San Antonio, Texas — December 9, 2025 — Leads & Copy — Tempus AI, Inc. (NASDAQ: TEM) has announced that ten abstracts have been accepted for presentation at the 2025 San Antonio Breast Cancer Symposium (SABCS), scheduled for December 9–12 at the Henry B. González Convention Center in San Antonio, Texas.
The research underscores the potential of multimodal data to unravel the complexities of breast cancer, according to Dr. Ezra Cohen, MD, Chief Medical Officer of Oncology at Tempus. He noted that integrating genomic, transcriptomic, and real-world clinical data facilitates the discovery of specific molecular drivers of progression and resistance, beyond broad disease classifications. These insights are essential for identifying patient populations that may benefit from novel therapies and for optimizing treatment strategies to improve outcomes for individuals with advanced disease.
Tempus will present its scientific and clinical research findings through ten poster presentations:
Integrative Modeling of Multimodal Real-World Data
A machine learning model was developed utilizing clinical, genomic, and transcriptomic features to stratify patients with estrogen receptor (ER)-Positive/Human Epidermal Growth Factor Receptor 2 (HER2)-Negative metastatic breast cancer. The study aimed to improve risk stratification of first-line CDK4/6 inhibitor outcomes and identify predictors of response. The study demonstrated that multimodal real-world data collected during routine care can provide insights into the biology of response to CDK4/6 inhibitors and help improve patient stratification. The presentation is scheduled for Wednesday, December 10, 2025, from 12:30 p.m. to 2:30 p.m. CDT (Presentation Number: PS1-11-08).
Distinct Transcriptional and Immunosuppressive Microenvironment Signatures
The study compared transcriptomic and immune profiles in hormone receptor-positive (HR+)/HER2- metastatic breast cancer across wild-type, PIK3CA-mutant, ESR1-mutant, and co-mutant groups. Findings indicated that SFRP2 downregulation was specific to ESR1-mutant tumors, while SCGB2A2 was upregulated in PIK3CA-mutant and co-mutant tumors, suggesting its potential as a diagnostic and therapeutic target. Immune analysis revealed increased M2 macrophages and regulatory T cells in PIK3CA-mutant and co-mutant tumors, with the most pronounced immunosuppressive microenvironment in PIK3CA-mutant cases. This presentation is scheduled for Wednesday, December 10, 2025, from 12:30 p.m. to 2:30 p.m. CDT (Presentation Number: PS1-11-22).
Clinical and Molecular Landscape of ESR1 and PIK3CA Co-Mutated Hormone Receptor–Positive Metastatic Breast Cancer
The study analyzed 8,626 patients, revealing that distinct mutation groups—no-MUT, PIK3CA-MUT, ESR1-MUT, and co-MUT (PIK3CA + ESR1)—exhibited unique clinical and genomic features; co-MUT was linked to more bone metastases, elevated tumor mutational burden, increased polyclonality, and shorter real-world overall survival. The frequency of ESR1 and co-mutations was higher in patients who underwent late molecular testing, indicating these alterations often emerge after extended endocrine therapy and highlighting the importance of timing in molecular assessment for guiding treatment strategies. This presentation is scheduled for Wednesday, December 10, 2025, from 12:30 p.m. to 2:30 p.m. CDT (Presentation Number: PS1-11-16).
Clinicogenomic and Immune Profiles of Male Breast Cancer by Race
A real-world analysis of male breast cancer revealed broadly similar clinicogenomic profiles between Black and White patients, with HR+/HER2-negative and luminal subtypes predominating. Notable immune microenvironment differences—lower M2 macrophage infiltration and higher PD-L1 negativity in Black patients—may impact immunotherapy response and warrant further research into racial variation. This presentation is scheduled for Wednesday, December 10, 2025, from 5:00 p.m. to 6:30 p.m. CDT (Presentation Number: PS2-06-28).
Cathepsin Protease Expression and Therapeutic Outcomes to Trastuzumab Deruxtecan (T-DXd) in Metastatic Breast Cancer
The study characterized pre-treatment expression of cathepsin proteases prior to T-DXd (cleavable linker) vs. T-DM1 (non-cleavable linker) treatment to understand their impact on clinical outcomes in metastatic breast cancer using the Tempus real-world database. The results indicated that among T-DXd treated patients, high cathepsin B and L protease expression was associated with improved outcomes in patients with HR+/HER2- disease, whereas in HER2+ patients, high expression of these proteases was associated with worse survival. In contrast, in the T-DM1 cohort there were no significant associations between protease expression and OS. This highlights the potential role of proteases as biomarkers of response to T-DXd in HER2 low/ultralow, but not HER2+ metastatic breast cancer. This presentation is scheduled for Wednesday, December 10, 2025, from 5:00 p.m. to 6:30 p.m. CDT (Presentation Number: PS2-08-18).
Treatment Sequencing in HR+ HER2- Metastatic Breast Cancer and Associated Real World Outcomes
The study investigates the impact of first-line and second-line therapy selections on real-world progression-free survival (rwPFS) and real-world overall survival (rwOS) in patients with HR+ HER2- mBC. The data suggests that CDK4/6i significantly outperforms taxane in first-line. Patients who received second-line CDK4/6i following first-line taxane had longer second-line rwPFS than those who received CDK4/6i first-line treatment. The findings suggest that taxane may cause sensitization to CDK4/6i, potentially conferring better survival outcomes in a subset of patients where first-line taxane is advised, or a potential advantage to chemo before CDK4/6i re-challenge. This presentation is scheduled for Wednesday, December 10, 2025, from 5:00 p.m. to 6:30 p.m. CDT (Presentation Number: PS2-04-11).
Real-World Second-Line Treatment Use and Clinical Outcomes in Patients With HR-Positive/HER2-Negative Metastatic Breast Cancer and an ESR1 Mutation
The study objective was to characterize real-world second-line treatment use and clinical outcomes (rwPFS and rwOS) in a metastatic breast cancer patient population with positive ESR1m test after first-line treatment with AI+CDK4/6i. Findings show that this cohort describes a complex subgroup of patients to treat, with rwPFS outcomes highlighting the need for more effective strategies that address resistance to AI+CDK4/6i and improve patient outcomes. Results from Flatiron Health EHR and Tempus both indicated consistent findings. This presentation is scheduled for Wednesday, December 10, 2025, from 5:00 p.m. to 6:30 p.m. CDT (Presentation Number: PS2-06-18).
Comparative Analysis of the Tumor Immune Microenvironment (TIME)
Tempus Lens was leveraged to assess the Tumor Immune Microenvironment (TIME) across metastatic sites of disease in HR+/HER2- breast cancer compared to TNBC, finding significant differences by site in both subtypes, with HR+/HER2- cancer being less immunogenic overall. Lung, pleura, and peritoneum metastases, along with breast and lymph nodes, showed the highest CD8+ T cell proportions, suggesting a subset of HR+/HER2- patients with these sites may potentially respond to Immune Checkpoint Inhibitor (ICI) therapy. This high variability of TIME profiles across metastatic sites warrants further study in prospective trials to guide patient selection for ICI. This presentation is scheduled for Thursday, December 11, 2025, from 12:30 p.m. to 2:00 p.m. CDT (Presentation Number: PS3-12-27).
The Molecular and Immune Landscape of HER2 Positive Breast Cancer
Tempus Lens was employed to evaluate the tumor immune microenvironment of HER2+ breast cancer, assessing immune cell infiltration, TMB, PD-L1 status, and HLA allele prevalence, to uncover biomarkers for treatment guidance. The research indicated a notable percentage of patients with localized and de novo metastatic disease displayed TMB high status and/or PD-L1 positivity. TMB-high and PD-L1 positive patients with de novo metastatic disease treated with first-line chemotherapy or anti-HER2 therapy had significantly worse real-world overall survival (rwOS), suggesting a potential therapeutic benefit of incorporating immunotherapy into the treatment paradigm, in both localized and metastatic disease settings. Furthermore, observed ethnic HLA polymorphisms in the cohort may contribute to differences in outcomes and could potentially guide the development of population-specific immunotherapeutic strategies. This presentation is scheduled for Thursday, December 11, 2025, from 5:00 p.m. to 6:30 p.m. CDT (Presentation Number: PS4-05-21).
Real-World Data (RWD) Outcome Analysis of ESR1 Mutation Emergence
The analysis focused on longitudinal molecular surveillance testing (xF) in HR+/HER2- mBC patients treated with AI+CDK4/6i, shedding light on the continuum of ESR1m emergence and patient outcomes from first-line and beyond outside of clinical trial data. Analyses show higher ESR1m incidence is associated with reduced survival regardless of line of therapy. This presentation is scheduled for Friday, December 12, 2025, from 12:30 p.m. to 2:00 p.m. CDT (Presentation Number: PS5-05-02).
Learn more about Tempus at SABCS 2025 here.
Source: Tempus AI, Inc.
