Signatera Test. Is it truly helpful and worthwhile?

My oncologist says if Signatera test shows cancer cells in blood, it's not clear what, if anything, to do about it.
Is this true for all or just for people with stage 1, grade 2-3?
ps I'm taking anastrozole & Kisqali (ribociclib), had surgery and radiation 8 months ago.

I see it as a tool to see if treatment is working. If levels start to go up then a closer eye needs to be kept on your cancer. My counts have decreased to zero. Praying they stay that way.

I'm a retired biopharma & diagnostics medical director. I worked on the development & validation of a number of ctDNA/cfDNA assays that are used to monitor patients' responses to therapies and minimal residual disease burden. The Signatera assay, developed by Natera, and offered by FoundationOne, has very good clinical specificity, sensitivity and prognostic significance.. The assay relies upon the acquisition and construction of a patient's unique molecular genetic profiles from the DNA obtained from a tumor or lymph node. A patient' blood samples is then screened for the presence of cell tumor DNA fragments (ctDNA). It may detect new clonal .mutations as well. A high ctDNA score is indicative of recurrent/residual disease and potentiall a worse prognosisis. Your oncology team can use the information provided by the assay to adjust/modify/ change your therapeutic regimens to hopefully slow the progress of your disease.
There are a number of similar, if not superior offerings to Signatera from other clinical labs such as Quest's recently launched,Haystack MRD test, Guardant 360 MRD test, Circulogene's ctDNA/RNA test among others. All of these assays have minor variations in their respective sample prep, analyses and reporting of results. All appear to offer similar levels of sensitivity, specificity and prognostic significance as well as similar pricing. Their respective turn around times for reporting test results is variable, but is usually ~2 weeks.

My oncologist recommended Guardant Reveal and I have done 4 tests and all have been negative- yay 🙏🏼and I will continue doing Guardant Reveal every 3-4 months. Highly recommend 🥰

I have a CT scan with contrast every three months and just want to say to you: don’t be afraid of it - it’s not a big deal. Here in Ireland you go in, sip 2 pints of contrast liquid in the waiting room within an hour, then get the needle into your arm and then go into the machine. Much quicker than a MRI, a warm sensation when another contrast liquid is put through you intravenously and you’re done! Nothing to it

Hi. I’m not sure why this post is in this discussion. The Signatera test is a blood test not an imaging test. But since it’s here I’d like to ask about the 2 pints of contrast liquid you are drinking. I’ve had about a dozen Ct scans in Italy with the intravenous contrast but nothing to drink. Very curious.

I guess I was trying to comfort the lady who expressed anxiety about upcoming CT scan, so that’s why I mentioned it. I actually don’t know why we get the 2 pints, I see everyone in the waiting room drinking them. I didn’t know other countries don’t do the same. Maybe different CT machines? (Of course there are CT’s without contrast too.) I’ll ask at my next appointment ….

I can answer that. For my chest CT I only have IV contrast but I have to drink the liquid for my abdominal and pelvis CTs. They can do those with IV but the radiologist told me the liquid gives much better images for GI CTs.

Thank you very much. I understand the difference now.
Best wishes.

Thank you. Best wishes.