Natera, Inc. (NASDAQ: NTRA) announced the publication of new data in JAMA Oncology showing its Signatera molecular residual disease (MRD) test predicted overall survival benefit from adjuvant chemotherapy in patients with resected colorectal liver metastases.

The study, drawn from 298 patients in the GALAXY trial — the prospective, observational arm of CIRCULATE-Japan — found that MRD-positive patients who received adjuvant chemotherapy after surgery without prior neoadjuvant chemotherapy had significantly improved outcomes compared to those under observation alone. The 48-month overall survival rate was 65.3% versus 32.9%, with an adjusted hazard ratio of 0.27 (P=0.03). MRD-negative patients showed no significant survival benefit from adjuvant chemotherapy.

Post-surgical MRD positivity, measured two to ten weeks after surgery, was associated with significantly worse disease-free survival and overall survival regardless of whether patients had received neoadjuvant chemotherapy beforehand. Among those who had not received neoadjuvant chemotherapy, the overall survival hazard ratio for MRD-positive patients was 9.13 (P<0.0001).

According to the press release, this represents the first dataset in a large cohort to show MRD test prediction of overall survival benefit from adjuvant chemotherapy in this patient population. The findings were also presented as an oral presentation at the 2026 European Society for Medical Oncology Gastrointestinal Congress.

"For patients with colorectal liver metastases, the benefit of adjuvant chemotherapy after curative-intent surgery has remained uncertain," said Kozo Kataoka, M.D., Ph.D., of Hyogo Medical University and senior author of the study. "This is the largest analysis to show that post-surgical MRD status may help identify which patients benefit from adjuvant chemotherapy in patients who underwent upfront surgery."

The median follow-up period for the study was 43 months. The liver is the most common site of distant metastasis in colorectal cancer and is a major cause of cancer-related mortality.