Tumor-Informed ctDNA Test Shows Utility Across Gastrointestinal and Gynecologic Cancers

Natera announced new data on Signatera, its tumor-informed circulating tumor DNA test, that were presented in four oral presentations at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting. The presentations covered gastrointestinal and gynecologic cancers and marked Natera’s first participation at the meeting. Across the studies, Signatera was evaluated for treatment response monitoring and risk stratification across different tumor types and treatment settings.

Two presentations from Memorial Sloan Kettering Cancer Center evaluated Signatera in cancers where organ preservation is an important treatment goal. In locally advanced rectal cancer (LARC), a real-world study found that Signatera detected every case of local tumor growth or recurrence, corresponding to 100% sensitivity, while achieving 97% specificity following neoadjuvant treatment.

Image: Signatera analyzes circulating tumor DNA (ctDNA) to assess molecular residual disease (MRD) (Photo courtesy of Natera)

In anal squamous cell carcinoma (ASCC), Signatera positivity after definitive chemoradiation therapy identified patients at higher risk of progression. Patients with a positive result had an 18-month progression-free survival rate of 8% and an overall survival rate of 73%. By comparison, patients who remained Signatera-negative after chemoradiation therapy had an 18-month progression-free survival rate of 97%.

Two additional presentations evaluated Signatera in gynecologic cancers. In vulvovaginal cancer, Signatera status by the end of treatment identified patients with significantly improved progression-free survival. Signatera positivity also preceded radiographic recurrence in all patients who experienced recurrence, corresponding to 100% sensitivity, with a median lead time of 117 days.

In locally advanced cervical cancer treated with chemoradiation, Signatera positivity at the midpoint of treatment identified a patient who subsequently experienced recurrence nine months later. All patients who were Signatera-negative at the midpoint remained disease-free. Together, the presentations provided additional evidence for the potential role of Signatera monitoring in treatment response assessment and risk stratification in radiation oncology.

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Memorial Sloan Kettering Cancer Center