Quest Diagnostics (NYSE: DGX) announced that the New York State Department of Health's Clinical Laboratory Evaluation Program has approved its Haystack MRD test, a circulating tumor DNA liquid biopsy test used to identify residual or recurring disease in patients with solid tumor cancers.

The approval makes Haystack MRD available for patient testing in all 50 U.S. states. The test had been available for clinician ordering since late 2024 in 49 states and the District of Columbia. New York requires formal technical review and approval of laboratory-developed tests before they may be offered to patients in the state.

Haystack MRD is developed by Haystack Oncology, a wholly owned subsidiary of Quest Diagnostics. The test is tumor-informed and detects low levels of ctDNA to identify residual or recurrent disease. The FDA granted the test Breakthrough Device Designation in 2025 for use in Stage II colorectal cancer.

The test was used in a study of non-operative management of patients with locally advanced mismatch repair-deficient solid tumors, led by Dr. Andrea Cercek and colleagues at Memorial Sloan Kettering Cancer Center and published in The New England Journal of Medicine in May 2025. In that study, ctDNA testing using Haystack MRD was described as a "reliable liquid biopsy surrogate" that identified clinical complete response at a median of 1.4 months, compared to more than six months using imaging methods.

"In our study of non-operative management for dMMR solid tumors, the use of MRD testing provided additional molecular information that complemented traditional assessments such as imaging and endoscopy," said Dr. Cercek. "For patients who may avoid surgery, having multiple tools to evaluate treatment response and monitor for recurrence is important."

Haystack MRD is also available for clinical trials as an investigational device in laboratories in Baltimore, Maryland; Hamburg, Germany; and Helsinki, Finland.