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Transforming the management of cancer with personalized testing

Signatera is a personalized, tumor-informed assay optimized to detect circulating tumor DNA (ctDNA) for molecular residual disease (MRD) assessment and recurrence monitoring for patients previously diagnosed with cancer, with broad utility for cancer management.

Signatera Frequently Asked Questions

What is Signatera and what does it test for?

Signatera is a personalized molecular test for the detection of circulating tumor DNA (ctDNA) in the blood of patients previously diagnosed with cancer. This testing can be used to detect minimal, or molecular, residual disease (MRD) following surgery, to monitor response to cancer treatment, or detect cancer recurrence following a period of remission.

How is Signatera different from current biomarker tests?

Signatera is not a traditional oncology test. It does not focus on well-characterized mutations, oncogenes or hotspots like most tests. Instead, Signatera utilizes a WES-based, tumor-informed approach to create 16 bespoke assays that target specific, and generally unique, mutations found in your patient’s tumor, but absent in their germline DNA.

How accurate is Signatera?

Signatera is an extremely sensitive and specific test, due to the fact that it is customized specifically from your patient’s tumor. The specificity is >99.5%, and we are able to control for false positives that would result from the detection of natural background variants that occur in the patient’s DNA. The sensitivity is also remarkable as Signatera can detect a single ctDNA molecule from 10mL of plasma. In fact, our clinical studies have shown that over 50% of the time, Signatera will first detect the presence of ctDNA at a variant allele frequency (VAF) between 0.01-0.1%, far superior to our competitors who have a lower limit of detection equivalent to VAF between 0.1-1%.

What do the results mean?

A Signatera positive result indicates the presence of circulating tumor DNA (ctDNA) in your patient’s blood and by extension, the presence of tumor in the patient’s body. Positive results are highly correlated with inferior prognosis (e.g. reduced disease-free survival). The numerical value is associated with overall tumor burden for each patient, but only on a relative basis compared to previous Signatera results. In other words, the significance is in the trend; is the amount of ctDNA detected increasing, decreasing, stable from one time point to another. We have not proven that a certain quantity of ctDNA detected equates to a certain outcome, prognosis, tumor-burden or disease state; this likely varies from person to person. However, increases in MTM/mL for a given patient are associated with an increase in tumor burden for that patient and visa versa.


A negative result indicates that ctDNA was not detected in your patient’s blood at a given timepoint. This does not mean that the patient is in remission (absence of cancer that has been treated), rather it could mean that the tumor burden that remains is at such low levels that it is not detected in the blood. For this reason, Signatera is best utilized when ordered repetitively, so that ctDNA detection and/or ctDNA levels can be assessed in a longitudinal manner. The longer the patient remains ctDNA negative, the more likely that individual will not relapse.

What is needed to start Signatera?

Talk to your oncologists about ordering Signatera. Your oncologists will need to complete a requisition form requesting that Signatera be performed. After that, once we have received your initial blood samples our team will work with you pathologist to obtain tissue samples. If tissue is not available, Signatera cannot be performed.

What type of samples are needed?

For initial testing we require one FFPE block with >25mm^2 of surface area (tissue block) and one H&E slide (preferred) OR 6-10 (10 microns) or 12-20 (5 microns) slides and one H&E slide (10 micron thickness). We also require two 10mL streck tubes and one 6mL EDTA tube. For subsequent testing, we require two 10mL Streck tubes only.

How long does it take to get my results?

The first time the Signatera test is ordered, it will take two weeks for tumor-tissue sequencing results to become available from the date the tumor tissue is received. Then, it will take another one week for your personalized test design and for your physician to receive the first Signatera test result. After the test has been designed, your Signatera test results will become available to your physician one to two weeks after your blood sample is received by the Natera laboratory.

How much will it cost patients?

If a patient is uninsured or concerned about their ability to pay for testing, they can complete an online application or contact one of our Patient Coordinators at

How does Signatera billing work for recurring orders versus a single test order?

Testing which occurs within the first 6 months after surgery is considered adjuvant testing. This is offered as a bundled service or recurring testing to include the initial whole exome sequencing (WES) + up to 4 tests.

How does Signatera billing work in the surveillance setting?

When a patient is greater than 6-months out in their postoperative treatment journey, they are in the surveillance setting. These patients have a history of cancer but no evidence of disease or disease recurrence. Signatera ordered in the surveillance setting is recommended at the same cadence as CEA, as directed by the treating physician. If a patient is ctDNA positive they cannot qualify as a surveillance patient as this is considered ‘active’ cancer.

Are other stages or other types of cancer covered by Medicare?

Medicare patients are fully covered under the following scenarios:

  • Stage II/III colorectal cancer for Signatra testing
  • With solid tumors on immuno-therapy for Signatera testing
  • With stages III and IV solid tumors for Altera testing

If Signatera is still requested for other cancer types which fall outside of the Medicare stated coverage, an ABN will be required.

Can a patient cancel an order?

Patients can cancel testing anytime up until the sample is received in the lab.

What happens if coverage is denied? How does the appeal process work?

Natera Patient Coordinators will work with the patient’s insurance provider to file appeals and pursue coverage on the patient’s behalf.

Does Natera reach out to patients to explain their potential out of pocket prior to processing the initial sample?

A Patient Coordinator will reach out and contact the patient regarding coverage and potential out of pockets costs.

Who can I contact if I have any additional billing questions?

For any questions or to request financial assistance, please contact Natera’s Patient Coordinators:| Phone: 650.489.9050| Fax: 650.412.1962

Where can I get my blood drawn for Signatera?

You can get your blood drawn at various locations that offer blood draw services. We also offer a mobile phlebotomy service at no additional cost to you.
Contact 650.489.9050 to request a home blood draw or go to our online tool to request a mobile draw or find a Natera approved lab location.

Is Signatera right for you?

We’re here to help you find out.