Quest Diagnostics Incorporated has secured approval from the New York State Department of Health for Haystack MRD, its circulating tumor DNA liquid biopsy test designed to identify residual or recurring disease in patients with solid tumors. The decision makes the laboratory-developed test available for patient testing across all 50 U.S. states and removes one of the final geographic barriers to broader clinical adoption.
The approval does not automatically establish Haystack MRD as a standard component of cancer care, but it gives Quest Diagnostics a nationwide commercial platform from which to build clinical evidence, physician confidence and payer support. The larger question is whether the company can convert technical sensitivity and regulatory progress into routine treatment decisions across colorectal, breast, ovarian, prostate and other solid tumor cancers.
Why does New York approval matter more than access to patients in a single state?
New York maintains one of the most demanding state-level oversight systems for laboratory-developed tests in the United States. Laboratories must submit technical information for review by the New York State Department of Health’s Clinical Laboratory Evaluation Program before eligible tests can be offered to patients in the state.
For Quest Diagnostics, the approval therefore carries significance beyond the size of the New York healthcare market. It provides an additional external assessment of Haystack MRD’s analytical framework and allows the company to describe the test as commercially accessible across the entire United States.
Haystack MRD had already been available to clinicians in 49 states and the District of Columbia since late 2024. New York represented the remaining major regulatory gap because Clinical Laboratory Improvement Amendments certification alone does not provide automatic access to the state.
Closing that gap creates a simpler national proposition for oncologists, health systems, clinical-trial sponsors and biopharmaceutical companies. Quest Diagnostics can now approach multistate healthcare networks without excluding New York patients or creating separate testing pathways based on location.
The nationwide footprint could be particularly important for longitudinal cancer monitoring. Minimal residual disease testing may require repeated blood collections over months or years, meaning geographical consistency and laboratory logistics can be nearly as important as the underlying assay.
How could Haystack MRD change cancer monitoring after surgery and treatment?
Minimal residual disease refers to small quantities of cancer that remain in the body after treatment but are too limited to be identified reliably through conventional imaging or clinical examination. These remaining cancer cells may release fragments of tumor-derived DNA into the bloodstream, creating a molecular signal that can potentially be detected before recurrence becomes visible.
Haystack MRD is designed to identify extremely low concentrations of circulating tumor DNA. A positive result may suggest that microscopic disease remains after surgery or that cancer is returning, while a negative result may provide additional evidence that treatment has eliminated detectable disease.
This information could eventually help oncologists address one of the most difficult questions in cancer care: which patients require additional therapy and which patients may safely avoid it.
After curative-intent surgery, physicians often make adjuvant treatment decisions using tumor stage, pathology, imaging findings and broader clinical risk factors. These measures are valuable but cannot always reveal whether residual cancer cells are still present.
A sufficiently accurate minimal residual disease test could add a direct molecular assessment. Patients with detectable circulating tumor DNA might be candidates for intensified treatment or closer surveillance, while patients without detectable disease might avoid chemotherapy that offers limited benefit but carries significant toxicity.
The clinical opportunity is therefore not merely earlier recurrence detection. The more consequential ambition is to use molecular information to guide treatment selection, treatment duration and surveillance intensity.
What makes a tumor-informed ctDNA test different from broader liquid biopsy approaches?
Haystack MRD uses a tumor-informed testing model. This generally involves analysing tissue from an individual patient’s tumour to identify cancer-specific genetic alterations and then designing a personalised blood-based assay that searches for those signals over time.
The personalised approach may improve specificity because the laboratory is not searching broadly for any abnormal DNA fragment. It is looking for alterations already identified in that patient’s tumour.
This design can be valuable when circulating tumour DNA levels are extremely low, as they often are after surgery or during early recurrence. Detecting a small molecular signal against a much larger background of normal cell-free DNA requires substantial analytical precision.
However, tumour-informed testing also creates operational complexity. The laboratory may require access to sufficient tumour tissue, successful sequencing of that tissue and time to design the patient-specific assay before monitoring can begin.
The practical value of Haystack MRD will therefore depend on more than laboratory sensitivity. Quest Diagnostics must demonstrate that the complete workflow, including tissue retrieval, assay development, blood collection, result reporting and repeat testing, can fit efficiently into real-world oncology practice.
Turnaround time may be especially important when physicians are deciding whether to initiate adjuvant treatment shortly after surgery. A highly accurate result that arrives after a treatment decision has already been made may have less clinical utility.
Why will prospective clinical evidence determine whether MRD testing changes treatment decisions?
The New York approval supports commercial access, but the broader adoption of Haystack MRD will depend on whether clinical studies demonstrate that acting on test results improves patient outcomes.
Quest Diagnostics has highlighted research involving patients with locally advanced mismatch repair-deficient solid tumours. In that study, Haystack MRD reportedly identified clinical complete response at a median of 1.4 months, compared with more than six months using imaging methods.
The result suggests that circulating tumour DNA may provide an earlier molecular indication of treatment response. That could be particularly valuable in non-operative treatment strategies where physicians need confidence that patients are responding adequately without immediate surgery.
However, earlier detection does not automatically prove improved survival or quality of life. A test may identify molecular recurrence sooner without establishing which intervention should follow or whether earlier intervention ultimately changes the course of the disease.
This distinction is central to the entire minimal residual disease market. Analytical sensitivity shows whether a test can find a signal. Clinical validity shows whether that signal is associated with recurrence or treatment response. Clinical utility requires evidence that using the result leads to a better decision or outcome.
Quest Diagnostics is therefore supporting studies across several treatment settings. Research with City of Hope is evaluating Haystack MRD in patients with breast, colorectal, ovarian and prostate cancers, including use before surgery, after surgery and during post-treatment surveillance.
The programme is expected to involve approximately 500 patients and thousands of longitudinal measurements across multiple clinical sites. Such studies could help determine where the test provides the strongest incremental value over pathology, imaging and existing monitoring methods.
Can Quest Diagnostics turn its national laboratory network into a commercial advantage?
Quest Diagnostics enters the minimal residual disease market with resources that many smaller molecular diagnostics companies do not possess. The company already serves a substantial portion of U.S. physicians, hospitals and adult patients and operates an established system for specimen collection, transportation, laboratory processing and electronic result delivery.
This infrastructure could reduce some of the friction associated with introducing a specialised oncology assay. Physicians already familiar with Quest Diagnostics may find it easier to order Haystack MRD through existing channels than to establish new arrangements with an unfamiliar laboratory.
The company can also integrate minimal residual disease testing with a broader oncology portfolio that includes pathology, genomic profiling and other diagnostic services. Over time, this could allow Quest Diagnostics to position itself as a more comprehensive partner across the cancer-care pathway.
Haystack Oncology also works with pharmaceutical and biotechnology companies conducting clinical trials. Circulating tumour DNA measurements can potentially help drug developers assess treatment response, identify high-risk participants, stratify trial populations and establish molecular endpoints.
The biopharmaceutical opportunity could be strategically important because it may generate revenue while broader clinical reimbursement develops. Clinical-trial partnerships may also create datasets that support additional tumour types, treatment settings and regulatory submissions.
Quest Diagnostics acquired Haystack Oncology in 2023 as part of its effort to strengthen its position in precision oncology. The New York approval represents another step in converting that acquisition from a specialised scientific capability into a nationally distributed clinical product.
How does FDA Breakthrough Device Designation strengthen the longer-term strategy?
Haystack MRD received FDA Breakthrough Device Designation in 2025 for identifying minimal residual disease-positive patients with stage II colorectal cancer following curative-intent surgery who may benefit from adjuvant therapy.
The designation does not represent FDA marketing approval. It is intended to support more intensive communication with the agency and potentially accelerate the development and review of devices addressing serious conditions where existing alternatives may be limited.
The distinction between the commercially available laboratory-developed test and a potential FDA-authorised version is important. Quest Diagnostics can currently offer Haystack MRD through its certified laboratory framework, but an FDA-reviewed product could provide a stronger foundation for defined clinical claims, reimbursement discussions and integration into treatment guidelines.
Stage II colorectal cancer is an important initial indication because treatment decisions can be particularly uncertain. Many patients are cured through surgery alone, while a smaller group has residual disease and may benefit from chemotherapy.
A reliable molecular test could help separate those groups more precisely. This could reduce unnecessary treatment for lower-risk patients while identifying individuals whose cancer may return despite apparently successful surgery.
The FDA pathway could also serve as a model for future submissions in additional cancers. However, each tumour type and clinical setting may require separate evidence because tumour biology, DNA shedding and treatment pathways vary considerably.
What could prevent nationwide availability from translating into routine clinical adoption?
Access is only one requirement for commercial success. Reimbursement, clinical guidelines, physician education, evidence quality and workflow integration will determine whether Haystack MRD becomes widely used.
Payers may require proof that the test changes patient management and reduces downstream costs before offering broad coverage. Earlier recurrence detection could theoretically lower treatment costs by enabling faster intervention, but repeated testing across large patient populations could also increase near-term diagnostic spending.
Negative results must also be interpreted carefully. The absence of detectable circulating tumour DNA does not necessarily prove that no cancer remains. Some tumours release limited DNA into the bloodstream, and testing performance may vary according to tumour type, disease burden, treatment timing and sample quality.
Positive results create a different challenge. Physicians need evidence-based guidance on what to do when molecular recurrence appears before conventional imaging identifies a tumour. Immediate treatment could help some patients, but it could also expose others to therapy without sufficient proof of benefit.
False reassurance, unnecessary anxiety and treatment based on uncertain molecular findings remain important risks. Minimal residual disease testing is therefore more likely to complement imaging, pathology and clinical assessment than to replace them in the foreseeable future.
Standardisation will also matter. Competing tests may use different sequencing methods, detection thresholds and patient-specific designs. Results from one platform may not be directly comparable with results from another, complicating guideline development and physician interpretation.
What does the recent Quest Diagnostics share-price performance suggest about investor sentiment?
Quest Diagnostics shares closed at approximately $206.24 on June 25, leaving the stock less than four percent below its 52-week high of $213.50. The shares had gained approximately 5.76 percent over five trading days and about 5.82 percent over one month, indicating constructive near-term sentiment around the broader business.
The Haystack MRD approval is unlikely to transform Quest Diagnostics’ earnings by itself in the immediate period. The company remains a large and diversified laboratory-services provider, meaning the financial contribution from one advanced oncology test may initially be modest relative to its total operations.
However, the approval supports a strategically important growth narrative. Quest Diagnostics has identified advanced diagnostics, including oncology, brain health, cardiometabolic testing, women’s health and autoimmune disorders, as areas expected to generate faster growth than traditional routine laboratory services.
Investor attention is therefore likely to focus on whether Haystack MRD produces measurable test-volume growth, favourable reimbursement decisions and evidence of adoption across major cancer centres. Partnerships with pharmaceutical companies and integration into clinical trials may provide earlier indicators of commercial traction than standalone revenue disclosure.
Sentiment appears positive, but the valuation increasingly requires Quest Diagnostics to demonstrate that advanced diagnostics can become a meaningful growth engine rather than remaining a collection of scientifically promising but relatively small products.
What should clinicians and the diagnostics industry watch after the New York decision?
The next phase will centre on evidence, reimbursement and regulatory progression. Additional prospective studies should clarify whether Haystack MRD can guide chemotherapy decisions, support non-operative management and improve surveillance across different solid tumours.
Quest Diagnostics will also need to show how efficiently the test can be delivered through routine clinical workflows. Nationwide availability creates the opportunity, but physician ordering patterns, turnaround times and repeat-testing compliance will reveal whether the service is practical at scale.
Progress toward an FDA-reviewed indication in stage II colorectal cancer will be closely watched. A successful regulatory outcome could strengthen clinical confidence and create a clearer pathway for payer coverage.
The competitive landscape is also likely to intensify as diagnostics companies pursue both tumour-informed and tumour-naive minimal residual disease strategies. Companies will compete not only on sensitivity but also on clinical evidence, turnaround time, reimbursement, physician access and pharmaceutical partnerships.
For Quest Diagnostics, the New York approval turns Haystack MRD into a genuinely national offering. Whether it becomes a nationally adopted oncology tool will depend on the company’s ability to prove that earlier molecular information leads to better and more confident treatment decisions.
