On December 5, 2025 Guardant Health, Inc. (Nasdaq: GH), a leading precision oncology company, reported it will present a total of 14 abstracts with its research collaborators from multiple studies demonstrating the value of its tissue-free liquid biopsy tests at the 2025 San Antonio Breast Cancer Symposium (SABCS), taking place Dec. 9–12, 2025.

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Oral presentations will highlight results generated with Guardant Reveal, the company’s tissue-free test for detecting minimal residual disease (MRD) and Guardant360 Liquid, the company’s comprehensive multiomic profiling test, both leveraging Guardant’s proprietary epigenomic technology powered by the Guardant Infinity Smart Platform. Collectively, these studies demonstrate how blood-based testing can uncover risk, guide treatment selection, and influence long-term patient management across the breast cancer continuum, from early-stage disease through metastatic settings.

Guardant’s MRD presentations reinforce the value of tissue-free circulating tumor DNA (ctDNA) testing for both neoadjuvant treatment response assessment and post-treatment surveillance in early-stage breast cancer. In a retrospective analysis of HER2-positive patients, ctDNA measured with Guardant Reveal demonstrated strong prognostic significance in the neoadjuvant setting, showing a correlation with pathological complete response and three-year invasive disease-free survival. In an independent study of triple-negative breast cancer patients, Guardant Reveal accurately predicted relapse risk and detected ctDNA more frequently and earlier than orthogonal methods.

Together, these findings demonstrate the validity of Guardant Reveal as a reliable approach for ctDNA detection and monitoring in both neoadjuvant and surveillance settings.

"Breast cancer care increasingly depends on understanding tumor biology at every stage of disease, and Guardant’s data continues to reaffirm the growing value of multiomic liquid biopsy as a powerful, non-invasive tool to equip providers with the data necessary to tailor therapy and treatment," said Dr. Craig Eagle, Chief Medical Officer at Guardant Health. "We look forward to sharing our findings demonstrating the power of blood in helping provide clinicians with deeper clarity and more confident decision-making for their patients."

Other data highlights to be presented include:

Data showcasing the clinical utility of Guardant Reveal in predicting outcomes in patients with early-stage HER2-positive breast cancer. In this analysis, early ctDNA clearance throughout treatment was linked to better outcomes, underscoring ctDNA as a sensitive marker of treatment response and highlighting the value of tissue-free testing for real-time response monitoring.
Data supporting the clinical value potential of non-invasive, methylation-based, continuous breast cancer subtype monitoring by Guardant360 Liquid to uncover tumor evolution and heterogeneity that may guide more precise treatment decisions. In this analysis, Guardant360 Liquid showed agreement to tissue-based monitoring and replicated previously reported accuracy.
Data showcasing Guardant360 Liquid methylation-based breast cancer subtyping feature as a noninvasive liquid tool to dynamically reassess ER, HER2 and triple negative status in patients who are resistant to ER therapy but don’t carry an ESR1 mutation. In this study, Guardant360 Liquid predicted real-world outcomes in previously AI-treated patients receiving subsequent lines of therapy.
Guardant-Led Research at SABCS 2025

Presentation

Title

Time / Location

Wednesday, December 10

PD2-09

Molecular Evolution in Early and Late-Stage Tumors

7:00 – 8:30am CST / 301 ABC

GS1-07

Circulating tumor DNA (ctDNA) in human epidermal growth factor receptor

9:30am – 12:00pm / Hall 1

PS1-12-05

Liquid biopsy–based molecular profiling using GUARDANT360 CDx at progression on CDK4/6i+ET: findings from the AGO-B CAPTOR study

12:30pm – 2:00pm / Exhibit Hall

PS1-11-09

Real-world prevalence of estrogen receptor (ER) 1 mutations (ESR1m) among patients with ER+/ human epidermal growth factor receptor 2 (HER2)− metastatic breast cancer (MBC) after first-line (1L) treatment with endocrine therapy (ET) and/or cyclin dependent kinase 4/6 inhibitors (CDK4/6i)

12:30pm – 2:00pm / Exhibit Hall

RF3-05

Tissue-free circulating tumor DNA detection in patients with early triple negative breast cancer from the c-TRAK-TN trial

12:30pm – 2:00pm / Exhibit Hall

PS2-07-02

Tissue-free epigenomic circulating tumor DNA (ctDNA) analysis pre- and post-surgery in early breast cancer: clinical features and prognostic utility

4:30pm – 5:30pm / Stars at Night

PS2-07-18

Prognostic effects of methylation-based HR and HER2 assessments by liquid biopsy in ESR1 mutation negative advanced breast cancer

4:30pm – 5:30pm / Stars at Night

PS2-07-16

Clinicogenomic characterization and ctDNA detection of ESR1 fusion positive metastatic breast cancer

5:00pm – 6:30pm / Exhibit Hall

PS2-09-21

Real-world clinical outcomes and genomic insights for patients with PIK3CA-mutant metastatic breast cancer following progression on CDK4/6 inhibitor therapy

5:00pm – 6:30pm / Exhibit Hall

PS2-08-17

Prevalence and clinical significance of exon 6 ESR1 gene fusions in advanced breast cancer after disease progression on aromatase inhibitors

5:00pm – 6:30pm / Exhibit Hall

PS2-10-19

Circulating tumor DNA (ctDNA) as a strong prognostic biomarker of minimal residual disease (MRD) using a tissue-free, epigenomic assay in early-stage breast cancer.

5:00pm – 6:30pm / Exhibit Hall

Thursday, December 11

PD9-03

Comprehensive genomic profiling and clinically targetable mutations of metastatic invasive lobular and no special type breast cancer

7:00am – 8:30am / Hemisfair Ballroom

PS4-01-11

Exploration of racial differences in variants of uncertain significance (VUS), ESR1 and PIK3CA mutation frequency, matched therapy use, and outcomes in metastatic breast cancer (mBC)

7:00am – 8:30am / Hemisfair Ballroom

PS4-02-10

Agreement of cell-free DNA methylation-based molecular breast subtyping and tissue subtyping in hormone receptor positive metastatic breast cancer: a clinical cohort analysis

5:00pm – 6:30pm / Exhibit Hall

The full abstracts for Guardant Health and a list of all abstracts being presented at SABCS 2025 can be found on the SABCS website.

For information and updates from the conference, visit booth #942 and follow Guardant Health on LinkedIn, X (Twitter) and Facebook.

(Press release, Guardant Health, DEC 5, 2025, View Source [SID1234661180])