Myriad Genetics (NASDAQ: MYGN) announced the expanded availability of its Precise MRD test to patients with breast, colorectal, and renal cancers, according to a company press release. More than 6 million people in the U.S. are living with these cancers, according to the National Cancer Institute.

Precise MRD is a whole-genome sequencing-based assay that tracks up to 1,000 patient-specific variants to measure circulating tumor DNA (ctDNA). The test is designed for use at multiple points in cancer care, including neoadjuvant monitoring, post-surgical assessment, and long-term surveillance.

Alongside the expansion, Myriad published results from the prospective, multi-center MONITOR-Breast study in Future Oncology. The study evaluated 154 patients with Stage I–III breast cancer across all molecular subtypes, analyzing 949 plasma samples collected longitudinally during treatment.

Key findings from the study included ctDNA detection in 93% of patients at baseline, with 20% detected at ultrasensitive levels below 100 parts per million. Precise MRD predicted pathological complete response with 100% specificity. Patients who were ctDNA positive at the end of neoadjuvant therapy were 47 times more likely to remain ctDNA positive after surgery.

The study also found that 78% of patients showed sustained ctDNA clearance and were more likely to achieve pathological complete response, while 22% showed persistent or intermittent positivity. Longitudinal testing identified 44% more patients at risk for residual disease compared to testing at a single post-treatment timepoint.

"MONITOR-Breast highlights the strength of a whole-genome, tumor-informed approach to MRD detection," said Dale Muzzey, Chief Scientific Officer at Myriad Genetics. "The ability to identify additional at-risk patients through frequent sampling, beyond a single timepoint assessment, demonstrates the importance of molecular monitoring in improving risk stratification and guiding clinical decision-making."