Independent ctDNA Interpretation
Your Signatera came back positive. Here is what to do next.
A positive result is one of the most stressful moments in cancer care. It is also one of the most important windows for action. MITOTICS® helps you understand exactly what your result means, what it does not mean, and which questions to bring to your oncologist this week.
15 minutes, free, no obligation. No records or payment needed.
What a positive Signatera result actually tells you
Signatera is a personalized, tumor-informed blood test. It is built from the sequencing of your own tumor and looks for fragments of that tumor's DNA circulating in your blood, known as circulating tumor DNA (ctDNA).
A positive result means that tumor DNA was detected. In many patients, this signal appears before anything is visible on a scan. That lead time is the reason the result matters, and the reason how you respond to it matters.
A positive result does not, on its own, tell you where disease is located, how quickly it is changing, or which treatment is right for you. Those answers come from putting the result in context.
The details that change the interpretation
Two people with a positive result can be in very different situations. The factors that matter include:
- The level reported (MTM/mL) and whether it is rising, stable, or falling across tests
- Whether this is a first positive or part of an established trend
- Timing relative to surgery, chemotherapy, radiation, or other treatment
- Your cancer type, stage, and original tumor biology
- What recent imaging shows, and what kind of imaging was done
- Whether your tumor carries actionable biomarkers that open specific treatment or trial options
This is the work MITOTICS® does every day: reading the result alongside your full record so the next decision rests on the whole picture.
Situations we help patients navigate
"My first positive came after years of negative results."
"My scans are clear, but my Signatera is positive."
"My oncologist wants to wait and repeat the test."
"My MTM/mL went up between two tests and I want to know what that means."
"I want to know whether a clinical trial is an option at this stage."
If one of these sounds like you, a free 15-minute call is the right first step.
Independent scientific interpretation, alongside your care team
MITOTICS® is an independent precision oncology advisory practice led by Kim Lockheimer, PhD, a molecular oncology scientist with deep expertise in ctDNA, minimal residual disease testing, and genomic profiling platforms including Signatera, FoundationOne CDx, Tempus, Guardant360, and Caris.
We do not replace your oncologist. We help you walk into your next appointment informed, organized, and ready to ask the questions that move your care forward.
What you receive:
- A clear explanation of your result in plain language
- A review of your ctDNA trend, imaging, pathology, and genomic reports together
- The specific questions to raise with your oncologist
- Guidance on whether further testing, closer monitoring, or a clinical trial search makes sense for your situation
How the free call works
- Request a free 15-minute call online, or call or text.
- Tell Kim briefly what your Signatera result shows and what you are worried about. No records or payment needed.
- On the call, Kim explains which review, if any, would help and what it costs. If none would, she will tell you.
- If you choose to go ahead, you receive instructions for securely sharing your records.
As much as we'd like to help everyone, we take on a limited number of cases so each patient gets our utmost attention.
Frequently asked questions
Does a positive Signatera result mean my cancer is back?
It means tumor DNA was detected in your blood. Many patients with a positive result go on to show recurrence on imaging, but the meaning depends on the level, the trend, your cancer type, and your treatment history. That is the context we help you understand.
My scans are clear. Which result do I believe?
Both can be accurate at the same time. ctDNA can detect disease at levels too small for imaging to see. A clear scan with a positive ctDNA result is a common and important situation, and it calls for a thoughtful plan rather than waiting without one.
Should I repeat the test before doing anything?
Repeat testing is often reasonable, especially after a first low-level positive. The right timing, and what to do in the meantime, depends on your situation. We help you and your oncologist think that through.
What does the MTM/mL number mean?
MTM/mL stands for mean tumor molecules per milliliter of plasma. It is a measure of how much tumor DNA was found. The direction of change across tests is often as informative as any single value.
Do you replace my oncologist?
No. MITOTICS® provides independent scientific interpretation and advocacy. All treatment decisions remain with you and your medical team.
Can you help if I live outside California?
Yes. MITOTICS® works with patients and families nationwide by telehealth.
Are you affiliated with Natera?
No. MITOTICS® is fully independent and has no financial relationship with any testing company. Our only obligation is to you.
You do not have to sort this out alone.
Get clear, independent answers about your Signatera result from a molecular oncology scientist, before your next appointment.
Questions first? Call (888) 498-8650
MITOTICS® provides independent scientific interpretation and patient advocacy services. MITOTICS® does not practice medicine, diagnose disease, or prescribe treatment. Signatera is a trademark of Natera, Inc. MITOTICS® is not affiliated with or endorsed by Natera, Inc.