Citations

TPS649 Background: While advancements in early-stage breast cancer (ESBC) treatment have improved survival, disease recurrence and therapeutic resistance remain significant challenges. Current biomarkers guide initial treatment, yet novel diagnostics are required to improve risk stratification and recurrence prediction. Circulating tumor DNA (ctDNA) offers a non-invasive method for detecting minimal residual disease (MRD), potentially enabling the identification of molecular relapse before radiographic progression. However, deeper validation of ctDNA kinetics across the treatment continuum is needed to inform precision oncology strategies in ESBC. Additionally, the logistical complexity of tissue-dependent assays presents a barrier to scalability. In order to address these gaps, the purpose of the GEMINI-BREAST study is to evaluate a methylation-based, tissue-free ctDNA assay (Tempus xM) and integrate this with comprehensive clinical and multi-omic data to determine prognostic utility for invasive disease-free survival (iDFS) and long term outcomes in patients with ESBC. Methods: GEMINI-BREAST (NCT07211178) is a prospective, non-interventional, multi-center study enrolling up to 900 participants with ESBC treated with curative intent. Eligible patients enroll into one of three analytical cohorts (n ~ 300 each): Cohort 1 enrolls pre-neoadjuvant therapy (high-risk HR+/HER2- [Stage II-III], HER2+ [Stage II-III], or TNBC [Stage I-III]); Cohort 2 enrolls post-surgery/pre-adjuvant therapy (same subtypes, no evidence of disease); and Cohort 3 enrolls long-term survivors (high-risk HR+/HER2- [Stage II-III], ≥ 5 years since diagnosis). Longitudinal blood samples for ctDNA analysis and archival tissue for NGS are collected at standard-of-care intervals, including, as applicable: pre-neoadjuvant, neoadjuvant on-treatment (weeks 3, 6, 12) and post-treatment, post-surgical/pre-adjuvant, adjuvant on-treatment (every 3 months), end of definitive therapy, surveillance for up to 5 years (every 3-6 months for Cohorts 1/2; every 6-12 months for Cohort 3), and at progression/recurrence. The primary objective is to evaluate the association between ctDNA dynamics (Cohort 1) or MRD status (Cohort 2/3) and iDFS, with secondary endpoints assessing overall survival, lead time to recurrence, and the predictive value of ctDNA clearance for pathological complete response. Recruitment is currently ongoing at U.S. sites. Clinical trial information: NCT07211178 .

e16159 Background: Pivotal trials established atezolizumab-bevacizumab and durvalumab-tremelimumab as first-line therapies for unresectable hepatocellular carcinoma (HCC). Atezolizumab plus bevacizumab demonstrated superior survival outcomes compared to sorafenib for unresectable HCC in the IMbrave150 trial in 2020, while durvalumab plus tremelimumab showed superior survival in the HIMALAYA trial in 2022. However, data on head-to-head comparison of these two combinations as first-line systemic therapy for the patient with decompensated HCC are limited. This study aims to compare survival outcomes between these two treatment regimens in decompensated HCC patients to address a critical gap in the current literature, as decompensated patients have largely been excluded from clinical trials. Methods: This retrospective study utilized electronic health records from 146 U.S. healthcare organizations within the TriNetX Network. Adults aged ≥21 years diagnosed with decompensated HCC receiving atezolizumab/bevacizumab and durvalumab/tremelimumab from 10/21/2022 to 8/20/2024 were included. The comparison group received atezolizumab/bevacizumab, and the control group received durvalumab/tremelimumab. The primary outcome was all-cause mortality. A 1:1 propensity score matching was conducted to balance baseline characteristics (age, gender, race/ethnicity, lab results including liver function tests, platelet counts, INR, gamma glutamyl transferase, alpha-fetoprotein, and underlying liver diseases). Kaplan–Meier survival analysis and Cox regression was used to estimate the mortality risk. Subgroup analysis was stratified by HCC etiology. Results: A total of 302 and 664 patients received durvalumab/tremelimumab, atezolizumab/bevacizumab, respectively. After propensity matching, 253 patients per group were included. Median OS was 283 days with durvalumab/tremelimumab and 391 days with atezolizumab/bevacizumab. The two treatment regimens showed no significant difference in survival (hazard ratio [HR]: 0.875, 95% confidence intervals [CI] 0.696–1.101, p=0.254). Subgroup analyses demonstrated no significant differences in survival between the two groups of patients in MASLD (HR: 0.698, 95% CI: 0.468–1.040), alcohol associated liver disease (HR: 0.821, 95% CI: 0.603–1.118), and chronic viral hepatitis (HR: 0.852, 95% CI: 0.596–1.219). Conclusions: There was no statistically significant difference in survival outcomes between atezolizumab plus bevacizumab and durvalumab plus tremelimumab in patients with decompensated advanced HCC. These results support current real-world practice in which both regimens may be considered viable first-line treatment options in this high-risk population with liver decompensation.

SUMMARY Neurodegenerative diseases are often accompanied by systemic comorbidities, including changes in bone health, but the molecular relationship between neurodegeneration, skeletal decline, and cellular senescence remains poorly understood. In this study, we investigated sex-specific changes in circulating bone- and senescence-related proteins across the spectrum of Alzheimer’s disease(AD), Lewbody dementia(LB) and Parkinson’s disease(PD). Plasma proteomic profiling was performed on samples from 408 participants deeply phenotyped for neurodegenerative diseases, followed by differential protein and pathway analyses. This study reveals sex-dependent alterations in bone and senescence-related circulating proteins in AD-related, PD and LB-related neurodegenerative diseases, providing insights into the complex relationship between neurodegeneration and bone health. Several candidate proteins were also associated with established plasma neurodegeneration biomarkers, particularly pTau181. Pathway analyses revealed shared mitochondrial and metabolic dysfunction across neurodegenerative diseases, with disease-specific features including vesicle trafficking disruption in AD and inflammatory-senescence pathways in LB, plus sex-divergent patterns in inflammatory signaling and bone-related pathways.

Abstract The genetic contributions of the X chromosome to Alzheimer’s disease (AD) remain poorly understood yet are expected to importantly shape sex differences in AD. We therefore performed large-scale X-chromosome-wide association studies (N=1,240,451), evaluating differential risk due to sex, APOE *4, and escape from X-chromosome inactivation, finding most X-linked loci appear relevant to female-biased AD etiology. In evaluating genetic pleiotropy with hormonal, lipid, and brain imaging traits, we discovered X-linked AD loci converged on white matter traits, particularly in the anterior corona radiata and splenium of the corpus callosum. Through brain-centric functional genomics analyses, we then nominated candidate causal genes, including 5 that appeared highly robust. Notably, we found the escape gene RBBP7 decreases AD risk in APOE *4 carriers likely through higher expression in excitatory neurons to counter tau-related neurodegeneration. Altogether, we provide an atlas of sex and APOE *4-informed candidate X-linked AD risk loci, genes, and mechanisms that will guide future studies.

Abstract Multiple Myeloma is the second most common hematologic malignancy among US adults and remains incurable. Immunotherapies, including bispecific T cell engagers (BiTEs) targeting BCMA, have greatly improved outcomes. However, a significant fraction of patients still fail to respond, or develop resistant disease. Conventional models of T cell cytotoxicity focus on delivery of perforin- and granzyme-containing granules following antigen recognition and T cell activation, an inefficient mode of killing that requires effector-to-target cell contact. Activated T cells, however, also secrete cytokines capable of diffusing and acting on distant targets. This raises the possibility of paracrine killing, in which these cytokines induce tumor cell death independently of cell-cell contact.Tumor necrosis factor (TNF) is a key cytokine released during T cell activation and is unique in that it can drive either cell survival or cell death. Although most cells default to cell survival and NFkB-mediated inflammation, several modulators can shift this survival signaling toward cell death. We therefore hypothesized that sensitizing Myeloma cells to TNF could enable T cell paracrine killing and enhance the efficacy of anti-Myeloma T cell immunotherapies.To test this, we first established an in vitro model of clinical response to Teclistamab, a BCMA-directed BiTE, using Multiple Myeloma cell lines that displayed sensitive, intermediate, or resistant responses to T cell killing. Combining these data with assays of cytokine sensitivity and receptor expression, we found that susceptibility to TNF-mediated cell death was a major determinant of Teclistamab sensitivity. This correlation was further supported by reduction or complete abrogation of Teclistamab T cell killing of sensitive Myeloma cell lines when soluble TNF was neutralized from these co-cultures using monoclonal antibodies. Pharmacologic inhibition and CRISPR-mediated deletion of known regulators of TNF survival-signaling further sensitized Myeloma cells to both TNF and T cell killing. In the absence of these regulators, BCMA-negative myeloma targets retained sensitivity to Teclistamab, supporting the idea that the main mechanism of cell death was indeed paracrine killing.Together, these findings establish a direct link between TNF sensitivity and T cell-mediated killing of Myeloma cells, and support TNF-driven paracrine killing as a dominant mechanism of response to Teclistamab. Enhancing this TNF-mediated death signaling may therefore represent a strategy to overcome resistance and improve clinical efficacy of T cell-based immunotherapies in Multiple Myeloma. Citation Format: Allison Carr, Elise Sintim-Aboagye, Adrian Ting, . TNF-driven paracrine killing determines the cytotoxic efficacy of Teclistamab in Myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 1636.

Background Immune exclusion inhibits antitumor immunity and response to immunotherapy, but its mechanisms remain poorly defined. In triple-negative breast cancer (TNBC), an aggressive and generally immune-rich subtype, an immune-cold microenvironment predicts poor prognosis due to a limited response to chemotherapy and immune checkpoint inhibitors. This study aimed to identify mechanisms regulating immune infiltration in TNBC. Methods We performed spatial transcriptomic analysis comparing immune-enriched versus immune-cold treatment-naïve TNBCs. Functional analyses, including loss-of-function and reconstitution experiments, were conducted to investigate the role of trophoblast cell-surface antigen 2 (TROP2), a key target of anticancer antibody drug conjugates (ADCs), in promoting TNBC progression. A humanized TROP2 syngeneic TNBC model was used to assess the effects of TROP2-targeting in combination with anti-programmed cell death protein 1 (PD-1) therapy. Additionally, data from patients treated with immune checkpoint blockade were used to test hypotheses from the preclinical findings. Results We reveal that TROP2 controls barrier-mediated immune exclusion in TNBC through claudin 7 association and tight junction regulation. TROP2 expression is inversely correlated with T-cell infiltration and predicts poor outcomes in TNBC. We demonstrate that TROP2 is sufficient to drive tumor progression in vivo in a CD8 T cell-dependent manner, while its loss deregulates expression and localization of multiple tight junction proteins, enabling T-cell infiltration. We show that TROP2 targeting via hRS7, the antibody component of the ADC sacituzumab govitecan, enhances the anti-PD-1 response and improves T-cell accessibility and effector function. Correspondingly, TROP2 expression is highly associated with lack of response to anti-PD-1 therapy in human breast cancer. Conclusions This study defines a new mechanism of barrier-mediated immune exclusion in cancer controlled by TROP2-dependent tight junctions. This mechanism drives tumor progression but can be targeted via TROP2-directed therapy to activate antitumor immunity and enhance immunotherapy response.

Obesity is a persistent public health issue, often resulting in metabolic complications such as insulin resistance (IR). The secretion of pro-inflammatory cytokines from adipose tissue (AT) is increased during obesity, contributing to the impairment of systemic insulin sensitivity. While interventions in animal models have shown that reducing inflammation restores insulin sensitivity, human studies reducing systemic inflammation have produced inconsistent results. We recently demonstrated that three months of high-dose (4 g/daily) ω-3PUFA (fish oil, FO) supplementation improved insulin sensitivity, and decreased systemic and AT inflammation in individuals with obesity (BMI ≥ 30 kg/m2). Given recent studies highlighting the involvement of microRNA (miRNA) in inflammatory cytokine production, we investigated the effect of ω-3PUFA supplementation on AT miRNA expression in this cohort. AT biopsies were collected before and after ω-3PUFA supplementation. miRNA was processed on the Affymetrix miRNA 4.0 GeneChip and analyzed using existing inflammatory gene sets sourced from MSigDB. Unbiased, differentially expressed miRNA analysis identified miR-4498 and miR-5689 as significantly increased after three months of ω-3PUFA supplementation. Real-time PCR confirmed bioinformatic analysis findings. Our study reports the modulation of miRNA in AT, reductions in systemic and AT markers of inflammation, and the improvement of IR post ω-3PUFA supplementation. Further research is needed to elucidate the link between miR-4498, miR-5689, and whole-body insulin sensitivity.

Background Breast phyllodes tumours (PT) are rare biphasic neoplasms consisting of epithelial and stromal components. They are classified into benign, borderline and malignant categories. Diagnosing and grading PTs present a challenge for pathologists, as there are multiple histological parameters and their own tiers. We aim to investigate the potential role of artificial intelligence (AI) as a diagnostic aid in determining PT grade. Materials and methods We investigated 15 PT whole slide images (WSIs), comprising 5 benign, 5 borderline and 5 malignant cases. We sought to classify and retrieve the most relevant WSIs by matching histological features at different patch sizes, using the Yottixel framework for WSI processing. Patches were extracted at a 20× magnification level. We then used the KimiaNet to extract feature vectors and transformed these into barcode representations. Barcodes of a query WSI were compared with those of others in the archive, allowing us to identify the most similar WSI and determine the PT grades from histological similarities. Results We utilized ‘majority‐n accuracy’ as a measure of correctness, that is when the majority of the top‐n search results have the correct diagnosis as the query patient. We achieved a maximum reported accuracy of 67%, with a 3000 × 3000 patch size when grading PT at majority voting with n = 4. Conclusion Despite the small sample size and absence of fine‐tuning, our study demonstrated the potential of AI‐based PT grade stratification using various patch sizes through histological matching. This serves as a preliminary proof of concept, with the prospect of refinement for potential routine clinical application.

Abstract Polycomb group (PcG) proteins form the Polycomb Repressive Complexes 1 and 2 (PRC1/2), which regulate gene expression through histone modifications. Their dysregulation is implicated in cancer. Genomic analysis of prostate cancer datasets revealed a striking divergence: PRC1 genes are frequently amplified in metastatic disease (SU2C), correlating with poor survival, higher tumor mutational burden (TMB), and enhanced androgen receptor (AR) signaling. In contrast, primary prostate cancer (PRAD) is characterized by recurrent deletion of the 3p13 locus, which harbors the gene for the non-canonical PRC1 subunit RYBP. Transcriptomic analysis indicated that RYBP loss derepresses gene expression, consistent with its role in transcriptional repression. Functionally, RYBP expression positively correlates with AR activity and negatively associates with neuroendocrine (NEPC) differentiation. Spatial and single-cell transcriptomics further show that RYBP is enriched in normal epithelial cells but downregulated in tumor cells. Besides, tumors with lower RYBP expression exhibit an immunosuppressive microenvironment, characterized by increased regulatory T cells. Collectively, these findings position RYBP deletion not only as a novel DNA-based biomarker for primary prostate cancer but also as a pivotal epigenetic deregulation event that coordinates oncogenic signaling and lineage plasticity.