SignateraTM MRD Identifies Breast Cancer Patients Who Can Forgo Surgery

Key Terms

molecular residual disease medical

Molecular residual disease is the tiny amount of cancer that can remain in the body after treatment and is detectable only by sensitive tests that find cancer DNA or other molecular traces. It matters to investors because these measurements can predict relapse, guide whether additional therapy is needed, and shape the market for diagnostics and drugs—much like finding embers after a fire helps decide if more firefighting is required.

mrd medical

MRD stands for minimal residual disease, the tiny number of cancer cells that can remain in the body after treatment and that may not show up on routine scans. Detecting MRD is like finding a few seeds left in a garden after clearing: it helps doctors predict the chance of relapse and measure how effective a therapy is, which investors watch because MRD results can influence clinical trial success, regulatory decisions, and a drug’s market potential.

er+/her2- breast cancer medical

A type of breast cancer whose tumor cells have receptors that feed on the hormone estrogen (ER+) but lack excess HER2 protein (HER2-). Knowing this subtype is like reading a lock on the tumor: it signals that hormone-blocking treatments are likely to work while HER2-targeted drugs won’t, which matters to investors because it shapes which therapies, clinical trials, and drug revenues are relevant and how a company’s pipeline or market opportunity may perform.

primary endocrine therapy medical

Primary endocrine therapy is the use of hormone-blocking medications as the first and main treatment for hormone-driven cancers instead of immediate surgery or radiation. Think of it like turning off a faucet that feeds a tumor so it shrinks or stops growing. Investors care because its use determines demand for hormone therapies, shapes clinical trial design and regulatory decisions, and affects long-term market size and reimbursement for those drugs.

pet medical

Positron emission tomography (PET) is a medical imaging test that creates a live map of how organs and tissues are working by tracking a tiny, safe amount of radioactive tracer inside the body. For investors, PET matters because it’s often used in clinical trials and diagnosis to show whether a drug or treatment is affecting disease — think of it as a performance meter that can speed regulatory decisions, change market forecasts, and affect a product’s commercial value.

circulating-tumor dna medical

Circulating-tumor DNA is small pieces of genetic material that cancer cells release into the bloodstream and can be detected with a blood test. For investors, it matters because these tests can offer earlier, less invasive detection of cancer and real-time tracking of how a tumor responds to treatment, creating potential markets for diagnostics and therapies; think of it as reading smoke in the blood to find and monitor a hidden fire.

ctdna medical

Circulating tumor DNA (ctDNA) is tiny fragments of genetic material shed by cancer cells into the bloodstream, like breadcrumbs that can reveal a tumor’s presence and genetic makeup without needing a biopsy. For investors, ctDNA matters because tests and technologies that detect and analyze these fragments can speed diagnosis, track treatment response, and signal relapse, creating commercial opportunities in diagnostics, personalized therapies, and monitoring services.

cell-free dna medical

Fragments of DNA that float freely in the bloodstream after being released by dying or damaged cells, like puzzle pieces carried downstream that hint at what’s happening upstream. Investors care because measuring these fragments enables non‑invasive tests — for example to detect cancer, monitor treatment response, check pregnancy health, or spot organ rejection — so advances, approvals, or reimbursement changes can quickly affect companies that develop the tests and related technologies.

Prospective study published in Clinical Cancer Research shows that women >70 who tested Signatera MRD-negative could avoid surgery and remain progression-free

AUSTIN, Texas--(BUSINESS WIRE)-- Natera, Inc. (NASDAQ: NTRA), a global leader in cell-free DNA and precision medicine, today announced a publication in Clinical Cancer Research showing that Signatera was able to identify older women with early-stage ER+/HER2- breast cancer who can be managed with primary endocrine therapy (pET), without surgery.

While pET can be an alternative to surgery for patients with early breast cancer, tools for risk stratification and monitoring have been limited. This prospective study enrolled 43 women, aged 70 and older, with stage 1-3 ER+/HER2- breast cancer who all elected to forgo surgery and receive pET. Patients were tested with Signatera at baseline (pre-treatment), and then every 3-6 months alongside standard imaging and physician assessment. Key results included:

• Pre-treatment (baseline) molecular residual disease (MRD) assessment identified that 68% of patients (23/34) were MRD-negative, among whom zero experienced progression (100% negative predictive value at baseline).
• Among the 11 patients who tested baseline MRD-positive, 64% (7/11) cleared their circulating-tumor DNA (ctDNA) after 6 months of pET, where all 7 remained free of distant progression, and 1 out of 7 experienced locoregional progression that was detected by Signatera in advance of imaging.
• Tumor progression occurred in 5 patients, all of whom tested MRD-positive in advance of imaging (longitudinal sensitivity of 100%).
• Over 80% of patients reported that Signatera helped inform their treatment decisions without increased anxiety.

“Treatment decisions for older patients with breast cancer often require balancing disease control with quality of life, other medical problems and patient preference,” said Priscilla F. McAuliffe, M.D., Ph.D., lead author of the study and a surgical oncologist at the University of Pittsburgh. “The findings from this study suggest ctDNA monitoring with Signatera could help identify patients for whom non-surgical approaches for their breast cancer treatment may be appropriate.”

“This study highlights the role of Signatera as a critical molecular monitoring tool for patients with breast cancer who defer surgery,” said Angel Rodriguez, M.D., senior medical director of oncology at Natera. “By providing an early signal of disease progression that aligns with imaging, Signatera may help physicians monitor treatment response and make more informed care decisions for older patients.”

About Natera

Natera™ is a global leader in cell-free DNA and precision medicine, dedicated to oncology, women’s health, and organ health. We aim to make personalized genetic testing and diagnostics part of the standard-of-care to protect health and inform earlier, more targeted interventions that help lead to longer, healthier lives. Natera’s tests are supported by more than 400 peer-reviewed publications that demonstrate excellent performance. Natera operates ISO 13485-certified and CAP-accredited laboratories certified under the Clinical Laboratory Improvement Amendments (CLIA) in Austin, Texas, and San Carlos, California, and through Foresight Diagnostics, its subsidiary, operates an ISO 27001-certified and CAP-accredited laboratory certified under CLIA in Boulder, Colorado. For more information, visit www.natera.com.

Forward-Looking Statements

All statements other than statements of historical facts contained in this press release are forward-looking statements and are not a representation that Natera’s plans, estimates, or expectations will be achieved. These forward-looking statements represent Natera’s expectations as of the date of this press release, and Natera disclaims any obligation to update the forward-looking statements. These forward-looking statements are subject to known and unknown risks and uncertainties that may cause actual results to differ materially, including with respect to whether the results of clinical or other studies will support the use of our product offerings, the impact of results of such studies, our expectations of the reliability, accuracy, and performance of our tests, or of the benefits of our tests and product offerings to patients, providers, and payers. Additional risks and uncertainties are discussed in greater detail in "Risk Factors" in Natera’s recent filings on Forms 10-K and 10-Q, and in other filings Natera makes with the SEC from time to time. These documents are available at www.natera.com/investors and www.sec.gov.

View source version on businesswire.com: https://www.businesswire.com/news/home/20260331738825/en/

Investor Relations: Mike Brophy, CFO, Natera, Inc., investor@natera.com
Media: Lesley Bogdanow, VP of Corporate Communications, Natera, Inc., pr@natera.com

Source: Natera, Inc.