524 (18.0%) being HER2-low, HER2- and HER2+ mBC, respectively. After a median follow-up of 48.6 months [95% confidence interval (CI) 47.7-49.3 months], BLMM were reported in 4727 patients: 1192 (25.2%) were diagnosed with BLMM at first metastatic diagnosis and 3535 (74.8%) after metastatic diagnosis. Multivariable analysis adjusted for age, histological grade, metastases-free interval and HR status showed that the risk of BLMM at metastatic diagnosis was similar in patients with HER2- compared to HER2-low mBC [odds ratio (OR) (95% CI) 1.00 (0.86-1.17)] and higher in those with HER2+ compared to HER2-low [OR (95% CI) 2.23 (1.87-2.66)]. Similar results were found after metastatic diagnosis; the risk of BLMM was similar in HER2- compared to HER2-low [subdistribution hazard ratio (sHR) (95% CI) 1.07 (0.98-1.16)] and higher in the HER2+ group [sHR (95% CI) 1.56 (1.41-1.73)]. The prevalence and evolution of BLMM in HER2-low mBC are similar to those in patients with HER2- tumors. In contrast to patients with HER2+ mBC, the prognosis of BLMM remains dismal in this population.

Effectiveness and Safety of Pyrotinib-Based Therapy in the Treatment of HER2-Positive Breast Cancer Patients with Brain Metastases: A Multicenter Real-World Study

BackgroundApproximately 30% to 50% of patients with human epidermal growth factor receptor 2-positive metastatic breast cancer develop brain metastasis (BMs). Pyrotinib has shown promising efficacy in these patients. However, real-world evidence supporting its use is scarce. Therefore, we evaluate the efficacy and safety of pyrotinib-based regimens in the real world. Materials and MethodsWe enrolled patients with BMs from various healthcare facilities in China's Shandong region and used an updated breast-graded prognostic assessment (breast-GPA) to predict survival outcomes. ResultsEfficacy and toxicity were assessed in 101 patients. Overall, the median progression-free survival (PFS) was 11.0 months (95% CI, 7.6-14.4 months). PFS was shorter in patients with a breast-GPA of 0 to 2.0 (P< .001). Previous treatment with pertuzumab plus trastuzumab (P = .039) and varying numbers of BMs (P = .028) had a significant positive correlation with PFS. Additionally, radiotherapy (P = .033) for BMs, especially pyrotinib concurrent with radiotherapy (P = .013), significantly prolonged the PFS. In patients with a breast-GPA of 0 to 2.0, a significant difference in PFS was observed depending on whether the brain was the first metastatic site (P< .001). Furthermore, a breast-GPA (0-2.0 vs. 2.5-4.0), and radiotherapy for BMs were found to be independent predictors of PFS. Overall, the objective response rate was 42.6%, while the disease control rate was 88.1%. Diarrhea emerged as the most common adverse event. ConclusionPyrotinib-based therapy is effective and tolerable in human epidermal growth factor receptor 2-positive metastatic breast cancer with BMs. Patients who underwent radiotherapy for BMs, particularly those who received pyrotinib concurrently with radiotherapy, exhibited a more favorable prognosis.

Abstract CT289: A phase II study of Tucatinib and Ado-trastuzumab Emtansine (T-DM1) in patients with HER2-positive metastatic solid tumors and metastases to brain (TUCATEMEB)

Abstract Background: HER2 overexpression or amplification is a validated prognostic and predictive biomarker for treatments in several tumor types. The development of brain metastases is an unfortunate and common complication in patients with metastatic cancer and the incidence of brain metastases continues to grow as advances in cancer treatment extend the survival. Unfortunately many of the clinical trials still exclude patients with brain metastases. Tucatinib is a selective small molecule HER2 inibitor that has shown intracranial activity and it is approved with trastuzumab and capecitabine for treatment of patients with breast cancer including with active brain metastases. Tucatinib showed significant preclinical and clinical antitumor activity in combination with other HER2-targeted therapies, including T-DM1 in breast and other cancers. We hypothesize that the combination of tucatinib and T-DM1 will be a safe and effective treatment in HER2-positive (+) metastatic solid tumors that have metastasized to the brain. To test this hypothesis, we are conducting a Phase II Study of Tucatinib and T-DM1 in Patients with HER2+ Metastatic Solid Tumors and Metastases to Brain (TUCATEMEB). Methods: Eligible adult patients with HER2-positive solid tumors and active brain metastases (with at least one untreated brain lesion ≥0.5 cm and &amp;lt;3.0 cm) will be enrolled in the study. HER2 positivity is defined as HER2 overexpression by immunohistochemistry 3+ or 2+ and fluorescence in situ hybridization positive and/or HER2 amplification by in situ hybridization or next-generation sequencing and/or activating ERBB2 mutation. Patients will receive the study treatment in 21-day cycles: Tucatinib 300 mg orally twice daily; T-DM1 3.6 mg/kg intravenously on Day 1. The primary objective is to determine the intracranial antitumor activity of the tucatinib and T-DM1 combination per the modified RECIST in patients with HER2+ metastatic solid tumors and brain metastases. The secondary objectives are to determine the intracranial antitumor activity per the RANO-BM criteria; to evaluate the safety and tolerability, the duration of intracranial response, the overall survival, the progression free survival, the systemic antitumor activity and clinical benefit rate in patients with HER2+ metastatic solid tumors and brain metastases. Exploratory objectives are to assess predictive and pharmacodynamic markers of response and to corelate them with clinical and molecular characteristics. The efficacy endpoint will be monitored using the Bayesian optimal phase 2 BOP2 design and safety and tolerability will be monitored based on Bayesian posterior probability. Restaging brain MRI and systemic scans will be performed every 6 weeks for the first 12 weeks, and every 9 weeks thereafter. The trial opened in May 2023 and is enrolling patients (NCT05673928). Citation Format: Ecaterina E. Dumbrava, Amber M. Kennon, Rashmi K. Murthy, Emma J. Montazari, Hussein Tawbi, Jing Li, Frederick F. Lang, Gisela Sanchez, Jianbo Wang, Isabella C. Glitza, Barbara J. O'Brien, Thomas Beckham, Todd Swanson, Martin C. Tom, Uyen M. Vu, Tanisha T. Darko, Tiantian Cai, Komal Shah, Funda Meric-Bernstam, Jordi Rodon. A phase II study of Tucatinib and Ado-trastuzumab Emtansine (T-DM1) in patients with HER2-positive metastatic solid tumors and metastases to brain (TUCATEMEB) [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 CT289.

Abstract CT292: Phase II study of pembrolizumab in combination with lenvatinib in patients with triple negative breast cancer (TNBC), non-small cell lung cancer (NSCLC), and other tumor types and brain metastases

Abstract Background: Many patients develop brain metastasis during the course of their disease and it represents the cause of death in more than half of them. The prognosis and survival of patients with brain metastases remains poor with limited palliative treatment options. Thus, there is a need to develop new strategies for the therapeutic management of patients with brain metastases. Inflammatory stimuli originating from CNS tumors may increase the permeability of the blood-brain barrier and promote immune cell activation and infiltration into tumors. Several studies have demonstrated now the efficacy of immune checkpoint inhibitors in patients with melanoma with active brain metastases. The modulation of VEGF-mediated immune suppression via angiogenesis inhibition may augment the activity of immune checkpoint inhibitors. Lenvatinib is an oral, potent multiple receptor tyrosine kinase inhibitor that selectively inhibits VEGFRs, VEGFR1 (FLT1), VEGFR2 (KDR), and VEGFR3 (FLT4), in addition to other pro-angiogenic and oncogenic pathway-related receptor tyrosine kinases. The combination of lenvatinib and pembrolizumab is approved for patients with metastatic endometrial carcinoma and renal cancer, and it is investigated in other tumor types with promising preliminary results. We hypothesize that pembrolizumab and lenvatinib will be an effective treatment for TNBC, NSCLC, and other solid tumor types with brain metastases by decreasing angiogenic tumor activity and improving antitumor T-cell activity. Methods: This is a single-center, open-label, multi-cohort Phase II study evaluating the efficacy and safety of pembrolizumab in combination with lenvatinib in patients with solid tumors and brain metastases. The study has 3 cohorts: triple negative breast cancer (TNBC), non-small cell lung cancer (NSCLC), and other solid tumor types with established or preliminary clinical evidence of efficacy of programmed cell death-1 (PD-1) and angiogenesis inhibitors. Eligible patients will have at least 1 unirraditated or progressing brain metastasis of 0.5-2 cm on brain MRI. The study is conducted using a Simon’s optimal two-stage design, and approximately 87 patients will be enrolled concurrently (n=29 per cohort). Pembrolizumab (200 mg intravenously on Day 1 of each cycle) and lenvatinib (20 mg orally once daily) are administered in 21-day cycles for a maximum of 24 months. The primary endpoint is intracranial objective response rate at 4 months as assessed by the modified Response Evaluation Criteria in Solid Tumors (mRECIST). Exploratory analyses will include evaluation of tissue and blood-based immune-related correlates of response to the pembrolizumab and lenvatinib combination. The first patient was enrolled in January 2022 and accrual of patients is ongoing (NCT05064280). Citation Format: Ecaterina E. Dumbrava, Emma J. Montazari, Uyen M. Vu, Tiantian Cai, Mehmet Altan, Nuhad K. Ibrahim, Debra N. Yeboa, Jing Li, Frederick F. Lang, Gisela Sanchez, Isabella C. Glitza, Barbara J. O'Brien, Rashmi K. Murthy, Jianbo Wang, Tanisha T. Darko, Denisse Velazquez, Komal Shah, Funda Meric-Bernstam, Hussein Tawbi, Jordi Rodon. Phase II study of pembrolizumab in combination with lenvatinib in patients with triple negative breast cancer (TNBC), non-small cell lung cancer (NSCLC), and other tumor types and brain metastases [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 CT292.

Brain Metastasis of Non-small Cell Lung Cancer After Disease-Free Survival of 5 years: Case Series and Comprehensive Literature Review

BackgroundIn the treatment of non-small cell lung cancer (NSCLC), a disease-free survival (DFS) of 5 years is a criterion for cure. This study aimed to evaluate the characteristics and outcomes of patients with brain metastases of NSCLC after a DFS of 5 years (late recurrent brain metastasis, LRBM). MethodsWe reviewed 1,281 consecutive patients with brain metastasis of lung cancer at a single institute between November 2014 and December 2022. Relevant articles were retrieved from PubMed. Only peer-reviewed journals published in English were included. ResultsSix patients (0.47%) showed LRBM. Three were male. The median age at lung cancer diagnosis was 45 years. The histological diagnosis of all patients was adenocarcinoma. Driver gene mutations were observed in five patients. The median latency period from lung cancer treatment to the development of brain metastasis was 13 years. All patients had no metastasis to any other organs and underwent craniotomies. The median follow-up duration after craniotomy was 3.5 years. No local intracranial recurrences were observed. Three patients had distant intracranial recurrences at 7, 2, and 0.6 years after craniotomy. Five patients survived for 8, 4, 3, 2, and 0.3 years after craniotomy. One patient experienced re-recurrence in the lung 4 years after craniotomy and died 3.7 years later. In our systematic review, only six studies described LRBM of NSCLC. ConclusionsLRBM is rare in patients with NSCLC. In our institution, many of these patients harbored driver gene mutations, and achieved long-term survival with aggressive local therapy. Multicenter analysis is mandatory.

Abstract 1500: Breast cancer-derived extracellular vesicles modulate the endocytic metabolism and morphodynamics of the endothelial cells of the blood-brain barrier

Abstract Breast cancer, particularly the triple-negative subtype, is the primary cause of brain metastasis in women, affecting 10-20% of breast cancer patients. Breast cancer patients who develop brain metastasis have few treatment options and a dismal prognosis with a median survival time of 6-16 months. We demonstrated, for the first time, that EVs derived from brain-seeking breast cancer cells (BrEVs) breach the intact blood-brain barrier (BBB) via transcytosis and cause a significantly increased incidence of breast-to-brain metastasis. Within this context, we are now studying the interactions between BrEVs and the endothelial cells (ECs) of the BBB. BrEVs were isolated by ultracentrifugation, characterized following the latest guidelines published by the International Society of Extracellular Vesicles (MISEV 2018) and tested in vitro using primary human brain ECs and in vivo using our mouse model of breast-to-brain metastasis. ECs were treated with BrEVs and analyzed using antibody-based assays, impedance measurements, genetic engineering and fixed and live cell imaging. The imaging results were analyzed using novel machine learning approaches to detect and describe, for the first time, EV-mediated morphodynamic changes at the brain EC barrier level. In vivo, we administered BrEVs intravenously to our models of breast-to-brain metastasis, followed by the analysis of mouse brains and their cerebral microvessels to examine microscopic structure and protein expression. Our studies show that (1) BrEVs target BBB ECs both in vitro and in vivo, causing significant variations of multiple proteins involved in the intracytoplasmic vesicles' long-recycling loop, (2) BrEVs are responsible for specific EC barrier function and morphodynamic changes and (3) BrEVs mediate, at least in part, their effect(s) through the delivery of specific micro RNAs. Taken together, our studies demonstrate that BrEVs have a significant impact on brain EC endocytic metabolism and morphodynamics, promoting transcytosis and sustaining breast-to-brain metastasis. Our findings increase our understanding of the early events that facilitate brain metastasis and have the potential to identify key regulators of brain metastasis formation. These results also inform and contribute to the development of EV-based therapeutic and diagnostic strategies for brain metastasis. (This work was supported by NIH R21 CA253051-01, the Breast Cancer Research Foundation, NIH T32 5T32HL007917-22 and the Nile Albright Research Foundation.) Citation Format: Sara Busatto, Golnaz Morad, Marsha A Moses. Breast cancer-derived extracellular vesicles modulate the endocytic metabolism and morphodynamics of the endothelial cells of the blood-brain barrier [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 1500.

Abstract 2296: Liquid biopsy of cerebrospinal fluid in breast to brain metastases

Abstract Up to 30% of patients with breast cancers will develop brain metastases, and this risk is especially high with HER2-positive cancers. For patients with central nervous system metastases, cerebrospinal fluid (CSF) liquid biopsies are a promising opportunity to monitor disease, inform treatment, and predict prognosis. This study explores the CSF liquid biopsy analytes from 3 patients with central nervous system metastases analyzed with the third generation non-enrichment high-definition single cell assay (HDSCA3.0) workflow. The detection of cellular analytes was compared between the CSF and matched peripheral blood (PB) samples. Circulating tumor cells (CTCs) were detected in the CSF but not the PB and were subsequently molecularly characterized by single cell genomics and targeted multiplexed proteomics to reveal a clonal population of phenotypically heterogeneous cells. There was a lack of concordance between CTCs and cfDNA of the CSF in the copy number alteration profiles. In an extracellular vesicle surface marker analysis of the CSF, there was a high signal among tetraspanin CD9/CD63/CD81, with CD81 signal the highest across all 3 patients. The data indicates that the CSF may be used as a diagnostic or potentially prognostic tool to measure and characterize disease burden. Citation Format: Stephanie N. Shishido, Amelia Marvit, Saul Priceman, Jana Portnow, Peter Kuhn. Liquid biopsy of cerebrospinal fluid in breast to brain metastases [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 2296.

Abstract 1557: Loss of lncRNA XIST promote brain metastasis by reshaping tumor lipid metabolism via upregulation of ACSL4

Abstract Metastatic disease is the main cause of cancer death, and the brain is one of the major sites of breast tumor metastasis. The median survival of breast cancer patients who developed brain metastases (BrM) is less than a year even with the advanced treatment such as stereotactic radiosurgery (SRS). Regardless of high clinical significance, the pathological mechanism of brain metastasis is still poorly understood. Previously, we found that loss of lncRNA XIST robustly promote metastasis and specially brain metastasis in breast cancer. However, the underlying molecular mechanism was not fully understood. In following study, we found that loss of XIST has significantly altered lipid metabolism of breast cancer cells specifically increasing lipid droplet amount and PUFA incorporation. Instead of de novo syntheses, XISTlow cancer cells acquire fatty acid by uptake from exogenous. We found that one X-linked gene, Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4) which are highly upregulated after loss of XIST is responsible for the altered lipid metabolism. ACSL4 activated the free polyunsaturated fatty acids (PUFAs) and lead to increased incorporation of PUFAs into phospholipids. On one hand, elevated ACLS4 expression leads to relative low PPAR pathway activation by decreasing the cellular free PUFA level which directly binds and activate PPAR. PPAR pathway is known to inhibit the expression of inflammatory cytokines which are important for cancer cells to establish brain metastasis. On the other hand, elevated ACSL4 expression enable cancer cells to metabolize the abundant PUFAs in the brain environment, thereby gaining survival advantage. However, increased PUFA incorporation into lipids especially phospholipids produce excess lipid ROS and sensitize cells to ferroptosis inducer such as RSL3. Our study has find out that brain microenvironment not only supports the outgrowth of XIST low cells by providing PUFAs for maintaining their metastatic properties but also sensitizes those cells to ferroptosis inducers, a potential therapy for treating this devastating disease. Citation Format: Yin Liu, Margaret R. Smith, Yuezhu Wang, Ralph D’Agostino, Jimmy Ruiz, Gregory L. Kucera, Lance D. Miller, Wencheng Li, Michael D. Chan, Michael Farris, Dawen Zhao, Fei Xing. Loss of lncRNA XIST promote brain metastasis by reshaping tumor lipid metabolism via upregulation of ACSL4 [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 1557.

Abstract 3785: Clinical and genomic characterization of melanoma brain metastases

Abstract Introduction: Melanoma has a high propensity for brain metastasis (BM). Although advancements in brain-penetrant treatments have resulted in improved central nervous system (CNS) disease control, BMs remain a significant cause of morbidity and mortality. The molecular features of melanoma BM are poorly defined, and there is an unmet need to identify biomarkers associated with CNS-specific outcomes. Methods: We retrospectively identified 109 patients with melanoma BM who underwent craniotomy at Memorial Sloan Kettering Cancer Center (MSK) between 01/2014 and 04/2023. BM specimens were sequenced using MSK-IMPACT, an FDA-approved next-generation sequencing assay covering 341-505 genes with 700X coverage. Clinical characteristics and CNS-specific outcomes were available from 107 patients; CNS-specific radiographic endpoints were verified through direct inspection of contrast-enhanced MRI imaging by a board-certified neuroradiologist. Clinical data included baseline characteristics, prior systemic or radiotherapy (RT), and CNS-directed follow up including recording local progression of disease (POD), regional POD, and development of leptomeningeal disease (LMD). Results: Majority (68%,73/107) patients were male with a median age at the time of primary diagnosis of 56 (range 3-88). Forty-eight patients (45%) had advanced disease (stages III and IV) at the time of initial diagnosis. At the time of BM development, half of the patients had 2-5 intracranial tumors present (50%) with a median diameter of largest BM of 33.4mm (range .9mm-64mm). The median KPS was 80 at the time of BM diagnosis, and 79% had neurologic symptoms prior to resection. 81 patients (76%) were treatment naïve at the time of resection and 56 patients (53%) developed CNS recurrence with the majority of those having local POD (29%,16/56) followed closely by regional POD of 1 lesion (25%,14/56). The most frequent genomic alterations in the cohort were TERT (87%), CDKN2A (50%), BRAF (43%), NRAS (28%), and PTEN (25%). The median fraction genome altered was 0.3047 and the median tumor mutational burden was 13.2 muts/Mb. We compared the genomic profiles of BM tumors of patients that had no progression, local POD, regional POD, and LMD. Compared to patients with no progression, patients with local POD were more likely to have RB1 alterations (18.1% vs 2.1%, p = 0.04, q = 0.83) and patients with LMD were less likely to have TERT alterations (62.5% vs 93.8%, p = 0.03, q = 0.75). Conclusions: Our analysis between genomic markers and clinical outcomes in melanoma BM reveals genomic features which may improve prediction and treatment strategies. Citation Format: Michel Padilla Mazzeo, Henry S. Walch, Rahul Kumar, Jordan Eichholz, Claire Cooper, Nishta Nandakumar, Junchao Shen, Ishaani Khatri, Luke Del Balzo, Anna Skakodub, Emily Miao, Daniel W. Kelly, Kenny Kwok Hei Yu, Jessica Wilcox, Brandon S. Imber, Yao Yu, Yoshiya Yamada, Harish Vasudevan, Ahmet Ilica, Nikolaus Schultz, Luke R. Pike. Clinical and genomic characterization of melanoma brain metastases [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 3785.

Abstract 6465: A population-based analysis of brain metastasis burden and management in 8705 small cell lung cancer patients

Abstract Introduction: Patients with small cell lung cancer (SCLC) have historically been characterized by poor overall survival (OS) and high risk for brain metastases (BM), but large-scale real-world evidence on clinical presentation and treatment in this population is lacking. Methods: The aim of this study was to describe the clinical characteristics and outcomes of patients with SCLC and BM in Ontario, Canada. This retrospective cohort study included all patients in Ontario, Canada, who were diagnosed with SCLC between April 2010 and March 2018. Data were analyzed between June 2022 and July 2023. Kaplan-Meier and multivariable Cox regression analyses were performed to compare overall survival (OS) between patient cohorts stratified by disease stage, BM diagnosis, or first-line intracranial treatment modality. Results: 8705 patients were included. Median age at diagnosis was 68 years (range 18-103). Median OS of all patients was 7.46 months (95% confidence interval, CI, 7.23-7.69). 32% (n=2686) of patients developed BM (synchronous, 43.7%; asynchronous, 56.3%) and had median OS of 9.76 months (95% CI, 9.36-10.22). 102, 1654, and 880 patients received stereotactic radiosurgery (SRS), whole brain radiation therapy (WBRT), and no treatment, respectively, for their BM in the first-line setting or after prophylactic cranial irradiation (PCI). In propensity score-matched analyses, OS was equivocal between SRS- and WBRT-treated cohorts among patients who did not receive PCI (hazard ratio, HR, 1.18, 95% CI, 0.75-1.81) and those who received PCI prior to BM development (HR, 0.77, 95% CI, 0.53-1.13). Conclusions: Survival for patients with SCLC remains poor, and many patients present with BMs. With careful selection, patients with SCLC may benefit from SRS treatment. Citation Format: Karolina Gaebe, Anders W. Erickson, Sarah Chen, Arjun Sahgal, Benjamin H. Lok, Kelvin K. Chan, Sunit Das. A population-based analysis of brain metastasis burden and management in 8705 small cell lung cancer patients [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 6465.

Pre-operative vs. post-operative stereotactic radiosurgery for operative metastatic brain tumors: study protocol for a phase III clinical trial

Background and ObjectivesAlmost one third of cancer patients in the United States will develop brain metastases on an annual basis. Surgical resection is indicated in the setting of brain metastases for reasons, such as maximizing local control in select patients, decompression of mass effect, and/or tissue diagnosis. The current standard of care following resection of a brain metastasis has shifted from whole brain radiation therapy to post-operative stereotactic radiosurgery (SRS). However, there is a significant rate of local recurrence within one year of postoperative SRS. Emerging retrospective and prospective data suggest pre-operative SRS is a safe and potentially effective treatment paradigm for surgical brain metastases. This trial intends to determine, for patients with an indication for resection of a brain metastasis, whether there is an increase in the time to a composite endpoint of adverse outcomes; including the first occurrence of either: local recurrence, leptomeningeal disease, or symptomatic radiation brain necrosis - in patients who receive pre-operative SRS as compared to patients who receive post-operative SRS.MethodsThis randomized phase III clinical trial compares pre-operative with post-operative SRS for brain metastases. A dynamic random allocation procedure will allocate an equal number of patients to each arm: pre-operative SRS followed by surgery or surgery followed by post-operative SRS.Expected outcomesIf pre-operative SRS improves outcomes relative to post-operative SRS, this will establish pre-operative SRS as superior. If post-operative SRS proves superior to pre-operative SRS, it will remain a standard of care and halt the increasing utilization of pre-operative SRS. If there is no difference in pre- versus post-operative SRS, then pre-operative SRS may still be preferred, given patient convenience and the potential for a condensed timeline.DiscussionEmerging retrospective and prospective data have demonstrated some benefits of pre-op SRS vs. post-op SRS. This study will show whether there is an increase in the time to the composite endpoint. Additionally, the study will compare overall survival; patient-reported outcomes; morbidity; completion of planned therapies; time to systemic therapy; time to regional progression; time to CNS progression; time to subsequent treatment; rate of radiation necrosis; rate of local recurrence; and rate of leptomeningeal disease.Trial registration numberNCT03750227 (Registration date: 21/11/2018).

Survival Analysis of Male Patients with Brain Metastases at Initial Breast Cancer Diagnosis over the Last Decade.

Breast cancer in men represents approximately 1% of all breast cancer diagnoses. Among all patients with breast cancer, approximately 30% will develop brain metastases. Over the past decade, there have been multiple advances in the treatment of metastatic breast cancer; however, long-term outcomes of this presentation in male patients are lacking. We evaluated male patients with de novo stage IV breast cancer using the Surveillance, Epidemiology and End Results (SEER) database from 2010 to 2019. Overall survival (OS) was estimated using the Kaplan-Meier method and differences between groups were compared using log rank tests. In total, 22 male patients with brain metastases at initial breast cancer diagnosis were included. Patients with HR-positive/HER2-negative tumors had the longest OS (median 13 months). Factors associated with shorter overall survival were advanced age, unmarried marital status, lower household income, and grade III disease, among others. Brain metastases remains an unmet medical need for patients with breast cancer; the development of new drugs may provide an improvement in overall survival for male patients in the future.

Abstract B004: Clinico-genomic characteristics of breast cancer brain metastasis: A multi-institutional analysis from AACR Project GENIE BPC

Abstract Purpose: The presence of Her2 amplification is associated with an increased risk of developing brain metastases. Brain metastases in breast cancer can be particularly challenging and have significant implications for prognosis and treatment. Common Her2-targeted therapies and small tyrosine kinase inhibitors have demonstrated the ability to penetrate the blood brain barrier and be effective in treating brain metastases. We investigated the clinico-genomic characteristics and the prognosis of brain metastasis in patients with breast cancer. Experimental design: Patients with breast cancer whose tumors underwent targeted sequencing from 2013-2018 at age 56 years old or younger at three institutions from the American Association of Cancer Research Genomics Evidence Neoplasia Information Exchange Biopharma Collaborative (AACR Project GENIE BPC) registry were selected for data curation. The PRISSMM data model was used for real world outcomes including overall survival. We analyzed clinical and genomic characteristics, treatment, and clinical outcome data among patients with and without brain metastases, stratified by Her2 amplification and hormone-receptor status (Her2+ vs. Her2-/HR+ vs. triple-negative breast cancer (TNBC)). We explored the top 20 most frequently altered genes that were included on at least 20% of sequencing panels. Results: A total of 1019 patients with breast cancer along with their receptor subtype information were included in the study (110 patients were excluded due to either post- mortem sequencing or unknown receptor subtype). Among them, 336 (33%) patients were identified to have developed brain metastasis (n=87 with Her2+; n=181 with Her2-/HR+; and n=68 with TNBC). At time of advanced disease, the brain was the first and only distant site of disease in 41/336 (12%) and detected with extracranial sites of disease in 22/336 (7%) patients. For patients presenting with stage I-III breast cancer, the cumulative incidence of brain metastasis at 5 years from breast cancer diagnosis was higher in those with TNBC (35%; 95% CI: 25, 50) as compared to 24% (95% CI: 16, 37) and 21% (95% CI: 15, 29) for those with Her2+ and Her2-/HR+ subtypes, respectively. Median overall survival from brain metastasis was significantly longer (log-rank p&amp;lt;0.001) for those with Her2+ disease (19m, 95% CI: 13, 36) compared to those with Her2-/HR+ (8.9m, 95% CI: 6.3, 15) or TNBC (7.4m, 95% CI: 4.6, 11). Among patients who ever developed brain metastases, IKZF3 alterations occurred in 71% (20/28) of Her2+ patients but did not occur in either Her2- subtype. Additionally, frequencies of CDK12, MYC, and PTEN alterations differed across subtypes. Conclusions: Brain involvement at metastatic presentation conferred a higher risk of death than brain-sparing metastases. Triple negative and Her2+ histologies were associated with higher risk of brain involvement at metastasis presentation. Further exploration by treatment received across receptor subtypes and genomic alterations will be presented. Citation Format: Samantha Brown, Hannah E. Fuchs, Jessica A. Lavery, Katherine S. Panageas, Nelson S. Moss. Clinico-genomic characteristics of breast cancer brain metastasis: A multi-institutional analysis from AACR Project GENIE BPC [abstract]. In: Proceedings of the AACR Special Conference on Brain Cancer; 2023 Oct 19-22; Minneapolis, Minnesota. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_1):Abstract nr B004.

AI-guided histopathology predicts brain metastasis in lung cancer patients.

Brain metastases can occur in nearly half of patients with early and locally advanced (stage I-III) non-small cell lung cancer (NSCLC). There are no reliable histopathologic or molecular means to identify those who are likely to develop brain metastases. We sought to determine if deep learning (DL) could be applied to routine H&E-stained primary tumor tissue sections from stage I-III NSCLC patients to predict the development of brain metastasis. Diagnostic slides from 158 patients with stage I-III NSCLC followed for at least 5 years for the development of brain metastases (Met+, 65 patients) versus no progression (Met-, 93 patients) were subjected to whole-slide imaging. Three separate iterations were performed by first selecting 118 cases (45 Met+, 73 Met-) to train and validate the DL algorithm, while 40 separate cases (20 Met+, 20 Met-) were used as the test set. The DL algorithm results were compared to a blinded review by four expert pathologists. The DL-based algorithm was able to distinguish the eventual development of brain metastases with an accuracy of 87% (p < 0.0001) compared with an average of 57.3% by the four pathologists and appears to be particularly useful in predicting brain metastases in stage I patients. The DL algorithm appears to focus on a complex set of histologic features. DL-based algorithms using routine H&E-stained slides may identify patients who are likely to develop brain metastases from those who will remain disease free over extended (>5 year) follow-up and may thus be spared systemic therapy. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Clinical Outcomes of Patients with HER2 Positive Metastatic Breast Cancer to the Brain, with First-Line Trastuzumab, Pertuzumab and Chemotherapy, in a Real-World Setting.

In this observational study, we analyzed the treatment patterns and clinical outcomes of patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (mBC) who developed brain metastases during their disease in a 2.7 million-member public health-provider in Israel. Newly diagnosed patients with mBC who initiated first-line treatment between January 2013 and June 2021 were identified. Time on treatment (ToT) and overall survival (OS) were assessed at a minimum of 6 months follow-up (cutoff: December 2021). We identified a total of 61 patients: 98.4% females, median age 50 years (IQR = 44-63), 85% invasive ductal tumors, 44% hormone receptor positive, 51% performance status 0-1. The median duration of follow-up was 6.2 years. All patients initiated a combination treatment of trastuzumab, pertuzumab, and chemotherapy (TPC), and 72% moved to second-line treatment during the study follow-up period (82% ado-trastuzumab emtansine). The median ToT for first-line and second-line treatments were 16.9 months (95% CI = 13.9-27.7) and 7.9 months (95% CI = 5.6-10.9), respectively. The median overall survival (OS) was 45.5 months (95% CI = 35.4-71.2) from the initiation of first-line treatment. When considering the timing of brain metastases, the median OS was 36.3 months (95% CI = 10.0-NR) for those diagnosed upfront (n = 15, 25%), 59.1 months (95% CI = 32.5-NR) for those diagnosed while on TPC (n = 25, 41%), and 40.8 months (95% CI = 35.4-NR) for those diagnosed at a later stage (n = 21, 34%). The median OS from brain metastases diagnosis was 25.1 months (95% CI = 17.0-34.6). Patients with upfront brain involvement at the time of mBC diagnosis had shorter survival compared to those who started TPC without brain metastases. Nonetheless, the overall results from this study compare favorably with previous studies and contribute to understanding the value of traditional treatment options, which will serve as a baseline for future treatment strategies in the real-world setting.

Focused ultrasound and microbubble induced changes in the phenotype of breast cancer cell lines

Up to 10%–15% of patients with breast cancer (BC), particularly those with triple negative (TNBC) and HER2 positive subtypes, develop brain metastases. Despite aggressive treatment, the median survival for patients is 15 months. Treatment of brain metastases is challenging due to the blood–brain barrier (BBB) that limits the passage of molecules commonly used to treat primary BC into the brain parenchyma. Focused Ultrasound (FUS) and Microbubble (MB) are a non-invasive, image-guided therapeutic modality that can create a reversible, safe, and transient opening of the BBB. While this burgeoning area of research has progressed to clinical trials, the direct effects of FUS + MBs in the absence of therapeutic agents on tumor cells are poorly characterized. Therefore, this study aims to identify the FUS+MB induced changes in migration, invasion, and proliferation of representative brain-derived (BD) BC cell lines, namely, BD-MDA-MB-231 and BD-SKBR3 post-sonication in comparison to untreated cells. Results from these experiments will help guide future in-vivo studies evaluating the impact of FUS+MB on brain metastases to better understand its therapeutic implications and applications for patients.

Spine Metastasis Is Associated with the Development of Brain Metastasis in Non-Small-Cell Lung Cancer Patients.

Background and Objectives: The mechanisms involved in the development of brain metastasis (BM) remain elusive. Here, we investigated whether BM is associated with spine involvement in patients with non-small-cell lung cancer (NSCLC). Materials and Methods: A consecutive 902 patients with metastatic NSCLC were included from the Inha Lung Cancer Cohort. Patients with BM at diagnosis or subsequent BM development were evaluated for both spine involvement in NSCLC and anatomic proximity of BM to the cerebrospinal fluid (CSF) space. Results: At diagnosis, BM was found in 238 patients (26.4%) and bone metastasis was found in 393 patients (43.6%). In patients with bone metastasis, spine involvement was present in 280 patients. BM subsequently developed in 82 (28.9%) of 284 patients without BM at diagnosis. The presence of spine metastasis was associated with BM at diagnosis and subsequent BM development (adjusted odd ratios and 95% confidence intervals = 2.42 and 1.74-3.37, p < 0.001; 1.94 and 1.19-3.18, p = 0.008, respectively). Most patients with spine metastasis, either with BM at diagnosis or subsequent BM, showed BM lesions located adjacent (within 5mm) to the CSF space (93.8% of BM at the diagnosis, 100% of subsequent BM). Conclusions: These findings suggest that the presence of spine involvement is a risk factor for BM development in NSCLC patients with bone metastasis.

Whole-brain radiation therapy plus simultaneous integrated boost for brain metastases from breast cancers.

The effect of whole-brain radiation therapy (WBRT) plus simultaneous integrated boost (SIB) in brain metastasis from breast cancers has not been demonstrated. In this single-center retrospective study, we reviewed consecutive breast cancer patients who developed brain metastasis and were treated with hypofractionated radiation therapy plus WBRT using intensity-modulated radiation therapy (IMRT)-SIB approaches. We analyzed clinical outcomes, prognostic factors and patterns of treatment failure. A total of 27 patients were eligible for analysis. Four (14.8%) patients achieved clinical complete response and 14 (51.9%) had partial response of brain lesions. The other nine patients were not evaluated for brain tumor response. The median brain progression-free survival was 8.60 (95% CI [6.43-13.33]) months and the median overall survival was 16.8 (95% CI [13.3-27.7]) months. Three patients had in-field failure, five had out-field failure and two had in-field and out-field failure. WBRT plus SIB led to improved tumor control and clinical outcome in breast cancer patients with brain metastasis.